#### Electrical and Electronics Engineering publications abstract of: 09-2017 sorted by title, page: 0

» $L/S$ -Band Frequency Reconfigurable Multiscale Phased Array Antenna With Wide Angle Scanning
 Abstract: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. Autors: Nadia Haider;Alexander G. Yarovoy;Antoine G. Roederer; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4519 - 4528 Publisher: IEEE
» ${W}$ -Band Direct-Modulation >20-Gb/s Transmit and Receive Building Blocks in 32-nm SOI CMOS
 Abstract:This paper presents Gb/s-speed circuit building blocks in 32-nm CMOS SOI, for a > 20-Gb/s Cartesian direct-modulation -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 -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 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 -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 Autors: Hasan Al-Rubaye;Gabriel M. Rebeiz; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2277 - 2291 Publisher: IEEE
» ${W}$ -Band Time-Domain Multiplexing FMCW MIMO Radar for Far-Field 3-D Imaging
 Abstract:In this paper, a radar demonstrator system with real-time capability operating at -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. Autors: 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; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3474 - 3484 Publisher: IEEE
» 0.5–20-GHz UWB Distributed Combiners and Dividers for Multi-Antenna Transceivers
 Abstract: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. Autors: Paolo Valerio Testa;Corrado Carta;Marvin Barahona;Frank Ellinger; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3087 - 3098 Publisher: IEEE
» 1-D Fast Neutron Source Localization Using Digital Pixelated 3-D Position-Sensitive CdZnTe Detectors
 Abstract: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°. Autors: David Goodman;Michael Streicher;Yuefeng Zhu;Steven Brown;Zhong He; Appeared in: IEEE Transactions on Nuclear Science Publication date: Sep 2017, volume: 64, issue:9, pages: 2531 - 2535 Publisher: IEEE
» 11th?IEEE UAE Student Day Hosted by Al Ain University [Around the Globe]
 Abstract:Presents information on the 11th IEEE UAE Student Day. Autors: Nazih Khaddaj Mallat; Appeared in: IEEE Microwave Magazine Publication date: Sep 2017, volume: 18, issue:6, pages: 137 - 138 Publisher: IEEE
» 16th Mediterranean Microwave Symposium Hosted by Al Ain University [Conference Report]
 Abstract:Presents information on the 16th Mediterranean Microwave Symposium. Autors: Nazih Khaddaj Mallat; Appeared in: IEEE Microwave Magazine Publication date: Sep 2017, volume: 18, issue:6, pages: 132 - 134 Publisher: IEEE
» 2-D High-Order DGTD Method and Its Application in Analysis of Sheath Propagation Characteristics
 Abstract: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. Autors: Linqian Li;Bing Wei;Qian Yang;Xin Yang;Debiao Ge; Appeared in: IEEE Transactions on Plasma Science Publication date: Sep 2017, volume: 45, issue:9, pages: 2422 - 2430 Publisher: IEEE
» 2017 IEEE\/IFR Award for IERA [Industrial Activities]
 Abstract: Autors: Erwin Prassler;Arturo Baroncelli; Appeared in: IEEE Robotics & Automation Magazine Publication date: Sep 2017, volume: 24, issue:3, pages: 8 - 11 Publisher: IEEE
» 45–110 GHz Quad-Ridge Horn With Stable Gain and Symmetric Beam
 Abstract: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 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. Autors: Sara Manafi;Muhannad Al-Tarifi;Dejan S. Filipovic; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4858 - 4863 Publisher: IEEE
» 64 × 0.5 Gbaud Nonlinear Frequency Division Multiplexed Transmissions With High Order Modulation Formats
 Abstract: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. Autors: Son Thai Le;Henning Buelow; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:17, pages: 3692 - 3698 Publisher: IEEE
» In Vivo High-Efficiency Wireless Power Transfer With Multisine Excitation
 Abstract: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. Autors: Zhongtao Liu;Zheng Zhong;Yong-Xin Guo; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3530 - 3540 Publisher: IEEE
» In Vivo Intracardiac Vector Flow Imaging Using Phased Array Transducers for Pediatric Cardiology
 Abstract: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. Autors: Solveig Fadnes;Morten Smedsrud Wigen;Siri Ann Nyrnes;Lasse Lovstakken; Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control Publication date: Sep 2017, volume: 64, issue:9, pages: 1318 - 1326 Publisher: IEEE
» A $2 Million Contest Seeks Solutions [Spectral Lines]  Abstract: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. Autors: Tekla S. Perry; Appeared in: IEEE Spectrum Publication date: Sep 2017, volume: 54, issue:9, pages: 8 - 8 Publisher: IEEE
» A $K$ -Band Portable FMCW Radar With Beamforming Array for Short-Range Localization and Vital-Doppler Targets Discrimination
 Abstract:This paper presents a printed circuit board realization of a -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 -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. Autors: Zhengyu Peng;Lixin Ran;Changzhi Li; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3443 - 3452 Publisher: IEEE
» A ${Z}$ -Transform Method for Synthesis of Unequal-Length Multisection Transmission Lines for Multiband Applications
