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Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 01-2018 trié par par titre, page: 0
» $lambda $ -Domain Optimal Bit Allocation Algorithm for High Efficiency Video Coding
Résumé:
Rate control typically involves two steps: bit allocation and bitrate control. The bit allocation step can be implemented in various fashions depending on how many levels of allocation are desired and whether or not an optimal rate–distortion (R-D) performance is pursued. The bitrate control step has a simple aim in achieving the target bitrate as precisely as possible. In our recent research, we have developed a $ {lambda }$ -domain rate control algorithm that is capable of controlling the bitrate precisely for High Efficiency Video Coding (HEVC). The initial research showed that the bitrate control in the $ {lambda }$ -domain can be more precise than the conventional schemes. However, the simple bit allocation scheme adopted in this initial research is unable to achieve an optimal R-D performance reflecting the inherent R-D characteristics governed by the video content. In order to achieve an optimal R-D performance, the bit allocation algorithms need to be developed taking into account the video content of a given sequence. The key issue in deriving the video-content-guided optimal bit allocation algorithm is to build a suitable R-D model to characterize the R-D behavior of the video content. In this paper, to complement the R- $ {lambda }$ model developed in our initial work, a D- $ {lambda }$ model is properly constructed to complete a comprehensive framework of $ {lambda }$ -domain R-D analysis. Based on this comprehensive $ {lambda }$ -domain R-D analysis framework, a suite of optimal bit allocation algorithms- are developed. In particular, we design both picture-level and basic-unit-level bit allocation algorithms based on the fundamental R-D optimization theory to take full advantage of the content-guided principles. The proposed algorithms are implemented in HEVC reference software, and the experimental results demonstrate that they can achieve an obvious R-D performance improvement with a smaller bitrate control error. The proposed bit allocation algorithms have already been adopted by the Joint Collaborative Team on Video Coding and integrated into the HEVC reference software.
Auteurs: Li Li;Bin Li;Houqiang Li;Chang Wen Chen;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 01.-2018, volume: 28, issue:1, pages: 130 - 142
Editeur: IEEE
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» $X$ -band DC–DC Power Converter for High-Speed Bit-Stream Modulation
Résumé:
This letter proposes an X-band power converter for high-speed bit-stream modulation. The converter consists of a power amplifier (PA) with pulsed load modulation, which performs highly efficient dc–ac conversion for a wide range of output powers, and a switching rectifier. Power conversion was performed in the X-band, and the potential for broad bandwidth and profile minimization was demonstrated. The PA was fabricated using a discrete gallium-nitride HEMT device and it delivered 39-dBm RF output power with 57.4% drain efficiency (DE) at 9.2 GHz under class-B conditions. At 6-dB output power back-off, 38.2% DE was measured for a 4 Gb/s data rate. The switching rectifier is designed using a class-B PA strategy to demonstrate the proposed concept. The ac–dc conversion efficiency was measured to be 44.6%, and 3.05-W dc power was delivered.
Auteurs: Yonghoon Song;Yuanxun Ethan Wang;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 46 - 48
Editeur: IEEE
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» γ-Ray Radiation Effects on an HfO2-Based Resistive Memory Device
Résumé:
In this paper, electrical characteristics of an HfO2-based resistive switching memory device are investigated before and after γ-ray radiation with various total ionizing doses (TIDs). The device can still function properly even if irradiated with a TID of 20 Mrad(Si). The small changes of resistance states and set/reset voltages induced by γ-ray radiation can hardly influence the proper function of the device. The γ-ray radiation does not significantly degrade both retention and endurance characteristics even after a high-TID exposure. The radiation effects on the resistive switching memory device show little dependence on the cell area. The results suggest that the HfO2-based resistive switching memory device has good γ-ray radiation-resistant capability.
Auteurs: Shaogang Hu;Yang Liu;Tupei Chen;Qi Guo;Yu-Dong Li;Xing-Yao Zhang;L. J. Deng;Qi Yu;You Yin;Sumio Hosaka;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 01.-2018, volume: 17, issue:1, pages: 61 - 64
Editeur: IEEE
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» (Perfect) Integer Codes Correcting Single Errors
Résumé:
This letter presents a class of integer codes capable of correcting single errors. Unlike Hamming codes, the presented codes are constructed with the help of a computer. Among all codes of length up to 4096 bits, a computer search has found four perfect codes: (15, 10), (63, 56), (1023, 1012), and (4095, 4082). In addition, it is shown that, for practical data lengths up to 4096 bits, the proposed codes require only one check bit more compared to Hamming codes.
Auteurs: Aleksandar Radonjic;
Apparue dans: IEEE Communications Letters
Date publication: 01.-2018, volume: 22, issue:1, pages: 17 - 20
Editeur: IEEE
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» 0.2-nJ/b Fast Start-Up Ultralow Power Wireless Transmitter for IoT Applications
Résumé:
Wireless transmitters (Tx) targeting Internet-of-things (IoT) applications impose tough end-to-end efficiency requirements. The frequency synthesis problem is usually solved by incorporating a variant of the phase-locked loop. However, power-hungry dividers and large loop time constants hurt the aggregated Tx power consumption and produce systems with slow start-up and turnaround times, particularly when operating at low output power. This paper demonstrates an agile ultralow power and energy-efficient transmitter architecture for IoT applications to address these concerns. The Tx leverages the characteristics of the wideband frequency-shift keying modulation and uses an openloop ring oscillator based on a vertical delay cell as its local oscillator (LO) generator. When followed by an edge-combiner-type power amplifier, the required LO operating frequency drops to one-third of the RF frequency, which further reduces the Tx power consumption. Moreover, LO frequency correction is achieved through a digitally assisted scheme with specially designed delay cells for fast frequency calibration. The Tx was fabricated in 0.18- $mu text {m}$ CMOS technology and occupies an active area of 0.112 mm2. The experimental results show a Tx energy efficiency of 0.2 nJ/b for a 3-Mb/s data rate and a normalized energy efficiency of 3.1 nJ/b $cdot $ mW when operating at a maximum output power of −10 dBm.
Auteurs: Jorge Zarate-Roldan;Amr Abuellil;Mo’men Mansour;Omar Elsayed;Faisal Abdel-Latif Hussien;Ahmed Eladawy;Edgar Sánchez-Sinencio;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 01.-2018, volume: 66, issue:1, pages: 259 - 272
Editeur: IEEE
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» 1.4Gsearch/s 2-Mb/mm2 TCAM Using Two-Phase-Pre-Charge ML Sensing and Power-Grid Pre-Conditioning to Reduce Ldi/dt Power-Supply Noise by 50%
Résumé:
This paper describes two power-supply noise (Ldi/dt) management techniques implemented in a 14-nm ternary content-addressable memory (TCAM) compiler that allows a $2text {K} times 640$ b instance to perform 1.4Gsearches/s while achieving a density of 2 Mb/mm2. This represents a 15% better performance and 10% better density than previous state-of-the-art TCAM. The first technique reduces the within-cycle noise by employing a two-phase match line (ML) pre-charge circuit which shuts off the pre-charge shoot-through current on easy-to-detect multi-bit mismatched MLs early in the cycle thereby approximately saving 60% of the ML power and reducing the within-cycle noise by 49.7%. The second technique is to reduce the multi-cycle noise by inserting targeted dummy search operations during low-current demand periods to flatten out current demand and reduce Ldi/dt noise by another 50%.
Auteurs: Igor Arsovski;Akhilesh Patil;Robert M. Houle;Michael T. Fragano;Ramon Rodriguez;Raymond Kim;Van Butler;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 155 - 163
Editeur: IEEE
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» 1.5–3.3 GHz, 0.0077 mm2, 7 mW All-Digital Delay-Locked Loop With Dead-Zone Free Phase Detector in $0.13~mu text{m}$ CMOS
Résumé:
A 1.5–3.3 GHz, 7 mW, all-digital delay-locked loop (ADDLL) designed in a UMC 130-nm CMOS technology is presented in this paper. The proposed ADDLL uses the modified successive approximation register to control a NAND-based coarse delay line, which enables wider operating frequency range and small intrinsic delay. The inverter-based fine delay line is controlled by an XOR-based up/down counter with dead-zone free phase detector to overcome the dead-zone problem of conventional phase detectors. The D-type flip-flops in the phase detector are modified to detect sub-ps level delay difference between the input and output clocks, so that a delay resolution of better than 1 ps is achieved in the proposed design. The combination of both coarse and fine locking processes gives outstanding performance in terms of residual phase difference and output jitter. The overall design occupies 0.0077 mm2 area. The experimental results show that the peak-to-peak and root mean square jitters are 12 and 1.629 ps at 3.3 GHz, respectively, while the input jitter is 2.6 ps peak-to-peak and 612 fs rms.
Auteurs: Erkan Bayram;Ahmed Farouk Aref;Mohamed Saeed;Renato Negra;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 01.-2018, volume: 65, issue:1, pages: 39 - 50
Editeur: IEEE
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» 14-nm FinFET Technology for Analog and RF Applications
Résumé:
This paper describes the features and performance of an analog and RF device technology development on a 14-nm logic FinFET platform. An optimized single-side gate contact RF device layout shows a ${F}_{t}/{F}_{text {max}}$ of 314/180 GHz and 285/140 GHz for ${N}$ and PFinFET device, respectively. The double-side gate contact structure with contact on either end of active gate enhances the peak ${F}_{text {max}}$ performance to 227 and 195 GHz for both ${N}$ and PFinFET devices, respectively. A significant boost in the PFinFET RF performance is observed compared to 28-nm planar PFET, which is attributed to the source/drain SiGe epitaxy stressor that results in higher hole carrier mobility. On the other hand, the thin channel body of FinFET structure facilitates a better electrostatic control of gate over the channel region and hence suppresses short channel effects including the drain-induced barrier lowering. Consequently, a significantly higher self-gain ( ${G}_{m}/{G}_{text {ds}})~40$ and 34 for both NFinFET and PFinFET is achieved. In addition, N/PFinFETs demonstrate superior 1/f noise of 17/35 fV $^{2}mu text{m}^{2}$ /Hz at 1 kHz compared to 171/106 fV $^{mathrm {mathbf {2}}}mu text{m}^{2}$ /Hz of 28-nm planar N/PFETs. To extend the low-voltage operation and power saving of FinFET RF platform, ultralow ${V}_{t}$ N/PFinFETs in the range of 50 mV ${V}_{t}text{s}$ are also developed. Furthermore, a deep n-well process is added to the platform to provide device and circuit isolation from substrate and supply noise, while realizing the creation of new devices such as vertical NPN, PCAP, and high breakdown voltage deep n-well junction diodes. Overall, a superior ${F}_{t}/{F}_{textsf {max}}$ , high self-gain, low 1/f noise, and robust substrate isolation characteristics extend the capability of this new 14-nm FinFET technology to the analog and RF circuit applications.
Auteurs: Jagar Singh;J. Ciavatti;K. Sundaram;J. S. Wong;A. Bandyopadhyay;X. Zhang;S. Li;A. Bellaouar;J. Watts;J. G. Lee;S. B. Samavedam;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 01.-2018, volume: 65, issue:1, pages: 31 - 37
Editeur: IEEE
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» 140 GHz High-Gain LTCC-Integrated Transmit-Array Antenna Using a Wideband SIW Aperture-Coupling Phase Delay Structure
Résumé:
This paper presents the complete design of a wideband transmit-array (TA) antenna with high gain and high efficiency for D-band applications based on the low-temperature co-fired ceramic technology. The proposed unit cell is composed of a pair of wideband magnetoelectric dipoles as the receive/transmit elements, together with a substrate-integrated waveguide (SIW) aperture-coupling transmission structure for independent phase adjustability. A 360° phase coverage is obtained by the proposed phasing element, and its phase response curves are nearly parallel within a broad frequency band, which indicates a wideband performance. To verify the design, the fabricated prototype is measured by using a vector network analyzer in a terahertz compact-range anechoic chamber. The measured peak gain is 33.45 dBi at 150 GHz with the aperture efficiency of 44.03%, and the measured 3 dB gain bandwidth is 124–158 GHz (24.29%). The good radiation performance ensures that the proposed SIW aperture-coupling TA antenna is a promising candidate for D-band applications.
Auteurs: Zhuo-Wei Miao;Zhang-Cheng Hao;Guo Qing Luo;Liang Gao;Jie Wang;Xiao Wang;Wei Hong;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 01.-2018, volume: 66, issue:1, pages: 182 - 190
Editeur: IEEE
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» 15 kV-Class Implantation-Free 4H-SiC BJTs With Record High Current Gain
Résumé:
Implantation-free mesa-etched ultra-high-voltage (0.08 mm2) 4H-SiC bipolar junction transistors (BJTs) with record current gain of 139 are fabricated, measured, and analyzed by device simulation. High current gain is achieved by optimized surface passivation and optimal cell geometries. The area-optimized junction termination extension is utilized to obtain a high and stable breakdown voltage without ion implantation. The open-base blocking voltage of 15.8 kV at a leakage current density of 0.1 mA/cm2 is achieved. Different cell geometries (single finger, square, and hexagon cell geometries) are also compared.
Auteurs: Arash Salemi;Hossein Elahipanah;Keijo Jacobs;Carl-Mikael Zetterling;Mikael Östling;
Apparue dans: IEEE Electron Device Letters
Date publication: 01.-2018, volume: 39, issue:1, pages: 63 - 66
Editeur: IEEE
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» 15-dB Differential Link-Loss UDWDM-PON With Direct Beat Phase Modulated DFBs
Résumé:
A 15 dB differential link-loss ultra-dense wavelength division multiplexing passive optical network (UDWDM-PON) with two optical network units (ONU) spectrally spaced 6.25 GHz is experimentally implemented and tested. The ONU transmitters consist of direct phase modulated distributed feedback lasers through a digital beat signal, whose amplitude and duty cycle are optimized for maximum phase variations, avoiding the need for an analogue equalizer. We achieved receiver sensitivities of −53, −50.5, and −45 dBm for bit rates of 1.25, 2.5, and 5 Gb/s, respectively, at BER $= 4~cdot ~10^{-3}$ with an intradyne coherent receiver.
Auteurs: J. Camilo Velásquez;Iván N. Cano;Victor Polo;Marc Domingo;Josep Prat;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 01.-2018, volume: 30, issue:2, pages: 137 - 140
Editeur: IEEE
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» 2- and 3-D Urban Change Detection With Quad-PolSAR Data
Résumé:
In this letter, an unsupervised 2-D and 3-D urban change detection scheme is proposed exploiting Quad-PolSAR data. Changes are extracted by segmenting the data into superpixels, to enhance the balance among change components and increase estimability of prior distributions. Positive and negative change components for built-up areas, in both the horizontal and the vertical directions, are properly extracted by assuming a multivariate Gaussian mixed model applied to a subset of polarimetric parameters at the superpixel level. The proposed method is tested on multitemporal Quad-PolSAR images and the results confirm its effectiveness. The selection of polarimetric decomposition measures that are most useful to the task is also experimentally justified.
Auteurs: Meiqin Che;Peijun Du;Paolo Gamba;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 01.-2018, volume: 15, issue:1, pages: 68 - 72
Editeur: IEEE
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» 2-D Analytical Drain Current Model of Double-Gate Heterojunction TFETs With a SiO2/HfO2 Stacked Gate-Oxide Structure
Résumé:
A continuous 2-D analytical drain current model of double-gate (DG) heterojunction tunnel field-effect transistors (HJTFETs) with a SiO2/HfO2 stacked gate-oxide structures has been presented in this paper. The surface potential model has been developed by considering the effect of accumulation/inversion charges and depletion region at source/channel and drain/channel junctions. The electric field-dependent band-to-band tunneling generation rate has been derived from the surface potential model. The tangent line approximation method has been used to calculate the drain current of DG HJTFETs. The developed model is valid for all regions (subthreshold to strong accumulation/inversion region) of operation. The model has been developed for Si/Ge hetero and Si homojunction-based tunnel field-effect transistor devices. The model is also applicable for other structures such as III–V materials-based InAs/GaSb DG HJTFET and silicon-on-insulator-based HJTFET. The analytical model results are validated by 2-D ATLAS simulation data.
Auteurs: Sanjay Kumar;Kunal Singh;Sweta Chander;Ekta Goel;Prince Kumar Singh;Kamalaksha Baral;Balraj Singh;Satyabrata Jit;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 01.-2018, volume: 65, issue:1, pages: 331 - 338
Editeur: IEEE
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» 2.4 GHz Class- $text{F}^{-1}$ GaN Doherty Amplifier With Efficiency Enhancement Technique
Résumé:
An enhancement in the efficiency of an inverse Class F (Class $text{F}^{-1})$ Doherty power amplifier (DPA) using a proposed triple-level supply modulator (SM) is presented. A three-level SM provides a lower supply voltage at a low input voltage, while providing the maximum level beyond the power back off. By adjusting the supply voltage in terms of the magnitude of the input signal, the efficiency of the main amplifier of the DPA over a wide input range is extended. For verification, a 2.4-GHz GaN Class $text{F}^{-1}$ DPA was designed and fabricated. Using a 10 MHz 8.6 dB peak-to-average power ratio signal, at an average output power of 34.1 dBm, the fabricated Class $text{F}^{-1}$ DPA achieves an efficiency level of 49%, which is 7.1% higher than that of a conventional amplifier. Under this condition, the measured adjacent channel leakage ratio (ACLR) is below −30 dBc.
Auteurs: Joonhyung Kim;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 34 - 36
Editeur: IEEE
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» 2017 General Meeting: A More Secure, Resilient, & Adaptable Grid [Society News]
Résumé:
Auteurs: D.F. Hall;
Apparue dans: IEEE Power and Energy Magazine
Date publication: 01.-2018, volume: 16, issue:1, pages: 66 - 68
Editeur: IEEE
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» 3-D Floating-Gate Synapse Array With Spike-Time-Dependent Plasticity
Résumé:
This paper proposes a 3-D floating-gate (FG) synapse array for neuromorphic applications. The designed device has certain advantages over previous planar FG synapse devices: a smaller cell size due to the stacked structure and smaller operation voltage by the gate-all-around geometry. In addition, the operation method to implement spike time-dependent plasticity is proposed and demonstrated. The proposed array based on commercialized flash memory technology is expected be one of the most promising candidate architecture for neuromorphic applications.
Auteurs: Hyun-Seok Choi;Dae-Hoon Wee;Hyungjin Kim;Sungjun Kim;Kyung-Chang Ryoo;Byung-Gook Park;Yoon Kim;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 01.-2018, volume: 65, issue:1, pages: 101 - 107
Editeur: IEEE
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» 3-D Microwave Holographic Imaging With Probe and Phase Compensations
Résumé:
A 3-D microwave holographic imaging algorithm compatible with reflection-coefficient measurement setup is proposed. It can be divided into four parts. First, starting from the open-circuit voltage of antenna, the algorithm compensates for both transmitting and receiving properties of the probe antenna, leading to antenna-independent least squares problems. However, the problems tend to be ill-conditioned. An auxiliary equation is thus derived and exploited to effectively improve the numerical stability and image quality. Third, to accurately locate the unknown target in range direction, a phase compensation method that requires only phase correction to the associated entries of the kernel matrix is proposed based on a simple ray model. Last, considering the finite size of the scanning aperture and beamwidth of the probe antenna, a numerical low-pass filter in the spatial-frequency domain is utilized to effectively locate the worth-solving area. For verification, a series of images reconstructed from the simulated and measured data using the proposed algorithm are presented. Thanks to the enhanced image quality, the geometry, location, and dielectric constant of the target can be retrieved. The range and cross-range resolutions achieved are about $lambda /10$ and $lambda /4$ , respectively.
Auteurs: Cheng-Hao Tsai;Jinjia Chang;Liang-Yu Ou Yang;Shih-Yuan Chen;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 01.-2018, volume: 66, issue:1, pages: 368 - 380
Editeur: IEEE
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» 3-D Surround View for Advanced Driver Assistance Systems
Résumé:
As the primary means of transportations in modern society, the automobile is developing toward the trend of intelligence, automation, and comfort. In this paper, we propose a more immersive 3-D surround view covering the automobiles around for advanced driver assistance systems. The 3-D surround view helps drivers to become aware of the driving environment and eliminates visual blind spots. The system first uses four fish-eye lenses mounted around a vehicle to capture images. Then, according to the pattern of image acquisition, camera calibration, image stitching, and scene generation, the 3-D surround driving environment is created. To achieve the real-time and easy-to-handle performance, we only use one image to finish the camera calibration through a special designed checkerboard. Furthermore, in the process of image stitching, a 3-D ship model is built to be the supporter, where texture mapping and image fusion algorithms are utilized to preserve the real texture information. The algorithms used in this system can reduce the computational complexity and improve the stitching efficiency. The fidelity of the surround view is also improved, thereby optimizing the immersion experience of the system under the premise of preserving the information of the surroundings.
Auteurs: Yi Gao;Chunyu Lin;Yao Zhao;Xin Wang;Shikui Wei;Qi Huang;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 01.-2018, volume: 19, issue:1, pages: 320 - 328
Editeur: IEEE
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» 4 strange new ways to compute [News]
Résumé:
With Moore's Law slowing down, engineers have been taking a hard look at what will keep computing going when the law is no more. Certainly, artificial intelligence will play a role. So might quantum computing. But there are stranger things in the computing universe, and some of them got an airing at the IEEE International Conference on Rebooting Computing, in November. There were cool variations on classics such as reversible computing and neuromorphic chips. Less-familiar concepts got their time in the sun, too, such as photonics chips that accelerate artificial intelligence, nanomechanical comb-shaped logic, and a "hyperdimensional" speech recognition system. What follows includes a taste of both the strange and the potentially powerful.
Auteurs: Samuel K. Moore;
Apparue dans: IEEE Spectrum
Date publication: 01.-2018, volume: 55, issue:1, pages: 10 - 11
Editeur: IEEE
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» 4.32-pJ/b, Overlap-Free, Feedforward Edge-Combiner-Based Ultra-Wideband Transmitter for High-Channel-Count Neural Recording
Résumé:
We present an ultralow-power, ultra-wideband (UWB) transmitter (TX) in standard 65-nm CMOS processes. The TX consists of feedforward edge combiners and interpolators for ultralow-power operation and reliable pulse generation that is essential in UWB TXs. The implemented circuit avoids pulse overlapping without complicated calibrations and has achieved an energy efficiency of 4.32 pJ/b at 200-Mbps data rate. The TX is suitable for energy-constraint, high-data-rate applications such as wireless telemetry in implantable high-density neural recording interfaces.
Auteurs: Yu-Ju Lin;Sung-Yun Park;Xing Chen;David Wentzloff;Euisik Yoon;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 52 - 54
Editeur: IEEE
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» 5G goes for the gold
Résumé:
Welcome to the 5G Olympics, where Nathan Chen, the 18-year-old figure-skating phenom, has just landed another quadruple jump. Can't see him well from your seat in the nosebleed section? No problem. Just slip on your 5G virtual reality headset for a 360-degree rink-side view! Now watch your step-we're boarding the 5G bus to the next attraction. Check out the windows: They're in fact transparent display screens providing ultrahigh-definition video—streamed live—from a hockey player's headcam, from drones flying above the ski slopes, and from the cockpit of a bobsled barreling down an icy track at 100...0...0 kilometers per hour!
