###### Accueil » Publications dans le domaines des technologies » 09-2017
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 Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 09-2017 trié par par titre, page: 0
» $L/S$ -Band Frequency Reconfigurable Multiscale Phased Array Antenna With Wide Angle Scanning
 Résumé:A frequency reconfigurable phased array element is presented. The operational band of the single port L/S-band antenna can be selected by modifying the element apertures with p-i-n diode switches. The antenna element satisfies strict requirements on its frequency band separation (2.2:1), size, feeding structure, and control lines to be integrated into a phased array system. A multiscale array topology is proposed to achieve wide angle scanning (±60°) in both operational bands of the array. Auteurs: Nadia Haider;Alexander G. Yarovoy;Antoine G. Roederer; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4519 - 4528 Editeur: IEEE Document complet vers site de l'éditeur
» ${W}$ -Band Direct-Modulation >20-Gb/s Transmit and Receive Building Blocks in 32-nm SOI CMOS
 Résumé:This paper presents Gb/s-speed circuit building blocks in 32-nm CMOS SOI, for a > 20-Gb/s Cartesian direct-modulation $W$ -band transmitter. Transmitter systems non-idealities and performance limitations are discussed, and circuit design techniques and analyses are presented. The transmitter employs two 2-b high-speed RF digital-to-analog converters driven in quadrature, 20-dB gain $W$ -band LO drivers, and 30-Gb/s high-speed digital retimers and deserializers, and is capable of supporting BPSK/PAM4/QPSK/16-QAM modulation schemes, at a saturated output power $P_{\mathrm{ sat}}$ of +4 dBm. A maximum data rate of 20 Gb/s was achieved when operating in QPSK mode, 4 Gb/s in 16-QAM mode, and 12 Gb/s in both BPSK and PAM4 modes. The chip occupies 1.40.8 mm2 and consumes 110 mW in BPSK/PAM4 modes and 220 mW in QPSK and 16-QAM modes, resulting in the state-of-the-art 9-, 11-, and 55-pJ/b peak efficiencies, respectively. A mixer-first wideband $W$ -band receiver that includes a passive mixer and a wideband transimpedance amplifier is also presented. Measurements of the receiver chip demonstrated its capability to downconvert and amplify highly complex modulated waveforms (> 256-QAM), and at high data rates, up to 60 Gb/s in 64-QAM, which proves the feasibility of building high dynamic-range mm-wave receivers with bandwidth greater than 30 GHz. The receiver chip was also built in 32-nm CMOS SOI, occupying a core area of 0.180.1 mm2 Auteurs: Hasan Al-Rubaye;Gabriel M. Rebeiz; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2277 - 2291 Editeur: IEEE Document complet vers site de l'éditeur
» ${W}$ -Band Time-Domain Multiplexing FMCW MIMO Radar for Far-Field 3-D Imaging
 Résumé:In this paper, a radar demonstrator system with real-time capability operating at ${W}$ -band is presented. It operates at 90–100 GHz and provides 3-D information about the illuminated scene. The system uses frequency modulated continuous wave signals to extract range information whereupon long-range applications are aimed at. It consists of a sparse array of 22 transmitting and 22 receiving antennas and makes use of the multiple input multiple output (MIMO) principle. A back-propagation algorithm provides cross-range information. With the help of simulations and a simulated annealing algorithm, the geometry of the sparse array is optimized to meet application requirements using the available hardware. In this paper, the demonstrator system is described and the imaging theory is shortly reviewed. Measurements are presented to verify simulation results as well as 3-D imaging and long-range capability. Auteurs: Daniela Bleh;Markus Rösch;Michael Kuri;Alexander Dyck;Axel Tessmann;Arnulf Leuther;Sandrine Wagner;B. Weismann-Thaden;H.-P. Stulz;Martin Zink;M. Rießle;R. Sommer;J. Wilcke;M. Schlechtweg;B. Yang;Oliver Ambacher; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3474 - 3484 Editeur: IEEE Document complet vers site de l'éditeur
» 0.5–20-GHz UWB Distributed Combiners and Dividers for Multi-Antenna Transceivers
 Résumé:This paper presents discrete active combiners and dividers for ultra-wideband (UWB) applications. The proposed solution exploits distributed amplifier techniques to perform the combination and division of signals over the band from 0.5 to 20 GHz. Three circuit boards are demonstrated: a 2-to-1 active combiner with 17-dB gain, a 4-to-1 active combiner with 30-dB gain, and a 2-to-1 active divider with 10-dB gain. Standard S-parameter and large-signal measurements have been performed to characterize the presented circuit. Multi-antenna demonstrators have been setup to validate the device functionality in more complex scenarios. In particular combination of wideband and narrowband communications has been demonstrated, as well as the use of the combiners for UWB antenna arrays. The presented 4-to-1 combiner shows the best values in terms of gain and a number of inputs with respect to the state-of-art (SOA), while the performance of the other presented devices is comparable to the SOA despite using SMA connectors in place of on-chip measurements. Auteurs: Paolo Valerio Testa;Corrado Carta;Marvin Barahona;Frank Ellinger; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3087 - 3098 Editeur: IEEE Document complet vers site de l'éditeur
» 1-D Fast Neutron Source Localization Using Digital Pixelated 3-D Position-Sensitive CdZnTe Detectors
 Résumé:Recoil of constituent nuclei from neutron elastic scatter in pixelated, 3-D CdZnTe gamma-ray detectors is detectable given current low energy thresholds. Fast neutrons are attenuated by CdZnTe detectors via outscatter and measured gradients in neutron interaction rates across detector pixels that enables 1-D fast neutron source localization through a maximum likelihood estimator. Experimental results using an MP320 deuterium–deuterium neutron generator with the four detector crystal Orion prototype successfully localize four different source locations across a 1-D field of view to within absolute measurement errors between 2.5° and 14.0°. Auteurs: David Goodman;Michael Streicher;Yuefeng Zhu;Steven Brown;Zhong He; Apparue dans: IEEE Transactions on Nuclear Science Date publication: 09.-2017, volume: 64, issue:9, pages: 2531 - 2535 Editeur: IEEE Document complet vers site de l'éditeur
» 11th?IEEE UAE Student Day Hosted by Al Ain University [Around the Globe]
 Résumé:Presents information on the 11th IEEE UAE Student Day. Auteurs: Nazih Khaddaj Mallat; Apparue dans: IEEE Microwave Magazine Date publication: 09.-2017, volume: 18, issue:6, pages: 137 - 138 Editeur: IEEE Document complet vers site de l'éditeur
» 16th Mediterranean Microwave Symposium Hosted by Al Ain University [Conference Report]
 Résumé:Presents information on the 16th Mediterranean Microwave Symposium. Auteurs: Nazih Khaddaj Mallat; Apparue dans: IEEE Microwave Magazine Date publication: 09.-2017, volume: 18, issue:6, pages: 132 - 134 Editeur: IEEE Document complet vers site de l'éditeur
» 2-D High-Order DGTD Method and Its Application in Analysis of Sheath Propagation Characteristics
 Résumé:A 2-D discontinuous Galerkin time-domain (DGTD) scheme based on high-order hierarchical basis function is presented in this paper. Combined with the shift operator method solving the electromagnetic problem of dispersive media in finite-difference time domain, the iterative formula of DGTD method in dealing with plasma media is given. On this basis, taking the example of line element radiation, the computing ability of different basis functions is compared. To study the transmission characteristics of the electromagnetic (EM) wave in sheath, the DGTD calculation models of the plasma sheath of a blunt cone at different flight heights and velocities are established using Lagrange interpolation technique based on the calculation results of COMSOL (business software). The influences of antenna position, flight altitude, and flight speed on transmission characteristics of the EM wave are discussed through calculation and analyses. Auteurs: Linqian Li;Bing Wei;Qian Yang;Xin Yang;Debiao Ge; Apparue dans: IEEE Transactions on Plasma Science Date publication: 09.-2017, volume: 45, issue:9, pages: 2422 - 2430 Editeur: IEEE Document complet vers site de l'éditeur
» 2017 IEEE\/IFR Award for IERA [Industrial Activities]
 Résumé: Auteurs: Erwin Prassler;Arturo Baroncelli; Apparue dans: IEEE Robotics & Automation Magazine Date publication: 09.-2017, volume: 24, issue:3, pages: 8 - 11 Editeur: IEEE Document complet vers site de l'éditeur
» 45–110 GHz Quad-Ridge Horn With Stable Gain and Symmetric Beam
 Résumé:A quad-ridge horn antenna with stabilized gain and minimum difference between E- and H-plane half-power beamwidths (HPBWs) is demonstrated for operation over 45–110 GHz bandwidth. Multistep flaring and corrugations on a finite ground plane are applied to obtain stable radiation patterns with 16-dBi minimum gain over the entire range. The computational studies are validated through measurements of a 3-D printed prototype using the direct metal laser sintering (DMLS) process. Accurate fabrication with achieved surface roughness of $< 1.7~\mu \text{m}$ of the fabricated antenna is verified with digital microscope. The obtained gain variation, VSWR, and HPBW variation with rotation and over 45–110 GHz bandwidth are below 1.7 dB, 1.7:1, and 9°, respectively. This work demonstrates that the DMLS is a viable fabrication process for wideband horn antennas at millimeter-wave frequencies. Auteurs: Sara Manafi;Muhannad Al-Tarifi;Dejan S. Filipovic; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4858 - 4863 Editeur: IEEE Document complet vers site de l'éditeur
» 64 × 0.5 Gbaud Nonlinear Frequency Division Multiplexed Transmissions With High Order Modulation Formats
 Résumé:Nonlinear frequency division multiplexing (NFDM) with the modulation of the nonlinear Fourier spectrum (both discrete and continuous parts) has been recently considered as a promising transmission method to combat fiber nonlinearity impairments. In this paper, we experimentally demonstrate the generation, detection, and transmission performance of NFDM systems where the transmitted information is encoded directly onto the continuous part of the nonlinear spectrum using 64 overlapped 0.5 Gbaud channels with high order QAM formats (e.g., 16 QAM, 32 QAM, and 64 QAM). In comparison with the conventional orthogonal frequency division multiplexing transmission, which is the linear counterpart of NFDM transmission, clear performance advantage of NFDM systems, up to 1.3 dB, has been observed. This result indicates for the first time the performance benefit of NFDM transmission over its linear counterpart, showing the high potential of this emerging technology. Auteurs: Son Thai Le;Henning Buelow; Apparue dans: Journal of Lightwave Technology Date publication: 09.-2017, volume: 35, issue:17, pages: 3692 - 3698 Editeur: IEEE Document complet vers site de l'éditeur
» In Vivo High-Efficiency Wireless Power Transfer With Multisine Excitation
 Résumé:This paper presents a systematic design of a high-efficiency magnetic resonant wireless power transfer (MR-WPT) system for biomedical implants based on the unconventional multisine (MS) transmission waveform. The MS waveform featuring a high peak to average power ratio can boost the system efficiency with an elaborate design. Optimizations on flexible coil, system model, and rectifier design are all considered to strengthen its efficiency improvement as well as eliminate its drawbacks. With all the proposed optimizations implemented, the MS waveform has been applied for the first time in practical MR-WPT system for in vivo power delivery. A 6.78-MHz MR-WPT system with 18-mm implant depth is realized for wirelessly powering a spinal cord stimulator. It achieves an overall system efficiency (both coils and rectifier included) of 50.7% with a three-tone 230-kHz tone spacing MS waveform postimplantation in the rodent model. Low specific absorption rate and the tissue temperature rising from electromagnetic fields in the body are also verified to guarantee a safe and practical wireless power link for biomedical implants. Auteurs: Zhongtao Liu;Zheng Zhong;Yong-Xin Guo; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3530 - 3540 Editeur: IEEE Document complet vers site de l'éditeur
» In Vivo Intracardiac Vector Flow Imaging Using Phased Array Transducers for Pediatric Cardiology
 Résumé:Two-dimensional blood speckle tracking (ST) has shown promise for measuring complex flow patterns in neonatal hearts using linear arrays and high-frame-rate plane wave imaging. For general pediatric applications, however, the need for phased array probes emerges due to the limited intercostal acoustic window available. In this paper, a clinically approved real-time duplex imaging setup with phased array probes was used to investigate the potential of blood ST for the 2-D vector flow imaging of children with congenital heart disease. To investigate transmit beam pattern and tracking accuracy, straight tubes with parabolic flow were simulated at three depths (4.5, 7, and 9.5 cm). Due to the small aperture available, diffraction effects could be observed when approaching 10 cm, which limited the number of parallel receive beams that could be utilized. Moving to (slightly) diverging beams was shown to solve this issue at the expense of a loss in signal-to-noise ratio. To achieve consistent estimates, a forward–backward tracking scheme was introduced to avoid measurement bias occurring due to tracking kernel averaging artifacts at flow domain boundaries. Promising results were observed for depths <10 cm in two pediatric patients, where complex cardiac flow patterns could be estimated and visualized. As a loss in penetration compared with color flow imaging is expected, a larger clinical study is needed to establish the clinical feasibility of this approach. Auteurs: Solveig Fadnes;Morten Smedsrud Wigen;Siri Ann Nyrnes;Lasse Lovstakken; Apparue dans: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control Date publication: 09.-2017, volume: 64, issue:9, pages: 1318 - 1326 Editeur: IEEE Document complet vers site de l'éditeur
» A $2 Million Contest Seeks Solutions [Spectral Lines]  Résumé:In the season finale of HBO's television series "Silicon Valley," fictional startup company Pied Piper's attempt to create a decentralized Internet appears to have failed spectacularly, thanks to mobilephone explosions and a disastrous attempt to move a server. But then the distraught founders discover that their network is actually ticking along just fine. How? It turns out that the network has jumped to smart refrigerators. Now that's resilient! The Internet of Refrigerators is, of course, fiction. But could an Internet that is this resilient-or nearly so-become a reality? Mozilla and the U.S. National Science Foundation think it's possible, and they aim to accelerate its creation by offering US$2 million in prize money to the teams that invent it—or at least get close. Auteurs: Tekla S. Perry; Apparue dans: IEEE Spectrum Date publication: 09.-2017, volume: 54, issue:9, pages: 8 - 8 Editeur: IEEE Document complet vers site de l'éditeur
» A $K$ -Band Portable FMCW Radar With Beamforming Array for Short-Range Localization and Vital-Doppler Targets Discrimination
 Résumé:This paper presents a printed circuit board realization of a $K$ -band portable frequency-modulated continuous-wave radar transceiver with beamforming array for short-range localization. The transmitter channel of the proposed radar consists of a free-running voltage-controlled oscillator (VCO) and a single patch antenna. A linear frequency-modulated chirp signal is generated by the VCO, which is controlled by an analog “sawtooth” voltage generator. The receiver channel has a four-element linear beamforming array, a six-port circuit, and a baseband circuit. The beam of the array can be continuously steered in a range of ±45° on the $H$ -plane through an array of vector controllers. Each vector controller is capable of simultaneously controlling the phase and the amplitude of the corresponding array element. The design principle of the binary-phase-shift attenuator, the vector controller, and the radar system are discussed. Calibration method of the array is introduced to minimize the errors caused by component variation and fabrication. The radiation patterns of the array with phase-only beam steering and phase-amplitude beamforming are measured and compared, demonstrating the advantage of the beamforming design. System-level experiments showed that the proposed solution is suitable for short-range localization. In addition, experiments with a human subject revealed the capability of the proposed radar system to discriminate a human target from other objects based on the vital-Doppler effect. Auteurs: Zhengyu Peng;Lixin Ran;Changzhi Li; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3443 - 3452 Editeur: IEEE Document complet vers site de l'éditeur
» A ${Z}$ -Transform Method for Synthesis of Unequal-Length Multisection Transmission Lines for Multiband Applications
 Résumé:A method based on the $Z$ -transform is demonstrated to cascade transmission line sections of unequal lengths and achieve multiband and/or wideband properties. Unlike previous methods based on the $Z$ -transform, the proposed method associates the $z^{-1}$ term with the infinitesimal length of the unit segment. Consequently, any electrical length can be expressed in the $z^{-1}$ form. Therefore, while the previous methods are restricted to cascading lines of a commensurate length only, the proposed method can be applied to those of incommensurate lengths. Furthermore, the $z$ -polynomials for triple or more bands can be constructed by multiplying a combination of single- and dual-band polynomials, which remarkably simplifies the entire procedure to develop multiband and/or wideband circuits with virtually no limitation in terms of the number and/or combination of frequencies. The validity and practicality of the proposed method is verified with experimental results for various impedance transformers for real loads and Wilkinson power dividers; the results show the independence in the number and combination of operating frequencies as well as a dual-band operation with a center frequency ratio as large as 7.75. Auteurs: Joonsuk Kim;Yongshik Lee; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3200 - 3210 Editeur: IEEE Document complet vers site de l'éditeur
» A 0.3-V 1- $\mu \text{W}$ Super-Regenerative Ultrasound Wake-Up Receiver With Power Scalability
 Résumé:This brief presents an ultralow-power wake-up receiver using ultrasound for Internet of Things applications. To achieve both high sensitivity and low power consumption, we propose a Colpitts-oscillator-based super-regenerative receiver (COSR). Owing to the simple architecture of the proposed COSR, a lowest supply voltage operation of 0.3 V and a smallest area are achieved. Furthermore, the power consumption of the proposed wake-up receiver is scalable and is determined by the input signal sensitivity and data rate, which are configurable by the user. In a field test, the proposed wake-up receiver consumes $1~\mu \text{W}$ , which is smaller by 77% than that of a conventional ultrasound wake-up receiver at a comparable communication distance and data rate. Auteurs: Hiroshi Fuketa;Shinichi O’uchi;Takashi Matsukawa; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1027 - 1031 Editeur: IEEE Document complet vers site de l'éditeur
» A 0.3-V 1- $\mu \text{W}$ Super-Regenerative Ultrasound Wake-Up Receiver With Power Scalability
 Résumé:This brief presents an ultralow-power wake-up receiver using ultrasound for Internet of Things applications. To achieve both high sensitivity and low power consumption, we propose a Colpitts-oscillator-based super-regenerative receiver (COSR). Owing to the simple architecture of the proposed COSR, a lowest supply voltage operation of 0.3 V and a smallest area are achieved. Furthermore, the power consumption of the proposed wake-up receiver is scalable and is determined by the input signal sensitivity and data rate, which are configurable by the user. In a field test, the proposed wake-up receiver consumes $1~\mu \text{W}$ , which is smaller by 77% than that of a conventional ultrasound wake-up receiver at a comparable communication distance and data rate. Auteurs: Hiroshi Fuketa;Shinichi O’uchi;Takashi Matsukawa; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1027 - 1031 Editeur: IEEE Document complet vers site de l'éditeur
» A 0.3-V 1- $\mu \text{W}$ Super-Regenerative Ultrasound Wake-Up Receiver With Power Scalability
 Résumé:This brief presents an ultralow-power wake-up receiver using ultrasound for Internet of Things applications. To achieve both high sensitivity and low power consumption, we propose a Colpitts-oscillator-based super-regenerative receiver (COSR). Owing to the simple architecture of the proposed COSR, a lowest supply voltage operation of 0.3 V and a smallest area are achieved. Furthermore, the power consumption of the proposed wake-up receiver is scalable and is determined by the input signal sensitivity and data rate, which are configurable by the user. In a field test, the proposed wake-up receiver consumes $1~\mu \text{W}$ , which is smaller by 77% than that of a conventional ultrasound wake-up receiver at a comparable communication distance and data rate. Auteurs: Hiroshi Fuketa;Shinichi O’uchi;Takashi Matsukawa; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1027 - 1031 Editeur: IEEE Document complet vers site de l'éditeur
» A 0.3-V 1- $\mu \text{W}$ Super-Regenerative Ultrasound Wake-Up Receiver With Power Scalability
 Résumé:This brief presents an ultralow-power wake-up receiver using ultrasound for Internet of Things applications. To achieve both high sensitivity and low power consumption, we propose a Colpitts-oscillator-based super-regenerative receiver (COSR). Owing to the simple architecture of the proposed COSR, a lowest supply voltage operation of 0.3 V and a smallest area are achieved. Furthermore, the power consumption of the proposed wake-up receiver is scalable and is determined by the input signal sensitivity and data rate, which are configurable by the user. In a field test, the proposed wake-up receiver consumes $1~\mu \text{W}$ , which is smaller by 77% than that of a conventional ultrasound wake-up receiver at a comparable communication distance and data rate. Auteurs: Hiroshi Fuketa;Shinichi O’uchi;Takashi Matsukawa; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1027 - 1031 Editeur: IEEE Document complet vers site de l'éditeur
» A 0.3-V 1- $\mu \text{W}$ Super-Regenerative Ultrasound Wake-Up Receiver With Power Scalability
 Résumé:This brief presents an ultralow-power wake-up receiver using ultrasound for Internet of Things applications. To achieve both high sensitivity and low power consumption, we propose a Colpitts-oscillator-based super-regenerative receiver (COSR). Owing to the simple architecture of the proposed COSR, a lowest supply voltage operation of 0.3 V and a smallest area are achieved. Furthermore, the power consumption of the proposed wake-up receiver is scalable and is determined by the input signal sensitivity and data rate, which are configurable by the user. In a field test, the proposed wakeup receiver consumes 1 μW, which is smaller by 77% than that of a conventional ultrasound wake-up receiver at a comparable communication distance and data rate. Auteurs: Hiroshi Fuketa;Shinichi O’uchi;Takashi Matsukawa; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1027 - 1031 Editeur: IEEE Document complet vers site de l'éditeur
» A 0.65-V, 500-MHz Integrated Dynamic and Static RAM for Error Tolerant Applications
 Résumé:The diminishing returns provided by voltage scaling have led to a recent paradigm shift toward so-called “approximate computing,” where computation accuracy is traded off for cost in error-tolerant applications. In this paper, a novel approach to achieving the power–performance–area versus data integrity tradeoff is proposed by integrating robust static memory cells and error-prone dynamic cells within a single array. In addition, the resulting integrated dynamic and static random access memory (iD-SRAM) provides the ability to trade off power consumption and accuracy on-the-fly according to the current conditions and operating mode. A 4-kB iD-SRAM array was implemented in a low-power, 65-nm CMOS technology, providing as much as an 80% power reduction and a 20% area reduction as compared with standard approaches, when applied to a video decoder at 500 MHz. Auteurs: Amit Kazimirsky;Adam Teman;Noa Edri;Alexander Fish; Apparue dans: IEEE Transactions on Very Large Scale Integration Systems Date publication: 09.-2017, volume: 25, issue:9, pages: 2411 - 2418 Editeur: IEEE Document complet vers site de l'éditeur
» A 0.6V 75nW All-CMOS Temperature Sensor With 1.67m°C/mV Supply Sensitivity