 Abstract:A method based on the -transform is demonstrated to cascade transmission line sections of unequal lengths and achieve multiband and/or wideband properties. Unlike previous methods based on the -transform, the proposed method associates the term with the infinitesimal length of the unit segment. Consequently, any electrical length can be expressed in the 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 -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. Autors: Joonsuk Kim;Yongshik Lee; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3200 - 3210 Publisher: IEEE
» A 0.3-V 1- $\mu \text{W}$ Super-Regenerative Ultrasound Wake-Up Receiver With Power Scalability
 Abstract: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 , which is smaller by 77% than that of a conventional ultrasound wake-up receiver at a comparable communication distance and data rate. Autors: Hiroshi Fuketa;Shinichi O’uchi;Takashi Matsukawa; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1027 - 1031 Publisher: IEEE
» A 0.65-V, 500-MHz Integrated Dynamic and Static RAM for Error Tolerant Applications
 Abstract: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. Autors: Amit Kazimirsky;Adam Teman;Noa Edri;Alexander Fish; Appeared in: IEEE Transactions on Very Large Scale Integration Systems Publication date: Sep 2017, volume: 25, issue:9, pages: 2411 - 2418 Publisher: IEEE
» A 0.6V 75nW All-CMOS Temperature Sensor With 1.67m°C/mV Supply Sensitivity
 Abstract: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 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. Autors: Xiaoyang Wang;Po-Han Peter Wang;Yuan Cao;Patrick P. Mercier; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2274 - 2283 Publisher: IEEE
» A 160-GHz Switched Injection-Locked Oscillator for Phase and Amplitude Regenerative Sampling
 Abstract: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- SiGe BiCMOS technology ( 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. Autors: Hatem Ghaleb;Paolo Valerio Testa;Stefan Schumann;Corrado Carta;Frank Ellinger; Appeared in: IEEE Microwave and Wireless Components Letters Publication date: Sep 2017, volume: 27, issue:9, pages: 821 - 823 Publisher: IEEE
» A 2.4-GHz CMOS Common-Gate Combining Power Amplifier With Load Impedance Adaptor
 Abstract: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 mm2 operates at 2.484 GHz with a 3.3 V supply, which is implemented with the 0.18- 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. Autors: Yoonsoo Jin;Songcheol Hong; Appeared in: IEEE Microwave and Wireless Components Letters Publication date: Sep 2017, volume: 27, issue:9, pages: 836 - 838 Publisher: IEEE
» A 2.4-GHz Super-Regenerative Transceiver With Selectivity-Improving Dual Q-Enhancement Architecture and 102- $\mu \text{W}$ All-Digital FLL
 Abstract:A multichannel super-regenerative transceiver with a selectivity-improving dual Q-enhancement architecture and a 102- 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/ bit error rate (BER) and interference selectivity of 32 dB at a 1-Mb/s/10-MHz offset while consumping at the all-digital FLL and 0.93/2.37 nJ/b at receiver/transmitter, respectively. Autors: Seong Joong Kim;DongSoo Lee;Kang-Yoon Lee;Sang-Gug Lee; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3287 - 3298 Publisher: IEEE
» 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
 Abstract: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 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 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. Autors: Joachim Leicht;Yiannos Manoli; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2448 - 2462 Publisher: IEEE
» A 27-Gb/s Time-Interleaved Duobinary Transmitter Achieving 1.44-mW/Gb/s FOM in 65-nm CMOS
 Abstract: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. Autors: Yong Chen;Pui-In Mak;Chirn Chye Boon;Rui P. Martins; Appeared in: IEEE Microwave and Wireless Components Letters Publication date: Sep 2017, volume: 27, issue:9, pages: 839 - 841 Publisher: IEEE
» A 3-RSR Haptic Wearable Device for Rendering Fingertip Contact Forces
 Abstract: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. Autors: Daniele Leonardis;Massimiliano Solazzi;Ilaria Bortone;Antonio Frisoli; Appeared in: IEEE Transactions on Haptics Publication date: Sep 2017, volume: 10, issue:3, pages: 305 - 316 Publisher: IEEE
» 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
 Abstract: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. Autors: 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; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2438 - 2447 Publisher: IEEE
» A 38 pJ/b Optimal Soft-MIMO Detector
 Abstract: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 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. Autors: M. Shabany;R. Doostnejad;M. Mahdavi;P. Glenn Gulak; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1062 - 1066 Publisher: IEEE
» A 40-Gb/s 14-mW CMOS Wireline Receiver
 Abstract: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. Autors: Abishek Manian;Behzad Razavi; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2407 - 2421 Publisher: IEEE
» A 5-GHz WLAN RF CMOS Power Amplifier With a Parallel-Cascoded Configuration and an Active Feedback Linearizer
 Abstract: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- 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. Autors: Seunghoon Kang;Donghyun Baek;Songcheol Hong; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3230 - 3244 Publisher: IEEE
» A 50 Gb/s 190 mW Asymmetric 3-Tap FFE VCSEL Driver
 Abstract: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. Autors: Guido Belfiore;Mahdi Khafaji;Ronny Henker;Frank Ellinger; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2422 - 2429 Publisher: IEEE