Auteurs: Ariel Bleicher;
Apparue dans: IEEE Spectrum
Date publication: 01.-2018, volume: 55, issue:1, pages: 32 - 33
Editeur: IEEE
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» In Vitro Evaluation of an Injectable EEG/ECG Sensor for Wireless Monitoring of Hibernation in Endangered Animal Species
Résumé:
Hibernation is a unique metabolic adaptation employed by several animal species for survival where its study would further enhance our understanding of metabolic disorders, such as diabetes and obesity. As a primate animal with close genetic ties to humans, the recent discovery of hibernation in dwarf lemurs of Madagascar has attracted the attention of researchers. Traditional recording systems require the physical tethering of the animals to the recording apparatus or the use of implantable devices. Scalp and needle electrodes interfere with the natural hibernation process and limit the continuity of the experiments, while invasive procedures are banned on endangered species. By integrating a full-wave rectifier, low-noise signal conditioning circuit, frequency modulation transmitter, and antenna in a single application specific integrated circuit (ASIC), we have developed an ultra-miniaturized wireless system that measures $34 times 4 times 2.6$ mm3 in volume. It only requires three off-chip components (a coil wound around a ferrite rod and two external capacitors) to be powered wirelessly through a 1-MHz inductive link, such that it can be packaged inside a glass or polymer capsule and injected subcutaneously underneath the scalp or chest without requiring a surgery, thereby addressing the shortcomings of the traditional monitoring systems. Our recording device provides an input/output correlation coefficient greater than 80% for input amplitudes ranging from 60 to 260 $mu V_{mathrm{ pp}}$ , with a wireless data transmission range of ~2.5 cm while operating near the 902–928 MHz ISM frequency band. This system would enable future studies of electroencephalography and electrocardiography in hibernating dwarf lemurs. The ASIC was fabricated using the O- Semiconductor 0.5- $mu text{m}$ CMOS process with an active area of 2.5 $times $ 1 mm2 and has a power consumption of 7.75 mW from a 3.1 V supply. In this paper, we demonstrate the in vitro functionality of the system using simulated physiological signals directly applied to the ASIC or through standard stainless steel electrodes immersed in saline solution.
Auteurs: Jose Manuel Valero-Sarmiento;James Reynolds;Andrew Krystal;Alper Bozkurt;
Apparue dans: IEEE Sensors Journal
Date publication: 01.-2018, volume: 18, issue:2, pages: 798 - 808
Editeur: IEEE
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» In Vivo Superresolution Imaging of Neuronal Structure in the Mouse Brain
Résumé:
Objective: this study proposes and evaluates a technique for in vivo deep-tissue superresolution imaging in the light-scattering mouse brain at up to a 3.5 Hz 2-D imaging rate with a 21×21 μm2 field of view. Methods: we combine the deep-tissue penetration and high imaging speed of resonant laser scanning two-photon (2P) microscopy with the superresolution ability of patterned excitation microscopy. Using high-frequency intensity modulation of the scanned two-photon excitation beam, we generate patterned illumination at the imaging plane. Using the principles of structured illumination, the high-frequency components in the collected images are then used to reconstruct images with an approximate twofold increase in optical resolution. Results: using our technique, resonant 2P superresolution patterned excitation reconstruction microscopy, we demonstrate our ability to investigate nanoscopic neuronal architecture in the cerebral cortex of the mouse brain at a depth of 120 μm in vivo and 210 μm ex vivo with a resolution of 119 nm. This technique optimizes the combination of speed and depth for improved in vivo imaging in the rodent neocortex. Conclusion: this study demonstrates a potentially useful technique for superresolution in vivo investigations in the rodent brain in deep tissue, creating a platform for investigating nanoscopic neuronal dynamics. Significance : this technique optimizes the combination of speed and depth for improved superresolution in vivo imaging in the rodent neocortex.
Auteurs: Ben Ewell Urban;Lei Xiao;Siyu Chen;Huili Yang;Biqin Dong;Yevgenia Kozorovitskiy;Hao F. Zhang;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 01.-2018, volume: 65, issue:1, pages: 232 - 238
Editeur: IEEE
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» PhLock: A Cache Energy Saving Technique Using Phase-Based Cache Locking
Résumé:
Caches are commonly used to bridge the processor-memory performance gap in embedded systems. Since embedded systems typically have stringent design constraints imposed by physical size, battery capacity, and real-time deadlines much research focuses on cache optimizations, such as improved performance and/or reduced energy consumption. Cache locking is a popular cache optimization that loads and retains/locks selected memory contents from an executing application into the cache to increase the cache’s predictability. Previous work has shown that cache locking also has the potential to improve cache energy consumption. In this paper, we introduce phase-based cache locking, PhLock, which leverages an application’s varying runtime characteristics to dynamically select the locked memory contents to optimize cache energy consumption. Using a variety of applications from the SPEC2006 and MiBench benchmark suites, experimental results show that PhLock is promising for reducing both the instruction and data caches’ energy consumption. As compared to a nonlocking cache, PhLock reduced the instruction and data cache energy consumption by an average of 5% and 39%, respectively, for SPEC2006 applications, and by 75% and 14%, respectively, for MiBench benchmarks.
Auteurs: Tosiron Adegbija;Ann Gordon-Ross;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 01.-2018, volume: 26, issue:1, pages: 110 - 121
Editeur: IEEE
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» Post Hoc Analysis of Passive Cavitation Imaging for Classification of Histotripsy-Induced Liquefaction in Vitro
Résumé:
Histotripsy utilizes focused ultrasound to generate bubble clouds for transcutaneous tissue liquefaction. Bubble activity maps are under development to provide image guidance and monitor treatment progress. The aim of this paper was to investigate the feasibility of using plane wave B-mode and passive cavitation images to be used as binary classifiers of histotripsy-induced liquefaction. Prostate tissue phantoms were exposed to histotripsy pulses over a range of pulse durations (5– $20~mu text{s}$ ) and peak negative pressures (12–23 MPa). Acoustic emissions were recorded during the insonation and beamformed to form passive cavitation images. Plane wave B-mode images were acquired following the insonation to detect the hyperechoic bubble cloud. Phantom samples were sectioned and stained to delineate the liquefaction zone. Correlation between passive cavitation and plane wave B-mode images and the liquefaction zone was assessed using receiver operating characteristic (ROC) curve analysis. Liquefaction of the phantom was observed for all the insonation conditions. The area under the ROC (0.94 versus 0.82), accuracy (0.90 versus 0.83), and sensitivity (0.81 versus 0.49) was greater for passive cavitation images relative to B-mode images ( ${p} < 0.05$ ) along the azimuth of the liquefaction zone. The specificity was greater than 0.9 for both imaging modalities. These results demonstrate a stronger correlation between histotripsy-induced liquefaction and passive cavitation imaging compared with the plane wave B-mode imaging, albeit with limited passive cavitation image range resolution.
Auteurs: Kenneth B. Bader;Kevin J. Haworth;Adam D. Maxwell;Christy K. Holland;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 01.-2018, volume: 37, issue:1, pages: 106 - 115
Editeur: IEEE
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» SparseLeap: Efficient Empty Space Skipping for Large-Scale Volume Rendering
Résumé:
Recent advances in data acquisition produce volume data of very high resolution and large size, such as terabyte-sized microscopy volumes. These data often contain many fine and intricate structures, which pose huge challenges for volume rendering, and make it particularly important to efficiently skip empty space. This paper addresses two major challenges: (1) The complexity of large volumes containing fine structures often leads to highly fragmented space subdivisions that make empty regions hard to skip efficiently. (2) The classification of space into empty and non-empty regions changes frequently, because the user or the evaluation of an interactive query activate a different set of objects, which makes it unfeasible to pre-compute a well-adapted space subdivision. We describe the novel SparseLeap method for efficient empty space skipping in very large volumes, even around fine structures. The main performance characteristic of SparseLeap is that it moves the major cost of empty space skipping out of the ray-casting stage. We achieve this via a hybrid strategy that balances the computational load between determining empty ray segments in a rasterization (object-order) stage, and sampling non-empty volume data in the ray-casting (image-order) stage. Before ray-casting, we exploit the fast hardware rasterization of GPUs to create a ray segment list for each pixel, which identifies non-empty regions along the ray. The ray-casting stage then leaps over empty space without hierarchy traversal. Ray segment lists are created by rasterizing a set of fine-grained, view-independent bounding boxes. Frame coherence is exploited by re-using the same bounding boxes unless the set of active objects changes. We show that SparseLeap scales better to large, sparse data than standard octree empty space skipping.
Auteurs: Markus Hadwiger;Ali K. Al-Awami;Johanna Beyer;Marco Agus;Hanspeter Pfister;
Apparue dans: IEEE Transactions on Visualization and Computer Graphics
Date publication: 01.-2018, volume: 24, issue:1, pages: 974 - 983
Editeur: IEEE
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» X-Band Microwave Absorbing Properties of Epoxy Resin Composites Containing Magnetized PANI-Coated Magnetite
Résumé:
Magnetized (PANI-coated Fe3O4) epoxy resin was synthesized to produce $X$ -band microwave absorbing structures (MASs) with tuning thickness and fillers ratio. The structure and crystallinity of materials were checked by SEM and X-ray diffraction. It was found that the thickness, amount, and ratio of magnetized PANI-coated Fe3O4 affect the microwave absorption properties. Single layer MAS with 3 mm showed a reflection loss (RL) of −54 dB at 8.73 GHz and −41 dB at 9.52 GHz. However, a double-layer absorber based on 0.9 mm of the matching layer of PANI and the absorbing layer of magnetized (PANI-coated Fe3O4) epoxy resin composite with a thickness of 1.8 mm show a minimum RL value of −38 dB at 9.82 GHz and an absorption bandwidth of about 3.55 GHz with RL below −10 dB. In addition, by rising thicknesses the RL peak shift to lower frequency. A materials prepared with thin double-layer structure have a high absorption performances and broader bandwidth in $X$ -band.
Auteurs: Belkacem Belaabed;Saad Lamouri;Jean Luc Wojkiewicz;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 01.-2018, volume: 54, issue:1, pages: 1 - 8
Editeur: IEEE
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» A $V$ -band 90-nm CMOS Divide-by-10 Injection-Locked Frequency Divider Using Current-Reused Topology
Résumé:
A $V$ -band 90-nm CMOS divide-by-10 injection-locked frequency divider (ILFD) is proposed using current-reused topology in this letter. The proposed circuit is composed of a divide-by-5 ILFD and a source injection current-mode logic (SICML) divide-by-2 frequency divider. The cascoded topology of SICML and ILFD is employed to reduce dc power consumption and increase frequency division ratio. With an input power of 0 dBm, the measured maximum locking range (LR) is 5 GHz from 60.3 to 65.3 GHz. Compared with the reported CMOS microwave and millimeter-wave ILFDs, the proposed ILFD features wide LR, good sensitivity, and a high division ratio of up to ten.
Auteurs: Shen-Ming Li;Han-Nong Yeh;Hong-Yeh Chang;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 76 - 78
Editeur: IEEE
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» A 0.55-V, 28-ppm/°C, 83-nW CMOS Sub-BGR With UltraLow Power Curvature Compensation
Résumé:
This paper proposes an ultralow power, high precision sub bandgap voltage reference (sub-BGR) for low-voltage self-powered devices. A novel ultralow power curvature compensation circuit is proposed to improve the temperature coefficient over a wide temperature range. A switch capacitor voltage divider with improved leakage current reduction switches is used to obtain a high accuracy and a low power. To minimize the clock feedthrough and charge injection in the switches, a clock scaling down circuit is proposed, that effectively improves the line sensitivity (LS) of the sub-BGR. The proposed sub-BGR is implemented in a 0.18- $mu text{m}$ standard CMOS process with a total area of 0.061 mm2. After measuring 30 chips, the average power consumption is 83 nW at 0.55 V of supply at 27 °C. In the supply voltage range of 0.55 to 1 V, the LS is 0.059%/V, and the error is ±0.75% ( $3sigma $ ) after trimming.
Auteurs: Lianxi Liu;Junchao Mu;Zhangming Zhu;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 01.-2018, volume: 65, issue:1, pages: 95 - 106
Editeur: IEEE
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» A 0.7–2.5 GHz, 61% EIRP System Efficiency, Four-Element MIMO TX System Exploiting Integrated Power-Relaxed Power Amplifiers and an Analog Spatial De-Interleaver
Résumé:
This paper describes a four-element multiple-input multiple-output (MIMO) transmitter (TX) system that features an analog spatial de-interleaver to simplify the baseband-input complexity and increase the spatial matching of the sub-TXs. The MIMO diversity gain and power-combining gain are jointly exploited to relax the output power of the four power amplifiers and eliminate their output matching networks, leading to a compact implementation of the entire TX system. The MIMO effectiveness is improved by introducing an radio-frequency to baseband dc feedback technique that enhances the matching among the sub-TXs against process variation. In the verification, the TX system is co-designed with a compact antenna array-on-PCB that generates a null zone in the propagation pattern, and the electric-field polarization angle, to achieve diversity propagation. All techniques together improve the signal-to-noise ratio or data rate by generating multiple data streams according to the signal power arriving at the receiver over different fading channels. The four-element TX chip fabricated in 65-nm CMOS occupies a die area of 1.44 mm2. It covers an RF range of 0.7–2.5 GHz, and shows an equivalent isotropically radiated power of 23.9 dBm. When transmitting a 20-MHz 64-QAM orthogonal frequency division multiplexing signal at 2.3 GHz, the average system efficiency is 61% and error-vector magnitude is −26 dB.
Auteurs: Wei-Han Yu;Ka-Fai Un;Pui-In Mak;Rui P. Martins;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 01.-2018, volume: 65, issue:1, pages: 14 - 25
Editeur: IEEE
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» A 1-V 10-Gb/s/pin Single-Ended Transceiver With Controllable Active-Inductor-Based Driver and Adaptively Calibrated Cascaded-Equalizer for Post-LPDDR4 Interfaces
Résumé:
A 1-V 10-Gb/s/pin single-ended transceiver with a controllable active inductor-based output driver and adaptively calibrated cascaded-equalizer with infinite impulse response and finite impulse response filters for a post-LPDDR4 interface in a 65-nm CMOS technology is proposed. The proposed cascaded-equalizer removes the received long-tail inter symbol interference with the help of an IIR filter while the coefficients for the cascaded-equalizer are adaptively calibrated. In addition, the received single-ended ground-terminated data are converted to the differential pair by the proposed input buffer using a calibrated reference voltage. In the transmitter (TX), an output driver with controllable active inductors is proposed to reduce both power consumption and design complexity. At the maximum operating data rate, the measured power efficiencies of TX and receiver are 1.16 and 3.02 pJ/b, respectively, excluding the power dissipation of internal phase locked loop. In addition, the overall active area is 0.0091 mm2.
Auteurs: Junyoung Song;Sewook Hwang;Hyun-Woo Lee;Chulwoo Kim;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 01.-2018, volume: 65, issue:1, pages: 331 - 342
Editeur: IEEE
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» A 1.8-V 6.9-mW 120-fps 50-Channel Capacitive Touch Readout With Current Conveyor AFE and Current-Driven $Delta Sigma $ ADC
Résumé:
This paper presents an area- and energy-efficient readout for capacitive touch sensors. An analog front end (AFE) with current conveyor mitigates the requirements of front-end opamp and provides a differential current from adjacent channels, removing sensor’s baseline and interferences. The sensing current from the AFE is directly digitized by a current-driven 2nd-order $Delta Sigma $ analog-to-digital converter and its direct interfacing with the current signal achieves high signal-to-noise ratio (SNR) without suffering voltage saturation in the AFE, and provides reconfigurable SNRs and frame rates with respect to oversampling ratio. An area-efficient sinc2 filter, whose filter coefficients are commonly provided, enables full parallel implementation of $Delta Sigma $ ADCs. A 50-channel prototype IC is fabricated in a 0.18- $mu text{m}$ CMOS process, occupying only 1.96 mm2. Using a 10.1-in $28 times 50$ touch screen panel and a 3.3-V transmitter, this work achieves SNRs of 53.3 and 41.7 dB with finger and 1-mm- $phi $ stylus, respectively, while drawing only 6.9 mW from 1.8-V supply at 120 fps. This results in the state-of-the-art figure-of-merit of 0.11 and 0.41 nJ/step for finger and 1-mm- $phi $ stylus, respectively. Moreover, 500-dpi on-glass fingerprint sensor is verified with the same prototype IC and 15-V transmitter, and $70 times 50$ fingerprint image is successfully captured with 150- $mu text{m}$ cover glass.
Auteurs: Hyunseok Hwang;Hyeyeon Lee;Myungjin Han;Hongchae Kim;Youngcheol Chae;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 204 - 218
Editeur: IEEE
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» A 1.8e $^{-}_{mathrm {rms}} $ Temporal Noise Over 110-dB-Dynamic Range 3.4 $mu text{m}$ Pixel Pitch Global-Shutter CMOS Image Sensor With Dual-Gain Amplifiers SS-ADC, Light Guide Structure, and Multiple-Accumulation Shutter
Résumé:
A 1.8e $^{-}_{mathrm {rms}} $ temporal noise over 110 dB dynamic range 3.4 $mu text{m}$ pixel pitch global shutter (GS) CMOS image sensor (CIS) single-slope analog digital converters (ADCs) with dual-gain amplifier (SSDG-ADC), light guide (LG) structure, and multiple-accumulation shutter has been developed for various accuracy required applications. The newly developed CIS pixel achieves low noise, high saturation, high sensitivity, and high frame rate with seamless GS function. Low noise, high saturation, and high frame rate are realized by small photodiode, large charge-domain memory, and seamless multiple-accumulation readout procedure with SSDG-ADC. Furthermore, high sensitivity is realized by the optimized shape LG structure. The GS CIS is fabricated in a 130 nm 1Poly-Si 4Metal with light shield CMOS process. This image sensor achieves 1.8e $^{-}_{mathrm {rms}} $ temporal noise, 16 200e full-well capacity with 60 fps multiple-accumulation and 28 000e/lx $cdot text{s}$ sensitivity. This image sensor also realizes high-dynamic range readout procedure and in-pixel coded exposure for deblurred images. We also describe the examination results about the relationship of the sensitivity, parasitic light sensitivity, and LG structure.
Auteurs: Masahiro Kobayashi;Yusuke Onuki;Kazunari Kawabata;Hiroshi Sekine;Toshiki Tsuboi;Takashi Muto;Takeshi Akiyama;Yasushi Matsuno;Hidekazu Takahashi;Toru Koizumi;Katsuhito Sakurai;Hiroshi Yuzurihara;Shunsuke Inoue;Takeshi Ichikawa;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 219 - 228
Editeur: IEEE
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» A 173 GHz Amplifier With a 18.5 dB Power Gain in a 130 nm SiGe Process: A Systematic Design of High-Gain Amplifiers Above $f_{max }/2$
Résumé:
A novel theory of stability for two-port networks is developed. Using this theory, a new method of designing amplifiers with a high-power gain working close to the maximum frequency of oscillation ( $f_{max }$ ) is proposed. Contrary to the existing amplifier design methodologies, in this method, the transistor capability of power amplification is fully utilized. This becomes more important at frequencies close to the $f_{max }$ where having a high-power gain is challenging due to the degraded activity of the employed device. The proposed method considers the modeling errors and process–voltage–temperature variations of the employed components in the design stage to ensure that the fabricated amplifier will be stable with a decent power gain even if the worst case variations and modeling errors happen. To show the feasibility of the proposed approach, a three-stage amplifier at 173 GHz, using bipolar junction transistors from a 130 nm SiGe process, is designed. The fabricated amplifier has a maximum measured power gain of 18.5 dB at 173 GHz. A similar three-stage amplifier using the same transistors with the same bias would give a maximum gain of 6.8 dB in simulation, assuming perfect lossless conjugate matching at input, output, and between stages. So it is clear that the fabricated amplifier achieves a significant improvement over the power gain.
Auteurs: Hamid Khatibi;Somayeh Khiyabani;Ehsan Afshari;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 01.-2018, volume: 66, issue:1, pages: 201 - 214
Editeur: IEEE
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» A 1920 $times $ 1080 30-frames/s 2.3 TOPS/W Stereo-Depth Processor for Energy-Efficient Autonomous Navigation of Micro Aerial Vehicles
Résumé:
This paper presents a single-chip, high-performance, and energy-efficient stereo vision depth-estimation processor for micro aerial vehicles (MAVs). The proposed processor implements the state-of-the-art semi-global matching (SGM) algorithm to deliver full high-definition (HD, 1920 ${times }$ 1080) stereo-depth outputs with a maximum of 38 frames/s throughput. Algorithm-architecture co-optimization is conducted, introducing overlapping block-based processing that eliminates very large on-chip memory and off-chip DRAM. We exploit inherent data parallelism in the algorithm by processing 128 local disparity costs and aggregating the SGM costs along four paths for all 128 disparities in parallel. A dependence-resolving scan associated with 16-stage deep pipeline is introduced to hide the data dependence between neighboring pixels in the SGM algorithm. Moreover, we propose a customized ultra-high bandwidth dual-port SRAM that utilizes the unique memory access characteristic of SGM to achieve highly energy-efficient memory access at a very high on-chip memory bandwidth of 1.64 Tb/s. The fabricated processor produces 512 levels of depth information for each pixel at full HD resolution with 30-frames/s performance, consuming 836 mW from a 0.75-V supply in TSMC 40-nm GP CMOS. We ported the design on a quadcopter MAV to demonstrate its performance in realistic real-time flight.
Auteurs: Ziyun Li;Qing Dong;Mehdi Saligane;Benjamin Kempke;Luyao Gong;Zhengya Zhang;Ronald Dreslinski;Dennis Sylvester;David Blaauw;Hun-Seok Kim;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 76 - 90
Editeur: IEEE
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» A 2- $mu text{s}$ Fast-Response Step-Up Converter With Efficiency-Enhancement Techniques Suitable for Cluster-Based Wireless Sensor Networks
Résumé:
A new step-up (boost) converter with fast-response and efficiency-enhancement techniques suitable for cluster-based wireless sensor networks is presented in this paper. First, the modified nonoverlapping clock generator can produce four proper switching clocks to prevent four power transistors to be turned on simultaneously. Second, the size of the power transistor is adaptively changed by the width controller according to the different load current. Third, the zero-current detector is used to prevent the reverse inductor current at light load. Fourth, the converter efficiency can be raised by efficiency enhancement techniques. On top of that, this converter retains fast transient response at any load variation. The proposed boost converter has been implemented with a TSMC 0.35- $mu text{m}$ 2P4M CMOS 3.3/5 V process. The experimental results show that the proposed boost converter’s transient responses are $2~mu text {s}/4~mu text{s}$ for raising/falling time and the high efficiency is 93.8%.