 Résumé:This paper presents the design of a fully-integrated ultra-low-power temperature sensor applicable for use in wearable, environmental monitoring, and Internet-of-Things applications. Temperature is transduced in the proposed design by charging a pair of capacitors with proportional to or complementary to (proportional to absolute temperature or complementary to absolute temperature) current sources, and converting temperature-varying charging times to digital via a time-to-digital converter clocked by an on-chip temperature- and supply-stabilized 30-kHz relaxation oscillator. A low-voltage pseudo-differential dual-loop current reference generator is employed alongside inverter-based comparators to impart supply- and temperature-stable performance at low power. Fabricated in $0.18\mu \text{m}$ CMOS, the design operates at 0.6 V and consumes 75 nW at room temperature. Across a temperature range of 0 °C–100 °C, the sensor achieves a best-case (worst-case) temperature accuracy of +0.47 °C/−0.22 °C (+0.62 °C/−1.33 °C) and a resolution of 0.093 °C (0.1 °C). Across a supply range of 0.55–−0.85 V, the sensor achieves an inaccuracy of +0.19 °C/−0.28 °C. Auteurs: Xiaoyang Wang;Po-Han Peter Wang;Yuan Cao;Patrick P. Mercier; Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers Date publication: 09.-2017, volume: 64, issue:9, pages: 2274 - 2283 Editeur: IEEE Document complet vers site de l'éditeur
» A 160-GHz Switched Injection-Locked Oscillator for Phase and Amplitude Regenerative Sampling
 Résumé:This letter presents a switched injection-locked oscillator (SILO) operating at 160 GHz. The SILO utilizes positive feedback in a low-gain amplifier stage to achieve high regenerative gain for phase and amplitude information. The circuit is switched off every symbol period before the oscillator reaches its steady oscillation state to prevent the loss of information, then switched on again to receive the next symbol. This provides a viable solution for energy-efficient amplification in millimeter-wave communication systems, and is the fastest reported circuit of its kind. Fabricated in a 0.13- $\mu \text{m}$ SiGe BiCMOS technology ( $f_{T}=300$ GHz), the chip requires an area of 0.64 mm2 and provides 18.4 dB of regenerative gain, while consuming only 6.6 mW of dc power in SILO operation, thus outperforming amplifiers in this frequency range in terms of power consumption. Auteurs: Hatem Ghaleb;Paolo Valerio Testa;Stefan Schumann;Corrado Carta;Frank Ellinger; Apparue dans: IEEE Microwave and Wireless Components Letters Date publication: 09.-2017, volume: 27, issue:9, pages: 821 - 823 Editeur: IEEE Document complet vers site de l'éditeur
» A 2.4-GHz CMOS Common-Gate Combining Power Amplifier With Load Impedance Adaptor
 Résumé:A CMOS common-gate (CG) combining power amplifier is introduced, which has a simple load impedance adaptor. The CG stage of a cascode amplifier consists of a main amplifier with a load impedance adapter and an auxiliary amplifier with a phase compensator, which are biased for classes AB and C, respectively. The proposed configuration not only increases the efficiency of the power amplifier (PA) at back-off powers, but also increases the linearity at high output powers by canceling AM–AM and AM–PM nonlinearities of the main amplifier with those of the auxiliary amplifier. A load impedance adaptor can be used to match two different optimum load impedances of the main and auxiliary amplifiers simultaneously. A phase compensator is introduced to match the output phases of both amplifiers. It has a die size of $0.9 \times 1.63$ mm2 operates at 2.484 GHz with a 3.3 V supply, which is implemented with the 0.18- $\mu \text{m}$ CMOS technology. It shows a linear output power of 22.1 dBm with a PAE of 32% for an 802.11 n signal at error vector magnitude (EVMs) of −25 dB, and it also shows apparent efficiency improvements at back-off powers. Auteurs: Yoonsoo Jin;Songcheol Hong; Apparue dans: IEEE Microwave and Wireless Components Letters Date publication: 09.-2017, volume: 27, issue:9, pages: 836 - 838 Editeur: IEEE Document complet vers site de l'éditeur
» A 2.4-GHz Super-Regenerative Transceiver With Selectivity-Improving Dual Q-Enhancement Architecture and 102- $\mu \text{W}$ All-Digital FLL
 Résumé:A multichannel super-regenerative transceiver with a selectivity-improving dual Q-enhancement architecture and a 102- $\mu \text{W}$ all-digital frequency-locked loop (FLL) is presented for bio-signal sensor nodes covering the 2.36–2.4-GHz medical band and 2.4-GHz industrial-scientic-medical (ISM) band. The conventional super-regenerative receiver suffers from the weak selectivity, and its performance is deteriorated in proportion to an increase of the data rate. The proposed receiver implements dual Q-enhancement operation of the low-noise amplifier (LNA) and super-regenerative oscillator (SRO) and improves the interferer rejection without data rate dependence. For channel frequency synthesis, an all-digital FLL is integrated. The digital fine-tuning method obviates the control voltage discharging issue of oscillator in analog phase locked loop (PLL) during SRO quenching operation, and the simplified all-digital frequency loop reduces the frequency synthesizer power in the ultralow-power sensor nodes. Implemented in 90-nm CMOS technology, the proposed transceiver occupies an effective die size of 1.81 mm2 and achieves an sensitivity of −82 dBm at 1-Mb/s/ $10^{-3}$ bit error rate (BER) and interference selectivity of 32 dB at a 1-Mb/s/10-MHz offset while consumping $102~\mu \text{W}$ at the all-digital FLL and 0.93/2.37 nJ/b at receiver/transmitter, respectively. Auteurs: Seong Joong Kim;DongSoo Lee;Kang-Yoon Lee;Sang-Gug Lee; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3287 - 3298 Editeur: IEEE Document complet vers site de l'éditeur
» A 2.6 $\mu \text{W}$ –1.2 mW Autonomous Electromagnetic Vibration Energy Harvester Interface IC with Conduction-Angle-Controlled MPPT and up to 95% Efficiency
 Résumé:This paper presents an IC optimized to interface small-scaled electromagnetic vibration energy harvesters. The interface IC tracks the optimum conduction angle of the implemented active AC–DC input stage, enabling maximum power point tracking without the need for a system clock, harvester disconnection, or any external sensor. The optimum conduction angle tracking control nominally requires 815 nW. An energy buffer can autonomously be charged via the interface, employing a hysteretic input voltage-controlled inductive DC–DC boost converter, to 4.2 V for IC input powers between 2.6 $\mu \text{W}$ and 1.2 mW with a peak power conversion efficiency of 95%. The 4.2 V is even reached when harvesting from weak vibrations of only 0.2 m/s2 acceleration peak amplitudes and input voltages of around 570 mV. Buffer charging with up to 91% of the maximal available harvester power is accomplished, and cold startup is enabled. The IC prototype in 0.35 $\mu \text{m}$ CMOS draws a quiescent current of 272 nA from the energy buffer at 4.2 V and a quiescent power of 639 nW at 3 V. In order to supply an application, such as a wireless sensor node, the IC can be configured to generate a regulated voltage and to ensure reliable operation by means of an overvoltage protection. Auteurs: Joachim Leicht;Yiannos Manoli; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2448 - 2462 Editeur: IEEE Document complet vers site de l'éditeur
» A 2.6 $\mu \text{W}$ –1.2 mW Autonomous Electromagnetic Vibration Energy Harvester Interface IC with Conduction-Angle-Controlled MPPT and up to 95% Efficiency
 Résumé:This paper presents an IC optimized to interface small-scaled electromagnetic vibration energy harvesters. The interface IC tracks the optimum conduction angle of the implemented active AC–DC input stage, enabling maximum power point tracking without the need for a system clock, harvester disconnection, or any external sensor. The optimum conduction angle tracking control nominally requires 815 nW. An energy buffer can autonomously be charged via the interface, employing a hysteretic input voltage-controlled inductive DC–DC boost converter, to 4.2 V for IC input powers between 2.6 $\mu \text{W}$ and 1.2 mW with a peak power conversion efficiency of 95%. The 4.2 V is even reached when harvesting from weak vibrations of only 0.2 m/s2 acceleration peak amplitudes and input voltages of around 570 mV. Buffer charging with up to 91% of the maximal available harvester power is accomplished, and cold startup is enabled. The IC prototype in 0.35 $\mu \text{m}$ CMOS draws a quiescent current of 272 nA from the energy buffer at 4.2 V and a quiescent power of 639 nW at 3 V. In order to supply an application, such as a wireless sensor node, the IC can be configured to generate a regulated voltage and to ensure reliable operation by means of an overvoltage protection. Auteurs: Joachim Leicht;Yiannos Manoli; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2448 - 2462 Editeur: IEEE Document complet vers site de l'éditeur
» A 2.6 $\mu \text{W}$ –1.2 mW Autonomous Electromagnetic Vibration Energy Harvester Interface IC with Conduction-Angle-Controlled MPPT and up to 95% Efficiency
 Résumé:This paper presents an IC optimized to interface small-scaled electromagnetic vibration energy harvesters. The interface IC tracks the optimum conduction angle of the implemented active AC–DC input stage, enabling maximum power point tracking without the need for a system clock, harvester disconnection, or any external sensor. The optimum conduction angle tracking control nominally requires 815 nW. An energy buffer can autonomously be charged via the interface, employing a hysteretic input voltage-controlled inductive DC–DC boost converter, to 4.2 V for IC input powers between 2.6 $\mu \text{W}$ and 1.2 mW with a peak power conversion efficiency of 95%. The 4.2 V is even reached when harvesting from weak vibrations of only 0.2 m/s2 acceleration peak amplitudes and input voltages of around 570 mV. Buffer charging with up to 91% of the maximal available harvester power is accomplished, and cold startup is enabled. The IC prototype in 0.35 $\mu \text{m}$ CMOS draws a quiescent current of 272 nA from the energy buffer at 4.2 V and a quiescent power of 639 nW at 3 V. In order to supply an application, such as a wireless sensor node, the IC can be configured to generate a regulated voltage and to ensure reliable operation by means of an overvoltage protection. Auteurs: Joachim Leicht;Yiannos Manoli; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2448 - 2462 Editeur: IEEE Document complet vers site de l'éditeur
» A 2.6 $\mu \text{W}$ –1.2 mW Autonomous Electromagnetic Vibration Energy Harvester Interface IC with Conduction-Angle-Controlled MPPT and up to 95% Efficiency
 Résumé:This paper presents an IC optimized to interface small-scaled electromagnetic vibration energy harvesters. The interface IC tracks the optimum conduction angle of the implemented active AC-DC input stage, enabling maximum power point tracking without the need for a system clock, harvester disconnection, or any external sensor. The optimum conduction angle tracking control nominally requires 815 nW. An energy buffer can autonomously be charged via the interface, employing a hysteretic input voltage-controlled inductive DC-DC boost converter, to 4.2 V for IC input powers between 2.6 μW and 1.2 mW with a peak power conversion efficiency of 95%. The 4.2 V is even reached when harvesting from weak vibrations of only 0.2 m/s2 acceleration peak amplitudes and input voltages of around 570 mV. Buffer charging with up to 91% of the maximal available harvester power is accomplished, and cold startup is enabled. The IC prototype in 0.35 μm CMOS draws a quiescent current of 272 nA from the energy buffer at 4.2 V and a quiescent power of 639 nW at 3 V. In order to supply an application, such as a wireless sensor node, the IC can be configured to generate a regulated voltage and to ensure reliable operation by means of an overvoltage protection. Auteurs: Joachim Leicht;Yiannos Manoli; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2448 - 2462 Editeur: IEEE Document complet vers site de l'éditeur
» A 2.6 $\mu \text{W}$ –1.2 mW Autonomous Electromagnetic Vibration Energy Harvester Interface IC with Conduction-Angle-Controlled MPPT and up to 95% Efficiency
 Résumé:This paper presents an IC optimized to interface small-scaled electromagnetic vibration energy harvesters. The interface IC tracks the optimum conduction angle of the implemented active AC-DC input stage, enabling maximum power point tracking without the need for a system clock, harvester disconnection, or any external sensor. The optimum conduction angle tracking control nominally requires 815 nW. An energy buffer can autonomously be charged via the interface, employing a hysteretic input voltage-controlled inductive DC-DC boost converter, to 4.2 V for IC input powers between 2.6 μW and 1.2 mW with a peak power conversion efficiency of 95%. The 4.2 V is even reached when harvesting from weak vibrations of only 0.2 m/s2 acceleration peak amplitudes and input voltages of around 570 mV. Buffer charging with up to 91% of the maximal available harvester power is accomplished, and cold startup is enabled. The IC prototype in 0.35 μm CMOS draws a quiescent current of 272 nA from the energy buffer at 4.2 V and a quiescent power of 639 nW at 3 V. In order to supply an application, such as a wireless sensor node, the IC can be configured to generate a regulated voltage and to ensure reliable operation by means of an overvoltage protection. Auteurs: Joachim Leicht;Yiannos Manoli; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2448 - 2462 Editeur: IEEE Document complet vers site de l'éditeur
» A 27-Gb/s Time-Interleaved Duobinary Transmitter Achieving 1.44-mW/Gb/s FOM in 65-nm CMOS
 Résumé:A time-interleaved duobinary transmitter featuring four-way data retiming and a simplified latch + D flip-flop topology to improve the power efficiency and opening of the data eye is reported. A modified bridged shunt-peaking load using a grounded active inductor is also introduced to enhance the operational speed area efficiently. Finally, the two multiplexers, serving directly as the output driver, are summed in the current domain to avoid an extra adder. The prototype exhibits a figure-of-merit of 1.44 mW/Gb/s at 27 Gb/s, and the die area is merely 0.027 mm2 in 65-nm CMOS. Auteurs: Yong Chen;Pui-In Mak;Chirn Chye Boon;Rui P. Martins; Apparue dans: IEEE Microwave and Wireless Components Letters Date publication: 09.-2017, volume: 27, issue:9, pages: 839 - 841 Editeur: IEEE Document complet vers site de l'éditeur
» A 3-RSR Haptic Wearable Device for Rendering Fingertip Contact Forces
 Résumé:A novel wearable haptic device for modulating contact forces at the fingertip is presented. Rendering of forces by skin deformation in three degrees of freedom (DoF), with contact—no contact capabilities, was implemented through rigid parallel kinematics. The novel asymmetrical three revolute-spherical-revolute (3-RSR) configuration allowed compact dimensions with minimum encumbrance of the hand workspace. The device was designed to render constant to low frequency deformation of the fingerpad in three DoF, combining light weight with relatively high output forces. A differential method for solving the non-trivial inverse kinematics is proposed and implemented in real time for controlling the device. The first experimental activity evaluated discrimination of different fingerpad stretch directions in a group of five subjects. The second experiment, enrolling 19 subjects, evaluated cutaneous feedback provided in a virtual pick-and-place manipulation task. Stiffness of the fingerpad plus device was measured and used to calibrate the physics of the virtual environment. The third experiment with 10 subjects evaluated interaction forces in a virtual lift-and-hold task. Although with different performance in the two manipulation experiments, overall results show that participants better controlled interaction forces when the cutaneous feedback was active, with significant differences between the visual and visuo-haptic experimental conditions. Auteurs: Daniele Leonardis;Massimiliano Solazzi;Ilaria Bortone;Antonio Frisoli; Apparue dans: IEEE Transactions on Haptics Date publication: 09.-2017, volume: 10, issue:3, pages: 305 - 316 Editeur: IEEE Document complet vers site de l'éditeur
» A 32 kb 0.35–1.2 V, 50 MHz–2.5 GHz Bit-Interleaved SRAM With 8 T SRAM Cell and Data Dependent Write Assist in 28-nm UTBB-FDSOI CMOS
 Résumé:An optimized co-design of SRAM cell, assist schemes, and layout is proposed to achieve wide voltage range operation of SRAM from 0.35–1.2 V at all process corners. A differential read asymmetric 8 T memory cell and a data dependent differential supply and body modulation write assist scheme are proposed. We also propose a layout that reduces metal capacitance of wordlines by 54% and also enables bit-interleaving. The proposed assist scheme can be combined with conventional assist schemes to further lower minimum write operational voltage of the SRAM by 70–130 mV at iso-performance without causing reliability concerns. A 32 kb instance is fabricated in 28-nm UTBB-FDSOI technology and efficiency of the proposed scheme is demonstrated with lowest write voltage of 0.32 V. Multiple read assist schemes have been used to simultaneously lower read voltage to 0.35 V. 50 MHz operation is measured when integrated in a DSP processor at 0.358 V. Low voltage and wide voltage range figure of merits are also defined to benchmark the proposed solutions with other works. Auteurs: Anuj Grover;G. S. Visweswaran;Chittoor R. Parthasarathy;Mohammad Daud;David Turgis;Bastien Giraud;Jean-Philippe Noel;Ivan Miro-Panades;Guillaume Moritz;Edith Beigné;Philippe Flatresse;Promod Kumar;Shamsi Azmi; Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers Date publication: 09.-2017, volume: 64, issue:9, pages: 2438 - 2447 Editeur: IEEE Document complet vers site de l'éditeur
» A 38 pJ/b Optimal Soft-MIMO Detector
 Résumé:An optimal soft multiple-input multiple-output (MIMO) detector is proposed with linear complexity for a general spatial multiplexing system with two transmitting symbols and $\boldsymbol {N_{R}\ge 2}$ receiving antennas. The computational complexity of the proposed scheme is independent of the operating signal-to-noise ratio and grows linearly with the constellation order. It provides the soft maximum-likelihood solution using an efficient log-likelihood ratio calculation method, avoiding the exhaustive search on all the candidate nodes. Moreover, an efficient pipelined hardware implementation of the detection algorithm is proposed, which is fabricated and fully tested in a 130-nm CMOS technology. Operating at 1.2 V supply with 412-MHz clock, the chip achieves up to 5 Gb/s throughput with 192-mW power dissipation and an energy efficiency of 38 pJ/b, showing great potential to be used in next generation Gbps wireless systems. The proposed MIMO detector is perfectly suitable to be applied to the long-term evolution modem as well as Wi-Fi and WiGig devices with more than 1 RF chain. Synthesis results in a 90-nm CMOS technology demonstrate that the design can operate at a sustained throughput of 6.2 Gb/s and an energy efficiency of 28 pJ/b at 1.2 V supply. For applications demanding a lower throughput regime, the core can operate at 0.9 V supply consuming 42 mW providing a throughput of 1 Gb/s.11U.S. patent issued in 2009. Auteurs: M. Shabany;R. Doostnejad;M. Mahdavi;P. Glenn Gulak; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1062 - 1066 Editeur: IEEE Document complet vers site de l'éditeur
» A 40-Gb/s 14-mW CMOS Wireline Receiver
 Résumé:A 40-Gb/s receiver includes a continuous-time linear equalizer, a discrete-time linear equalizer, a two-tap decision-feedback equalizer, a clock and data recovery circuit, and a one-to-four deserializer. Hardware minimization and charge steering techniques are extensively used to reduce the power consumption by a factor of ten. Fabricated in 45-nm CMOS technology, the receiver exhibits a bathtub curve opening of 0.28 UI with a recovered clock jitter of 0.5 psrms. Auteurs: Abishek Manian;Behzad Razavi; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2407 - 2421 Editeur: IEEE Document complet vers site de l'éditeur
» A 5-GHz WLAN RF CMOS Power Amplifier With a Parallel-Cascoded Configuration and an Active Feedback Linearizer
 Résumé:This paper presents a highly linear cascode power amplifier (PA) for 5-GHz 802.11ac (wireless local area network) WLAN applications, which is fabricated with a 0.13- $\mu \text{m}$ standard RF CMOS process. A parallel-cascoded configuration is proposed to cancel out third and fifth intermodulation distortions and third harmonic distortion (HD) due to drain–source current nonlinearity. This also reduces distortions due to drain–source and gate-source nonlinear capacitances at both common source (CS) and common gate (CG) stages. The configuration allows the amplifier linear characteristics to be robust against gate node voltage variations of CG transistors compared to previous multigated transistor linearization methods, because the CG transistors always remain in the saturation region and the nonlinearities of capacitances associated with CG transistors cancel each other under a wide range of output powers. In addition, an active feedback linearizer is applied to improve AM–AM and the power-added efficiency (PAE) at high output powers. At 5.15 GHz, the proposed PA is tested with a 256-quadrature amplitude modulation WLAN 802.11ac signal source without digital predistortions. The output powers satisfying the stringent linearity, a −35-dB error vector magnitude, are 17.8, 17.3, and 15.6 dBm with 11.5%, 10.4%, and 7.5% PAEs at 20, 40, and 80 MHz, respectively. Auteurs: Seunghoon Kang;Donghyun Baek;Songcheol Hong; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3230 - 3244 Editeur: IEEE Document complet vers site de l'éditeur
» A 50 Gb/s 190 mW Asymmetric 3-Tap FFE VCSEL Driver
 Résumé:This paper describes the design of an energy-efficient vertical-cavity surface-emitting laser (VCSEL) driver circuit implemented in a 130 nm SiGe BiCMOS technology. The driver features a 3-tap feed-forward equalizer where positive and negative peaks are added to the main signal to compensate for the low-pass characteristic of VCSELs. The circuit is also able to generate asymmetric pre-emphasis to counteract the VCSEL nonlinearity. Bonded to an 18 GHz VCSEL, the driver can reach an error-free (bit error rate < 10−12) optical data rate of 50 Gb/s with an horizontal eye opening better than 0.2 unit interval using a 22 GHz photoreceiver without equalization, retiming, and limiting amplifier at the receiver side. At 48 Gb/s, the horizontal eye opening is 0.5 unit interval. The circuit dissipates only 190 mW from a dual supply of 2.5 and 3.3 V, including the VCSEL power. To the best of the authors’ knowledge, this is the fastest common-cathode VCSEL driver with lowest power consumption for data rates higher than 35 Gb/s. Thanks to the active delay line and the application of vertical inductor, the driver is very compact with an active area of only 0.036 mm2 including the inductor. Auteurs: Guido Belfiore;Mahdi Khafaji;Ronny Henker;Frank Ellinger; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2422 - 2429 Editeur: IEEE Document complet vers site de l'éditeur
» A 5GHz Digital Fractional- $N$ PLL Using a 1-bit Delta–Sigma Frequency-to-Digital Converter in 65 nm CMOS
 Résumé:A highly digital two-stage fractional- $N$ phase-locked loop (PLL) architecture utilizing a first-order 1-bit $\Delta \!\Sigma$ frequency-to-digital converter (FDC) is proposed and implemented in a 65nm CMOS process. Performance of the first-order 1-bit $\Delta \!\Sigma$ FDC is improved by using a phase interpolator-based fractional divider that reduces phase quantizer input span and by using a multiplying delay-locked loop that increases its oversampling ratio. We also describe an analogy between a time-to-digital converter (TDC) and a $\Delta \!\Sigma$ FDC followed by an accumulator that allows us to leverage the TDC-based PLL analysis techniques to study the impact of $\Delta \!\Sigma$ FDC characteristics on $\Delta \!\Sigma$ FDC-based fractional- $N$ PLL (FDCPLL) performance. Utilizing proposed techniques, a prototype PLL achieves 1 MHz bandwidth, −101.6 dBc/Hz in-band phase noise, and ${\textrm {1.22 ps}_{\textrm {rms}}}$ (1 kHz–40 MHz) jitter while generating 5.031GHz output from 31.25MHz reference clock input. For the same output frequency, the stand-alone second-stage fractional- $N$ FDCPLL achieves 1MHz bandwidth, −106.1dBc/Hz in-band phase noise, and ${\textrm {403 fs}_{\textrm {rms}}-$ jitter with a 500MHz reference clock input. The two-stage PLL consumes 10.1mW power from a 1V supply, out of which 7.1 mW is consumed by the second-stage FDCPLL. Auteurs: Mrunmay Talegaonkar;Tejasvi Anand;Ahmed Elkholy;Amr Elshazly;Romesh Kumar Nandwana;Saurabh Saxena;Brian Young;Woo-Seok Choi;Pavan Kumar Hanumolu; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2306 - 2320 Editeur: IEEE Document complet vers site de l'éditeur
» A 7.1-mW $K/K_{a}$ -Band Mixer With Configurable Bondwire Resonators in 65-nm CMOS
 Résumé:A low-power (LP) $K$ / $K_{a}$ -band mixer with configurable capability is proposed in this paper. The mixer integrates a broadband transconductor stage, bondwire resonators, a broadband local oscillator balun, and a broadband switching stage. The bondwire resonators not only work as a balun for single-ended to differential conversion between the transconductor stage and the switching stage, but they can also be configured to have two or three resonators by controlling the number of bonding bondwires during the chip packaging process. These two and three resonators intentionally designed to have weak and strong magnetic couplings with each other, enable the mixer to exhibit narrowband and broadband frequency responses, respectively. Realized in a 65-nm LP CMOS technology, the mixers configured to have two and three resonators that show the measured conversion gains of 17.2 and 15.5 dB while giving 3- and 5-dB bandwidths from 22.5 to 28.5 and 21.5 to 32.5 GHz, respectively. The measured input third-order intercept points, noise figures, and port-to-port isolations of the mixers with two and three resonators are better than −2.7 and −1.9 dBm, 11.2 and 11 dB, and 25.6 and 25.7 dB, within the bandwidths, respectively. The mixer only consumes 7.1 mW from a 1.2-V supply. Auteurs: Chun-Hsing Li;Chun-Lin Ko;Ming-Ching Kuo;Da-Chiang Chang; Apparue dans: IEEE Transactions on Very Large Scale Integration Systems Date publication: 09.-2017, volume: 25, issue:9, pages: 2635 - 2648 Editeur: IEEE Document complet vers site de l'éditeur
