Electrical and Electronics Engineering publications abstract of: 07-2017 sorted by title, page: 8

» High Breakdown Voltage (−201) $\beta $ -Ga2O3 Schottky Rectifiers
Abstract:
-Ga2O3 Schottky barrier diodes were fabricated in a vertical geometry structure consisting of Ni/Au rectifying contacts without edge termination on Si-doped epitaxial layers (, cm on Sn-doped bulk Ga2O3 substrates with full-area Ti/Au back Ohmic contacts. The reverse breakdown voltage, , was a function of rectifying contact area, ranging from 1600 V at cm2 (20- diameter) to ~250 V at cm (0.53-mm diameter). The current density near breakdown was not strongly dependent on contact circumference but did scale with contact area, indicating that the bulk current contribution was dominant. The lowest ON-state resistance, , was 1.6 cm2 for the largest diode and 25 cm2 for the 1600-V rectifier, leading to a Baliga figure-of-merit ( for the latter of approximately 102.4 MWcm. The ON-OFF ratio was measured at a forward voltage of 1.3 V and ranged from to for reverse biases from −5 to −40 V and showed only a small dependence on temperature in the range from 25 °C to 100 °C.
Autors: Jiancheng Yang;Shihyun Ahn;F. Ren;S. J. Pearton;Soohwan Jang;A. Kuramata;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2017, volume: 38, issue:7, pages: 906 - 909
Publisher: IEEE
 
» High Electron Mobility Transistors With Al0.65Ga0.35N Channel Layers on Thick AlN/Sapphire Templates
Abstract:
We report Al0.85 Ga0.15 N/Al0.65 Ga0.35N high-electron mobility transistors on low-defect AlN buffer layers over basal plane sapphire substrates. A new epilayer design consisting of a doped barrier layer yielded sheet resistivity values as low as . Devices with the source–drain spacing of and a gate length of 1.8 exhibited peak drain–currents as high as 250 mA/mm at a gate bias of +4 V. We also show that the 3- thick low-defect AlN buffer layers over sapphire to provide sufficient thermal conduction which enables stable device operation up to at least 40 V at 250 mA/mm with no current droop.
Autors: Sakib Muhtadi;Seong Mo Hwang;Antwon Coleman;Fatima Asif;Grigory Simin;MVS Chandrashekhar;Asif Khan;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2017, volume: 38, issue:7, pages: 914 - 917
Publisher: IEEE
 
» High Energy All-Fiber Tm-Doped Femtosecond Soliton Laser Mode-Locked by Nonlinear Polarization Rotation
Abstract:
A high-energy thulium-doped all-fiber soliton laser passively mode-locked by nonlinear polarization rotation (NPR) technology is presented, generating 350 fs pulses with spectral width of 11.5 nm at 1890 nm wavelength. Kelly sidebands of the soliton spectrum are well suppressed due to the NPR effect in the fiber laser. The average output power reaches 90 mW, corresponding to the pulse energy up to 7.8 nJ and the pulse peak power of 22.3 kW, leading to the higher order soliton generation. This has been testified by the relationship between the soliton period and the cavity length. Thus, the laser can deliver high-energy ultrashort soliton pulses while the pulse shape is close to one of the fundamental solitons. We believe that this represents one of the best observations of short pulse duration as well as high pulse power coexisting in Tm-doped soliton fiber lasers.
Autors: Caixia Gao;Zhiqiang Wang;Hao Luo;Li Zhan;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 2988 - 2993
Publisher: IEEE
 
» High Gain Dual-Band Beam-Steering Transmit Array for Satcom Terminals at Ka-Band
Abstract:
Transmit array design is more challenging for dual-band operation than for single band, due to the independent 360° phase wrapping jumps needed at each band when large electrical length compensation is involved. This happens when aiming at large gains, typically above 25 dBi with beam scanning and . No such designs have been reported in the literature. A general method is presented here to reduce the complexity of dual-band transmit array design, valid for arbitrarily large phase error compensation and any band ratio, using a finite number of different unit cells. The procedure is demonstrated for two offset transmit array implementations operating in circular polarization at 20 GHz(Rx) and 30 GHz(Tx) for Ka-band satellite-on-the-move terminals with mechanical beam-steering. An appropriate set of 30 dual-band unit cells is developed with transmission coefficient greater than −0.9 dB. The full-size transmit array is characterized by full-wave simulation enabling elevation beam scanning over 0°–50° with gains reaching 26 dBi at 20 GHz and 29 dBi at 30 GHz. A smaller prototype was fabricated and measured, showing a measured gain of 24 dBi at 20 GHz and 27 dBi at 30 GHz. In both cases, the beam pointing direction is coincident over the two frequency bands, and thus confirming the proposed design procedure.
Autors: Sérgio A. Matos;Eduardo B. Lima;Joana S. Silva;Jorge R. Costa;Carlos A. Fernandes;Nelson J. G. Fonseca;Juan R. Mosig;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2017, volume: 65, issue:7, pages: 3528 - 3539
Publisher: IEEE
 
» High Mobility Amorphous Indium-Gallium-Zinc-Oxide Thin-Film Transistor by Aluminum Oxide Passivation Layer
Abstract:
This letter demonstrates a high-mobility amorphous indium–gallium–zinc oxide (a-IGZO) thin-film transistor (TFT) with aluminum oxide (Al2O3) passivation layer by radio frequency (RF) magnetron sputtering and copper (Cu) source/drain electrodes. The fabricated a-IGZO TFT exhibited 20 times higher saturation mobility (142.0 cm2/Vs) than the reference device without Al2O3 passivation layer. The generation of metallic indium at the back-channel interface caused by the bombardment of the sputtered Al2O3 is the main principle for the remarkable enhancement of saturation mobility. Furthermore, the a-IGZO TFT maintains high mobility and air-ambient-stable characteristics up to four months in ambient conditions.
Autors: Shiben Hu;Kuankuan Lu;Honglong Ning;Zeke Zheng;Hongke Zhang;Zhiqiang Fang;Rihui Yao;Miao Xu;Lei Wang;Linfeng Lan;Junbiao Peng;Xubing Lu;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2017, volume: 38, issue:7, pages: 879 - 882
Publisher: IEEE
 
» High Performance Silicon Carbide Power Block for Industry Applications
Abstract:
Silicone carbide (SiC) power devices have been optimized in performance over the past decade. However, wide industry adoption of SiC technology still faces challenges from system design perspective. This paper demonstrates an integrated air-cooled three-phase SiC power block for industry applications. The key design aspects, such as high performance gate driver, low parasitic layout, optimized thermal management, as well as flexible control platform are addressed. Experimental results are provided to demonstrate the superior performance of the design.
Autors: Xu She;Rajib Datta;Maja Harfman Todorovic;Gary Mandrusiak;Jian Dai;Tony Frangieh;Philip Cioffi;Brian Rowden;Frank Mueller;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3738 - 3747
Publisher: IEEE
 