» A 5GHz Digital Fractional- $N$ PLL Using a 1-bit Delta–Sigma Frequency-to-Digital Converter in 65 nm CMOS
 Abstract:A highly digital two-stage fractional- phase-locked loop (PLL) architecture utilizing a first-order 1-bit frequency-to-digital converter (FDC) is proposed and implemented in a 65nm CMOS process. Performance of the first-order 1-bit 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 FDC followed by an accumulator that allows us to leverage the TDC-based PLL analysis techniques to study the impact of FDC characteristics on FDC-based fractional- PLL (FDCPLL) performance. Utilizing proposed techniques, a prototype PLL achieves 1 MHz bandwidth, −101.6 dBc/Hz in-band phase noise, and (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- FDCPLL achieves 1MHz bandwidth, −106.1dBc/Hz in-band phase noise, and 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. Autors: Mrunmay Talegaonkar;Tejasvi Anand;Ahmed Elkholy;Amr Elshazly;Romesh Kumar Nandwana;Saurabh Saxena;Brian Young;Woo-Seok Choi;Pavan Kumar Hanumolu; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2306 - 2320 Publisher: IEEE
» A 7.1-mW $K/K_{a}$ -Band Mixer With Configurable Bondwire Resonators in 65-nm CMOS
 Abstract:A low-power (LP) /-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. Autors: Chun-Hsing Li;Chun-Lin Ko;Ming-Ching Kuo;Da-Chiang Chang; Appeared in: IEEE Transactions on Very Large Scale Integration Systems Publication date: Sep 2017, volume: 25, issue:9, pages: 2635 - 2648 Publisher: IEEE
» A 76- to 81-GHz Multi-Channel Radar Transceiver
 Abstract: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. Autors: Takeji Fujibayashi;Yohsuke Takeda;Weihu Wang;Yi-Shin Yeh;Willem Stapelbroek;Seiji Takeuchi;Brian Floyd; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2226 - 2241 Publisher: IEEE
» A 950 nW Analog-Based Data Reduction Chip for Wearable EEG Systems in Epilepsy
 Abstract: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 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. Autors: Saam Iranmanesh;Esther Rodriguez-Villegas; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2362 - 2373 Publisher: IEEE
» A Bayesian Approach to Camouflaged Moving Object Detection
 Abstract: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. Autors: Xiang Zhang;Ce Zhu;Shuai Wang;Yipeng Liu;Mao Ye; Appeared in: IEEE Transactions on Circuits and Systems for Video Technology Publication date: Sep 2017, volume: 27, issue:9, pages: 2001 - 2013 Publisher: IEEE
» A Bilevel Optimization Model for Risk Assessment and Contingency Ranking in Transmission System Reliability Evaluation
 Abstract: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. Autors: Tao Ding;Cheng Li;Chao Yan;Fangxing Li;Zhaohong Bie; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3803 - 3813 Publisher: IEEE
» A Bio-Inspired Analog Gas Sensing Front End
 Abstract: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. Autors: Ping-Chen Huang;Jan M. Rabaey; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2611 - 2623 Publisher: IEEE
» A Blind Adaptive Tuning Algorithm for Reliable and Energy-Efficient Communication in IEEE 802.15.4 Networks
 Abstract:Previous studies have shown that the IEEE 802.15.4 CSMA/CA with default parameter values suffers from a severe unreliability problem, which is undesirable in many wireless sensor network applications. For time-varying and unknown operating conditions, how to autonomously adjust parameters for reliability guarantees with low energy consumption is a significant challenge, especially when the acknowledgement (ACK) mechanism is disabled in order to reduce extra overhead and waiting time in control or alarm applications. In this paper, we propose a lightweight distributed algorithm called Blind ADaptive Access Parameter Tuning (BADAPT) for reliable and energy-efficient communication in IEEE 802.15.4 networks without using the ACK mechanism. Unlike previous adaptive algorithms that require a costly ACK to notify a sensor node whether a packet is successfully transmitted or not, the BADAPT allows sensor nodes to merely use the locally measured busy channel probabilities to estimate individual reliability under unknown operating conditions. Simulation results show that the BADAPT is effective both in stationary and dynamic scenarios. Autors: Yijin Zhang;Yuanda Zhou;Le Gao;Yuwen Qian;Jun Li;Feng Shu; Appeared in: IEEE Transactions on Vehicular Technology Publication date: Sep 2017, volume: 66, issue:9, pages: 8605 - 8609 Publisher: IEEE
» A Bridgeless Controlled Rectifier for Single Split-Phase Systems
 Abstract:An unidirectional single-phase three-wire rectifier is proposed in this paper. Such topology is composed of a noncontrolled leg, two controlled legs, and a capacitor bank. A suitable model, pulse-width modulation, and control strategies of the system are proposed as well. The control strategy includes the synchronization method, in which it imposes the grid currents with the same phase angle of the voltages generated by the rectifier. This method ensures sinusoidal grid currents and mitigates the zero-crossover distortions normally caused by the use of diodes. A comprehensive comparison with two conventional configurations is also presented in this paper. Simulation and experimental results are also presented for validation purposes. Autors: Nustenil Segundo de Moraes Lima Marinus;Euzeli Cipriano dos Santos;Cursino Brandão Jacobina;Nady Rocha;Nayara Brandão de Freitas; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4708 - 4717 Publisher: IEEE