Auteurs: Yuh-Shyan Hwang;Jiann-Jong Chen;Rong-Lian Shih;Yi-Tsen Ku;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 01.-2018, volume: 26, issue:1, pages: 216 - 220
Editeur: IEEE
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» A 2.1-Mpixel Organic Film-Stacked RGB-IR Image Sensor With Electrically Controllable IR Sensitivity
Résumé:
This paper describes an RGB-infrared (IR) organic CMOS image sensor with electrically controllable IR sensitivity. The sensitivities of all the pixels in the image sensor, which has the structure of two directly stacked organic layers with a high resistance ratio, are simultaneously controlled by changing the applied voltage to the organic films. The fabricated image sensor, with a pixel pitch of $3~mu text{m}$ , has 2.1 Mpixels (1920 $times $ 1080) in both the RGB and IR regions. The sensor can switch between color imaging and IR imaging modes frame by frame without requiring a mechanically retractable IR-cut filter.
Auteurs: Shin’ichi Machida;Sanshiro Shishido;Takeyoshi Tokuhara;Masaaki Yanagida;Takayoshi Yamada;Masumi Izuchi;Yoshiaki Sato;Yasuo Miyake;Manabu Nakata;Masashi Murakami;Mitsuru Harada;Yasunori Inoue;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 229 - 235
Editeur: IEEE
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» A 27 $mu text{W}$ 0.06 mm2 Background Resonance Frequency Tuning Circuit Based on Noise Observation for a 1.71 mW CT- $Delta Sigma $ MEMS Gyroscope Readout System With 0.9 °/h Bias Instability
Résumé:
This paper presents the implementation of a bandpass filter tuning circuit solely based on noise observation for a continuous-time (CT) delta–sigma modulator gyroscope readout system. By evaluating the noise at the electronic filter input, a filter frequency deviation of less than 50 Hz or approximately 0.5% of the gyroscope’s drive resonance frequency is achieved, which minimizes the angular rate noise floor. The automatic tuning works in the background during normal angular rate readout with input signals up to the full scale, over a temperature range of 115 °C, and with interference signals of up to −27.2 dBFS. The power (27 $mu text{W}$ ) and area (0.06 mm2) overhead to the overall system is less than 2%. The overall CT readout system achieves a noise floor of 0.002 °/s/ $sqrt {mathrm {Hz}}$ and a bias instability of 0.9 °/h while consuming only 1.71 mW.
Auteurs: Maximilian Marx;Daniel De Dorigo;Sebastian Nessler;Stefan Rombach;Yiannos Manoli;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 174 - 186
Editeur: IEEE
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» A 280-/300-GHz Three-Stage Amplifiers in 65-nm CMOS With 12-/9-dB Gain and 1.6/1.4% PAE While Dissipating 17.9 mW
Résumé:
This letter reports the design of terahertz amplifiers using the concept of maximum achievable gain ( $G_{mathrm {max}})$ of a transistor embedded in a linear, lossless, reciprocal network. Implemented in a 65-nm CMOS, by adopting the optimized $G_{mathrm {max}}$ -core, 280- and 300-GHz amplifiers achieve peak gain of 12 and 9 dB, peak power-added efficiency (PAE) of 1.6% and 1.4%, and gain per stage of 4 and 3 dB, respectively, while dissipating 17.9 mW, which is the best performance up to date in terms of operating frequency, gain per stage, and PAE in CMOS process.
Auteurs: Dae-Woong Park;Dzuhri Radityo Utomo;Bao Huu Lam;Jong-Phil Hong;Sang-Gug Lee;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 79 - 81
Editeur: IEEE
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» A 3-D Positioning Algorithm for AOA-Based VLP With an Aperture-Based Receiver
Résumé:
We consider a visible light positioning system using modulated LEDs at the transmitter and photodiodes (PDs) combined with apertures at the receiver. The layout of the aperture-based receiver is designed in order to have angular diversity, implying it can detect the direction from which light is coming, by simply comparing the relative differences in received signal strength values in the different PDs. Hence, with this receiver, it is possible to extract the angle-of-arrival (AOA) of the light without needing the knowledge of the transmitted optical power. In this paper, we consider an algorithm, based on the maximum likelihood (ML) principle, to estimate the AOA, and obtain the position of the receiver in 3-D through triangulation. The ML algorithm, of which the practical implementation searches for the optimal value of the AOA starting from an initial estimate, suffers from convergence problems if the initial estimate is too far from the true AOA. Hence, we propose an initial low-complexity coarse estimation algorithm for the AOA, and make the algorithm iterative, where in each iteration, the initial estimate for the AOA is updated based on the previous position estimate. We show that the algorithm yields centimeter performance, i.e., an accuracy of 10 cm or better, using a limited number of LEDs, e.g., four LEDs for a $5,,text {m} times 5$ m area.
Auteurs: Heidi Steendam;
Apparue dans: IEEE Journal on Selected Areas in Communications
Date publication: 01.-2018, volume: 36, issue:1, pages: 23 - 33
Editeur: IEEE
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» A 3.9-kHz Frame Rate and 61.0-dB SNR Analog Front-End IC With 6-bit Pressure and Tilt Angle Expressions of Active Stylus Using Multiple-Frequency Driving Method for Capacitive Touch Screen Panels
Résumé:
This paper proposes an analog front-end (AFE) IC using a multiple-frequency driving method (MFDM). The proposed AFE IC achieves a high signal-to-noise ratio (SNR) by using an external noise spectrum and locating the frequencies of the excitation signals in low-noise regions. In addition, it employs the MFDM to increase the frame rate by simultaneously sending excitation signals having multiple frequencies to the touch screen panel (TSP). The proposed AFE IC extracts the coordinates of the finger as well as the coordinates, pressure, and tilt angle of the active stylus with the force gauge and gyro sensor. The proposed AFE IC and active stylus were fabricated in a 0.13- $mu text{m}$ standard CMOS process. The measurement results show that the proposed AFE IC achieves a frame rate of 3.9 kHz, and SNRs of 61.0 and 50.1 dB when a finger and active stylus are used, respectively. In addition, the pressure and tilt angle of the active stylus are expressed with 6-bit resolution. A capacitive touch system with the proposed AFE IC is demonstrated with a 65-in $104times 64$ TSP using ten fingers and the active stylus with the pressure and tilt angle.
Auteurs: Jae-Sung An;Sang-Hyun Han;Ju Eon Kim;Dong-Hyun Yoon;Young-Hwan Kim;Han-Hee Hong;Jae-Hun Ye;Sung-Jin Jung;Seung-Hwan Lee;Ji-Yong Jeong;Kwang-Hyun Baek;Seong-Kwan Hong;Oh-Kyong Kwon;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 187 - 203
Editeur: IEEE
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» A 37- $mu text{W}$ , Binary-Weighted PGA Based on a Novel Degeneration Transistor-Ladder
Résumé:
A programmable-gain amplifier with low power consumption is presented. The programmable gain function is achieved by varying the effective transconductance ratios of input and output stages, which is realized through innovative binary-weighted and triode-region transistor ladder. The proposed technique effectively overcomes the problems associated with the implementation of resistors ladder in these types of structures. The operational principle of this unique structure is discussed, its most important formulas are derived, and its outstanding performance is verified by post-layout simulations in TSMC 0.18- $mu$ m N-well CMOS fabrication process. Owing to its unique construction, the proposed circuit combines the ever interesting constant bandwidth, linear-in-decibel, and fine-step programmable gain range merits all in a simple and low power structure. The core of proposed structure draws only 36.5 $mu$ W from 1.8-V power supply. The circuit is capable of delivering a wide programmable range of about 37 dB and operating at frequencies up to 20 MHz. To approve the robustness of the structure, full process, voltage, and temperature variation analysis of the circuit is investigated through corner case and Monte Carlo simulations. Monte Carlo simulations show standard deviation values of less than 0.21 $mu$ W and 0.5 dB in power consumption and voltage gain, respectively. These results indicate that the proposed structure would lend itself well for use in applications that demand high ratios of frequency over power consumption.
Auteurs: Hassan Faraji Baghtash;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 01.-2018, volume: 65, issue:1, pages: 36 - 40
Editeur: IEEE
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» A 40-Gb/s 4-Vpp Differential Modulator Driver in 90-nm CMOS
Résumé:
In this letter, a 40-Gb/s optical modulator driver in 90-nm CMOS technology is presented. The design is based on the distributed amplifier (DA) topology with the proposed modified cascode stage to obtain high gain and large bandwidth, while also capable of protecting the MOS transistor under large output voltage swing. The modified cascode stage DA with enhanced high-voltage driving capability can reach an operating data rate up to 40 Gb/s with an differential output voltage swing of 4 Vpp (~3-V eye amplitude), which can be used for driving 50- $Omega $ silicon modulators.
Auteurs: Yan-Feng Li;Po-Wei Chiu;Ke Li;David J. Thomson;Graham T. Reed;Shawn S. H. Hsu;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 73 - 75
Editeur: IEEE
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» A 42-Gb/s VCSEL Driver Suitable for Burst Mode Operation in 14-nm Bulk CMOS
Résumé:
In this letter, the design and measurement results of a high-swing 42-Gb/s vertical-cavity surface-emitting laser (VCSEL) driver with an optical modulation amplitude of 1.4 dB is presented. To keep the power dissipation low, no equalizer was employed at the highest rate. At the output stage circuit, a series-shunt peaking technique is used, and it is optimized to lower the group-delay variation at the laser input. The transmitter circuitry can be disabled when there is no data transmission to save half of the power required for the full-rate functionality. Then, it can be enabled in less than 10 ns to full rate operation. The chip is fabricated in a 14-nm bulk CMOS technology and bonded to a common-cathode 20-GHz VCSEL. Optical measurements show that the data transmission up to a data rate of 42 Gb/s with bit error rate better than 10−12 was possible. The total power dissipation, including the one of the VCSEL, is 81.5 mW, which provides a power efficiency of 1.94 pJ/b. To the best of our knowledge, this is the fastest VCSEL driver in any CMOS process suitable for burst mode operation.
Auteurs: Mahdi Khafaji;Jan Pliva;Ronny Henker;Frank Ellinger;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 01.-2018, volume: 30, issue:1, pages: 23 - 26
Editeur: IEEE
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» A 512-Gb 3-b/Cell 64-Stacked WL 3-D-NAND Flash Memory
Résumé:
A 64-word-line-stacked 512-Gb 3-b/cell 3-D NAND flash memory is presented. After briefly examining the challenges that occur to a stack, several technologies are suggested to resolve the issues. For performance enhancement, a novel program method hiding two-page data loading time is presented. This paper also discusses an electrical annealing improving reliability characteristic by removing holes in shallow traps. In addition, a valley tracking read for reducing timing overhead at a read retry is introduced by fast finding optimal read levels. Finally, a high-speed self-test mode for IO operation is presented. The chip, designed with the fourth generation of V-NAND technology, achieved an areal density of 3.98 Gb/mm2 and operated up to 1 Gb/s at 1.2 V.
Auteurs: Chulbum Kim;Doo-Hyun Kim;Woopyo Jeong;Hyun-Jin Kim;Il Han Park;Hyun-Wook Park;JongHoon Lee;JiYoon Park;Yang-Lo Ahn;Ji Young Lee;Seung-Bum Kim;Hyunjun Yoon;Jae Doeg Yu;Nayoung Choi;NaHyun Kim;Hwajun Jang;JongHoon Park;Seunghwan Song;YongHa Park;Jinbae
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 124 - 133
Editeur: IEEE
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» A Broadband Dual Circularly Polarized Conical Four-Arm Sinuous Antenna
Résumé:
A novel wideband four-arm sinuous antenna with dual circular polarizations (CPs) and unidirectional radiation is proposed. Different from the conventional designs, this sinuous antenna is realized in a conical form and no ground plane or absorptive cavity is required to obtain unidirectional radiation. The beamforming network for dual circularly polarized operations consists of a wideband quadrature coupler and two wideband baluns, and an auxiliary feeding patch is introduced to facilitate the connection between baluns and sinuous arms. The design of baluns and coupler is inspired from the printed exponentially tapered microstrip balun and broadside-coupled microstrip coupler, respectively. The dynamic differential evolution algorithm is employed to optimize the geometry of coupler for optimal performance. For both polarizations, the presented antenna has wide impedance bandwidth, good axial ratio, moderate realized gain, and front-to-back ratio within 2–5 GHz. An antenna prototype is fabricated and tested. The agreement between simulation and measurement results validates the proposed antenna framework. The demonstrated antenna has advantages of wide bandwidth, dual CPs, unidirectional radiation, lightweight, and low cost, and is promising for applications in wireless systems.
Auteurs: Shufeng Zheng;Steven Gao;Yingzeng Yin;Qi Luo;Xiaodong Yang;Wei Hu;Xueshi Ren;Fan Qin;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 01.-2018, volume: 66, issue:1, pages: 71 - 80
Editeur: IEEE
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» A Cascaded Part-Based System for Fine-Grained Vehicle Classification
Résumé:
Vehicle make and model recognition (VMMR) has become an important part of intelligent transportation systems. VMMR can be useful when license plate recognition is not feasible or fake number plates are used. VMMR is a hard, fine-grained classification problem, due to the large number of classes, substantial inner-class, and small inter-class distance. A novel cascaded part-based system has been proposed in this paper for VMMR. This system uses latent support vector machine formulation for automatically finding the discriminative parts of each vehicle category. At the same time, it learns a part-based model for each category. Our approach employs a new training procedure, a novel greedy parts localization, and a practical multi-class data mining algorithm. In order to speed up the system processing time, a novel cascading scheme has been proposed. This cascading scheme applies classifiers to the input image in a sequential manner, based on the two proposed criteria: confidence and frequency. The cascaded system can run up to 80% faster with analogous accuracy in comparison with the non-cascaded system. The extensive experiments on our data set and the CompCars data set indicate the outstanding performance of our approach. The proposed approach achieves an average accuracy of 97.01% on our challenging data set and an average accuracy of 95.55% on CompCars data set.
Auteurs: Mohsen Biglari;Ali Soleimani;Hamid Hassanpour;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 01.-2018, volume: 19, issue:1, pages: 273 - 283
Editeur: IEEE
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» A Case Study of Voltage Transformer Failures: Solution Implementation in a Modern Data Center
Résumé:
While preparing a modern data center for startup, the commissioning process involved primary circuit switching that resulted in two voltage transformer (VT) failures. As a result, we conducted a comprehensive investigation of the VT failures. As the investigation proceeded, VT ferroresonance on circuit opening and high-frequency switching transients on closing emerged as possible root causes of the failures. After incorporating extensive transient simulations and three rounds of field transient measurements, we designed and implemented a complete solution that included the sizing of snubbers to overcome excessive switching transients and the development of a saturable reactor to protect VTs against the effects of ferroresonance. This article describes the root causes, simulations, field measurements, recommended solutions, and solution implementation for this event. The correlation between field measurements and simulation results shows the effectiveness of modeling the implemented solutions.
Auteurs: Tamer Abdelazim Mellik;Thomas J. Dionise;Robert Yanniello;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 01.-2018, volume: 24, issue:1, pages: 98 - 109
Editeur: IEEE
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» A Center-of-Gravity-Based Approach to Estimate Slow Power and Frequency Variations
Résumé:
A novel approach based on the notion of center-of-gravity (COG) dynamics in mechanics is used to estimate local and global power system's frequency behavior. In this framework, the power system dynamic behavior is represented by an equivalent model in which the geographical areas interact with the COG through fictitious interconnectors from which the inherent dynamics of power frequency transients is explained using fundamental physics principles. The relationship between the frequency of the COG and the motion of local centers of angle is determined and expressions to compute local frequency deviations following major disturbances are derived. Detailed simulation results on three test power systems are used to demonstrate the accuracy and flexibility of the proposed method under both, N-1 and N-2 contingencies.
Auteurs: Hêmin Golpîra;Arturo Román Messina;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 1026 - 1035
Editeur: IEEE
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» A Chain Method for Preconditioned Iterative Linear Solvers for Power System Matrices
Résumé:
Many power systems applications such as power flow and short-circuit analysis require very large sparse matrix computations. With the increase in reliance on our electric infrastructure, power systems are continually growing in size, creating greater computational complexity in solving these large linear systems within reasonable time. For sparse matrix applications, it is desirable to have an algorithm with low runtime complexity in terms of the number of nonzeros in the matrix. There have been several recent advances in computational methods in other fields that, if applied to power system, could make real-time dynamic simulation a reality. Much work has been done for specific types of these problems where the system is symmetric and diagonally dominant, similar to the form of power system matrices. This paper details an expansion on the current work in fast linear solvers to develop power system specific methods that show potential for accurate solutions in $O(m log ^2 n)$ run times, where $n$ represents the number of nodes and $m$ represents the number of nonzeros in the power system matrix. This paper presents the simulation validation of a recently developed recursively solved iterative chain method for sparse matrices using a low stretch spanning tree preconditioner.
Auteurs: Lisa L. Grant;Mariesa L. Crow;Maggie X. Cheng;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 166 - 173
Editeur: IEEE
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» A Charge-Based Capacitance Model for Double-Gate Tunnel FETs With Closed-Form Solution
Résumé:
Based on an analytical surface potential and a simple mathematical approximation for the source depletion width, a physics-based capacitance model with closed form for silicon double-gate tunnel field-effect transistors (TFETs) is developed. Good agreements between the proposed model and the numerical simulations have been achieved, which reveal that the tunneling carriers from source have negligible contribution to the channel charges and the gate capacitance can be almost acted as the gate–drain capacitance, which is quite different from that of MOSFETs. This model without involving any iterative process is more SPICE friendly for circuit simulations compared with the table-lookup approach and would be helpful for developing the transient performance of TFET-based circuits.
Auteurs: Bin Lu;Hongliang Lu;Yuming Zhang;Yimen Zhang;Xiaoran Cui;Zhijun Lv;Shizheng Yang;Chen Liu;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 01.-2018, volume: 65, issue:1, pages: 299 - 307
Editeur: IEEE
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» A Chirp Scaling Algorithm for Forward-Looking Linear-Array SAR With Constant Acceleration
Résumé:
For forward-looking linear-array synthetic aperture radar (FLLA-SAR) with constant acceleration, the conventional hyperbolic range model is incorrect, and the range-dependent range cell migration (RCM) cannot be ignored any more. Hence, the traditional chirp scaling (CS) algorithm based on the hyperbolic range model also cannot be used. To overcome these problems, a modified range model for the FLLA-SAR which has taken the platform’s acceleration into consideration is proposed in this letter. Based on the model, an improved CS method is proposed for FLLA-SAR to eliminate the space-variant characteristic of the RCM. Simulation results are presented to validate the range model and the proposed method.
Auteurs: Yue Yuan;Si Chen;Shuning Zhang;Huichang Zhao;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 01.-2018, volume: 15, issue:1, pages: 88 - 91
Editeur: IEEE
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» A CMOS Medium Power Amplifier With Built-In Power Detector for Multistandard Dedicated Short-Range Communication Applications
Résumé:
This letter presents a 5.8-GHz medium power amplifier (PA) using 0.18- $mu text{m}$ CMOS technology with a built-in power detector for triple-mode operations, including amplitude-shift keying (ASK), frequency-shift keying (FSK), $pi $ /4-quadrature-phase shift keying, and multilevel complex modulations, for multistandard dedicated short-range communication applications. For ASK/FSK operations, the PA can work in nonlinear regions owing to the constant envelope feature of input signals that improve the power added efficiency, by which ASK modulation is achieved by modulating the bias of the PA output stage. The measured results show more than 10-dBm output power for all mode operations, with a chip area of $0.92 times 0.75$ mm2.
Auteurs: Chien-Chang Huang;Chia-Kai Chen;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 58 - 60
Editeur: IEEE
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» A Coherent Receiver Based on SIM for Quantum Communication
Résumé:
In this letter, we propose theoretically a coherent receiver based on solid-state impact-ionization multiplier (SIM) for quantum communication. In the newly proposed coherent receiver, the balanced photodetector (BPD) is used as a current source connected to the SIM. The signal from the BPD is fed into the SIM, where it is amplified through a desirable avalanche process, which is similar to the avalanche photodiodes, and can then be fed into a transimpedance amplifier for voltage readout. Compared with the conventional coherent receiver with only coherent gain, the signal gain of the proposed coherent receiver consists of two parts, the coherent gain produced by the local oscillator (LO) and the avalanche gain produced by the SIM, so the LO power can be decreased to avoid the saturation of the BPD without sacrificing the signal gain. What is more, the proposed receiver can operate at a higher bandwidth by optimizing the structure of the coherent receiving end and redesigning the geometry of the SIM.
Auteurs: Ke Wen;Yanli Zhao;Junjie Tu;Jing Xu;Yuan Li;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 01.-2018, volume: 30, issue:1, pages: 27 - 30
Editeur: IEEE
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» A Combined Optimization-Theoretic and Side- Channel Approach for Attacking Strong Physical Unclonable Functions
Résumé:
The promise of strong physical unclonable functions (PUF) is to utilize the manufacturing variations of circuit elements to produce an independent and unpredictable response to any input challenge vector. Attacks on PUFs that predict the responses to input challenge vectors offer an interesting research problem. An attacking approach based on the optimization theory and side-channel information is proposed where we estimate the manufacturing variations of the circuit elements and predict the PUF’s responses to challenge vectors whose actual responses are not known. We apply this attacking approach on some popular PUF designs, including the Arbiter PUFs, the Memristor Crossbar PUFs, and the XOR Arbiter PUFs. Simulations show a substantial reduction in attack complexity compared with previously proposed machine-learning (ML)-based attacks: we achieve an average reduction of 66% in attack time compared with the ML approach. Despite some overhead, our approach is also applicable when the PUF responses are noisy.
Auteurs: Yuntao Liu;Yang Xie;Chongxi Bao;Ankur Srivastava;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 01.-2018, volume: 26, issue:1, pages: 73 - 81
Editeur: IEEE
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» A Communication Channel With Random Battery Recharges
Résumé:
Motivated by the recent emergence of energy harvesting and wirelessly powered transceivers, we study communication over a memoryless channel with a transmitter, whose battery is recharged at random or deterministic times known to the receiver. We characterize the capacity of this channel as the limit of an $n$ -letter maximum mutual information rate under various assumptions: causal and noncausal transmitter knowledge of the battery recharges, with or without feedback from the receiver to the transmitter. While the resultant $n$ -letter capacity expressions are not computable in the general case, we demonstrate their usefulness by focusing on two important special cases, namely, the binary erasure channel (BEC) and the additive white Gaussian noise (AWGN) channel, where they lead to some interesting, and somewhat surprising, insights. By focusing on the BEC, we show that output feedback can strictly increase the capacity of this channel, even though the channel is memoryless and the battery recharging process is independent over time. Interestingly, this provides a counter example to an old claim by Shannon stated without proof in his 1956 paper. On the other hand, by focusing on the AWGN channel, we are able to show that the capacity with noncausal knowledge of the battery recharging times at the transmitter is strictly larger than that with causal knowledge, even though the battery recharging process is independent over time and known to the receiver. The $n$ -letter expressions can also be used to derive explicit upper and lower bounds on capacity. In particular, we derive simple upper and lower bounds on the capacity of the AWGN channel with random battery recharges, which are within 1.05 b/s/Hz of each other for all parameter values.