» High Sensitivity Ammonia Gas Sensor Based on a Silica-Gel-Coated Microfiber Coupler
Abstract:
In this paper, a high-sensitivity ammonia gas sensor is proposed based on a silica-gel-coated microfiber coupler (MFC). The MFC structure is formed by the two tapered fibers with 3 μm waist diameter each, which were fabricated by using a customized microheater brushing technique. Silica gel coating was prepared by a sol-gel technique and applied on the surface of the MFC as a thin layer. The spectral characteristics of the proposed sensor were studied under various ammonia gas concentrations. The experimental results show that the coating thickness strongly affected the sensitivity of the MFC-based sensor to ammonia gas concentration. For the sensor with a 90 nm silica gel coating thickness, the highest measurement sensitivity is 2.23 nm/ppm for ammonia gas concentration, and the resolution is as good as 5 ppb, while the measured response and recovery times are ~50 and 35 s, respectively. Finally, it is demonstrated that the proposed sensor offers good repeatability and selectivity to ammonia gas.
Autors: Lei Sun;Yuliya Semenova;Qiang Wu;Dejun Liu;Jinhui Yuan;Tao Ma;Xinzhu Sang;Binbin Yan;Kuiru Wang;Chongxiu Yu;Gerald Farrell;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 2864 - 2870
Publisher: IEEE
 
» High-Accuracy Localization Platform Using Asynchronous Time Difference of Arrival Technology
Abstract:
Despite extensive research efforts on ranging and localization modeling and simulation, research on practical implementations is limited. For the first time, a complete prototype based on asynchronous time difference of arrival (A-TDOA) technique is implemented in hardware. The A-TDOA technique requires neither clock synchronization between a target and anchor nodes nor wired infrastructure among anchor nodes, both of which are necessary for time of arrival and TDOA systems, respectively. All subsystems, including transmitter, receiver, antenna, and baseband processing unit, are developed from scratch and undergone significant updates for improved reliability. The implemented system has been extensively tested in an outdoor and indoor line of sight radio environments, and the accuracies obtained are 20.7 and 15.2 cm in 8 m × 8 m and 6 m × 6 m areas, respectively. In nonline of sight indoor environment, the achieved accuracy is 21.3 cm in 5 m × 5 m area. The comparison with the literature published to date proves the excellent quality of these results. To better understand the localization accuracy, the error sources due to thermal noise, hardware limitation, and radio propagation channel are identified and investigated. Mitigation methods are proposed to reduce errors. The implemented prototype supports many unique applications including cargo tracking, tourist guiding, emergency evacuation, and so on.
Autors: Shuai He;Xiaodai Dong;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1728 - 1742
Publisher: IEEE
 
» High-Current Drivability Fibonacci Charge Pump With Connect–Point–Shift Enhancement
Abstract:
A switched-capacitor dc–dc voltage regulator that converts an input of 2.4–3.6 V to an output of 30 V has been designed to power display driver integrated circuits. A novel Fibonacci structure, named connect–point–shift, is proposed to improve the current drivability, which increases the minimum current drivability from 0.16 to 0.274 mA. This scheme saves the chip size by approximately 40% while providing equal current drivability as the traditional one. The power efficiency has been improved by 1%–7%, and a peak efficiency of 83.4% has been achieved. The adaptive-conversion-ratio has been adopted for ripple and efficiency improvement. A pulse skip regulator and a linear regulator are utilized to keep the output terminal of the charge pump stable at around 30 V. Their ripple, efficiency, load regulation, and line regulation are compared for further optimization. Theories of Degenerate State and state-space averaging are applied to validate the performance enhancement. This scheme has been fabricated and validated by a 0.11- 1.5 V/6 V/30 V process.
Autors: Hesheng Lin;Wing Chun Chan;Wai Kwong Lee;Zhirong Chen;Mansun Chan;Min Zhang;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jul 2017, volume: 25, issue:7, pages: 2164 - 2173
Publisher: IEEE
 
» High-Efficiency Impedance Control Network Resonant DC–DC Converter With Optimized Startup Control
Abstract:
This paper presents an improved efficiency impedance control network (ICN) resonant dc–dc converter that maintains zero-voltage switching (ZVS) and near-zero-current switching (ZCS) across wide ranges in input and output voltages and output power. The improvement in efficiency in this burst mode operated converter is achieved through an optimized startup control that minimizes its startup transient and helps the converter maintain ZVS and near-ZCS operation, even during the startup for each burst cycle. This optimization of startup is made possible by a new accurate time domain model for the ICN converter waveforms that helps reduce the number of non-ZVS transitions by 75%. A prototype 200 W, 500 kHz ICN resonant converter designed to operate over an input voltage range of 25–40 V and output voltage range of 250–400 V is built and tested. The prototype ICN converter achieves a peak efficiency of 97.2% and maintains greater than 96.2% full power efficiency at 250 V output voltage across the nearly 2:1 input voltage range, and maintains full power efficiency above 94.6% across its full input and output voltage range. The converter also maintains efficiency above 93.6% over a 10:1 output power range across its full input and output voltage range.
Autors: Jie Lu;Khurram K. Afridi;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3880 - 3889
Publisher: IEEE
 
» High-Efficiency Waveguide Optical Amplifiers and Lasers via FS-Laser Induced Local Modification of the Glass Composition
Abstract:
FS-laser irradiation at high repetition pulse rate enables producing high-performance passive waveguides in different glasses through the local modification of the glass composition. In this paper, we show that this mechanism can similarly be used to produce high-performance waveguide amplifiers and lasers. Furthermore, we show the feasibility of producing active waveguides with different optical gains in the same phosphate glass sample by changing the laser writing parameters. The lanthanides present in the glass composition (Er3+, Yb3+ , and La3+, the refractive index carrying element) experience similar local concentration changes upon fs-laser writing, enabling to determine the concentration of La3+ and thus the refractive index contrast of the guiding region by measuring its absorption at 1534 nm. The produced waveguide lasers show slope efficiencies (respect to the absorbed pump power) above 38%, which could reach up to 42% by further optimization of the waveguide laser cavity configuration. The active waveguides produced are thermally stable for temperatures up to at least 450 °C.
Autors: Jesus del Hoyo;Pedro Moreno-Zárate;Gemán Escalante;Juan A. Vallés;Paloma Fernández;Javier Solís;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 2955 - 2959
Publisher: IEEE
 
» High-Gain Dual-Band Transmitarray
Abstract:
We propose a novel linearly polarized, dual-band, and high-gain transmitarray based on multilayer frequency-selective surface structures. This is the first time for actualizing a dual-band transmitarray with more than 50% aperture efficiency. The unit cell is composed of four metallic layers without dielectric substrates between every two layers, which results in good match, low insertion loss, and high radiation efficiency. We introduce two kinds of rectangular slots in the design to control the magnitude and phase range of transmission coefficients in the two designed frequency bands through changing the slot length. The isolation between two bands is excellent and the interference can be ignored. The induced electric fields of the cell are also investigated in order to elucidate the working principle intuitionally. The proposed dual-band transmitarray with a square aperture ( mm) is designed, fabricated, and measured. A linearly polarized corrugated horn antenna is adopted to improve the aperture efficiency and ensure the similarity of the radiation patterns on E-plane and H-plane. Full-wave simulation and experimental results have very good agreements. It is demonstrated that the dual-band transmitarray works in two frequency bands 11.8–12.2 and 17.5–18.1 GHz simultaneously, and the peak gains in the designed central frequencies 12 and 18 GHz are 27.8 and 31.4 dB, respectively, which correspond to the aperture efficiencies (global efficiencies) of 52% and 53%. The proposed design has advantages of simple structure, small weight, low cost, and high performance, making it possible for real applications.
Autors: Rui Yuan Wu;Yun Bo Li;Wei Wu;Chuan Bo Shi;Tie Jun Cui;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2017, volume: 65, issue:7, pages: 3481 - 3488
Publisher: IEEE
 