» A Broadband Near-Field UHF RFID Reader Antenna With Low Far-Field Gain
 Abstract: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 mm mm. Autors: Yuan Yao;Yishan Liang;Junsheng Yu;Xiaodong Chen; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4869 - 4874 Publisher: IEEE
» A Butterfly-Based Direct Integral-Equation Solver Using Hierarchical LU Factorization for Analyzing Scattering From Electrically Large Conducting Objects
 Abstract: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 and , 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. Autors: Han Guo;Yang Liu;Jun Hu;Eric Michielssen; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4742 - 4750 Publisher: IEEE
» A Cantilever Vibrational Generator Based on an Fe–Co Beam
 Abstract: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 rms ( m/), a 6.72 mW time average output power is obtained for operating frequencies around 60 Hz. Autors: Mauro Zucca;Arash Hadadian;Fausto Fiorillo;Mario Chiampi; Appeared in: IEEE Transactions on Magnetics Publication date: Sep 2017, volume: 53, issue:9, pages: 1 - 7 Publisher: IEEE
» A Capacitor-DAC-Based Technique For Pre-Emphasis-Enabled Multilevel Transmitters
 Abstract: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. Autors: Boyu Hu;Yuan Du;Rulin Huang;Jeffrey Lee;Young-Kai Chen;Mau-Chung Frank Chang; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1012 - 1016 Publisher: IEEE
» A Case for Nonconvex Distributed Optimization in Large-Scale Power Systems
 Abstract: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. Autors: Junyao Guo;Gabriela Hug;Ozan K. Tonguz; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3842 - 3851 Publisher: IEEE
» A Case Study in User Support for Managing OpenSim Based Multi User Learning Environments
 Abstract:Immersive 3D Multi User Learning Environments (MULE) have shown sufficient success to warrant their consideration as a mainstream educational paradigm. These are based on 3D Multi User Virtual Environment platforms (MUVE), and although they have been used for various innovative educational projects their complex permission systems and large numbers of functions can make their management potentially challenging. It follows that an inadequately managed MULE can be ineffective with respect to intended learning outcomes. The purpose of this research was to determine how management challenges manifest themselves and how to support educators in learning and applying MULE management skills. We utilized the popular OpenSim platform for this study. First, a survey of the need for user support () is described. Next, the design and evaluation of a guidance tool using graph topologic visualization of OpenSim functions is presented ( ). The tool is further evaluated in the delivery of a course module. The analysis and user feedback indicated that the tool provides accurate information and helpful support for MULE management. As the final phase of the research, training environments were developed for both basic and advanced OpenSim MULE management. Evaluations of their usability and perceived educational value were carried out with participants ( ); the outcomes suggest that training for advanced MULE management is more useful for a- l users, without requiring more time or effort, regardless of the degree of complexity of the MULE being designed. Autors: Indika Perera;Alan Miller;Colin Allison; Appeared in: IEEE Transactions on Learning Technologies Publication date: Sep 2017, volume: 10, issue:3, pages: 342 - 354 Publisher: IEEE
» A Centralized Optimization Solution for Application Layer Multicast Tree
 Abstract: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. Autors: Xinchang Zhang;Lu Wang;Ye Li;Meng Sun; Appeared in: IEEE Transactions on Network and Service Management Publication date: Sep 2017, volume: 14, issue:3, pages: 771 - 785 Publisher: IEEE
» A Class of Distance-Optimal Binary Linear Codes With Flexible Parameters
 Abstract: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 , dimension , and minimum distance , where and is an arbitrary integer with . The variable provides flexible tradeoff between the code length and minimal distance. We determine the weight distributions of all the generated binary linear codes and, most notably, mathematically prove that all these codes are distance-optimal with respect to the Griesmer bound. Autors: Deng Tang;Cuiling Fan; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 1893 - 1896 Publisher: IEEE
» A CMOS Seawater Salinity to Digital Converter for IoT Applications of Fish Farms
 Abstract: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. Autors: Cheng-Ta Chiang; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2591 - 2597 Publisher: IEEE
» A Combined Approach for Real-Time Data Compression in Wireless Body Sensor Networks
 Abstract: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. Autors: Giada Giorgi; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 6129 - 6135 Publisher: IEEE
» A Compact SISL Balun Using Compensated Interdigital Capacitor
 Abstract: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 is achieved. Autors: Yongqiang Wang;Kaixue Ma;Shouxian Mou; Appeared in: IEEE Microwave and Wireless Components Letters Publication date: Sep 2017, volume: 27, issue:9, pages: 797 - 799 Publisher: IEEE
» A Compact-Area Low-VDDmin 6T SRAM With Improvement in Cell Stability, Read Speed, and Write Margin Using a Dual-Split-Control-Assist Scheme
