ABCelectronique : portail d'information dans le domaine de l'électronique
Pages: 0123456789101112


Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 11-2017 trié par par titre, page: 0
» $epsilon $ -Almost Selectors and Their Applications to Multiple-Access Communication
Résumé:
Consider a group of stations connected through a multiple-access channel, with the constraint that if at a time instant exactly one station transmits a message, then the message is successfully received by any other station, whereas if two or more stations simultaneously transmit their messages then a conflict occurs and all messages are lost. Let us assume that $n$ is the number of stations and that an (arbitrary) subset $A$ of them, $|A|leq kleq n$ , is active, that is, there are at most $k$ stations that have a message to send over the channel. In the classical conflict resolution problem, the issue is to schedule the transmissions of each station to let every active station use the channel alone (i.e., without conflict) at least once, and this requirement must be satisfied whatever might be the set of active stations $A$ . The parameter to optimize is, usually, the worst case number of transmissions that any station has to attempt before all message transmissions are successful. In this paper, we study the following question: is it possible to obtain a significant improvement on the protocols that solve the classical conflict resolution problem if we allow the protocols to fail over a “small” fraction of all possible subsets of active stations? In other words, is it possible to significantly reduce the number of transmissions that must be attempted if the set of active stations is chosen uniformly at random and the conflict resolution algorithm is only required to work correctly with “high” prob- bility? In this paper, we will show that this is indeed the case. Our main technical tool is a generalization of selectors, a recently introduced combinatorial structure that has found applications in several areas. As it turned out for selectors, we believe that our new combinatorial structures are likely to be useful also outside the present context.
Auteurs: Annalisa De Bonis;Ugo Vaccaro;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 11.-2017, volume: 63, issue:11, pages: 7304 - 7319
Editeur: IEEE
Document complet vers site de l'éditeur
 
» ${mathcal{H}}_2$ State Feedback Control Design of Continuous-Time Positive Linear Systems
Résumé:
This technical note focuses on state feedback control design of positive linear systems in continuous-time domain. The main goal is to analyze stability and performance preserving the closed-loop system positivity. In some sense, the provided results fill the literature gap by considering the ${mathcal{H}}_2$ performance index. Indeed, although ${mathcal{H}}_infty$ state feedback control design of positive systems has received remarkable attention in the recent years, we believe that, for the first time, a numerical method able to provide a local optimal solution to this class of nonconvex control problems is addressed by means of a simple (since no line search is required) convergent sequence of convex programming problems. The theory and the algorithm behavior are illustrated and evaluated by numerical examples borrowed from the recent literature.
Auteurs: Grace S. Deaecto;José C. Geromel;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 11.-2017, volume: 62, issue:11, pages: 5844 - 5849
Editeur: IEEE
Document complet vers site de l'éditeur
 
» “Pseudo” Direct Drive Electrical Machines With Alternative Winding Configurations
Résumé:
The integration of a magnetic gear and a brushless permanent magnet machine to realize a “pseudo” direct drive (PDD) with alternative winding configurations is investigated. It is shown topologies which facilitate the winding process and achieve a more robust stator construction exist. Comparisons with conventional PDD topologies which are essentially equipped with concentric windings have shown that similar efficiencies can be achieved, albeit at the expense of reduced torque densities. Furthermore, analysis of the magnetic forces exhibited by a pole piece has shown that both the average and dynamic forces are significantly affected by the rated load condition, exacerbating the radial forces.
Auteurs: Glynn Cooke;Kais Atallah;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 8
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 1.06 FoM and Compact Wireless Power Transfer System Using Rectangular Defected Ground Structure Resonators
Résumé:
This letter proposes a wireless power transfer (WPT) system using coplanar waveguide fed rectangular defected ground structure (DGS) resonators. One of the advantages of rectangular DGS resonator is that it has higher quality (Q-) and coupling (K-) factor compared to the H-shape or semi-H-shape DGS resonators. When two DGS resonators are coupled back-to-back, it transforms to a bandpass filter with tight coupling, resulting in the transfer of power wirelessly. The fabricated WPT system of size $35.8~text {mm} times 20$ mm achieves, for the first time, a figure of merit of more than one at a WPT distance from 40 to 44 mm.
Auteurs: F. Tahar;R. Saad;A. Barakat;R. K. Pokharel;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 11.-2017, volume: 27, issue:11, pages: 1025 - 1027
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 2-D Optimization Methodology for Reconfigurable Transmitters by Tunable Matching Networks
Résumé:
Since the complexity of a reconfigurable transmitter architecture increases with the number of variable parameters, a methodology to optimize architectures based on discrete reconfigurable matching networks (RMNs) is presented. A design with two RMNs and a stabilized power transistor is used to test the proposed algorithm. A band-reconfigurable efficiency-optimized power amplifier (PA) and a frequency-tunable driver amplifier are reported using the same topology and transistor under various bias. Referred to a fixed approach, not only the efficiency of the PA is improved (46.73% at 410 MHz and 45.72% at 600 MHz) but also the gain and the matching of the driver.
Auteurs: Jose-Ramon Perez-Cisneros;Jesus de Mingo;Pedro L. Carro;Paloma Garcia-Ducar;Carlos Mateo;Antonio Valdovinos;César Sánchez-Pérez;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 11.-2017, volume: 64, issue:11, pages: 1277 - 1281
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 2-D Semi-Analytical Modeling of Eddy Currents in Multiple Non-Connected Conducting Elements
Résumé:
This paper concerns the semi-analytical modeling of parasitic eddy current distributions and forces in electromagnetic devices. The harmonic, Fourier-based, model is extended to incorporate a position-dependent conductivity, and restrictions on the induced current density are added to model eddy currents in non-connected conducting elements. To model time-dependent behavior of eddy currents, multiple time harmonics can be incorporated in the solutions. The developed method is verified using the finite-element method for a wide range of frequencies. The model is applied to a coreless linear motor with electrically conducting cooling plates, and the parasitic force is analyzed.
Auteurs: C. H. H. M. Custers;J. W. Jansen;E. A. Lomonova;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 6
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 3-D Absorptive Frequency Selective Reflector for Antenna Radar Cross Section Reduction
Résumé:
A methodology for designing a frequency selective reflector with two-sided absorption bands is proposed. This method is based on utilizing multimode resonators inside a 3-D unit cell to obtain an absorption-reflection-absorption response. Detailed analysis of this 3-D absorptive frequency selective reflector (AFSR) is provided with the aid of an equivalent circuit model to reveal the operating principle. To show the benefit of the new structure in antenna’s radar cross section reduction (RCSR), a dual-polarized 3-D-AFSR integrated with monopole and dipole antennas are simulated, fabricated, and then measured. Compared with their counterparts with normal ground plane, AFSR-backed antennas have shown a remarkable out-of-band RCSR. The −10 dB RCSR has fractional bandwidths of at least 64.7% and 41% with center frequencies of 3.4 and 8.3 GHz, respectively. The radiation characteristics of AFSR-backed antennas are nearly maintained. The realized gains are enhanced by 0.9 and 2.3 dB for monopole and dipole antennas mounted on a 3-D-AFSR, respectively.
Auteurs: Hao Huang;Zhongxiang Shen;Ahmed Abdelmottaleb Omar;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 5908 - 5917
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 3-D Active Contour Segmentation Based on Sparse Linear Combination of Training Shapes (SCoTS)
Résumé:
SCoTS captures a sparse representation of shapes in an input image through a linear span of previously delineated shapes in a training repository. The model updates shape prior over level set iterations and captures variabilities in shapes by a sparse combination of the training data. The level set evolution is therefore driven by a data term as well as a term capturing valid prior shapes. During evolution, the shape prior influence is adjusted based on shape reconstruction, with the assigned weight determined from the degree of sparsity of the representation. For the problem of lung nodule segmentation in X-ray CT, SCoTS offers a unified framework, capable of segmenting nodules of all types. Experimental validations are demonstrated on 542 3-D lung nodule images from the LIDC-IDRI database. Despite its generality, SCoTS is competitive with domain specific state of the art methods for lung nodule segmentation.
Auteurs: M. Mehdi Farhangi;Hichem Frigui;Albert Seow;Amir A. Amini;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 11.-2017, volume: 36, issue:11, pages: 2239 - 2249
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 3-D Coverage Beam-Scanning Antenna Using Feed Array and Active Frequency-Selective Surface
Résumé:
This paper presents the design of a smart antenna that can achieve 3-D beam-scanning coverage. The antenna consists of a novel planar feed array and a cylindrical active frequency-selective surface (AFSS). First, an array fed metallic reflector is studied as a reference antenna to validate the beam-scanning characteristics in the elevation plane. Then, the AFSS is assessed through simulation and measurement results. Finally, the complete structure containing the planar collinear array and the AFSS is analyzed. A prototype at S-band has been designed, manufactured, and measured. The resulting antenna is shown to be able to operate at the 2.4–2.5 GHz frequency band and switch beams in both the azimuth and elevation planes. In the azimuth plane, the proposed antenna is capable of sweeping beams toward different directions to cover a full range of 360°. In the elevation plane, it can achieve beam steering within an angle range of +16°/ − 15°. The measured maximum gain of the antenna is 9.2 dBi. This is the first report of a low-cost 3-D coverage beam-scanning antenna based on AFSS.
Auteurs: Chao Gu;Steven Gao;Benito Sanz-Izquierdo;Edward A. Parker;Fan Qin;Hang Xu;John C. Batchelor;Xuexia Yang;Zhiqun Cheng;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 5862 - 5870
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 3-D Integral Approach for Calculating Mutual Interactions Between Polygon-Shaped Massive Coils
Résumé:
The 3-D analytical calculations are proposed using Green’s function (integral approach) for determining magnetic flux densities, mutual inductances, or interaction energies and magnetic force components between different polygon-shaped coils with a rectangular cross section. The basic concept is the determination of the cited magnetic quantities from elementary linear conductors with arbitrary orientations in desired planes. The process is described by using the space transformation matrices of the different axes in which the conductors have previously been defined. The developed results are validated by comparison with those issued from 3-D finite-element methods (Flux 3-D Software). The calculated mutual inductances for some applications are also compared with realized experimental measures.
Auteurs: L. Aomar;H. Allag;M. Feliachi;J. -P. Yonnet;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 5
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 3-D Interconnected Magnetic Nanofiber Networks With Multifunctional Properties
Résumé:
3-D alloyed and multilayered interconnected nanofiber networks have been fabricated by electrodeposition techniques, allowing a controlled composition and 3-D structural topology. These features have been found crucial to tailor their magnetic and magneto-transport properties. Their interplay along with the use of a simple analytical model based on the particular interconnected topology of the networks has allowed to accurately determine the anisotropic magnetoresistance (AMR) ratio. The as-obtained AMR ratio for interconnected nanofiber networks is consistent with an average that results from all the nanowires orientations in the membrane. The careful choice of magnetic and non-magnetic layer thicknesses has been decisive for the fabrication of Co/Cu multilayered interconnected nanofiber networks with giant magnetoresistive response as high as 19%. Interconnected nanofiber networks with controlled material composition and specific structural features are very attractive for the development of mechanically stable superstructures suitable for potential technological device applications.
Auteurs: Tristan da Câmara Santa Clara Gomes;Joaquín De La Torre Medina;Yenni G. Velázquez-Galván;Juan M. Martínez-Huerta;Armando Encinas;Luc Piraux;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 6
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 3-D New Calculation Principle of Levitation Force Between Permanent Magnet and Hard Type-II Superconductor Using Integral Approach
Résumé:
A new contribution is given for the calculation of interaction forces between the permanent magnet (PM) and a hard type-II superconductor (SC) used as a classical levitation system. The forces and also mutual inductances are developed via Green’s functions using an Amperian model, assuming a cuboidal thin coil for PM and a superposition of closed loops of rectangular cross section of the SC. In the superconductor, the critical current ( $J_{c})$ is known, but the variable penetration thickness of $J_{c}$ is given from external magnetic fields by Bean’s critical-state models. All the analytical results are obtained with a dynamic representation of all penetration thicknesses of $J_{c}$ depending on applied external magnetic field variations. The most important parts are the original mathematical process of considering current penetration in superconductors and the new analytical development of vertical forces between PM and SC, realized after several analytical integral calculations. The results have been evaluated for vertical displacements of a PM above the SC, proving the accuracy of our analytical model compared with those realized by Flux3D finite-element method software.
Auteurs: A. Azzouza;H. Allag;J. -P. Yonnet;P. Tixador;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 5
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 4 tough chemistry problems that quantum computers will solve [News]
Résumé:
Someday, engineers will design large quantum computers that can solve seemingly impossible science problems, crack unbreakable encryption, and make artificial intelligence smarter. In the meantime, the companies now building quantum computers are trying to figure out how to use the small ones they expect to produce in the coming years. One field in which the first generation of quantum computers may be able to make headway is chemistry. Theoretical work suggests that such computers—perhaps even relatively small ones—will eventually be able to solve important problems in chemistry that are intractable on existing computers.
Auteurs: Katherine Bourzac;
Apparue dans: IEEE Spectrum
Date publication: 11.-2017, volume: 54, issue:11, pages: 7 - 9
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 4H-SiC Trench MOSFET With Floating/Grounded Junction Barrier-controlled Gate Structure
Résumé:
A novel silicon carbide (SiC) trench MOSFET with floating/grounded junction barrier-controlled gate structure (FJB-MOS/GJB-MOS) is presented and investigated utilizing Sentaurus TCAD simulations. The split P+ region introduced beneath the trench could better shield the gate oxide from the high electric field in the blocking mode, leading to an enhancement in the breakdown voltage while without significant degradation of other characteristics. As a result, the FJB-MOS with floating P+ shielding exhibits a higher figure of merit related to the breakdown voltage and the specific on-resistance ( ${V}_{textsf {BR}}^{{,textsf {2}}}/{R}_{ mathrm{scriptscriptstyle ON},textsf {sp}}$ ), which is improved by 15% and 49%, respectively, with comparison to those of the state-of-the-art double-trench MOSFET and L-shaped gate trench MOSFET. In terms of the GJB-MOS with grounded P+ shielding, it shows great advantage in reducing the switching losses thanks to the lower specific gate–drain charge ${Q}_{{:textsf {gd,sp}}}$ and is more conductive to high frequency applications. Additionally, the formation of the P+ region is aided by the Sentaurus Process and the processing implementation of the proposed structure is discussed.
Auteurs: Xintian Zhou;Ruifeng Yue;Jian Zhang;Gang Dai;Juntao Li;Yan Wang;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 11.-2017, volume: 64, issue:11, pages: 4568 - 4574
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 5G Uniform Linear Arrays With Beamforming and Spatial Multiplexing at 28, 37, 64, and 71 GHz for Outdoor Urban Communication: A Two-Level Approach
Résumé:
Multiple-input multiple-output (MIMO) spatial multiplexing and beamforming are regarded as key technology enablers for the fifth-generation (5G) millimeter wave (mmWave) mobile radio services. Spatial multiplexing requires sufficiently separated and incoherent antenna array elements, while in the case of beamforming, the antenna array elements need to be coherent and closely spaced. Extensive 28-, 60-, and 73-GHz ultra-wideband propagation measurements in cities of New York City and Austin have indicated formation of two or more spatial lobes for the angles-of-departure and angles-of-arrival even for line-of-sight (LOS) transmission, which is an advantageous feature of mmWave channels, indicating that the transmitting and receiving array antenna elements can be co-located, thus enabling a single architecture for both spatial multiplexing and beamforming. In this paper, a two-level beamforming architecture for uniform linear arrays is proposed that leverages the formation of these spatial lobes. The antenna array is composed of sub-arrays, and the impact of sub-array spacing on the spectral efficiency is investigated through simulations using a channel simulator named NYUSIM developed based on extensive measured data at mmWave frequencies. Simulation results indicate spectral efficiencies of 18.5–28.1 bits/s/Hz with a sub-array spacing of 16 wavelengths for an outdoor mmWave urban LOS channel. The spectral efficiencies obtained are for single-user (SU) MIMO transmission at the recently allocated 5G carrier frequencies in July 2016. The method and results in this paper are useful for designing antenna array architectures for 5G wireless systems.
Auteurs: Jaswinder Lota;Shu Sun;Theodore S. Rappaport;Andreas Demosthenous;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 11.-2017, volume: 66, issue:11, pages: 9972 - 9985
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 64-QAM 60-GHz CMOS Transceivers for IEEE 802.11ad/ay
Résumé:
This paper presents 64-quadrature amplitude modulation (QAM) 60-GHz CMOS transceivers with four-channel bonding capability, which can be categorized into a one-stream transceiver and a two-stream frequency-interleaved (FI) transceiver. The transceivers are both fabricated in a standard 65-nm CMOS technology. For the proposed one-stream transceiver, the TX-to-RX error vector magnitude (EVM) is less than −23.9 dB for 64-QAM wireless communication in all four channels defined in the IEEE 802.11ad/WiGig. The maximum communication distance with the full rate can reach 0.13 m for 64 QAM, 0.8 m for 16 QAM, and 2.6 m for QPSK using 14-dBi horn antennas. A data rate of 28.16 Gb/s is achieved in 16 QAM by four-channel bonding. The transmitter, receiver, and phase-locked loop consume 186, 155, and 64 mW, respectively. The core area of the transceiver is 3.9 mm2. For the proposed two-stream FI transceiver, four-channel bonding in 64 QAM is realized with a data rate of 42.24 Gb/s and an EVM of less than −23 dB. The front end consumes 544 mW in transmitting mode and 432 mW in receiving mode from a 1.2-V supply. The core area of the transceiver is 7.2 mm2.
Auteurs: Rui Wu;Ryo Minami;Yuuki Tsukui;Seitaro Kawai;Yuuki Seo;Shinji Sato;Kento Kimura;Satoshi Kondo;Tomohiro Ueno;Nurul Fajri;Shoutarou Maki;Noriaki Nagashima;Yasuaki Takeuchi;Tatsuya Yamaguchi;Ahmed Musa;Korkut Kaan Tokgoz;Teerachot Siriburanon;Bangan Liu
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 2871 - 2891
Editeur: IEEE
Document complet vers site de l'éditeur
 
» 94 GHz Substrate Integrated Waveguide Dual-Circular-Polarization Shared-Aperture Parallel-Plate Long-Slot Array Antenna With Low Sidelobe Level
Résumé:
In this paper, a 94 GHz substrate integrated waveguide (SIW) parallel-plate long-slot array antenna is presented, which is able to generate dual-circular-polarization (CP) low sidelobe level (SLL) beams from a single radiating aperture. This antenna consists of two layers of substrates. One is used to construct the unequal feeding network and the other is used to construct a $15 times 15$ shared-aperture parallel-plate long-slot array antenna. This multilayer topology has a smaller size compared with the single-layer design. A simple and feasible method is applied to control the radiation pattern, which is able to realize dual-CP low SLL beams without a complicated feeding network. Two 1-D sixteen-way unequal dividers are employed to suppress the SLL in two planes of a CP array. Then, a 90° coupler is employed in the feeding network to switch the polarization modes between left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). Finally, a prototype of SIW parallel-plate long-slot array antenna is fabricated. Simulation and measured results show that SLLs of the fabricated antenna are under −18.5 dB in two planes.
Auteurs: Yu Jian Cheng;Jun Wang;Xiao Liang Liu;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 5855 - 5861
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A +25-dBm IIP3 1.7–2.1-GHz FDD Receiver Front End With Integrated Hybrid Transformer in 28-nm CMOS
Résumé:
A highly linear receiver (RX) front end with integrated hybrid transformer (HT) for frequency-division duplexing mobile communications is reported. The HT, implemented with a three-winding coplanar transformer, is used to interface the RX front end with the antenna and the power amplifier. The primary is driven at its center tap with the transmitted signal and at one input with the antenna signal, while the other input is connected to an on-chip programmable balancing impedance. The two secondary drives a differential push–pull common-gate low-noise amplifier (LNA). Assuming a perfectly linear hybrid only 45 dB of transmitter (TX)–RX isolation and 35 dB of common-mode rejection are required to meet the intermodulation specs thanks to the +25-dBm receiver IIP3. This would drastically simplify hybrid balancing and adaptation loop. Cascaded noise figure of duplexer, LNA, and baseband is below 6.7 dB and TX insertion loss below 4.3 dB from 1.7 to 2.1 GHz. The implemented prototype in 28-nm CMOS has an active area of 0.7 mm2 and requires only 26 mW.
Auteurs: Ivan Fabiano;Matteo Ramella;Danilo Manstretta;Rinaldo Castello;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 11.-2017, volume: 65, issue:11, pages: 4677 - 4688
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 0.31-pJ/bit 20-Gb/s DFE With 1 Discrete Tap and 2 IIR Filters Feedback in 40-nm-LP CMOS
Résumé:
This brief presents a low-power 20-Gb/s decision feedback equalizer (DFE) with one discrete tap and two infinite impulse response (IIR) filters feedback. The advantage of the IIR-DFE lies in both great energy and area efficiency for large channel attenuations. To further enhance the power efficiency of the IIR-DFE, the charge-steering logic (CSL) is utilized in this brief. Besides, the quarter-rate topology is adopted to alleviate the race condition of the CSL-based DFE. Fabricated in a 40-nm-LP CMOS process, the DFE core circuits only consumes 6.2 mW from the 1-V supply. Moreover, the core entirely occupies an area of 5700 $mu {mathrm{ m}}^{2}$ . Measured with PRBS7, the bit error rates are all less than $10^{-12}$ for channel loss from −7.98 to −18.3 dB. Finally, the power efficiency of this IIR-DFE is 0.31 pJ/bit.