» High-Performance LED Drivers
Abstract:
The fourteen papers in this special section focus on high performance light emitting diode (LED) drivers. In recent years, as the fourth generation of light source, light-emitting diodes (LEDs) have been widely used in many applications such as street lighting, automotive, and residential lighting because of their long lifetime, low maintenance requirement, and environment friendliness. As the performance of LEDs will be influenced obviously by the drivers, researchers have shown a growing interest in optimizing the drivers. Although these problems such as current balancing, eliminating electrolytic capacitor, and improving the topologies are not new, the high-frequency high-efficiency trend of LED drivers has given rise to additional challenges. These papers provide an insight on some of the newly emerging challenges and potential solutions to overcome those issues.
Autors: Yijie Wang;J. Marcos Alonso;Xinbo Ruan;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5751 - 5753
Publisher: IEEE
 
» High-Performance Transmissive Meta-Surface for $C$ -/ $X$ -Band Lens Antenna Application
Abstract:
Conventional multiband transmissive devices suffer from strong interaction among different working frequencies, complex configurations, and low efficiencies. We propose a novel strategy to design high-performance dual-band transmissive meta-surfaces by using anisotropic ABBA systems (a four-layer system with identical structures in layers 1 and 4, and another group of identical structures in layers 2 and 3). The ABBA element provides a new freedom to enhance the transmission and suppress the fluctuations by tuning the coupling among cascaded layers. Dual-band operating property is performed by employing the polarization-related electromagnetic response. A well-designed transmissive meta-surface, operating at GHz and GHz, consists of ABBA elements with parabolic phase distributions. Good focusing effects with the same focal length and small reflection are observed at both frequencies under different polarizations. For practical applications, a dual-band lens antenna (LA) is implemented by launching the meta-lens with a self-made Vivaldi antenna. Numerical and experimental results coincide well, indicating that the proposed LA is better in many aspects such as high radiation gain, comparable aperture efficiencies to other designs in literature, and having a simple fabrication process. The finding opens up a new avenue to design high-performance meta-surfaces operating in multiband or achieving integrated functionalities.
Autors: Tong Cai;Guang-Ming Wang;Jian-Gang Liang;Ya-Qiang Zhuang;Tang-Jing Li;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2017, volume: 65, issue:7, pages: 3598 - 3606
Publisher: IEEE
 
» High-Power LED Photoelectrothermal Analysis Based on Backpropagation Artificial Neural Networks
Abstract:
As an electroluminescentdevice, the coupling relationship between light-emitting diode (LED) input currents, optical power, and LED junction temperature is a complicated multiphysics process. In this paper, a simplified LED photoelectron-thermal (PET) model by artificial neural network (ANN), which can translatemultiphysics field issue into a singlephysics field problem, ismentioned to study the coupling relationship. In the first, an LED lumens, optical power, and electric power at different temperatures are monitored in a temperature controlling integrating sphere. Then, a backpropagation (BP) ANN is trained by these data to construct an LED Photo-Electron-Thermal (PET) relationship. In addition, LED luminaire thermal analyzing is performed using a finite-element method on the outputs of the BP ANN. Finally, the advantage of this method in terms of saving computing resources and computing time is analyzed by comparing the degrees of freedom in different models. The result shows that at least 6.7 times computing resource are saved by this method, which will reduce the LED thermal management system analyzing time greatly. Finally, the application and extension of this model are discussed.
Autors: Hongwei Liu;Kai Guo;Zanyun Zhang;Dandan Yu;Jianxin Zhang;Pingfan Ning;Junchao Cheng;Xiaoyun Li;Pingjuan Niu;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2017, volume: 64, issue:7, pages: 2867 - 2873
Publisher: IEEE
 
» High-Power, Aperture Coupled Photonic Antenna
Abstract:
A high-power charge-compensated modified uni-travelling carrier photodetector is directly integrated into an aperture coupled patch antenna. The coupling technique offers not only good isolation between feed and radiating patch substrates but also wide operational bandwidth. The antenna is developed to operate at 22 GHz with 3-dB relative bandwidth of ~20%, over which the measured effective isotropic radiated power approaches 31 dBm. The photonic antenna is integrated with a lightweight, low form factor fiber-optic feed that demonstrates potential for future wireless communications applications. The antenna’s electrical and radiation characteristics are observed to be in good agreement with simulations.
Autors: Matthew R. Konkol;Dylan D. Ross;Kevin P. Shreve;Charles E. Harrity;Shouyuan Shi;Christopher A. Schuetz;Dennis W. Prather;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jul 2017, volume: 29, issue:14, pages: 1207 - 1210
Publisher: IEEE
 
» High-Speed Tracking of a Nanopositioning Stage Using Modified Repetitive Control
Abstract:
In this paper, a modified repetitive control (MRC) based approach is developed for high-speed tracking of nanopositioning stages. First, the hysteresis nonlinearity is decomposed as a periodic disturbance over a linear system. Then, the MRC technique is utilized to account for the periodic disturbances/errors caused by the hysteresis and dynamics behaviors. The developed approach provides a simple and effective hysteresis compensation strategy, avoiding the constructions of hysteresis model and its inversion. Besides, with improved loop-shaping properties, the MRC can alleviate the nonperiodic disturbance amplification problem of the conventional repetitive control. Finally, the effectiveness and performance of the developed MRC-based approach are verified by the experimental results on a custom-built piezo-actuated stage in terms of hysteresis compensation, disturbance rejection and tracking accuracy.
Autors: Chun-Xia Li;Guo-Ying Gu;Mei-Ju Yang;Li-Min Zhu;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jul 2017, volume: 14, issue:3, pages: 1467 - 1477
Publisher: IEEE
 
» High-Thermal Performance 3D Hybrid Silicon Lasers
Abstract:
A 3D integrated hybrid silicon laser was realized for high-thermal performance by integrating silicon photonic (SiPh) chips and indium phosphide (InP) chips. The optical gain is provided by the InP chip with a total internal reflection mirror for surface emission. The surface grating couplers on the SiPh chip couples light into a silicon waveguide. The InP chips were flip-chip bonded P-side down to metal pads on the silicon chips. Two lasers are reported. For laser A, the InP chip was bonded on the top cladding oxide of the silicon waveguide. For laser B, the InP chip was bonded to the silicon substrate in an etched recess. Both lasers demonstrate milliwatt-level light coupled into the silicon waveguide. Laser B demonstrated three times better thermal performance with a measured thermal impedance of 6.2 °C/W.
Autors: Bowen Song;Ludovico Megalini;Sarvagya Dwivedi;Sasa Ristic;Jonathan Klamkin;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jul 2017, volume: 29, issue:14, pages: 1143 - 1146
Publisher: IEEE
 
» High-Throughput Network Coding Aware Routing in Time-Varying Multihop Networks
Abstract:
Network coding aware routing (NCAR) has been emerging as an effective approach to create coding opportunities actively in multihop networks. To the best of our knowledge, most of the existing methods focus on a “static” design that considers coding opportunities based on fixed routes and invariable packet flows. This “static” way results in the optimality of routes suffering from a high sensitive behavior on both network topology and flow dynamic and, hence, reduces the throughput of routes in time-varying networks. To solve this problem, we propose a high-throughput NCAR scheme that supports dynamic multihop network connectivity and achieves throughput optimization, even with multiple variable flows. In the proposed scheme, a back-pressure-based NCAR algorithm is designed to push the flows dynamically into the nodes that have better network coding opportunities with no knowledge of network topology and flow dynamic. As a byproduct, the proposed method also exhibits a significantly improved delay performance relative to the traditional back-pressure algorithm. Simulation results reveal that the proposed scheme improves network capacity and alleviates end-to-end delay in heavy load networks.
Autors: Long Hai;Jie Wang;Ping Wang;Hongyu Wang;Tingting Yang;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 6299 - 6309
Publisher: IEEE
 