 Abstract: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 () 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 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. Autors: Meng-Fan Chang;Chien-Fu Chen;Ting-Hao Chang;Chi-Chang Shuai;Yen-Yao Wang;Yi-Ju Chen;Hiroyuki Yamauchi; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2498 - 2514 Publisher: IEEE
» A Comprehensive Comparison of Multiparty Secure Additions with Differential Privacy
 Abstract: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. Autors: Slawomir Goryczka;Li Xiong; Appeared in: IEEE Transactions on Dependable and Secure Computing Publication date: Sep 2017, volume: 14, issue:5, pages: 463 - 477 Publisher: IEEE
» A Compressed Sensing Based Decomposition of Electrodermal Activity Signals
 Abstract: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. Autors: Swayambhoo Jain;Urvashi Oswal;Kevin Shuai Xu;Brian Eriksson;Jarvis Haupt; Appeared in: IEEE Transactions on Biomedical Engineering Publication date: Sep 2017, volume: 64, issue:9, pages: 2142 - 2151 Publisher: IEEE
» A Compulsator Driven Reluctance Coilgun-Type Electromagnetic Launcher
 Abstract: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. Autors: Bofeng Zhu;Junyong Lu;Jie Wang;Shicheng Xiong; Appeared in: IEEE Transactions on Plasma Science Publication date: Sep 2017, volume: 45, issue:9, pages: 2511 - 2518 Publisher: IEEE
» A Control Method for Bridgeless Cuk/Sepic PFC Rectifier to Achieve Power Decoupling
 Abstract: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. Autors: Yonglu Liu;Yao Sun;Mei Su; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7272 - 7276 Publisher: IEEE
» A Convex Combination of NLMS and ZA-NLMS for Identifying Systems With Variable Sparsity
 Abstract: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. Autors: Bijit K. Das;G. Vinay Chakravarthi;Mrityunjoy Chakraborty; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1112 - 1116 Publisher: IEEE
» A Convex Primal Formulation for Convex Hull Pricing
 Abstract: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. Autors: Bowen Hua;Ross Baldick; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3814 - 3823 Publisher: IEEE
» A Cooperative Multihop Transmission Scheme for Two-Way Amplify-and-Forward Relay Networks
 Abstract:In this paper, we present a cooperative multihop transmission scheme for two-way amplify-and-forward (AF) relay networks. Based on a symbol error probability (SEP) analysis and using geographic information, we derive the maximum one-hop distance for a networking node under a given SEP and develop a next-hopping-node selection scheme. With these results, we then propose a routing protocol based on a greedy algorithm to realize the transmission scheme, where a routing path consisting of a number of independent two-way AF relaying procedures is built to connect the two sources. As compared to a previous related work, the proposed approach removes the utilization limitation and improves the routing efficiency. Computer simulation results also show that it provides a higher probability of successfully building a routing path with close effective throughput for most cases of interest. Autors: Chin-Liang Wang;Ting-Nan Cho;Tsung-Hsien Tsai;Min-Chau Jan; Appeared in: IEEE Transactions on Vehicular Technology Publication date: Sep 2017, volume: 66, issue:9, pages: 8569 - 8574 Publisher: IEEE
» A Copula-Based Trend-Renewal Process Model for Analysis of Repairable Systems With Multitype Failures
 Abstract: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. Autors: Qingyu Yang;Yili Hong;Nailong Zhang;Jie Li; Appeared in: IEEE Transactions on Reliability Publication date: Sep 2017, volume: 66, issue:3, pages: 590 - 602 Publisher: IEEE
» A Data-Driven and Optimal Bus Scheduling Model With Time-Dependent Traffic and Demand
 Abstract: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. Autors: Yuan Wang;Dongxiang Zhang;Lu Hu;Yang Yang;Loo Hay Lee; Appeared in: IEEE Transactions on Intelligent Transportation Systems Publication date: Sep 2017, volume: 18, issue:9, pages: 2443 - 2452 Publisher: IEEE
» A Dataset and Benchmarks for Segmentation and Recognition of Gestures in Robotic Surgery
 Abstract: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. Autors: Narges Ahmidi;Lingling Tao;Shahin Sefati;Yixin Gao;Colin Lea;Benjamín Béjar Haro;Luca Zappella;Sanjeev Khudanpur;René Vidal;Gregory D. Hager; Appeared in: IEEE Transactions on Biomedical Engineering Publication date: Sep 2017, volume: 64, issue:9, pages: 2025 - 2041 Publisher: IEEE
» A Decentralized Power Management Strategy for Hybrid Energy Storage System With Autonomous Bus Voltage Restoration and State-of-Charge Recovery
 Abstract: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. Autors: Qianwen Xu;Jianfang Xiao;Xiaolei Hu;Peng Wang;Meng Yeong Lee; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7098 - 7108 Publisher: IEEE
» A Decoupled Adaptive Noise Detection Based Control Approach for a Grid Supportive SPV System