Auteurs: Dor Shaviv;Ayfer Özgür;Haim H. Permuter;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 01.-2018, volume: 64, issue:1, pages: 38 - 56
Editeur: IEEE
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» A Compact and Low-Profile MIMO Antenna Using a Miniature Circular High-Impedance Surface for Wearable Applications
Résumé:
A new miniature circular high-impedance surface (HIS) is used to design a compact and low-profile multi-in multi-out (MIMO) antenna for wearable applications. The antenna is designed to operate from 2.4 to 2.49 GHz for wireless local area network application. By employing a pair of degenerated characteristic modes of a circular loop antenna, the MIMO antenna can achieve a good port-to-port isolation (>15 dB) without increasing its geometric size. A four-element HIS is chosen to match the antenna profile, and a 2 dBi antenna gain improvement is observed. The design was optimized considering the effect of packaging and then a prototype with the optimal parameters was fabricated and tested. Measurement results are in good agreement with simulation results. Furthermore, the loading effect due to lossy human tissue is also considered and the results show that the antenna has a robust performance against the human phantom and a low specific absorption rate can also be obtained.
Auteurs: Dingliang Wen;Yang Hao;Max O. Munoz;Hanyang Wang;Hai Zhou;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 01.-2018, volume: 66, issue:1, pages: 96 - 104
Editeur: IEEE
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» A Compact Microstrip T-Type Switch for Narrowband Applications
Résumé:
This paper presents a compact T-type switch that involves three different operational states providing high flexibility in signal routing. Two of the states are between adjacent ports, while the other is a crossover state. T-type switches are mainly used as building blocks of redundancy matrices for satellite communications systems, although mobile applications also take advantage of switching devices. The proposed structure uses p-i-n diodes located in specific points to control each state with a specific bias dc voltage, creating open and short circuits. The symmetry of the structure allows even–odd mode analysis in order to obtain the design equations. To validate the concept, a compact microstrip T-type switch is fabricated and measured. The resulting device shows a good performance in terms of transmission and isolation for each state, in agreement with the simulations. The switch exhibits a band-pass response for the crossover state, while low-pass and high-pass responses result for the other two states.
Auteurs: Alfred Gimenez;Jordi Verdú;Eden Corrales;Pedro de Paco Sánchez;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 01.-2018, volume: 66, issue:1, pages: 170 - 176
Editeur: IEEE
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» A Compact Single-Stage Wide-Band Balun: A 4:1 Wide-Band Transmission-Line Balun Based on a Combination of Two Different Ferrite Cores
Résumé:
This article presents the design procedure and measurement results for a 4:1 wide-band transmission-line balun based on a combination of two different ferrite cores. The balun ranked first at the Student Design Competition for "Wide-Band Baluns" that took place during the IEEE Microwave Theory and Techniques Society (MTT-S) 2017 International Microwave Symposium (IMS2017) in Honolulu, Hawaii, last May and sponsored by Technical Coordinating Committee MTT-17. Each competition team was required to bring a balun designed by the students. The team that achieved the widest measured bandwidth, from 300 kHz to 1 GHz under the competition rules, was named the winner.
Auteurs: Taewan Kim;Hwiseob Lee;Wonseob Lim;Sungjae Oh;Hansik Oh;Keum Cheol Hwang;Kang-Yoon Lee;Cheon-seok Park;Youngoo Yang;
Apparue dans: IEEE Microwave Magazine
Date publication: 01.-2018, volume: 19, issue:1, pages: 78 - 83
Editeur: IEEE
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» A Compact Tunable Directional Coupler with Continuously Tuned Differential Phase
Résumé:
A tunable directional coupler with outputs that have continuously tuned phase difference and constant magnitude is presented. The initial design is based on a 3-dB branch-line coupler with two arms having variable electrical lengths. To realize the variable-length lines, a novel concept of tunable phase shifting unit, which includes a pair of inductor-varactor loaded coupled lines, is proposed. By controlling the shifting phase of the two arms, the differential phase (i.e., the phase difference between the two output ports) can be tuned continuously. Explicit relation between the objective differential phase of the device and the required shifting phase of those units is analyzed and explained. To validate the design, a prototype is built, simulated, and tested. The experimental and predicted results agree well and show that the device can realize arbitrary and continuously tunable differential phase from 45° to 135°. The overall size of the design is only $0.18 lambda _{g} times 0.24 lambda _{g}$ , which is extremely compact compared with using a cascaded coupler-phase shifters and is thus suitable for miniaturized wireless systems.
Auteurs: He Zhu;Amin M. Abbosh;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 19 - 21
Editeur: IEEE
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» A Compact Ultra-Wideband Multibeam Antenna System
Résumé:
A compact UWB (6–18 GHz) multibeam antenna system is proposed. Design procedures comprising of ridged coaxial waveguide, radome with lens properties, and biconical antenna are presented. A novel UWB feed network consisting of a ridged coaxial waveguide with eight inputs has been designed and optimized to achieve minimum reflections as well as desired radiation pattern over the frequency range of operation. The radiating element is a biconical antenna, redesigned and optimized to meet the requirements for radiation characteristics. Another notable improvement made by our design is to employ a radome, which not only enhances the mechanical stability of the biconical antenna and protects the structure, but also it acts as a lens that improves the directivity of the radiating element. Extensive optimization procedures have been applied to all parts of the antenna system to achieve the desired performance. The whole system has been simulated using HFSS full-wave simulator. The measurement results of the fabricated system are in good agreement with simulations.
Auteurs: Ahmad Emadeddin;Mohammad Ali Salari;Mahdi Zoghi;Amin Darvazehban;Omid Manoochehri;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 01.-2018, volume: 66, issue:1, pages: 125 - 131
Editeur: IEEE
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» A Comparative Study on Hot-Carrier Injection in 5-Story Vertically Integrated Inversion-Mode and Junctionless-Mode Gate-All-Around MOSFETs
Résumé:
The hot-carrier degradation of the junctionless mode (JM) and the inversion mode (IM) of five-story vertically integrated gate-all-around (GAA) MOSFETs is investigated for the first time. It is found that the degradation of drain current induced by the hot-carrier injection (HCI) in the JM-FET is less than that in the IM-FET for the same dimensions and bias conditions, because of the bulk conduction mechanism of the JM-FET, which is in contrast to surface conduction of the IM-FET. The results are obtained using electrical measurements and numerical simulations. The analysis of how HCI affects the lifetime reliability of vertically integrated GAA MOSFETs is of great importance for ultimate scaling of the silicon transistor.
Auteurs: Seong-Yeon Kim;Byung-Hyun Lee;Jae Hur;Jun-Young Park;Seung-Bae Jeon;Seung-Wook Lee;Yang-Kyu Choi;
Apparue dans: IEEE Electron Device Letters
Date publication: 01.-2018, volume: 39, issue:1, pages: 4 - 7
Editeur: IEEE
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» A Comparison of Electroluminescence Spectra From Plan View and Cross-Sectioned AlGaN/GaN Devices
Résumé:
We report on a comparison of electroluminescence (EL) spectra measured in plan view versus on a cross-sectioned face of the same AlGaN/GaN device for the first time. Because EL emission can be more intense under optically opaque metal structures, a difference was expected. We observed and quantified the difference in EL intensity and the extracted electron temperature. We discuss the effect on the rate of proposed channel hot-carrier degradation. Device simulations were used to gain insight on the expected spatial distribution of hot electrons within the channel. Last, spectra acquired on the cross-sectioned face were found to be free of interference artifacts common in plan view that could complicate the interpretation of the spectral data.
Auteurs: Albert M. Hilton;Adam D. Cahill;Eric R. Heller;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 01.-2018, volume: 65, issue:1, pages: 59 - 63
Editeur: IEEE
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» A Computationally Efficient Reconfigurable Constant Multiplication Architecture Based on CSD Decoded Vertical–Horizontal Common Sub-Expression Elimination Algorithm
Résumé:
This paper introduces a computationally efficient hardware architecture for reconfigurable multiple constant multiplication block, which functions according to the canonical signed digit (CSD)-based vertical and horizontal common sub-expression elimination (VHCSE) algorithm. In the proposed architecture, the CSD decoded coefficient along with 4-b common sub-expressions (CSs) in the vertical direction and 4- and 8-b CSs in the horizontal direction reduces the required number of full adder cells and the adder depths. This technique helps in reducing area consumption by decreasing the number of coefficient multiplier adders by 59% than that of the binary VHCSE (VHBCSE) algorithm. This technique helps in reducing the average switching activity of the adder blocks used in each coefficient multiplier block by 26.1%, 25.6%, and 21.3%, while compared with those of the 2- and 3-b binary CS elimination (BCSE) and VHBCSE algorithms, respectively. For different orders of filter, the proposed one delivers 57.5% and 61.9% improvement in area-power product (APP) on an average compared with the VHBCSE and mixed integer programming algorithms, respectively. Experimental results of differently specified finite impulse response (FIR) filters ranging from 10 to 100 taps and the coefficients of 8, 12, and 16 b show the improvements of 42.8%, 53.6%, and 37%, respectively, in the average gate count and 51.8%, 43.5%, and 36.7% less propagation delay than those of earlier canonical double-based number representation method. Moreover, in the metric made of APP divided by throughput, the proposed technique experiences 63.7% improvement on an average over that of faithfully rounded truncated multiple constant multiplication/accumulation technique of - esigning constant multiplier and demonstrates its suitability for implementing efficient reconfigurable FIR filter.
Auteurs: Indranil Hatai;Indrajit Chakrabarti;Swapna Banerjee;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 01.-2018, volume: 65, issue:1, pages: 130 - 140
Editeur: IEEE
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» A Cooperative Clustering Protocol With Duty Cycling for Energy Harvesting Enabled Wireless Sensor Networks
Résumé:
This paper proposes a cooperative clustering protocol based on the low energy adaptive clustering hierarchy approach to enhance the longevity of energy harvesting-based wireless sensor networks (EH-WSN). In the proposed protocol, to ensure that any energy consumption associated with the role of the cluster head (CH) is shared between the nodes, the CH role is alternated between the nodes using duty cycling as a function of their individual energy harvesting capabilities. Furthermore, to maintain an energy neutral operation when not acting as a CH, the nodes adopt a data transmission duty cycle and any excess energy is invested in relaying other nodes’ packets. To optimize the relaying performance, a novel cross-layer cooperative TDMA scheme is also presented. The optimal number of clusters in an EH-WSN is analyzed in terms of energy consumption, latency, and bandwidth utilization. Simulations, performed using GreenCastalia, demonstrate tangible performance enhancements in adopting the proposed protocol over benchmark schemes in terms of throughput and lifetime, particularly under highly constrained energy conditions.
Auteurs: Mohammed S. Bahbahani;Emad Alsusa;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 01.-2018, volume: 17, issue:1, pages: 101 - 111
Editeur: IEEE
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» A Coordinated Dispatch Model for Distribution Network Considering PV Ramp
Résumé:
The ramp events of photovoltaic (PV) generation will cause severe voltage variations in a distribution network. To address this issue, a two-stage robust optimization based intra-hour dispatch model is proposed for the coordination of the on-load tap changer and smart PV systems. Hence, the distribution network security can be ensured by adjusting substation voltage and controlling PV systems. Case study on 33-bus system verifies the effectiveness of the proposed model.
Auteurs: Jiayong Li;Zhao Xu;Jian Zhao;Can Wan;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 1107 - 1109
Editeur: IEEE
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» A DC-75-GHz Bandwidth and 54 $text {dB}Omega $ Gain TIA With 10.9 pA/ $sqrt {mathrm {Hz}} $ in 130-nm SiGe:C BiCMOS
Résumé:
A broadband low-noise amplifier with transimpedance (TI) feedback implemented in a 130-nm SiGe:C BiCMOS technology with $f_{T}$ of 300 GHz is presented. The circuit provides 22-dB gain and 75-GHz bandwidth while dissipating only 95 mW of power, achieving a gain bandwidth against dc power efficiency (GBW/ $P_{mathrm {dc}}$ ) of 9.9 GHz/mW. Measured noise figure (NF) is 4 dB until 26.5 GHz, rising up to 6 dB at 70 GHz based on simulation. Ultrahigh data rate support is demonstrated with clear eye diagrams up to 100 Gb/s. Intended as a TI front end for optical receivers, the amplifier features 54- $text {dB}Omega $ TI gain with only 10.9 pA/ $sqrt {mathrm {Hz}}$ averaged input-referred current noise density. Measured input-referred 1-dB compression point at 1 GHz occurs at −20 dBm input power. To the best of the authors’ knowledge, the proposed amplifier exhibits the highest GBW/ $P_{mathrm {dc}}$ with the lowest NF reported to date, toward the next generation 400 Gb/s Ethernet.
Auteurs: Iria García López;Pedro Rito;A. Awny;Minsu Ko;Dietmar Kissinger;A. Cagri Ulusoy;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 61 - 63
Editeur: IEEE
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» A Delay Relaxed RLS-DCD Algorithm for Real-Time Implementation
Résumé:
The recursive least squares algorithm (RLS) using dichotomous coordinate descent (DCD) iterations, namely, RLS-DCD, is regarded to be well suited for hardware implementation because of its small computational complexity compared to the classical RLS algorithm. While this is true, yet another important aspect that ultimately determines its applicability for real-time applications with high sample rates, is its iteration bound. In this brief, we discuss this issue and propose a modified RLS-DCD algorithm based on delay relaxation whose iteration bound can be reduced arbitrarily. The degradation in convergence speed is shown to be tolerable, which results in still much faster convergence compared to the normalized least mean square algorithm.
Auteurs: Geonu Kim;Hyuk Lee;Jinjoo Chung;Jungwoo Lee;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 01.-2018, volume: 65, issue:1, pages: 61 - 65
Editeur: IEEE
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» A Delayed-Excitation Data Acquisition Method for High-Frequency Ultrasound Imaging
Résumé:
High-frequency ultrasound imaging (at >20 MHz) has gained widespread attention due to its high spatial resolution being useful for basic cardiovascular and cancer research involving small animals. The sampling rate of the analog-to-digital converter in a high-frequency ultrasound system usually needs to be higher than 120 MHz in order to satisfy the Nyquist sampling-rate requirement. However, the sampling rate is typically within the range of 40–60 MHz in a traditional ultrasound system, and so we propose a delayed-excitation method for performing high-frequency ultrasound imaging with a traditional data acquisition scheme. In this method, the transmitted pulse is delayed by a certain time period so that the ultrasound echo data are aligned into high-sampling-rate slots. Wire and tissue-mimicking phantoms were imaged to evaluate the performance of the proposed method, whereas a porcine small-intestine specimen and an excised rabbit eyeball were used for in vitro imaging evaluations. The test results demonstrate that the proposed method allows high-frequency ultrasound imaging to be implemented using a traditional ultrasound sampling system.
Auteurs: Weibao Qiu;Jingjing Xia;Yulong Shi;Peitian Mu;Xingying Wang;Mengdi Gao;Congzhi Wang;Yang Xiao;Ge Yang;Jihong Liu;Lei Sun;Hairong Zheng;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 01.-2018, volume: 65, issue:1, pages: 15 - 20
Editeur: IEEE
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» A Design Space Exploration Methodology for Parameter Optimization in Multicore Processors
Résumé:
The need for application-specific design of multicore/manycore processing platforms is evident with computing systems finding use in diverse application domains. In order to tailor multicore/manycore processors for application specific requirements, a multitude of processor design parameters have to be tuned accordingly which involves rigorous and extensive design space exploration over large search spaces. In this paper, we propose an efficient methodology for design space exploration. We evaluate our methodology over two search spaces small and large, using a cycle-accurate simulator (ESESC) and a standard set of PARSEC and SPLASH-2 benchmarks. For the smaller design space, we compare results obtained from our design space exploration methodology with results obtained from fully exhaustive search. The results show that solution quality obtained from our methodology are within 1.35 - 3.69 percent of the results obtained from fully exhaustive search while only exploring 2.74 - 3 percent of the design space. For larger design space, we compare solution quality of different results obtained by varying the number of tunable processor design parameters included in the exhaustive search phase of our methodology. The results show that including more number of tunable parameters in the exhaustive search phase of our methodology greatly improves solution quality.
Auteurs: Prasanna Kansakar;Arslan Munir;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 01.-2018, volume: 29, issue:1, pages: 2 - 15
Editeur: IEEE
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» A Deterministic Method to Identify Multiple Local Extrema for the AC Optimal Power Flow Problem
Résumé:
This paper presents a deterministic approach to compute multiple local extrema for AC Optimal Power Flow (ACOPF) problems. An elliptical representation of the sphere-confined Fritz John conditions is constructed from a quadratic formulation of the ACOPF problem. Application of a branch tracing method to the elliptical formulation enables the calculation of multiple solutions. Further, a monotone search strategy enhances the computational efficiency of finding multiple local solutions with improved objective values. The proposed approach is first illustrated using two small examples with known feasible spaces. Then, four additional local solutions to a 39-bus system are found using the proposed approach.
Auteurs: Dan Wu;Daniel K. Molzahn;Bernard C. Lesieutre;Krishnamurthy Dvijotham;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 654 - 668
Editeur: IEEE
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» A Developer Centered Bug Prediction Model
Résumé:
Several techniques have been proposed to accurately predict software defects. These techniques generally exploit characteristics of the code artefacts (e.g., size, complexity, etc.) and/or of the process adopted during their development and maintenance (e.g., the number of developers working on a component) to spot out components likely containing bugs. While these bug prediction models achieve good levels of accuracy, they mostly ignore the major role played by human-related factors in the introduction of bugs. Previous studies have demonstrated that focused developers are less prone to introduce defects than non-focused developers. According to this observation, software components changed by focused developers should also be less error prone than components changed by less focused developers. We capture this observation by measuring the scattering of changes performed by developers working on a component and use this information to build a bug prediction model. Such a model has been evaluated on 26 systems and compared with four competitive techniques. The achieved results show the superiority of our model, and its high complementarity with respect to predictors commonly used in the literature. Based on this result, we also show the results of a “hybrid” prediction model combining our predictors with the existing ones.
Auteurs: Dario Di Nucci;Fabio Palomba;Giuseppe De Rosa;Gabriele Bavota;Rocco Oliveto;Andrea De Lucia;
Apparue dans: IEEE Transactions on Software Engineering
Date publication: 01.-2018, volume: 44, issue:1, pages: 5 - 24
Editeur: IEEE
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» A Differential Output Interfacing ASIC for Integrated Capacitive Sensors
Résumé:
In this paper, we have proposed an input interfacing scheme with differential output for integrated capacitive sensor applications. In the proposed scheme, the front-end interfacing is based on switched capacitor charge amplifier configuration using a fully differential operational transconductance amplifier and one differential capacitive sensor arrangement which provides differential output with minimum number of circuit components. In the back end, a sigma–delta ( $Sigma Delta $ ) modulator is integrated for modulated digital output. The signal conditioning circuit also includes gain programmability by selecting proper feedback capacitor and mismatch cancellation between the sensing capacitors through on-chip capacitors array. The complete application specific integrated circuit (ASIC) is designed and fabricated in United Microelectronics Corporation (UMC) $0.18-mu text{m}$ CMOS process technology. The fabricated ASIC is then integrated with a silicon-on-insulator microelectromechnical systems capacitive accelerometer to test and characterize the performance of the proposed scheme. The measured result shows that the sensitivity of the proposed circuit can be varied from 200 to 900 mV/g by changing the feedback capacitor. The integrated system is also tested with electrostatic actuation as well as with a vibrating shaker and the measurement results are presented.
Auteurs: Sougata Kumar Kar;Procheta Chatterjee;Banibrata Mukherjee;Kenkere Balashantha Murthy Mruthyunjaya Swamy;Siddhartha Sen;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 01.-2018, volume: 67, issue:1, pages: 196 - 203
Editeur: IEEE
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» A Differential Quantizer-Based Error Feedback Modulator for Analog-to-Digital Converters
Résumé:
A differential quantizer-based error feedback modulator intended for digitizing analog signals and its comparison to the traditional interpolative sigma delta analog-to-digital conversion is presented in this brief. The differential quantizer-based error feedback modulator also falls under the class of noise-shaping data converters. This newly introduced technique replaces the integrator with a differential quantizer to achieve noise-shaping characteristics. Thus, integrator associated non-idealities, loop-stability issues, and optimization of the integrator scaling coefficients is no more a concern. Differential quantizer-based error feedback modulator technique can perform well in high-precision and low-power applications. Behavioral-level simulation results demonstrate the mathematical equivalence of the differential quantizer based error feedback modulator technique with interpolative sigma delta modulator technique and confirms its novelty, theoretical stability, and scalability to higher order. The circuit level feasibility and effectiveness of the proposed architecture is verified in a 45-nm CMOS process using a 1-V supply with a power consumption of 0.22 and 0.5 mW for the first and second order modulators, respectively.
Auteurs: A. V. Jos Prakash;Babita R. Jose;Jimson Mathew;Bijoy A. Jose;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 01.-2018, volume: 65, issue:1, pages: 21 - 25
Editeur: IEEE
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» A Digitally Controlled Fully Integrated Voltage Regulator With On-Die Solenoid Inductor With Planar Magnetic Core in 14-nm Tri-Gate CMOS
Résumé:
A fully integrated digitally controlled two-phase buck voltage regulator (VR) with on-die solenoid inductors with a planar magnetic core is demonstrated in 14-nm tri-gate CMOS for fine-grained power delivery/management domains of high power density in system-on-chips while enabling ultra-thin (z-height) packages. The VR achieves 1-A/mm2 power density for 400-mA load current with a measured peak efficiency of 84% at 100-MHz switching frequency including a digital PWM with >9 bits (8 ps) of resolution.
Auteurs: Harish K. Krishnamurthy;Vaibhav Vaidya;Pavan Kumar;Rinkle Jain;Sheldon Weng;Stephen T. Kim;George E. Matthew;Nachiket Desai;Xiaosen Liu;Krishnan Ravichandran;James W. Tschanz;Vivek De;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 8 - 19
Editeur: IEEE
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» A Direct Algorithm for Optimization Problems With the Huber Penalty
Résumé:
We present a direct (noniterative) algorithm for 1-D quadratic data fitting with neighboring intensity differences penalized by the Huber function. Applications of such an algorithm include 1-D processing of medical signals, such as smoothing of tissue time concentration curves in kinetic data analysis or sinogram preprocessing, and using it as a subproblem solver for 2-D or 3-D image restoration and reconstruction. dynamic programming was used to develop the direct algorithm. The problem was reformulated as a sequence of univariate optimization problems, for ${k} =textsf {1}, ldots , {N}$ , where ${N}$ is the number of data points. The solution to the univariate problem at index ${k}$ is parameterized by the solution at ${k}+textsf {1}$ , except at ${k}={N}$ . Solving the univariate optimization problem at ${k}={N}$ yields the solution to each problem in the sequence using back-tracking. Computational issues and memory cost are discussed in detail. Two numerical studies, tissue concentration curve smoothing and sinogram preprocessing for image reconstruction, are used to validate the direct algorithm and illustrate its practical applications. In the example of 1-D curve smoothing, the efficiency of the direct algorithm is compared with four iterative methods: the iterative coordinate descent, Nesterov’s accelerated gradient descent algorithm, FISTA, and an off-the-shelf second order method. The first two methods were applied to the primal problem, the others to the dual problem. The comparisons show that the direct - lgorithm outperforms all other methods by a significant factor, which rapidly grows with the curvature of the Huber function. The second example, sinogram preprocessing, showed that robustness and speed of the direct algorithm are maintained over a wide range of signal variations, and that noise and streaking artifacts could be reduced with almost no increase in computation time. We also outline how the proposed 1-D solver can be used for imaging applications.