» High-Throughput Non-Binary LDPC Decoder Based on Aggressive Overlap Scheduling
Abstract:
Non-binary LDPC (NB-LDPC) codes offer better error correcting performance than their binary counterparts. However, to achieve excellent performance, decoding complexity and large memory are required, which makes it difficult to implement the high-throughput decoder. This paper presents a fully overlapped NB-LDPC decoder using three proposed techniques to improve throughput performance. First, an early bubble check is presented to reduce the initialization latency of the check node processing (CNP). Second, the CNP and variable node processing (VNP) are overlapped with the proposed backward memory scan method to hide the CNP latency within the VNP. Finally, we propose a redundant memory reuse technique to further decrease the latency of a single decoding iteration. We implemented the high-throughput decoder for (160, 80) regular (2, 4) NB-LDPC code over GF (64). The iteration latency was decreased by up to 57.5% with our three proposed methods. The proposed decoder achieved a throughput of 2.22 Gb/s at a 625-MHz frequency with 2.96-M gates in a 65-nm CMOS process. The proposed decoder showed outstanding area efficiency compared with the state-of-the-art decoders.
Autors: Injun Choi;Ji-Hoon Kim;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jul 2017, volume: 64, issue:7, pages: 1937 - 1948
Publisher: IEEE
 
» Higher Order Super-Twisting for Perturbed Chains of Integrators
Abstract:
In this paper, we present a generalization of the super-twisting algorithm for perturbed chains of integrators of arbitrary order. This higher order super-twisting (HOST) controller is homogeneous with respect to a family of dilations and is continuous. It is built as a dynamic controller (with respect to the state variable of the chain of integrators) and the convergence analysis is performed by the use of a homogeneous strict Lyapunov function which is explicitly constructed. The effectiveness of the controller is finally illustrated with simulations for a chain of integrators of order four, first pure then perturbed, where we compare the performances of two HOST controllers.
Autors: Salah Laghrouche;Mohamed Harmouche;Yacine Chitour;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3588 - 3593
Publisher: IEEE
 
» Highly Integrated 3 V Supply Electronics for Electromagnetic Energy Harvesters With Minimum 0.4 V $_{\mathbf{peak}}$ Input
Abstract:
This paper presents a self-powered interface enabling battery-like operation with a regulated 3 V output from ac signals as low as 0.4 Vpeak, generated by electromagnetic energy harvesters under low frequency vibrations. As the first stage of the 180 nm standard CMOS circuit, harvested signal is rectified through an ac/dc doubler with active diodes powered internally by a passive ac/dc quadrupler. The voltage is boosted in the second stage through a low voltage charge pump stimulated by an on-chip ring oscillator. The output is finally regulated to 3 V at the last stage. The voltage doubling rectification stage deviates by less than 40 mV from ideal expectation for the validated 0.15–1 V input voltage range. The full system delivers 3 V output to 4.4 MΩ load for input voltage of 0.4 V peak, which is the lowest operable input voltage in the literature. The demonstrated system generates 9 μW of dc power with 3 V stable output for 32 μW input, whereas the circuit is able to supply even more output power for higher input power levels. The maximum efficiency of the rectification stage is 86%, while the full system efficiency is 37% and 28% for unregulated and regulated operation, respectively, when interfaced to an in-house electromagnetic energy harvester under 8 Hz 0.1 g vibration.
Autors: Hasan Uluşan;Özge Zorlu;Ali Muhtaroğlu;Haluk Külah;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5460 - 5467
Publisher: IEEE
 
» Highly Scaled Ruthenium Interconnects
Abstract:
Ruthenium has emerged as a promising candidate to substitute Cu as the interconnect metallization in future technology nodes. Here, we demonstrate area scaling of Ru wires down to cross-sectional areas of 33 nm2 through subtractive patterning by using a metal-spacer patterning technique. The wires were characterized by physical as well as electrical measurements and demonstrate low resistivity, between 20 and cm for cross-sectional areas between 175 and 33 nm2.
Autors: Shibesh Dutta;Shreya Kundu;Anshul Gupta;Geraldine Jamieson;Juan Fernando Gomez Granados;Jürgen Bömmels;Christopher J. Wilson;Zsolt Tőkei;Christoph Adelmann;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2017, volume: 38, issue:7, pages: 949 - 951
Publisher: IEEE
 
» Hollow-Core Fiber-Based High Finesse Resonating Cavity for High Sensitivity Gas Detection
Abstract:
High finesse hollow-core photonic bandgap fiber (HC-PBF) resonating Fabry-Perot gas cells are presented. These gas cells are made with a piece of HC-PBF sandwiched by two single mode fibers with mirrored ends. A HC-PBF cavity made with 6.75-cm-long HC-1550-06 fiber achieved a cavity finesse of 128, corresponding to an effective optical path length of ~5.5 m. Experiment with a 9.4-cm-long Fabry-Perot gas cell with a finesse of 68 demonstrated a detection limit of 7 ppm acetylene. Compared with a single-path nonresonating HC-PBF, the use of a high finesse resonating HC-PBF cavity can reduce significantly the effect of modal interference on gas detection and improve the detection sensitivity. The cavity-enhanced HC-PBF gas cells enable stronger light-gas interaction and can be used to develop all-fiber gas sensors with high sensitivity and fast response.
Autors: Yanzhen Tan;Wei Jin;Fan Yang;Yun Qi;Congzhe Zhang;Yuechuan Lin;Hoi Lut Ho;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 2887 - 2893
Publisher: IEEE
 
» Homology Parameters for Large Axisymmetric Shaped Dual-Reflector Antennas
Abstract:
We extend the concept of best-fitting paraboloids for large single and dual reflectors with conic-section surfaces to best-fit shaped surface for large dual reflectors shaped for uniform amplitude distribution. The point focus of the paraboloidal main reflector is replaced by focal lines for the main reflector and the primary subreflector focus, whereas the secondary subreflector point focus at the feed is kept. The reflector surfaces are shaped, and all rays from the main-reflector aperture to the feed meet an equal-path-length condition. This condition may be represented by a set of “homology parameters” determined by a least-squares method. Finally, we calculate the homology parameters and the root mean square of surface errors for an 8-m dual-reflector system including gravity effects for the antenna pointed toward zenith and the horizon.
Autors: You Ban;Baoyan Duan;Congsi Wang;Wei Wang;Shufei Feng;Binbin Xiang;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2017, volume: 65, issue:7, pages: 3392 - 3398
Publisher: IEEE
 