 Abstract:A grid supportive two-stage three-phase four-wire solar photovoltaic (SPV) system is presented in this paper, wherein a boost converter is used as a first stage to serve the function of maximum power point tracking (MPPT) and a four-leg voltage source converter (VSC) is used to feed the extracted SPV energy, along with supporting distribution system for improvement in the power quality. Unlike conventional SPV inverters, the proposed solar energy conversion system provides extra functionalities such as balancing of grid currents, reactive power compensation, mitigation of harmonics, and neutral current elimination in grid side neutral conductor. An extra feed-forward term is added in the control loop to provide fast dynamic responses. The PV array voltage is continuously adjusted using a boost converter to achieve MPPT. A control approach employing decoupled adaptive noise detection (DAND) algorithm is used for controlling the four-leg grid-tied VSC. The DAND algorithm is a simple approach using two multipliers, one integrator, and one summer per phase for detection of useful component of load current. The proposed control algorithm gives features such as simple structure, fast convergence, frequency adaptive detection, and good steady-state performance. The grid currents are found adhering to an IEEE-519 standard, even under nonlinear and unbalanced loads at common point of interconnection. Autors: Bhim Singh;Chinmay Jain; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4894 - 4902 Publisher: IEEE
» A Descriptive Survey of Technical Editors
 Abstract: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. Autors: Melinda L. Kreth;Elizabeth Bowen; Appeared in: IEEE Transactions on Professional Communication Publication date: Sep 2017, volume: 60, issue:3, pages: 238 - 255 Publisher: IEEE
» A Distributed Deployment Algorithm of Process Fragments With Uncertain Traffic Matrix
 Abstract: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 -optimal deployment solution to deal with the mentioned problems, where 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. Autors: Shoulu Hou;Shuai Zhao;Bo Cheng;Shiping Chen;Yongyang Cheng;Junliang Chen; Appeared in: IEEE Transactions on Network and Service Management Publication date: Sep 2017, volume: 14, issue:3, pages: 690 - 701 Publisher: IEEE
» A Double-T-Type Compensation Network and Its Tuning Method for IPT System
 Abstract:This paper presents a new design strategy for an S-LCC-type compensation network in inductive power transfer (IPT) systems to achieve constant voltage output. It was found that four resonant elements (three capacitors and one inductor) can compose two symmetric T-type resonant tanks, which is well-known for its impedance transformation characteristic and reciprocity between voltage source and current source. A simplified analytical technique is used to calculate the voltage gain and parameters for each resonant element. Besides, the proposed tuning method for an S-LCC network has negligible response to high-order harmonics, allowing wide range of output voltage regulation and easy implementation of zero voltage switching. To aid designers in practical design and circuit debugging, sensitivity of one critical resonant element is analyzed. To verify the analysis, a 165 W prototype with 50 mm gap and fixed voltage transfer ratio was fabricated and tested. An overall 90% efficiency was achieved from dc 70 V input to dc 30 V output. Autors: Yijie Wang;Guangyao Shi;Yousu Yao;Jose Marcos Alonso;Guo Weifeng;Xiaosheng Liu;Dianguo Xu; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4757 - 4767 Publisher: IEEE
» A Dual-Imaging Speed-Enhanced CMOS Image Sensor for Real-Time Edge Image Extraction
 Abstract: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 () between a chosen pixel and the previous pixel. If a chosen pixel is at a boundary of an object with a large 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 , 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- 1P4M CMOS image sensor process with a 4.9- 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 , and 0.34 /step. Autors: Hyeon-June Kim;Sun-Il Hwang;Jae-Hyun Chung;Jong-Ho Park;Seung-Tak Ryu; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2488 - 2497 Publisher: IEEE
» A Dual-Mode Magnetic–Acoustic System for Monitoring Fluid Intake Behavior in Animals
 Abstract: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. Autors: Saman Sargolzaei;Hassan Elahi;Alan Sokoloff;Maysam Ghovanloo; Appeared in: IEEE Transactions on Biomedical Engineering Publication date: Sep 2017, volume: 64, issue:9, pages: 2090 - 2097 Publisher: IEEE
» A Dual-Polarized 1-D Tightly Coupled Dipole Array Antenna
 Abstract: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 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 plane >61° over the operating frequency band for both polarizations, consistent with the simulation result. Autors: Hakjune Lee;Sangwook Nam; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4511 - 4518 Publisher: IEEE
» A Fair Power Allocation Approach to NOMA in Multiuser SISO Systems
 Abstract:A nonorthogonal multiple access (NOMA) approach that always outperforms orthogonal multiple access (OMA) called Fair-NOMA is introduced. In Fair-NOMA, each mobile user is allocated its share of the transmit power such that its capacity is always greater than or equal to the capacity that can be achieved using OMA. For any slow-fading channel gains of the two users, the set of possible power allocation coefficients is derived. For the infimum and supremum of this set, the individual capacity gains and the sum-rate capacity gain are derived. It is shown that the ergodic sum-rate capacity gain approaches 1 b/s/Hz when the transmit power increases for the case when pairing two random users with independent identically distributed channel gains. The outage probability of this approach is derived and shown to be better than OMA. The Fair-NOMA approach is applied to the case of pairing a near base-station user and a cell-edge user and the ergodic capacity gap is derived as a function of total number of users in the cell at high SNR. This is then compared to the conventional case of fixed-power NOMA with user pairing. Finally, Fair-NOMA is extended to users and it is proven that the capacity can always be improved for each user, while using less than the total transmit power required to achieve OMA capacities per user. Autors: José Armando Oviedo;Hamid R. Sadjadpour; Appeared in: IEEE Transactions on Vehicular Technology Publication date: Sep 2017, volume: 66, issue:9, pages: 7974 - 7985 Publisher: IEEE