Auteurs: Jingyan Xu;Frédéric Noo;Benjamin M. W. Tsui;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 01.-2018, volume: 37, issue:1, pages: 162 - 172
Editeur: IEEE
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» A Distributed Raman Amplifier Based on the Backward-Pumped Random Fiber Laser
Résumé:
For the first time, a backward-pumped random distributed feedback fiber laser is applied to the conventional distributed Raman amplification (DRA). A new asymmetric DRA scheme for improving the signal power variation (SPV) performance was achieved. The scheme was studied numerically and was shown to effectively reduce the SPV of all signals to less than 1.2 dB, whilst maintaining a flat ON–OFF gain over 40 nm bandwidth for a 61.5 km fiber span. Moreover, the nonlinear Fourier transform technique, which is utilized to deal with the nonlinear noise, could be realized on the proposed scheme with such a low SPV.
Auteurs: You Wang;Ying Wang;Wei Li;Qiguang Feng;Qiang Zheng;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 01.-2018, volume: 30, issue:2, pages: 173 - 176
Editeur: IEEE
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» A Distributed-Deflection Sensor With a Built-In Probe for Conformal Mechanical Measurements of Costal Cartilage at Its Exterior Surface
Résumé:
In this paper, a distributed-deflection sensor with a built-in probe is proposed to achieve conformal mechanical measurements of costal cartilage (CC) at its exterior surface. The sensor entails a rectangular sensing-plate integrated with a $5 times 1$ transducer array with 0.75 mm spatial resolution underneath and a built-in probe of $0.5~{mathrm{ mm}}times 5~{mathrm{ mm}}times 3~{mathrm{ mm}}$ above. By pressing the sensor against the exterior surface of a CC tissue with a pre-defined indentation depth pattern, the sensor conforms to the curved tissue surface via the built-in probe first, and then the mechanical properties of the tissue translate to the spatially distributed deflection in the sensor and register as resistance changes by the transducer array. One human Pectus Carinatum (PC) CC sample is measured using the sensor without a built-in probe, and two human PC samples are measured using the sensor with a built-in probe. The comparison in measured results among the three samples validates the capability of the sensor with a built-in probe for conformity to a curved tissue surface in measurements. Based on the recorded relation of average sensor deflection to indentation depth of the two samples measured using the sensor with a built-in probe, the tissue instant indentation modulus and normalized relaxation amount of the two samples are derived and found to vary significantly among the anterior/posterior surfaces and superior/inferior borders at the same position of each sample.
Auteurs: Jiayue Shen;Michael Stacey;Zhili Hao;
Apparue dans: IEEE Sensors Journal
Date publication: 01.-2018, volume: 18, issue:2, pages: 822 - 829
Editeur: IEEE
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» A Doherty Amplifier With Modified Load Modulation Scheme Based on Load–Pull Data
Résumé:
We present the design and development of a Ka-band Doherty power amplifier (DPA) that achieves high efficiency at power backoff (PBO) using a new load modulation scheme and a proposed load–pull-based design technique. Using the proposed technique, the device size of the peaking amplifier and the impedance of the quarter-wavelength ( $lambda $ /4) inverter are properly chosen to achieve high power-added efficiency (PAE) at a specific PBO level. The DPA is fabricated in a 0.15- $mu {text{m}}$ gallium arsenide pseudomorphic high-electron mobility transistor enhancement mode process and achieves a measured small signal gain of 10.5 dB, output power at 1-dB compression point ( $P_{1,{text{dB}}}$ ) of 27 dBm, and measured maximum PAE of 38%. The PAE at 6-dB PBO and 8-dB PBO are 32% and 28.5%, respectively. Furthermore, the PAE at 6-dB PBO maintains higher than 28.4% over a 1-GHz bandwidth from 29.25 to 30.25 GHz.
Auteurs: Duy P. Nguyen;Jeffery Curtis;Anh-Vu Pham;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 01.-2018, volume: 66, issue:1, pages: 227 - 236
Editeur: IEEE
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» A Dynamic Regrouping Based Dynamic Programming Approach for Unit Commitment of the Transmission-Constrained Multi-Site Combined Heat and Power System
Résumé:
Combined heat and power (CHP) systems offer additional advantage and flexibility for addressing power grid balance resulting from large-scale introduction of intermittent renewable energy sources (RES) in contrast to power-only systems. The dependence between heat and power production in the CHP plant can be utilized to adjust power production level to accommodate more RES. Furthermore, electricity can be transformed into heat by electric heater and heat pump to avoid starting up heat led CHP plants when RES production is abundant. This paper focuses on solving efficiently unit commitment of the interconnected multi-site CHP system without considering RES. A relaxed on/off state based dynamic programming applying sequential commitment scheme in conjunction with dynamic regrouping is used to coordinate heat and power production in each site (region) as well as power transmission across sites. Computational experiments for real-life daily scheduling demonstrate that our method generates solutions much more quickly than a standard high-performance optimizer (CPLEX) with comparable solution quality, and lays foundation for the future handling of uncertainties of intermittent RES.
Auteurs: Aiying Rong;Peter B. Luh;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 714 - 722
Editeur: IEEE
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» A Fast and Adaptive Method for Determining $K_{1}$ , $K_{2}$ , and $K_{3}$ in the Tensor Decomposition-Based Anomaly Detection Algorithm
Résumé:
In our previous work, a tensor decomposition-based anomaly detection algorithm has been proposed. However, determining $K_{1}$ , $K_{2}$ , and $K_{3}$ (i.e., the major principal component numbers along the three modes of hyperspectral data) has not been settled satisfactorily. In this letter, a fast and adaptive method for determining $K_{1}$ , $K_{2}$ , and $K_{3}$ is proposed. In the proposed method, the determination problem is converted into an optimization problem by constructing the energy function by maximizing the anomalous degree of the reconstructed anomaly data in both spectral and spatial domains. In order to reduce the computational complexity, a fast initialization strategy is introduced to initialize those parameters in the feature space directly. In addition, to avoid the problem of parameter selection, an adaptive strategy is utilized. Furthermore, $K_{1}$ and $K_{2}$ are considered to be independent, making the degree of freedom of the three parameters conform with the actual. Experiments with three hyperspectral data sets reveal that the proposed method works effectively.
Auteurs: Xing Zhang;Gongjian Wen;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 01.-2018, volume: 15, issue:1, pages: 3 - 7
Editeur: IEEE
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» A Fast Sensitivity Method for Determining Line Loss and Node Voltages in Active Distribution Network
Résumé:
A fast sensitivity method for determining line loss and node voltages in active distribution network is proposed. A quadratic sensitivity model of distributed generation (DG) output or load to Line Loss (QSLL) and a linear sensitivity model of DG output or load to node voltages (LSNV) are established based on one initial load flow calculation. Using these models, the variety of line loss and node voltages of distribution network can be directly determined with the variation of DG output or load demand. The proposed QSLL is more concise and accurate compared to the conventional linear sensitivity model. And the proposed LSNV are more concise than the conventional one.
Auteurs: Shouxiang Wang;Qi Liu;Xingquan Ji;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 1148 - 1150
Editeur: IEEE
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» A Finite Convergence Criterion for the Discounted Optimal Control of Stochastic Logical Networks
Résumé:
Stochastic logical networks (SLNs) are discrete-time stochastic dynamical systems with Boolean (or multivalued) logical state variables. The discounted infinite horizon optimal control problem for SLN is addressed in this paper. By resorting to the equivalent Markov decision process description, the infinite horizon optimization problem is presented in algebraic form. Then using the increasing-dimension technique, an improved finite convergence criterion, which can find the optimal stationary policy, is derived for value iteration approach. To demonstrate the theoretical value of this approach, it is applied to the optimization problems of the human–machine game and the p53-Mdm2 gene network.
Auteurs: Yuhu Wu;Tielong Shen;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 01.-2018, volume: 63, issue:1, pages: 262 - 268
Editeur: IEEE
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» A Five-Level MILP Model for Flexible Transmission Network Planning Under Uncertainty: A Min–Max Regret Approach
Résumé:
The benefits of new transmission investment significantly depend on deployment patterns of renewable electricity generation that are characterized by severe uncertainty. In this context, this paper presents a novel methodology to solve the transmission expansion planning problem under generation expansion uncertainty in a min–max regret fashion, when considering flexible network options and $n-1$ security criterion. To do so, we propose a five-level mixed integer linear programming (MILP) based model that comprises: (i) the optimal network investment plan (including phase shifters), (ii) the realization of generation expansion, (iii) the co-optimization of energy and reserves given transmission and generation expansions, (iv) the realization of system outages, and (v) the decision on optimal post-contingency corrective control. In order to solve the five-level model, we present a cutting plane algorithm that ultimately identifies the optimal min–max regret flexible transmission plan in a finite number of steps. The numerical studies carried out demonstrate: (a) the significant benefits associated with flexible network investment options to hedge transmission expansion plans against generation expansion uncertainty and system outages, (b) strategic planning-under-uncertainty uncovers the full benefit of flexible options which may remain undetected under deterministic, perfect information methods, and (c) the computational scalability of the proposed approach.
Auteurs: Alexandre Moreira;Goran Strbac;Rodrigo Moreno;Alexandre Street;Ioannis Konstantelos;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 486 - 501
Editeur: IEEE
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» A Fixed-Scale Pixelated MIMO Visible Light Communication System
Résumé:
A pixelated MIMO wireless optical communication system is introduced, which transmits a series of time-varying coded images that can be received and decoded by commercial digital cameras. The system exploits the bokeh effect to obtain fixed-scale images at all link distances by placing a convex lens in front of the transmitter array at its focal length and focusing the receiver at infinity. This spatial-angular mapping simplifies the receiver structure requiring no re-focusing as the receiver moves. As an additional benefit, this mapping can also be exploited to provide location information to the receiver. The channel model is measured and modeled and rateless codes are applied to track the truncation of receive images for various link ranges and angular offsets. A proof-of-concept optical communication system is implemented with an LCD display and a high-speed CMOS camera.
Auteurs: Boxiao Han;Steve Hranilovic;
Apparue dans: IEEE Journal on Selected Areas in Communications
Date publication: 01.-2018, volume: 36, issue:1, pages: 203 - 211
Editeur: IEEE
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» A Flexible 2.45-GHz Power Harvesting Wristband With Net System Output From −24.3 dBm of RF Power
Résumé:
This paper presents a flexible 2.45-GHz wireless power harvesting wristband that generates a net dc output from a −24.3-dBm RF input. This is the lowest reported system sensitivity for systems comprising a rectenna and impedance-matching power management. A complete system has been implemented comprising: a fabric antenna, a rectifier on rigid substrate, a contactless electrical connection between rigid and flexible subsystems, and power electronics impedance matching. Various fabric and flexible materials are electrically characterized at 2.45 GHz using the two-line and the T-resonator methods. Selected materials are used to design an all-textile antenna, which demonstrates a radiation efficiency above 62% on a phantom irrespective of location, and a stable radiation pattern. The rectifier, designed on a rigid substrate, shows a best-in-class efficiency of 33.6% at −20 dBm. A reliable, efficient, and wideband contactless connection between the fabric antenna and the rectifier is created using broadside-coupled microstrip lines, with an insertion loss below 1 dB from 1.8 to over 10 GHz. A self-powered boost converter with a quiescent current of 150 nA matches the rectenna output with a matching efficiency above 95%. The maximum end-to-end efficiency is 28.7% at −7 dBm. The wristband harvester demonstrates net positive energy harvesting from −24.3 dBm, a 7.3-dB improvement on the state of the art.
Auteurs: Salah-Eddine Adami;Plamen Proynov;Geoffrey S. Hilton;Guang Yang;Chunhong Zhang;Dibin Zhu;Yi Li;Steve P. Beeby;Ian J. Craddock;Bernard H. Stark;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 01.-2018, volume: 66, issue:1, pages: 380 - 395
Editeur: IEEE
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» A Flying Odor Compass to Autonomously Locate the Gas Source
Résumé:
The design of a flying odor compass is proposed for the localization of gas source. The compass is built on a quad-rotor helicopter and contains three gas sensors. A data processing method is proposed to estimate the direction which the odor comes from. The method adopts continuous wavelet transform and modulus maxima approaches to uncover the time difference information hidden in the gas sensor signals. Experiments have demonstrated the effectiveness of this design.
Auteurs: Bing Luo;Qing-Hao Meng;Jia-Ying Wang;Ming Zeng;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 01.-2018, volume: 67, issue:1, pages: 137 - 149
Editeur: IEEE
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» A Framework for Attack-Resilient Industrial Control Systems: Attack Detection and Controller Reconfiguration
Résumé:
Most existing industrial control systems (ICSs), such as building energy management systems (EMSs), were installed when potential security threats were only physical. With advances in connectivity, ICSs are now, typically, connected to communications networks and, as a result, can be accessed remotely. This extends the attack surface to include the potential for sophisticated cyber attacks, which can adversely impact ICS operation, resulting in service interruption, equipment damage, safety concerns, and associated financial implications. In this work, a novel cyber–physical security framework for ICSs is proposed, which incorporates an analytics tool for attack detection and executes a reliable estimation-based attack-resilient control policy, whenever an attack is detected. The proposed framework is adaptable to already implemented ICS and the stability and optimal performance of the controlled system under attack has been proved. The performance of the proposed framework is evaluated using a reduced order model of a real EMS site and simulated attacks.
Auteurs: Kaveh Paridari;Niamh O’Mahony;Alie El-Din Mady;Rohan Chabukswar;Menouer Boubekeur;Henrik Sandberg;
Apparue dans: Proceedings of the IEEE
Date publication: 01.-2018, volume: 106, issue:1, pages: 113 - 128
Editeur: IEEE
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» A Framework for Incorporation of Infeed Uncertainty in Power System Risk-Based Security Assessment
Résumé:
In this paper, a risk-based security assessment methodology is presented, which allows the assessment of operational security of a power system's future state under uncertainty deriving from varying topology scenarios (contingencies) and forecast errors (loads and renewable infeeds). The methodology models input uncertainty with a copula function-based Monte–Carlo (MC) framework. Furthermore, it provides the highest level of accuracy on initiating causes of failures through an AC power flow (AC PF) framework. Finally, it achieves speed in solution by the combination of two measures of risk. A fast screening tool, based on severity functions, allows us to quickly screen the system for the most severe states. A detailed analysis tool, based on an AC optimal power flow (AC OPF) framework and the notion of lost load, provides additional valuable information, including remedial actions to steer away from severe system states. This paper presents results from the application of the methodology proving the necessity of such a framework. It is shown that not taking into account stochastic dependence through a proper MC setup seriously underestimates system risk and that an AC framework is needed, as voltage deviations are shown to often be initiators of system collapse.
Auteurs: Martijn de Jong;Georgios Papaefthymiou;Peter Palensky;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 613 - 621
Editeur: IEEE
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» A Framework for Modeling and Optimizing Maintenance in Systems Considering Epistemic Uncertainty and Degradation Dependence Based on PDMPs
Résumé:
A modeling and optimization framework for the maintenance of systems under epistemic uncertainty is presented in this paper. The component degradation processes, the condition-based preventive maintenance, and the corrective maintenance are described through piecewise-deterministic Markov processes in consideration of degradation dependence among degradation processes. Epistemic uncertainty associated with component degradation processes is treated by considering interval-valued parameters. This leads to the formulation of a multi-objective optimization problem whose objectives are the lower and upper bounds of the expected maintenance cost, and whose decision variables are the periods of inspections and the thresholds for preventive maintenance. A solution method to derive the optimal maintenance policy is proposed by combining finite-volume scheme for calculation, differential evolution, and nondominated sorting differential evolution for optimization. An industrial case study is presented to illustrate the proposed methodology.
Auteurs: Yan-Hui Lin;Yan-Fu Li;Enrico Zio;
Apparue dans: IEEE Transactions on Industrial Informatics
Date publication: 01.-2018, volume: 14, issue:1, pages: 210 - 220
Editeur: IEEE
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» A Framework of Rapid Regional Tsunami Damage Recognition From Post-event TerraSAR-X Imagery Using Deep Neural Networks
Résumé:
Near real-time building damage mapping is an indispensable prerequisite for governments to make decisions for disaster relief. With high-resolution synthetic aperture radar (SAR) systems, such as TerraSAR-X, the provision of such products in a fast and effective way becomes possible. In this letter, a deep learning-based framework for rapid regional tsunami damage recognition using post-event SAR imagery is proposed. To perform such a rapid damage mapping, a series of tile-based image split analysis is employed to generate the data set. Next, a selection algorithm with the SqueezeNet network is developed to swiftly distinguish between built-up (BU) and nonbuilt-up regions. Finally, a recognition algorithm with a modified wide residual network is developed to classify the BU regions into wash away, collapsed, and slightly damaged regions. Experiments performed on the TerraSAR-X data from the 2011 Tohoku earthquake and tsunami in Japan show a BU region extraction accuracy of 80.4% and a damage-level recognition accuracy of 74.8%, respectively. Our framework takes around 2 h to train on a new region, and only several minutes for prediction.
Auteurs: Yanbing Bai;Chang Gao;Sameer Singh;Magaly Koch;Bruno Adriano;Erick Mas;Shunichi Koshimura;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 01.-2018, volume: 15, issue:1, pages: 43 - 47
Editeur: IEEE
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» A Fully Integrated High-Sensitivity Wide Dynamic Range PPG Sensor With an Integrated Photodiode and an Automatic Dimming Control LED Driver
Résumé:
This paper presents the design and implementation for a photoplethysmographic (PPG) sensor with an integrated photodiode and an automatic dimming control LED driver. The PPG front end is designed with a programmable low-pass cutoff frequency from 5 Hz up to 35 Hz, a high-pass cutoff frequency of 0.1 Hz, a total input referred noise current of 79 pA, and a maximum transimpedance gain of 144 dB $Omega $ . The sensor fabricated in 0.35- $mu text{m}$ CMOS technology and consumes 1.4 mA from 2.7 V–4 V single power supply. The integrated LED driver uses a duty cycle control at a pulse repetition frequency of 200 Hz and 1% duty cycle. The LED driver can supply four LEDs each with 10 mA. An automatic dimming control is implemented to reduce the LEDs current at strong PPG signal strength, to reduce the LEDs power consumption.
Auteurs: Mohamed Atef;Min Wang;Guoxing Wang;
Apparue dans: IEEE Sensors Journal
Date publication: 01.-2018, volume: 18, issue:2, pages: 652 - 659
Editeur: IEEE
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» A Fundamental Tradeoff Between Computation and Communication in Distributed Computing
Résumé:
How can we optimally trade extra computing power to reduce the communication load in distributed computing? We answer this question by characterizing a fundamental tradeoff between computation and communication in distributed computing, i.e., the two are inversely proportional to each other. More specifically, a general distributed computing framework, motivated by commonly used structures like MapReduce, is considered, where the overall computation is decomposed into computing a set of “Map” and “Reduce” functions distributedly across multiple computing nodes. A coded scheme, named “coded distributed computing” (CDC), is proposed to demonstrate that increasing the computation load of the Map functions by a factor of $r$ (i.e., evaluating each function at $r$ carefully chosen nodes) can create novel coding opportunities that reduce the communication load by the same factor. An information-theoretic lower bound on the communication load is also provided, which matches the communication load achieved by the CDC scheme. As a result, the optimal computation-communication tradeoff in distributed computing is exactly characterized. Finally, the coding techniques of CDC is applied to the Hadoop TeraSort benchmark to develop a novel CodedTeraSort algorithm, which is empirically demonstrated to speed up the overall job execution by $1.97times $ $3.39times $ , for typical settings of interest.
Auteurs: Songze Li;Mohammad Ali Maddah-Ali;Qian Yu;A. Salman Avestimehr;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 01.-2018, volume: 64, issue:1, pages: 109 - 128
Editeur: IEEE
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» A Gauss–Newton ADALINE for Dynamic Phasor Estimation of Power Signals and Its FPGA Implementation
Résumé:
This paper presents a new hybrid adaptive filter based on modified Gauss–Newton adaptive linear element (MGNA) for estimating the fundamental and harmonic phasors along with the frequency change of nonstationary power system signals useful in many application areas that include system control, digital relaying, state estimation, and also wide area systems. The proposed approach is used to minimize an objective function based on weighted square of the error using the MGNA. Moreover, the inverse of the Hessian matrix is computed assuming certain approximations to reduce the computational load and time consumption. Furthermore, it also uses recursive formulation using the estimated values from the previous time instant unlike the nonrecursive approaches, thereby exhibiting better performance in terms of accuracy and convergence. Besides, its simple structure makes it more suitable for real-time applications. In addition, the filter has been implemented on a field programmable gate array hardware and Xilinx 14.2 with the Sysgen software for the estimation of frequency, fundamental, and harmonic phasors of single and three-phase time-varying power system signals.
Auteurs: Sarita Nanda;Pradipta Kishore Dash;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 01.-2018, volume: 67, issue:1, pages: 45 - 56
Editeur: IEEE
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» A Generalized VNF Sharing Approach for Service Scheduling
Résumé:
Network function virtualization enables a flexible service provision by introducing the concept of virtual network function (VNF). Despite the importance of VNF scheduling, it is largely unexplored. In this letter, we propose a new model for VNF scheduling based on the min-plus algebra theory. The main idea of this model is to share the deployed VNF instances among different services, thus to improve the resource utilization and reduce the resource fragmentation generated by deploying many VNF instances. In addition, a weight-based VNF sharing scheduling approach is proposed in this model to achieve a fair scheduling among the arriving service requests. The experimental results show that the proposed model and approach are effective and efficient.
Auteurs: Bo Yi;Xingwei Wang;Min Huang;
Apparue dans: IEEE Communications Letters
Date publication: 01.-2018, volume: 22, issue:1, pages: 73 - 76
Editeur: IEEE
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» A Hierarchical Scheme for Utilizing Plug-In Electric Vehicle Power to Hedge Against Wind-Induced Unit Ramp Cycling Operations
Résumé:
Increasing wind power (WP) integration is forcing conventional units to go through more frequent and significant cycling operations, which would accelerate wear and tear to unit components and eventually affect the unit's lifespan. In this context, this paper proposes a hierarchical scheme to control the power of plug-in electric vehicles (PEVs) to mitigate unit ramp cycling (URC) operations. A general-form representation of the URC operation is proposed for the first time. At the top level of the hierarchical scheme, a system net load variation range (NLVR) is constructed first to capture the uncertainty in WP forecasts, and then the PEV power is scheduled to reshape the NLVR so as to minimize the URC operations that can be caused by the possible net load realizations in the NLVR. Based on updated WP forecasts, the middle-level dispatch model exempts overscheduled anti-URC regulation onus on PEVs to promote PEV charging. At the bottom level, a decentralized PEV charging control strategy is used to implement the PEV power dispatch instruction. Simulation results verify that the proposed scheme can avert the URC operations effectively, while preserve most of the desired PEV charging energy. Simulation results also show that the proposed scheme is more capable of withstanding WP forecast errors compared with its deterministic version and a benchmark scheme.