Auteurs: Kuan-Yu Chen;Wei-Yung Chen;Shen-Iuan Liu;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 11.-2017, volume: 64, issue:11, pages: 1282 - 1286
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 0.8–1.2 V 10–50 MS/s 13-bit Subranging Pipelined-SAR ADC Using a Temperature-Insensitive Time-Based Amplifier
Résumé:
This paper presents an energy-efficient 13-bit 10–50 MS/s subranging pipelined-successive approximation register (SAR) analog-to-digital converter (ADC) with power supply scaling. In the presented ADC, an SAR-assisted subranging floating capacitive DAC switching algorithm reduces switching energy along with enhanced linearity and speed in the first-stage SAR ADC. A following temperature-insensitive time-based residue amplifier realizes open-loop residual amplification without background calibration, while maintaining the benefits of dynamic operation and noise filtering. Furthermore, asynchronous SAR control logic employs a pre-window technique to accelerate SAR logic operations. The prototype ADC was fabricated in a 130-nm CMOS process with an active area of 0.22 mm2. With a 1.2-V power supply and a Nyquist frequency input, the ADC consumes 1.32 mW at 50 MS/s and achieves signal-to-noise and distortion ratio and spurious-free dynamic range of 69.1 and 80.7 dB, respectively. The operating speed is scalable from 10 to 50 MS/s with a scalable power supply range of 0.8–1.2 V. Walden FoMs of 4–11.3 fJ/conversion-step are achieved.
Auteurs: Minglei Zhang;Kyoohyun Noh;Xiaohua Fan;Edgar Sánchez-Sinencio;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 2991 - 3005
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 0.9–2.6 GHz Cognitive Radio Receiver With Spread Spectrum Frequency Synthesizer for Spectrum Sensing
Résumé:
In this paper, 0.9–2.6 GHz receiver with spread spectrum frequency synthesizer is proposed for spectrum sensing cognitive radio system. With the presence of spread spectrum window generated by local synthesizer, the bandwidth of low-pass filter for spectrum sensing can be fixed, which alleviates the complexity of energy detection block, making it easily embedded into a transceiver chip. The proposed coherent sampling quickens energy detection under negative signal-to-noise ratio. The proposed direct conversion receiver with wideband interference rejection includes a low noise amplifier and mixer, which achieves a NF of 5 dB and gain of 30 dB over the entire bandwidth with 20 mW power consumption. The ultra-wideband voltage controlled oscillator with loss compensation is designed to cover 0.9–2.6 GHz. A prototype chip has been fabricated in $0.18~mu text{m}$ CMOS technology consuming 130 mW in sensing mode with 1.8 V power supply. The total chip area including pads is approximately 2.75 mm2. The proposed CR receiver achieves wide operation frequency range from 900 MHz to 2.6 GHz with minimum detection sensitivity of −93.2 dBm and adjustable detection window of 35~70 MHz.
Auteurs: Lei Qiu;Supeng Liu;Ying Zhang;Yao Zhu;Kai Tang;Yuanjin Zheng;
Apparue dans: IEEE Sensors Journal
Date publication: 11.-2017, volume: 17, issue:22, pages: 7569 - 7577
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 1.4-m $Omega$ -Sensitivity 94-dB Dynamic-Range Electrical Impedance Tomography SoC and 48-Channel Hub-SoC for 3-D Lung Ventilation Monitoring System
Résumé:
A wearable electrical impedance tomography (EIT) system is proposed for the portable real-time 3-D lung ventilation monitoring. It consists of two types of SoCs, active electrode (AE)-SoC and Hub-SoC, mounted on wearable belts. The 48-channel AE-SoCs are integrated on flexible printed circuit board belt, and Hub-SoC is integrated in the hub module which performs data gathering and wireless communication between an external imaging device. To get high accuracy under the variation of conductivity, the dual-mode current stimulator provides the optimal frequency for time difference-EIT and frequency difference-EIT with simultaneous 4 k–128 kHz impedance sensing. A wide dynamic range instruments amplifier is proposed to provide 94 dB of wide dynamic range impedance sensing. In addition, the 48-channel AE system with the dedicated communication and calibration is implemented to achieve 1.4- $text{m}Omega $ sensitivity of impedance difference in the in vivo environment. The AE-/Hub-SoCs occupy 3.2 and 1.3 mm2 in 65-nm CMOS technology and consume $124~mu text{W}$ and 1.1 mW with 1.2 V supply, respectively. As a result, EIT images are reconstructed with 90% of accuracy, and up to 10 frames/s real-time 3-D lung images are successfully displayed.
Auteurs: Minseo Kim;Jaeeun Jang;Hyunki Kim;Jihee Lee;Jaehyuck Lee;Jiwon Lee;Kyoung-Rog Lee;Kwantae Kim;Yongsu Lee;Kyuho Jason Lee;Hoi-Jun Yoo;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 2829 - 2842
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 10-Mb/s Uplink Utilizing Rectifier Third-Order Intermodulation in a Miniature CMOS Tag
Résumé:
This letter introduces an inductive power transfer (IPT) uplink to a miniature CMOS tag. The transmitter (Tx) sends a two-tone waveform at 5.728/5.768 GHz to charge the tag and excites a third-order intermodulation frequency at 5.808 GHz from the tag rectifier, which is then modulated and returned to the reader receiver (Rx) via the same coupled coils used for the IPT. The Tx/Rx frequency separation, incorporating an appropriate duplexer, allows significant filtering on the Tx-to-Rx leakages. The achieved uplink data rate is 10 Mb/s.
Auteurs: Nai-Chung Kuo;Bo Zhao;Ali M. Niknejad;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 11.-2017, volume: 27, issue:11, pages: 1031 - 1033
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 144-MHz Fully Integrated Resonant Regulating Rectifier With Hybrid Pulse Modulation for mm-Sized Implants
Résumé:
This paper presents a fully integrated resonant regulating rectifier (IR3) with an on-chip coil used to wirelessly power mm-sized implants. By combining rectification and regulation in a single stage, and controlling this stage via a hybrid pulse-width modulation and pulse-frequency modulation (PFM) feedback scheme, the IR3 avoids efficiency-limiting cascaded losses while enabling tight voltage regulation with low dropout and ripple. The IR3 is implemented in 0.078 mm2 of active area in 180-nm Silicon oxide insulator (SOI) CMOS, and achieves a 1.87% $Delta V_{{{textrm{DD}}}}/V_{{{textrm{DD}}}}$ power supply regulation ratio with a 1-nF decoupling capacitor despite a tenfold load current variation from 8 to 80 $mu {{text{A}}}$ . A 0.8-V $V_{{{textrm{DD}}}}$ is maintained at a 8- ${{text{k}}}Omega $ load for 144-MHz RF inputs ranging from 0.98 to 1.5 V. At 1-V regulation, the voltage conversion efficiency is greater than 92% with less than 5.2- ${{text{m}}}V_{{{textrm{pp}}}}$ ripple, while the power conversion efficiency is 54%. The measured overall wireless power transfer system efficiency, from the primary coil to $V_{{{textrm{DD}}}}$ output of the IR3, is 2% at 160- $mu {{text{W}}}$ load, and reaches 5% at 700 $mu {{text{W}}}$ .
Auteurs: Chul Kim;Sohmyung Ha;Jiwoong Park;Abraham Akinin;Patrick P. Mercier;Gert Cauwenberghs;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 3043 - 3055
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 15-V Bidirectional Current Clamp Circuit for Integrated Patch Clamp Electrophysiology
Résumé:
This brief presents a high-voltage low-noise current clamp circuit for patch clamp electrophysiology systems. The circuit includes a novel programmable bidirectional current source spanning a pA to nA range, while supporting an 11.1-V input voltage range and being insensitive to opamp offset voltage. The measured output current noise floor is $8.0,,text{fA}/boldsymbol {sqrt {mathrm {Hz}}}$ while sourcing 100 pA. For a measurement bandwidth of 1 kHz, the corresponding integrated noise current is 588 fARMS. The system occupies an area of 0.2 mm2 in 180-nm CMOS and consumes 4 mA from a 15-V supply.
Auteurs: Shanshan Dai;Jacob K. Rosenstein;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 11.-2017, volume: 64, issue:11, pages: 1287 - 1291
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 2-D FDTD Model for Analysis of Plane Wave Propagation Through the Reentry Plasma Sheath
Résumé:
A 2-D finite-difference time domain model was developed to analyze the wideband plane wave propagation characteristics in the reentry plasma sheath at the receiving antenna position. Because of the variation of the flow field, various inhomogeneous structures exist in the plasma sheath, such as electron density irregularities, large-scale ablation particles, and vortex electron density structures, which play important roles in refracting and distorting the electromagnetic wave signals. The proposed model directly included the effects of these inhomogeneous structures. The model used a $pi $ -shaped total-field/scattered-field (TF/SF) boundary to introduce the plane wave source to the simulation domain. Based on the current density convolution (JEC) method and the phase matching principle, six 1-D auxiliary propagators were generated to obtain field values at the TF/SF boundary. The convolutional perfectly matched layer was implemented as the absorbing boundary condition of the auxiliary propagator. The efficiency and accuracy of the proposed method were validated by numerical examples.
Auteurs: Yang Zhang;Yanming Liu;Xiaoping Li;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 5940 - 5948
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 2-D Space-Variant Motion Estimation and Compensation Method for Ultrahigh-Resolution Airborne Stepped-Frequency SAR With Long Integration Time
Résumé:
For the ultrahigh-resolution airborne stepped-frequency synthetic aperture radar, very large synthetic bandwidth and very long integration time may lead to a 2-D space-variant (SV) motion error when the aircraft flies off the ideally straight trajectory due to the atmospheric turbulence. This new type of error complicates the motion estimation and motion compensation (MOCO). For the motion estimation, we present a jointly 2-D SV motion error estimation method to simultaneously consider the range-variant motion error and the azimuth-variant motion error. For the MOCO, we propose a 2-D SV-MOCO method. The method is implemented through three processing steps: 1) two-step MOCO for the space-invariant motion error and the range-variant phase error; 2) range block-based chirp-z transform (CZT) for the range-variant envelope error; and 3) range block division for the range-dependent azimuth-variant phase error based on the azimuth subaperture method. Finally, processing of simulated data and real data validates the proposed methods.
Auteurs: Jianlai Chen;Mengdao Xing;Guang-Cai Sun;Zhenyu Li;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 11.-2017, volume: 55, issue:11, pages: 6390 - 6401
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 2.4-GHz 1.5-mW Digital Multiplying Delay-Locked Loop Using Pulsewidth Comparator and Double Injection Technique
Résumé:
In this paper, we propose a low-jitter low-power digital multiplying delay-locked loop (MDLL) with a self-calibrated double reference injection scheme. To reduce jitter, the noisy edge of the oscillator is replaced by both the rising and falling edges of the clean reference, which results in 6-dB reduction in phase noise compared with a conventional single-edge injection MDLL. Reference spur caused by a frequency error of the oscillator, duty-cycle error of the reference, and circuit imperfection, such as offset and mismatch, is removed by employing three background feedback loops with a shared analog pulsewidth comparator. Implemented in 28-nm CMOS, the proposed digital MDLL generates 2.4-GHz clock and achieves a spur of −51.4 dBc and an rms jitter of 699 ${mathrm{ fs}}_{mathrm{ rms}}$ while consuming 1.5 mW from 1-V supply.
Auteurs: Hyunik Kim;Yongjo Kim;Taeik Kim;Hyung-Jong Ko;Seonghwan Cho;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 2934 - 2946
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 2.4-GHz Ternary Sequence Spread Spectrum OOK Transceiver for Reliable and Ultra-Low Power Sensor Network Applications
Résumé:
The ON/OFF keying (OOK) transmitter is re-investigated to utilize its structural simplicity and low power features for the reliable, ultra-low power sensor network applications. A novel architecture of 2.4-GHz ternary sequence spread spectrum (TSSS) OOK transceiver with spreading gain, spur suppression, and dual-mode detection techniques is presented. A random bi-phase operation of a power amplifier rejects the intrinsic spur of spread spectrum OOK transmitter by 22 dB. A proposed TSSS-OOK transmitter supports a variable spread spectrum, such as 1 b to 4 chips (1/4), 3/8, and 5/32 and a dual reception of the coherent as well as non-coherent mode, achieving 12-dB SNR gain. For the power optimized frequency synthesis, both a phase locked loop (PLL) and a frequency locked loop (FLL) are merged with a single voltage controlled oscillator as a dual-precision frequency synthesizer, where the high-precision PLL is activated for the coherent reception and the low power, moderate precision FLL is activated for the non-coherent reception. The single-chip transceiver in 90-nm CMOS occupies an active area of 2.4 mm2 and measures 1Mb/s, 22-dB spur-suppressed output spectrum, 5.5% EVM, and a sensitivity of −81 dBm at non-coherent mode and −93 dBm at coherent mode, dissipating 2.17 mW at TX and 0.614 mW at RX.
Auteurs: Seong Joong Kim;Chang Soon Park;Sang-Gug Lee;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 11.-2017, volume: 64, issue:11, pages: 2976 - 2987
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 2.8–3.8-GHz Low-Spur DTC-Based DPLL With a Class-D DCO in 65-nm CMOS
Résumé:
We present a digital phase-locked loop (DPLL) operating from 2.8 to 3.8 GHz with an on-chip 40-MHz reference crystal oscillator. The DPLL makes use of a class-D digitally controlled oscillator and a digital-to-time converter with a single-bit (bang-bang) phase detector. The DPLL displays an excellent behavior in terms of in-band fractional spurs, which are consistently below −65 dBc across the tuning range, thanks to a number of digital correction algorithms running in the background. The 65-nm CMOS DPLL consumes 18.2 mW for an in-band phase noise of −102 dBc/Hz at 100-kHz offset.
Auteurs: Ahmed Mahmoud;Pietro Andreani;Federico Pepe;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 11.-2017, volume: 27, issue:11, pages: 1010 - 1012
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 21-dBm $I/Q$ Digital Transmitter Using Stacked Output Stage in 28-nm Bulk CMOS Technology
Résumé:
This paper proposes the use of a high-power stacked output stage for a current-based in-phase/quadrature ( $I/Q$ ) direct digital to RF modulator (DDRM) in bulk CMOS. The main nonlinearities associated with implementing the stacked transistor on top of the $I/Q$ DDRM are easily compensated by a simple 2-D digital predistortion. A prototype implemented in 28-nm bulk CMOS achieves a saturated output power ( $P_{textrm {SAT}}$ ) of 25 dBm and a peak output power ( $P_{textrm {out}}$ ) of 21 dBm at 1-GHz carrier frequency ( $f_{c}$ ). Their corresponding efficiencies are 45% power added efficiency and 33% system efficiency ( $eta _{mathrm{ sys}}$ ), respectively. In addition, it achieves 11.5% $eta _{mathrm{ sys}}$ with a −30.5-dB error vector magnitude when transmitting a 40-MHz 64 quadrature amplitude modulation wireless local area network (WLAN) signal. The WLAN signal is transmitted at 12-dBm average $P_{textrm {out}}$ , and at 1-GHz $f_{c}$ with 8.73-dB peak to average power ratio (peak $P_{textrm {out}}$ of 20.73 dBm).
Auteurs: Wagdy M. Gaber;Piet Wambacq;Jan Craninckx;Mark Ingels;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 11.-2017, volume: 65, issue:11, pages: 4744 - 4757
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 28-GHz Low-Power Phased-Array Receiver Front-End With 360° RTPS Phase Shift Range
Résumé:
A low-power 28-GHz phased-array receiver (RX) front end is presented that incorporates a low-power low-noise amplifier (LNA) and a passive reflection-type phase shifter (RTPS) capable of 360° phase shift with 5-b phase resolution and low gain variation. Passive phase shifters are limited by tradeoffs between phase resolution, insertion loss, and phase shift range. The proposed RTPS load design and optimization approach leads to a 28-GHz RTPS achieving the state-of-the-art insertion loss with 360° phase shift range and low loss variation across the phase shift. The LNA adopts a transformer-coupled neutralization architecture that increases available gain, enabling lower power consumption. The phased-array front end is designed for Ka-band applications and has been implemented in 65-nm CMOS. The measured RTPS achieves 360° phase shift with 7.75 ± 0.3 dB insertion loss and an rms phase error of 0.3° at 28 GHz. The low-power phased-array RX front end has an overall gain of 9.5 ± 0.4 dB and noise figure <5.5 dB at 28 GHz. The RX front end consumes 10 mW from a 0.9-V supply with phase shifter and an LNA active area of 0.16 and 0.32 mm2, respectively, in 65-nm CMOS, demonstrating its suitability for low-power phased-array RX for emerging wireless links.
Auteurs: Robin Garg;Arun S. Natarajan;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 11.-2017, volume: 65, issue:11, pages: 4703 - 4714
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 3-D Joint Simulation Platform for Multiband Remote Sensing
Résumé:
Canopy radiation and scattering signals contain abundant vegetation information. Many biophysical parameters can be quantitatively retrieved with the help of canopy radiation and scattering models. Joint simulation of three-dimensional (3-D) models for multiband that combines the advantages of different spectral (frequency) domains could be a useful tool for validation in remote sensing. This manuscript presents a 3-D joint simulation platform (3-DMultiSim) that simulates spectral responses from visible to microwave bands. We validated our platform with the corn field experimental data at the Huailai testing site of the Chinese Academy of Sciences. The correlation coefficients between the validation data and the simulation results were higher than 0.92, while the relative mean deviation was 15%. For the thermal infrared band, the correlation coefficient was 0.91, but the variation of the simulated directional bright temperature from 2 π space was less than 0.4 °C. The reason may be due to the model limitation at high leaf area index (LAI). For the microwave bands, the simulation data and the validation data had the best consistency at L band, whereas the same trend but bigger deviation at X - and C-band. As an application of the platform, we performed sensitivity analyses of the radiation and scattering responses to LAI and incident-observation geometries at multiband. The simulation results were analyzed quantitatively. Further applications of the joint simulation platform are proposed.
Auteurs: Yang Zhang;Qinhuo Liu;Longfei Tan;Huaguo Huang;Wenjian Ni;Tiangang Yin;Wenhan Qin;Guoqing Sun;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 11.-2017, volume: 10, issue:11, pages: 4763 - 4778
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 3-D Smoothed-Particle Hydrodynamics Model of Electrode Erosion
Résumé:
Results from a smoothed-particle hydrodynamics (SPH) method of modeling electrode ablation in pulsed power systems are presented. The model follows numerous previous studies on electrode erosion in which the primary mechanism is conductive heat transfer. Total eroded mass as a function of peak current, frequency, and circuit damping were compared to theoretical and experimental data. The results indicate an average of a 16% deviation of the SPH code from the analytical prediction; however, most of the SPH data points qualitatively fall close to or within experimental ranges. The results indicate the potential of the SPH code to effectively model fusion propulsion reactor components for use in space travel.
Auteurs: Mitchell A. Rodriguez;Jason T. Cassibry;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 11.-2017, volume: 45, issue:11, pages: 3030 - 3037
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 312-GHz CMOS Injection-Locked Radiator With Chip-and-Package Distributed Antenna
Résumé:
This paper presents an injected-locked THz radiator integrating a half-quadrature voltage-controlled oscillator (HQVCO), four injection-locked frequency quadruplers (ILFQs), and a chip-and-package distributed antenna (DA). At the system level, an architecture based on injection locking is employed to allow individual optimization of the output power and the phase noise. At the circuit level, intrinsic-delay compensation and harmonic boosting techniques are proposed to optimize the phase noise of the HQVCO and the output power of the ILFQs, respectively. The proposed DA composed of four exciting elements on silicon chip and a primary radiator in low-temperature co-fired ceramic (LTCC) package features a wide bandwidth of 13% and a gain of 3.8 dBi without using lens at 312 GHz. Implemented in a 65-nm CMOS process, the radiator system occupying a core area of 0.36 mm2 achieves output frequency from 311.6 to 315.5 GHz and maximum equivalent isotropically radiated power (EIRP) of 10.5 dBm while consuming 300 mW. The output phase noise measures −109.3 dBc/Hz at 10-MHz offset and the dc-to-THz efficiency is 0.42%.
Auteurs: Liang Wu;Shaowei Liao;Quan Xue;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 2920 - 2933
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 40-Gb/s Quarter-Rate SerDes Transmitter and Receiver Chipset in 65-nm CMOS
Résumé:
This paper presents a 40-Gb/s transmitter (TX) and receiver (RX) chipset for chip-to-chip communications in a 65-nm CMOS process. The TX implements a quarter-rate multi-multiplexer (MUX)-based four-tap feed-forward equalizer (FFE), where a charge-sharing-effect elimination technique is introduced into the 4:1 MUX to optimize its jitter performance and power efficiency. The RX employs a two-stage continuous-time linear equalizer as the analog front end and integrates a low-cost sign-based zero-forcing engine relying on edge-data correlation to automatically adjust the tap weights of the TX-FFE. By embedding low-pass filters with an adaptively adjusting bandwidth into the data-sampling path and adopting high-linearity compensating phase interpolators, the clock data recovery achieves both high jitter tolerance and low jitter generation. The fabricated TX and RX chipset delivers 40-Gb/s PRBS data at BER < 10−12 over a channel with > 16-dB loss at half-baud frequency, while consuming a total power of 370 mW.