» A Fast Algorithm for Analysis of Molecular Communication in Artificial Synapse
 Abstract:In this paper, we analyze molecular communications (MCs) in a proposed artificial synapse (AS), whose main difference from biological synapses (BSs) is that it is closed, i.e., transmitter molecules cannot diffuse out from AS. Such a setup has both advantages and disadvantages. Besides higher structural stability, being closed, AS never runs out of transmitters. Thus, MC in AS is disconnected from outer environment, which is very desirable for possible intra-body applications. On the other hand, clearance of transmitters from AS has to be achieved by transporter molecules on the presynaptic membrane of AS. Except from these differences, rest of AS content is taken to be similar to that of a glutamatergic BS. Furthermore, in place of commonly used Monte Carlo-based random walk experiments, we derive a deterministic algorithm that attacks for expected values of desired parameters such as evolution of receptor states. To assess validity of our algorithm, we compare its results with average results of an ensemble of Monte Carlo experiments, which shows near exact match. Moreover, our approach requires significantly less amount of computation compared with Monte Carlo approach, making it useful for parameter space exploration necessary for optimization in design of possible MC devices, including but not limited to AS. Results of our algorithm are presented in case of single quantal release only, and they support that MC in closed AS with elevated uptake has similar properties to that in BS. In particular, similar to glutamatergic BSs, the quantal size and the density of receptors are found to be main sources of synaptic plasticity. On the other hand, the proposed model of AS is found to have slower decaying transients of receptor states than BSs, especially desensitized ones, which is due to prolonged clearance of transmitters from AS. Autors: Bilgesu A. Bilgin;Ozgur B. Akan; Appeared in: IEEE Transactions on NanoBioscience Publication date: Sep 2017, volume: 16, issue:6, pages: 408 - 417 Publisher: IEEE
» A Fast and Low-Complexity Operator for the Computation of the Arctangent of a Complex Number
 Abstract: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. Autors: Vicente Torres;Javier Valls; Appeared in: IEEE Transactions on Very Large Scale Integration Systems Publication date: Sep 2017, volume: 25, issue:9, pages: 2663 - 2667 Publisher: IEEE
» A Fast Marching-on-in-Degree Solution for Analysis of Conductors Coated With Thin Dispersive Dielectric
 Abstract: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. Autors: Z. He;R. S. Chen; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4751 - 4758 Publisher: IEEE
» A Fixed-Beam Leaky-Wave Cavity-Backed Slot Antenna Manufactured by Bulk Silicon MEMS Technology
 Abstract: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. Autors: Peiqin Liu;Yue Li;Zhijun Zhang;Shaodong Wang;Zhenghe Feng; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4399 - 4405 Publisher: IEEE
» A Flash-Based Non-Uniform Sampling ADC With Hybrid Quantization Enabling Digital Anti-Aliasing Filter
 Abstract: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. Autors: Tzu-Fan Wu;Cheng-Ru Ho;Mike Shuo-Wei Chen; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2335 - 2349 Publisher: IEEE
» A Flexible CO-OFDM Using Reconfigurable Multi-Precision FFT
 Abstract: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. Autors: Hatam Abdoli;Hooman Nikmehr; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 1997 - 2000 Publisher: IEEE
» A Framework for Educational Technologies that Support Representational Competencies
 Abstract:Visual representations are ubiquitous in STEM disciplines. Yet, students’ difficulties in learning with visual representations are well documented. Therefore, to succeed in STEM, students need representational competencies—the ability to use visual representations for problem solving and learning. Educational technologies that support students’ acquisition of representational competencies can significantly enhance their success in STEM disciplines. Current design frameworks for educational technologies do not offer sufficient guidance to develop supports for representational competencies. This paper presents a new design framework that describes an iterative, step-by-step approach for the design of educational technologies that support representational competencies (SUREC) in a way that aligns with the demands specific to the target discipline. The paper illustrates how this framework was used to inform the design of an intelligent tutoring system for undergraduate chemistry. An evaluation study suggests that the SUREC framework yielded an effective educational technology that enhances students’ learning of content knowledge. Autors: Martina Angela Rau; Appeared in: IEEE Transactions on Learning Technologies Publication date: Sep 2017, volume: 10, issue:3, pages: 290 - 305 Publisher: IEEE
» A Fully Integrated Battery-Powered System-on-Chip in 40-nm CMOS for Closed-Loop Control of Insect-Scale Pico-Aerial Vehicle