Auteurs: Xiao Luo;Shiwei Xia;Ka Wing Chan;Xi Lu;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 55 - 69
Editeur: IEEE
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» A High Linearity 24-GHz Down-Conversion Mixer Using Distributed Derivative Superposition Technique in 0.18- $mu text{m}$ CMOS Process
Résumé:
This letter presents a 24-GHz down-conversion mixer with built-in linearizer in 0.18- $mu text{m}$ CMOS process. The mixer attains −4.5 ± 0.6 dB conversion gain and 23-dBm IIP3 with 5-dBm local-oscillator power by adopting double-balanced Gilbert-cell mixers with a distributed derivative superposition linearizer. The improvement of IIP3 is 9 dB. The dc power consumption of the proposed mixer is 16 mW. This mixer has the best IIP3 compared with other published CMOS mixer in the K-band.
Auteurs: Hung-Hao Lin;Yu-Hsuan Lin;Huei Wang;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 49 - 51
Editeur: IEEE
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» A High-Definition LIDAR System Based on Two-Mirror Deflection Scanners
Résumé:
This paper addresses the problem of adopting a state-of-art laser marking system with a two-mirror deflection scanner to make a high-definition light detection and ranging (LIDAR) system. To this end, a galvanometer scanner is modeled with parameterization and then the well-known raster scanning strategy is analyzed considering the physical scanning movement and the minimum spanning tree. As a result of this analysis, the relationship between the field of view (FOV) of the captured image and the scanning speed is clearly described. Furthermore, sufficient conditions are derived for an acquired image to fully cover the FOV and also for captured objects to be well aligned for a target frame rate. Finally, a prototype LIDAR system is developed to verify the proposed concepts and to prove that it successfully generates images at various resolutions depending on the target frame rates. Experimental results show that the scanner achieves the frame rates of 17.6, 9.0, and 4.6 frames per second fps for image sizes of $240times 16$ , $240times 32$ , and $240times 64$ resolutions, respectively.
Auteurs: Xuan Truong Nguyen;Van Luan Dinh;Hyuk-Jae Lee;Hyun Kim;
Apparue dans: IEEE Sensors Journal
Date publication: 01.-2018, volume: 18, issue:2, pages: 559 - 568
Editeur: IEEE
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» A High-Gain ${X}$ -Band Overmoded Relativistic Klystron
Résumé:
A high-gain ${X}$ -band overmoded relativistic klystron is presented in this paper. The device mainly consists of an input cavity, two buncher cavities, and an output cavity. Moreover, two reflectors are added before and after the input cavity, therefore a standing wave is formed between the two reflectors, improving the initial modulation of the electron beam. With two sectional RF lossy materials inserted, the input cavity and the two buncher cavities are effectively isolated with each other. An additional reflector located just before the output cavity further reflects the backward-flowing power. Particle-in-cell simulations show that for a 10-kW injected microwave with a frequency of 9.37 GHz, the generated microwave power is 1.2 GW, corresponding to a beam-wave interaction efficiency of 30% and a gain of 50.8 dB. As the injected power increases from 10 to 100 kW, the frequency control range extends from 30 to 130 MHz.
Auteurs: Renzhen Xiao;Changhua Chen;Yuqun Deng;Jiawei Li;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 01.-2018, volume: 65, issue:1, pages: 263 - 269
Editeur: IEEE
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» A High-Precision Method of Phase-Derived Velocity Measurement and Its Application in Motion Compensation of ISAR Imaging
Résumé:
The existing methods for motion compensation in inverse synthetic aperture radar (ISAR) imaging are generally limited to the low-order target motion model, and require iterative optimization with limited velocity estimate precision and heavy computational burdens. This paper proposes a high-precision method of phase-derived velocity measurement (PDVM) and applies it to motion compensation of ISAR imaging. The method applies PDVM based on range profiles cross correlation to the translational velocity estimation of targets, and converts the velocity measurement results to the corresponding range increment. The equivalent phase-derived range measurement precision can reach the order of magnitude of millimeter (mm) or even sub-mm, which can satisfy the precision requirements of both envelope alignment and phase adjustment. The key to realizing PDVM is resolving phase ambiguity. The traditional method for resolving ambiguity has very high requirements for the signal-to-noise ratio (SNR). This work resolves ambiguity by combining multiframe data, i.e., by resolving ambiguity of multiframe data simultaneously instead of resolving ambiguity of single-frame data independently and correcting the above ambiguity-resolving results using a minimum-entropy method. Therefore, phase ambiguity can be correctly resolved under a relatively low SNR. Experimental results of an ISAR imaging of an airplane show that the method proposed in this paper can obtain high-quality ISAR imagery, and can efficiently realize robust imaging under the conditions of low SNR.
Auteurs: Huayu Fan;Lixiang Ren;Erke Mao;Quanhua Liu;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 01.-2018, volume: 56, issue:1, pages: 60 - 77
Editeur: IEEE
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» A Hybrid Boundary Element Model for Simulation and Optimization of Large Piezoelectric Micromachined Ultrasonic Transducer Arrays
Résumé:
A hybrid boundary element model is proposed for the simulation of large piezoelectric micromachined ultrasonic transducer (PMUT) arrays in immersion. Multiphysics finite element method (FEM) simulation of a single-membrane structure is used to determine stiffness and piezoelectrically induced actuation loading of the membranes. To simulate the arrays of membranes in immersion, a boundary element method is employed, wherein membrane structures are modeled by a surface mesh that is coupled mechanically by mass, stiffness, and damping matrices, and acoustically by a mutual impedance matrix. A multilevel fast multipole algorithm speeds up computation time and reduces memory usage, enabling the simulation of thousands of membranes in a reasonable time. The model is validated with FEM for a small 3 $times $ 3 matrix array for both square and circular membrane geometries. Two practical optimization examples of large PMUT arrays are demonstrated: membrane spacing of a 7 $times $ 7 matrix array with circular membranes, and material choice and top electrode coverage of a 32-element linear array with 640 circular membranes. In addition, a simple analytical approach to electrode optimization based on normal mode theory is verified.
Auteurs: Bernard Shieh;Karim G. Sabra;F. Levent Degertekin;
Apparue dans: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Date publication: 01.-2018, volume: 65, issue:1, pages: 50 - 59
Editeur: IEEE
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» A Hybrid Image Registration and Matching Framework for Real-Time Motion Tracking in MRI-Guided Radiotherapy
Résumé:
Objective: MRI-guided radiotherapy (MRIgRT) is an emerging treatment technique where anatomical and pathological structures are imaged through integrated MR-radiotherapy units. This work aims 1) at assessing the accuracy of optical-flow-based motion tracking in liver cine-MRI sequences; and 2) at testing a MRIgRT workflow combining similarity-based image matching with image registration. Methods: After an initialization stage, a set of template images is collected and registered to the first frame of the cine-MRI sequence. Subsequent incoming frames are either matched to the most similar template image or registered to the first frame when the similarity index is lower than a given threshold. The tracking accuracy was evaluated by considering ground-truth liver landmarks trajectories, as obtained through the scale-invariant features transform (SIFT). Results: Results on a population of 30 liver subjects show that the median difference between SIFT- and optical flow-based landmarks trajectories is 1.0 mm, i.e., lower than the cine-MRI pixel size (1.28 mm). The computational time of the motion tracking workflow (<50 ms) is suitable for real-time motion compensation in MRIgRT. Such time could be further reduced to ≍30 ms with limited loss of accuracy by the combined image matching/registration approach. Conclusion: The reported workflow allows us to track liver motion with accuracy comparable to robust feature matching. Its computational time is suitable for online motion monitoring. Significance: Real-time feedback on the patient anatomy is a crucial requirement for the treatment of mobile tumors using advanced motion mitigation strategies.
Auteurs: Matteo Seregni;Chiara Paganelli;Paul Summers;Massimo Bellomi;Guido Baroni;Marco Riboldi;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 01.-2018, volume: 65, issue:1, pages: 131 - 139
Editeur: IEEE
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» A Hybrid Regularization Technique for Solving Highly Nonlinear Inverse Scattering Problems
Résumé:
Solving inverse scattering problems (ISPs) for targets with high contrasts and/or large dimensions suffer from severe ill-posedness and strong nonlinearity. Recently, a family of new integral equations (NIE) has been proposed to tackle such problems, in which the multiple scattering effects in estimating contrasts during inversions are suppressed by the local wave effects. This effectively reduces the nonlinearity of ISPs by transforming the problems into a new form. As in most inversions, to achieve better (stabler and faster) inversion efficiency, proper regularization techniques are needed. This paper provides the detailed studies on the two different types of regularization techniques in the inversions with the NIE, i.e., the twofold subspace-based optimization method, directly applied in the modeling, and the total variation type multiplicative regularization, conventionally applied on the unknowns. We will show that how each regularization works with the NIE and how they work together with the NIE to obtain the better performance in terms of reducing the nonlinearity and increasing the stability of the inversions. Numerical tests against synthetic data and experimental data are provided to verify the interests.
Auteurs: Kuiwen Xu;Yu Zhong;Gaofeng Wang;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 01.-2018, volume: 66, issue:1, pages: 11 - 21
Editeur: IEEE
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» A K-Band Backscatter Fiducial for Continuous Calibration in Coherent Millimeter-Wave Imaging
Résumé:
We present a modulated ultrawideband backscatter calibration target (fiducial) intended for group delay calibration in large-aperture multitransceiver millimeter-wave imagers. The fiducial is designed to resemble a modulated point scatterer across the K-band (17.5–26.5 GHz). Multiple such fiducials may be used to mitigate thermal and mechanical drift across multiple transceivers comprising the imager. This approach allows tracking and removing both time-varying amplitude and phase drift in the RF hardware and associated cables. Backscatter modulation of the fiducial allows the system to separate the fiducial from the imaged scene and clutter in the environment. We show that the −10 dB beamwidth of the proposed fiducial is approximately 84° along the azimuth plane and 60° along the elevation plane. A proof of concept group delay calibration experiment is presented for a K-band laboratory setup, where a single fiducial and a metal plate target are placed in a scene together. After the backscatter-based calibration, the measured range error of the metal plate at a two-way slant distance of 70.54 cm is reduced to only 1.06 mm (0.15% position error).
Auteurs: Apoorva Sharma;Andreas Pedross-Engel;Daniel Arnitz;Claire M. Watts;David R. Smith;Matthew S. Reynolds;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 01.-2018, volume: 66, issue:1, pages: 431 - 438
Editeur: IEEE
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» A Large Comparison of Feature-Based Approaches for Buried Target Classification in Forward-Looking Ground-Penetrating Radar
Résumé:
Forward-looking ground-penetrating radar (FLGPR) has recently been investigated as a remote-sensing modality for buried target detection (e.g., landmines). In this context, raw FLGPR data are beamformed into images, and then, computerized algorithms are applied to automatically detect subsurface buried targets. Most existing algorithms are supervised, meaning that they are trained to discriminate between labeled target and nontarget imagery, usually based on features extracted from the imagery. A large number of features have been proposed for this purpose; however, thus far it is unclear as to which are the most effective. The first goal of this paper is to provide a comprehensive comparison of detection performance using existing features on a large collection of FLGPR data. Fusion of the decisions resulting from processing each feature is also considered. The second goal of this paper is to investigate two modern feature learning approaches from the object recognition literature: the bag-of-visual words and the Fisher vector for FLGPR processing. The results indicate that the new feature learning approaches lead to the best performing FLGPR algorithm. The results also show that fusion between existing features and new features yields no additional performance improvements.
Auteurs: Joseph A. Camilo;Leslie M. Collins;Jordan M. Malof;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 01.-2018, volume: 56, issue:1, pages: 547 - 558
Editeur: IEEE
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» A Learning Scheme for Microgrid Reconnection
Résumé:
This paper introduces a potential learning scheme that can dynamically predict the stability of the reconnection of subnetworks to a main grid. As the future electrical power systems tend toward smarter and greener technology, the deployment of self sufficient networks, or microgrids, becomes more likely. Microgrids may operate on their own or synchronized with the main grid, thus control methods need to take into account islanding and reconnecting of said networks. The ability to optimally and safely reconnect a portion of the grid is not well understood and, as of now, limited to raw synchronization between interconnection points. A support vector machine (SVM) leveraging real-time data from phasor measurement units is proposed to predict in real time whether the reconnection of a subnetwork to the main grid would lead to stability or instability. A dynamics simulator fed with preacquired system parameters is used to create training data for the SVM in various operating states. The classifier was tested on a variety of cases and operating points to ensure diversity. Accuracies of approximately 85% were observed throughout most conditions when making dynamic predictions of a given network.
Auteurs: Carter Lassetter;Eduardo Cotilla-Sanchez;Jinsub Kim;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 691 - 700
Editeur: IEEE
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» A Low Radar Cross Section and Low Profile Antenna Co-Designed With Absorbent Frequency Selective Radome
Résumé:
A low radar cross section (RCS) and low profile antenna co-designed with absorbent frequency selective radome (AFSR) is investigated. A pair of circular slot resonators is embedded on surface of the AFSR to realize a transmission window in the vertical polarization, while the wide absorption band is still maintained in the horizontal polarization. When a patch antenna is etched within the AFSR, where the metal grounds of the patch antenna and AFSR are co-used, the co-designed antenna with low RCS and low profile is thus realized. For demonstration, an AFSR is designed with its transmission window has a minimal insertion loss of 0.45 dB at 8.9 GHz, and two separate absorption bands (a lower absorption band from 4.8 to 7.5 GHz and an upper absorption band from 10 to 13 GHz) in the vertical polarization, a wide absorption band (from 4.5 to 12.5 GHz) in the horizontal polarization. A patch antenna etched within the AFSR is optimized to operate at 8.9 GHz, then it is simulated and fabricated. The measured results demonstrate that the proposed antenna not only has good radiation patterns, but also obtains significant RCS reduction.
Auteurs: Peng Mei;Xian Qi Lin;Jia Wei Yu;Peng Cheng Zhang;Abdelheq Boukarkar;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 01.-2018, volume: 66, issue:1, pages: 409 - 413
Editeur: IEEE
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» A Low-Loss Self-Packaged Magic-T With Compact Size Using SISL Technology
Résumé:
This letter proposes a low-loss self-packaged magic-T with compact size using substrate integrated suspended line (SISL) technology. The microstrip-slot transition is embedded inside the SISL multilayer structure and thus the radiation loss caused by the slot can be reduced to minimum. The measured results, which agree well with the simulation ones, show that from 5 to 9 GHz, i.e., 57% fractional bandwidth, the measured return loss of each port is better than about 10 dB, the measured isolation between difference port and sum port is better than 35 dB, and the measured amplitude imbalance and phase imbalance are ±0.8° and ±0.14 dB, respectively. The implemented magic-T has a compact size of $0.18lambda _{g}times 0.43lambda _{g}$ , which is much smaller than previous designs.
Auteurs: Yongqiang Wang;Kaixue Ma;Shouxian Mou;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 13 - 15
Editeur: IEEE
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» A Low-Noise CMOS Image Sensor With Digital Correlated Multiple Sampling
Résumé:
This paper presents a low noise CMOS image sensor using conventional 3T active pixel with Nwell/Psub diode as photo detector. Both fixed pattern noise (FPN) and temporal noise are suppressed by the proposed digital correlated multiple sampling (DCMS) technology. FPN and temporal noise from pixel, buffer circuit, and column-parallel ADC are analyzed in detail, and the total noise with DCMS is derived. General expression of 1/f noise with correlated multiple sampling is given, illustrating impact of delay time in DCMS. Output noise of image sensor, frame rate, power, and area are affected by order and oversampling ratio of sigma–delta ADC, which are discussed for practical design. A prototype CMOS image sensor with $800times 600$ pixel array and second-order incremental sigma–delta ADCs is implemented with the 0.35- $mu text{m}$ standard CMOS process. Measurement results of the implemented image sensor show a column FPN of 0.009%, an input referred noise of 3.5 $text{e}^{-}_{mathrm {mathbf {rms}}}$ , and a dynamic range of 84 dB with oversampling ratio of 255. This indicates that image sensor with low noise can be achieved by DCMS without the CIS process and column amplification.
Auteurs: Nan Chen;Shengyou Zhong;Mei Zou;Jiqing Zhang;Zhongshun Ji;Libin Yao;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 01.-2018, volume: 65, issue:1, pages: 84 - 94
Editeur: IEEE
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» A Low-Power Convolutional Neural Network Face Recognition Processor and a CIS Integrated With Always-on Face Detector
Résumé:
A Low-power convolutional neural network (CNN)-based face recognition system is proposed for the user authentication in smart devices. The system consists of two chips: an always-on CMOS image sensor (CIS)-based face detector (FD) and a low-power CNN processor. For always-on FD, analog–digital Hybrid Haar-like FD is proposed to improve the energy efficiency of FD by 39%. For low-power CNN processing, the CNN processor with 1024 MAC units and 8192-bit-wide local distributed memory operates at near threshold voltage, 0.46 V with 5-MHz clock frequency. In addition, the separable filter approximation is adopted for the workload reduction of CNN, and transpose-read SRAM using 7T SRAM cell is proposed to reduce the activity factor of the data read operation. Implemented in 65-nm CMOS technology, the $3.30 times 3.36$ mm2 CIS chip and the $4 times 4$ mm2 CNN processor consume 0.62 mW to evaluate one face at 1 fps and achieved 97% accuracy in LFW dataset.
Auteurs: Kyeongryeol Bong;Sungpill Choi;Changhyeon Kim;Donghyeon Han;Hoi-Jun Yoo;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 115 - 123
Editeur: IEEE
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» A Low-Power Hybrid-Integrated 40-Gb/s Optical Receiver in Silicon
Résumé:
A low-power hybrid-integrated 40-Gb/s optical receiver is reported. The receiver consists of a broadband photodiode fabricated in a 0.18- $mu text{m}$ Ge-on-SOI process packaged with an mm-wave electronic chip fabricated in a 0.13- $mu text{m}$ SiGe BiCMOS process. The electronic chip consists of a low-noise transimpedance amplifier front-end, a three-stage Cherry–Hooper limiting amplifier, an output driver, and an offset cancellation network. The effect of the bond-wires, as the interface between the photonic and electronic chips, on the overall performance of the receiver is studied. The sensitivity level remains better than −11.0 dBm (bit error rate $le 10^{-12}$ ) with bond-wire length variation from 300 to 600 $mu text{m}$ enabling a low-cost and reliable packaging solution for such optical receivers. The measured eye diagram has a 100-mVpp single-ended opening at 40 Gb/s. The receiver consumes 77 mW.
Auteurs: Zhe Xuan;Ran Ding;Yang Liu;Tom Baehr-Jones;Michael Hochberg;Firooz Aflatouni;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 01.-2018, volume: 66, issue:1, pages: 589 - 595
Editeur: IEEE
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» A Low-Power Speech Recognizer and Voice Activity Detector Using Deep Neural Networks
Résumé:
This paper describes digital circuit architectures for automatic speech recognition (ASR) and voice activity detection (VAD) with improved accuracy, programmability, and scalability. Our ASR architecture is designed to minimize off-chip memory bandwidth, which is the main driver of system power consumption. A SIMD processor with 32 parallel execution units efficiently evaluates feed-forward deep neural networks (NNs) for ASR, limiting memory usage with a sparse quantized weight matrix format. We argue that VADs should prioritize accuracy over area and power, and introduce a VAD circuit that uses an NN to classify modulation frequency features with 22.3- $mu text{W}$ power consumption. The 65-nm test chip is shown to perform a variety of ASR tasks in real time, with vocabularies ranging from 11 words to 145 000 words and full-chip power consumption ranging from 172 $mu text{W}$ to 7.78 mW.
Auteurs: Michael Price;James Glass;Anantha P. Chandrakasan;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 66 - 75
Editeur: IEEE
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» A Low-Profile Dual-Polarized High-Isolation MIMO Antenna Arrays for Wideband Base-Station Applications
Résumé:
A low-profile dual-polarized high-isolation multiple input multiple output (MIMO) antenna array for wideband base-station applications is presented in this paper. The proposed dual-polarized antenna element has the advantage of lower profile ( $0.067lambda $ ) by utilizing artificial magnetic conductor structure. The antenna array consisting of four elements is working within the frequency band from 2.4 to 3 GHz. Furthermore, decoupling branches among the elements are introduced to improve the isolation by about 10 dB. Both simulation and measured results indicate that the proposed dual-polarized antenna element has a good isolation over 28 dB. Moreover, the beamwidth of the antenna array can be effectively broadened by the adjustment of phase distributions of corresponding artificial material plane. Finally, a larger MIMO system is also investigated, and the simulation and measured results prove that dual-polarized dipole antenna MIMO array has good system performance.
Auteurs: Huiqing Zhai;Lei Xi;Yiping Zang;Long Li;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 01.-2018, volume: 66, issue:1, pages: 191 - 202
Editeur: IEEE
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» A Low-Reflectivity Vacuum Window for Rectangular Hollow Waveguides
Résumé:
The design and performance of a broadband and low-reflectivity millimeter-wave vacuum window for rectangular hollow waveguides are presented. A reflectivity below −15 dB is achieved over almost the full ${W}$ -band. The vacuum window is sufficiently compact, so that two separate channels fit into a single ConFlat CF-35 vacuum flange. The proposed vacuum window utilizes a well-known circuit concept based on two-quadrature hybrid couplers together with two identical vacuum barriers (similar to a balanced amplifier). Due to the dielectric discontinuity at the vacuum barrier, a part of the incident wave is transmitted and another part is reflected. A hybrid lattice network recombines the transmitted signals and reroutes all reflected power to absorbers. The proposed low-reflectivity vacuum window has been fabricated in the WR10 waveguide technology. Broadband branch-guide couplers enable an operational frequency range of 75–105 GHz. Ultrahigh vacuum compatibility is verified by a helium leak rate test, and electrical measurements show good agreement with full-wave simulations.
Auteurs: Christian Koenen;Gerhard F. Hamberger;Uwe Siart;Thomas F. Eibert;Hans-Ulrich Nickel;Garrard D. Conway;Ulrich Stroth;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 01.-2018, volume: 66, issue:1, pages: 128 - 135
Editeur: IEEE
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» A Measurement Technique for Infrared Emissivity of Epoxy-Based Microwave Absorbing Materials
Résumé:
Infrared (IR) emissivity is a critical parameter for modeling and predicting heat transfer by radiation. Microwave absorbing materials, having a high emissivity in the microwave spectrum, are crucial in a wide array of applications, such as electromagnetic interference mitigation, stealth technology, and microwave remote sensing and radiometer calibration. Accurate knowledge of the thermal properties of these materials is necessary for efficient design and optimization of these types of systems. Typical microwave absorbing materials consist of a dielectric epoxy material impregnated with a lossy material, such as iron or carbon. We study a novel cryogenically compatible epoxy-based absorber material that has been loaded with varying concentrations of carbonyl iron powder (CIP). We study six materials with CIP concentrations of 0%, 5%, 10%, 20%, 30%, and 50% by tap volume. We use a commercial IR camera with sensitivity in the range 7.5– $13~mu text{m}$ to measure the radiance of the samples and a waterbath IR blackbody at ten temperatures between about 19 °C and 45 °C. A linear Deming fitting is performed, considering uncertainties in both the measured parameters, and the slope of the linear fit is shown to be the IR emissivity, averaged over the spectral response of the camera. The emissivity ranges between 0.868 and 0.757, decreasing monotonically as a function of iron carbonyl concentration between 0% and 50%. The uncertainty of the emissivity determination method is derived and presented. The uncertainty of the presented method is shown to be no larger than 3.3% for all measured samples.