Auteurs: Xuqiang Zheng;Chun Zhang;Fangxu Lv;Feng Zhao;Shuai Yuan;Shigang Yue;Ziqiang Wang;Fule Li;Zhihua Wang;Hanjun Jiang;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 2963 - 2978
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 54.4–90 GHz Low-Noise Amplifier in 65-nm CMOS
Résumé:
This paper proposes a transformer-based broadband low-noise amplifier (LNA) for millimeter-wave application. The proposed LNA has four common-source stages. Three transformers are used to connect the drains of the former transistors and the sources of the following transistors to boost the transconductances of the following transistors. Thus, the gain of the circuit is effectively increased. In addition, the noise figure (NF) is decreased because the noise contributions of the following stages are further suppressed by the application of the transformers. To enhance the gain bandwidth, the gate inductor in each inter-stage matching network is independently adjusted to separate the main poles of the four stages. The LNA is demonstrated using a commercial 65-nm CMOS process. According to the measurement results, a maximum gain of 17.7 GHz at 67 GHz and a 3-dB gain bandwidth of 35.6 GHz are achieved. The measured NF is 5.4–7.4 dB at 54–67 GHz. The tested input 1-dB gain compression point (IP $_{1,text {dB}}$ ) ranges from −15.4 to −11.7 dBm in the entire 3-dB gain bandwidth. With 1-V power supply, the LNA consumes 19-mA dc current. The chip size is only 0.37 mm2 with all pads.
Auteurs: Yiming Yu;Huihua Liu;Yunqiu Wu;Kai Kang;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 2892 - 2904
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 6 A, 93% Peak Efficiency, 4-Phase Digitally Synchronized Hysteretic Buck Converter With ±1.5% Frequency and ±3.6% Current-Sharing Error
Résumé:
A four-phase, quasi-current-mode hysteretic buck converter with digital frequency synchronization, online comparator offset-calibration and, digital current-sharing control is presented. The switching frequency of the hysteretic converter is digitally synchronized to the input clock reference with less than ±1.5% error in the switching frequency range of 3–9.5 MHz. The online offset calibration cancels the input-referred offset of the hysteretic comparator and enables ±1.1% voltage regulation accuracy. Maximum current-sharing error of ±3.6% is achieved by a duty-cycle-calibrated delay line-based pulsewidth modulation generator, without affecting the phase synchronization timing sequence. In light-load conditions, individual converter phases can be disabled, and the final stage power converter output stage is segmented for high efficiency. The dc–dc converter achieves 93% peak efficiency for $V_{i}= 2$ V and $V_{o}= 1.6$ V.
Auteurs: Ming Sun;Zhe Yang;Kishan Joshi;Debashis Mandal;Philippe Adell;Bertan Bakkaloglu;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 3081 - 3094
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 60 GHz Horizontally Polarized Magnetoelectric Dipole Antenna Array With 2-D Multibeam Endfire Radiation
Résumé:
A novel substrate integrated waveguide (SIW) fed horizontally polarized endfire magnetoelectric (ME) dipole antenna composed of an open-ended SIW with broad walls vertical to substrates and a pair of electric dipoles realized by four metallic patches is proposed. Simple configuration and excellent performance including an impedance bandwidth of 46.5%, stable gain of around 6 dBi, and symmetrical cardioid radiation patterns with low backward radiation and low cross polarizations are achieved. An SIW 90° twist integrated in three-layered substrate is implemented in order to connect the ME-dipole antenna conveniently to the SIW beam-forming network with broad walls parallel to substrates. A $4 times 4$ SIW Butler matrix with a three-layered zigzag topology is then designed, which enables a size reduction of 45% for the matrix compared with conventional single-layered configuration but not affecting its operating characteristics. By employing a $2 times 4$ ME-dipole array with 90° twists, two-folded Butler matrices and four SIW 3 dB E-plane couplers, a multibeam endfire array that can radiate eight beams scanning in two dimensions is designed at the 60 GHz band. The fabricated prototype verifies that a wide impedance bandwidth of 22.1%, gain varying from 10 to 13 dBi and stable radiation beams can be obtained. Due to good performance and the compact structure with low fabrication costs, the proposed design would be attractive for future millimeter-wave wireless applications including 5G communications and the WiGig system.
Auteurs: Jingxue Wang;Yujian Li;Lei Ge;Junhong Wang;Kwai-Man Luk;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 5837 - 5845
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A 7.1-fJ/Conversion-Step 88-dB SFDR SAR ADC With Energy-Free “Swap To Reset”
Résumé:
The digital-to-analog converter (DAC) in SAR anolog-to-digital converters (ADCs) is often dominant for both power consumption and linearity. Dedicated switching schemes can save power, but mostly focus on conversion energy, whereas the DAC reset can consume significant energy as well. This paper presents an energy-free DAC reset scheme, “swap to reset,” for charge-redistribution SAR ADCs. It is widely applicable to existing low-power switching schemes. Additionally, to limit complexity while maintaining most of the energy savings, it can be utilized for the MSBs of the DAC only while the LSBs use conventional reset. To demonstrate the scheme, it is applied to the 2 MSBs of a 12-b SAR ADC using a split-monotonic DAC in 65-nm CMOS, resulting in an energy saving of 33% for the DAC or 18% for the whole ADC. Besides the “swap to reset,” a rotation is also applied to the 2 MSBs, hence enhancing the linearity to 88-dB spurious free dynamic range. The SAR ADC operates at 0.8-V power supply and 40 kS/s, achieving an signal to noise and distortion ratio of 64.2 dB and a Figure of Merit of 7.1-fJ/conversion step.
Auteurs: Maoqiang Liu;Arthur H. M. van Roermund;Pieter Harpe;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 2979 - 2990
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Band-Limited Canonical Piecewise-Linear Function-Based Behavioral Model for Wideband Power Amplifiers
Résumé:
A band-limited canonical piecewise-linear function (CPWL)-based model is proposed for wideband power amplifiers (PAs). The model has a similar structure of the band-limited dynamic deviation reduction (DDR) Volterra series model but without high-order terms and long finite impulse response filters, which are replaced by CPWL. The model has lower complexity and more flexibility than the band-limited DDR Volterra series model and the model parameters can be estimated by the least-square method. Experimental results show that the proposed model nearly gives the same normalized mean square error and digital predistortion performance as the band-limited Volterra series when a wideband PA is excited by a 5-carrier long-term evolution advanced signal of 100-MHz bandwidth.
Auteurs: Jianfeng Zhai;Yang Li;Chao Yu;Lei Zhang;Jianyi Zhou;Wei Hong;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 11.-2017, volume: 27, issue:11, pages: 1022 - 1024
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Basic Theory of Induction Heating for a Wind-Powered Thermal Energy System
Résumé:
A wind-powered thermal energy system (WTES) can convert wind power efficiently into thermal energy to be stored for stable and low-cost electric power generation. This paper derives a basic formula of induction heating for heat generation in the WTES. The dependence of heat generation on the number of magnetic poles and material parameters of the conductor is analytically derived. The maximal heat generation is given by a simple function of the conductor radius, rotational speed, and applied magnetic flux density. Finite-element eddy-current analysis shows that the derived analytical solution gives a reasonable estimation of heat generation.
Auteurs: Tetsuji Matsuo;Toru Okazaki;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 5
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Batch Packet Server (BPS) Based Discontinuous Reception Mechanism for Energy Saving
Résumé:
LTE/LTE-A systems have specified a discontinuous reception (DRX) mechanism for battery energy saving of user equipment (UE). Until now, most analytical works have been on the DRX mechanism based on a single packet server. However, a single packet server typically yields low performance in energy saving under high arrival rates. On the other hand, practical LTE/LTE-A systems can allocate a variable size of resource for UE at one service time. To reflect the variable size of resource allocation and analyze the exact DRX mechanism under high arrival rates, we first model the DRX mechanism based on a batch server with varying buffer thresholds and server capacities. We also investigate the effect of system parameters such as buffer threshold, server capacity, DRX cycle, and inactivity timer in terms of delay and sleep ratio. Then, we find the optimal system parameter values of the batch packet server based DRX mechanism while satisfying the given delay requirements and maximizing the sleep ratio simultaneously. Finally, we show that the batch packet server yields the longer sleep ratio from 0.6 to 0.9 at high arrival rates, compared to a single packet server.
Auteurs: Eunmi Chu;Nah-Oak Song;Dan Keun Sung;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 11.-2017, volume: 66, issue:11, pages: 10557 - 10561
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Batch-Mode Regularized Multimetric Active Learning Framework for Classification of Hyperspectral Images
Résumé:
Techniques that combine multiple types of features, such as spectral and spatial features, for hyperspectral image classification can often significantly improve the classification accuracy and produce a more reliable thematic map. However, the high dimensionality of the input data and the typically limited quantity of labeled samples are two key challenges that affect classification performance of supervised methods. In order to simultaneously deal with these issues, a regularized multimetric active learning (AL) framework is proposed which consists of three main parts. First, a regularized multimetric learning approach is proposed to jointly learn distinct metrics for different types of features. The regularizer incorporates the unlabeled data based on the neighborhood relationship, which helps avoid overfitting at early stages of AL, when the quantity of training data is particularly small. Then, as AL proceeds, the regularizer is also updated through similarity propagation, thus taking advantage of informative labeled samples. Finally, multiple features are projected into a common feature space, in which a new batch-mode AL strategy combining uncertainty and diversity is utilized in conjunction with k-nearest neighbor classification to enrich the set of labeled samples. In order to evaluate the effectiveness of the proposed framework, the experiments were conducted on two benchmark hyperspectral data sets, and the results were compared to those achieved by several other state-of-the-art AL methods.
Auteurs: Zhou Zhang;Melba M. Crawford;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 11.-2017, volume: 55, issue:11, pages: 6594 - 6609
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Bayesian Additive Model for Understanding Public Transport Usage in Special Events
Résumé:
Public special events, like sports games, concerts and festivals are well known to create disruptions in transportation systems, often catching the operators by surprise. Although these are usually planned well in advance, their impact is difficult to predict, even when organisers and transportation operators coordinate. The problem highly increases when several events happen concurrently. To solve these problems, costly processes, heavily reliant on manual search and personal experience, are usual practice in large cities like Singapore, London or Tokyo. This paper presents a Bayesian additive model with Gaussian process components that combines smart card records from public transport with context information about events that is continuously mined from the Web. We develop an efficient approximate inference algorithm using expectation propagation, which allows us to predict the total number of public transportation trips to the special event areas, thereby contributing to a more adaptive transportation system. Furthermore, for multiple concurrent event scenarios, the proposed algorithm is able to disaggregate gross trip counts into their most likely components related to specific events and routine behavior. Using real data from Singapore, we show that the presented model outperforms the best baseline model by up to 26 percent in $R^2$ and also has explanatory power for its individual components.
Auteurs: Filipe Rodrigues;Stanislav S. Borysov;Bernardete Ribeiro;Francisco C. Pereira;
Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence
Date publication: 11.-2017, volume: 39, issue:11, pages: 2113 - 2126
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A BPPE Algorithm for Instantly Decodable Network Coding in Wireless Broadcasting
Résumé:
Instantly decodable network coding (IDNC) is a low-cost network coding technique for recovering unattained packets by multiple receivers. Due to its NP-hard nature, finding the optimal IDNC coded packets is intractable. In the well-known graph-based method proposed by Sorour et al., a maximum weight clique selection problem is formulated as an approximation, and a heuristic algorithm called maximum weight clique (MWC) is proposed in maximizing the clique weight. In this letter, a base policy-based partial enumeration (BPPE) algorithm is proposed in addressing the maximum weight clique selection problem. In particular: 1) the necessity of constructing the IDNC graph as in MWC is eliminated and 2) different enumeration lengths could be chosen, so that a consistent performance-run time tradeoff could be achieved. Simulation results testify the effectiveness of BPPE in addressing the maximum weight clique selection problem over existing algorithms in terms of performance-run time tradeoff.
Auteurs: Youyun Xu;Jian Wang;Kui Xu;Dongmei Zhang;Bin Gao;
Apparue dans: IEEE Communications Letters
Date publication: 11.-2017, volume: 21, issue:11, pages: 2340 - 2343
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Branch-&-Bound Test-Access-Mechanism Optimization Method for Multi- $V_{mathrm{ dd}}$ SoCs
Résumé:
The use of multiple voltage levels introduces new challenges for testing multi- ${V_{mathrm{ dd}}}$ systems-on-chip (SoCs). Time-division-multiplexing (TDM) tackles many of these challenges and offers very effective test-schedules. However, the effectiveness of TDM for minimizing test time depends on the test-access-mechanism (TAM) in the SoC. Single- $ {V_{mathrm{ dd}}}$ TAM optimization techniques consider neither the highly constrained test environment of multi- $ {V_{mathrm{ dd}}}$ SoCs nor the benefits provided by TDM, therefore they are not suitable for multi- $ {V_{mathrm{ dd}}}$ SoCs. In this paper, we propose the first TAM optimization technique for multi- $ {V_{mathrm{ dd}}}$ SoCs. The proposed method exploits unique scheduling opportunities and flexibility offered by TDM, and by the means of a branch-&-bound approach, it quickly identifies the most effective TAM configurations. Experiments using large benchmark SoCs as well as SoCs from industry highlight the benefits of the proposed technique on multi- $ {V_{mathrm{ dd}}}$ designs, for both single-site and multisite test applications.
Auteurs: Fotis Vartziotis;Xrysovalantis Kavousianos;Panagiotis Georgiou;Krishnendu Chakrabarty;
Apparue dans: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Date publication: 11.-2017, volume: 36, issue:11, pages: 1911 - 1924
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Broad Beamforming Approach for High-Mobility Communications
Résumé:
To leverage the benefits of multiple-input multiple-output in high-mobility communications, this paper proposes a broad beamforming approach (BBA), which focuses a broad beam on a moving user on the basis of the moving user's current location and velocity information. So, the moving user can be covered and tracked by the broad beam and is able to achieve high received signal-to-noise ratio (SNR). An optimization problem is formulated to minimize the required power by jointly optimizing the transmit and the receiving beam vectors, while guaranteeing the desired information rate of the moving user. Since the problem is with infinite constraints and has no known solution, we design an efficient algorithm to solve it, where the transmit and receiving beam vectors are optimized by using semidefinite relaxation alternatively in an iterative manner. Simulation results show that by using our proposed BBA, the desired information rate of the high-mobility user can be guaranteed. Compared with existing schemes, with the same power consumption, our proposed scheme can enhance the SNR greatly within the moving region of interest. Besides, by increasing the number of transmit antennas, the required power can be further decreased.
Auteurs: Ke Xiong;Beibei Wang;Chunxiao Jiang;K. J. Ray Liu;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 11.-2017, volume: 66, issue:11, pages: 10546 - 10550
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Brushless Dual-Mechanical-Port Dual-Electrical-Port Machine With Spoke Array Magnets in Flux Modulator
Résumé:
Brushless dual-mechanical-port dual-electrical-port (BLDD) permanent magnet (PM) machines have been gaining more and more attentions in recent years, with the merits of two decoupled rotors and contactless torque transmission. However, existing BLDD machines tend to suffer from low torque density due to low working flux density. In this paper, a BLDD machine with spoke array PMs in flux modular is proposed, which improves the torque density significantly. The structure and operation principle of the proposed machine is introduced. Detailed performance comparison between three different BLDD machine topologies, i.e., surface-mounted PM BLDD machine, flux-bidirectional modulation BLDD machine, and the proposed BLDD machine, is presented through finite-element analysis. The analyzing results show that although the modulated magnetic field coupled with the modulation winding is slightly reduced, the torque transmission capability of the regular winding in the proposed BLDD machine is significantly enhanced when compared with that of its two counterparts.
Auteurs: Xiang Ren;Dawei Li;Ronghai Qu;Tianjie Zou;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 6
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Closed Normal Form Solution Under Near-Resonant Modal Interaction in Power Systems
Résumé:
Normal form (NF) is an effective tool to quantitatively analyze nonlinear modal interaction, which is believed to contribute to the complex nonlinear dynamics in power systems. However, in conventional NF analysis, the solution under resonance condition cannot be expressed in a closed form. Hence the NF analysis of power system higher order modal interaction was limited to nonresonant cases, or directly neglecting the resonant terms. In this paper, the NF solutions under modal resonance are derived, by means of the polynomial vector space decomposition. The obtained solution is in a simple closed form, including both the nonresonant part and the resonant part. Numerical simulations are performed to verify the effectiveness of the proposed approach. The results show that, under modal resonant conditions, neglecting the resonant terms may cause significant errors to the obtained numerical solutions, whereas including modal resonant terms in NF may increase the accuracy of the analysis. Finally, the approach proposed in this paper is compared with the modal series method, which, unlike NF method, is not limited by resonant condition. The results show that the proposed method in this paper has better performance in both accuracy and computing time.
Auteurs: Zhouqiang Wang;Qi Huang;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 11.-2017, volume: 32, issue:6, pages: 4570 - 4578
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Cloud Detection Method Based on Relationship Between Objects of Cloud and Cloud-Shadow for Chinese Moderate to High Resolution Satellite Imagery
Résumé:
Cloud detection of satellite imagery is very important for quantitative remote sensing research and remote sensing applications. However, many satellite sensors do not have enough bands for a quick, accurate, and simple detection of clouds. Particularly, the newly launched moderate to high spatial resolution satellite sensors of China, such as the charge-coupled device on-board the Chinese Huan Jing 1 (HJ-1/CCD) and the wide field of view (WFV) sensor on-board the Gao Fen 1 (GF-1), only have four available bands including blue, green, red, and near infrared bands, which are far from the requirements of most could detection methods. In order to solve this problem, an improved and automated cloud detection method for Chinese satellite sensors called object-oriented cloud and cloud-shadow matching method (OCM) is presented in this paper. It first modified the automatic cloud cover assessment (ACCA) method, which was developed for Landsat-7 data, to get an initial cloud map. The modified ACCA method is mainly based on threshold and different threshold settings produce different cloud maps. Subsequently, a strict threshold is used to produce a cloud map with high confidence and large amount of cloud omission and a loose threshold is used to produce a cloud map with low confidence and large amount of commission. Second, a corresponding cloud-shadow map is also produced using the threshold of near-infrared band. Third, the cloud maps and cloud-shadow map are transferred to cloud objects and cloud-shadow objects. Cloud and cloud-shadow are usually in pairs; consequently, the final cloud and cloud-shadow maps are made based on the relationship between cloud and cloud-shadow objects. The OCM method was tested using almost 200 HJ-1/CCD and GF-1/WFV images across China and the overall accuracy of cloud detection is close to 90%.
Auteurs: Bo Zhong;Wuhan Chen;Shanlong Wu;Longfei Hu;Xiaobo Luo;Qinhuo Liu;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 11.-2017, volume: 10, issue:11, pages: 4898 - 4908
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A CMOS Antiphase Power Amplifier With an MGTR Technique for Mobile Applications
Résumé:
In this paper, a CMOS antiphase power amplifier (PA) is presented with a multigate transistor (MGTR) technique that improves its linearity. The drive stage of the PA is biased in the subthreshold region, such as in class C, to realize the antiphase technique. The nonlinearity of the power stage of the PA is canceled out using the third-order intermodulation distortion and phase distortion of the drive stage. The cancellation effect is further optimized and enhanced without any performance degradation with the aid of the proposed MGTR technique at the drive stage. Unlike the traditional technique, which suppresses the nonlinearity of the PA, the MGTR technique is used to enhance the nonlinearity of the drive stage to cancel out the significant nonlinearity of the power stage. The proposed PA is fabricated with a 180-nm RF CMOS process and used to verify the linearity by WCDMA and LTE signals. The measurement results show an average output power of 25.8 dBm, PAE of 28%, and error vector magnitude of 3% at 1.85 GHz for the WCDMA. The PA also shows an average output power of 24.4–25.8 dBm at 1.7–2.0 GHz for the WCDMA. The PA is verified for LTE signals with 10 MHz of bandwidth/16 QAM and with 20 MHz of bandwidth/64 QAM. No digital predistortion or off-chip components are utilized.
Auteurs: Jonghoon Park;Changhyun Lee;Jinho Yoo;Changkun Park;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 11.-2017, volume: 65, issue:11, pages: 4645 - 4656
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A CMOS UHF Harmonic Rejection Transceiver With 2-D LO Phase Calibration for TV White Space Applications
Résumé:
A CMOS ultra-high frequency-band RF transceiver based on 8-phase harmonic rejection mixer (HRM) architecture with an integrated fractional-N PLL synthesizer is presented for television white space applications. A divide-by-2 and a phase interpolator (PI) circuit are used to generate the 8-phase LO signals for the HRM. The synthesizer output frequency is two times higher than the desired band frequency. The PI is tunable to allow 7-bit calibration of 45° and 135° LO phases. A systematic 2-D calibration scheme that is applicable to both the receiver and transmitter is described. It is demonstrated that only 45° and 135° LO phase calibration is sufficient to minimize the third and fifth harmonic components. Implemented in 0.18- $mu$ m CMOS, the RF transceiver covers 470–806 MHz, achieving the third and fifth harmonic suppressions below −48 and −56 dBc at the receiver, and the harmonic emission below −51 dBc at the transmitter.