 Abstract: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. Autors: 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; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2374 - 2387 Publisher: IEEE
» A Fully Integrated Dual-Mode CMOS Power Amplifier With an Autotransformer-Based Parallel Combining Transformer
 Abstract: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. Autors: Hyunjin Ahn;Seungjun Baek;Ilku Nam;Deokgi An;Jae Kyung Lee;Minsu Jeong;Bo-Eun Kim;Jaehyouk Choi;Ockgoo Lee; Appeared in: IEEE Microwave and Wireless Components Letters Publication date: Sep 2017, volume: 27, issue:9, pages: 833 - 835 Publisher: IEEE
» A Fuzzy Error Characterization Approach for Crack Depth Profile Estimation in Metallic Structures Through ACFM Data
 Abstract: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. Autors: Danial Katoozian;Reza P. R. Hasanzadeh; Appeared in: IEEE Transactions on Magnetics Publication date: Sep 2017, volume: 53, issue:9, pages: 1 - 10 Publisher: IEEE
» A Game Theoretic Approach to Network Reliability Assessment
 Abstract: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. Autors: Xiaoge Zhang;Sankaran Mahadevan; Appeared in: IEEE Transactions on Reliability Publication date: Sep 2017, volume: 66, issue:3, pages: 875 - 892 Publisher: IEEE
» A Gap Waveguide-Fed Wideband Patch Antenna Array for 60-GHz Applications
 Abstract: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 -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. Autors: Davoud Zarifi;Ali Farahbakhsh;Ashraf Uz Zaman; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4875 - 4879 Publisher: IEEE
» A GBSAR Operating in Monostatic and Bistatic Modalities for Retrieving the Displacement Vector
 Abstract: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. Autors: Massimiliano Pieraccini;Lapo Miccinesi;Neda Rojhani; Appeared in: IEEE Geoscience and Remote Sensing Letters Publication date: Sep 2017, volume: 14, issue:9, pages: 1494 - 1498 Publisher: IEEE
» A Gene–Protein–miRNA Electronic Oscillator
 Abstract: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. Autors: Sadia Alam;S. M. Rezaul Hasan; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1007 - 1011 Publisher: IEEE
» A General Analytical Three-Phase Induction Machine Core Loss Model in the Arbitrary Reference Frame
 Abstract:An analytical three-phase induction machine model is proposed, derived, and validated in this paper. This model is capable for arbitrary qd0-frame analysis and core loss estimation at both line-fed and inverter-fed situations. Detailed model-based machine copper and core loss estimations are presented. A simulation verification of the model consistency is given under a changing load profile in MATLAB/Simulink. Then, the model is verified comprehensively using three induction machines (1.5 HP, 3 HP, and 10 HP), where the model is proved to be scalable, and to provide excellent machine loss estimation in line-fed situation and inverter-fed situation with machine input line filters, as well as in the flux-weakening region. Finally, a series of sensitivity tests of the model parameters are performed and the effects of the parameters on the machine losses are discussed. It is believed that the proposed model will be beneficial for various qd0-frame model-based research works of three-phase induction machines. Autors: Yiqi Liu;Ali M. Bazzi; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4210 - 4220 Publisher: IEEE
» A General Dynamic Scaling Based Control Redesign to Handle Input Unmodeled Dynamics in Uncertain Nonlinear Systems
 Abstract: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. Autors: P. Krishnamurthy;F. Khorrami; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4719 - 4726 Publisher: IEEE
» A General Expression to Determine the Rotor Field Current of Synchronous Machines
 Abstract: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. Autors: Federico Milano; Appeared in: IEEE Transactions on Energy Conversion Publication date: Sep 2017, volume: 32, issue:3, pages: 1099 - 1101 Publisher: IEEE
» A Genetic-Algorithm-Optimized Fractal Model to Predict the Constriction Resistance From Surface Roughness Measurements
 Abstract: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. Autors: Francesca Capelli;Jordi-Roger Riba;Elisa Rupérez;Josep Sanllehí; Appeared in: IEEE Transactions on Instrumentation and Measurement Publication date: Sep 2017, volume: 66, issue:9, pages: 2437 - 2447 Publisher: IEEE
» A Geometry-Based Channel Model to Simulate an Averaged-Power-Delay Profile
 Abstract: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. Autors: Thomas Jost;Wei Wang;Michael Walter; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4925 - 4930 Publisher: IEEE
» A GPU-Accelerated Fourth-Order Runge–Kutta in the Interaction Picture Method for the Simulation of Nonlinear Signal Propagation in Multimode Fibers
 Abstract: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. Autors: Marius Brehler;Malte Schirwon;Dominik Göddeke;Peter M. Krummrich; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:17, pages: 3622 - 3628 Publisher: IEEE
» A Handy Dandy Doherty PA: A Linear Doherty Power Amplifier for Mobile Handset Application
 Abstract: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. Autors: Yunsung Cho;Daehyun Kang;Kyunghoon Moon;Daechul Jeong;Bumman Kim; Appeared in: IEEE Microwave Magazine Publication date: Sep 2017, volume: 18, issue:6, pages: 110 - 124 Publisher: IEEE

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