Auteurs: Derek A. Houtz;Dazhen Gu;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 01.-2018, volume: 15, issue:1, pages: 48 - 52
Editeur: IEEE
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» A Method for Collecting Single Cell Suspensions Using an Ultrasonic Pump
Résumé:
The presence of cell aggregates in cell suspensions may reduce cell culture efficiency because they can induce apoptosis and inhibit proliferation. To avoid this problem, this study proposes a novel method for collecting single cell suspensions from culture chambers for subculture using an ultrasonic pump driven by the squeeze film effect. First, we developed a cell culture device consisting of a cell culture substrate with a piezoelectric ceramic disk glued to the back, so that we can elicit resonance vibration of the substrate. A glass pipe is then placed vertically against the cell culture substrate with a slight gap (corresponding to cell diameter) between the pipe and the substrate. By exciting an out-of-plane resonance vibration of the cell culture substrate, we can collect a cell suspension from the cell culture chamber. Since the gap distance between the glass pipe and the cell culture substrate corresponds to cell diameter, the collected cell suspension only contains single cells. We evaluated the capability of the developed cell suspension pumping system and the proliferation of the collected cells with C2C12 myoblast cells. The ratio of single cells in the cell suspension was improved by up to 9.6% compared with that of suspensions collected by the control method (traditional pipetting). Moreover, after cultivating the collected cells for 72 hr, the cells collected by our method proliferated 13.6% more than those collected by the control method. These results suggest that the proposed method has great potential for improving the cultivation efficiency of adhesive cell culture.
Auteurs: Misa Nakao;Yuta Kurashina;Chikahiro Imashiro;Kenjiro Takemura;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 01.-2018, volume: 65, issue:1, pages: 224 - 231
Editeur: IEEE
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» A Method for Measuring 3-D Surface Deformations With InSAR Based on Strain Model and Variance Component Estimation
Résumé:
Interferometric synthetic aperture radar (InSAR) technique is a proven technique for measuring 3-D surface deformations by combining InSAR measurements from different techniques (i.e., differential InSAR, multiaperture InSAR, and pixel offset-tracking) and different tracks (i.e., ascending and descending) on a pixel-by-pixel basis. However, it is difficult to obtain the exact a priori variances or weights for such different kinds of InSAR measurements, resulting in inaccurate estimations of 3-D deformations. This paper proposes a method to retrieve 3-D deformations with InSAR by integrating the strain model and variance component estimation algorithm, which can exploit the spatial correlation of the adjacent points’ deformations and produce accurate weights for multiple InSAR measurements. The proposed method is assessed with both simulated and real data sets. The results have shown that the proposed method can accurately measure 3-D surface deformations associated with geohazards, and even those occurring in a transient or short-term period (e.g., earthquake and volcanic eruption). In the case study of the 2007 eruption of Kilauea Volcano (Hawai’i), improvements of 51.2%, 22.4%, and 18.5% have been achieved for the derived east, north, and up displacements, respectively, with respect to those derived from the classical weighted least squares method.
Auteurs: Ji-Hong Liu;Jun Hu;Zhi-Wei Li;Jian-Jun Zhu;Qian Sun;Jie Gan;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 01.-2018, volume: 56, issue:1, pages: 239 - 250
Editeur: IEEE
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» A Method to Realize Robust Flexible Electronically Tunable Antennas Using Polymer-Embedded Conductive Fabric
Résumé:
A new approach to realize robust, flexible, and electronically tunable wearable antennas is presented. Conductive fabric is used to form the conducting parts of the antenna on a polydimethylsiloxane (PDMS) substrate. Then the antenna and the lumped (active and passive) elements, required for electronic tuning and RF choking, are fully encapsulated with additional layers of PDMS. As a concept demonstration, a new frequency-reconfigurable antenna has been designed and fabricated. The details of the prototype manufacturing process are described. Two UWB human muscle equivalent phantoms were also fabricated for testing purposes. Furthermore, the antenna was subjected to several investigations on its RF performance (both in free space and on a flat phantom) and mechanical stability. The latter includes bending tests on several locations on a human-body shaped phantom and washing in a household washing machine. Good agreement between predicted and experimental results (both in free space and on the phantom) is observed, validating the proposed concept. The tests demonstrated that lumped components and other antenna parts remained intact and in working order even under extreme bending (to a bending radius of 28 mm) and after washing, thus maintaining the overall antenna performance including good frequency reconfigurability from 2.3 to 2.68 GHz. To the best of our knowledge, all these features have never been demonstrated in previously published electronically tunable antennas.
Auteurs: Roy B. V. B. Simorangkir;Yang Yang;Karu P. Esselle;Basit A. Zeb;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 01.-2018, volume: 66, issue:1, pages: 50 - 58
Editeur: IEEE
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» A Methodological Approach to Model-Driven Design and Development of Automation Systems
Résumé:
The growing complexity of industrial automation demands the adoption of software engineering principles for improving the development process of control systems. This paper presents a methodological approach to the design and development of complex automation systems relying on model-driven engineering (MDE). A benefit of this approach is the integration of methods and techniques widespread within the automation discipline with modern MDE techniques guiding the designer through the development phases. A second advantage is to add flexibility enough to adapt the steps to the needs of the system under design. Finally, the architecture presented is prepared to be adapted to methodology extensions to cover other aspects of automation systems. The framework is based on domain models that are defined through the development phases using the terminology of the automation field. Using model transformations both documentation about system analysis and design and the skeleton of software units are automatically generated. A proof-of-concept tool has been developed that has been tested on the design of medium-complexity projects to assess the impact of its use with respect to project documentation and maintenance.

Note to Practitioners—Control software development can be considered one of the challenges in automation field for achieving leadership in the future economic market. This work presents a model-driven engineering-based approach making use of both automation and software engineering methods and techniques for developing automation control systems. The framework implements the methodology for industrial automation systems ( ${rm MeiA}_{bullet }$ ) for guiding developers through the development phases and generates the analysis and design documentation using domain terminology, the design documentation that involves the minimal units of design, and the pro- ram organization units in one-to-one correspondence with the minimal units of design. From a practical point of view, it should be highly emphasized that developers of automation projects benefit from more structured designs, reduced number of errors, and improved project documentation.

Auteurs: María Luz Alvarez;Isabel Sarachaga;Arantzazu Burgos;Elisabet Estévez;Marga Marcos;
Apparue dans: IEEE Transactions on Automation Science and Engineering
Date publication: 01.-2018, volume: 15, issue:1, pages: 67 - 79
Editeur: IEEE
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» A Modified Frequency Domain Condition for the Physical Realizability of Linear Quantum Stochastic Systems
Résumé:
This paper is concerned with a modified version of the frequency domain physical realizability (PR) condition for linear quantum systems. We consider open quantum systems whose dynamic variables satisfy the canonical commutation relations of an open quantum harmonic oscillator and are governed by linear quantum stochastic differential equations (QSDEs). In order to correspond to physical quantum systems, these QSDEs must satisfy PR conditions. We provide a relatively simple proof that the PR condition is equivalent to the frequency domain $(J,J)$-unitarity of the input–output transfer function and orthogonality of the feedthrough matrix of the system without the technical spectral assumptions required in previous work. We also show that the poles and transmission zeros associated with the transfer function of PR linear quantum systems are the mirror reflections of each other about the imaginary axis. An example is provided to illustrate the results.
Auteurs: Arash Kh. Sichani;Ian R. Petersen;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 01.-2018, volume: 63, issue:1, pages: 277 - 282
Editeur: IEEE
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» A Modified S-Transform and Random Forests-Based Power Quality Assessment Framework
Résumé:
The proposed work aims at the accurate detection and classification of various single and multiple power quality (PQ) disturbances. To this end, a modified optimal fast discrete Stockwell transform (ST) with random forests (RF) classifier-based PQ detection framework has been proposed in this paper. In modified ST, a single signal-dependent window is introduced, with optimally selected window parameters via energy concentration maximization based constraint optimization. As a result of which accurate time-frequency localization of various PQ events is achieved, with sharper energy concentration. In classification stage, the proposed PQ framework utilizes the RF-based classifier, which follows the bagging approach by random selection of features and data points, at each node, to train the classifier. Decision stumps are used as weak classifiers, and using a simple majority voting of these decision stumps, RF builds a strong classifier. The RF gives less variance and less bias estimation due to injection of randomness into the training phase, and its performance is found to be reasonably immune to input parameter selection. As a result of this, the classification results of the proposed PQ framework are found to be very accurate and quite insensitive to the presence of noise in the data. Various test cases are presented in this paper to clearly demonstrate the superiority of the proposed scheme. The proposed approach has also been tested on real field data and very promising results have been obtained.
Auteurs: Motakatla Venkateswara Reddy;Ranjana Sodhi;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 01.-2018, volume: 67, issue:1, pages: 78 - 89
Editeur: IEEE
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» A Monolithically Integrated Large-Scale Optical Phased Array in Silicon-on-Insulator CMOS
Résumé:
A large-scale monolithic silicon nanophotonic phased array on a chip creates and dynamically steers a high-resolution optical beam in free space, enabling emerging applications in sensing, imaging, and communication. The scalable architecture leverages sub-array structure, mitigating the impact of process variation on the phased array performance. In addition, sharing control electronics among multiple optical modulators in the scalable architecture reduces the number of digital-to-analog converters (DACs) required for an $N^{2}$ array from $mathcal {O}(N^{2})$ to $mathcal {O}(N)$ , allowing a small silicon footprint. An optical phased array for 1550-nm wavelength with 1024 uniformly spaced optical grating antennas, 1192 optical variable phase shifters, and 168 optical variable attenuators is integrated into a 5.7 mm $times$ 6.4 mm chip in a commercial 180-nm silicon-on-insulator RF CMOS technology. The control signals for the optical variable phase shifters and attenuators are provided by 136 DACs with 14-bit nonuniform resolution using 2.5-V input-output transistors. The implemented phased array can create 0.03° narrow optical beams that can be steered unambiguously within ±22.5°.
Auteurs: SungWon Chung;Hooman Abediasl;Hossein Hashemi;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 275 - 296
Editeur: IEEE
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» A Motion Planning Strategy for the Active Vision-Based Mapping of Ground-Level Structures
Résumé:
This paper presents a strategy to guide a mobile ground robot equipped with a camera or depth sensor, in order to autonomously map the visible part of a bounded 3-D structure. We describe motion planning algorithms that determine appropriate successive viewpoints and attempt to fill holes automatically in a point cloud produced by the sensing and perception layer. The emphasis is on accurately reconstructing a 3-D model of a structure of moderate size rather than mapping large open environments, with applications for example in architecture, construction, and inspection. The proposed algorithms do not require any initialization in the form of a mesh model or a bounding box, and the paths generated are well adapted to situations where the vision sensor is used simultaneously for mapping and for localizing the robot, in the absence of additional absolute positioning system. We analyze the coverage properties of our policy, and compare its performance with the classic frontier-based exploration algorithm. We illustrate its efficacy for different structure sizes, levels of localization accuracy, and range of the depth sensor, and validate our design on a real-world experiment. Note to Practitioners—The objective of this paper is to automate the process of building a 3-D model of a structure of interest that is as complete as possible, using a mobile camera or depth sensor, in the absence of any prior information about this structure. Given that increasingly robust solutions for the visual simultaneous localization and mapping problem are now readily available, the key challenge that we address here is to develop motion planning policies to control the trajectory of the sensor in a way that improves the mapping performance. We target in particular scenarios where no external absolute positioning system is available, such as mapping certain indoor environments where GPS signals are blocked. In this case, it is often important to revisi- previously seen locations relatively quickly, in order to avoid excessive drift in the dead-reckoning localization system. Our system works by first determining the boundaries of the structure, before attempting to fill the holes in the constructed model. Its performance is illustrated through simulations, and a real-world experiment performed with a depth sensor carried by a mobile manipulator.
Auteurs: Manikandasriram Srinivasan Ramanagopal;André Phu-Van Nguyen;Jerome Le Ny;
Apparue dans: IEEE Transactions on Automation Science and Engineering
Date publication: 01.-2018, volume: 15, issue:1, pages: 356 - 368
Editeur: IEEE
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» A Multi-Chain Merged Tapped Delay Line for High Precision Time-to-Digital Converters in FPGAs
Résumé:
Field programmable gate array (FPGA)-based time-to-digital converters (TDCs) use a tapped delay line (TDL) for time interpolation to yield a sub-clock time resolution. The granularity and uniformity of delay cells in TDL determines achievable TDC time precision. To gain small delay cells in TDL, we propose a new TDL architecture by merging multiple conventional delay chains to obtain very fine intrinsic cell delays. The uniformity of these cell delays is improved by a bin decimation method so that the time interpolation with the TDL has minimum nonlinearity error. To evaluate the performance improvement using the new TDL architecture, two identical TDC channels with 1-chain, 2-chain, and 4-chain merged TDLs, respectively, were implemented in a Xilinx Kintex-7 FPGA. For time-intervals in the range from 0 to 50 ns, the average RMS precisions of these TDC pairs were measured as 8.5 ps, 5.3 ps, and 4.3 ps, respectively. The test results confirm that the proposed TDL architecture is an FPGA-independent effective method for boosting TDC precision without significant increase in hardware complexity and logic resource consumption.
Auteurs: Yonggang Wang;Qiang Cao;Chong Liu;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 01.-2018, volume: 65, issue:1, pages: 96 - 100
Editeur: IEEE
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» A Multi-Class Tactile Brain–Computer Interface Based on Stimulus-Induced Oscillatory Dynamics
Résumé:
We proposed a multi-class tactile brain–computer interface that utilizes stimulus-induced oscillatory dynamics. It was hypothesized that somatosensory attention can modulate tactile-induced oscillation changes, which can decode different sensation attention tasks. Subjects performed four tactile attention tasks, prompted by cues presented in random order and while both wrists were simultaneously stimulated: 1) selective sensation on left hand (SS-L); 2) selective sensation on right hand (SS-R); 3) bilateral selective sensation; and 4) selective sensation suppressed or idle state (SS-S). The classification accuracy between SS-L and SS-R (79.9 ± 8.7%) was comparable with that of a previous tactile BCI system based on selective sensation. Moreover, the accuracy could be improved to an average of 90.3 ± 4.9% by optimal class-pair and frequency-band selection. Three-class discrimination had an accuracy of 75.2 ± 8.3%, with the best discrimination reached for the classes SS-L, SS-R, and SS-S. Finally, four classes were classified with an accuracy of 59.4 ± 7.3%. These results show that the proposed system is a promising new paradigm for multi-class BCI.
Auteurs: Lin Yao;Mei Lin Chen;Xinjun Sheng;Natalie Mrachacz-Kersting;Xiangyang Zhu;Dario Farina;Ning Jiang;
Apparue dans: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Date publication: 01.-2018, volume: 26, issue:1, pages: 3 - 10
Editeur: IEEE
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» A Multicommodity Flow-Based Detailed Router With Efficient Acceleration Techniques
Résumé:
Detailed routing is an important stage in very large scale integrated physical design. Due to the extreme scaling of transistor feature size and the complicated design rules, ensuring routing completion without design rule checking (DRC) violations becomes more and more difficult. Studies have shown that the low routing quality partly results from nonoptimal net-ordering nature of traditional sequential methods. The concurrent routing strategy is always based on an NP-hard model, thus is at a disadvantage in runtime. In this paper, we present a novel concurrent detailed routing algorithm that routes all nets simultaneously. Based on the multicommodity flow model, detailed routing problem with complex design rule constraints is formulated as an integer linear programming. Some model simplification heuristics and efficient model solving algorithms are proposed to improve the runtime. Experimental results show that, the proposed algorithms can reduce the DRC violations by 80%, meanwhile can reduce wirelength and via count by 5% and 8% compared with an industry tool. In addition, the proposed algorithm is general that it can be adopted as an incremental detailed router to refine a routing solution, so the number of DRC violations that industry tool cannot fix are further reduced by 27%.
Auteurs: Xiaotao Jia;Yici Cai;Qiang Zhou;Bei Yu;
Apparue dans: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Date publication: 01.-2018, volume: 37, issue:1, pages: 217 - 230
Editeur: IEEE
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» A Multistandard Method of Network Analyzer Self-Calibration—Generalization of Multiline TRL
Résumé:
This paper presents a statistical self-calibration procedure for two-port vector network analyzers (VNAs). It is a generalization of the Multiline thru-reflect-line (TRL) method and allows to combine the information of multiple A-standards, which can be realized by any matched networks. Moreover, the reflect standard is replaced by a more general network standard as a symmetrical network that may have nonzero transmission. In consequence, this method offers more flexibility in the choice of calibration standards and an extended bandwidth especially toward lower frequencies. At the same time, the improved accuracy over conventional methods persists, as well as the simple implementation, avoiding iterative solutions. The presented error analysis yields some new insights on the choice of calibration standards. In addition, a method is provided to modify the performed weighting of the information of different standards.
Auteurs: Bernd Hofmann;Stephan Kolb;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 01.-2018, volume: 66, issue:1, pages: 245 - 254
Editeur: IEEE
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» A Nano-Watt MOS-Only Voltage Reference With High-Slope PTAT Voltage Generators
Résumé:
This brief presents an MOS-only voltage reference circuit with high-slope proportional-to-absolute-temperature (PTAT) voltage generators for ultra-low-power applications. Biased by a nano-ampere current reference circuit, the PTAT voltage generator is realized by an asymmetrical differential cell with two additional cross-coupled nMOS/pMOS pairs, which enhance the slope of the PTAT voltage remarkably. As a result, only two cascaded PTAT stages are used to compensate the complementary-to-absolute-temperature voltage generated directly by a diode-connected nMOS in the current reference circuit. Therefore, much power and chip area can be saved. A trimming circuit is also adopted to compensate the process-related reference voltage variations. The experimental results of the proposed reference circuit fabricated in a 0.18- $ {mu }$ m standard CMOS process demonstrate that the circuit could operate under a minimum supply voltage of 1 V, and generate a reference voltage of 756 mV with temperature coefficient of 74 and 49.6 ppm/°C under 1-V and 1.8-V power supply, respectively. The proposed circuit consumes only 23 nA under a 1-V power supply, and the active area is only 95 $ {mu }text{m},, {times } ,, 170 ~{mu }text{m}$ .
Auteurs: Hong Zhang;Xipeng Liu;Jie Zhang;Hongshuai Zhang;Jijun Li;Ruizhi Zhang;Shuai Chen;Anthony Chan Carusone;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 01.-2018, volume: 65, issue:1, pages: 1 - 5
Editeur: IEEE
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» A New Amplification Regime for Traveling Wave Tubes With Third-Order Modal Degeneracy
Résumé:
Engineering of the eigenmode dispersion of slow wave structures (SWSs) to achieve desired modal characteristics is an effective approach to enhance the performance of high-power traveling wave tube (TWT) amplifiers or oscillators. We investigate here for the first time a new synchronization regime in TWTs based on SWSs operating near a third-order degeneracy condition in their dispersion. This special three-eigenmode synchronization is associated with a stationary inflection point (SIP) that is manifested by the coalescence of three Floquet-Bloch eigenmodes in the SWS. We demonstrate the special features of “cold” (without electron beam) periodic SWSs with SIP modeled as coupled transmission lines and investigate resonances of SWSs of finite length. We also show that by tuning parameters of a periodic SWS, one can achieve an SIP with nearly ideal flat dispersion relationship with zero group velocity or a slightly slanted one with a very small (positive or negative) group velocity leading to different operating schemes. The SIP structure when synchronized with an electron beam has potential benefits for amplification which include: 1) gain enhancement; 2) gain-bandwidth product improvement; and 3) higher power efficiency, when compared to conventional Pierce-like TWTs. The proposed theory paves the way for a new approach for potential improvements in gain, power efficiency, and gain-bandwidth product in high-power microwave amplifiers.
Auteurs: Farshad Yazdi;Mohamed A. K. Othman;Mehdi Veysi;Alexander Figotin;Filippo Capolino;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 01.-2018, volume: 46, issue:1, pages: 43 - 56
Editeur: IEEE
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» A New Approach to Track Multiple Vehicles With the Combination of Robust Detection and Two Classifiers
Résumé:
It plays an important role to accurately track multiple vehicles in intelligent transportation, especially in intelligent vehicles. Due to complicated traffic environments it is difficult to track multiple vehicles accurately and robustly, especially when there are occlusions among vehicles. To alleviate these problems, a new approach is proposed to track multiple vehicles with the combination of robust detection and two classifiers. An improved ViBe algorithm is proposed for robust and accurate detection of multiple vehicles. It uses the gray-scale spatial information to build dictionary of pixel life length to make ghost shadows and object’s residual shadows quickly blended into the samples of the background. The improved algorithm takes good post-processing method to restrain dynamic noise. In this paper, we also design a method using two classifiers to further attack the problem of failure to track vehicles with occlusions and interference. It classifies tracking rectangles with confidence values between two thresholds through combining local binary pattern with support vector machine (SVM) classifier and then using a convolutional neural network (CNN) classifier for the second time to remove the interference areas between vehicles and other moving objects. The two classifiers method has both time efficiency advantage of SVM and high accuracy advantage of CNN. Comparing with several existing methods, the qualitative and quantitative analysis of our experiment results showed that the proposed method not only effectively removed the ghost shadows, and improved the detection accuracy and real-time performance, but also was robust to deal with the occlusion of multiple vehicles in various traffic scenes.
Auteurs: Weidong Min;Mengdan Fan;Xiaoguang Guo;Qing Han;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 01.-2018, volume: 19, issue:1, pages: 174 - 186
Editeur: IEEE
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» A New Axial Flux Permanent Magnet Machine
Résumé:
This paper presents a new axial flux permanent magnet machine, named ring winding axial flux machine (AFM). The ring winding AFM (RWAFM) takes the advantage of segmented stator of yokeless and segmented armature topology with those of decoupled phases and ring winding of transverse flux topology. In this paper, the geometry of the RWAFM is introduced in detail. Furthermore, the working principle and torque production theory are discussed. To validate the concept and confirm manufacturability of the proposed topology, a prototype is fabricated. The performance of the RWAFM is studied through experimental tests, 3-D finite-element simulations, and analytical discussions.