» A 76- to 81-GHz Multi-Channel Radar Transceiver
 Résumé:This paper presents a packaged 76- to 81-GHz transceiver chip implemented in SiGe BiCMOS for both long-range and short-range automotive radars. The chip contains a two-channel transmitter (TX), a six-channel receiver (RX), a local-oscillator (LO) chain, and built-in self-test (BIST) circuitry. Each transmit channel includes multiple variable-gain amplifiers and a two-stage power amplifier. Measured on-die output power per channel is +18 dBm at 25 °C, decreasing to +16 dBm at 125 °C. Each receive channel includes a current-mode mixer, followed by intermediate-frequency buffers. At 25 °C, measured on-die noise figure is 10–11 dB, conversion gain is 14–15 dB, and input 1-dB compression point exceeds +1 dBm. An integrated LO chain drives the transmit and receive chains and includes an 18.5- to 20.6-GHz voltage-controlled oscillator connected to cascaded frequency doublers and a divide-by-four prescaler. At 25 °C, measured phase noise is −100 dBc/Hz at 1-MHz offset from a 77-GHz carrier. Integrated BIST circuits enable the measurement of signal power, RX gain, channel-to-channel phase, and internal temperature. The chip is flip-chip packaged into a ball-grid array and extracted interconnect loss for the package is 1.5 to 2 dB. Total power consumption for the chip is 1.8 W from 3.3 V for a single-TX, six-RX mode. Auteurs: Takeji Fujibayashi;Yohsuke Takeda;Weihu Wang;Yi-Shin Yeh;Willem Stapelbroek;Seiji Takeuchi;Brian Floyd; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2226 - 2241 Editeur: IEEE Document complet vers site de l'éditeur
» A 950 nW Analog-Based Data Reduction Chip for Wearable EEG Systems in Epilepsy
 Résumé:Long-term electroencephalogram (EEG) monitoring is an important tool used for the diagnosis of epilepsy. Truly Wearable EEG can be considered as the future of ambulatory EEG units, which are the current standard for long-term EEG monitoring. Replacing these short lifetime, bulky units with long-lasting miniature and wearable devices which can be easily worn by patients will result in more EEG data being acquired for longer monitoring periods. This paper presents an analog-based data reduction integrated circuit that would reduce the amount of power required to transmit EEG data by identifying the sections of data that are interesting for diagnostic purposes while discarding the background activity. Using the data reduction system as part of a miniature wireless, EEG monitoring unit would yield significant reductions in power consumption since the transmitter will only be switched ON based on the data reduction system output. A system prototype chip has been fabricated in a 0.35 $\mu \text{m}$ CMOS process. The system consumes 760 nA from a 1.25 V supply and is able to achieve a sensitivity of 87%, while transmitting 45% of the overall EEG data. Auteurs: Saam Iranmanesh;Esther Rodriguez-Villegas; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2362 - 2373 Editeur: IEEE Document complet vers site de l'éditeur
» A Bayesian Approach to Camouflaged Moving Object Detection
 Résumé:Moving object detection is about foreground and background separation based on motion detection. Detecting moving objects from similarly colored background (known as camouflage problem) has been a long-standing open question in this field. Discriminative modeling (DM), which focuses on enhancing the performance to distinguish foreground from background with discriminative features and well-designed classifiers, has been widely used for moving object detection. However, DM may tend to fail when encountering the camouflage problem, as the class separability in camouflaged areas is generally poor. In this paper, we propose a new strategy, camouflage modeling (CM), to identify camouflaged foreground pixels. In view of the fact that camouflage involves both foreground and background, we need to model both the background and the foreground, and compare them in a well-designed way in camouflage detection. Specifically, we develop a global model for the background, and an integration of global and local models for the foreground, respectively. Based on both background and foreground models, we introduce a factor to measure the degree of camouflage, and further identify truly camouflaged areas. In view of the fact that a moving object is usually composed of both camouflaged and noncamouflaged areas, CM and DM are fused in a Bayesian framework to perform complete object detection. Experiments are conducted on testing sequences to demonstrate the effectiveness of the proposed algorithm. Auteurs: Xiang Zhang;Ce Zhu;Shuai Wang;Yipeng Liu;Mao Ye; Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology Date publication: 09.-2017, volume: 27, issue:9, pages: 2001 - 2013 Editeur: IEEE Document complet vers site de l'éditeur
» A Bilevel Optimization Model for Risk Assessment and Contingency Ranking in Transmission System Reliability Evaluation
 Résumé:This paper presents a bilevel optimization model for the risk assessment of transmission systems. Specifically, the lower level model is expected to provide a generation redispatch by minimizing the total load shedding, and the upper-level model is to maximize the severity risk by constructing a binary optimization model to identify the worst N-k contingency. To further reduce the complexity of the proposed model, the logarithmic transformation and linearization techniques are utilized, leading to a general mixed integer linear programming. In addition, a recursive method is proposed for contingency ranking based on the bilevel optimization model. Compared with the benchmark analytic method, the proposed method does not need to enumerate every contingency, reducing the computational burden. In contrast to the traditional Monte Carlo Simulation method, the proposed method can give as precise a risk assessment result as the analytic method and has higher evaluation efficiency. Numerical results on three test systems verify the effectiveness of the proposed method. Auteurs: Tao Ding;Cheng Li;Chao Yan;Fangxing Li;Zhaohong Bie; Apparue dans: IEEE Transactions on Power Systems Date publication: 09.-2017, volume: 32, issue:5, pages: 3803 - 3813 Editeur: IEEE Document complet vers site de l'éditeur
» A Bio-Inspired Analog Gas Sensing Front End
 Résumé:With the Internet of Things (IoT) paradigm promising to deploy trillions of sensors, the search is on for effective means to efficiently derive useful information from the flood of sensor data through efficient hardware preprocessing. Of particular interest are computational paradigms that get their inspiration from biological sensory systems that seamlessly extract relevant information through highly efficient analog signal processing. Functions, such as feature extraction, learning, or recognition, could especially benefit from bio-inspired architectures. As an example in the case, this paper presents a bio-inspired analog gas sensing frontend for an artificial olfactory system. The analog front end implements a novel trainable feature extraction algorithm for metal-oxide gas sensor arrays. The algorithm extracts one composite feature of all analytes by performing the gradient decent algorithm during training and transforms the sensor responses into concentration-invariant spike patterns. An integrated circuit realization of the algorithm, implemented in a 65-nm CMOS technology, supports six-input channels, uses subthreshold analog circuits, and consumes 519-nW/channel in the training mode, and 463-nW/channel in the recognition mode. Auteurs: Ping-Chen Huang;Jan M. Rabaey; Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers Date publication: 09.-2017, volume: 64, issue:9, pages: 2611 - 2623 Editeur: IEEE Document complet vers site de l'éditeur
» A Broadband Near-Field UHF RFID Reader Antenna With Low Far-Field Gain
 Résumé:A broadband magnetic coupling antenna with low far-field gain for ultrahigh frequency radio frequency identification near-field applications is presented in this communication. The proposed antenna is consisted of a number of loop units and each unit has in-phase current along the loop. It generates a strong uniformly distributed magnetic field over a large interrogation. To meet different scenarios, the interrogated area can be adjusted by changing the number of units. The proposed antenna has low far-field gain and broadband characteristics. Mechanism analysis is carried out to provide the guidelines for the antenna design. As an example, a 10-unit antenna has been fabricated and measured. The experimental results show that the antenna achieves the impedance matching over the frequency range from 740 to 4600 MHz. And the proposed antenna achieves 100% reading rate with 140 button tags in the region of 100 mm $\times750$ mm $\times12$ mm. Auteurs: Yuan Yao;Yishan Liang;Junsheng Yu;Xiaodong Chen; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4869 - 4874 Editeur: IEEE Document complet vers site de l'éditeur
» A Butterfly-Based Direct Integral-Equation Solver Using Hierarchical LU Factorization for Analyzing Scattering From Electrically Large Conducting Objects
 Résumé:A butterfly-based direct combined-field integral-equation (CFIE) solver for analyzing scattering from electrically large, perfect electrically conducting objects is presented. The proposed solver leverages the butterfly scheme to compress blocks of the hierarchical LU-factorized discretized CFIE operator and uses randomized butterfly reconstruction schemes to expedite the factorization. The memory requirement and computational cost of the direct butterfly-CFIE solver scale as $O(N\log ^{2}N)$ and $O(N^{1.5}\log N)$ , respectively. These scaling estimates permit significant memory and CPU savings when compared to those realized by low-rank decomposition-based solvers. The efficacy and accuracy of the proposed solver are demonstrated through its application to the analysis of scattering from canonical and realistic objects involving up to 14 million unknowns. Auteurs: Han Guo;Yang Liu;Jun Hu;Eric Michielssen; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4742 - 4750 Editeur: IEEE Document complet vers site de l'éditeur
» A Cantilever Vibrational Generator Based on an Fe–Co Beam
 Résumé:Typical vibrational harvesters using a high-permeability beam in a cantilever configuration exploit the field generated by a couple of counter-polarized permanent magnets facing the vibrating strip at the free end. Such a canonical position of the magnets does not permit one, however, to highlight the importance of the bias field pattern. A proof of concept archetype is realized in this paper, by which the influence of the magnetization profile along the length of the vibrating ferromagnetic beam is put in evidence. It demonstrates, in particular, that significant variations, even by a factor of three, of the output power can be obtained by a modification of the magnets arrangement. We discussed in this paper the behavior of a cantilever-based generator, where an Fe–Co high-permeability beam is made to vibrate inside an inhomogeneous magnetic field generated by permanent magnets, whose arrangement can modified in order to vary the magnetization profile along the vibrating laminae. The effects of such a profile are measured and analyzed by means of a simple 2-D numerical model, showing that the generated power can be enhanced by conveniently acting on the magnets configuration. The measurements show that, with a host acceleration of $5g$ rms ( $g = 9.81$ m/ $\text{s}^{2}$ ), a 6.72 mW time average output power is obtained for operating frequencies around 60 Hz. Auteurs: Mauro Zucca;Arash Hadadian;Fausto Fiorillo;Mario Chiampi; Apparue dans: IEEE Transactions on Magnetics Date publication: 09.-2017, volume: 53, issue:9, pages: 1 - 7 Editeur: IEEE Document complet vers site de l'éditeur
» A Capacitor-DAC-Based Technique For Pre-Emphasis-Enabled Multilevel Transmitters
 Résumé:This brief presents a capacitor digital-to-analog converter (DAC) based technique that is suitable for pre-emphasis-enabled multilevel wireline transmitter design in voltage mode. Detailed comparisons between the proposed technique and conventional direct-coupling-based as well as resistor-DAC-based multilevel transmitter design techniques are given, revealing potential benefits in terms of speed, linearity, implementation complexity, and also power consumption. A PAM-4 transmitter with 2-Tap feed-forward equalization adopting the proposed technique is implemented in 65-nm CMOS technology. It achieves a 25-Gb/s data rate and energy efficiency of 2 mW/Gb/s. Auteurs: Boyu Hu;Yuan Du;Rulin Huang;Jeffrey Lee;Young-Kai Chen;Mau-Chung Frank Chang; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1012 - 1016 Editeur: IEEE Document complet vers site de l'éditeur
» A Case for Nonconvex Distributed Optimization in Large-Scale Power Systems
 Résumé:Distributed optimization for solving nonconvex optimal power flow (OPF) problems in power systems has attracted considerable attention in the last decade. Most studies are based on the geographical decomposition of the IEEE test systems for verifying the feasibility of the proposed approaches. However, it is not clear if one can extrapolate from these studies that similar approaches can also be applied to very large-scale real-world systems. In this paper, we show, for the first time, that distributed optimization can be effectively applied to a large-scale real transmission network, namely, the Polish 2383-bus system for which no predefined partitions exist, by using a recently developed partitioning technique. More specifically, the problem solved is the ac OPF problem with geographical decomposition of the network using the alternating direction method of multipliers (ADMM) method in conjunction with the partitioning technique. Through extensive simulations and analytical studies, we show that with the presented partitioning technique the convergence performance of the ADMM method can be improved substantially, which enables the application of distributed approaches to very large-scale systems. Auteurs: Junyao Guo;Gabriela Hug;Ozan K. Tonguz; Apparue dans: IEEE Transactions on Power Systems Date publication: 09.-2017, volume: 32, issue:5, pages: 3842 - 3851 Editeur: IEEE Document complet vers site de l'éditeur
» A Centralized Optimization Solution for Application Layer Multicast Tree
 Résumé:Application layer multicast (ALM) is an effective group communication method. The ALM tree is usually built in a distributed manner because of its good scalability. However, the distributed ALM solution sometimes produces a low performance delivery tree. In this paper, we propose an ALM tree optimization solution, named ALMTO, for multicast applications, in particular, those with a large number of concurrent users. ALMTO manages and optimizes the ALM tree in the following four steps: 1) periodic collection of related structure information, based on a proposed structure report domain model and special tree structure; 2) construction and maintenance of a logical ALM tree, in terms of the collected structure information; 3) central computation of the ALM tree optimization scheme, according to the logical ALM tree and optimization objective corresponding to the specific multicast application; and 4) reshaping of the real ALM tree in terms of the optimization scheme. We analyze the problem of the centralized tree optimization scheme orchestration and present an effective solution that can adapt to the dynamics of group members. We also present two approaches: 1) degree-bounded connection-keeping tree transformation and 2) ring-based data compensation to ensure that the ALM tree can be reliably transformed. Auteurs: Xinchang Zhang;Lu Wang;Ye Li;Meng Sun; Apparue dans: IEEE Transactions on Network and Service Management Date publication: 09.-2017, volume: 14, issue:3, pages: 771 - 785 Editeur: IEEE Document complet vers site de l'éditeur
» A Class of Distance-Optimal Binary Linear Codes With Flexible Parameters
 Résumé:Binary linear codes with good parameters have wide applications in data storage, communications, and information security. Inspired by the idea proposed by Ding recently and based on the Boolean functions with bivariate polynomial representation in even number of variables, we construct a class of two-weight binary linear codes with length $(2^{k}-1)e$ , dimension $2k$ , and minimum distance $2^{k-1}(e-1)$ , where $k\ge 2$ and $e$ is an arbitrary integer with $2^{k}-k » A CMOS Seawater Salinity to Digital Converter for IoT Applications of Fish Farms  Résumé:This paper proposes a complementary metal–oxide–semiconductor (CMOS) seawater-salinity-to-digital converter for Internet of Things (IoT) applications in fish farms. In contrast to previous studies, the proposed converter not only is suitable for processing seawater salinity but also has immunity to environmental low-frequency noise. Another innovation is that it can be easily delivered through transmission media before the IoT. The performance and functions of the proposed converter were successfully verified through measurements. The measured salinity range was 20–80 g/L, and the corresponding measured signal-to-noise-distortion ratio was 81.3–62.5 dB. The proposed converter is, therefore, suitable for IoT applications in salinity-monitoring devices. Auteurs: Cheng-Ta Chiang; Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers Date publication: 09.-2017, volume: 64, issue:9, pages: 2591 - 2597 Editeur: IEEE Document complet vers site de l'éditeur » A Combined Approach for Real-Time Data Compression in Wireless Body Sensor Networks  Résumé:Wireless body sensor networks (WBSNs) represent an enabling technology for unobtrusive patient monitoring. Unlike wireless sensor networks (WSNs), they are characterized by relatively few and heterogeneous sensors placed in, on, or around the human body. An important issue consists in designing efficient solutions for optimizing network resource usage, such as computational capacity, energy, and bandwidth. Compression algorithms for WBSNs need to satisfy more stringent requirements than solutions for typical WSNs. In particular, to guarantee real-time monitoring of vital signals, the algorithms cannot introduce latency. Furthermore, the maximum reconstruction error is usually very small and it needs to be known in advance. In this scenario, we propose a combined compression algorithm, which satisfied the previous requirements. Results obtained by considering different biomedical signals show that a significant compression ratio can be achieved also when very small values of the maximum error are considered. Auteurs: Giada Giorgi; Apparue dans: IEEE Sensors Journal Date publication: 09.-2017, volume: 17, issue:18, pages: 6129 - 6135 Editeur: IEEE Document complet vers site de l'éditeur » A Compact SISL Balun Using Compensated Interdigital Capacitor  Résumé:This letter proposes a compact self-packaged balun using compensated interdigital capacitor (CIDC) based on substrate integrated suspended line (SISL) platform. Compared with traditional single-layer interdigital capacitor or parallel-plate capacitor, CIDC has higher capacitance density and thus the circuit size can be reduced. Using the CIDC, a compact SISL balun based on a modified second-order lattice balun topology is designed and fabricated using the standard printed circuit board process. The measurement results agree well with the simulation ones, which shows that within 66.7% bandwidth, the measured amplitude imbalance and phase imbalance are ±0.89 dB and 181 ± 1.4°, respectively. A compact circuit size of$0.06~\lambda \text{g} \,\, \times 0.11~\lambda \text{g}$is achieved. Auteurs: Yongqiang Wang;Kaixue Ma;Shouxian Mou; Apparue dans: IEEE Microwave and Wireless Components Letters Date publication: 09.-2017, volume: 27, issue:9, pages: 797 - 799 Editeur: IEEE Document complet vers site de l'éditeur » A Compact-Area Low-VDDmin 6T SRAM With Improvement in Cell Stability, Read Speed, and Write Margin Using a Dual-Split-Control-Assist Scheme  Résumé:Previous 6T SRAMs commonly employ a wordline voltage underdrive (WLUD) scheme to suppress half-select (HS) disturbs in read and write cycles, at the expense of reduced cell read current ($I_{\mathrm {CELL}}$) and degraded write margin (WM). This paper proposes the dual-split-control (DSC) scheme, including split WLs and split cell VSS (CVSS), for 6T SRAM to maintain a compact cell area and improve HS cell stability during the read and write cycles without degrading$I_{\mathrm {CELL}}$and WM. A segmented CVSS-strapping scheme is developed to suppress the ground bounce on the split-CVSS lines. The CVSS voltage for S6T can be generated by either a constant voltage source or a charge-sharing-based CVSS generation scheme. A 28-nm 256-kb DSC6T SRAM macro was fabricated and achieves a 280-mV lower VDDmin than a conventional 6T SRAM. Auteurs: Meng-Fan Chang;Chien-Fu Chen;Ting-Hao Chang;Chi-Chang Shuai;Yen-Yao Wang;Yi-Ju Chen;Hiroyuki Yamauchi; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2498 - 2514 Editeur: IEEE Document complet vers site de l'éditeur » A Comprehensive Comparison of Multiparty Secure Additions with Differential Privacy  Résumé:This paper considers the problem of secure data aggregation (mainly summation) in a distributed setting, while ensuring differential privacy of the result. We study secure multiparty addition protocols using well known security schemes: Shamir’s secret sharing, perturbation-based, and various encryptions. We supplement our study with our new enhanced encryption scheme EFT, which is efficient and fault tolerant.Differential privacy of the final result is achieved by either distributed Laplace or Geometric mechanism (respectively DLPA or DGPA), while approximated differential privacy is achieved by diluted mechanisms. Distributed random noise is generated collectively by all participants, which draw random variables from one of several distributions: Gamma, Gauss, Geometric, or their diluted versions. We introduce a new distributed privacy mechanism with noise drawn from the Laplace distribution, which achieves smaller redundant noise with efficiency. We compare complexity and security characteristics of the protocols with different differential privacy mechanisms and security schemes. More importantly, we implemented all protocols and present an experimental comparison on their performance and scalability in a real distributed environment. Based on the evaluations, we identify our security scheme and Laplace DLPA as the most efficient for secure distributed data aggregation with differential privacy. Auteurs: Slawomir Goryczka;Li Xiong; Apparue dans: IEEE Transactions on Dependable and Secure Computing Date publication: 09.-2017, volume: 14, issue:5, pages: 463 - 477 Editeur: IEEE Document complet vers site de l'éditeur » A Compressed Sensing Based Decomposition of Electrodermal Activity Signals  Résumé:The measurement and analysis of electrodermal activity (EDA) offers applications in diverse areas ranging from market research to seizure detection and to human stress analysis. Unfortunately, the analysis of EDA signals is made difficult by the superposition of numerous components that can obscure the signal information related to a user's response to a stimulus. We show how simple preprocessing followed by a novel compressed sensing based decomposition can mitigate the effects of the undesired noise components and help reveal the underlying physiological signal. The proposed framework allows for decomposition of EDA signals with provable bounds on the recovery of user responses. We test our procedure on both synthetic and real-world EDA signals from wearable sensors and demonstrate that our approach allows for more accurate recovery of user responses as compared with the existing techniques. Auteurs: Swayambhoo Jain;Urvashi Oswal;Kevin Shuai Xu;Brian Eriksson;Jarvis Haupt; Apparue dans: IEEE Transactions on Biomedical Engineering Date publication: 09.-2017, volume: 64, issue:9, pages: 2142 - 2151 Editeur: IEEE Document complet vers site de l'éditeur » A Compulsator Driven Reluctance Coilgun-Type Electromagnetic Launcher  Résumé:Reluctance coilgun (RCG) is a special coilgun which uses solid ferromagnetic material instead of induction coil as projectile. RCG has shown great advantages and potential in the application of antiterrorism weaponry due to its simplicity, reliability, and excellent controllability. As a compact lightweight pulsed-power supply (PPS), the compensated pulsed alternator (Compulsator) will play a key role in promoting this kind of electromagnetic weapon into practical applications. Focused on a specific RCG which has conductive rails and brushes, this paper deduced the electromagnetic force analytical formula by using the virtual displacement principle and researched the feasibility of the electromagnetic launch design scheme which uses compulsator as the PPS of the RCG system by co-simulation method. Finally, this paper finished tests of the system by taking advantages of a small demonstrative RCG and a scale-model prototype of the compulsator. The results indicate that the design scheme is completely feasible. Auteurs: Bofeng Zhu;Junyong Lu;Jie Wang;Shicheng Xiong; Apparue dans: IEEE Transactions on Plasma Science Date publication: 09.