» Hopf Bifurcation Control of Power System Nonlinear Dynamics via a Dynamic State Feedback Controller–Part I: Theory and Modeling
Abstract:
This two-part paper introduces a dynamic state feedback control law that guarantees the elimination of Hopf bifurcations (HB) before reaching the saddle-node bifurcations (SNB). Part I is devoted to the mathematical representation of the detailed system dynamics, investigation of HB and SNB theorems, and state feedback controller design. For purposes of dynamical analysis, the stable equilibria of the system is obtained. Then the control system is designed with the objective of preventing the voltage collapse before the SNB, such that the structural stability of the system is preserved in the stationary branch of the solutions. The controller aims to relocate Hopf bifurcations to the stationary branch of solutions located after SNB, eliminating the HB from normal operating region of the system. In order to evaluate the performance of the proposed controller, bifurcation analysis has been performed in Part II using single-machine and multi-machine test systems.
Autors: Pouya Mahdavipour Vahdati;Ahad Kazemi;M. Hadi Amini;Luigi Vanfretti;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 3217 - 3228
Publisher: IEEE
 
» Hopf Bifurcation Control of Power Systems Nonlinear Dynamics Via a Dynamic State Feedback Controller—Part II: Performance Evaluation
Abstract:
This is the second part of a two-part paper presenting a dynamic state feedback control law that guarantees the elimination of Hopf bifurcations before the occurrence of a saddle-node bifurcation. In Part I, the mathematical representation of the system's dynamics, Hopf, and Saddle-Node bifurcation theorems, and the state feedback controller design were presented. In this part, to illustrate the system analysis methodology, control design, and to carry out performance evaluation of the controller, both single-machine and multimachine power systems are analyzed. To highlight the effect of saturation phenomena, bifurcation analyses are performed before and after detailed modeling of synchronous generator saturation, for the single-machine power system case. The multimachine case is used to illustrate the scalability and applicability of the method to generic power networks.
Autors: Pouya Mahdavipour Vahdati;Luigi Vanfretti;M. Hadi Amini;Ahad Kazemi;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 3229 - 3236
Publisher: IEEE
 
» HOTS: A Hierarchy of Event-Based Time-Surfaces for Pattern Recognition
Abstract:
This paper describes novel event-based spatio-temporal features called time-surfaces and how they can be used to create a hierarchical event-based pattern recognition architecture. Unlike existing hierarchical architectures for pattern recognition, the presented model relies on a time oriented approach to extract spatio-temporal features from the asynchronously acquired dynamics of a visual scene. These dynamics are acquired using biologically inspired frameless asynchronous event-driven vision sensors. Similarly to cortical structures, subsequent layers in our hierarchy extract increasingly abstract features using increasingly large spatio-temporal windows. The central concept is to use the rich temporal information provided by events to create contexts in the form of time-surfaces which represent the recent temporal activity within a local spatial neighborhood. We demonstrate that this concept can robustly be used at all stages of an event-based hierarchical model. First layer feature units operate on groups of pixels, while subsequent layer feature units operate on the output of lower level feature units. We report results on a previously published 36 class character recognition task and a four class canonical dynamic card pip task, achieving near 100 percent accuracy on each. We introduce a new seven class moving face recognition task, achieving 79 percent accuracy.
Autors: Xavier Lagorce;Garrick Orchard;Francesco Galluppi;Bertram E. Shi;Ryad B. Benosman;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jul 2017, volume: 39, issue:7, pages: 1346 - 1359
Publisher: IEEE
 
» How Biometric Authentication Poses New Challenges to Our Security and Privacy [In the Spotlight]
Abstract:
Discusses the challenges that face biometric authentication in the areas of privacy and network security. The use of biometric data — an individual’s measurable physical and behavioral characteristics — isn’t new. Government and law enforcement agencies have long used it. The Federal Bureau of Investigation (FBI) has been building a biometric recognition database; the U.S. Department of Homeland Security is sharing its iris and facial recognition of foreigners with the FBI. But the use of biometric data by consumer goods manufacturers for authentication purposes has skyrocketed in recent years. For example, Apple’s iPhone allows users to scan their fingerprints to unlock the device, secure mobile bill records, and authenticate payments. Lenovo and Dell are companies that leverage fingerprints to enable users to sign onto their computers with just a swipe. Using biometric data to access our personal devices is increasing as a way to get around the limitations of the commonly used password-based mechanism: it’s easier, more convenient, and (theoretically) more secure. But biometric data can also be stolen and used in malicious ways. Capturing fingerprints at scale isn’t as easy as lifting a credit card or Social Security number, but experience and history tells us that once something is used extensively, criminals will figure out how to misuse and monetize it.
Autors: Nasir Memon;
Appeared in: IEEE Signal Processing Magazine
Publication date: Jul 2017, volume: 34, issue:4, pages: 196 - 194
Publisher: IEEE
 
» How Much Spectrum is too Much in Millimeter Wave Wireless Access
Abstract:
Great increase in wireless access rates might be attainable using the large amount of spectrum available in the millimeter wave (mmWave) band. However, higher propagation losses inherent in these frequencies must be addressed, especially at ranges beyond 100 m and in non-line-of-sight (NLOS) settings. In contrast to the interference limited legacy cellular systems, where using more bandwidth is favorable, to use wider bandwidth for mmWave channels in noise limited settings may be ineffective or even counterproductive when accounting for channel estimation penalty. In this paper, we quantify the maximum beneficial bandwidth for mmWave transmission in some typical deployment scenarios where pilot-based channel estimation penalty is considered assuming a minimum mean square error channel estimator at the receiver. We find that, under I.I.D. block fading model with coherence time and coherence bandwidth , for transmitters and receivers equipped with a single antenna, the optimal (rate maximizing) signal-to-noise-ratio is a constant that only depends on the product , which measures the channel coherence and equals the average number of orthogonal symbols per each independent channel coefficient. That is, for fixed channel coherence , the optimal bandwidth scales linearly with the received signal power. Under 3GPP urban micro NLOS path loss model with coherence time ms and coherence bandwidth MHz, using 52-dBm equivalent isotropic radiated power (EIRP) at the transmitter and 11-dBi - ntenna gain at the receiver, the maximum beneficial bandwidth at 28 (resp. 39) GHz is less than 1 GHz at a distance beyond 210 (resp. 170) m with maximum throughput about 200 Mbps, and less than 100 MHz beyond 400 (resp. 310) m with maximum throughput about 20 Mbps. At EIRP of 85 dBm, corresponding to the FCC limit of 75 dBm per 100 MHz, 1 Gbps rate can be delivered using 1-GHz bandwidth up to 860 (resp. 680) m.
Autors: Jinfeng Du;Reinaldo A. Valenzuela;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jul 2017, volume: 35, issue:7, pages: 1444 - 1458
Publisher: IEEE
 
» Human-Powered Data Cleaning for Probabilistic Reachability Queries on Uncertain Graphs
Abstract:
Uncertain graph models are widely used in real-world applications such as knowledge graphs and social networks. To capture the uncertainty, each edge in an uncertain graph is associated with an existential probability that signifies the likelihood of the existence of the edge. One notable issue of querying uncertain graphs is that the results are sometimes uninformative because of the edge uncertainty. In this paper, we consider probabilistic reachability queries, which are one of the fundamental classes of graph queries. To make the results more informative, we adopt a crowdsourcing-based approach to clean the uncertain edges. However, considering the time and monetary cost of crowdsourcing, it is a problem to efficiently select a limited set of edges for cleaning that maximizes the quality improvement. We prove that the edge selection problem is #P-hard. In light of the hardness of the problem, we propose a series of edge selection algorithms, followed by a number of optimization techniques and pruning heuristics for reducing the computation time. Our experimental results demonstrate that our proposed techniques outperform a random selection by up to 27 times in terms of the result quality improvement and the brute-force solution by up to 60 times in terms of the elapsed time.
Autors: Xin Lin;Yun Peng;Byron Choi;Jianliang Xu;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Jul 2017, volume: 29, issue:7, pages: 1452 - 1465
Publisher: IEEE
 