Auteurs: Pourya Ojaghlu;Aboalfazl Vahedi;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 01.-2018, volume: 54, issue:1, pages: 1 - 6
Editeur: IEEE
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» A New Heuristic for $N$ -Dimensional Nearest Neighbor Realization of a Quantum Circuit
Résumé:
One of the main challenges in quantum computing is to ensure error-free operation of the basic quantum gates. There are various implementation technologies of quantum gates for which the distance between interacting qubits must be kept within a limit for reliable operation. This leads to the so-called requirement of neighborhood arrangements of the interacting qubits, often referred to as nearest neighbor (NN) constraint. This is typically achieved by inserting SWAP gates in the quantum circuits, where a SWAP gate between two qubits exchanges their states. Minimizing the number of SWAP gates to provide NN compliance is an important problem to solve. A number of approaches have been proposed in this regard, based on local and global ordering techniques. In this paper, a generalized approach for combined local and global ordering of qubits have been proposed that is based on an improved heuristic for cost estimation and is also scalable. The approach can be extended to ${N}$ -dimensional arrangement of qubits, for any arbitrary values of ${N}$ . Practical constraints, however, restrict the maximum value of ${N}$ to 3. Extensive experiments on benchmark functions have been carried out to evaluate the performance in terms of SWAP gate requirements. 3-D organization of qubits shows average reductions of 6.7% and 37.4%, respectively, in the number of SWAP gates over 2-D and 1-D organizations. Also compared to the best 2-D and 1-D results reported in the literature, on the average 8.7% and 8.4% reductions, respectively, are observed.
Auteurs: Abhoy Kole;Kamalika Datta;Indranil Sengupta;
Apparue dans: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Date publication: 01.-2018, volume: 37, issue:1, pages: 182 - 192
Editeur: IEEE
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» A New Iron Loss Model for Temperature Dependencies of Hysteresis and Eddy Current Losses in Electrical Machines
Résumé:
In this paper, the different temperature dependencies of hysteresis and eddy current losses of non-oriented Si-steel laminations are investigated. The measured iron loss results show that both the hysteresis and eddy current losses vary linearly with temperature between 40 °C to 100 °C, a typical temperature range of electrical machines. Varying rates of hysteresis and eddy current losses with the temperature are different and fluctuate with flux density and frequency. Based on this, an improved iron loss model which can consider temperature dependencies of hysteresis and eddy current losses separately is developed. Based on the improved iron loss model, the temperature influence on the iron loss can be fully considered by measuring iron losses at only two different temperatures. The investigation is experimentally validated by both the tests based on a ring specimen and an electrical machine.
Auteurs: Shaoshen Xue;Jianghua Feng;Shuying Guo;Jun Peng;W. Q. Chu;Z. Q. Zhu;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 01.-2018, volume: 54, issue:1, pages: 1 - 10
Editeur: IEEE
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» A New LDPC Coded Scheme for Two-User Gaussian Multiple Access Channels
Résumé:
We propose a new low-density parity-check coded scheme for two-user Gaussian multiple access channels (GMACs) with equal rate and equal average power constraints. In the proposed scheme, we divide a code word into two parts with equal length and transmit them by using BPSK signals with two power levels. Two users use the two power levels alternatively to avoid ambiguity problem in two-user GMACs. We optimize the ratio between the two power levels to minimize the required average signal-to-noise ratio for a given rate. We also design a joint decoding algorithm for our proposed scheme. Numerical results show that the proposed scheme has a better bit error rate performance, compared with the existing schemes.
Auteurs: Junyi Du;Liang Zhou;Lei Yang;Shenglong Peng;Jinhong Yuan;
Apparue dans: IEEE Communications Letters
Date publication: 01.-2018, volume: 22, issue:1, pages: 21 - 24
Editeur: IEEE
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» A New Phenomenon in Semi-Insulating 4H-SiC Photoconductive Semiconductor Switches
Résumé:
A new oscillational phenomenon has been found in high-biased semi-insulating (SI) 4H-SiC photoconductive semiconductor switches (PCSSs) with high densities of vanadium and nitrogen dopants, and this oscillational phenomenon has no relationship with the laser wavelength, bias voltage, the charge capacitor, and the shape/size of the 4H-SiC PCSS. This paper shows that the photo activated charge domain theory in SI GaAs PCSS may explain this phenomenon. Due to the high densities of vanadium and nitrogen dopants, the intervalley scattering may occur in the 4H-SiC PCSS, and the space charge field region will appear in the 4H-SiC PCSS for the electrons accumulation. This region looks upon an equivalent capacitor, when the accumulation of the electrons is over, the equivalent capacitor will discharge, and the oscillational phenomenon appears.
Auteurs: Chongbiao Luan;Boting Li;Juan Zhao;Jinshui Xiao;Xun Ma;Hongtao Li;Yupeng Huang;Longfei Xiao;Xiangang Xu;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 01.-2018, volume: 65, issue:1, pages: 172 - 175
Editeur: IEEE
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» A New Pseudo Load Profile Determination Approach in Low Voltage Distribution Networks
Résumé:
Low voltage (LV) state estimation in distribution networks mainly relies on pseudo measurements because the real-time monitoring is impossible for all customers. This paper presents a new method to determine the pseudo load profiles (PLPs) of customers with small consumptions connected to the LV distribution networks. This method is comprised of two stages. First, a new frequency-based clustering algorithm is proposed to extract the essential load patterns of limited number of customers who are equipped by smart meters and are called as sample customers. The superior performance of the proposed clustering algorithm is also shown in comparison with three of the most widely used clustering methods: k-means, self-organizing maps and hierarchical algorithms. In the second stage, a new approach is proposed to estimate the daily energy consumptions two weeks ahead for other customers who are not equipped by smart meters by using their previous billing cycle energy consumptions and the load data of sample customers. The PLP of a customer is obtained by multiplying the estimated daily energy consumption by the corresponding normalized load pattern. Studies have been conducted on the data of a real distribution system to verify the proposed method and to show its application for the PLP estimation of distribution networks.
Auteurs: Yaser Raeisi Gahrooei;Amin Khodabakhshian;Rahmat-Allah Hooshmand;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 01.-2018, volume: 33, issue:1, pages: 463 - 472
Editeur: IEEE
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» A Nitrided Interfacial Oxide for Interface State Improvement in Hafnium Zirconium Oxide-Based Ferroelectric Transistor Technology
Résumé:
We examine the nature of the interface states induced during the integration of ferroelectric hafnium zirconium oxide on silicon. Metal-ferroelectric-insulator-silicon capacitors, with a thin layer of hafnium zirconium oxide grown by atomic layer deposition as the ferroelectric and various interfacial oxide layers as the insulator, are investigated. Since a high-temperature post-annealing is necessary to induce the formation of the ferroelectric phase in this oxide stack, the integrity of the oxide/silicon interface must be preserved after high-temperature processing. As such, we show that a nitrided interlayer provides an improved midgap interface state density among all interfacial oxides investigated. Furthermore, we quantify the interface states using the ac conductance technique and model the interface trap distribution across the silicon bandgap in order to explain and verify the experimental measurements.
Auteurs: Ava J. Tan;Ajay K. Yadav;Korok Chatterjee;Daewoong Kwon;Sangwan Kim;Chenming Hu;Sayeef Salahuddin;
Apparue dans: IEEE Electron Device Letters
Date publication: 01.-2018, volume: 39, issue:1, pages: 95 - 98
Editeur: IEEE
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» A Noise Reconfigurable All-Digital Phase-Locked Loop Using a Switched Capacitor-Based Frequency-Locked Loop and a Noise Detector
Résumé:
Programmability is one of the most significant advantages of a digital phase-locked loop (PLL) compared with a charge-pump PLL. In this paper, a digital PLL that extends programmability to include noise is introduced. A digitally controlled oscillator (DCO) using a switched capacitor for frequency feedback is proposed to maintain a constant figure of merit while reconfiguring its noise performance. The proposed DCO offers an accurate and linear frequency tuning curve that is insensitive to environmental changes. A noise detection circuit using the statistical property of a bang-bang phase and frequency detector is proposed to autonomously adjust the output noise level depending on the noise specification. A prototype design is fabricated in a 28-nm FDSOI process. The integrated phase noise of the proposed PLL can be configured from 2.5 to 15 ps, while the power consumption ranges from 1.7 to 5 mW.
Auteurs: Taekwang Jang;Seokhyeon Jeong;Dongsuk Jeon;Kyojin David Choo;Dennis Sylvester;David Blaauw;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 01.-2018, volume: 53, issue:1, pages: 50 - 65
Editeur: IEEE
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» A Noise-Shaped Randomized Modulation for Switched-Mode DC-DC Converters
Résumé:
We propose a novel low-harmonics low-noise modulation scheme for switched-mode dc–dc converters. The proposed scheme is a hybrid of a randomized modulation scheme, namely, the randomized wrapped-around pulse position modulation scheme (RWAPPM), and a noise-shaper. The RWAPPM mitigates the switching-frequency harmonics in the input current, whereas the noise-shaper mitigates the low-frequency noise therein. We derive an analytical expression for the input current spectrum of the hybrid scheme. We benchmark the hybrid scheme against the conventional pulse width modulation scheme (PWM) and the RWAPPM without the noise-shaper. At 0.5 duty cycle, 3.3-V input voltage, 100-kHz average switching frequency, and with the second-order noise-shaper, the peak spectral power in the input current spectrum of the hybrid scheme is 18.1 dB lower than the PWM. Other randomized and spread-spectrum modulation schemes, in general, have undesirably higher input noise current than that of the PWM. However, the input noise current of the proposed hybrid scheme, obtained at ~73-mA rms (integrated over a 200-kHz bandwidth without an input filter), is comparable with that of the PWM, and is lower by ~16-mA rms compared with that of the RWAPPM without the noise-shaper. We also benchmark the hybrid scheme against other well known randomized and spread-spectrum modulation schemes. We further propose a novel pulse generator structure that embodies the hybrid scheme. We realize a dc–dc converter employing the pulse generator, and measure the converter to verify the derived expression and the characteristics of the hybrid scheme. We also measure the output voltage spectrum, the transient-response, and the operating range of the converter.
Auteurs: Keer Cui;Victor Adrian;Bah-Hwee Gwee;Joseph S. Chang;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 01.-2018, volume: 65, issue:1, pages: 394 - 405
Editeur: IEEE
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» A Noise-Tolerant Algorithm for Robot-Sensor Calibration Using a Planar Disk of Arbitrary 3-D Orientation
Résumé:
In a 3-D scanning task, a robot-sensor system controls a robotic arm to move a laser sensor. In order to align the coordinate system of the robotic arm and laser sensor, prior calibration is required to derive the transformation between both coordinate systems. This paper proposes a new calibration method in three steps: manual data collection, sensing data calculation, and transformation solution. First, at least four data are required to be collected by the user. The sensing data are then calculated from the collected data and adopted to provide the desired transformation. The proposed algorithm has two features: arbitrary placement of planar disk and noise tolerant. Using a planar disk, the algorithm will automatically derive the angular relationship between the disk and the sensor plane, enabling arbitrary orientation placement. Noise tolerant is guaranteed by fitting ellipses during the sensing data calculation and using a single set of sensing data in transformation solution. Experiments and comparisons are given to demonstrate the efficiency of the proposed calibration algorithm.

Note to Practitioners—This paper was motivated by the problem of calibrating a laser sensor and a positioning device (robot arm, CMM, etc.) in a robust and fast manner. Specifically, the calibration is to derive the transformation by aligning the sensors coordinate system to the positioning devices coordinate system. The proposed calibration procedure consists of two parts: manual data collection and automatic transformation calculation. During manual data collection, users only need to select four different data; whereby each data contains of two positions with the same orientation. Then, the desired transformation will be derived automatically. The calibration is designed in an efficient and robust way whereby: 1) data collection is done using a simple planar disk placed in arbitrary orientations; 2) minimum human i- teraction required; 3) tolerant to noise in the sensor data; and 4) easy implementation by following a proven and standard protocol.

Auteurs: Wenyu Chen;Jia Du;Wei Xiong;Yue Wang;Shueching Chia;Bingbing Liu;Jierong Cheng;Ying Gu;
Apparue dans: IEEE Transactions on Automation Science and Engineering
Date publication: 01.-2018, volume: 15, issue:1, pages: 251 - 263
Editeur: IEEE
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» A Novel 1-D Convolution Neural Network With SVM Architecture for Real-Time Detection Applications
Résumé:
To enhance the performance and sensitivity of continuous monitoring systems for detection of chronic diseases, selection of optimal machine learning algorithms is pivotal. Presently, the commonly used algorithms face constraints, such as high computational cost and lack of optimal feature selection on application to real time signals thereby reducing the efficiency of such analysis. Deep learning approaches, such as the convolution neural network, overcome these drawbacks by calculating automated features from raw signal and classifying the derived features. This architecture shows good merits. However, the use of fully connected multi-layer perceptron algorithms have shown low classification performance. This paper proposes to develop a modified deep learning convolution neural network algorithm integrated with support vector machines to address the drawbacks present in multi-layer perceptron and thereby improving the overall performance of real-time detection applications. The system is validated on real-time breath signals for non-invasive detection of diabetes. The performance of this proposed algorithm is evaluated and compared with the existing technique.
Auteurs: S. Lekha;M. Suchetha;
Apparue dans: IEEE Sensors Journal
Date publication: 01.-2018, volume: 18, issue:2, pages: 724 - 731
Editeur: IEEE
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» A Novel 2.6–6.4 GHz Highly Integrated Broadband GaN Power Amplifier
Résumé:
In this letter, a novel methodology to achieve output broadband matching is proposed. Based on this methodology, a broadband gallium nitride power amplifier (PA) with input matching and stabilization circuit integrated on-chip is designed. The implemented PA achieves a maximum drain efficiency of 62%–79.2% from 2.6 to 6.4 GHz (84.4% fractional bandwidth), with a saturated output power (Psat) of 34.3–35.8 dBm, while providing a gain larger than 10 dB. When tested with 802.11ac VHT80 MC9 (80 MHz, 256-QAM) with 11.3-dB peak-to-average power ratio, PA achieves a drain efficiency of 22.1%–25.2% with an average output power of 23–25.4 dBm across the whole band, while meeting the standard specification of error vector magnitude below −32 dB.
Auteurs: Bei Liu;Mengda Mao;Devrishi Khanna;Chirn-Chye Boon;Pilsoon Choi;Eugene A. Fitzgerald;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 37 - 39
Editeur: IEEE
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» A Novel 28 GHz Beam Steering Array for 5G Mobile Device With Metallic Casing Application
Résumé:
The design of a novel practical 28 GHz beam steering phased array antenna for future fifth generation mobile device applications is presented in this communication. The proposed array antenna has 16 cavity-backed slot antenna elements that are implemented via the metallic back casing of the mobile device, in which two eight-element phased arrays are built on the left- and right-side edges of the mobile device. Each eight-element phased array can yield beam steering at broadside and gain of >15 dBi can be achieved at boresight. The measured 10 dB return loss bandwidth of the proposed cavity-backed slot antenna element was approximately 27.5–30 GHz. In addition, the impacts of user’s hand effects are also investigated.
Auteurs: Bin Yu;Kang Yang;Chow-Yen-Desmond Sim;Guangli Yang;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 01.-2018, volume: 66, issue:1, pages: 462 - 466
Editeur: IEEE
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» A Novel Approach for Spectroscopic Chemical Identification Using Photonic Crystal Fiber in the Terahertz Regime
Résumé:
A novel highly sensitive porous core-photonic crystal fiber (PC-PCF) has been designed and analyzed for detection of chemical analytes in the terahertz frequency range. The PC-PCF is designed using rectangular structured air holes in the core with a kagome structured cladding. The full vectorial finite-element method is used to tune the geometrical parameters and to characterize the fiber. Our results demonstrate a high relative chemical sensitivity with significantly lower confinement loss for different analytes. Moreover, the PCF shows near zero dispersion variation, high modal effective area, high birefringence, and high numerical aperture. The practical realization of the fiber is feasible with present fabrication techniques. Our optimized PCF has commercial applications in chemical sensing as well as applications in terahertz systems that require guided polarization preserving transmission.
Auteurs: Md. Saiful Islam;Jakeya Sultana;Kawsar Ahmed;Mohammad Rakibul Islam;Alex Dinovitser;Brian Wai-Him Ng;Derek Abbott;
Apparue dans: IEEE Sensors Journal
Date publication: 01.-2018, volume: 18, issue:2, pages: 575 - 582
Editeur: IEEE
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» A Novel Approach of Fuzzy Dempster–Shafer Theory for Spatial Uncertainty Analysis and Accuracy Assessment of Object-Based Image Classification
Résumé:
Accuracy assessment is a fundamental step in remote-sensing image processing. The accuracy assessment techniques aim to compute classification accuracy and characterize errors, and can, thus, be used to refine the classification or estimates derived from the assessment itself. With regard to their technical capabilities, these techniques have been criticized for their inherent uncertainty and inability to evaluate image classification accuracies. To overcome this issue, the main objective of this letter was to introduce a new approach for the accuracy assessment of object-based image analysis (OBIA). To this end, an integrated approach of fuzzy synthetic evaluation and Dempster–Shafer theory (FSE-DST) was adapted and proposed as an effective approach for object-based image classification accuracy assessment. Two experiments were established to examine the capability of the proposed approach. OBIA was applied to develop a land-use land-cover map of Ahar city and the Ousko area. The proposed FSE-DST was applied for a spatially explicit accuracy assessment. Results indicate that FSE-DST can be effectively applied in spatial accuracy assessments for OBIA and for spatial accuracy assessments in remote-sensing-based classifications. The results of this letter are important to the development of OBIA and can serve as the basis for progressive research in remote sensing by supporting future researchers in obtaining more accurate results from OBIA-based classifications and spatially analyzing the reliability of results.
Auteurs: Bakhtiar Feizizadeh;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 01.-2018, volume: 15, issue:1, pages: 18 - 22
Editeur: IEEE
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» A Novel Approach to Improve the Performance of Charge Plasma Tunnel Field-Effect Transistor
Résumé:
A distinct approach is presented for realizing charge plasma tunnel field-effect transistor (CP TFET) wherein p+ substrate is taken as silicon film and then metal electrodes with specific work functions are deposited over the silicon film to accumulate n+ drain and intrinsic channel regions. This creates abruptness and reduces the barrier at the source/channel interface of CP TFET, which improves the dc characteristics of the device. Furthermore, the drain electrode is separated into two sections and applied with dual work function, which reduces the ambipolar behavior, parasitic capacitance, and enhances radio frequency parameters. The crux of the script is to advance the performance of the device while maintaining the classical CMOS fabrication flow with its inherent advantages by using p+ substrate initially. To analyze the performance, a comparison between conventional CP TFET and dual drain electrode CP TFET (proposed) is shown at the simulation level. Optimization of length and workfunction of the section of drain electrode adjacent to the channel is demonstrated to assess the desired ON-current and ambipolarity of the device. Furthermore, the device performance is examined with the application of multigate work function and heterogate dielectric engineering to achieve more improvements in device performance.
Auteurs: Sukeshni Tirkey;Dheeraj Sharma;Bhagwan Ram Raad;Dharmendra Singh Yadav;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 01.-2018, volume: 65, issue:1, pages: 282 - 289
Editeur: IEEE
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» A Novel Coupling Algorithm for Perfectly Matched Layer With Wave Equation-Based Discontinuous Galerkin Time-Domain Method
Résumé:
The second-order wave equation-based discontinuous Galerkin time-domain (DGTD) methods typically employ the first-order absorbing boundary condition for modeling open problems. To improve the modeling accuracy, this paper proposes a novel coupling algorithm of the well-posed perfectly matched layer (PML) for wave equation-based DGTD methods. Based on the domain decomposition technique, the proposed coupling algorithm divides the computational domain into two regions, that is, the physical and PML regions, whose meshes can be nonconformal with each other. Instead of introducing time convolution terms, the new coupling scheme is implemented through employing different DGTD frameworks for the two regions. Specifically, the physical region employs the wave equation-based DGTD framework, while the PML region employs the first-order Maxwell’s curl equations-based DGTD framework. To facilitate modeling of electrically small problems, the implicit Newmark-beta time integration is used for the physical region. To conveniently couple with the physical region, the implicit Crank–Nicolson algorithm is used for the PML region. Numerical results are shown to examine the accuracy and efficiency of the proposed coupling algorithm for modeling electrically small problems.
Auteurs: Qingtao Sun;Runren Zhang;Qiwei Zhan;Qing Huo Liu;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 01.-2018, volume: 66, issue:1, pages: 255 - 261
Editeur: IEEE
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» A Novel Design of Dual-Band Rat-Race Coupler With Reconfigurable Power-Dividing Ratio
Résumé:
This letter presents, for the first time, the design of a reconfigurable rat-race coupler with dual-band operation. This device can offer power-dividing ratio of $K^{2}$ or $infty $ at two different frequency bands. The proposed design also features low insertion loss, high port isolation, compact size, single control voltage, and minimal number of RF switches. For demonstration, both simulation and measured results of a 0.9-/2-GHz reconfigurable rat-race coupler implemented on microstrip are given.
Auteurs: Li-Peng Cai;Kwok-Keung M. Cheng;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 01.-2018, volume: 28, issue:1, pages: 16 - 18
Editeur: IEEE
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» A Novel Extended State Observer for Output Tracking of MIMO Systems With Mismatched Uncertainty
Résumé:
In this paper, we develop a novel extended state observer (ESO), in terms of tracking error only, for output tracking of a class of multi-input multioutput systems with mismatched uncertainty. A novel ESO is constructed from the nonsmooth function “$text{fal}$ ” to estimate both uncertainty and state of the system. An ESO-based output feedback controller is then designed to compensate (cancel) the uncertainty and to achieve the output tracking. The convergence of the closed-loop system is proved. The effectiveness of the proposed method is demonstrated by numerical results of trajectory tracking for a practical autonomous underwater vehicle model. We show that in the presence of measurement noise, this novel ESO leads to better performance than the linear ESO. Moreover, this type of ESO has much smaller peaking value than the linear ESO under the same tuning gain.
Auteurs: Zhi-Liang Zhao;Bao-Zhu Guo;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 01.-2018, volume: 63, issue:1, pages: 211 - 218
Editeur: IEEE
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» A Novel Fully Analog Null Instrument for Resistive Wheatstone Bridge With a Single Resistive Sensor
Résumé:
When high-speed measurements are not necessary, the Wheatstone bridge-based null measurement instruments surpass the Wheatstone Bridge-based instruments using deflection technique, due to the fact that the null method has some intrinsic advantages over the deflection method. In this particle, a fully analog method has been introduced in order to implement a null measurement instrument for a resistive Wheatstone bridge with a single resistive sensor. In order to implement the proposed circuit, only two operational amplifiers and some passive elements have been used. The proposed method can be constructed and implemented by discrete components without any special limitation. Since the suggested scheme has linear output, the required computation in order to measure and display the measurand is reduced dramatically. Finally, in order to evaluate the performance and usefulness of the proposed method, it has been tested experimentally as well as by using computer aided design software.
Auteurs: Emad Alnasser;
Apparue dans: IEEE Sensors Journal
Date publication: 01.-2018, volume: 18, issue:2, pages: 635 - 640
Editeur: IEEE
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