Auteurs: Seunghyeon Kim;Jihoon Sohn;Hyunchol Shin;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 11.-2017, volume: 64, issue:11, pages: 1297 - 1301
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A CO2 Profile Retrieving Method Based on Chebyshev Fitting for Ground-Based DIAL
Résumé:
The vertical profile of atmospheric CO2 is of great scientific significance in identifying carbon sinks and sources, and estimating CO2 emissions or uptakes. Differential absorption Light Detection And Ranging (DIAL), has been widely accepted as the most promising technique to sense atmospheric CO2. The classical method to retrieve measurements, generated from range-resolved detection, is derived from differentiating the measured column content, but its performance in dealing with aerosol backscatter signals is poor. To address this issue, this paper proposes a derivative method, which is based on Chebyshev fitting to the measured differential absorption optical depth. We created a performance evaluation model to assess the performance of the proposed method. Simulations revealed that the error of a single CO2 profile in data retrieval can be reduced to less than 4 ppm in 6000 m. The precision of long-term mean CO2 profile is expected to be less than 1 ppm. We believe that this novel method can be used in other applications also, e.g., trace gas measurements collected using DIAL, especially when the signal-to-noise-ratio of received signal is small.
Auteurs: Ge Han;Xiaohui Cui;Ailin Liang;Xin Ma;Teng Zhang;Wei Gong;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 11.-2017, volume: 55, issue:11, pages: 6099 - 6110
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Coexistence of Short- and Long-Range Ferromagnetic Interactions in La1–xKxMnO3 Compounds
Résumé:
In this paper, we present a detailed study on the critical behavior around the ferromagnetic (FM)–paramagnetic phase transition in La1−xKxMnO3 (LKMO) compounds with $x = 0.05 - 0.20$ . Our results pointed out the easiness in controlling the value of $T_{C}$ from 212 to 306 K by increasing K-doping concentration (x) from 0.05 to 0.20. Analyzing temperature and magnetic field dependences of magnetization M(T, H) at temperatures around $T_{C}$ reveals all the samples undergoing the second-order phase transition. Using the modified Arrott plots, the Kouvel–Fisher, and the critical isotherm analysis methods, we have found that the values of exponent $beta $ in the range of 0.435–0.493, which deviate from the mean-field theory (MFT) for the long-range FM interactions, indicating a coexistence of short- and long-range FM orders. We also pointed out that the critical exponents ( $beta $ and $delta)$ depend strongly on K-concentration, shifting from values approaching those of the MFT ( $beta = 0.5$ and $delta = 3$ ) to values approaching those of the 3-D-Heisenberg model ( $beta = 0.365$ and $delta = 4.80$ ). In con- rast, the value of the exponent $gamma (=1.222 - 1.249)$ is almost independent of K-concentration. It suggests that K-doping favors establishing a short-range FM order in LKMO compounds.
Auteurs: Yikyung Yu;Dinh Chi Linh;Tran Dang Thanh;Pham Ngoc Dan;Nguyen Van Dang;Hong-Guang Piao;Daniel M. Tartakovsy;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 4
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Compact Analog Complex Cross-Correlator for Passive Millimeter-Wave Imager
Résumé:
The design, analysis, implementation, and measurement of a compact analog complex cross-correlator for passive millimeter-wave imaging applications are presented in this paper. The correlator uses the “add and square” and “subtract and square” detection scheme by adopting the Schottky diodes and RF distribution network. Meanwhile, in order to realize the correlator with a compact size and low cost, commercially available surface mounting devices and multilayer PCB technique are employed. The relationship between the phase error of the correlator and the phase unbalance of the RF distribution network is also analyzed. Single-frequency test is applied to the correlator, and the results of the measurement reveal that the correlator operates well within the frequency range of 1.5-2.5 GHz. Moreover, a measurement system based on an actual imaging scenario is also developed to characterize the performance of the correlator when injected with correlated broadband noise signals, and the measurement results show that the correlator is well suited for imaging applications. The bandwidth of the current version correlator is around 1 GHz, but it could easily be changed by replacing distributed components.
Auteurs: Chao Wang;Xin Xin;Muhammad Kashif;Jungang Miao;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 11.-2017, volume: 66, issue:11, pages: 2997 - 3006
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Compact High-Performance Programmable-Gain Analog Front End for HomePlug AV2 Communication in 0.18- $mu text{m}$ CMOS
Résumé:
An analog front end suitable for powerline communication HomePlug AV2 is firstly presented. Targeting different input power level, an attenuation-programmable gain amplifier (AT-PGA) and a low- noise amplifier are adopted as the input stage of receiver, respectively, followed by a fourth-order low-pass filter and a PGA with a build-in feedback control to improve linearity and stay constant bandwidth. A line driver with programmability in transmitter is designed to synthesize output impedance for maximizing the power density transmission ratio in power lines characterized by an impedance of $50~Omega $ . The analog front end is realized in 0.18- $mu text{m}$ 3.3-V CMOS technology with power consumption of 160 mW (receiver) and 350 mW (transmitter) that occupies a 5.75-mm $^{2}$ die area (dual channel). The receiver exhibits a bandwidth of 100 MHz and a gain range from −26.2 to 21 dB, with a minimum noise figure of 20.2 dB at maximum gain 21 dB and maximum IIP3 of 36.1 dBm at minimum gain −26.2 dB. The transmitter achieves 47-dB low-band multi-tone power ratios (MTPR) and 9.6-dB high-band MTPR.
Auteurs: Zhangming Zhu;Jingyu Wang;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 11.-2017, volume: 64, issue:11, pages: 2858 - 2870
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Comprehensive Analysis of 5G Heterogeneous Cellular Systems Operating Over $kappa$ – $mu$ Shadowed Fading Channels
Résumé:
Emerging cellular technologies such as those proposed for use in 5G communications will accommodate a wide range of usage scenarios with diverse link requirements. This will necessitate operation over a versatile set of wireless channels ranging from indoor to outdoor, from line-of-sight (LOS) to non-LOS, and from circularly symmetric scattering to environments which promote the clustering of scattered multipath waves. Unfortunately, many of the conventional fading models lack the flexibility to account for such disparate signal propagation mechanisms. To bridge the gap between theory and practical channels, we consider $kappa$ $mu$ shadowed fading, which contains as special cases the majority of the linear fading models proposed in the open literature. In particular, we propose an analytic framework to evaluate the average of an arbitrary function of the signal-to-noise-plus-interference ratio (SINR) over $kappa$ $mu$ shadowed fading channels by using an orthogonal expansion with tools from stochastic geometry. Using the proposed method, we evaluate the spectral efficiency, moments of the SINR, and outage probability of a $K$ -tier heterogeneous cellular network with $K$ classes of base stations (BSs), differing in terms of the transmit power, BS density, shadowing, and fading characteristics. Building upon these results, we provide important new insights into the network performance of these emerging wireless applications while considering a diverse range of fading conditions and link qualitie- .
Auteurs: Young Jin Chun;Simon L. Cotton;Harpreet S. Dhillon;F. Javier Lopez-Martinez;Jose F. Paris;Seong Ki Yoo;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 11.-2017, volume: 16, issue:11, pages: 6995 - 7010
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Comprehensive Big-Data-Based Monitoring System for Yield Enhancement in Semiconductor Manufacturing
Résumé:
In this paper, we focus on yield analysis task where engineers identify the cause of failure from wafer failure map patterns and manufacturing histories. We organize yield analysis task into the following three stages, namely, failure map pattern monitoring, failure cause identification, and failure recurrence monitoring, and incorporate machine learning and data mining technologies into each stage to support engineers’ work. The important point is that big data analysis enables comprehensive and long-term monitoring automation. We make use of fast and scalable methods of clustering and pattern mining and realize daily comprehensive monitoring with massive manufacturing data. We also apply deep learning, which has been an innovative core technology of machine learning in recent years, to classification of wafer failure map patterns, and explore its performance in detail. Finally, these machine learning and data mining techniques are integrated into an automated monitoring system with interfaces familiar to engineers to attain large yield enhancement.
Auteurs: Kouta Nakata;Ryohei Orihara;Yoshiaki Mizuoka;Kentaro Takagi;
Apparue dans: IEEE Transactions on Semiconductor Manufacturing
Date publication: 11.-2017, volume: 30, issue:4, pages: 339 - 344
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Comprehensive Reliability Assessment of Fault-Resilient Network-on-Chip Using Analytical Model
Résumé:
The component’s failure in network-on-chips (NoCs) has been a critical factor on the system’s reliability. In order to alleviate the impact of faults, fault tolerance has been investigated in the recent years to enhance NoC’s robustness. Due to the vast selection of fault-tolerance mechanisms and critical design constraints, selecting and configuring an appropriate mechanism to satisfy the fault-tolerance requirements constitute new challenges for designers. Consequently, reliability assessment has become prominent for the early stages of manufacturing process to solve these problems. This paper approaches the fault-tolerance analysis by providing an analytical model to approximate the lifetime reliability and compares it with a system-level simulation. Based on the proposed approach, we measure the fault-tolerance efficiency using a new parameter, named reliability acceleration factor. The goal of this paper is to provide an efficient and accurate reliability assessment to help designers easily understand and evaluate the advantages and drawbacks of their potential fault-tolerance methods.
Auteurs: Khanh N. Dang;Akram Ben Ahmed;Xuan-Tu Tran;Yuichi Okuyama;Abderazek Ben Abdallah;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 11.-2017, volume: 25, issue:11, pages: 3099 - 3112
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Consensus Process [Standards News]
Résumé:
Addresses the concept of consensus when discussing the development of standards. A Consensus Process Standards are a consensus opinion of a group of subject matter experts (SMEs) who document and share their skills with the general users, who may not be experts. Standards are learnings based on the past to provide directions for the future. Standards are the language used by SMEs to pass their experience and knowledge to the users. What is consensus? Business Dictionary defines consensus as Middle ground in decision making, between total assent and total disagreement. Consensus depends on participants having shared values and goals, and on having broad agreement on specific issues and overall direction. Consensus implies that everyone accepts and supports the decision, and understands the reasons for making it.
Auteurs: Daleep Mohla;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 11.-2017, volume: 23, issue:6, pages: 71 - 81
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Continuous-Flow Memory-Based Architecture for Real-Valued FFT
Résumé:
This brief proposes a continuous-flow memory-based architecture for fast Fourier transform (FFT) computation for real-valued signals. The proposed architecture is based on a modified radix-2 algorithm, which removes redundant operations to reduce resource usage. A new data-flow graph and address mapping scheme are proposed that satisfy the requirement of continuous-flow operation and minimize the memory usage. The proposed processing element takes advantage of pipelined FFT architectures to avoid bank conflicts in each stage. Compared with prior works, the proposed design has the advantage of supporting continuous-flow operation and normal-order output while minimizing the resource usage.
Auteurs: Xiu-Bin Mao;Zhen-Guo Ma;Feng Yu;Qian-Jian Xing;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 11.-2017, volume: 64, issue:11, pages: 1352 - 1356
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Curve Network Sampling Strategy for Measurement of Freeform Surfaces on Coordinate Measuring Machines
Résumé:
One of the essential problems in the measurement of the freeform surfaces on a coordinate measuring machine is to design appropriate sampling plans to improve the industrial practice in terms of the tradeoff between the sampling accuracy and the efficiency. This paper presents a curve network sampling strategy to approximate the measured surface within a required accuracy while minimizing the cost and time for the measurement by adaptively deriving the optimal sampling locations. The method iteratively extracts two sets of iso-planar curves along two different directions on the parts to form a curve network, which is used to reconstruct the measured surfaces based on the Gordon surface fitting method. Two criteria are integrated to determine the locations of the sampled curves in the sampling process, including the surface complexity and the deviation of the reconstructed surfaces from the CAD model. Both the computer simulation and the actual measurement are conducted to verify the superior sampling efficiency of the proposed method to the conventional raster fashion sampling in measuring freeform surfaces.
Auteurs: Mingjun Ren;Lingbao Kong;Lijian Sun;ChiFai Cheung;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 11.-2017, volume: 66, issue:11, pages: 3032 - 3043
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Design of Rotor Bar Inclination in Squirrel Cage Induction Motor
Résumé:
The shape of rotor bar is important in squirrel cage induction motor (SCIM) performance, such as starting torque, operating torque, and operating efficiency. Some designs of increasing starting torque of motor may decrease motor efficiency. Moreover, some designed shapes of bar are so complicated to be manufactured. In this paper, the design is focused on the simple inclination of conventional shape of bar with keeping the rotor bar area constant. The effects of rotor bar inclination on starting torque, operating torque, and operating efficiency in SCIM are analyzed. The results showed that there is optimum inclination of rotor bar to improve all the performances together. An application to the 3.4 kW SCIM showed that the starting torque is increased from 17.53 to 17.64 $text {N}cdot text {m}$ , the operating torque from 11.19 to $11.26~text {N}cdot text {m}$ , and the operating efficiency from 94.18% to 94.81%.
Auteurs: Chang Geun Heo;Hui Min Kim;Gwan Soo Park;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 4
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Detector-Aware LDPC Code Optimization for Ultra-High Density Magnetic Recording Channels
Résumé:
In this paper, a detector-aware low-density parity-check (LDPC) code optimization algorithm is proposed for the ultra-high density magnetic recording channel, such as bit-patterned magnetic recording and two-dimensional magnetic recording, where a 2-D detector (2D-DET) is employed to combat 2-D intersymbol interference (2D-ISI) effects, by acquiring the variance of the 2D-ISI channel log-likelihood ratios corresponding to the specific 2D-DET. The new parameter builds a bridge of LDPC code optimization between the ISI-channel and the additive white Gaussian noise channel. Numerical results show that our proposed algorithms are more efficient in running time than other recently proposed optimization algorithms. Moreover, the protograph-based quasi-cyclic (QC) codes using the proposed optimization strategy, which have a low-complexity QC encoder structure with an effectual parallelizable protograph decoder composition, enjoy up to one order of magnitude performance gain in bit error rate over the other random codes that suffer from high error floors.
Auteurs: Lingjun Kong;Kui Cai;Pingping Chen;Bing Fan;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 4
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Distributed Game-Theoretic Approach for Target Coverage in Visual Sensor Networks
Résumé:
Visual sensor networks normally consist of a collection of camera sensors deployed randomly yet densely to fully cover a set of targets. Due to high redundancy incurred, it is possible to both preserve energy and enhance coverage quality by first switching off some sensors and then adjusting the orientations of the remaining ones. The problem is that no global knowledge of the environment is available to be used to decide which sensors should be switched off and which ones should adjust their orientations. In this paper, we propose a new distributed game theoretic approach to full target coverage. A potential game is formulated in which a utility function is designed to consider the tradeoff between coverage quality and energy consumption. In order to solve the game, we present a distributed payoff-based learning algorithm where each sensor has only access to its last two actions played and own utility values. Simulation results show that our proposed game-theoretic approach has greater energy efficiency and can extend the network lifetime, as compared with prior approaches.
Auteurs: Behrooz Shahrokhzadeh;Mehdi Dehghan;
Apparue dans: IEEE Sensors Journal
Date publication: 11.-2017, volume: 17, issue:22, pages: 7542 - 7552
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Drift-Tolerant Read/Write Scheme for Multilevel Memristor Memory
Résumé:
Memristor based crossbar memories are prime candidates to succeed the Flash as the mainstream nonvolatile memory due to their density, scalability, write endurance and capability of storing multibit per cell. In this paper, we present a memristor crossbar memory architecture that utilizes a reduced constraint read-monitored-write scheme. The proposed scheme supports multibit storage per cell and utilizes reduced hardware, aiming to decrease the feedback complexity and latency while still operating with CMOS compatible voltages. We additionally present a read technique that can successfully distinguish resistive states under the existence of resistance drift due to read/write disturbances in the array. We also provide derivations of analytical relations to set forth a design methodology in selecting peripheral device parameters.
Auteurs: Yalcin Yilmaz;Pinaki Mazumder;
Apparue dans: IEEE Transactions on Nanotechnology
Date publication: 11.-2017, volume: 16, issue:6, pages: 1016 - 1027
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Dynamic Leakage and Slew Rate Compensation Circuit for 40-nm CMOS Mixed-Voltage Output Buffer
Résumé:
This paper proposes a 40-nm CMOS $2 times {mathrm{ VDD}}$ buffer with slew rate (SR) variation compensated and dynamic leakage reduction during signal transitions. By using the dual variation detectors, five process corners for both nMOS and pMOS could be detected. Thus, the SR deviations will be significantly reduced by controlling the switches of the output stage accordingly. Besides, leakage reduction circuit will shut down current paths to reduce dynamic leakage after signal transitions are completed. This buffer design is implemented using the typical 40-nm CMOS process, where the active area is $0.052 times 0.213$ mm2. The measured worst case of SR variation improvement is 20.8% and 54.9% when VDDIO is 0.9 and 1.8 V, respectively. The peak dynamic leakage is reduced to 41.0% and 37.5% at 0.9 and 1.8 V, respectively.
Auteurs: Tzung-Je Lee;Tsung-Yi Tsai;Wei Lin;U-Fat Chio;Chua-Chin Wang;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 11.-2017, volume: 25, issue:11, pages: 3166 - 3174
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Fast Cloud Detection Algorithm Applicable to Monitoring and Nowcasting of Daytime Cloud Systems
Résumé:
The Advanced Himawari Imager (AHI) onboard Japanese geostationary satellite Himawari-8 provides two more visible, three more near-infrared, and six more infrared channels than the only one visible and four infrared channels available from the previous geostationary imager instruments. By taking advantage of AHI’s newly added channels 1, 3, and 4 with wavelengths centered at 0.46, 0.64, and $0.86~mu text{m}$ , respectively, a fast cloud detection algorithm is developed. Since the spectral differences of the reflectance between any two of AHI’s channels 1, 3, and 4 over clouds are smaller than those over land and ocean, a visible-based cloud index (VCI) for daytime cloud detection can thus be defined by the root mean square of the three differences between any two of these three channels. An AHI pixel is identified as cloudy if the VCI is smaller than a threshold, which has different values over ocean and land. Cloud detection is further adjusted by a bias correction using AHI channels 7 and 13. The average accuracy of the proposed simple cloud detection is comparable with those obtained from a more complicated cloud mask algorithm involving not only more channels but also model simulations. It is also found that the bias correction is needed mostly over cirrus clouds and Gobi.
Auteurs: Xiao-Yong Zhuge;Xiaolei Zou;Yuan Wang;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 11.-2017, volume: 55, issue:11, pages: 6111 - 6119
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Fast Solution Method for Stochastic Transmission Expansion Planning
Résumé:
Stochastic programming is a cost-effective approach to model the transmission expansion planning (TEP) considering the uncertainties of wind and load, which is known as stochastic TEP (STEP). The uncertainty can be accurately represented by a large number of scenarios, which need to be reduced to a relatively small number in order to shorten the computational time required by the STEP. The forward selection algorithm (FSA) is an accurate scenario reduction method which, however, is quite time consuming. An improved FSA (IFSA) is proposed in order to shorten the computational time. The STEP is a large-scale mixed-integer programming problem, and, therefore, is difficult to be solved directly. Benders decomposition algorithm is suitable to solve the STEP by decomposing it into master and multiple slave problems. The slave problems are nonlinear and thereby are difficult and time consuming to be solved. In this regard, a linearization method is proposed to solve the slave problems faster and to calculate the Lagrangian multipliers needed by the master problem. Two medium and a large datasets are used to demonstrate the efficiency of the IFSA and a 24-, a 300-, and a 2383-bus test systems are used to verify the efficiency of the linearization method.
Auteurs: Junpeng Zhan;C. Y. Chung;Alireza Zare;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 11.-2017, volume: 32, issue:6, pages: 4684 - 4695
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Fast State Estimator for Systems Including Limited Number of PMUs
Résumé:
This paper presents a fast state estimator and a corresponding bad data (BD) processing architecture aimed at improving computational efficiency and maintaining high estimation accuracy of existing state estimation (SE) algorithms, simultaneously. The conventional and phasor measurements are separately processed by a three-stage SE method and a linear estimator, respectively. Then, the derived estimates are combined using estimation fusion theory. To eliminate computational bottlenecks of the conventional BD processing scheme, BD identification is moved before the second stage of supervisory control and data acquisition based SE, and bad phasor measurements or bad conventional measurements in the phasor measurement units observable area are identified and processed all at once, which can dramatically reduce the implementation time, especially for large-scale networks with multiple BD. The proposed estimator is compared to existing methods in terms of estimation accuracy and computational effort through simulation studies conducted on standard IEEE test systems. Promising simulation results show that the proposed estimator could be an effective method to obtain system states in a fast and accurate manner.
Auteurs: Ting Wu;C. Y. Chung;Innocent Kamwa;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 11.-2017, volume: 32, issue:6, pages: 4329 - 4339
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Fern Fractal Leaf Inspired Wideband Antipodal Vivaldi Antenna for Microwave Imaging System
Résumé:
This communication presents a new approach to implement planar antipodal Vivaldi antenna design. A nature fern inspired fractal leaf structure is implemented here. Impedance bandwidth (−10 dB) of the proposed antenna is around 19.7 GHz starting from 1.3 to 20 GHz. The lower operating frequency of this antenna is reduced by 19% with the second iteration as compared to the first iteration of fractal leaf structure. The prototype antenna is fabricated and tested in frequency as well as in time domains to obtain various transfer characteristics along with common antenna parameters. Experimental results show that good wideband feature, stable radiation pattern, and promising group delay of less than 1 ns signatures are obtained, which agree well with the simulated data. The miniaturized proposed antenna structure becomes an attractive choice in microwave imaging applications because of its ultrawide fractional bandwidth at 175%, high directive gain of 10 dBi, and finally appreciably large fidelity factor above (>90%).