» Hurricanes and Power System Reliability-The Effects of Individual Decisions and System-Level Hardening
Abstract:
Hurricanes produce significant, widespread, and often prolonged electrical-power outages. For example, Hurricane Irene caused more than 500 000 Long Island Power Authority customers to lose power and it took eight days to achieve 99% customer restoration. Individuals and businesses are heavily dependent on a continuous supply of electricity. Given this strong dependence on reliable electricity, individuals and private industries are increasingly putting collective pressure on regulators to require system hardening by utilities. In some cases, this has led to utility action. Conversely, many customers install a backup generator to guarantee electricity supply during disruptive events. These actions taken by individual customers affect their experiences in future storms, and are generally influenced by individuals’ strength of preference for reliable power, their beliefs about the likelihood of losing power in the future, and the outcomes of their most recent experiences. However, individual action may come at the expense of collective action, whereby those who buy generators, often those with more resources available to purchase the generator, do not participate in the collective grievance, reducing the demand for overall system hardening. By using a validated power-outage forecasting model in conjunction with an agent-based model, we characterize how a community’s likelihood of losing power in repeated hurricanes is affected by the complex interactions among individuals’ behavioral responses in whether to engage in personal or collective action.
Autors: Allison C. Reilly;Gina L. Tonn;Chengwei Zhai;Seth D. Guikema;
Appeared in: Proceedings of the IEEE
Publication date: Jul 2017, volume: 105, issue:7, pages: 1429 - 1442
Publisher: IEEE
 
» Hybrid Analog and Digital Beamforming for mmWave OFDM Large-Scale Antenna Arrays
Abstract:
Hybrid analog and digital beamforming is a promising candidate for large-scale millimeter wave (mmWave) multiple-input multiple-output (MIMO) systems because of its ability to significantly reduce the hardware complexity of the conventional fully digital beamforming schemes while being capable of approaching the performance of fully digital schemes. Most of the prior work on hybrid beamforming considers frequency-flat channels. However, broadband mmWave systems are frequency-selective. In broadband systems, it is desirable to design common analog beamformer for the entire band while employing different digital (baseband) beamformers in different frequency sub-bands. This paper considers the hybrid beamforming design for systems with orthogonal frequency division multiplexing modulation. First, for a single-user MIMO (SU-MIMO) system where the hybrid beamforming architecture is employed at both transmitter and receiver, we show that hybrid beamforming with a small number of radio frequency (RF) chains can asymptotically approach the performance of fully digital beamforming for a sufficiently large number of transceiver antennas due to the sparse nature of the mmWave channels. For systems with a practical number of antennas, we then propose a unified heuristic design for two different hybrid beamforming structures, the fully connected and the partially connected structures, to maximize the overall spectral efficiency of an mmWave MIMO system. Numerical results are provided to show that the proposed algorithm outperforms the existing hybrid beamforming methods, and for the fully connected architecture, the proposed algorithm can achieve spectral efficiency very close to that of the optimal fully digital beamforming but with much fewer RF chains. Second, for the multiuser multiple-input single-output case, we propose a heuristic hybrid percoding design to maximize the weighted sum rate in the downlink and show numerically that the proposed algorithm with practical numb- r of RF chains can already approach the performance of fully digital beamforming.
Autors: Foad Sohrabi;Wei Yu;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jul 2017, volume: 35, issue:7, pages: 1432 - 1443
Publisher: IEEE
 
» Hybrid Islanding Detection in Microgrid With Multiple Connection Points to Smart Grids Using Fuzzy-Neural Network
Abstract:
This paper presents a new hybrid islanding detection approach for microgrids (MGs) with multiple connection points to smart grids (SGs) which is based on the probability of islanding (PoI) calculated at the SG side and sent to the central control for microgrid (CCMG). The PoI values are determined using a combination of passive, active, and communication islanding detection approaches based on the utility signals measured at the SGs sides which are processed by discrete wavelet transform using an artificial neural network (ANN). If is larger than the threshold value (indicating high possibility of islanding) then a more accurate approach based on fuzzy network is used to recompute it () where the fuzzy parameters are determined by an adaptive neuro-fuzzy inference system. In the proposed technique, an active islanding is only performed when PoI is high and the amplitudes of the disturb signals are proportional to . Furthermore, if the PoI is not correctly received by CCMG, two auxiliary tests will be performed in the MG side to detect islanding. These tests include an intentional passive islanding detection in a short preset time and an active islanding detection with disturb signals proportional to the calculated PoI. Detailed simulations are performed and analyzed to evaluate the performance of the proposed method.
Autors: Saman Darvish Kermany;Mahmood Joorabian;Sara Deilami;Mohammad A. S. Masoum;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 2640 - 2651
Publisher: IEEE
 
» Hybrid-Tamm-Plasmon-Polariton Based Self-Reference Temperature Sensor
Abstract:
We propose a hybrid Tamm-plasmon-polariton (TPP) mode based sensing scheme for accurate determination of temperature. The sensing architecture is comprised of dual “metal-distributed-Bragg-reflector (DBR)” based structure, which sandwiches a common layer acting as a temperature sensing medium. Hybrid-TPP modes formed as a consequence of individual TPP mode-coupling is characterized by two distinct sharp reflectivity minima within the photonic bandgap of DBR for normal incidence of broadband source. The symmetric hybrid mode exhibits discernible variation in terms of change in reflectivity and resonance wavelength as the temperature of the sensing layer alters. On the other hand, the antisymmetric mode remains unchanged that gives rise to self-referenced temperature sensing scheme. We obtained a spectral sensitivity of 50 pm/°C by optimally choosing the thickness of sensing layer. In addition, the sharp TPP resonances gives rise to improved detection accuracy of such a sensing configuration as compared to competing optical sensing technologies.
Autors: Partha Sona Maji;Ritwick Das;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 2833 - 2839
Publisher: IEEE
 
» Hybrid-Type Temperature Sensor Using Poly-Si Thin-Film Transistors Outputting Rectangle Waveforms
Abstract:
We have succeeded in developing a hybrid-type temperature sensor using poly-Si thin-film transistors (TFTs) that outputs rectangle waveforms. An advantage of the conventional hybrid-type sensor is that large temperature dependences of off-leakage currents can be utilized, and it simultaneously works in a digital operation tolerant of noises. Additionally, in this paper, by connecting two conventional ones, the sensor becomes able to output rectangle waveforms, which can be easily counted. We confirm the waveform and that the sensor can detect the correct temperature. We think that it is promising to integrate this temperature sensor in some applications using TFTs.
Autors: Hisashi Hayashi;Tokiyoshi Matsuda;Mutsumi Kimura;
Appeared in: IEEE Sensors Journal
Publication date: Jul 2017, volume: 17, issue:14, pages: 4365 - 4368
Publisher: IEEE
 