-2017, volume: 45, issue:9, pages: 2511 - 2518 Editeur: IEEE Document complet vers site de l'éditeur » A Control Method for Bridgeless Cuk/Sepic PFC Rectifier to Achieve Power Decoupling  Résumé:Bulky electrolytic capacitor is usually needed in bridgeless power factor correction rectifiers to buffer the double-frequency ripple power (DFRP). However, it reduces the system reliability and power density significantly. This letter proposed a control method to divert DFRP to the small energy transfer capacitor. Then, the bulky electrolytic capacitor can be replaced with a small film capacitor. The proposed method is realized by making the best of the existing switching states. Therefore, it needs no extra switches or energy storage components, which are usually required in other active power decoupling methods. The operating principle is explained, and a closed-loop control strategy is proposed. Finally, the effectiveness is verified by experimental results. Auteurs: Yonglu Liu;Yao Sun;Mei Su; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 09.-2017, volume: 64, issue:9, pages: 7272 - 7276 Editeur: IEEE Document complet vers site de l'éditeur » A Convex Combination of NLMS and ZA-NLMS for Identifying Systems With Variable Sparsity  Résumé:This brief aims to identify and track a sparse system with time varying sparseness by a convex combination of two adaptive filters, one based on the sparsity unaware normalized least mean square (NLMS) algorithm and the other based on the sparsity aware zero-attracting NLMS (ZA-NLMS) algorithm. An analysis of the proposed combination is carried out, which reveals that while the proposed combination converges to the ZA-NLMS or the NLMS-based filter for systems that are highly sparse or highly non-sparse, respectively (i.e., better of the two under the given sparsity condition), it may, however, lead to a filter that performs better than both the constituent filters in the case of systems that lie between moderately sparse to moderately non-sparse. The same is confirmed via detailed simulation studies under different sparsity conditions. Auteurs: Bijit K. Das;G. Vinay Chakravarthi;Mrityunjoy Chakraborty; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1112 - 1116 Editeur: IEEE Document complet vers site de l'éditeur » A Convex Primal Formulation for Convex Hull Pricing  Résumé:In certain electricity markets, because of nonconvexities that arise from their operating characteristics, generators that follow the independent system operator's (ISO's) decisions may fail to recover their cost through sales of energy at locational marginal prices. The ISO makes discriminatory side payments to incentivize the compliance of generators. Convex hull pricing is a uniform pricing scheme that minimizes these side payments. The Lagrangian dual problem of the unit commitment problem has been solved in the dual space to determine convex hull prices. However, this approach is computationally expensive. We propose a polynomially solvable primal formulation for the Lagrangian dual problem. This formulation explicitly describes for each generating unit the convex hull of its feasible set and the convex envelope of its cost function. We cast our formulation as a second-order cone program when the cost functions are quadratic, and a linear program when the cost functions are piecewise linear. A 96-period 76-unit transmission-constrained example is solved in less than 15 s on a personal computer. Auteurs: Bowen Hua;Ross Baldick; Apparue dans: IEEE Transactions on Power Systems Date publication: 09.-2017, volume: 32, issue:5, pages: 3814 - 3823 Editeur: IEEE Document complet vers site de l'éditeur » A Copula-Based Trend-Renewal Process Model for Analysis of Repairable Systems With Multitype Failures  Résumé:Reliability analysis of multicomponent repairable systems with dependent component failures is challenging for two reasons. First, the failure mechanism of one component may depend on other components when considering component failure dependence. Second, imperfect repair actions can have accumulated effects on the repaired components and these accumulated effects are difficult to measure. In this paper, we propose a parametric statistical model to capture the failure dependence information with general component repair actions. We apply the maximum likelihood method to estimate the model parameters by utilizing the historical failure data. Statistical hypothesis tests are developed to determine the dependence structure of the component failures based on the proposed reliability model. The proposed methodology is demonstrated by a simulation study and case studies of a car body assembly process and a forklift vehicle system. Auteurs: Qingyu Yang;Yili Hong;Nailong Zhang;Jie Li; Apparue dans: IEEE Transactions on Reliability Date publication: 09.-2017, volume: 66, issue:3, pages: 590 - 602 Editeur: IEEE Document complet vers site de l'éditeur » A Data-Driven and Optimal Bus Scheduling Model With Time-Dependent Traffic and Demand  Résumé:Urban bus companies have collected a tremendous amount of travel data from passengers in the past years. In spite of great value for bus schedule optimization, these data have not been fully exploited. In this paper, we leverage hundreds of millions of bus transaction records, generated when passengers board and alight, to infer time-dependent traffic and customer demand. When the traffic and demand information are available, we build an optimal model to schedule the departure time of each bus service with the objective of minimizing the average waiting time. Experimental results show that compared with the existing bus scheduling system, our model can help reduce the waiting time by a wide margin. Auteurs: Yuan Wang;Dongxiang Zhang;Lu Hu;Yang Yang;Loo Hay Lee; Apparue dans: IEEE Transactions on Intelligent Transportation Systems Date publication: 09.-2017, volume: 18, issue:9, pages: 2443 - 2452 Editeur: IEEE Document complet vers site de l'éditeur » A Dataset and Benchmarks for Segmentation and Recognition of Gestures in Robotic Surgery  Résumé:Objective: State-of-the-art techniques for surgical data analysis report promising results for automated skill assessment and action recognition. The contributions of many of these techniques, however, are limited to study-specific data and validation metrics, making assessment of progress across the field extremely challenging. Methods: In this paper, we address two major problems for surgical data analysis: First, lack of uniform-shared datasets and benchmarks, and second, lack of consistent validation processes. We address the former by presenting the JHU-ISI Gesture and Skill Assessment Working Set (JIGSAWS), a public dataset that we have created to support comparative research benchmarking. JIGSAWS contains synchronized video and kinematic data from multiple performances of robotic surgical tasks by operators of varying skill. We address the latter by presenting a well-documented evaluation methodology and reporting results for six techniques for automated segmentation and classification of time-series data on JIGSAWS. These techniques comprise four temporal approaches for joint segmentation and classification: hidden Markov model, sparse hidden Markov model (HMM), Markov semi-Markov conditional random field, and skip-chain conditional random field; and two feature-based ones that aim to classify fixed segments: bag of spatiotemporal features and linear dynamical systems. Results: Most methods recognize gesture activities with approximately 80% overall accuracy under both leave-one-super-trial-out and leave-one-user-out cross-validation settings. Conclusion: Current methods show promising results on this shared dataset, but room for significant progress remains, particularly for consistent prediction of gesture activities across different surgeons. Significance: The results reported in this paper provide the first systematic and uniform evaluatio- of surgical activity recognition techniques on the benchmark database. Auteurs: Narges Ahmidi;Lingling Tao;Shahin Sefati;Yixin Gao;Colin Lea;Benjamín Béjar Haro;Luca Zappella;Sanjeev Khudanpur;René Vidal;Gregory D. Hager; Apparue dans: IEEE Transactions on Biomedical Engineering Date publication: 09.-2017, volume: 64, issue:9, pages: 2025 - 2041 Editeur: IEEE Document complet vers site de l'éditeur » A Decentralized Power Management Strategy for Hybrid Energy Storage System With Autonomous Bus Voltage Restoration and State-of-Charge Recovery  Résumé:For hybrid energy storage system in dc microgrid, effective power split, bus voltage deviation, and state-of-charge (SoC) violation are significant issues. Conventionally, they are achieved by centralized control or hierarchical control methods with communications. This paper proposes a simple and effective strategy to solve the problem in a decentralized manner. A high-pass filter-based droop (HPFD) controller is proposed to regulate the battery converter, and a virtual capacitance droop (VCD) controller is implemented for a supercapacitor (SC) converter. The cooperation of HPFD and VCD first achieves autonomous power split that high-frequency fluctuation is buffered by SC and low-frequency power is supplied by battery. Meanwhile, the bus voltage deviation induced by the droop-based power sharing is eliminated automatically at steady state. The resulted bus voltage restoration simultaneously enforces SC SoC back to its nominal value, and, thus, ensures continuous operation of SC as a power buffer without the violation of its SoC boundary. A design guideline is developed to ensure expected system dynamics. The effectiveness of the proposed method and analytical results are validated by simulations and experiments. Auteurs: Qianwen Xu;Jianfang Xiao;Xiaolei Hu;Peng Wang;Meng Yeong Lee; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 09.-2017, volume: 64, issue:9, pages: 7098 - 7108 Editeur: IEEE Document complet vers site de l'éditeur » A Descriptive Survey of Technical Editors  Résumé:Research problem: The purpose of the study was to fill gaps in our knowledge about technical editors' work practices and perceptions, knowledge that might be useful for teachers and practitioners, as well as current and prospective students. Research questions: (1) What work activities do technical editors engage in? (2) How do people become and progress in careers as technical editors? (3) What do technical editors perceive about the complexity of their work and its value to themselves and others? Literature review: The literature review focuses on previous surveys of technical editors, which have tended to focus on technology-related issues and been largely limited to samples obtained from the Society for Technical Communication.Methodology: A link to an online survey was sent to 32 professional organizations for technical and other professional, nonliterary, and nonjournalism editors. The leadership of each organization was asked to forward the link to its members; 12 complied, with a resulting 253 respondents. Responses to closed-ended questions were tabulated, while responses to the open-ended questions were analyzed thematically.Results and conclusions:The results revealed a broad range of job titles, disciplinary and professional fields, genres and media, editing-related tasks, and extent and type of collaboration. Respondents perceived as useful several forms of academic preparation, personality traits, and attitudes. About half the respondents had become editors through deliberate preparation during college (direct route) and half had not (indirect route). Thus, one implication of the results is that college students majoring in the sciences and other technical fields (indirect route) might be attracted to complementary minors and certificate programs in technical communication/editing. The sample was obtained from among a broader range of technical editors than samples used in previous surveys but was relatively small and, therefore, nongener- lizable. Future surveys should strive for a larger sample size and include questions about a wide range of demographic variables that can be correlated with the independent variables. Auteurs: Melinda L. Kreth;Elizabeth Bowen; Apparue dans: IEEE Transactions on Professional Communication Date publication: 09.-2017, volume: 60, issue:3, pages: 238 - 255 Editeur: IEEE Document complet vers site de l'éditeur » A Distributed Deployment Algorithm of Process Fragments With Uncertain Traffic Matrix  Résumé:Modern Internet of Things (IoT)-aware business processes include various geographically dispersed sensor devices. Large amounts of raw data acquired from sensors need to be regularly transmitted to the targeted processes in enterprise data centers, resulting in a significant increase in network load and latency. It is necessary to execute such processes in a distributed way. The existing work has proposed different algorithms to partition a given process for distributed execution; however, they cannot satisfy the decentralized nature of IoT-aware business processes. Moreover, up to now, there is few work that studies uncertain optimal deployment problems in which traffic data for guiding subsequent deployment derives from experts’ empirical knowledge. This paper proposes a novel location-based fragmentation algorithm and${\alpha }$-optimal deployment solution to deal with the mentioned problems, where${\alpha }$is the given confidence level. A hardware-in-the-loop simulation platform based on NS-3 was built. Based on this platform, an integrated monitoring process was deployed that ran on different virtual computers, and process fragments communicated with each other via a simulated network. The experimental results show that the proposed approach can reduce network traffic and round-trip time. Auteurs: Shoulu Hou;Shuai Zhao;Bo Cheng;Shiping Chen;Yongyang Cheng;Junliang Chen; Apparue dans: IEEE Transactions on Network and Service Management Date publication: 09.-2017, volume: 14, issue:3, pages: 690 - 701 Editeur: IEEE Document complet vers site de l'éditeur » A Dual-Imaging Speed-Enhanced CMOS Image Sensor for Real-Time Edge Image Extraction  Résumé:This paper presents a CMOS image sensor (CIS) that extracts a multi-level edge image as well as a human-friendly normal image in a real time from conventional pixels for machine-vision applications, utilizing a proposed speed/power-efficient dual-mode successive-approximation register analog-to-digital converter (SAR ADC). The proposed readout scheme operates in two modes, fine step SAR (FS-SAR) mode and coarse-step single-slope (CS-SS) mode, depending on the difference ($\Delta $) between a chosen pixel and the previous pixel. If a chosen pixel is at a boundary of an object with a large$\Delta $from the previous pixel, the readout ADC works in the CS-SS mode to readout the edge strength (ES), while the FS-SAR mode is applied for other pixels. By displaying the ES, a multi-level edge image can be obtained in a real time along with a normal image with no hardware/time overhead. By saving the MSBs conversion cycles regardless of$\Delta $, the proposed dual-mode readout scheme enhances the readout speed and reduces power consumption. A prototype QQVGA CIS with 10-bit SAR ADCs was fabricated in a 0.18-$\mu \text{m}$1P4M CMOS image sensor process with a 4.9-$\mu \text{m}$pixel pitch. With a maximum pixel rate of 61.4 Mp/s, the prototype demonstrated figure of merits of 70 pJ/pixel/frame, 0.35$\text{e}^{-}\cdot \text {nJ}$, and 0.34$\text{e}^{-}\cdot \text {pJ}$/step. Auteurs: Hyeon-June Kim;Sun-Il Hwang;Jae-Hyun Chung;Jong-Ho Park;Seung-Tak Ryu; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2488 - 2497 Editeur: IEEE Document complet vers site de l'éditeur » A Dual-Mode Magnetic–Acoustic System for Monitoring Fluid Intake Behavior in Animals  Résumé:We have developed an unobtrusive magnetic–acoustic fluid intake monitoring (MAFIM) system using a conventional stainless-steel roller-ball nipple to measure licking and drinking behavior in animals. Movements of a small permanent magnetic tracer attached to stainless-steel roller balls that operate as a tongue-actuated valve are sensed by a pair of three-axial magnetometers, and transformed into a time-series indicating the status of the ball (up or down), using a Gaussian mixture model based data-driven classifier. The sounds produced by the rise and fall of the roller balls are also recorded and classified to substantiate the magnetic data by an independent modality for a more robust solution. The operation of the magnetic and acoustic sensors is controlled by an embedded system, communicating via Universal Serial Bus (USB) with a custom-designed user interface, running on a PC. The MAFIM system has been tested in vivo with minipigs, accurately measuring various drinking parameters and licking patterns without constraints imposed by current lick monitoring systems, such as nipple access, animal-nipple contact, animal training, and complex parameter settings. Auteurs: Saman Sargolzaei;Hassan Elahi;Alan Sokoloff;Maysam Ghovanloo; Apparue dans: IEEE Transactions on Biomedical Engineering Date publication: 09.-2017, volume: 64, issue:9, pages: 2090 - 2097 Editeur: IEEE Document complet vers site de l'éditeur » A Dual-Polarized 1-D Tightly Coupled Dipole Array Antenna  Résumé:A dual-polarized 1-D tightly coupled dipole array (TCDA) antenna is proposed in this paper. To apply the TCDA design concept to a 1-D array, we place a conducting wall with slits and ferrite sheets along the 1-D dipole array. The simulated dual-polarized 1-D infinite TCDA antenna has a wide overlapped bandwidth of 2.83:1 (from 1 to 2.83 GHz) with VSWR < 2, high isolation (>25 dB) between the horizontal and vertical polarizations (VPs), and low height of$1/5~\lambda $at the lowest operating frequency. A prototype of the proposed array is fabricated and measured, which consists of nine horizontal polarization (HP) dipoles and eight VP dipoles interleaved between the HP dipoles. The measured results show high gains >7.2 dB when scanning up to 30° and a wide half-power beamwidth in the$yz$plane >61° over the operating frequency band for both polarizations, consistent with the simulation result. Auteurs: Hakjune Lee;Sangwook Nam; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4511 - 4518 Editeur: IEEE Document complet vers site de l'éditeur » A Fast and Low-Complexity Operator for the Computation of the Arctangent of a Complex Number  Résumé:The computation of the arctangent of a complex number, i.e., the atan2 function, is frequently needed in hardware systems that could profit from an optimized operator. In this brief, we present a novel method to compute the atan2 function and a hardware architecture for its implementation. The method is based on a first stage that performs a coarse approximation of the atan2 function and a second stage that improves the output accuracy by means of a lookup table. We present results for fixed-point implementations in a field-programmable gate array device, all of them guaranteeing last-bit accuracy, which provide an advantage in latency, speed, and use of resources, when compared with well-established fixed-point options. Auteurs: Vicente Torres;Javier Valls; Apparue dans: IEEE Transactions on Very Large Scale Integration Systems Date publication: 09.-2017, volume: 25, issue:9, pages: 2663 - 2667 Editeur: IEEE Document complet vers site de l'éditeur » A Fast Marching-on-in-Degree Solution for Analysis of Conductors Coated With Thin Dispersive Dielectric  Résumé:In this paper, a novel marching-on-in-degree-based time-domain electric field integral equation (TD-EFIE) is proposed for the analysis of conductors coated with thin dispersive dielectric. The algorithm begins with representing the polarization electric current/charge of the dielectric part in terms of the surface electric current of the conductor. Then, the TD-EFIE can only be formulated with the surface electric current by using the thin dielectric sheet approach. Since the spatial unknowns are only assigned to the surface of the conductor, the computational resources can be saved significantly. Besides, the analytical solution can be obtained for the convolution of the medium susceptibility and the divergence of surface electric current. Moreover, the time variables can be eliminated by using the Galerkin testing with the weighted Laguerre polynomials. As a result, the late time stability can be guaranteed. Numerical examples of Debye, Lorentz, and Drude media are given to demonstrate the validity of the proposed algorithm. Auteurs: Z. He;R. S. Chen; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4751 - 4758 Editeur: IEEE Document complet vers site de l'éditeur » A Fixed-Beam Leaky-Wave Cavity-Backed Slot Antenna Manufactured by Bulk Silicon MEMS Technology  Résumé:A fixed-beam leaky-wave slot antenna with an air-filled back cavity is proposed in the millimeter-waveband. The antenna is fabricated based on the bulk silicon microelectromechanical systems micromachining technology. This micromachining process can etch silicon wafers and plate them with gold. Because all surfaces of the proposed antenna are plated with gold, electromagnetic waves can transmit in the air medium without any other dielectric. The air-filled structure contributes to achieving a leaky-wave slot antenna with fixed beam as operating frequency varies. A prototype of the proposed antenna is fabricated to verify the design strategy. The measured results show that the impedance bandwidth of the proposed antenna is 55–67 GHz and within the operating frequency band, the main beam direction only varies from 48° to 53°, which confirms the fixed-beam characteristic. The measured peak gain varies from 9.1 to 10.5 dBi in the operating frequency band. Auteurs: Peiqin Liu;Yue Li;Zhijun Zhang;Shaodong Wang;Zhenghe Feng; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4399 - 4405 Editeur: IEEE Document complet vers site de l'éditeur » A Flash-Based Non-Uniform Sampling ADC With Hybrid Quantization Enabling Digital Anti-Aliasing Filter  Résumé:This paper introduces different classes of analog-to-digital converter (ADC) architecture that non-uniformly samples the analog input and shifts from conventional voltage quantization to a hybrid quantization paradigm wherein both voltage and time quantization are utilized. In this architecture, the sampling rate adapts to the input frequency, which maintains an alias-free spectrum and enables an anti-aliasing (AA) filtering in the digital domain to relax the analog AA filter. In addition, the digital AA filter can generate uniform outputs from non-uniform samples to interact with the synchronous digital signal processor seamlessly and benefit from reconfigurability and technology scaling. To prove the concept, a flash-based non-uniform sampling ADC is proposed and the circuit non-idealities of key building blocks are analyzed. A silicon prototype is implemented in a 65-nm CMOS, which utilizes a 15-level voltage quantizer and a shared time quantizer with maximum resolution of 9 ps. Combined with the digital AA filter, it improves SNR by 30 dB in comparison with a conventional 4-bit uniformly sampled Nyquist-rate ADC and measures an EVM of −28 dB for a 64 quadrature amplitude modulation input signal under a 30-dB higher blocker. Auteurs: Tzu-Fan Wu;Cheng-Ru Ho;Mike Shuo-Wei Chen; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2335 - 2349 Editeur: IEEE Document complet vers site de l'éditeur » A Flexible CO-OFDM Using Reconfigurable Multi-Precision FFT  Résumé:To improve flexibility, energy efficiency, and speed of elastic optical orthogonal frequency division multiplexing systems, a reconfigurable multi-precision fast Fourier transform (FFT) is presented. The minimum required FFT word length for different criteria—namely, the bit error rate (BER), FFT size, modulation format, and optical signal-to-noise ratio—is determined using simulations. At run time, system performance is improved significantly by using a reconfigurable multi-precision FFT, while the target BER is satisfied. The proposed design is synthesized on an FPGA, and the results show that both energy efficiency and processing speed are improved about 79% and 78%, respectively, compared with the conventional design. Auteurs: Hatam Abdoli;Hooman Nikmehr; Apparue dans: IEEE Communications Letters Date publication: 09.-2017, volume: 21, issue:9, pages: 1997 - 2000 Editeur: IEEE Document complet vers site de l'éditeur » A Fully Integrated Battery-Powered System-on-Chip in 40-nm CMOS for Closed-Loop Control of Insect-Scale Pico-Aerial Vehicle  Résumé:We demonstrate a fully integrated system-on-chip (SoC) optimized for insect-scale flapping-wing pico-aerial vehicles. The SoC is able to meet the stringent weight, power, and real-time performance demands of autonomous flight for a bee-sized robot. The entire integrated system with embedded voltage regulation, data conversion, clock generation, as well as both general-purpose and accelerated computing units, weighs less than 3 mg after die thinning. It is self-contained and can be powered directly off of a lithium battery. Measured results show open-loop wing flapping controlled by the SoC and improved energy efficiency through the use of hardware acceleration and supply resilience through the use of adaptive clocking. Auteurs: Xuan Zhang;Mario Lok;Tao Tong;Sae Kyu Lee;Brandon Reagen;Simon Chaput;Pierre-Emile J. Duhamel;Robert J. Wood;David Brooks;Gu-Yeon Wei; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2374 - 2387 Editeur: IEEE Document complet vers site de l'éditeur » A Fully Integrated Dual-Mode CMOS Power Amplifier With an Autotransformer-Based Parallel Combining Transformer  Résumé:This letter presents a fully integrated dual-mode power amplifier (PA) with an autotransformer-based parallel combining transformer (ABPCT), fabricated with a standard 40-nm CMOS process. In comparison with a parallel combining transformer, the proposed ABPCT can offer high-efficiency performance in both high-power (HP) and low-power (LP) modes, and does so with a compact die area. With an 802.11g signal (64-QAM 54 Mbps) of 20-MHz channel bandwidth, the fully integrated dual-mode PA achieves 19.7 and 15.7 dBm average output powers with PAEs of 17.1% and 13%, in HP and LP modes, respectively, while satisfying a −25 dB error vector magnitude and spectral mask requirements. Operating the PA in the LP mode can save more than 40% of the current consumption at a 10-dBm average output power when compared with that in the HP mode. Auteurs: Hyunjin Ahn;Seungjun Baek;Ilku Nam;Deokgi An;Jae Kyung Lee;Minsu Jeong;Bo-Eun Kim;Jaehyouk Choi;Ockgoo Lee; Apparue dans: IEEE Microwave and Wireless Components Letters Date publication: 09.