Auteurs: Balaka Biswas;Rowdra Ghatak;D. R. Poddar;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 6126 - 6129
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A First-Order Model of the Multiple-Feed Toroidal Magneto-Dielectric Antenna
Résumé:
A model of the input impedance of the toroidal permeable antenna, which is the dual of the conventional metal loop antenna, is derived, starting from Schelkunoff’s transmission line description of the loop antenna instead of the electrically small limit model. This antenna operates in both the monopole mode and circularly polarized dipole mode and is constructed from a torus of high permeability material. Since the ultimate goal is to obtain an impedance model from which to derive the best matching network; the input impedance is expressed in a form that has a frequency independent resistor terminating a reactive network which is called the Darlington form. Because such a circuit mimics closely the input impedance of the dipole modes of the spherical mode expansion, it is a much better model of the antennas as we go beyond the electrically small limit. The feed loop contribution is explicitly accounted for and the results are compared with fullwave simulations of a typical toroidal antenna operating in both monopole and circularly polarized dipole modes which show a good agreement well beyond the electrically small limit.
Auteurs: Tara Yousefi;Rodolfo E. Diaz;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 5796 - 5807
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Fully Integrated CMOS Fluorescence Biochip for DNA and RNA Testing
Résumé:
Design and successful implementation of a fully integrated CMOS fluorescence biochip for deoxyribonucleic acid (DNA)/ribonucleic acid (RNA) testing in molecular diagnostics (MDx) is presented. The biochip includes a $32 times 32$ array of continuous wave fluorescence detection biosensing elements. Each biosensing element is capable of having unique DNA probe sequences, wavelength-selective multi-dielectric emission filter (OD of 3.6), resistive heater for thermal cycling, and a high performance and programmable photodetector. The dimension of each biosensor is $100,,mu text {m}times 100,,mu text{m}$ with a $50 ,,mu text {m}times 50,,mu text{m},,text{N}_{mathrm {well}}$ - $text{P}_{mathrm {sub}}$ photodiode acting as the optical transducer, and a $mathrm {Sigma !Delta }$ modulator-based photocurrent sensor. The measured photodetector performance shows ~116 dB detection dynamic range (10 fA–10 nA) over the 25 °C–100 °C temperature range, while being ~1 dB away from the fundamental shot-noise limit. To empirically demonstrate the compatibility of this biochip with MDx applications, we have successfully utilized the array and its thermal cycling capability to adopt a 7-plex panel for detection of six human upper respiratory viruses.
Auteurs: Arun Manickam;Rituraj Singh;Mark W. McDermott;Nicholas Wood;Sara Bolouki;Pejman Naraghi-Arani;Kirsten A. Johnson;Robert G. Kuimelis;Gary Schoolnik;Arjang Hassibi;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 2857 - 2870
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Fully Integrated Digital Low-Dropout Regulator Based on Event-Driven Explicit Time-Coding Architecture
Résumé:
This paper presents a fully integrated digital low-dropout (LDO) voltage regulator based on event-driven control architecture. The focus of the paper is to scale the off-chip output capacitor of an LDO conventionally used to compensate fast load current change. To shrink the output capacitor size, it is paramount to shorten control latency. This can be done by employing a high-speed error amplifier in analog LDO designs and by using fast clock in digital synchronous LDO designs. However, those approaches become less suitable for sub-1-V supply voltage due to the headroom problem of analog circuits and/or increase power dissipation due to the high-frequency clock. In this paper, we tackle the tradeoff between power consumption and control latency by introducing an event-driven approach. Our event-driven approach enables to perform regulation tasks only when the output voltage deviates significantly from a set point, simultaneously achieving short latency and low-power dissipation. We prototyped an event-driven digital LDO that supports 400- $mu text{A}$ load current at 0.5-V input and 0.45-V output voltage. The measurements show 40-mV droop voltage and 96.3% peak current efficiency with an on-chip integrated 0.4-nF output capacitor.
Auteurs: Doyun Kim;Mingoo Seok;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 3071 - 3080
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Fully Serial-In Parallel-Out Digit-Level Finite Field Multiplier in $mathbb {F}_{2^{m}}$ Using Redundant Representation
Résumé:
Redundant basis (RB) is one of the appealing representation systems for finite field arithmetic due to its specific features in providing cost-free squaring operation in hardware implementation and because it eliminates the need for modular reduction. In this brief, a new architecture for digit-level finite field multiplication in $mathbb {F}_{2^{m}}$ using redundant representation is proposed. Contrary to previously presented redundant basis multipliers, in the proposed architecture one digit of each operand is concurrently fed into the multiplier at each clock cycle which, in turn, reduces the total number of the clock cycles required in the multiplication process. To draw an accurate comparison, the proposed multiplier together with several existing digit-level RB multipliers were fully implemented in 65-nm CMOS technology.
Auteurs: Parham Hosseinzadeh Namin;Roberto Muscedere;Majid Ahmadi;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 11.-2017, volume: 64, issue:11, pages: 1337 - 1341
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Game With Randomly Distributed Eavesdroppers in Wireless Ad Hoc Networks: A Secrecy EE Perspective
Résumé:
We study energy-efficient secure communication using the combined approach of game theory and stochastic geometry in a large-scale wireless network, where legitimate transmitters (Alice nodes) and eavesdroppers (Eve nodes) are randomly distributed in space. We consider the following two scenarios according to the Eve tier's strategy: I) the Eve tier activates all its nodes to maximally eavesdrop the confidential messages of the Alice tier; and II) the Eve tier activates only a portion of its nodes to maximize its energy efficiency (EE) in eavesdropping according to the Alice tier's node activation. In Scenario I, we propose an alternating optimization scheme that maximizes the secrecy EE of the Alice tier by controlling the node-activation probability, the confidential message rate, the redundancy rate, and the number of active antennas. Simulation result shows that the proposed scheme can achieve the optimal secrecy EE. In Scenario II, we study an energy-efficient node activation game between the Alice tier and the Eve tier, where the former and the latter control their node-activation probabilities to maximize the secrecy EE and the eavesdropping EE, respectively. We show that the node activation game admits a unique Nash equilibrium. The node-activation probabilities of the Alice tier and the Eve tier at the Nash equilibrium can be used to estimate their network lifetimes, which are important information for the energy-efficient secure network design. Simulation result shows that the best-response dynamics converges to the Nash equilibrium within a few iterations.
Auteurs: Younggap Kwon;Xudong Wang;Taewon Hwang;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 11.-2017, volume: 66, issue:11, pages: 9916 - 9930
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A GaN PA for 4G LTE-Advanced and 5G: Meeting the Telecommunication Needs of Various Vertical Sectors Including Automobiles, Robotics, Health Care, Factory Automation, Agriculture, Education, and More
Résumé:
The ever-increasing data rate and number of connections for mobile communication offer exciting user experiences in our everyday lives. Currently, the wireless communication frontier is shifting from the current fourth generation (4G) to the forthcoming fifth generation (5G). We expect much of society to go through a revolutionary change with the advent of the 5G era-a change that will involve not only the telecommunication industry but also a wide range of vertical sectors, including automobiles, robotics, health care, factory automation, agriculture, and education.
Auteurs: Rui Ma;Koon Hoo Teo;Shintaro Shinjo;Koji Yamanaka;Peter M. Asbeck;
Apparue dans: IEEE Microwave Magazine
Date publication: 11.-2017, volume: 18, issue:7, pages: 77 - 85
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Gastric Tube Monitoring System for Clinical Applications
Résumé:
To correctly insert a gastric tube into the stomach, the position of an attached permanent magnet is estimated by solving the inverse problem using measurement data obtained from magneto-impedance (MI) sensors placed outside the patient’s body. The ubiquity and power of tablet computers make them promising tools to easily confirm the position of the tip of the gastric tube. However, a single mobile device may be insufficient for actually solving the inverse problem. Therefore, we propose a distributed cooperative local access network system for the estimation of the position of a permanent magnet attached to the tip of a gastric tube. In addition, we evaluate whether ferromagnetic materials near a sensor affect the performance of the system. Experimental results show that the position estimation error is less than 10 mm, even when the tip is 150 mm from a MI sensor, and that the tip position can be displayed on a tablet computer every 0.25 s. These results suggest that the proposed method holds promise for hospital applications.
Auteurs: Teruyoshi Sasayama;Yuji Gotoh;Keiji Enpuku;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 4
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Generalisation of Dillon's APN Permutation With the Best Known Differential and Nonlinear Properties for All Fields of Size $2^{4k+2}$
Résumé:
The existence of almost perfect nonlinear (APN) permutations operating on an even number of variables was a long-standing open problem, until an example with six variables was exhibited by Dillon et al. in 2009. However it is still unknown whether this example can be generalized to any even number of inputs. In a recent work, Perrin et al. described an infinite family of permutations, named butterflies, operating on $(4k+2)$ variables and with differential uniformity at most 4, which contains the Dillon APN permutation. In this paper, we generalize this family, and we completely solve the two open problems raised by Perrin et al. Indeed we prove that all functions in this larger family have the best known nonlinearity. We also show that this family does not contain any APN permutation besides the Dillon permutation, implying that all other functions have differential uniformity exactly four.
Auteurs: Anne Canteaut;Sébastien Duval;Léo Perrin;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 11.-2017, volume: 63, issue:11, pages: 7575 - 7591
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Generalized Method to Extract Visual Time-Sharing Sequences From Naturalistic Driving Data
Résumé:
Indicators based on visual time-sharing have been used to investigate drivers’ visual behaviour during additional task execution. However, visual time-sharing analyses have been restricted to additional tasks with well-defined temporal start and end points and a dedicated visual target area. We introduce a method to automatically extract visual time-sharing sequences directly from eye tracking data. This facilitates investigations of systems, providing continuous information without well-defined start and end points. Furthermore, it becomes possible to investigate time-sharing behavior with other types of glance targets such as the mirrors. Time-sharing sequences are here extracted based on between-glance durations. If glances to a particular target are separated by less than a time-based threshold value, we assume that they belong to the same information intake event. Our results indicate that a 4-s threshold is appropriate. Examples derived from 12 drivers (about 100 hours of eye tracking data), collected in an on-road investigation of an in-vehicle information system, are provided to illustrate sequence-based analyses. This includes the possibility to investigate human-machine interface designs based on the number of glances in the extracted sequences, and to increase the legibility of transition matrices by deriving them from time-sharing sequences instead of single glances. More object-oriented glance behavior analyses, based on additional sensor and information fusion, are identified as the next future step. This would enable automated extraction of time-sharing sequences not only for targets fixed in the vehicle’s coordinate system, but also for environmental and traffic targets that move independently of the driver’s vehicle.
Auteurs: Christer Ahlstrom;Katja Kircher;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 11.-2017, volume: 18, issue:11, pages: 2929 - 2938
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Generative Audio-Visual Prosodic Model for Virtual Actors
Résumé:
An important problem in computer animation of virtual characters is the expression of complex mental states during conversation using the coordinated prosody of voice, rhythm, facial expressions, and head and gaze motion. In this work, the authors propose an expressive conversion method for generating natural speech and facial animation in a variety of recognizable attitudes, using neutral speech and animation as input. Their method works by automatically learning prototypical prosodic contours at the sentence level from an original dataset of dramatic attitudes.
Auteurs: Adela Barbulescu;Rémi Ronfard;Gérard Bailly;
Apparue dans: IEEE Computer Graphics and Applications
Date publication: 11.-2017, volume: 37, issue:6, pages: 40 - 51
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Generic Table Recomputation-Based Higher-Order Masking
Résumé:
Masking is a class of well-known countermeasure against side-channel attacks by employing the idea of secret sharing. In this paper, we propose a generic table recomputation-based masking scheme at any chosen order ${t}$ , named divided ${S}$ -box masking (DSM), and its security has been proved under the security framework from Crypto 2003. The table recomputation-based masking is suitable for software implementation and the masked table can be stored in memory, where it can be accessed fast. For any input, DSM scheme generates ${n}$ output shares by two queries. DSM scheme requires two vectors ${L}$ and ${R}$ , and a matrix ${M}$ of random numbers. Each element of ${L}$ is the XOR result of the output of ${S}$ -box and $ {n-1}$ random numbers. These $ {n-1}$ random numbers are stored in two lines of ${M}$ and ${R}$ which is a vector of indexes for the second query. Furthermore, we performed the attacks on the software implementation of DSM to evaluate its practical security, and compared the timing and space complexity with the existing table recomputation-based masking in the same platform to verify the adva- tage of the DSM.
Auteurs: Ming Tang;Zhenlong Qiu;Zhipeng Guo;Yi Mu;Xinyi Huang;Jean-Luc Danger;
Apparue dans: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Date publication: 11.-2017, volume: 36, issue:11, pages: 1779 - 1789
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Geometric Approach to Aggregate Flexibility Modeling of Thermostatically Controlled Loads
Résumé:
Coordinated aggregation of a large population of thermostatically controlled loads (TCLs) presents a great potential to provide various ancillary services to the grid. One of the key challenges of integrating TCLs into system-level operation and control is developing a simple and portable model to accurately capture their aggregate flexibility. In this paper, we propose a geometric approach to model the aggregate flexibility of TCLs. We show that the set of admissible power profiles of an individual TCL is a polytope, and their aggregate flexibility is the Minkowski sum of the individual polytopes. In order to represent their aggregate flexibility in an intuitive way and achieve a tractable approximation, we develop optimization-based algorithms to approximate the polytopes by the homothets of a given convex set. As a special application, this set is chosen as a virtual battery model, and the corresponding optimal approximations are solved efficiently by equivalent linear programming problems. Numerical results show that our algorithms yield significant improvement in characterizing the aggregate flexibility over existing modeling methods. We also conduct case studies to demonstrate the efficacy of our approaches by coordinating TCLs to track a frequency regulation signal from the Pennsylvania–New Jersey–Maryland Interconnection.
Auteurs: Lin Zhao;Wei Zhang;He Hao;Karanjit Kalsi;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 11.-2017, volume: 32, issue:6, pages: 4721 - 4731
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Geometric Characterization of the Persistence of Excitation Condition for the Solutions of Autonomous Systems
Résumé:
The persistence of excitation of signals generated by time-invariant, autonomous, linear, and nonlinear systems is studied using a geometric approach. A rank condition is shown to be equivalent, under certain assumptions, to the persistence of excitation of the solutions of the class of systems considered, both in the discrete-time and in the continuous-time settings. The rank condition is geometric in nature and can be checked a priori, i.e. without knowing explicitly the solutions of the system, for almost periodic systems. The significance of the ideas and tools presented is illustrated by means of simple examples. Applications to model reduction from input–output data and stability analysis of skew-symmetric systems are also discussed.
Auteurs: Alberto Padoan;Giordano Scarciotti;Alessandro Astolfi;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 11.-2017, volume: 62, issue:11, pages: 5666 - 5677
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Glimpse into the World of FinTech Accelerators?The Open Vault at OCBC
Résumé:
Financial technology (FinTech) has been garnering increased attention in recent years. The financial services industry that provides various types of financial, banking, and insurance services to customers (both individual or corporate) is showing more interest in adopting technology to innovate and grow. Technology, especially information systems, is not alien to this industry. According to the work of Garbade and Silber, telecommunication was first introduced into bank markets back in 1846. This helped reduce stock price differentials between New York and geographically dispersed regional stock markets. Similarly, the introduction of the transatlantic cable in 1866 enabled a securities trade originating from the United Kingdom and destined for the U.S. market to be completed in one day rather than the usual six.
Auteurs: Sharad Sinha;
Apparue dans: IEEE Potentials
Date publication: 11.-2017, volume: 36, issue:6, pages: 20 - 23
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Graph-Based Random Access Protocol for Crowded Massive MIMO Systems
Résumé:
To resolve intra-cell pilot collision in crowded massive multiple-input multiple-output systems, a new pilot random access protocol, called strongest-user collision resolution combined graph-based pilots access (SUCR-GBPA), is proposed. This protocol allows all failed user equipments (UEs) to randomly select a pilot from the pilots that are not selected by any UE in the initial step. By exploiting the characteristic that the channel responses between UEs and the base station are invariant within the coherence time, a bipartite graph is established where active UEs and selected pilots are considered variable nodes and factor nodes, respectively. Based on this bipartite graph, the successive interference cancellation algorithm is employed to estimate the channel response of each UE. Finally, utilizing the and-or tree principle, we analyze the performance of the proposed SUCR-GBPA protocol, including the maximum number of the tolerable active UEs, the minimum number of the required pilots, uplink throughput, and the mean-square-error performance of the SUCR-GBPA channel estimation. Simulation results demonstrate that, compared with the SUCR protocol, the proposed SUCR-GBPA protocol significantly improves the uplink throughput and provides accurate estimation on the channel response at the same time.
Auteurs: Huimei Han;Ying Li;Xudong Guo;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 11.-2017, volume: 16, issue:11, pages: 7348 - 7361
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Graphical Model for Online Auditory Scene Modulation Using EEG Evidence for Attention
Résumé:
Recent findings indicate that brain interfaces have the potential to enable attention-guided auditory scene analysis and manipulation in applications, such as hearing aids and augmented/virtual environments. Specifically, noninvasively acquired electroencephalography (EEG) signals have been demonstrated to carry some evidence regarding, which of multiple synchronous speech waveforms the subject attends to. In this paper, we demonstrate that: 1) using data- and model-driven cross-correlation features yield competitive binary auditory attention classification results with at most 20 s of EEG from 16 channels or even a single well-positioned channel; 2) a model calibrated using equal-energy speech waveforms competing for attention could perform well on estimating attention in closed-loop unbalanced-energy speech waveform situations, where the speech amplitudes are modulated by the estimated attention posterior probability distribution; 3) such a model would perform even better if it is corrected (linearly, in this instance) based on EEG evidence dependence on speech weights in the mixture; and 4) calibrating a model based on population EEG could result in acceptable performance for new individuals/users; therefore, EEG-based auditory attention classifiers may generalize across individuals, leading to reduced or eliminated calibration time and effort.
Auteurs: Marzieh Haghighi;Mohammad Moghadamfalahi;Murat Akcakaya;Barbara G. Shinn-Cunningham;Deniz Erdogmus;
Apparue dans: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Date publication: 11.-2017, volume: 25, issue:11, pages: 1970 - 1977
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Hardware Approach to Fairly Balance the Inter-Thread Interference in Shared Caches
Résumé:
Shared caches have become the common design choice in the vast majority of modern multi-core and many-core processors, since cache sharing improves throughput for a given silicon area. Sharing the cache, however, has a downside: the requests from multiple applications compete among them for cache resources, so the execution time of each application increases over isolated execution. The degree in which the performance of each application is affected by the interference becomes unpredictable yielding the system to unfairness situations. This paper proposes Fair-Progress Cache Partitioning (FPCP), a low-overhead hardware-based cache partitioning approach that addresses system fairness. FPCP reduces the interference by allocating to each application a cache partition and adjusting the partition sizes at runtime. To adjust partitions, our approach estimates during multicore execution the time each application would have taken in isolation, which is challenging. The proposed approach has two main differences over existing approaches. First, FPCP distributes cache ways incrementally, which makes the proposal less prone to estimation errors. Second, the proposed algorithm is much less costly than the state-of-the-art ASM-Cache approach. Experimental results show that, compared to ASM-Cache, FPCP reduces unfairness by 48 percent in four-application workloads and by 28 percent in eight-application workloads, without harming the performance.
Auteurs: Vicent Selfa;Julio Sahuquillo;Salvador Petit;María E. Gómez;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 11.-2017, volume: 28, issue:11, pages: 3021 - 3032
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Head Cleaning Procedure for Heat-Assisted Magnetic Recording
Résumé:
In the heat-assisted magnetic recording (HAMR), write-induced head contamination covering the near-field transducer (NFT) can affect the transmission efficiency of optical energy from the NFT to a recording medium. We have experimentally confirmed that write performances such as data track width and signal amplitude change as a function of elapsed write time due to accumulation of the write-induced head contamination. Unintended changes of write performances in a drive can lose the capability to perform magnetic recordings as requested by a host. Here, we introduce the head cleaning procedure which removes the contamination from the interfacing surface of the head by placing it in close proximity to a disk surface. Effectiveness of the cleaning operation for performance stabilization is demonstrated with integrated HAMR drives. Detrimental effects of the mechanical cleaning operation on both head and media reliabilities have not been observed.
Auteurs: Jun Aoyama;Masaru Furukawa;Shuji Nishida;Kenji Tasaka;Kouji Matsuda;Kenji Kuroki;Masaomi Ikeda;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 4
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A High Force Density HTS Tubular Vernier Machine
Résumé:
In this paper, a high force density, high-temperature superconductor dual-stator tubular Vernier machine (HTS-DSTVM) has been proposed for wave energy extraction. The machine adopts dual-stator configuration with spoke-type permanent magnets on the translator. The inner stator does not have any winding, and HTS bulks are placed between the adjacent flux modulation teeth of the inner stator to decrease the leakage flux and improve the force density. The HTS bulks effectively shield the leakage flux of the proposed HTS-DSTVM to improve the force density and power factor. 2-D finite-element method results validate that the proposed HTS-DSTVM yields a higher thrust force density per magnet volume and higher power factor compared with the recently presented flat dual-stator spoke-type linear Vernier machine due to the leakage flux shielding effect of HTS bulks.
Auteurs: Noman Baloch;Salman Khaliq;Byung-Il Kwon;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 5
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A High School Team’s Hard Road to Success in an International Engineering Competition
Résumé:
A team of New Jersey high school sophomores took part in a well-known international underwater-vehicle competition this year. The team members discuss their arduous journey as they designed and built a vehicle that then had to undertake several challenging tasks.