» Hypersensitive and Tunable Terahertz Wave Switch Based on Non-Bragg Structures Filled with Liquid Crystals
Abstract:
We investigated a hypersensitive and tunable terahertz (THz) wave switch based on liquid-crystal-filled non-Bragg structures. Non-Bragg structures, which consist of periodically corrugated metallic tube walls, provide spectra with very sharp rising edges, making them usable for sensitive switching. Tunability can be achieved by dynamically shifting the rising edge of a THz spectrum by using an externally applied magnetic field to change the orientations of the nematic liquid crystal (E7) molecules. The simulated results revealed that the switch effects are hypersensitive and tunable in the THz frequency range and that such switches could be applicable in future THz systems.
Autors: Lu Zhang;Ya-Xian Fan;Huan Liu;Lan-Lan Xu;Jiu-Ling Xue;Zhi-Yong Tao;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 3092 - 3098
Publisher: IEEE
 
» Hyperspectral and LiDAR Fusion Using Extinction Profiles and Total Variation Component Analysis
Abstract:
The classification accuracy of remote sensing data can be increased by integrating ancillary data provided by multisource acquisition of the same scene. We propose to merge the spectral and spatial content of hyperspectral images (HSIs) with elevation information from light detection and ranging (LiDAR) measurements. In this paper, we propose to fuse the data sets using orthogonal total variation component analysis (OTVCA). Extinction profiles are used to automatically extract spatial and elevation information from HSI and rasterized LiDAR features. The extracted spatial and elevation information is then fused with spectral information using the OTVCA-based feature fusion method to produce the final classification map. The extracted features have high dimension, and therefore OTVCA estimates the fused features in a lower dimensional space. OTVCA also promotes piece-wise smoothness while maintaining the spatial structures. Both attributes are important to provide homogeneous regions in the final classification maps. We benchmark the proposed approach (OTVCA-fusion) with an urban data set captured over an urban area in Houston/USA and a rural region acquired in Trento/Italy. In the experiments, OTVCA-fusion is evaluated using random forest and support vector machine classifiers. Our experiments demonstrate the ability of OTVCA-fusion to produce accurate classification maps while using fewer features compared with other approaches investigated in this paper.
Autors: Behnood Rasti;Pedram Ghamisi;Richard Gloaguen;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jul 2017, volume: 55, issue:7, pages: 3997 - 4007
Publisher: IEEE
 
» Hyperspectral Anomaly Detection Using Attribute Profiles
Abstract:
Over the past decade, anomaly detection has been an alluring topic in hyperspectral imagery. Despite most anomaly detection methods that focus on spectral information for detecting targets, this letter proposes a method in which both spectral and spatial information about the hyperspectral image (HSI) has been utilized for detecting anomalies. The differential attribute profile anomaly detection (DAPAD) method utilizes principal component analysis and DAP to extract spectral and spatial information from HSI, respectively. DAPs can model different kinds of structural information in a scene, which makes better extraction of spatial information. The proposed method is applied in experiments on Hyperspectral Digital Imagery Collection Experiment remote sensing data and the experimental results confirm the DAPAD method’s superiority over five commonly used state-of-the-art anomaly detection methods.
Autors: Ashkan Taghipour;Hassan Ghassemian;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jul 2017, volume: 14, issue:7, pages: 1136 - 1140
Publisher: IEEE
 
» Hyperspectral Image Classification via Multiple-Feature-Based Adaptive Sparse Representation
Abstract:
A multiple-feature-based adaptive sparse representation (MFASR) method is proposed for the classification of hyperspectral images (HSIs). The proposed method mainly includes the following steps. First, four different features are separately extracted from the original HSI and they reflect different kinds of spectral and spatial information. Second, for each pixel, a shape adaptive (SA) spatial region is extracted. Third, an adaptive sparse representation algorithm is introduced to obtain the sparse coefficients for the multiple-feature matrix set of pixels in each SA region. Finally, these obtained coefficients are jointly used to determine the class label of each test pixel. Experimental results demonstrated that the proposed MFASR method can outperform several well-known classifiers in terms of both qualitative and quantitative results.
Autors: Leyuan Fang;Cheng Wang;Shutao Li;Jón Atli Benediktsson;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1646 - 1657
Publisher: IEEE
 
» Hyperspectral Image Restoration Using Low-Rank Representation on Spectral Difference Image
Abstract:
This letter presents a novel mixed noise (i.e., Gaussian, impulse, stripe noises, or dead lines) reduction method for hyperspectral image (HSI) by utilizing low-rank representation (LRR) on spectral difference image. The proposed method is based on the assumption that all spectra in the spectral difference space of HSI lie in the same low-rank subspace. The LRR on the spectral difference space was exploited by nuclear norm of difference image along the spectral dimension. It showed great potential in removing structured sparse noise (e.g., stripes or dead lines located at the same place of each band) and heavy Gaussian noise. To simultaneously solve the proposed model and reduce computational load, alternating direction method of multipliers was utilized to achieve robust reconstruction. The experimental results on both simulated and real HSI data sets validated that the proposed method outperformed many state-of-the-art methods in terms of quantitative assessment and visual quality.
Autors: Le Sun;Byeungwoo Jeon;Yuhui Zheng;Zebin Wu;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jul 2017, volume: 14, issue:7, pages: 1151 - 1155
Publisher: IEEE
 
» Hyperspectral Image Superresolution Based on Double Regularization Unmixing
Abstract:
This letter proposes a novel double regularization unmixing-based method for hyperspectral image (HSI) superresolution. The proposed cost function contains two data-fidelity terms, the endmember regularization term and the abundance regularization term. Since the double regularization unmixing terms are able to exploit the spatial structure information of endmember and abundance, respectively, the nonnegative factorization (spectral unmixing) error is minimized. As a result, the performance of the proposed HSI superresolution method can be enhanced in terms of noise suppression and the special structure information preservation of reconstruction images. Finally, the associated optimization problem is effectively solved by an alternating direction optimization algorithm. Simulation results illustrate that the proposed method has a better performance than the state-of-the-art methods in terms of both visual effectiveness and quality indices.
Autors: Changzhong Zou;Youshen Xia;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jul 2017, volume: 14, issue:7, pages: 1022 - 1026
Publisher: IEEE
 
» Hyperspectral Imagery Classification With Multiple Regularized Collaborative Representations
Abstract:
Recent advances have shown a great potential to explore collaborative representations in hyperspectral imagery (HSI) classification, including sparse representations and joint collaborative representations. In this letter, we propose a weighted regularized collaborative representation optimized classifier (WRCROC) that makes use of multiple collaborative representations. It strikes a balance between an optimized weighted joint collaborative representation classifier, which essentially classifies a test sample to the class that minimizes the distance between the sample and its representation in the selected class, and a weighted regularized collaborative representation classifier, which actually assigns a test sample to the class that minimizes the distance between the sample and its collaborative components. The proposed WRCROC algorithm is tested on two benchmark HSI data sets. Experimental results demonstrate that the proposed algorithm performs better than existing representation-based classifiers.
Autors: Xiang Chen;Shuying Li;Jiangtao Peng;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jul 2017, volume: 14, issue:7, pages: 1121 - 1125
Publisher: IEEE
 