-2017, volume: 27, issue:9, pages: 833 - 835 Editeur: IEEE Document complet vers site de l'éditeur » A Fuzzy Error Characterization Approach for Crack Depth Profile Estimation in Metallic Structures Through ACFM Data  Résumé:The estimation of fatigue crack depth profile is one of the most important issues in nondestructive evaluation techniques. In this regard, providing a method which is able to determine the error rate of the depth profile estimation will be significant. Although several methods have been proposed to estimate the depth profile with reasonable accuracy, these mentioned methods are unable to determine the error rate of estimation process. In this paper, to eliminate mentioned drawbacks, a first and second fuzzy approximation methodology is proposed to estimate the surface crack depth profile of an arbitrary crack in metallic structures based on alternating current field measurement signals. In the proposed method, it is feasible to achieve a definite error rate to determine the surface crack depth profile under evaluation. Next, to achieve the most reasonable accuracy and the least computational complexity simultaneously, a solution will be proposed for the method presented in this paper. Finally, the results of several common methods are compared with the method presented in this paper in analytical and experimental forms. Auteurs: Danial Katoozian;Reza P. R. Hasanzadeh; Apparue dans: IEEE Transactions on Magnetics Date publication: 09.-2017, volume: 53, issue:9, pages: 1 - 10 Editeur: IEEE Document complet vers site de l'éditeur » A Game Theoretic Approach to Network Reliability Assessment  Résumé:This paper evaluates the network reliability from a game theory perspective. We formulate a network game consisting of two players—router and attacker, where the router seeks to minimize his total expected trip cost, while the attacker attempts to maximize the expected trip cost by undermining some of the network links. Each link has a probabilistic cost in accordance with its state (normal or damaged). Two different scenarios are considered: link cost independent of the flow and link cost dependent on the flow. We are interested in the link use and damage probabilities at system equilibrium for both cases, and these probabilities are derived in a four-step procedure. First, for the router, Dijkstra and the Frank–Wolfe (FW) algorithms are used to optimize his strategy under the two scenarios, respectively. Second, we model the attacker's problem as a constrained optimization problem, in which all the decision variables are binary. A probabilistic solution discovery algorithm (PSDA) is integrated with stochastic ranking to determine the attacker's optimal strategy. Third, we leverage the Method of Successive Averages (MSA) to approximate the router's link use probabilities and attacker's link damage probabilities at the mixed Nash equilibrium of the game. Finally, given the router's probability of traveling through each link and attacker's probability of undermining each link, we use Monte Carlo Simulations (MCS) to estimate the network reliability as the router arriving the destination node within a prescribed time. Two numerical examples are used to illustrate the procedures and effectiveness of the proposed method. Auteurs: Xiaoge Zhang;Sankaran Mahadevan; Apparue dans: IEEE Transactions on Reliability Date publication: 09.-2017, volume: 66, issue:3, pages: 875 - 892 Editeur: IEEE Document complet vers site de l'éditeur » A Gap Waveguide-Fed Wideband Patch Antenna Array for 60-GHz Applications  Résumé:This communication presents a wideband aperture-coupled patch antenna array based on ridge gap waveguide feed layer for 60-GHz applications. The novelty of this antenna lies in the combination of relatively new gap waveguide technology along with conventional patch antenna arrays allowing to achieve a wideband patch antenna array with high gain and high radiation efficiency. An$8 \times 8$-element array antenna is designed, fabricated, and tested. Experimental results show that the bandwidth of VSWR < 2 is up to 15.5% (57.5–67.2 GHz). More than 75% efficiency and higher than 21.5-dBi gain are achieved over the operational bandwidth. The results are valuable for the design and evaluation of wideband planar antenna arrays at millimeter-wave frequencies. Auteurs: Davoud Zarifi;Ali Farahbakhsh;Ashraf Uz Zaman; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4875 - 4879 Editeur: IEEE Document complet vers site de l'éditeur » A GBSAR Operating in Monostatic and Bistatic Modalities for Retrieving the Displacement Vector  Résumé:Ground-based synthetic aperture radar (GBSAR) systems are popular remote sensing instruments for detecting ground changes of slopes, and small displacements of large structures as bridges, dams, and construction works. These radars are able to provide maps of displacement along range direction only. In this letter, we propose to use a transponder for operating a conventional linear GBSAR as a bistatic radar with the aim to acquire two different components of the displacement of the targets in the field of view. Auteurs: Massimiliano Pieraccini;Lapo Miccinesi;Neda Rojhani; Apparue dans: IEEE Geoscience and Remote Sensing Letters Date publication: 09.-2017, volume: 14, issue:9, pages: 1494 - 1498 Editeur: IEEE Document complet vers site de l'éditeur » A Gene–Protein–miRNA Electronic Oscillator  Résumé:This brief presents an electronic oscillator circuit model mimicking a unique relationship among six genes. Three out of the six genes are employed to synthesize proteins, while the remaining three are their complementary micro-ribonucleic acid (miRNA) genes degrading the messenger-RNA transcripts at the translational level of gene expression. The circuit runs without any external stimulus because the transcription of each gene is controlled by another gene in forming the oscillatory network. A feasibility procedure is also presented, which can be used to fabricate the proposed gene–protein–miRNA electronic oscillator in the biological domain. This research is valuable in designing complex synthetic gene regulatory networks and analyzing their biological behavior. Auteurs: Sadia Alam;S. M. Rezaul Hasan; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1007 - 1011 Editeur: IEEE Document complet vers site de l'éditeur » A General Dynamic Scaling Based Control Redesign to Handle Input Unmodeled Dynamics in Uncertain Nonlinear Systems  Résumé:A general class of uncertain nonlinear systems with dynamic input uncertainties (nonlinear input unmodeled dynamics) is considered. While the proposed approach can, in general, be applied to multi-input systems, single-input systems are considered here for simplicity. It is shown that if a nominal control law is available to globally asymptotically stabilize the nominal system (without the input unmodeled dynamics), then a dynamic scaling based redesign of the control law can be performed to achieve global asymptotic stabilization of the system with the input unmodeled dynamics. The proposed control redesign approach is applicable to a wide class of nonlinear systems including triangular and non-triangular structures as long as a set of structural and inequality conditions on the system dynamics is satisfied and yields a global robust output-feedback stabilizing controller. Auteurs: P. Krishnamurthy;F. Khorrami; Apparue dans: IEEE Transactions on Automatic Control Date publication: 09.-2017, volume: 62, issue:9, pages: 4719 - 4726 Editeur: IEEE Document complet vers site de l'éditeur » A General Expression to Determine the Rotor Field Current of Synchronous Machines  Résumé:This letter focuses on the dynamic modeling of synchronous machines and proposes a general exact equation to compute the field current of the rotor winding for transient stability analysis. The proposed approach is based on the semi-implicit formulation of differential-algebraic equations, which allows expressing the filed current in terms of the times derivatives of machine state variables, rather than in terms of the variables themselves. This leads to an expression which is compact, linear, and model independent and, thus, easily implementable in power system software tools. This letter illustrates the derivation of the equation leading to the field current for different machine models and shows, through a 21,177 bus model of the ENTSO-E transmission grid, how the derived equation reduces the computational burden of power system models. Auteurs: Federico Milano; Apparue dans: IEEE Transactions on Energy Conversion Date publication: 09.-2017, volume: 32, issue:3, pages: 1099 - 1101 Editeur: IEEE Document complet vers site de l'éditeur » A Genetic-Algorithm-Optimized Fractal Model to Predict the Constriction Resistance From Surface Roughness Measurements  Résumé:The electrical contact resistance greatly influences the thermal behavior of substation connectors and other electrical equipment. During the design stage of such electrical devices, it is essential to accurately predict the contact resistance to achieve an optimal thermal behavior, thus ensuring contact stability and extended service life. This paper develops a genetic algorithm (GA) approach to determine the optimal values of the parameters of a fractal model of rough surfaces to accurately predict the measured value of the surface roughness. This GA-optimized fractal model provides an accurate prediction of the contact resistance when the electrical and mechanical properties of the contacting materials, surface roughness, contact pressure, and apparent area of contact are known. Experimental results corroborate the usefulness and accuracy of the proposed approach. Although the proposed model has been validated for substation connectors, it can also be applied in the design stage of many other electrical equipments. Auteurs: Francesca Capelli;Jordi-Roger Riba;Elisa Rupérez;Josep Sanllehí; Apparue dans: IEEE Transactions on Instrumentation and Measurement Date publication: 09.-2017, volume: 66, issue:9, pages: 2437 - 2447 Editeur: IEEE Document complet vers site de l'éditeur » A Geometry-Based Channel Model to Simulate an Averaged-Power-Delay Profile  Résumé:Wireless communications or navigation is heavily influenced by electromagnetic wave propagation. The power-delay profile (PDP) characterizes the propagation channel by simple statistics. In this communication, we propose a channel model to simulate a given wideband averaged PDP obtained by measurements or theoretical considerations, enabling to test, develop, and design radio links. The channel model is based on a geometrical stochastic approach, allowing to simulate the space-variant channel impulse response for a moving receiver. Furthermore, the appearance and disappearance of multipath components are geometrically taken into account by an angular pattern. We verify the proposed methodology by simulations. Auteurs: Thomas Jost;Wei Wang;Michael Walter; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4925 - 4930 Editeur: IEEE Document complet vers site de l'éditeur » A GPU-Accelerated Fourth-Order Runge–Kutta in the Interaction Picture Method for the Simulation of Nonlinear Signal Propagation in Multimode Fibers  Résumé:The nonlinear signal propagation in fibers can be described by the nonlinear Schrödinger equation and the Manakov equation. Most commonly, split-step Fourier methods (SSFM) are applied to solve these nonlinear equations. The numerical simulation of the nonlinear signal propagation is especially challenging for multimode fibers, particularly if the calculation of very small step sizes or a large number of steps is required. Instead of utilizing SSFM, the fourth-order Runge-Kutta in the Interaction Picture (RK4IP) method can be applied. This method has the potential to reduce the numerical error while simultaneously allowing an increased step size. These advantages come at the price of a higher numerical effort compared to the SSFM method for the same step size. Since the simulation of the signal propagation in multimode fibers is already quite challenging, parallelization becomes an even more interesting option. We demonstrate the adaptation of the RK4IP method to simulate the nonlinear signal propagation in multimode fibers, including its parallelization. Besides comparing the performance of a parallelized implementation for multicore CPUs and a GPU-accelerated version, we discuss efficient strategies to implement the RK4IP method on a GPU accelerator with CUDA. In addition, the RK4IP implementation is numerically compared with a conventional SSFM implementation. Auteurs: Marius Brehler;Malte Schirwon;Dominik Göddeke;Peter M. Krummrich; Apparue dans: Journal of Lightwave Technology Date publication: 09.-2017, volume: 35, issue:17, pages: 3622 - 3628 Editeur: IEEE Document complet vers site de l'éditeur » A Handy Dandy Doherty PA: A Linear Doherty Power Amplifier for Mobile Handset Application  Résumé:As wireless communications progress from second to fourth-generation (4G) systems, the information content drastically increases, requiring high-data-rate transmissions. For efficient use of precious spectrum resources, the modulated signals have wider bandwidths (BWs) and higher peak-toaverage power ratios (PAPRs) than previous generations of systems. Therefore, the power amplifier (PA) operates at a less efficient backoff-power region to achieve the required linearity. Auteurs: Yunsung Cho;Daehyun Kang;Kyunghoon Moon;Daechul Jeong;Bumman Kim; Apparue dans: IEEE Microwave Magazine Date publication: 09.-2017, volume: 18, issue:6, pages: 110 - 124 Editeur: IEEE Document complet vers site de l'éditeur » A High Slew-Rate Adaptive Biasing Hybrid Envelope Tracking Supply Modulator for LTE Applications  Résumé:A linear-switch mode hybrid envelope tracking (ET) supply modulator utilizing adaptive biasing and gain enhanced current mirror operational transconductance amplifier (OTA) with class AB output stage in parallel with a switching regulator is presented. In comparison to a conventional OTA design with similar quiescent current consumption, proposed approach improves positive and negative slew rate from 50 to 93.4 V/$\mu \text{s}$and −87 to −152.5 V/$\mu \text{s}$, respectively, dc gain from 45 to 67 dB while consuming same amount of quiescent current. The proposed hybrid supply modulator achieves 83% peak efficiency, power-added efficiency (PAE) of 42.3% at 26.2 dBm for a 10-MHz 7.24-dB peak-to-average power ratio (PAPR) long-term evolution (LTE) signal and improves PAE by 8% at 6 dB back off from 26.2-dBm power amplifier (PA) output power with respect to fixed supply. With a 10-MHz 7.24-dB PAPR quadrature-phase shift keying LTE signal the ET PA system achieves adjacent channel leakage ratio (ACLR) of −37.7 dBc and error vector magnitude (EVM) of 4.5% at 26.2-dBm PA output power, while with a 10-MHz 8.15-dB PAPR 64QAM LTE signal the ET PA system achieves ACLR of −35.6 dBc and EVM of 6% at 26-dBm PA output power without digital predistortion. The proposed supply modulator core circuit occupies 1.1-mm2 die area, and is fabricated in a 0.18-$\mu \text{m}$CMOS technology. Auteurs: Yue Jing;Bertan Bakkaloglu; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3245 - 3256 Editeur: IEEE Document complet vers site de l'éditeur » A High-Consistency Broadband MEMS-Based Electrochemical Seismometer With Integrated Planar Microelectrodes  Résumé:This paper presents a broadband micro-electromechanical systems-based electrochemical seismometer with a new sensing unit composed of planar microelectrodes and perpendicular flow channels. The proposed sensing unit only needs three main microfabrication steps, leading to high consistency among devices which was quantified as 0.9978 ± 0.00050. Moreover, due to the new structure of the propose sensing unit, the raw device was featured with higher sensitivity [215.5 V/(m/s)], lower central working frequency (1 Hz), and wider working bandwidth (0.12–10.5 Hz) than previous reports. Based on the wide raw bandwidth, a broadband electrochemical seismometer was developed by the force balancing negative feedback with the final working bandwidth of 4.2 decades (0.0071–113 Hz). The linearity error and total harmonic distortion were both decreased by the feedback technology. In addition, the proposed devices demonstrated comparable self-noise level with the high-performance commercial counterpart “Trillium Compact.” Random seismic recording test was also conducted where the proposed device recorded a local earthquake with high consistency with the STS-2.5 deployed in the permanent station. Auteurs: Zhenyuan Sun;Guanglei Li;Lianhong Chen;Deyong Chen;Junbo Wang;Jian Chen; Apparue dans: IEEE Transactions on Electron Devices Date publication: 09.-2017, volume: 64, issue:9, pages: 3829 - 3835 Editeur: IEEE Document complet vers site de l'éditeur » A High-Sensitivity Fiber Bragg Grating Displacement Sensor Based on Transverse Property of a Tensioned Optical Fiber Configuration and Its Dynamic Performance Improvement  Résumé:This paper presents a high-sensitivity fiber Bragg grating (FBG) displacement sensor with a novel configuration for structural health monitoring. The transverse movement of an optical fiber that has been configured as a tight suspension status with its two ends fixed has been utilized to measure displacement. The theoretical models for both static and dynamic displacements have been derived. The corresponding simulations have been conducted to determine the relationship between the model parameters and the sensor performance. This approach supports the sensor design improvement and structural optimization. Two small working ranges have been selected to determine the simplified linear model according to Taylor series. The sensitivity of this sensor can reach up to 490.1 pm/mm with a high resolution of$2.04~\mu \text{m}$in a range of 1.4~2.0 mm. The introduction of the supporting spring unit has significantly enhanced the sensor’s resonant frequency without sacrificing the sensitivity. The application of the stiffer spring unit has enlarged the working bandwidth from 0~8 Hz to exceed 50 Hz. Enhancing the damping ratio unit can effectively improve the flatness of the dynamic response within the working bandwidth, while it does not affect other dynamic properties of the sensor. These improvements and design guidelines have been validated by both dynamic experiments and theoretical modeling. Auteurs: Tianliang Li;Yuegang Tan;Chaoyang Shi;Yongxing Guo;Zoran Najdovski;Hongliang Ren;Zude Zhou; Apparue dans: IEEE Sensors Journal Date publication: 09.-2017, volume: 17, issue:18, pages: 5840 - 5848 Editeur: IEEE Document complet vers site de l'éditeur » A High-Speed Efficient 220-GHz Spatial-Orthogonal ASK Transmitter in 130-nm SiGe BiCMOS  Résumé:Wireless communication using terahertz/sub-terahertz band can alleviate the spectrum scarcity in conventional RF ands and satisfy the drastically expanding demands for capacity. In this paper, a spatial-orthogonal ASK transmitter architecture is presented. The self-sustaining oscillator-based transmitter architecture has an ultra-compact size and excellent power efficiency. With the proposed high-speed constant-load switch, significantly reduced modulation loss is achieved. Using polarization diversity and multi-level modulation, the throughput is largely enhanced. Array configuration is also adopted to enhance the link budget for higher signal quality and longer communication range. Fabricated in a 130-nm SiGe BiCMOS technology, the transmitter achieves an EIRP of 21 dBm and dc-to-THz-radiation efficiency of 0.7% in each spatial channel. A 24.4-Gb/s total data rate over a 10-cm communication range is demonstrated. With an external Teflon lens system, the demonstrated communication range is further extended to 52 cm. Compared with prior art, the proposed transmitter shows much higher power efficiency. Auteurs: Chen Jiang;Andreia Cathelin;Ehsan Afshari; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2321 - 2334 Editeur: IEEE Document complet vers site de l'éditeur » A Humidity Sensor Based on a Singlemode-Side Polished Multimode–Singlemode Optical Fibre Structure Coated with Gelatin  Résumé:A novel relative humidity sensor based on a singlemode-side polished multimode-singlemode fibre structure coated with gelatin material is reported. The sensing principle and fabrication method of the proposed sensor are presented. The experimental method is demonstrated to provide the optimum thickness of coating layers in order to achieve the highest sensitivity of 0.14 dB/%RH and a fast response time of 1000 ms for a given relative humidity sensing range. The developed humidity fibre optic sensor based on a gelatin coating shows great potential for many applications such as industrial production, food processing, and environmental monitoring. Auteurs: Xianfan Wang;Gerald Farrell;Elfed Lewis;Ke Tian;Libo Yuan;Pengfei Wang; Apparue dans: Journal of Lightwave Technology Date publication: 09.-2017, volume: 35, issue:18, pages: 4087 - 4094 Editeur: IEEE Document complet vers site de l'éditeur » A Hybrid Approach for Near-Range Video Stabilization  Résumé:Near-range videos contain objects that are close to the camera. These videos often contain discontinuous depth variation (DDV), which is the main challenge to the existing video stabilization methods. Traditionally, 2D methods are robust to various camera motions (e.g., quick rotation and zooming) under scenes with continuous depth variation (CDV). However, in the presence of DDV, they often generate wobbled results due to the limited ability of their 2D motion models. Alternatively, 3D methods are more robust in handling near-range videos. We show that, by compensating rotational motions and ignoring translational motions, near-range videos can be successfully stabilized by 3D methods without sacrificing the stability too much. However, it is time-consuming to reconstruct the 3D structures for the entire video and sometimes even impossible due to rapid camera motions. In this paper, we combine the advantages of 2D and 3D methods, yielding a hybrid approach that is robust to various camera motions and can handle the near-range scenarios well. To this end, we automatically partition the input video into CDV and DDV segments. Then, the 2D and 3D approaches are adopted for CDV and DDV clips, respectively. Finally, these segments are stitched seamlessly via a constrained optimization. We validate our method on a large variety of consumer videos. Auteurs: Shuaicheng Liu;Binhan Xu;Chuang Deng;Shuyuan Zhu;Bing Zeng;Moncef Gabbouj; Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology Date publication: 09.-2017, volume: 27, issue:9, pages: 1922 - 1933 Editeur: IEEE Document complet vers site de l'éditeur » A Hybrid FETD-GSM Algorithm for Broadband Full-Wave Modeling of Resonant Waveguide Devices  Résumé:An efficient hybrid algorithm that combines the finite-element time-domain (FETD) method with the generalized scattering matrix (GSM) technique is proposed to characterize the properties of wave propagation in highly resonant waveguide devices. To alleviate the problem of an extremely large number of time steps required for a highly resonant device, the algorithm first divides the device into several less resonant or resonant-free subdomains to reduce the number of time steps and the computational complexity of the FETD solver. The subdomain interfaces, which are assumed to be homogeneous, are modeled with an accurate waveguide port boundary condition (WPBC) to absorb any impinging waveguide modes. Each subdomain is then represented by a broadband GSM, which is computed by the fast Fourier transform of the FETD solutions. Finally, the subdomain GSMs are cascaded to form the global GSM of the original resonant device. The formulation and implementation of the FETD method with the WPBC, its required general waveguide modal analysis, and the cascading of GSMs are discussed in detail. Three numerical examples are presented to demonstrate the accuracy and efficiency of the proposed hybrid algorithm. Auteurs: Kedi Zhang;Chao-Fu Wang;Jian-Ming Jin; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3147 - 3158 Editeur: IEEE Document complet vers site de l'éditeur » A Hybrid PWM-Based Field Weakening Strategy for a Hybrid-Inverter-Driven Open-Winding PMSM System  Résumé:This paper proposes a hybrid pulse width modulation (PWM) based field weakening control strategy for a hybrid-inverter-driven open-winding (OW) permanent magnet synchronous motor (PMSM) system. The hybrid-inverter consists of two voltage source inverters, one is connected to a dc voltage source and named as main inverter (MI), and the other is connected to a floating capacitor and called compensation inverter (CI). A novel hybrid PWM technique is proposed for the hybrid-inverter, in which a double-vector-based PWM is applied to the MI to reduce the switching frequency, and the conventional space vector PWM is applied to the CI to compensate the reactive power. Furthermore, a field weakening (FW) control strategy based on the hybrid PWM technique is proposed to better utilize the dc-link voltage and extend the operation range of the OW-PMSM system. Simulation and experimental studies are carried out to verify the high efficiency and wide speed range of the proposed strategy. Auteurs: Dan Sun;Zhihao Zheng;Bin Lin;Wenzhi Zhou;Min Chen; Apparue dans: IEEE Transactions on Energy Conversion Date publication: 09.