Auteurs: Daniel Lam;Ethan Stillman;Anthony Cariello;Andrew McCorkle;Ahmed Fouad;
Apparue dans: Computer
Date publication: 11.-2017, volume: 50, issue:11, pages: 68 - 71
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A High-PDE, Backside-Illuminated SPAD in 65/40-nm 3D IC CMOS Pixel With Cascoded Passive Quenching and Active Recharge
Résumé:
We present a complete pixel based on a single-photon avalanche diode (SPAD) fabricated in a backside-illuminated (BSI) 3D IC technology. The chip stack comprises an image sensing tier produced in a 65-nm image sensor technology and a data processing tier in 40-nm CMOS. Using a simple, CMOS-compatible technique, the pixel is capable of passive quenching and active recharge at voltages well above those imposed by a single transistor whilst ensuring that the reliability limits across the gate-source ( $text {V} _{text {GS}}$ ), gate-drain ( $text {V} _{text {GD}}$ ) and drain–source ( $text {V} _{text {DS}}$ ) are not exceeded for any device. For a given technology, the circuit extends the maximum excess bias that SPADs can be operated at when using transistors as quenching elements, thus improving the SPAD sensitivity, timing performance, and photon detection probability uniformity. Implemented with 2.5-V thick oxide transistors and operated at 4.4-V excess bias, the design achieves a timing jitter of 95-ps full-width at half maximum, maximum photon detection efficiency (PDE) of 21.9% at 660 nm and 0.08% afterpulsing probability with a dead time of 8 ns. This is both the lowest afterpulsing probability at 8-ns dead time and the highest peak PDE for a BSI SPAD in a 3D IC technology to date.
Auteurs: Scott Lindner;Sara Pellegrini;Yann Henrion;Bruce Rae;Martin Wolf;Edoardo Charbon;
Apparue dans: IEEE Electron Device Letters
Date publication: 11.-2017, volume: 38, issue:11, pages: 1547 - 1550
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A High-Voltage-Enabled Class-D Polar PA Using Interactive AM-AM Modulation, Dynamic Matching, and Power-Gating for Average PAE Enhancement
Résumé:
This paper describes a 2.4-GHz digitally-modulated class-D polar power amplifier (PA) with novel circuit techniques to enhance the average power-added efficiency (PAEave) that becomes increasingly crucial to prolong the battery lifetime. The PA features 5+5-b interactive AM-AM modulation between the class-D unit amplifiers and a novel high resolution dynamic matching network (DMN) to improve the back-off PAE. A novel power-gating technique tailored for class-D PAs is also proposed and embedded into each unit amplifier and its driver (tapped inverter chain), alleviating leakage-current suppression, area reduction of the DMN, and direct-powering by a standard 1.5-V AA battery. An high back-off power efficiency is made possible by introducing a multi-bit capacitively-tuned DMN, which adds low loss while improving the PAE of the unit amplifiers using the load-pull optimization. The DMN also can correct the antenna impedance mismatch for better average Pout (Pout,ave) and PAEave under a practical VSWR (2.5:1), and aids to reconfigure the PA between the Pout-optimized and the PAE-optimized modes. For a 20-MHz 64-QAM OFDM output at a typical EVM (< −25 dB), the 65-nm CMOS PA exhibits 40.7% PAEave at a 16.3-dBm Pout. The mode switching is demonstrated as a prospective function for battery lifetime extension.
Auteurs: Wei-Han Yu;Xingqiang Peng;Pui-In Mak;Rui P. Martins;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 11.-2017, volume: 64, issue:11, pages: 2844 - 2857
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Highly Integrated Conjoined Single Shot Switch and Exploding Foil Initiator Chip Based on MEMS Technology
Résumé:
In this letter, a highly integrated conjoined device, single shot switch and an exploding foil initiator (S3-EFI) chip, was fabricated with microelectromechanical system scale fabrication methods. Photon Doppler velocimetry was utilized to characterize the behavior of the flyer at firing voltages ranging from 1.00 to 2.40 kV. Electrical characterizations were then performed on the chip to obtain some fundamental parameters, such as current and voltage, and a peak current of 1.73 kA was observed at 1.50 kV. Moreover, ultrafine hexanitrostilbene pellets were detonated over firing voltage range 1.80–1.40 kV. These results demonstrate the feasibility of the chip and pave the way to the non-lead high-voltage discharge circuit. To the best of our knowledge, this is the first time to integrate exploding foil initiator with a high-voltage switch.
Auteurs: Cong Xu;Peng Zhu;Kai Chen;Wei Zhang;Ruiqi Shen;Yinghua Ye;
Apparue dans: IEEE Electron Device Letters
Date publication: 11.-2017, volume: 38, issue:11, pages: 1610 - 1613
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Hybrid Subpixel Mapping Framework for Hyperspectral Images Using Collaborative Representation
Résumé:
Subpixel mapping with a low-resolution hyperspectral image as the only input is widely applicable due to the fact that auxiliary image is not always available in practice. In this paper, the collaborative representation-based subpixel mapping (CRSPM) framework is proposed to acquire an improved classification map at subpixel scale with only a low-resolution hyperspectral image available. To efficiently extract and utilize spatial information in this case without auxiliary image, the low-resolution hyperspectral (LHS) image is processed in a hybrid framework in two different ways to generate two subpixel scale classification maps. One is obtained by classifying the upsampled LHS image using collaborative representation-based (CR-based) classifier. The other is available using CR-based classification combined with spectral unmixing and subpixel spatial attraction model. Specifically, to enclose the contextual spatial information for higher classification accuracy, a spatially joint as well as post-partitioning CR-based classifier, JCRT-based classifier, is proposed and applied in this work. To achieve better classification performance, decision fusion is applied to determine class label from the two classification maps for each subpixel by the voting of the neighboring subpixels. Experimental results illustrate that the proposed CRSPM approach clearly outperforms some state-of-the-art subpixel mapping approaches by producing smoother classification map with less misclassification.
Auteurs: Yifan Zhang;Xiaoqin Xue;Ting Wang;Mingyi He;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 11.-2017, volume: 10, issue:11, pages: 5073 - 5086
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Hybrid-Excited Vernier Permanent Magnet Machine Using Homopolar Topology
Résumé:
In this paper, a hybrid-excited vernier permanent magnet (PM) machine is proposed. Two excitation sources, namely, the PM excitation and the electrical excitation are artfully combined together based on the homopolar topology, resulting in a parallel hybrid excitation. The flux regulation capability of the proposed machine is discussed and analyzed. Unlike other hybrid-excited machines, the flux regulation is realized based on the variation of the armature flux linkage rather than directly adjusting the air-gap flux. Performances of the bi-directional flux regulation are evaluated by the 3-D finite-element method. In order to verify the analytical results, the proposed machine is prototyped and tested as a generator. Both no-load and on-load performances are assessed. The experimental results agree well with the analytical ones.
Auteurs: Wenlong Li;T. W. Ching;K. T. Chau;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 7
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Hysteretic Switched-Capacitor DC–DC Converter With Optimal Output Ripple and Fast Transient Response
Résumé:
Hysteretic control is popular for switched-capacitor (SC) dc–dc converters. Conventional hysteretic controllers require either a large output capacitor or high-speed output voltage detection for proper regulation. In this paper, a lower boundary hysteretic control method is proposed which matches the output sampling frequency to the converter switching frequency across the entire load range, hence optimal output voltage ripple can be achieved. The converter responses instantly to step-up load transients that are smaller than six times the initial load current. When larger load transient step occurs, the sampling frequency jumps to its maximum value to recover the output voltage quickly. Small output voltage droop can be achieved while using an output capacitance value on the same order as the converter’s charge transferring capacitance. A 1/2 step-down SC dc–dc converter with the proposed control technique is fabricated in 0.18- $mu text{m}$ CMOS process. The converter achieves a peak efficiency of 86.4% and delivers a maximum output power of 5 mW.
Auteurs: Zhekai Xiao;Anh Khoa Bui;Liter Siek;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 11.-2017, volume: 25, issue:11, pages: 2995 - 3005
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Ka-Band Waveguide Magic-T With Coplanar Arms Using Ridge-Waveguide Transition
Résumé:
A Ka-band waveguide magic-T with coplanar arms is presented in this letter. By using an E-plane power divider and a ridge-waveguide transition, the four arms of the magic-T are placed in the same plane, which greatly simplifies the assembly. Compared to the previous method utilizing a microstrip-to-waveguide transition, the structure proposed in this letter achieved a higher power-handling capability because of all-metal elements. Over the frequency band of 28 to 36 GHz, the measured return loss of the input port and the isolation between the opposite ports are greater than 20 dB, indicating good characteristics of the proposed structure.
Auteurs: Yin-Jian He;Da-Yi Mo;Qiong-Sen Wu;Qing-Xin Chu;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 11.-2017, volume: 27, issue:11, pages: 965 - 967
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Kernel-Based Low-Rank (KLR) Model for Low-Dimensional Manifold Recovery in Highly Accelerated Dynamic MRI
Résumé:
While many low rank and sparsity-based approaches have been developed for accelerated dynamic magnetic resonance imaging (dMRI), they all use low rankness or sparsity in input space, overlooking the intrinsic nonlinear correlation in most dMRI data. In this paper, we propose a kernel-based framework to allow nonlinear manifold models in reconstruction from sub-Nyquist data. Within this framework, many existing algorithms can be extended to kernel framework with nonlinear models. In particular, we have developed a novel algorithm with a kernel-based low-rank model generalizing the conventional low rank formulation. The algorithm consists of manifold learning using kernel, low rank enforcement in feature space, and preimaging with data consistency. Extensive simulation and experiment results show that the proposed method surpasses the conventional low-rank-modeled approaches for dMRI.
Auteurs: Ukash Nakarmi;Yanhua Wang;Jingyuan Lyu;Dong Liang;Leslie Ying;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 11.-2017, volume: 36, issue:11, pages: 2297 - 2307
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Kernel-Power-Density-Based Algorithm for Channel Multipath Components Clustering
Résumé:
Cluster-based channel modeling has been an important trend in the development of channel model, as it maintains accuracy while reducing complexity. Whereas a large number of channel measurements have shown that multipath components (MPCs) are distributed as groups, i.e., clusters, existing clustering algorithms have various drawbacks with respect to complexity, threshold choices, and/or assumptions about prior knowledge. In this paper, a kernel-power-density (KPD)-based algorithm is proposed for MPC clustering. It uses the kernel density of MPCs to incorporate the modeled behavior of MPCs and takes into account the power of the MPCs. Furthermore, the KPD algorithm only considers the $K$ nearest MPCs in the density estimation to better identify the local density variations of MPCs. A heuristic approach of cluster merging is used to improve the performance. Both simulation and channel measurements validate the KPD algorithm, and almost no performance degradation is found even with a large number of clusters and large cluster angular spread, which outperforming other algorithms. The KPD algorithm enables applications in multiple-input-multiple-output channels with no prior knowledge about the clusters, such as number and initial locations. It also has a fairly low computational complexity and can be used for cluster-based channel modeling.
Auteurs: Ruisi He;Qingyong Li;Bo Ai;Yang Li-Ao Geng;Andreas F. Molisch;Vinod Kristem;Zhangdui Zhong;Jian Yu;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 11.-2017, volume: 16, issue:11, pages: 7138 - 7151
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Large-Scale Emulation System for Realistic Three-Dimensional (3-D) Forest Simulation
Résumé:
The realistic reconstruction and radiometric simulation of a large-scale three-dimensional (3-D) forest scene have potential applications in remote sensing. Although many 3-D radiative transfer models concerning forest canopy have been developed, they mainly focused on homogeneous or relatively small heterogeneous scenes, which are not compatible with the coarse-resolution remote sensing observations. Due to the huge complexity of forests and the inefficiency of collecting precise 3-D data of large areas, realistic simulation over large-scale forest area remains challenging, especially in regions of complex terrain. In this study, a large-scale emulation system for realistic 3-D forest Simulation is proposed. The 3-D forest scene is constructed from a representative single tree database (SDB) and airborne laser scanning (ALS) data. ALS data are used to extract tree height, crown diameter and position, which are linked to the individual trees in SDB. To simulate the radiometric properties of the reconstructed scene, a radiative transfer model based on a parallelized ray-tracing code was developed. This model has been validated with an abstract and an actual 3-D scene from the radiation transfer model intercomparison website and it showed comparable results with other models. Finally, a 1 km $times$ 1 km scene with more than 100 000 realistic individual trees was reconstructed and a Landsat-like reflectance image was simulated, which kept the same spatial pattern as the actual Landsat 8 image.
Auteurs: Jianbo Qi;Donghui Xie;Dashuai Guo;Guangjian Yan;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 11.-2017, volume: 10, issue:11, pages: 4834 - 4843
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Level-Set-Based Image Assimilation Method: Potential Applications for Predicting the Movement of Oil Spills
Résumé:
In this paper, we present a novel method for assimilating geometric information from observed images. Image assimilation technology fully utilizes structural information from the dynamics of the images to retrieve the state of a system and thus to better predict its evolution. Level-set method describing the evolution of the geometry shapes of a given system is taken into account to include the dynamics of the images. This method takes advantage of Lagrangian information in an Eulerian numerical framework. In our numerical experiments, we apply this state-of-the-art technique to a pollutant transport problem, to calibrate the initial contours of pollutants and to identify diffusion coefficients of the model. It can be shown a potential approach for oil spills, because topological merging and breaking of oil slicks are well defined and easily performed by this proposed approach. Numerical results show that the proposed method is visibly efficient compared with the classical method based on the concentration map when the concentration measurements and the background fields are not well available.
Auteurs: Long Li;François-Xavier Le Dimet;Jianwei Ma;Arthur Vidard;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 11.-2017, volume: 55, issue:11, pages: 6330 - 6343
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Lightweight Masked AES Implementation for Securing IoT Against CPA Attacks
Résumé:
A false key-based advanced encryption standard (AES) technique is proposed to prevent the stored secret key leaking from the substitution-box under correlation power analysis (CPA) attacks without significant power and area overhead. Wave dynamic differential logic (WDDL)-based XOR gates are utilized during the reconstruction stage to hide the intermediate data that may be highly correlated with the false key. After applying the false key and designing the reconstruction stage with the WDDL, the minimum measurement-to-disclose value for the proposed lightweight masked AES engine implementation becomes over 150 million against CPA attacks. As compared to an unprotected AES engine, the power, area, and performance overhead of the proposed AES implementation is negligible.
Auteurs: Weize Yu;Selçuk Köse;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 11.-2017, volume: 64, issue:11, pages: 2934 - 2944
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Line Flow Granular Computing Approach for Economic Dispatch With Line Constraints
Résumé:
Line flow calculation plays a critically important role to guarantee the stable operation of power system in economic dispatch (ED) problems with line constraints. This paper presents a line flow granular computing approach for power flow calculation to assist the investigation on ED with line constraints, where the hierarchy method is adopted to divide the power network into multiple layers to reduce computational complexity. Each layer contains granules for granular computing, and the layer network is reduced by Ward equivalent retaining the PV nodes and boundary nodes of tie lines to decrease the data dimension. Then, Newton–Raphson method is applied further to calculate the power line flows within the layer. This approach is tested on IEEE 39-bus and 118-bus systems. The testing results show that the granular computing approach can solve the line flow problem in 9.2 s for the IEEE 118-bus system, while the conventional AC method needs 44.56 s. The maximum relative error of the granular computing approach in line flow tests is only 0.43%, which is quite small and acceptable. Therefore, the case studies demonstrate that the proposed granular computing approach is correct, effective, and can ensure the accuracy and efficiency of power line flow calculation.
Auteurs: Xueping Li;Liangxing Fang;Zhigang Lu;Jiangfeng Zhang;Hao Zhao;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 11.-2017, volume: 32, issue:6, pages: 4832 - 4842
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Link Between CBRAM Performances and Material Microscopic Properties Based on Electrical Characterization and Atomistic Simulations
Résumé:
In this paper, we investigate the link between various resistive memory (RRAM) electrical characteristics: endurance, window margin (WM), and retention. For this purpose, several RRAMs are characterized using various resistive layers and bottom electrodes. By focusing on one technology and optimizing programming conditions (current, voltage, and time), we establish a tradeoff between endurance and WM. Then, by changing memory stack, we demonstrate the correlation between endurance plus window marging improvement and retention degradation. Studying this last feature from a material point of view, we analyze different oxides by density functional theory. We realize a systematic review for possible exchanges of species between resistive layer and Cu-based top electrode and study their diffusion. This provides insights on conductive filament composition in different stacks. Combining previous experiments and simulations, we propose a link between memory characteristics and material microscopic parameters, through the ion energy migration barrier. Finally, we extract how endurance, WM, and retention are correlated to material properties and electrical parameters in order to choose the suitable material for a defined application using the RRAM technology.
Auteurs: Cécile Nail;Gabriel Molas;Philippe Blaise;Benoit Sklenard;Remy Berthier;Mathieu Bernard;Luca Perniola;Gérard Ghibaudo;Christophe Vallée;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 11.-2017, volume: 64, issue:11, pages: 4479 - 4485
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Low Area Overhead NBTI/PBTI Sensor for SRAM Memories
Résumé:
Bias temperature instability (BTI) is known as one serious reliability concern in nanoscale technologies. BTI gradually increases the absolute value of threshold voltage ( $V_{mathrm{ th}}$ ) of MOS transistors. The main consequence of $V_{mathrm{ th}}$ shift of the SRAM cell transistors is the static noise margin (SNM) degradation. The SNM degradation of SRAM cells results in bit-flip occurrences due to transient faults and should be monitored accurately. This paper proposes a sensor called write current-based BTI sensor (WCBS) to assess the BTI-aging state of SRAM cells. The WCBS measures BTI-induced SNM degradation of SRAM cells by monitoring the maximum write current shifts due to BTI. The observations show that the maximum current consumption during write operation is an effective identifier to measure $V_{mathrm{ th}}$ and SNM shifts. The granularity of BTI assessment of one cell up to a row of memory can be achieved by writing special bit patterns on the memory block during the test. We evaluated the sensor through SPICE-level simulations in 32-nm technology size. The precision of WCBS is about ±1.25 mV (±3.2% error). One sensor is enough for the entire SRAM memory block with negligible area/power overhead; less than 1%. The effects of process variation and temperature changes on WCBS are investigated in detail.
Auteurs: Maryam Karimi;Nezam Rohbani;Seyed-Ghassem Miremadi;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 11.-2017, volume: 25, issue:11, pages: 3138 - 3151
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Low Turn-Off Loss 4H-SiC Trench IGBT With Schottky Contact in the Collector Side
Résumé:
In this paper, a 4H-SiC trench insulated gate bipolar transistor (IGBT) incorporating a Schottky contact in the collector side is proposed to reduce the turn-off energy loss. The proposed structure is explored and compared with the conventional IGBT using ATLAS. The simulation results have indicated that the reduction in turn-off energy loss is more than 88%, with a slight degradation in the ${I}$ ${V}$ characteristics. Concurrently, with the same on-state voltage drop, the turn-off loss is reduced by a figure of 84%.
Auteurs: Yan-Juan Liu;Ying Wang;Yue Hao;Jun-Peng Fang;Chan Shan;Fei Cao;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 11.-2017, volume: 64, issue:11, pages: 4575 - 4580
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Low-Cost Lane-Determination System Using GNSS/IMU Fusion and HMM-Based Multistage Map Matching
Résumé:
This paper presents a low-cost real-time lane-determination system that fuses micro-electromechanical systems inertial sensors (accelerometers and gyroscopes), global navigation satellite system (GNSS), and commercially available road network maps. The system can be used for intelligent transportation systems, telematics applications, and autonomous driving. The system does not depend on visual markings or highly precise GNSS technology, such as DGPS or RTK, and it does not need explicit lane-level resolution maps. High-resolution estimation of the vehicle’s position, velocity, and orientation is implemented by fusing inertial sensors with GNSS in a loosely coupled mode using extended Kalman filter. A curve-to-curve road-level map-matching is implemented using a hidden Markov model followed by a least-square regression step that estimates the vehicle’s lane. The system includes a lane-change detector based on inertial sensors and the filtered vehicle’s state. The system has been realized in real time and tested extensively on real-road data. Experiments showed robust map-matching in challenging road intersections and a 97.14% lane-determination success rate.
Auteurs: Mohamed Maher Atia;Allaa R. Hilal;Clive Stellings;Eric Hartwell;Jason Toonstra;William B. Miners;Otman A. Basir;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 11.-2017, volume: 18, issue:11, pages: 3027 - 3037
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Low-Energy Machine-Learning Classifier Based on Clocked Comparators for Direct Inference on Analog Sensors
Résumé:
This paper presents a system, where clocked comparators consuming only $CV^{2}$ energy directly derive classification decisions from analog sensor signals, thereby replacing instrumentation amplifiers, ADCs, and digital MACs, as typically required. A machine-learning algorithm for training the classifier is presented, which enables circuit non-idealities as well as severe energy/area scaling in analog circuits to be overcome. Furthermore, a noise model of the system is presented and experimentally verified, providing a means to predict and optimize classification error probability in a given application. The noise model shows that superior noise efficiency is achieved by the comparator-based system compared with a system based on linear low-noise amplifiers. A prototype in 130-nm CMOS performs image recognition of handwritten numerical digits, by taking raw analog pixels as the inputs. Due to pin limitations on the chip, the images with $28times 28=784$ pixels are resized and downsampled to give 47 pixel features, yielding an accuracy of 90% for an ideal ten-way classification system (MATLAB simulated). The prototype comparator-based system achieves equivalent performance with a total energy of 543 pJ per ten-way classification at a rate up to 1.3 M images per second, representing $33times $ lower energy than an ADC/digital-MAC system.