-2017, volume: 32, issue:3, pages: 857 - 865 Editeur: IEEE Document complet vers site de l'éditeur » A Joint Optimization Approach for the Synthesis of Large 4-D Heterogeneous Antenna Arrays  Résumé:Due to the inherent nonlinearity in the synthesis of large four dimensional (4-D) heterogeneous arrays, conventional pattern synthesis techniques are no longer suitable. In this paper, an effective joint optimization approach based on the combination of convex programming (CP) and differential evolution (DE) algorithm is proposed. By designing suitable time sequences of a 4-D heterogeneous array with uniform static amplitude excitations, the original synthesis problem is simplified into two independent small problems, which can be easily solved in two steps, respectively. In the first step, the approach takes definite advantages from the convexity of the problem with respect to the static phase excitations and the switch-on duration times. These optimization variables become known and are fixed in the second step. Then, the DE algorithm is used to optimize the switch-on time instants. Owing to the efficiency of the CP, only 2/3 of the optimization variables need be solved in the first step, while even fewer number of optimization variables are solved in the second step. Consequently, the joint optimization of CP and DE algorithm significantly improves the overall synthesis efficiency. Two numerical examples are presented to demonstrate the effectiveness of the proposed approach. Auteurs: Feng Yang;Shiwen Yang;Yikai Chen;Shiwei Qu; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4585 - 4594 Editeur: IEEE Document complet vers site de l'éditeur » A language for the internet of underwater things [News]  Résumé:Aquatic robots are busier than ever. They have seabeds to mine, cable pathways to plough, and marine data to gather. But they and their aquatic brethren-including submarines and scuba divers-still struggle to communicate. For decades, global standards defining Wi-Fi and cellular networks have allowed people to exchange data over the air. But those technologies are worthless below the waves, and no such standards have existed for underwater communications. Aquatic systems have instead used a mishmash of acoustic and optical signals to send and receive messages. Auteurs: Amy Nordrum; Apparue dans: IEEE Spectrum Date publication: 09.-2017, volume: 54, issue:9, pages: 9 - 10 Editeur: IEEE Document complet vers site de l'éditeur » A Linearization Technique for Differential OTAs  Résumé:This brief presents an operational transconductance amplifier (OTA) linearization technique that is applied to a low-noise amplifier (LNA) and an OTA-C filter. Simulations show the effectiveness of the proposed technique on the LNA, whose noise and gain performance remain unaffected while the linearity is significantly improved. Measurements of the 80-MHz fourth order Butterworth OTA-C filter are also presented. It is implemented using six OTAs instead of eight, thus reducing the power consumption and area. The filter is implemented in 65-nm low-power CMOS, with a core area of 0.05 mm$^{\boldsymbol 2}$and consumes 12.6 mA from 1.2 V supply. The measured in-band noise voltage is below 42 nV/$\mathbf {\sqrt {Hz}}$, and the measured third order intercept point improvement using OTA linearization is up to 17 dB in-band and about 3 dB out-of-band. Supply and temperature variation measurements on three samples show that the linearization is effective without a need for bias adjustment. Auteurs: Mohammed Abdulaziz;Waqas Ahmad;Markus Törmänen;Henrik Sjöland; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1002 - 1006 Editeur: IEEE Document complet vers site de l'éditeur » A Low-Cost Approach to the Skin Effect Compensation in Cylindrical Shunts  Résumé:In this paper the development of a new design solution for high-current shunt resistors is presented, which allows achieving very good accuracy while requiring a simple and low-cost manufacturing process. It is based on a solid cylinder having the voltage measurement circuit which runs through two holes drilled in the cylinder itself. Starting from the well-known expression of the current density in a cylindrical conductor, the frequency response of the shunt is obtained in closed form as a function of the geometric parameters. In turn, the positions of the voltage measurement terminals are chosen by optimizing the frequency response function over a specified range. A shunt prototype has been manufactured and its measurement performance has been evaluated. The experimental results confirm the validity of the approach and highlight the significant improvement with respect to the single-hole cylindrical shunt which has been recently proposed by the authors. The obtained measurement accuracy is noticeable when compared with the ease of manufacturing. Auteurs: Marco Faifer;Roberto Ferrero;Christian Laurano;Roberto Ottoboni;Sergio Toscani;Michele Zanoni; Apparue dans: IEEE Transactions on Instrumentation and Measurement Date publication: 09.-2017, volume: 66, issue:9, pages: 2266 - 2273 Editeur: IEEE Document complet vers site de l'éditeur » A Low-Noise Charge Amplifier for the ELENA Trajectory, Orbit, and Intensity Measurement System  Résumé:A low-noise head amplifier has been developed for the extra low energy antiproton ring beam trajectory, orbit, and intensity measurement system at CERN. This system is based on 24 double-electrode electrostatic beam position monitors installed around the ring. A head amplifier is placed close to each beam position monitor to amplify the electrode signals and generate a difference and a sum signal. These signals are sent to the digital acquisition system, about 50 m away from the ring, where they are digitized and further processed. The beam position can be measured by dividing the difference signal by the sum signal while the sum signal gives information relative to the beam intensity. The head amplifier consists of two discrete charge preamplifiers with junction field effect transistor (JFET) inputs, a sum and a difference stage, and two cable drivers. Special attention has been paid to the amplifier printed circuit board design to minimize the parasitic capacitances and inductances at the charge amplifier stages to meet the gain and noise requirements. The measurements carried out on the head amplifier showed a gain of 40.5 and 46.5 dB for the sum and difference outputs with a bandwidth from 200 Hz to 75 MHz and an input voltage noise density lower than$400~\text {pV}/\surd \text{Hz}$. Twenty head amplifiers have been already installed in the ring and they have been used to detect the first beam signals during the first commissioning stage in November 2016. Auteurs: Ricardo Marco-Hernández;Marco Baú;Marco Ferrari;Vittorio Ferrari;Flemming Pedersen;Lars Søby; Apparue dans: IEEE Transactions on Nuclear Science Date publication: 09.-2017, volume: 64, issue:9, pages: 2465 - 2473 Editeur: IEEE Document complet vers site de l'éditeur » A Low-Power NB-IoT Transceiver With Digital-Polar Transmitter in 180-nm CMOS  Résumé:A fully integrated 750~960 MHz wireless transceiver (TRX) is presented for single-tone NB-IoT applications. Effective design methodologies and techniques, from the system level to circuit level, are proposed to address various design challenges while achieving low-power consumption. The TRX consists of a low-IF receiver with 180-kHz signal bandwidth, a digital polar transmitter with 3.75-kHz signal bandwidth, and a fractional-N frequency synthesizer. Passive current mixer is employed in the receiver to improve the linearity and avoid the sensitivity degradation due to 1/${f}$noise. Automatic I/Q imbalance calibration is integrated to improve image rejection ratio (IRR) with the aid of external FPGA. The transmitter is implemented in the digital polar architecture to improve the narrow-band spectrum purity, integrated with an inverse Class-D digital power amplifier (DPA) to achieve high output power and efficiency. A Class-C voltage-controlled oscillator with automatic frequency control assisted the dynamic gate biasing technique is used in the fractional-N PLL frequency synthesizer. Two prototypes are implemented in 180-nm CMOS. By optimizing analog baseband configuration in the receiver and utilizing the revised thermometer-coding and binary-coding-based array placement in the DPA, the receiver achieves 4.0-dB noise figure, 48-dB IRR, and 60-dB PGA dynamic range, and the DPA outputs 23.2dBm maximum saturation power with 44.5% PAE. Furthermore, the transmitter system verifications demonstrate 3.87% error-vector magnitude (EVM) for 891 MHz$\pi $/4-DQPSK signals at 18.87-dBm output power with −40-dBc out-of-band rejection. The transmitter achieves a dynamic range from −35 to 20 dBm when the demodulation EVM threshold of the sys- em is set to 10%. Auteurs: Zheng Song;Xiliang Liu;Xiaokun Zhao;Qiongbing Liu;Zongming Jin;Baoyong Chi; Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers Date publication: 09.-2017, volume: 64, issue:9, pages: 2569 - 2581 Editeur: IEEE Document complet vers site de l'éditeur » A Low-Power SiGe BiCMOS 190-GHz Transceiver Chipset With Demonstrated Data Rates up to 50 Gbit/s Using On-Chip Antennas  Résumé:This paper presents a 190-GHz direct conversion transceiver (TRX) chipset with on-chip antennas implemented in a 130-nm SiGe BiCMOS technology for short-distance high-data-rate wireless links. The transmitter (TX) consists of an active fundamental upconversion mixer, a local oscillator (LO) driver, and a passive balun for differential to single-ended conversion of the RF signal. The receiver (RX) is composed of a low-noise amplifier, an active fundamental mixer, an LO driver, a variable-gain baseband (BB) amplifier, and a totem-pole output stage. The wireless communication between TX and RX is enabled by on-chip monopole antennas, which are fabricated using standard wire-bonding tools. Measurements of the TRX chipset equipped with these antennas show a 6-dB BB link bandwidth of 20 GHz, corresponding to 40 GHz of the RF link bandwidth. In a data transmission test setup based on a BPSK modulation, data rates of up to 40 Gbit/s over 20 mm and up to 50 Gbit/s over 6 mm are demonstrated. Consuming only 122 mW in the RX and 32 mW in the TX, this leads to a very low required energy per transferred bit of 3.9 and 3.1 pJ for the 40- and 50-Gbit/s link, respectively. Auteurs: David Fritsche;Paul Stärke;Corrado Carta;Frank Ellinger; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3312 - 3323 Editeur: IEEE Document complet vers site de l'éditeur » A Mathematical Model of Non-Diffusion-Based Mobile Molecular Communication Networks  Résumé:This letter presents a mathematical model of molecular communication networks where mobile bio-nanomachines coordinate their motion by using non-diffusive surface-bound molecules for detecting and localizing spatially distributed targets in the environment. The mathematical model assumes that bio-nanomachines release two types of molecule: repellents to distribute bio-nanomachines in search of targets and attractants to attract distributed bio- nanomachines toward target locations. The two types of molecule assumed in this letter are non-diffusive, meaning that molecules bind to a surface in the environment, creating concentration gradients on the surface in order to distribute bio-nanomachines according to the target distribution. In this letter, we first develop dimensionless equations for the non-diffusion-based mobile molecular communication networks. We then perform mathematical analysis to show that, at steady-state, bio- nanomachines distribute according to a given target distribution. Finally, we demonstrate through numerical experiments that the bio-nanomachine distribution converges to the steady-state solution. Auteurs: Satoru Iwasaki;Jian Yang;Tadashi Nakano; Apparue dans: IEEE Communications Letters Date publication: 09.-2017, volume: 21, issue:9, pages: 1969 - 1972 Editeur: IEEE Document complet vers site de l'éditeur » A Method for Consistent Estimation of Multiple Land Surface Parameters From MODIS Top-of-Atmosphere Time Series Data  Résumé:Most methods for generating global land surface products from satellite data are parameter specific and do not use multiple temporal observations, which often results in spatial and temporal discontinuity and physical inconsistency among different products. This paper proposes a data assimilation (DA) scheme to simultaneously estimate five land surface parameters from Moderate Resolution Imaging Spectroradiometer (MODIS) top-of-atmosphere (TOA) time series reflectance data under clear and cloudy conditions. A coupled land surface–atmosphere radiative transfer model is developed to simulate TOA reflectance, and an ensemble Kalman filter technique is used to retrieve the most influential surface parameters of the coupled model, such as leaf area index, by combining predictions from dynamic models and the MODIS TOA reflectance data whether under clear or cloudy conditions. Then, the retrieved surface parameters are input to the coupled model to calculate four other parameters: 1) land surface reflectance; 2) incident photosynthetically active radiation (PAR); 3) land surface albedo; and 4) the fraction of absorbed PAR (FAPAR). The estimated parameters are compared with those of the corresponding MODIS, the Global LAnd Surface Satellite, and the Geoland2/BioPar version 1 (GEOV1) products. Validation of the estimated parameters against ground measurements from several sites with different vegetation types demonstrates that this method can estimate temporally complete land surface parameter profiles from MODIS TOA time series reflectance data, with accuracy comparable to that of existing satellite products over the selected sites. The retrieved leaf area index profiles are smoother than the existing satellite products, and unlike the MOD09GA product, the retrieved surface reflectance values do not have the high peak values influenced by clouds. The use of the coupled land surface–atmosphere model a- d the DA technique ensures physical connections between the land surface parameters and makes it possible to calculate radiation-related parameters for clear and cloudy atmospheric conditions, which is an improvement for FAPAR retrieval compared with the MODIS and GEOV1 products. The retrieved FAPAR and PAR values can reveal the significant differences in them under clear and cloudy atmospheric conditions. Auteurs: Hanyu Shi;Zhiqiang Xiao;Shunlin Liang;Han Ma; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 09.-2017, volume: 55, issue:9, pages: 5158 - 5173 Editeur: IEEE Document complet vers site de l'éditeur » A Millimeter-Wave Indoor Backscattering Channel Model for Environment Mapping  Résumé:In this communication, we introduce a channel model for personal radar applications where a millimeter-wave (mm-wave) massive array is required to scan the environment and to reconstruct a map of it. The analysis is based on measurement campaigns, in a corridor and in an office room, performed using mm-wave massive arrays. In such a context, we aim at characterizing the channel from both a temporal and an angular perspective by exploiting a 2D CLEAN-like technique to extrapolate the multipath components and a K-means algorithm for clustering, where centroids statistics depend on the environment contour. The obtained channel model can be exploited for mapping algorithms based on backscattered radar measurements. Auteurs: Anna Guerra;Francesco Guidi;Davide Dardari;Antonio Clemente;Raffaele D’Errico; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4935 - 4940 Editeur: IEEE Document complet vers site de l'éditeur » A Millimeter-Wave Klystron Upconverter With a Higher Order Mode Output Cavity  Résumé:Manufacturing of klystrons in the millimeter-wave frequency range is challenging due to the small size of the cavities and the ratio of the maximum gap voltage to the beam energy. The small dimensions also make difficult to produce devices with the output power required by a number of applications at millimeter wave, such as communications and spectroscopy. Operating with a higher order mode can be a potential solution, as a larger transverse size structure can be used. Unfortunately, high-order mode cavities have a lower impedance than in fundamental mode. In this paper is proposed a novel solution to overcome the reduced impedance by utilizing an upconverter, where all cavities except the output cavity are designed to work in high-order mode. To demonstrate the effectiveness of the approach, two klystron upconverters were designed. One has six cavities aiming to achieve a maximum output power of ~90 W at 105 GHz. The second klystron upconverter was a simpler three-cavity structure designed for quick prototype. Millimeter-wave measurements of the three-cavity klystron upconverter are presented. Auteurs: Graeme Burt;Liang Zhang;David A. Constable;Huabi Yin;Chris J. Lingwood;Wenlong He;Claudio Paoloni;Adrian W. Cross; Apparue dans: IEEE Transactions on Electron Devices Date publication: 09.-2017, volume: 64, issue:9, pages: 3857 - 3862 Editeur: IEEE Document complet vers site de l'éditeur » A Model-Based Strategy for Interturn Short-Circuit Fault Diagnosis in PMSM  Résumé:A model-based method for interturn short-circuit fault detection and isolation in permanent magnet synchronous machines (PMSMs) is proposed in this paper. The fault detection is realized based on a residual current vector (RCV) generated by the difference between the measured stator currents and the stator currents estimated by a state observer. In order to avoid false alarms due to possible undesired perturbations, the sequence decomposition of the RCV is performed by employing different reference-frames. Thus, the proposed RCV allows the correct detection of interturn short-circuit faults and quantification of the fault severity in any faulty stator-phase winding. Moreover, since the back-EMF generated by the magnets is proportional to the rotor shaft speed, the electrical angular speed is estimated through the stator voltages measurement, without using a speed sensor. Simulation results from the three-phase PMSM dynamic model that allows considering the interturn short-circuit fault in any stator phase-windings are presented. The proposed method is validated using a three-phase PMSM prototype with modified stator windings. The robustness and the reliability of the proposal was tested for several interturn fault conditions under transient conditions including different disturbances. Auteurs: Manuel A. Mazzoletti;Guillermo R. Bossio;Cristian H. De Angelo;Diego R. Espinoza-Trejo; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 09.-2017, volume: 64, issue:9, pages: 7218 - 7228 Editeur: IEEE Document complet vers site de l'éditeur » A Modified Plane Wave Model for Fast and Accurate Characterization of Layered Media  Résumé:The accuracy and computational speed of ground penetrating radar (GPR) largely rely on the inverse model implemented. In most cases, both accuracy and processing speed cannot be achieved together because of the inherent limitation of modeling GPR signal in complex media. Full wave models (FWMs) are most promising approaches to characterize multilayered media. However, they are inefficient due to the requirement of significant time for integration over singularity. In this paper, a modified plane wave model (MPWM) is proposed to achieve accuracy and better computational speed. The model is derived based on the analytical solution of an FWM. It is versatile for finding response due to multilayered media. The rigorous analysis has shown the similarity between the proposed model and FWMs with cross-correlation value close to unity across a broad frequency spectrum and large ranges of media parameters. Model inversion is achieved by a novel layer stripping technique followed by a gradient-based method. Testing of layered media in laboratory environment demonstrates that the proposed MPWM has significant advantage over FWMs. Auteurs: Subrata Maiti;Sarat Kumar Patra;Amitabha Bhattacharya; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3492 - 3502 Editeur: IEEE Document complet vers site de l'éditeur » A Modular Multilevel Generic Pulse-Waveform Generator for Pulsed Electric Field Applications  Résumé:High-voltage (HV) pulses are used in pulsed electric field (PEF) applications to provide an effective electroporation process, a process in which harmful microorganisms are disinfected when subjected to a PEF. Depending on the PEF application, different HV pulse specifications are required such as the pulse-waveform shape, the voltage magnitude, the pulse duration, and the pulse repetition rate. In this paper, a generic pulse-waveform generator (GPG) is proposed, and the GPG topology is based on half-bridge modular multilevel converter (HB-MMC) cells. The GPG topology is formed of four identical arms of series-connected HB-MMC cells forming an H-bridge. Unlike the conventional HB-MMC-based converters in HVdc transmission, the GPG load power flow is not continuous which leads to smaller size cell capacitors utilization; hence, smaller footprint of the GPG is achieved. The GPG topology flexibility allows the controller software to generate a basic multilevel waveform which can be manipulated to generate the commonly used PEF pulse waveforms. Therefore, the proposed topology offers modularity, redundancy, and scalability. The viability of the proposed GPG converter is validated by MATLAB/Simulink simulation and experimentation. Auteurs: Mohamed A. Elgenedy;Ahmed Darwish;Shehab Ahmed;Barry W. Williams; Apparue dans: IEEE Transactions on Plasma Science Date publication: 09.-2017, volume: 45, issue:9, pages: 2527 - 2535 Editeur: IEEE Document complet vers site de l'éditeur » A MPTCP-Based Network Architecture for Intelligent Train Control and Traffic Management Operations  Résumé:This paper investigates a novel communication system architecture for traffic management and data control in railway scenarios. The proposed solution should be integrated in the existing European Railway Traffic Management System/European Train Control System, the most advanced and successful standard even outside the European countries. Our system integrates public land mobile networks that usually offer best-effort packet services, with a quality-of-service (QoS) guaranteed satellite network. It represents a cost-effective substitution for 4G and 5G networks, aiming to replace current well-known GSM-R standard. The coexistence of heterogeneous networks is guaranteed by the multi-path transmission control protocol (TCP) protocol that addresses specific “add and drop” subflow policies and priority handling logics, in order to realize efficient seamless handovers. Providing priority to TCP subflows corresponds to select QoS-guaranteed, and the best effort networks able to fulfill railway requirements. The logic of adding and dropping subflows exploits both a real-time check of the current status of the serving network and “a priori” network performance information. Experimental results have been carried out in both city and harsh environments, where the main performance metrics (i.e., average delay, jitter, and bit rate) have been assessed. Auteurs: Yiwei Liu;Alessandro Neri;Agostino Ruggeri;Anna Maria Vegni; Apparue dans: IEEE Transactions on Intelligent Transportation Systems Date publication: 09.-2017, volume: 18, issue:9, pages: 2290 - 2302 Editeur: IEEE Document complet vers site de l'éditeur » A Multi-Agent Advanced Traveler Information System for Optimal Trip Planning in a Co-Modal Framework  Résumé:We present an advanced traveler information system (ATIS) for public and private transportation, including vehicle sharing and pooling services. The ATIS uses an agent-based architecture and multi-objective optimization to answer trip planning requests from multiple users in a co-modal setting, considering vehicle preferences and conflicting criteria. At each set of users’ requests, the transportation network is represented by a co-modal graph that allows decomposing the trip planning problem into smaller tasks: the shortest routes between the network nodes are determined and then combined to obtain possible itineraries. Using multi-objective optimization, the set of user-vehicle-route combinations according to the users’ preferences is determined, ranking all possible route agents’ coalitions. The ATIS is tested for the real case study of the Lille metropolitan area (Nord Pas de Calais, France). Auteurs: Mariagrazia Dotoli;Hayfa Zgaya;Carmine Russo;Slim Hammadi; Apparue dans: IEEE Transactions on Intelligent Transportation Systems Date publication: 09.-2017, volume: 18, issue:9, pages: 2397 - 2412 Editeur: IEEE Document complet vers site de l'éditeur » A Multi-Objective Optimization Approach for Question Routing in Community Question Answering Services  Résumé:Community Question Answering (CQA) has increasingly become an important service for people asking questions and providing answers online, which enables people to help each other by sharing knowledge. Recently, with accumulation of users and contents, much concern has arisen over the efficiency and answer quality of CQA services. To address this problem, question routing has been proposed which aims at routing new questions to suitable answerers, who have both high possibility and high ability to answer the questions. In this paper, we formulate question routing as a multi-objective ranking problem, and present a multi-objective learning-to-rank approach for question routing (MLQR), which can simultaneously optimize the answering possibility and answer quality of routed users. In MLQR, realizing that questions are relatively short and usually attached with tags, we first propose a tagword topic model (TTM) to derive topical representations of questions. Based on TTM, we then develop features for each question-user pair, which are captured at both platform level and thread level. In particular, the platform-level features summarize the information of a user from his/her history posts in the CQA platform, while the thread-level features model the pairwise competitions of a user with others in his/her answered threads. Finally, we extend a state-of-the-art learning-to-rank algorithm for training a multi-objective ranking model. Extensive experimental results on real-world datasets show that our MLQR can outperform state-of-the-art methods in terms of both answering possibility and answer quality. Auteurs: Xiang Cheng;Shuguang Zhu;Sen Su;Gang Chen; Apparue dans: IEEE Transactions on Knowledge and Data Engineering Date publication: 09.-2017, volume: 29, issue:9, pages: 1779 - 1792 Editeur: IEEE Document complet vers site de l'éditeur » A Multi-Stage Solution for NFV-Enabled Multicast Over the Hybrid Infrastructure  Résumé:The network function virtualization-enabled multicast problem includes constructing traffic forwarding topology, deploying required functions and steering traffic through them. Currently, jointly taking them into consideration is still an open problem and we propose a multi-stage solution to solve it. Specifically, we separate the multicast traffic forwarding and function delivery. The traffic forwarding topology is constructed with minimum spanning tree and the function delivery is implemented with the backtracking strategy. Simulation results show that the proposed solution achieves good performance. Auteurs: Bo Yi;Xingwei Wang;Min Huang;Anwei Dong; Apparue dans: IEEE Communications Letters Date publication: 09.-2017, volume: 21, issue:9, pages: 2061 - 2064 Editeur: IEEE Document complet vers site de l'éditeur » A Multivariate Approach for Patient-Specific EEG Seizure Detection Using Empirical Wavelet Transform  Résumé:Objective: This paper investigates the multivariate oscillatory nature of electroencephalogram (EEG) signals in adaptive frequency scales for epileptic seizure detection. Methods: The empirical wavelet transform (EWT) has been explored for the multivariate signals in order to determine the joint instantaneous amplitudes and frequencies in signal adaptive frequency scales. The proposed multivariate extension of EWT has been studied on multivariate multicomponent synthetic signal, as well as on multivariate EEG signals of Children's Hospital Boston-Massachusetts Institute of Technology (CHB-MIT) scalp EEG database. In a moving-window-based analysis, 2-s-duration multivariate EEG signal epochs containing five automatically selected channels have been decomposed and three features have been extracted from each 1-s part of the 2-s-duration joint instantaneous amplitudes of multivariate EEG signals. The extracted features from each oscillatory level have been processed using a proposed feature processing step and joint features have been computed in order to achieve better discrimination of seizure and seizure-free EEG signal epochs. Results: The proposed detection method has been evaluated over 177 h of EEG records using six classifiers. We have achieved average sensitivity, specificity, and accuracy values as 97.91%, 99.57%, and 99.41%, respectively, using tenfold cross-validation method, which are higher than the compared state of art methods studied on this database. Conclusion: Efficient detection of epileptic seizure is achieved when seizure events appear for long duration in hours long EEG recordings. Significance: The proposed method develops time–frequency plane for multivariate signals and builds patient-specific models for EEG seizure detection. Auteurs: Abhijit Bhattacharyya;Ram Bilas Pachori; Apparue dans: IEEE Transactions on Biomedical Engineering Date publication: 09.-2017, volume: 64, issue:9, pages: 2003 - 2015 Editeur: IEEE Document complet vers site de l'éditeur » A Nanosecond-Transient Fine-Grained Digital LDO With Multi-Step Switching Scheme and Asynchronous Adaptive Pipeline Control  Résumé:This paper introduces a multi-step switching scheme for a digital low dropout regulator (DLDO) that emerges as a new way of achieving nanosecond-transient and fine-grained on-chip voltage regulation. The multi-step switching scheme takes advantage of the adaptive pipeline control and asynchronous clocking for area- and power-efficient digital controller utilization. It speeds up the transient response by varying the pass transistor sizing in two available lengths of coarse steps as per the perturbation, while maintaining a small output voltage ripple by toggling in a finer step at steady operation. A prototype proving the proposed concept, i.e., a 0.6–1.0-V input, 50–200-mV dropout, and 500-mA maximum loading DLDO with an on-chip 1.5-nF output capacitor, is fabricated in a 65-nm CMOS process to verify the effectiveness of this scheme. By employing the multi-step switching scheme and adaptive control, the DLDO achieved a fast transient response to nanoseconds loading current change, and a 100 mV per 10-ns reference voltage switching, as well as a resolution of 768 levels (~9.5 bits) with a 5-mV output ripple. The quiescent current consumed by this DLDO at steady operation is down to$300~{\mu }\text{A}$. Auteurs: Fan Yang;Philip K. T. Mok; Apparue dans: IEEE Journal of Solid-State Circuits Date publication: 09.-2017, volume: 52, issue:9, pages: 2463 - 2474 Editeur: IEEE Document complet vers site de l'éditeur » A New Buck–Boost Converter With Low-Voltage Stress and Reduced Conducting Components  Résumé:This paper presents a new buck–boost converter. Unlike the single-switch buck–boost converter, the proposed converter has low-voltage stresses on semiconductors. Moreover, although both the conventional two-switch buck–boost (TSBB) and the proposed converters have the same number of passive and active components, and the proposed converter can reduce the conduction loss as a result of having fewer conducting components. Therefore, the proposed converter obtained a higher efficiency than the TSBB converter. A 48-V output voltage and 150-W output power prototype was fabricated to verify the effectiveness of the proposed converter. Auteurs: Hyo-Soo Son;Jae-Kuk Kim;Jae-Bum Lee;Sang-Su Moon;Ji-Hoon Park;Seok-Hyun Lee; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 09.-2017, volume: 64, issue:9, pages: 7030 - 7038 Editeur: IEEE Document complet vers site de l'éditeur » A New Electromagnetic Launcher by Sextupole Rails: Electromagnetic Propulsion and Shielding Numerical Validation  Résumé:A novel sextupole rails electromagnetic launcher has been designed and validated with numerical simulations of electromagnetic propulsion and shielding. The sextupole rails and club-shaped projectile are proposed as that the club-shaped projectile carrying the sextupole toroidal currents is surrounded by the sextupole toroidal field created from the sextupole rails. The interaction between the toroidal magnetic field and the orthogonal toroidal currents results in the generation of axial acceleration force. The sextupole rails electromagnetic launcher can solve the problems of magnetic shielding without shielding coils or materials. The theoretical assessment of the propulsion force and magnetic shielding is performed by corresponding numerical validation based on finite-element simulations. The numerical simulation results demonstrate that the sextupole rails electromagnetic launcher represents high thrust/current ratios and productive magnetic shielding effect. Auteurs: Xinpeng Xue;Tao Shu;Zhiyong Yang;Gang Feng; Apparue dans: IEEE Transactions on Plasma Science Date publication: 09.-2017, volume: 45, issue:9, pages: 2541 - 2545 Editeur: IEEE Document complet vers site de l'éditeur » A New Framework of Filter Bank Multi-Carrier: Getting Rid of Subband Orthogonality  Résumé:Filter bank multi-carrier (FBMC) entitles many advantages over orthogonal frequency division multiplexing (OFDM) and is considered to be a more competitive waveform in the future generation cellular communications. In current FBMC, the prototype filter is deliberately designed to meet the perfect reconstruction (PR) constraint to establish subband orthogonality in real domain, which may not be optimal from communication perspective. In this paper, we challenge the necessity of PR constraint by proposing a new FBMC framework, which directly accepts non-orthogonal transmission. The resulting imperfect reconstruction FBMC (iPR-FBMC) has several advantages over its PR FBMC counterpart: 1) the constraint on the prototype filter is relaxed; 2) more importantly, the prototype filter can now be optimized with new goal of improving the detection performance rather than having to meet the PR condition; and 3) it allows for more flexible subband management in multi-user scenario. We will show how those advantages can be exploited. Simulations show that with moderate increase in computational complexity, the proposed iPR-FBMC with optimized prototype filter has superior bit error rate (BER) performance to existing FBMC with PR constraint and even outperforms OFDM, especially in highly frequency selective channels. The findings may shed light into potential research on non-orthogonal FBMC without PR constraint. Auteurs: Jian Dang;Zaichen Zhang;Liang Wu;Yongpeng Wu; Apparue dans: IEEE Transactions on Communications Date publication: 09.-2017, volume: 65, issue:9, pages: 3922 - 3932 Editeur: IEEE Document complet vers site de l'éditeur » A New Harmonic Reduced Three-Phase Thyristor-Controlled Reactor for Static VAr Compensators  Résumé:A new thyristor-controlled reactor scheme is presented in this paper, in which the total bank is split into one Δ- and one Y-connected reactor bank with the addition of a low-rating zig-zag autotransformer, instead of the conventional scheme using a Δ-connected reactor bank with a harmonic current filter. This arrangement prevents the triplen harmonics generated by the Y bank from entering into the supply system and at the same time, the combination results in cancellation of some major characteristic harmonics from the source current. Thus, without using any additional filters or phase-shifting two-winding transformer, this scheme facilitates reactive power control over a wide range and also meets the requisite harmonics standards. The scheme is simple and provides a cost-effective solution to the VAr compensation problem. Simulation and experimental results are provided to validate the proposed concept. Auteurs: Susovan Mukhopadhyay;Dipten Maiti;Ambarnath Banerji;Sujit K. Biswas;Nirmal K. Deb; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 09.-2017, volume: 64, issue:9, pages: 6898 - 6907 Editeur: IEEE Document complet vers site de l'éditeur » A New Kind of Article for Reproducible Research in Intelligent Robotics [From the Field]  Résumé: Auteurs: Fabio Bonsignorio; Apparue dans: IEEE Robotics & Automation Magazine Date publication: 09.-2017, volume: 24, issue:3, pages: 178 - 182 Editeur: IEEE Document complet vers site de l'éditeur » A New Model for Resilient Distribution Systems by Microgrids Formation  Résumé:Forming multiple micorgrids with distributed generators offers a resilient solution to restore critical loads from natural disasters in distribution systems. However, more dummy binary and continuous variables are needed with the increase of the number of microgrids, which will therefore increase the complexity of this model. To address this issue, this letter presents a new model to reformulate the micorgrid formulation problem in resilient distribution networks. Compared with the traditional model, the number of both binary and continuous variables is greatly reduced, such that the computational performance is significantly improved. Numerical results on IEEE test systems verify the effectiveness of the proposed model. Auteurs: Tao Ding;Yanling Lin;Gengfeng Li;Zhaohong Bie; Apparue dans: IEEE Transactions on Power Systems Date publication: 09.-2017, volume: 32, issue:5, pages: 4145 - 4147 Editeur: IEEE Document complet vers site de l'éditeur » A New Paradigm for Spectrum Sharing Between Cellular Wireless Communications and Radio Astronomy Systems  Résumé:This paper proposes a new paradigm for spectrum sharing between cellular wireless communications (CWC) and radio astronomy systems (RAS). In contrast to the existing paradigm of geographical and spectral isolation between CWC and RAS, this paper develops a three phase spectrum access, which enables geographical and spectral coexistence between CWC and RAS. Shared spectrum access zone (SSAZ) is created around the RAS site and CWC cells within the SSAZ follow the three phase spectrum access scheme while those outside the SSAZ have full spectrum access. In addition, system characteristics-based improved spectrum sharing is developed. Furthermore, a built-in fine tuning mechanism is presented for addressing mismatches between design and practical environments as well as for facilitating service evolutions. Performance evaluation results demonstrate that the proposed paradigm offers 1) certain guaranteed spectrum access to RAS, which is impossible in the existing paradigm, 2) capability to handle higher peak and mean traffics to CWC under spectrum restructuring of both CWC and RAS bands, and 3) overall improved spectrum utilization. Auteurs: Yahia R. Ramadan;Hlaing Minn;Yucheng Dai; Apparue dans: IEEE Transactions on Communications Date publication: 09.-2017, volume: 65, issue:9, pages: 3985 - 3999 Editeur: IEEE Document complet vers site de l'éditeur » A New State-of-Charge Control Derivation Method for Hybrid Battery Type Integration  Résumé:The hybrid of ex-transportation and conventional new battery system integration has started gaining interests within energy storage systems as number of electric vehicle on-road increases. Each module within such a system may consist of batteries with different charging/discharging rates, characteristics and also different nominal voltage levels. Control of these hybrid batteries within the same system is more challenging compared to conventional battery management systems, which mainly deal with the homogeneous battery system. One of the key issues is how to control the state-of-charge trajectory of the hybrid modules to maximize the investment on the new hybrid battery system. To cater this problem, this paper brings a new rigorous derivation method of state-of-charge control based on converter sample time. The proposed method generates desired current reference in each time step to distribute the power among hybrid modules such that their discharging or charging trajectories finish at the same time. This technique makes sure that the energy delivered/absorbed from each cell in a uniform manner maximizing the overall lifespan. Detailed derivation of the current sharing method and suitable module based adaptive bidirectional control architecture has also been presented. Modeling, analysis, and experimental validations are performed on a three-module-based grid-tie hybrid battery energy storage system prototype to validate analysis. Auteurs: Nilanjan Mukherjee;Dipankar De; Apparue dans: IEEE Transactions on Energy Conversion Date publication: 09.-2017, volume: 32, issue:3, pages: 866 - 875 Editeur: IEEE Document complet vers site de l'éditeur » A New Way for a New Generation [Editorial]  Résumé: Auteurs: Cristian Quintero; Apparue dans: IEEE Potentials Date publication: 09.-2017, volume: 36, issue:5, pages: 3 - 3 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Adaptive Fuzzy Local Information$C-Means Clustering Algorithm for Remotely Sensed Imagery Classification  Résumé:This paper presents a novel adaptive fuzzy local information c-means (ADFLICM) clustering approach for remotely sensed imagery classification by incorporating the local spatial and gray level information constraints. The ADFLICM approach can enhance the conventional fuzzy c-means algorithm by producing homogeneous segmentation and reducing the edge blurring artifact simultaneously. The major contribution of ADFLICM is use of the new fuzzy local similarity measure based on pixel spatial attraction model, which adaptively determines the weighting factors for neighboring pixel effects without any experimentally set parameters. The weighting factor for each neighborhood is fully adaptive to the image content, and the balance between insensitiveness to noise and reduction of edge blurring artifact to preserve image details is automatically achieved by using the new fuzzy local similarity measure. Four different types of images were used in the experiments to examine the performance of ADFLICM. The experimental results indicate that ADFLICM produces greater accuracy than the other four methods and hence provides an effective clustering algorithm for classification of remotely sensed imagery. Auteurs: Hua Zhang;Qunming Wang;Wenzhong Shi;Ming Hao; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 09.-2017, volume: 55, issue:9, pages: 5057 - 5068 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Approach to Array Manifold Calibration Using Single-Direction Information for Accurate Direction-of-Arrival Estimation  Résumé:A method of array manifold calibration using one steering vector measured in a single direction is proposed. The phase information of the measured steering vector is used to derive a novel calibration matrix that is proposed to compensate for the relative phase distortion (RPD) at each antenna port. We also present a metric function defined as a standard deviation of the RPD to determine the optimum calibration angle, which provides intuition for the cause of the accuracy degradation in the direction-of-arrival estimation. To verify the feasibility, a seven-element circular array with identical microstrip patch antennas is fabricated for calibrating its array manifold using a single steering vector measured in a full anechoic chamber. The calibrated array manifold is then used to estimate the direction of arrival, and its accuracy is compared to the calibrated result obtained from the traditional least-squares method. The results demonstrate that the estimation error can be improved by 54.9° compared to the traditional least-squares method, when the number of measured steering vectors is extremely limited. Auteurs: Gangil Byun;Hosung Choo; Apparue dans: IEEE Transactions on Antennas and Propagation Date publication: 09.-2017, volume: 65, issue:9, pages: 4952 - 4957 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Autonomous Initial Alignment Method for Strapdown Inertial Navigation System  Résumé:In-motion alignment of strapdown inertial navigation systems (SINS) without any geodetic-frame observations is one of the toughest challenges for autonomous vehicles. Considering the characteristics of SINS, this paper presents a dual-model-based in-motion alignment method for the odometer-aided SINS. Two inertial navigation calculation loops are established for an inertial measurement unit (IMU), one of which executes the in-motion gyrocompass horizontal alignment algorithm to decompose the body velocity measured by odometer to navigation frame and attenuate the disturbance. And the other is the attitude determination-based alignment loop, where the vector observation-based SINS alignment is executed. The contributions of the work presented here are twofold. First, the dual-model initial alignment (DMIA) algorithm for SINS is proposed, which introduces the idea of constructing multiple calculation loops for an IMU to maximize the advantages of SINS. Second, depending on the body-frame speed-aided attitude determination and navigation-frame speed-aided attitude determination, the body-frame velocity observation with disturbance is accurately decomposed to navigation frame with the noise attenuated by gyrocompass horizontal alignment. The experimental results show that the proposed DMIA algorithm can achieve a rapid and accurate in-motion alignment. Auteurs: Jiangning Xu;Hongyang He;Fangjun Qin;Lubin Chang; Apparue dans: IEEE Transactions on Instrumentation and Measurement Date publication: 09.-2017, volume: 66, issue:9, pages: 2274 - 2282 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Bayesian Spatial–Temporal Random Field Model Applied to Cloud Detection From Remotely Sensed Imagery  Résumé:With the fast advancement of remote sensing platforms and sensors, remotely sensed imagery (RSI) is increasingly being characterized by both high spatial resolution and high temporal resolution. How to efficiently use the rich spatial and temporal information in RSI for highly accurate object detection and classification is an important research question. Nevertheless, there is still a lack of a probabilistic framework that is capable of fully accounting for the spatial–temporal information in RSI for improved applications. In this paper, we present a Bayesian spatial–temporal random field model that constitutes a complete probabilistic framework for fully explaining the spatial–temporal correlation in RSI, leading to an enhanced object detection approach that is used for cloud detection from RSI. Under the Bayesian theorem, the posterior distribution of a label field is decomposed into the label prior, the data likelihood, the temporal label likelihood, and the temporal data likelihood. To address the difficulties in modeling the complex spatial–temporal correlation effect in the temporal data likelihood, a stochastic sampling approach is presented. Based on the maximum a posteriori approach, the posterior distribution is seamlessly integrated into the graph-cut optimization framework, and, therefore, the model optimization can be efficiently solved. The proposed algorithm is tested for cloud detection on both simulated and real RSIs and the results demonstrate that the proposed algorithm can effectively exploit the spatial–temporal information for achieving higher detection accuracy. Auteurs: Linlin Xu;Alexander Wong;David A. Clausi; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 09.-2017, volume: 55, issue:9, pages: 4913 - 4924 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Cross-Feedback Notch Filter for Synchronous Vibration Suppression of an MSFW With Significant Gyroscopic Effects  Résumé:To effectively suppress the synchronous vibration torques for a magnetically suspended rotor (MSR) with significant gyroscopic effects and serious coupling dynamics, a novel cross-feedback notch filter is proposed in this paper. First, the coupled multi-input-multi-output active magnetic bearing rotor system is converted into an equivalent complex single-input single-output (SISO) system. The equivalent transformation aims at easing the controller design and extending the classical stability criterion to the complex coefficient frequency domain. Then, the principle and implementation of the proposed scheme used for synchronous vibration suppression over an entire rotational speed range is analyzed in details. The performance compared with the conventional decentralized notch filter is investigated. Moreover, the closed-loop stability, which based on the equivalent complex SISO system and complex-coefficient stability criterion is given. Experimental results on a magnetically suspended flywheel demonstrate the significant effect of the proposed method on both synchronous vibration suppression and stability preservation. Auteurs: Cong Peng;Jinji Sun;Cunxiao Miao;Jiancheng Fang; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 09.-2017, volume: 64, issue:9, pages: 7181 - 7190 Editeur: IEEE Document complet vers site de l'éditeur » A Novel DC-Power Control Method for Cascaded H-Bridge Multilevel Inverter  Résumé:The cascaded H-bridge converter has been widely used in industry. The ability of dealing with unequal power generation among dc links is necessarily required in many applications, such as large-scale photovoltaic power plants and electric vehicles. In this paper, a novel dc-power control method (PCM) is proposed to keep the ac-current balance and maintain power generation ratios of each dc source at their expected values. A simplified modulation strategy is introduced to implement the proposed method, in which the duration times are modified directly by the correction value derived from the PCM method. To calculate and adjust the power generation ratios, a method based on first-in first-out (FIFO) data queue is utilized. The limitation and ranges of power generation ratio are analyzed in detail. DC power per phase can be controlled accurately by the proposed method in variable-frequency condition, even under larger power generation ratios. Results obtained from simulations and experiments are presented to verify the feasibilities and superiorities of the proposed method. Auteurs: Zongbin Ye;Linlin Jiang;Zhiguo Zhang;Dongsheng Yu;Zhichuan Wang;Xianming Deng;Tyrone Fernando; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 09.