Auteurs: Zhuo Wang;Naveen Verma;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 11.-2017, volume: 64, issue:11, pages: 2954 - 2965
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Low-Power CMOS Crystal Oscillator Using a Stacked-Amplifier Architecture
Résumé:
This paper presents a low-power 39.25-MHz crystal oscillator with a new stacked-amplifier architecture achieving the smallest figure of merit (FoM) ever reported for a crystal oscillator for wireless communications. Theoretical analyses of the power consumption and the phase noise (PN) in the proposed stacked-amplifier architecture are newly provided to clarify the reason why the proposed stacked-amplifier architecture achieves the smallest FoM. Additionally, a new self-forward-body-biasing technique and flicker noise suppression technique are shown to reduce the minimum operational supply voltage (VDD(MIN)) and the PN, respectively. The proposed 3.3-V, 39.25-MHz stacked-amplifier crystal oscillator fabricated in a 65-nm CMOS process exhibits the smallest FoM for a crystal oscillator of −248 dBc/Hz with a power consumption of 19 $mu text{W}$ and PN of −139 dBc/Hz at 1-kHz offset frequency. The relative frequency errors among 11 samples at temperatures of −30 °C to 80 °C and for ±10% supply voltage variation are ±10.5 ppm and ±0.12 ppm, respectively. The long-term frequency error is −0.98 ppm in the first year (=365 days).
Auteurs: Shunta Iguchi;Takayasu Sakurai;Makoto Takamiya;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 3006 - 3017
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Low-Power High-Speed Hybrid ADC With Merged Sample-and-Hold and DAC Functions for Efficient Subranging Time-Interleaved Operation
Résumé:
An 8-bit 1-GS/s hybrid analog-to-digital converter (ADC) for high-speed low-power applications is introduced. It has a subranging architecture with a 3-bit flash ADC as a first stage and a 5-bit four-channel time-interleaved comparator-based asynchronous binary search (CABS) ADC as a second stage. In each channel, a merged sample-and-hold and capacitive digital-to-analog converter (SHDAC) performs the sampling and residue generation for the subranging operation. The effects of the parasitic capacitances on the SHDAC linearity are analyzed, and a linearity correction method is introduced to enable power-efficient high-speed operation in the presence of parasitics because the design approach allows reducing the sampling capacitance in the SHDAC. Furthermore, the sampling network configuration incorporates an error reduction technique to alleviate the clock feedthrough of bootstrap switches. The offsets of the comparators in the flash ADC are calibrated using a built-in reference signal via an extra sampling channel. According to postlayout simulations at 1 GS/s in 130-nm CMOS, the ADC has an effective number of bits higher than 7.37 bits up to the Nyquist frequency while consuming 13.3 mW from a 1.2-V supply.
Auteurs: Seyed Alireza Zahrai;Marina Zlochisti;Nicolas Le Dortz;Marvin Onabajo;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 11.-2017, volume: 25, issue:11, pages: 3193 - 3206
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Low-Profile Wideband Substrate-Integrated Waveguide Cavity-Backed E-Shaped Patch Antenna for the Q-LINKPAN Applications
Résumé:
A low-profile substrate-integrated waveguide cavity-backed E-shaped patch antenna is proposed for the Q-LINKPAN application in this paper. In order to expand the operating bandwidth, a co-planar waveguide (CPW) is used to feed the proposed antenna with a metallized via for generating one more resonant mode. In addition, a substrate-integrated cavity is employed to suppress the surface wave and improve the radiation efficiency. A differential feeding network is used in the design to improve the symmetry of the E-plane radiation pattern and the H-plane cross polarization. A $2 times 2$ prototype is designed, fabricated, and measured for a demonstration. The measured results show that the prototype has a 10 dB impedance bandwidth of 34.4%, a gain of around 12.5 dBi with a narrow E-plane radiation beam within 37.5–46 GHz for long distance applications, and a gain of around 8 dBi with a broad E-plane radiation beam within 47–53 GHz for short distance applications. The proposed technique can be used to develop compact planar antenna for meeting both the short- and long-rang communication requirements of the emerging Q-LINKPAN wireless system.
Auteurs: Kuikui Fan;Zhang-Cheng Hao;Quan Yuan;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 5667 - 5676
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Machine Learning-Based ETA Estimator for Wi-Fi Transmissions
Résumé:
Recent advancements related to device to device (D2D) communication make it possible for a transmitting node to dynamically select the interface to be used for data transfers locally, without traversing any network infrastructure. In this scenario, a controller is identified, whose goal is to manage the D2D connection after its establishment. The software defined networking paradigm makes it possible to select this controller node via software: a device becomes the master node of a Wi-Fi-direct network, whereas the remaining units, i.e., the clients, can exchange data with other devices through the master. This paper develops a machine learning-based prediction algorithm for the aforementioned scenario, in which multiple elements, while receiving data from the controller, require an accurate on-the-fly estimation of the remaining transmission time, i.e., the estimated time of arrival. Different machine learning approaches are considered for this task, with the goal of exploiting only the information available at each client, without modifying any standard communication protocol. This information is critical when, for instance, a mobile user needs to decide whether or not to delay a data transfer, based on the load of the network and on the residual time under radio coverage from an access point.
Auteurs: Davide Del Testa;Matteo Danieletto;Michele Zorzi;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 11.-2017, volume: 16, issue:11, pages: 7011 - 7024
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Major Player: Renewables Are Now Mainstream [Guest Editorial]
Résumé:
The Utility Variable-Generation Integration Group (UVIG) has focused on the integration of wind, and more recently solar, power into electric power systems. The industry focus is now concentrating around how to integrate inverter-based power plants into weak grids and, indeed, how to design a grid for 100% nonsynchronous generation. The focus is no longer on how to integrate those alien forms of generation from Mars into the grid but how to integrate the energy systems of the future, of which renewable energy systems are a major part, into a coherent whole. Examines how this will likely develop over the coming years.
Auteurs: J. Charles Smith;
Apparue dans: IEEE Power and Energy Magazine
Date publication: 11.-2017, volume: 15, issue:6, pages: 16 - 21
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Method for Accurate Parameter Estimation of Series Compensated Transmission Lines Using Synchronized Data
Résumé:
Power system software used for analysis and dynamic simulation and relay settings require accurate model parameters of different elements for precise results. For this, transmission line parameter verification is necessary at times, which changes due to atmospheric condition and aging. This paper presents a method for estimating the parameters of series compensated line online using synchronized time-domain data captured by the intelligent electronic devices at both ends of the line, which is free of the compensation model. The method uses traveling waves generated during disturbance to obtain the propagation constant of the line, which is used to estimate the resistance and the characteristic impedance of the line. Subsequently, the inductance and capacitance of the line are calculated. The proposed method is tested using PSCAD/EMTDC simulation data of an actual series compensated line in Indian power grid. Results demonstrate the accuracy of the proposed method.
Auteurs: Swaroop Gajare;Ashok Kumar Pradhan;Vladimir Terzija;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 11.-2017, volume: 32, issue:6, pages: 4843 - 4850
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Mid-Infrared Fiber-Coupled QEPAS Nitric Oxide Sensor for Real-Time Engine Exhaust Monitoring
Résumé:
We report the development and application of a compact and sensitive mid-infrared nitric oxide (NO) sensor using off-beam quartz-enhanced photoacoustic spectroscopy (QEPAS). This QEPAS sensor exploits the strong absorption band of NO at $5.2~ mu text{m}$ using a distributed-feedback quantum cascade laser (QCL). The QCL was connected with the custom-designed photoacoustic gas cell with a mid-infrared multimode fiber to form a plug-and-play system. The selection of key sensor parameters, such as micro-resonator, laser modulation depth, and gas pressure, was discussed in detail about improving the detection sensitivity. With a minimum detection limit of 120 ppbv, our QEPAS NO sensor was deployed in real-time diesel-engine exhaust monitoring. We observed the influence of soot existing in the engine exhaust on the sensor performance, which was filtered by a high efficiency particulate arrestance material. Our sensor captured the varied NO concentrations between 126 and 187 ppmv in the exhaust at different engine rotational speeds.
Auteurs: Chao Shi;Dien Wang;Zhen Wang;Liuhao Ma;Qiang Wang;Ke Xu;Shih-Chi Chen;Wei Ren;
Apparue dans: IEEE Sensors Journal
Date publication: 11.-2017, volume: 17, issue:22, pages: 7418 - 7424
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Miniaturized Force Sensor Based on Hair-Like Flexible Magnetized Cylinders Deposited Over a Giant Magnetoresistive Sensor
Résumé:
The detection of force with higher resolution than observed in humans (~1 mN) is of great interest for emerging technologies, especially surgical robots, since this level of resolution could allow these devices to operate in extremely sensitive environments without harming these. In this paper, we present a force sensor fabricated with a miniaturized footprint (9 mm2), based on the detection of the magnetic field generated by magnetized flexible pillars over a giant magnetoresistive sensor. When these flexible pillars deflect due to external loads, the stray field emitted by these will change, thus varying the GMR sensor resistance. A sensor with an array of five pillars with $200~mu text{m}$ diameter and 1 mm height was fabricated, achieving a 0 to 26 mN measurement range and capable of detecting a minimum force feature of $630~mu text{N}$ . A simulation model to predict the distribution of magnetic field generated by the flexible pillars on the sensitive area of the GMR sensor in function of the applied force was developed and validated against the experimental results reported in this paper. The sensor was finally tested as a texture classification system, with the ability of differentiating between four distinct surfaces varying between 0 and $162~mu text{m}$ root mean square surface roughness.
Auteurs: Pedro Ribeiro;Mohammed Asadullah Khan;Ahmed Alfadhel;Jürgen Kosel;Fernando Franco;Susana Cardoso;Alexandre Bernardino;José Santos-Victor;Lorenzo Jamone;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 5
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A More National Technology
Résumé:
Over the past several decades, many computer societies have begun to focus on IT, leaving computer science behind.
Auteurs: David Alan Grier;
Apparue dans: Computer
Date publication: 11.-2017, volume: 50, issue:11, pages: 77 - 77
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Multi-Objective Routing Strategy for QoS and Energy Awareness in Software-Defined Networks
Résumé:
Energy consumption is a key concern in the deployment and operation of current data networks, for which software-defined networks (SDNs) have become a promising alternative. Although several works have been proposed to improve the energy efficiency, these techniques may lead to performance degradations when QoS requirements are neglected. Inspired by this problem, this letter introduces a new routing strategy, jointly considering QoS requirements and energy awareness in SDN with in-band control traffic. To that end, we present a complete formulation of the optimization problem and implement a multi-objective evolutionary algorithm. Simulation results validate the performance improvement on critical network parameters.
Auteurs: Adriana Fernández-Fernández;Cristina Cervelló-Pastor;Leonardo Ochoa-Aday;
Apparue dans: IEEE Communications Letters
Date publication: 11.-2017, volume: 21, issue:11, pages: 2416 - 2419
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Multi-Platform Lab for Teaching and Research in Active Distribution Networks
Résumé:
Today's electricity paradigm requires that the notion of active distribution systems be introduced at both undergraduate and graduate curricula. This involves not only the customary theoretical foundations but also a suitable power engineering laboratory, where flexible enough and affordable resources allow students and researchers to carry out hands-on experiments reinforcing the concepts explained in the classroom. This paper describes the smart grid laboratory of the Power Engineering Group at the University of Seville, composed of a scaled-down distribution system, along with the required control and monitoring equipment, designed to help its users easily grasp the major influence that distributed generation and storage devices exert in the operation of medium-voltage distribution systems.
Auteurs: José María Maza-Ortega;Manuel Barragán-Villarejo;Francisco de Paula García-López;Juan Jiménez;Juan Manuel Mauricio;Lázaro Alvarado-Barrios;Antonio Gómez-Expósito;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 11.-2017, volume: 32, issue:6, pages: 4861 - 4870
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Multispectral 3-D Vision System for Invertebrate Detection on Crops
Résumé:
Real-time detection and identification of invertebrates on crops is a necessary capability for integrated pest management, however, this challenging task has not been well-solved. Multispectral or hyperspectral machine vision systems have shown advantages for efficient and accurate detection and identification of certain invertebrate pests. However, only using spectral information has limited the capability for detection, especially for some camouflaged pests on host plants. Three-dimensional (3-D) object representations are being intensively studied for multiview object recognition and scene understanding in many fields. However, because of the lack of proper data collection methods and robust algorithms, 3-D technologies have not yet attained applications for detecting invertebrates. We have developed a multispectral 3-D vision system, which can create denser point clouds of plants and pests using the multispectral images of ultraviolet, blue, green, red, and near-infrared. An algorithm named local variance of normals was designed, which can distinguish broad leaves from relatively larger pests in noisy point clouds. The vision system could aid integrated pest management systems for pest monitoring, or could be used as a sensor of an automatic pesticide sprayer.
Auteurs: Huajian Liu;Sang-Heon Lee;Javaan Singh Chahl;
Apparue dans: IEEE Sensors Journal
Date publication: 11.-2017, volume: 17, issue:22, pages: 7502 - 7515
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Approach for Detecting Urban Centers and Their Spatial Structure With Nighttime Light Remote Sensing
Résumé:
Urban spatial structure affects many aspects of urban functions and has implications for accessibility, environmental sustainability, and public expenditures. During the urbanization process, a careful and efficient examination of the urban spatial structure is crucial. Different from the traditional approach that relies on population or employment census data, this research exploits the nighttime light (NTL) intensity of the earth surface recorded by satellite sensors. The NTL intensity is represented as a continuous mathematical surface of human activities, and the elemental features of urban structures are identified by analogy with earth’s topography. We use a topographical metaphor of a mount to identify an urban center or subcenter and the surface slope to indicate an urban land-use intensity gradient. An urban center can be defined as a continuous area with higher concentration or density of employments and human activities. We successfully identified 33 urban centers, delimited their corresponding boundaries, and determined their spatial relations for Shanghai metropolitan area, by developing a localized contour tree method. In addition, several useful properties of the urban centers have been derived, such as 9% of Shanghai administrative area has become urban centers. We believe that this method is applicable to other metropolitan regions at different spatial scales.
Auteurs: Zuoqi Chen;Bailang Yu;Wei Song;Hongxing Liu;Qiusheng Wu;Kaifang Shi;Jianping Wu;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 11.-2017, volume: 55, issue:11, pages: 6305 - 6319
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Concept for a Flat Lens Design Using Dielectric Cylinders
Résumé:
A new design method called the array scattering method for a flat lens made of dielectric cylinders is presented. The method reconstructs the far-field radiation pattern of a 2-D arbitrary geometrical shape dielectric scatterer. Since the method has no restrictions on the near field, it allows us to alter the polarization currents distribution in order to obtain a better far-field performance for a periodic structure with a given unit cell size. The method also allows us to perform a simple parametric study on the limits of the unit cell size, taking into account the scatterer geometrical dimensions. This parameter (unit cell size) does not appear in the formulation if we use a method that assumes an infinite array of cylinders. The realization is done using the multiple scattering method, which is one of the most accurate methods to deal with arrays scattering. Nevertheless, the method is almost entirely analytic, not iterative and does not require multiple simulations in order to obtain the required objective.
Auteurs: Eran Falek;Reuven Shavit;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 5720 - 5731
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Dynamic Complex Baseband Pulse Compression Method for Chirp-Coded Excitation in Medical Ultrasound Imaging
Résumé:
Chirp-coded excitation can increase the signal-to-noise ratio (SNR) without degrading the axial resolution. Effective pulse compression (PC) is important to maintain the axial resolution and can be achieved with radio frequency (RF) and complex baseband (CBB) data (i.e., ${mathrm {PC}}_{mathrm {RF}}$ and ${mathrm {PC}}_{mathrm {CBB}}$ , respectively). ${mathrm {PC}}_{mathrm {CBB}}$ can further reduce the computational complexity compared to ${mathrm {PC}}_{mathrm {RF}}$ ; however, ${mathrm {PC}}_{mathrm {CBB}}$ suffers from a degraded SNR due to tissue attenuation. In this paper, we propose a new dynamic CBB PC method ( ${mathrm {PC}}_{mathrm {CBB-Dynamic}})$ that can improve the SNR while compensating for tissue attenuation. The compression filter coefficients in the ${mathrm {PC}}_{mathrm {CBB-Dynamic}}$ method are generated by dynamically changing the demodulation frequencies along with the depth. For PC, the obtained ${mathrm {PC}}_{mathrm {CBB-Dynamic}}$ coefficients are independently applied to the in-phase and quadrature components of the CBB data. To evaluate the performance of the proposed method, simulation, phantom, and in vivo studies were conducted, and all three studies showed improved SNR, i.e., maximally 3.87, 7.41, and 5.75 dB, respectively. In addition, the measured peak range sidelobe level of the proposed method yielded lower value- than the ${mathrm {PC}}_{mathrm {RF}}$ and ${mathrm {PC}}_{mathrm {CBB}}$ , and it also derived a suitable target location, i.e., a <0.07-mm target location error, while maintaining the axial resolution. In an in vivo abdominal experiment, the ${mathrm {PC}}_{mathrm {CBB-Dynamic}}$ method depicted brighter and clearer features in the hyperechoic region because highly correlated signals were produced by compensating for tissue attenuation. These results demonstrated that the proposed method can improve the SNR of chirp-coded excitation while preserving the axial resolution and the target location and reducing the computational complexity.
Auteurs: Jinbum Kang;Yeajin Kim;Wooyoul Lee;Yangmo Yoo;
Apparue dans: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Date publication: 11.-2017, volume: 64, issue:11, pages: 1698 - 1710
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Efficient Thickness Profile Design Method for Streamlined Airborne Radomes
Résumé:
The streamlined shapes of airborne radomes tend to cause severe degradation of the electromagnetic (EM) performance, which can be compensated by properly designing the radome thickness profile. Conventional variable thickness radomes based on optimization method yield excellent EM performance at the expense of 1) considerable design time consumed by the inevitable optimization process and 2) potential manufacturing difficulties as thickness profile tends to vary dramatically in the entire range of the radome. In this communication, we present an efficient thickness profile design method through introducing the concept of half-wave thickness under average incident angle. No optimization process is involved and gentle thickness profile variation is naturally guaranteed by the gradual variation of radome shape which determines the average incident angle. Both 2-D and 3-D cases are considered in computing the average incident angle. Results of a tangent-ogival airborne radome validate the effectiveness of the proposed method.
Auteurs: Wanye Xu;B. Y. Duan;Peng Li;Yuanying Qiu;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 6190 - 6195
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Electric Magnetic-Geared Machine for Electric Unmanned Aerial Vehicles
Résumé:
This paper proposes a new electric magnetic-geared (EMG) machine, which artfully incorporates the magnetic gear into an outer-rotor inserted permanent-magnet (PM) machine, purposely for electric unmanned aerial vehicle (e-UAV) application. The proposed EMG machine artfully shares the sandwiched-rotor for both the PM machine and the magnetic gear. As a result, the proposed machine can run in the high speed and high power for propelling the e-UAV. The design details, operation principles, static characteristics, and machine performances, as well as the propulsion performances of the proposed machine, are elaborated and discussed. The finite-element method is utilized to verify the validity of the machine design and performances, with emphasis on the e-UAV application.
Auteurs: Chunhua Liu;Jincheng Yu;Christopher H. T. Lee;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 6
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Family of Exponential-Based High-Order DGTD Methods for Modeling 3-D Transient Multiscale Electromagnetic Problems
Résumé:
A new family of exponential-based time integration methods are proposed for the time-domain Maxwell’s equations discretized by a high-order discontinuous Galerkin (DG) scheme formulated on locally refined unstructured meshes. These methods, which are developed from the Lawson method, remove the stiffness on the time explicit integration of the semidiscrete operator associated with the fine part of the mesh, and allow for the use of high-order time explicit scheme for the coarse part operator. They combine excellent stability properties with the ability to obtain very accurate solutions even for very large time step sizes. Here, the explicit time integration of the Lawson-transformed semidiscrete system relies on a low-storage Runge-Kutta (LSRK) scheme, leading to a combined Lawson-LSRK scheme. In addition, efficient techniques are presented to further improve the efficiency of this exponential-based time integration. For the efficient calculation of matrix exponential, we employ the Krylov subspace method. Numerical experiments are presented to assess the stability, verify the accuracy, and numerical convergence of the Lawson-LSRK scheme. They also demonstrate that the DG time-domain methods based on the proposed time integration scheme can be much faster than those based on classical fully explicit time stepping schemes, with the same accuracy and moderate memory usage increase on locally refined unstructured meshes, and are thus very promising for modeling 3-D multiscale electromagnetic problems.
Auteurs: Hao Wang;Li Xu;Bin Li;Stéphane Descombes;Stéphane Lantéri;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 5960 - 5974
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Hybrid Permanent Magnet Synchronous Motor With Two Different Rotor Sections
Résumé:
In this paper, a new hybrid permanent magnet (PM) synchronous motor with two-part rotor is proposed. The new motor is composed of surface mounted and interior magnet rotor segments on a stepped skewed shaft. The hybrid topology has wider constant power speed ratio than conventional surface mounted PM motors with relatively the same torque density. No-load and on-load finite-element analyses (FEA) are performed independently for both surface PM and interior PM synchronous motor. Superposition of the results is gathered to obtain the actual performance of the hybrid motor. The 2-D FEA results with skewed models are also performed at the final stage of the design. A prototype motor is manufactured and experimental results are obtained. Good agreement is observed between the simulations and test data for the proposed motor.
Auteurs: Oguzhan Ocak;Metin Aydin;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 5
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Interval Pattern Analysis Method of Array Antennas Based on Taylor Expansion
Résumé:
In this communication, a new Taylor expansion-based interval pattern analysis method is developed to predict the impact of the small excitation amplitude uncertainty on the radiated array pattern. The dependence problem of the classical interval arithmetic, which may lead to overestimation of performance intervals, is addressed in this communication. The proposed method approximates by approximating the antenna power values to the first order with respect to the uncertain amplitude. The new method is simpler and can produce more accurate bounds of the antenna pattern and the pattern features than the existing techniques. Several representative numerical examples are investigated to demonstrate the validity and efficiency of the proposed method.
Auteurs: Naigang Hu;Baoyan Duan;Wanye Xu;Jinzhu Zhou;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 6151 - 6156
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Ka-Band Doppler Radar in Robust and Precise Cardiopulmonary Remote Sensing
Résumé:
In this paper, a new Ka-band Doppler radar with an ability to remotely monitor respiration rate, heartbeat rate (HR), and heart rate variability (HRV) is presented. Exploiting the advantage of high sensitivity of Ka-band radar in sensing of chest-wall movement, we make more accurate reconstruction of cardiopulmonary activities from low-quality received signal. The advantage of using Ka-band radar is obtained by paying a penalty, which is harmonic interferences that make measuring of cardiopulmonary details infeasible in lots of real scenarios. In this paper, by using a more complete model of return signal, a new routine is introduced for the robust detection of breathing and HR that extremely alleviates the problems associated with harmonic interferences. Besides, a more suitable model is proposed, which can cover time-variability cardiorespiratory features. Taking advantage of this model and based on the unconditional orthonormal representation of band-limited signals, a filter with time-varying coefficients is proposed to extract HRV. This extraction is done without resorting to tracking HR trace that makes it more precise and robust than the conventional approach. The indicated filter enables us to suggest a novel approach to remove random body motion effects. By experimental data, the applicability of the new radar for a wide range of real world scenarios is investigated, and its advantages beside conventional approaches are proved practically in different aspects.
Auteurs: Seyed Mohammad Ali Tayaranian Hosseini;Hamidreza Amindavar;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 11.-2017, volume: 66, issue:11, pages: 3012 - 3022
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Method for Neural Spike Alignment: The Centroid Filter
Résumé:
Recordings made directly from the nervous system are a key tool in experimental electrophysiology and the development of bioelectronic medicines. Analysis of these recordings involves the identification of signals from individual neurons, a process known as spike sorting. A critical and limiting feature of spike sorting is the need to align individual spikes in time. However, electrophysiological recordings are made in extremely noisy environments that seriously limit the performance of the spike-alignment process. We present a new centroid-based method and demonstrate its effectiveness using deterministic models of nerve signals. We show that spike alignment in the presence of noise is possible with a 30 dB reduction in minimum SNR compared with the conventional methods. We present a mathematical analysis of the centroid method, characterizing its fundamental operation and performance. Furthermore, we show that the centroid method lends itself particularly well to hardware realization, and we present results from a low-power implementation that operates on an FPGA, consuming ten times less power than conventional techniques - an important property for implanted devices. Our centroid method enables the accurate alignment of spikes in sub-0 dB SNR recordings and has the potential to enable the analysis of spikes in a wider range of environments than has been previously possible. Our method thus has the potential to influence significantly the design of electrophysiological recording systems in the future.
Auteurs: Benjamin W. Metcalfe;Christopher T. Clarke;Nick Donaldson;John Taylor;
Apparue dans: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Date publication: 11.-2017, volume: 25, issue:11, pages: 1988 - 1997
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Methodology for Mining Frequent Itemsets on Temporal Data
Résumé:
Temporal data contain time-stamping information that affects the results of data mining. Traditional techniques for finding frequent itemsets assume that datasets are static and the induced rules are relevant across the entire dataset. However, this is not the case when data is temporal. In this paper, we are trying to improve the efficiency of mining frequent itemsets on temporal data. Since patterns can hold in either all or some of the intervals, we propose a new algorithm to restrict time intervals, which is called frequent itemset mining with time cubes. Our focus is developing an efficient algorithm for this mining problem by extending the well-known a priori algorithm. The notion of time cubes is proposed to handle time hierarchies. This is the way by which the patterns that happen periodically, during a time interval or both, are recognized. A new density threshold is also proposed to solve the overestimating problem of time periods and also make sure that discovered patterns are valid. We evaluate our algorithms via experiments.
Auteurs: Mazaher Ghorbani;Masoud Abessi;
Apparue dans: IEEE Transactions on Engineering Management
Date publication: 11.-2017, volume: 64, issue:4, pages: 566 - 573
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Mover Separated Linear Magnetic-Field Modulated Motor for Long Stroke Applications
Résumé:
Linear magnetic-field modulated (LMFM) motor exhibits high thrust force by effectively employing the magnetic-field modulation effect. In this paper, a new mover separated LMFM (MS-LMFM) motor is proposed, which successfully alleviates the space confliction between permanent magnets (PMs) and windings in the existing LMFM motor. The structure and the operation principle of the existing and proposed motor are described, and the major design parameters are optimized for maximum thrust force. Moreover, electromagnetic performances of both motors are compared by finite-element method. Theoretical and simulation analysis shows that the proposed motor can exhibit enhanced force performance than the existing one under fixed copper loss. Simultaneously, reduced iron and PM losses can also be obtained by proposed motor. Finally, a 3-D modeling MS-LMFM motor is built for a global observation of motor structure and further verification of the 2-D analysis.
Auteurs: Wenxiang Zhao;Shiyuan Wang;Jinghua Ji;Liang Xu;Zhijian Ling;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 5
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Nine-Phase Permanent Magnet Synchronous Motor With Consequent Pole Rotor for High-Power Traction Applications
Résumé:
Although three-phase permanent magnet (PM) motors are quite common in industry, multi-phase PM motors are used in special applications where high power and redundancy are required. Multi-phase PM motors offer higher torque/power density than conventional three-phase PM motors. In this paper, a novel multi-phase consequent pole PM (CPPM) synchronous motor is proposed. The constant power–speed range of the proposed motor is quite wide as opposed to conventional PM motors. The design and the detailed finite-element analysis of the proposed nine-phase CPPM motor and performance comparison with a nine-phase surface mounted PM motor are completed to illustrate the benefits of the proposed motor.
Auteurs: M. Onsal;Y. Demir;M. Aydin;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 6
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Optimization Model for Reliable Team Formation Problem Considering Experts’ Collaboration Network
Résumé:
The objective of this study is to propose a new optimization model for the formation of a reliable team of experts, who have a certain number of skills and best collaboration with each other. The proposed mathematical model maximized team reliability by considering the probability of unreliable experts that may leave the team with the probability (1-Q) and proposed a backup for each unreliable member. In this paper, a new model was developed for simultaneously forming a team with three key factors: 1) expert's skills; 2) expert's collaboration network; and 3) expert's reliability. This model was evaluated by two numerical studies on both artificial and real-life datasets with small and big data. The optimum combination of team members with regard to skills, collaboration network, and reliability will help managers in performing their projects or operations. Therefore, the new optimization model, called the reliable team formation problem, proposed team members in two sets consisting of main and backup members.
Auteurs: Mohammad Fathian;Mohamad Saei-Shahi;Ahmad Makui;
Apparue dans: IEEE Transactions on Engineering Management
Date publication: 11.-2017, volume: 64, issue:4, pages: 586 - 593
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Sensitive Excitation Technique in Nondestructive Inspection for Underground Pipelines by Using Differential Coils
Résumé:
In general, a magnetic flux leakage (MFL) pipeline inspection gauge (PIG) has been applied to nondestructive testing for investigating ferromagnetic materials, such as underground gas pipelines. Although MFL PIG is efficient to the inter-city large-scale pipelines, it is hard to apply to small-size pipelines that are usually installed in the city, because the permanent magnet for MFL PIG is too big and heavy to operate inside the small pipe. The strong adhesive magnetic force of permanent magnet to the pipe wall also prevents the usage of MFL PIG in small pipelines. In this paper, we propose a new technology of nondestructive inspection by using a differential coil, which is easy to be manufactured with lightweight, low cost, and simple structure for operating inside the underground pipelines. Comparing with the conventional permanent-magnet MFL PIG, the results of the proposed system could also maximize the detection sensitivity of defect signals and minimize the magnetic adhesive force on the pipe wall simultaneously.
Auteurs: Hui Min Kim;Gwan Soo Park;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 4
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A New Unsupervised Hyperspectral Band Selection Method Based on Multiobjective Optimization
Résumé:
Unsupervised band selection methods usually assume specific optimization objectives, which may include band or spatial relationship. However, since one objective could only represent parts of hyperspectral characteristics, it is difficult to determine which objective is the most appropriate. In this letter, we propose a new multiobjective optimization-based band selection method, which is able to simultaneously optimize several objectives. The hyperspectral band selection is transformed into a combinational optimization problem, where each band is represented by a binary code. More importantly, to overcome the problem of unique solution selection in traditional multiobjective methods, we develop a new incorporated rank-based solution set concentration approach in the process of Tchebycheff decomposition. The performance of our method is evaluated under the application of hyperspectral imagery classification. Three recently proposed band selection methods are compared.
Auteurs: Xia Xu;Zhenwei Shi;Bin Pan;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 11.-2017, volume: 14, issue:11, pages: 2112 - 2116
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Noise-Efficient 36 nV/ $surd $ Hz Chopper Amplifier Using an Inverter-Based 0.2-V Supply Input Stage
Résumé:
This paper presents an analog front end (AFE) that achieves a high noise efficiency by using a chopper amplifier with a 0.2-V supply inverter-based input stage followed by a 0.8-V supply stage. The high input-stage current needed to reduce the input-referred noise is drawn from the 0.2-V supply, significantly reducing power consumption. The 0.8 V stage provides high gain and signal swing, improving linearity. Biasing and common-mode rejection techniques for the ultra-low-voltage stage are presented. The AFE is implemented in a 0.18 $mu text{m}$ CMOS process and integrates the chopper low-noise instrumentation amplifier, a programmable-gain amplifier, and an antialiasing filter. The AFE consumes 0.79 $mu text{W}$ and achieves a competitive power efficiency factor (PEF) of 1.6 and an input noise of 0.94 $mu text{V}_{text {rms}}$ integrated from 0.5 to 670 Hz while maintaining a 36 nV/ $surd $ Hz input noise density down to 0.5 Hz. The included 0.8/0.2-V buck converter may be used to provide the 0.2-V supply at 72%–74% efficiency without significantly increasing noise, yielding a PEF of 1.8.
Auteurs: Frank M. Yaul;Anantha P. Chandrakasan;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 11.-2017, volume: 52, issue:11, pages: 3032 - 3042
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Nonlinear State Estimator-Based Decentralized Secondary Voltage Control Scheme for Autonomous Microgrids
Résumé:
This study proposes a fully decentralized secondary voltage control scheme which employs the state estimation method in autonomous microgrids. Based on a large-signal dynamic model of a microgrid, a linear parameter varying based state estimator that is localized in each distributed generation (DG) unit serves as an alternative communication role and obtains the dynamics of the other DG units independently. A linear matrix inequality formulation for pole placement condition is derived for the state estimator design. A decentralized secondary voltage controller is, thus, able to achieve accurate reactive power sharing and average voltage restoration without any additional communication links. Our approach offers superior reliability, flexibility, and economic efficiency because of the irrelevance of communications to its performance, which is essential when conventional centralized or distributed methods are likely to yield towards poor performance or even instability under communication latency or data drop-out conditions. Simulation results that verify the effectiveness of the proposed methodology are provided.
Auteurs: Wei Gu;Guannan Lou;Wen Tan;Xiaodong Yuan;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 11.-2017, volume: 32, issue:6, pages: 4794 - 4804
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Nonparametric Statistical Technique for Modeling Overland TMI (2A12) Rainfall Retrieval Error
Résumé:
In this letter, we evaluate a nonparametric error model for Tropical Rainfall Measurement Mission (TRMM) passive microwave (PMW) rainfall (2A12) product over coverage in the southern continental United States, and assess the impact of surface soil moisture information on the model’s performance. Reference precipitation was based on high-resolution (5 min/1 km) rainfall fields derived from the NOAA/National Severe Storms Laboratory multiradar multisensor system. The error model was evaluated using a K-fold validation experiment using systematic and random error statistics of the model-adjusted TRMM Microwave Imager rainfall point estimates, and ensemble verification statistics of the corresponding prediction intervals. Results show better performance, particularly in the accuracy of the prediction intervals, when near-surface soil moisture was used as input parameter. The error model can be extended using the TRMM and Global Precipitation Measurement satellite missions’ precipitation radar rainfall and satellite soil moisture data sets to characterize globally the uncertainty of PMW products.
Auteurs: M. A. E. Bhuiyan;E. N. Anagnostou;P.-E. Kirstetter;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 11.-2017, volume: 14, issue:11, pages: 1898 - 1902
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Note on Parallel Asynchronous Channels With Arbitrary Skews
Résumé:
A zero-error coding scheme of asymptotic rate ${log _{2} (1+sqrt {5}) - 1} $ was recently described for a communication channel composed of parallel asynchronous lines satisfying the so-called no switch assumption. We prove that this is in fact the highest rate attainable, i.e., the zero-error capacity of this channel.
Auteurs: Mladen Kovačević;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 11.-2017, volume: 63, issue:11, pages: 7320 - 7321
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Novel 3-D Concentric-Winding-Type Three-Phase Variable Inductor for Reactive Power Compensation in Electric Power Systems
Résumé:
A variable inductor consists of a magnetic core, primary dc windings, and secondary ac windings. The effective inductance of the secondary ac winding can be controlled by the primary dc current because of its nonlinear magnetic characteristic. Hence, variable inductors can be applied as a reactive power compensator for voltage stabilization in electric power systems, and have desirable features such as a simple and robust structure, low cost, and high reliability. In a previous paper, a concentric-winding-type three-phase variable inductor with a 2-D structure has been proposed. It was demonstrated that the 2-D variable inductor has good controllability and a low distortion current. To further increase productivity and reduce costs, this paper presents a novel concentric-winding-type three-phase variable inductor with a 3-D structure. It is demonstrated that the leakage flux of the proposed 3-D variable inductor is reduced by more than 30%. Furthermore, a 6.6 kV–100 kVA 3-D variable inductor is designed and compared to its 2-D counterpart. It is proved that eddy current loss, which is induced within an oil-immersed self-cooled tank because of leakage flux from the variable inductor, can be reduced to one-third of that of the 2-D variable inductor.
Auteurs: Kenji Nakamura;Yuta Yamada;Ryusei Nono;Takashi Ohinata;Kenji Arimatsu;Osamu Ichinokura;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 4
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Novel Approach for 2-D Electromagnetic Field Analysis of Surface Mounted Permanent Magnet Synchronous Motor Taking Into Account Axial End Leakage Flux
Résumé:
This paper proposes a novel approach for electromagnetic field analysis of surface-mounted permanent synchronous machines taking into account axial end leakage flux. In order to calculate the axial end leakage flux using the 2-D finite-element analysis (FEA), the leakage magnetic flux in the axial direction is reflected to the 2-D model by applying the permeability factor into the slot area. The permeability factor is derived by the equivalent magnetic circuit method. At this time, the permeability factor is calculated by considering the main leakage path in the slot and the leakage path in the axial direction of air region. The effectiveness of the proposed method is verified by comparing the results of the proposed method with the experimental results as well as the conventional 2-D FEA results and the 3-D FEA results.
Auteurs: Jae-Woo Jung;Hyung-Il Park;Jung-Pyo Hong;Byeong-Hwa Lee;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 4
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Novel Approach for Plastic-Bonded Magnets of the Type MQU-F Melt Spun NdFeGaB-Type Alloys
Résumé:
Permanent magnets have attracted research interest in the last decades as they are used in a wide range of applications, in consumer electronics, motors, electric generators, and nano-micro scale applications [microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS)]. Plastic-bonded magnets (PBMs)—composites with permanent magnetic powder embedded in a polymer binder—are considered among the most innovative methods of manufacturing magnets at lower temperatures than conventional methods. In this framework, plastic-bonded NdFeGaB magnets were prepared through a novel “high-density PBM” approach and their structural and magnetic properties are presented in this paper. High densities of the order 82% of the theoretical estimated density value were achieved opening a new path toward permanent magnets applications.
Auteurs: S. Karamanou;M. Gjoka;E. Devlin;V. Psycharis;A. Ioannidou;G. Giannopoulos;D. Niarchos;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 3
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Novel Approach for QoS-Aware Joint User Association, Resource Block and Discrete Power Allocation in HetNets
Résumé:
We consider joint optimization of user-to-base-station (BS) association, and time-frequency resource block (RB) and power allocation in heterogeneous networks (HetNets). The objective is to develop a design: 1) that maximizes the number of users accommodated in the network while satisfying their quality of service demands and 2) that minimizes usage of the resources required to meet these demands. We investigate two novel instances of HetNets with opportunistic RB-reuse. In the first instance, user-to-BS associations and power allocations can be time-shared, and the RBs can be reused during the signaling interval. For this instance, it is shown that the design problem can be approximated by a problem that yields tight convex upper and lower bounds on the objective. In contrast, the second instance represents a case in which the RBs can be reused, but the user-to-BS associations and power allocations are not time-shared, and hence, fixed throughout the signaling interval. The latter case gives rise to a combinatorial optimization problem, which we provide an approximate solution for by using a polynomial-complexity two-phase approach based on semidefinite relaxation with randomization.
Auteurs: Hamza Umit Sokun;Ramy H. Gohary;Halim Yanikomeroglu;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 11.-2017, volume: 16, issue:11, pages: 7603 - 7618
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Novel Asymmetric and Unconventional Stator Winding Configuration and Placement for a Dual Three-Phase Surface PM Motor
Résumé:
Multi-phase permanent magnet (PM) motors are becoming more popular because of their higher torque densities, enhanced efficiency, and fault-tolerant capabilities. In this paper, a novel six-phase PM synchronous motor with a new asymmetric stator ac winding scheme and placement is proposed. Two identical dual three-phase asymmetrical winding sets are placed in two separate half of the stator in 180 mechanical degrees. This approach reduces the phase resistance and thus copper losses. Torque quality of the proposed motor is also analyzed using 2-D finite element method in detail. It can be concluded that the proposed novel asymmetric stator has more advantages to offer than conventional six-phase PM motors.
Auteurs: Y. Demir;M. Aydin;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 5
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Novel Boresight and Conical Pattern Reconfigurable Antenna With the Diversity of 360° Polarization Scanning
Résumé:
A novel design of boresight and conical pattern reconfigurable antenna with the capability of 360° polarization scanning is presented in this paper. At boresight mode, the antenna produces a continuously reconfigurable polarization over 360° in the azimuth plane, which provides adaptive-polarization reception between a transmitter and a receiver. The antenna is analyzed in terms of the electric field with an explanation of the generation of TM11 and TM02 resonant modes, which provides an innovative method of designing pattern reconfigurable antennas for the WLAN applications. The proposed method is validated by a good agreement between simulation and experimental results for an antenna designed to provide boresight and conical pattern switching at 2.4 GHz. The gain of 6.05 dBi and efficiency of 86.7% are measured in the boresight mode, corresponding to 4.39 dBi and 82.4% at conical mode.
Auteurs: Yang Yang;Roy B. V. B. Simorangkir;Xi Zhu;Karu Esselle;Quan Xue;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 11.-2017, volume: 65, issue:11, pages: 5747 - 5756
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Novel Conflict-Free Parallel Memory Access Scheme for FFT Processors
Résumé:
This brief presents a novel conflict-free access scheme for memory-based fast Fourier transform (FFT) processors. It is proved to satisfy the constraints of the mixed-radix, continuous-flow, parallel-processing, and variable-size FFT computations. An address generation unit is also designed and outperforms existing architectures with reduced gate delay and lower hardware complexity.
Auteurs: Qian-Jian Xing;Zhen-Guo Ma;Ying-Ke Xu;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 11.-2017, volume: 64, issue:11, pages: 1347 - 1351
Editeur: IEEE
Document complet vers site de l'éditeur
 
» A Novel Consequent-Pole Hybrid Excited Vernier Machine
Résumé:
This paper proposes a novel consequent-pole hybrid excited vernier machine (CPHEVM) by combining hybrid excited concept and vernier structure, and the consequent-pole magnet arrangement is employed on outer rotor. The proposed machine can achieve high torque density at low speed and excellent flux-weakening capability at high speed, which are highly desirable for electric vehicle applications. The direct current field windings are embedded between modulating poles, which increase the space utilization ratio to enable flux regulation without decreasing torque capability. The configuration, operation principle, and design consideration of the proposed CPHEVM are described, respectively. Finite-element method is employed to analyze the electromagnetic performance of the selected CPHEVMs with various slot/pole combinations, including flux regulation capability, back-electromagnetic force, and torque characteristics with and without flux-weakening control.
Auteurs: Haitao Wang;Shuhua Fang;Hui Yang;Heyun Lin;Dong Wang;Yibo Li;Chenxiao Jiu;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 11.-2017, volume: 53, issue:11, pages: 1 - 4
Editeur: IEEE
Document complet vers site de l'éditeur
 


Publication archives by date
    2017:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2016:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2015:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2014:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2013:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2012:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2011:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2010:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre    
    2009:   janvier     février     mars     avril     mai     juin     juillet     août     septembre     octobre     novembre     décembre