-2017, volume: 64, issue:9, pages: 6874 - 6884 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Elastic Force-Field to Influence Mediolateral Foot Placement During Walking  Résumé:Bipedal gait can be stabilized through mechanically-appropriate mediolateral foot placement, although this strategy is disrupted in a subset of neurologically injured individuals with balance deficits. The goal of the present work was to develop a device to influence mediolateral foot placement during treadmill walking. We created a novel force-field using a combination of passive elasticity and active control; wires in series with extension springs run parallel to the treadmill belts and can be rapidly repositioned to exert mediolateral forces on the legs of users. This mechanical structure creates a channel-like force landscape that resists displacements of each leg away from its prescribed mediolateral position, producing near-linear effective mediolateral stiffness. The depth of these force-field channels can be predictably controlled by manipulating extension spring initial tension. In human testing, we found that the force-field can effectively “get-out-of-the-way” when desired, closely following the mediolateral leg trajectory with a delay of approximately 110 ms. The force-field can also encourage users to adjust their mediolateral foot placement in order to walk with either narrower or wider steps, without interfering with forward gait progression. Future work will test whether this novel device can help retrain a stable gait pattern in clinical populations. Auteurs: Elizabeth T. Nyberg;Jordan Broadway;Christian Finetto;Jesse C. Dean; Apparue dans: IEEE Transactions on Neural Systems and Rehabilitation Engineering Date publication: 09.-2017, volume: 25, issue:9, pages: 1481 - 1488 Editeur: IEEE Document complet vers site de l'éditeur » A Novel GNSS Technique for Predicting Boreal Forest Attributes at Low Cost  Résumé:One of the biggest challenges in forestry research is the effective and accurate measuring and monitoring of forest variables, as the exploitation potential of forest inventory products largely depends on the accuracy of estimates and on the cost of data collection. This paper presented a novel computational method of low-cost forest inventory using global navigation satellite system (GNSS) signals in a crowdsourcing approach. Statistical features of GNSS signals were extracted from widely available GNSS devices and were used for predicting forest attributes, including tree height, diameter at breast height, basal area, stem volume, and above-ground biomass, in boreal forest conditions. The basic evidence of the predictions is the physical correlations between forest variables and the responses of GNSS signals penetrating through the forest. The random forest algorithm was applied to the predictions. GNSS-derived prediction accuracies were comparable with those of the most accurate 2-D remote sensing techniques, and the predictions can be improved further by integration with other publicly available data sources without additional cost. This type of crowdsourcing technique enables the collection of up-to-date forest data at low cost, and it significantly contributes to the development of new reference data collection techniques for forest inventory. Currently, field reference can account for half of the total costs of forest inventory. Auteurs: Jingbin Liu;Juha Hyyppä;Xiaowei Yu;Anttoni Jaakkola;Antero Kukko;Harri Kaartinen;Lingli Zhu;Xinlian Liang;Yunsheng Wang;Hannu Hyyppä; Apparue dans: IEEE Transactions on Geoscience and Remote Sensing Date publication: 09.-2017, volume: 55, issue:9, pages: 4855 - 4867 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Hardware-Efficient Cochlea Model Based on Asynchronous Cellular Automaton Dynamics: Theoretical Analysis and FPGA Implementation  Résumé:A novel cochlear model based on the nonlinear dynamics of an asynchronous cellular automaton is presented. Theoretical bifurcation analyses show that the model can mimic a nonlinear vector field of a differential equation cochlea model. It is then shown that the presented model can reproduce biologically measured frequency tuning curves of multiple species. In addition, the presented model is implemented in a field programmable gate array and experiments validate reproductions of the biological tuning curves. It is also shown that the presented model can be implemented by fewer hardware resources as compared to the differential equation cochlea model. Auteurs: Kentaro Takeda;Hiroyuki Torikai; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1107 - 1111 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Hybrid Dual-PM Machine Excited by AC With DC Bias for Electric Vehicle Propulsion  Résumé:This paper proposes a novel hybrid-excited dual-PM machine for electric vehicle propulsion. The key is to use an integrated stator winding to replace the armature winding and the field winding in the conventional hybrid-excited machine. The stator winding is excited by ac current with dc bias, in which the ac component is used to produce the rotating armature field, while the dc bias current is used for the flux regulation. Therefore, the function of the ac and dc windings can be incorporated and realized by using just one set of winding. The torque density and flux regulating capability can be improved, and the winding configuration is also simplified. In addition, dual-PM excitation structure combines the advantage of stator-PM doubly salient machine and rotor-PM magnetic-geared machine, which can further enhance the torque capability. The operating principle and control strategy of the proposed machine are discussed. The electromagnetic performances are studied using the time-stepping finite-element method. A machine prototype is manufactured and experimental tests are conducted to verify the effectiveness of the machine design. Auteurs: Qingsong Wang;Shuangxia Niu;Xiang Luo; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 09.-2017, volume: 64, issue:9, pages: 6908 - 6919 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Implant Electrode Design Safe in the RF Field of MRI Scanners  Résumé:Patients with medical implants are often unable to receive magnetic resonance imaging (MRI) diagnostic treatment, because the conductive leads can concentrate the RF excitation field and generate dangerous heating of nervous tissue. We propose a simple, low-cost solution that minimizes RF heating through the addition of one or more mutually coupled filars to the lead without significant increase in lead diameter. Simulations and measurements at 128 MHz are presented to verify the effect in 3 T MRI machines. Auteurs: Steven McCabe;Jonathan Scott; Apparue dans: IEEE Transactions on Microwave Theory and Techniques Date publication: 09.-2017, volume: 65, issue:9, pages: 3541 - 3547 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Linearization Variant of Reliability Costs in the Optimal Scheduling Model  Résumé:Reliability costs are used to evaluate the influence of large-scale wind power integration on security constrained unit commitment (SCUC), but the nonlinear expressions of reliability costs increase the complexity of the SCUC model. To address this issue, this letter presents a novel variant to exactly linearize the nonlinear expressions. Compared with the traditional approach, the proposed variant can reduce the number of binary variables, such that the computational performance of the SCUC model is significantly improved. Numerical results of the IEEE reliability test system verify the effectiveness of the proposed variant. Auteurs: Jiajun Lv;Tao Ding;Zhaohong Bie;Xifan Wang; Apparue dans: IEEE Transactions on Power Systems Date publication: 09.-2017, volume: 32, issue:5, pages: 4140 - 4142 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Mirror-Aided Non-Imaging Receiver for Indoor2\times 2$MIMO-Visible Light Communication Systems  Résumé:Indoor visible light communication (VLC) systems are now possible because of advances in light emitting diode and laser diode technologies. These lighting technologies provide the foundation for multiple-input multiple-output (MIMO) data transmission through visible light. However, the channel matrix can be strongly correlated in indoor MIMO-VLC systems, preventing parallel data streams from being decoded. Here, in$2\times 2$MIMO-VLC systems, we describe a mirror diversity receiver (MDR) design that reduces the channel correlation by both blocking the reception of light from one specific direction and improving the channel gain from light from another direction by utilizing a double-sided mirror deployed between the receiver’s photodetectors. We report on the channel capacity of the MDR system and the optimal height of its mirrors in terms of maximum channel capacity. We also derived analytic results on the effect of rotation on MDR’s performance. Based on numerical and experimental results, we show that the double-sided mirror has both constructive and destructive effects on the channel matrix. Our design can be used with previously described non-imaging systems to improve the performance of indoor VLC systems. Auteurs: Ki-Hong Park;Hassan Makine Oubei;Wael G. Alheadary;Boon S. Ooi;Mohamed-Slim Alouini; Apparue dans: IEEE Transactions on Wireless Communications Date publication: 09.-2017, volume: 16, issue:9, pages: 5630 - 5643 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Mirror-Aided Non-Imaging Receiver for Indoor$2\times 2$MIMO-Visible Light Communication Systems  Résumé:Indoor visible light communication (VLC) systems are now possible because of advances in light emitting diode and laser diode technologies. These lighting technologies provide the foundation for multiple-input multiple-output (MIMO) data transmission through visible light. However, the channel matrix can be strongly correlated in indoor MIMO-VLC systems, preventing parallel data streams from being decoded. Here, in$2\times 2$MIMO-VLC systems, we describe a mirror diversity receiver (MDR) design that reduces the channel correlation by both blocking the reception of light from one specific direction and improving the channel gain from light from another direction by utilizing a double-sided mirror deployed between the receiver’s photodetectors. We report on the channel capacity of the MDR system and the optimal height of its mirrors in terms of maximum channel capacity. We also derived analytic results on the effect of rotation on MDR’s performance. Based on numerical and experimental results, we show that the double-sided mirror has both constructive and destructive effects on the channel matrix. Our design can be used with previously described non-imaging systems to improve the performance of indoor VLC systems. Auteurs: Ki-Hong Park;Hassan Makine Oubei;Wael G. Alheadary;Boon S. Ooi;Mohamed-Slim Alouini; Apparue dans: IEEE Transactions on Wireless Communications Date publication: 09.-2017, volume: 16, issue:9, pages: 5630 - 5643 Editeur: IEEE Document complet vers site de l'éditeur » A Novel MMF Distribution Model for 3-D Analysis of Linear Induction Motor With Asymmetric Cap-Secondary for Metro  Résumé:This paper develops a novel magnetomotive forces (mmfs) distribution model along the transverse direction for the 3-D analysis of linear induction motor, and it investigates the influence of a laterally asymmetric cap-secondary on the thrust, vertical force, lateral force, and efficiency in a prototype single-sided linear induction motor for linear metro. First, the mmf distribution model and its working conditions are defined, and the model is transferred into a mathematical model. Second, the air-gap flux and secondary eddy current in a prototype linear motor with a cap-secondary are obtained by a 3-D space harmonic analytical method. Third, the thrust, vertical force, lateral force, and efficiency of the test motor are analyzed with various lateral deflection, and the power factor in secondary is also presented. Finally, these results are experimentally verified by measurements on the test rig of the linear motor, and the comprehensive effect on the operating performance can be accurately calculated by the mmf model. Auteurs: Gang Lv;Dihui Zeng;Tong Zhou; Apparue dans: IEEE Transactions on Magnetics Date publication: 09.-2017, volume: 53, issue:9, pages: 1 - 7 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Reactive Survivable Virtual Network Embedding Scheme Based on Game Theory  Résumé:In this paper, we tackle the virtual network (VN) embedding problem within Cloud’s backbone network by taking into consideration the impact of physical equipment outages. Our main focus is to improve the Cloud provider’s (CPs) revenue by: 1) maximizing the acceptance rate of VNs within the Cloud’s backbone and 2) minimizing the penalties induced by service disruption due to the hardware outages. This optimization problem is non-linear multi-objective and it has been proven to be NP-hard. To cope with this complexity, we propose an advanced coordination game for VN embedding (Advanced-CG-VNE). In this mapping (i.e., embedding) game, fictitious players are playing on behalf of the CP in order to maximize the turnover. The decision makers cooperate in aim to converge to a Nash Equilibrium that we prove the existence of and the matching with a social optimum. Two variants of Advanced-CG-VNE are proposed according to the virtual links embedding approach. The first one, denoted by Advanced-CG-VNE-unsplittable, embeds each virtual link in only one substrate path. The second variant, denoted by Advanced-CG-VNE-splittable, dispatches the required bandwidth of a virtual link among a set of substrate paths. Advanced-CG-VNE does not allocate any backup to handle service interruption caused by hardware failures. Our proposal adopts preventive and reactive mechanisms to palliate substrate failures. Based on extensive simulations to gauge the effectiveness of Advanced-CG-VNE, the obtained results show that our proposal outperforms the most prominent related strategies in terms of: 1) rejection rate of VNs; 2) rate of VNs impacted by physical failures; and 3) CPs turnover. Auteurs: Oussama Soualah;Nadjib Aitsaadi;Ilhem Fajjari; Apparue dans: IEEE Transactions on Network and Service Management Date publication: 09.-2017, volume: 14, issue:3, pages: 569 - 585 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Subspace Based Method for Compensation of Multiple CFOs in Uplink MIMO OFDM Systems  Résumé:The tri-linear data model for an arbitrary multi-user uplink multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) system comprising orthogonal frequency division multiplexing access users and co-channel (CC) users is formulated in this letter. A novel subspace-based method for multi-access interference cancellation and CC data separation in multi-user MIMO OFDM systems, utilizing the independent manifolds spanned by user’s carrier frequency offset matrix, is proposed in this letter. The system constraints under which the proposed subspace nulling method works are derived, which includes the under-determined cases, where minimum mean square error/zero forcing methods fail. Auteurs: Avik Santra;K. V. S. Hari; Apparue dans: IEEE Communications Letters Date publication: 09.-2017, volume: 21, issue:9, pages: 1993 - 1996 Editeur: IEEE Document complet vers site de l'éditeur » A Novel Wearable Apparatus to Measure Fingertip Forces in Manipulation Tasks Based on MEMS Barometric Sensors  Résumé:Artificial tactile sensing is a challenging research topic in robotics, motor control, and rehabilitation engineering encompassing multi-disciplinary skills and different technologies. This paper presents the development of a wearable tactile thimble system using MEMS barometric sensors and flexible printed circuit board. Barometric sensors were carefully processed to make them able to transduce contact forces. Thumb, index, and medium fingers were equipped with an array of six sensing elements each, covering the central, lateral, and medial aspects of the fingertip. The sensor integration, signal read-out and processing, hardware architecture of the device, along with the calibration protocol, were described. The test results showed adequate sensitivity at very low forces with an almost linear transduction range up to about 4N (RMSE: 0.04N). Tests on object manipulation tasks highlighted the value of the proposed system demonstrating the ability of measuring both the force amplitude and contact points, demonstrating the suitability of barometric sensors for tactile applications. Auteurs: Pietro Cerveri;Mauro Quinzi;Dario Bovio;Carlo Albino Frigo; Apparue dans: IEEE Transactions on Haptics Date publication: 09.-2017, volume: 10, issue:3, pages: 317 - 324 Editeur: IEEE Document complet vers site de l'éditeur » A Parallel Transportation Management and Control System for Bus Rapid Transit Using the ACP Approach  Résumé:Bus rapid transit (BRT) has been proved to be an effective tool to improve mass transit services. However, BRT's adaptive operations like management and scheduling under different scenarios are too complicated to implement using traditional methods. The ACP approach, which is based on holism and complex system theory and consists of artificial systems (A), computational experiments (C) and parallel execution (P), offers an efficient new method to cope with these complex systems, including BRT. In this paper, the parallel transportation management and control system for BRT (PTMS-BRT) is presented, which is designed and implemented using the ACP approach. PTMS-BRT integrates such functions as BRT's monitoring, warning, forecasting, incident management, and real-time scheduling, to provide its operations smoother, safer, more efficient, and reliable. It has been piloted successfully in Guangzhou BRT to demonstrate it as another successful example of parallel transportation systems. Auteurs: Xisong Dong;Yuetong Lin;Dayong Shen;Zhengxi Li;Fenghua Zhu;Bin Hu;Dong Fan;Gang Xiong; Apparue dans: IEEE Transactions on Intelligent Transportation Systems Date publication: 09.-2017, volume: 18, issue:9, pages: 2569 - 2574 Editeur: IEEE Document complet vers site de l'éditeur » A Parity Structure for Scalable QC-LDPC Codes With All Nodes of Degree Three  Résumé:A novel block triple-diagonal (BTD) parity structure with all nodes of degree three is proposed for quasi-cyclic (QC) low-density parity-check (LDPC) codes. The BTD structure without low node degree can effectively improve the error floor performance and, meanwhile, enable low complexity encoding. With this structure, we use a modulo-lifting technology to construct a family of QC-LDPC codes, which supports scalable code lengths with a simple and flexible encoding solution. The simulation results show that our coding schemes for short and moderate lengths achieve better performance in the error floor region. Auteurs: Xiaoning Wu;Ming Jiang;Chunming Zhao; Apparue dans: IEEE Communications Letters Date publication: 09.-2017, volume: 21, issue:9, pages: 1913 - 1916 Editeur: IEEE Document complet vers site de l'éditeur » A Passive Imaging System for Geometry Measurement for the Plasma Arc Welding Process  Résumé:Automatic and flexible geometry measurement of the weld pool surface can help better understand the complex welding processes and even provide feedback to better control this process. Most of existing imaging systems use an additional source of illumination to remove the light interference coming from the welding arc but it is usually costly. This paper introduces a novel low-cost optical-sensor-based monitoring system working under passive mode to monitor the wire + arc additive manufacture process, particularly for plasma arc welding. Initially, configurations and parameters of camera are investigated to achieve good visualization of weld pool. A novel camera calibration methodology using the nozzle of a computer numerical control (CNC) machine is then proposed for this imaging system, allowing estimation of the camera position with respect to the inspecting surface and its orientation in an easy-to-use approach. The verification tests show that the average error of the calibration is less than 1 pixel. As a case study, an image analysis routine is proposed to measure the width of the bead during the welding process. The results show that the proposed system is effective to measure the dimension of weld pool. Auteurs: Tomas Font comas;Chenglei Diao;Jialuo Ding;Stewart Williams;Yifan Zhao; Apparue dans: IEEE Transactions on Industrial Electronics Date publication: 09.-2017, volume: 64, issue:9, pages: 7201 - 7209 Editeur: IEEE Document complet vers site de l'éditeur » A Physics-Based Vibrotactile Feedback Library for Collision Events  Résumé:We present PhysVib: a software solution on the mobile platform extending an open-source physics engine in a multi-rate rendering architecture for automatic vibrotactile feedback upon collision events. PhysVib runs concurrently with a physics engine at a low update rate and generates vibrotactile feedback commands at a high update rate based on the simulation results of the physics engine using an exponentially-decaying sinusoidal model. We demonstrate through a user study that this vibration model is more appropriate to our purpose in terms of perceptual quality than more complex models based on sound synthesis. We also evaluated the perceptual performance of PhysVib by comparing eight vibrotactile rendering methods. Experimental results suggested that PhysVib enables more realistic vibrotactile feedback than the other methods as to perceived similarity to the visual events. PhysVib is an effective solution for providing physically plausible vibrotactile responses while reducing application development time to great extent. Auteurs: Gunhyuk Park;Seungmoon Choi; Apparue dans: IEEE Transactions on Haptics Date publication: 09.-2017, volume: 10, issue:3, pages: 325 - 337 Editeur: IEEE Document complet vers site de l'éditeur » A Piggybacking Design Framework for Read-and Download-Efficient Distributed Storage Codes  Résumé:Erasure codes are being extensively deployed in distributed storage systems instead of replication to achieve fault tolerance in a storage efficient manner. While traditional erasure codes are storage efficient, they can result in a significant increase in the amount of data access and downloaded during rebuilding of failed or otherwise unavailable nodes. In this paper, we present a new framework, which we call piggybacking, for constructing distributed storage codes that are efficient in the amount of data read and downloaded during rebuilding, while meeting requirements arising out of system considerations in data centers—maximum-distance-separability (MDS), high-rate, and a small number of so-called substripes. Under this setting, to the best of our knowledge, piggyback codes achieve the minimum average amount of data access and downloaded during rebuilding among all existing explicit solutions. The piggybacking framework also offers a rich design space for constructing codes for a variety of other settings. In particular, we construct codes that require minimum amount of data access and downloaded for rebuilding among all existing solutions for: 1) binary MDS array codes with more than two parities and 2) MDS codes with the smallest locality during rebuilding. In addition, we show how piggybacking can be employed to enable efficient repair of parity nodes in codes that address the rebuilding of only systematic nodes. The basic idea behind the piggybacking framework is to take multiple instances of existing codes and add carefully designed functions of the data from one instance to the others. This framework provides 25% to 50% savings in the average amount of data access and downloaded during rebuilding depending on the choice of the code parameters. Auteurs: K. V. Rashmi;Nihar B. Shah;Kannan Ramchandran; Apparue dans: IEEE Transactions on Information Theory Date publication: 09.-2017, volume: 63, issue:9, pages: 5802 - 5820 Editeur: IEEE Document complet vers site de l'éditeur » A Power-Efficient Signal-Specific ADC for Sensor-Interface Applications  Résumé:A novel signal-specific power-efficient analog-to-digital converter (ADC) is proposed for sensor-interface applications. Instead of digitizing each analog sample independently, the proposed ADC determines the digital code corresponding to each new input sample by digitizing the difference of two consecutive samples. Therefore, for the applications with low-varying input signals, such as image sensors and ECG readouts, the difference of two consecutive samples is much smaller than the ADC full-scale range for the majority of the input samples, the power consumption of the capacitive digital-to-analog converter, the comparator, and the digital circuits of the proposed ADC is saved due to reducing the ADC activity. The prototype was fabricated using a 0.18-${\mu }\text{m}$CMOS technology. Measurement results of 1 V, 8 bit, 20 kS/s ADC confirm that for a 10-kHz input sine wave, the effective number of bits is 7 while the power consumption of the entire ADC is 1.12$ {\mu }\text{W}\$ . However, for the same sampling rate, the power consumption is only 106 nW for a low-varying 100-Hz input sine wave. Auteurs: Ehsan Rahiminejad;Mehdi Saberi;Reza Lotfi; Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs Date publication: 09.-2017, volume: 64, issue:9, pages: 1032 - 1036 Editeur: IEEE Document complet vers site de l'éditeur

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