» Hyperspectral Unmixing Using Double Reweighted Sparse Regression and Total Variation
Abstract:
Spectral unmixing is an important technique in hyperspectral image applications. Recently, sparse regression has been widely used in hyperspectral unmixing, but its performance is limited by the high mutual coherence of spectral libraries. To address this issue, a new sparse unmixing algorithm, called double reweighted sparse unmixing and total variation (TV), is proposed in this letter. Specifically, the proposed algorithm enhances the sparsity of fractional abundances in both spectral and spatial domains through the use of double weights, where one is used to enhance the sparsity of endmembers in spectral library, and the other is introduced to improve the sparsity of fractional abundances. Moreover, a TV-based regularization is further adopted to explore the spatial–contextual information. As such, the simultaneous utilization of both double reweighted minimization and TV regularizer can significantly improve the sparse unmixing performance. Experimental results on both synthetic and real hyperspectral data sets demonstrate the effectiveness of the proposed algorithm both visually and quantitatively.
Autors: Rui Wang;Heng-Chao Li;Aleksandra Pizurica;Jun Li;Antonio Plaza;William J. Emery;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jul 2017, volume: 14, issue:7, pages: 1146 - 1150
Publisher: IEEE
 
» IcoNoClast: Tackling Voltage Noise in the NoC Power Supply Through Flow-Control and Routing Algorithms
Abstract:
Power supply noise (PSN) is a growing concern in modern multiprocessor system-on-chips (MPSoCs). The advent of new architectures, such as the network-on-chip (NoC), the standard for on-chip communication in MPSoCs, has given rise to new challenges in maintaining reliable and energy-efficient operation. The growing NoC power footprint, increase in the transistor current, and high switching speed of the logic devices exacerbate the peak PSN in the NoC power delivery network (PDN). Hence, preserving power supply integrity in the NoC PDN is critical. In this paper, we propose IcoNoClast, a collection of a novel flow-control protocol (PAF) and an adaptive routing algorithm (PSN-aware routing), to mitigate the PSN in NoCs. Our best scheme achieves ~15% and ~12% improvements in the regional peak PSN and energy efficiency across a range of PARSEC benchmarks, with a 4.1% performance overhead and marginal area and power footprints.
Autors: Prabal Basu;Rajesh Jayashankara Shridevi;Koushik Chakraborty;Sanghamitra Roy;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jul 2017, volume: 25, issue:7, pages: 2035 - 2044
Publisher: IEEE
 
» Ideal Kernel-Based Multiple Kernel Learning for Spectral-Spatial Classification of Hyperspectral Image
Abstract:
Using multiple types of features can effectively improve the classification accuracy of hyperspectral image (HSI). Multiple kernel learning (MKL) provides a flexible framework to fuse different features in a very natural way. In this letter, a novel MKL algorithm is proposed to integrate multiple types of features [i.e., principal components of original spectrum, multistructure morphological profiles (MPs), and multiattribute MPs] for HSI classification. The basic kernels are constructed with each feature subset separately, and the weights of basic kernels are determined by solving an optimization problem with the objective of the ideal kernel. Then, linear programming (LP) and signal sparse representation are adopted to solve the optimization problem, thus leading to two variants of the proposed algorithm, ideal kernel MKL (IKMKL)-LP and IKMKL-sparse, respectively. Experiments carried out on real hyperspectral data show that the proposed algorithms outperform several state-of-the-art MKL algorithms and reveal the capability of ranking the relevant features.
Autors: Wei Gao;Yu Peng;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jul 2017, volume: 14, issue:7, pages: 1051 - 1055
Publisher: IEEE
 
» Identifiability and Stability in Blind Deconvolution Under Minimal Assumptions
Abstract:
Blind deconvolution (BD) arises in many applications. Without assumptions on the signal and the filter, BD does not admit a unique solution. In practice, subspace or sparsity assumptions have shown the ability to reduce the search space and yield the unique solution. However, existing theoretical analysis on uniqueness in BD is rather limited. In an earlier paper, we provided the first algebraic sample complexities for BD that hold for Lebesgue almost all bases or frames. We showed that for BD of a pair of vectors in , with subspace constraints of dimensions and , respectively, a sample complexity of is sufficient. This result is suboptimal, since the number of degrees of freedom is merely . We provided analogous results, with similar suboptimality, for BD with sparsity or mixed subspace and sparsity constraints. In this paper, taking advantage of the recent progress on the information-theoretic limits of unique low-rank matrix recovery, we finally bridge this gap, and derive an optimal sample complexity result for BD with generic bases or frames. We show that for BD of an arbitrary pair (respectively, all pairs) of vectors in , with sparsity constraints of sparsity levels and , a sample complexity of [respectively, ] is sufficient. We also present analogous results for BD with subspace constraints or mixed constraints, with the subspace dimension replacing the sparsity level. Last but not least, in all the above scenarios, if the bases or frames follow a probabilistic distribution specified in this paper, the recovery is not only unique, but also stable against small perturbations in the measurements, under the same sample complexities.
Autors: Yanjun Li;Kiryung Lee;Yoram Bresler;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jul 2017, volume: 63, issue:7, pages: 4619 - 4633
Publisher: IEEE
 
» Identifying Biases of a Defect Diagnosis Procedure
Abstract:
A defect diagnosis procedure is an important part of the yield improvement process. As defects become more complex, the output responses they produce differ to larger extents from the output responses of modeled faults, and they become more difficult to diagnose. Biases in the defect diagnosis procedure can also cause defects to be more difficult to diagnose. It is important to study and remove such biases in order to ensure that they do not affect the accuracy of the procedure. This paper undertakes a study of the biases of a defect diagnosis procedure and suggests a way to improve it. The study illustrates an approach by which biases in defect diagnosis procedures can be analyzed in general.
Autors: Irith Pomeranz;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jul 2017, volume: 36, issue:7, pages: 1215 - 1225
Publisher: IEEE
 
» IEEE Young Professionals ... Who Are They? [The Way Ahead]
Abstract:
Autors: J. Patrick Donohoe;
Appeared in: IEEE Potentials
Publication date: Jul 2017, volume: 36, issue:4, pages: 5 - 5
Publisher: IEEE
 
» Image Aesthetic Assessment: An experimental survey
Abstract:
This article reviews recent computer vision techniques used in the assessment of image aesthetic quality. Image aesthetic assessment aims at computationally distinguishing high-quality from low-quality photos based on photographic rules, typically in the form of binary classification or quality scoring. A variety of approaches has been proposed in the literature to try to solve this challenging problem. In this article, we summarize these approaches based on visual feature types (hand-crafted features and deep features) and evaluation criteria (data set characteristics and evaluation metrics). The main contributions and novelties of the reviewed approaches are highlighted and discussed. In addition, following the emergence of deep-learning techniques, we systematically evaluate recent deep-learning settings that are useful for developing a robust deep model for aesthetic scoring.
Autors: Yubin Deng;Chen Change Loy;Xiaoou Tang;
Appeared in: IEEE Signal Processing Magazine
Publication date: Jul 2017, volume: 34, issue:4, pages: 80 - 106
Publisher: IEEE
 
» Image Recovery for Electrical Capacitance Tomography Based on Low-Rank Decomposition
Abstract:
Images reconstructed by an existing image reconstruction algorithm for electrical capacitance tomography (ECT) are usually blurred or corrupted due to data noise. To recover the missing or corrupted pixels in the images, an approach to robustly reconstruct images based on low-rank decomposition is presented for ECT. With this approach, recovering the permittivity distribution is recast as one of recovering low-rank matrix from corrupted images. A convex optimization technique is used to obtain the correct low-rank matrix and the error matrix. Experimental results show the effectiveness of the proposed method. Furthermore, the simplified optimization method is fast and could be used for online imaging. The method can also be used in other tomographic techniques.
Autors: Jiamin Ye;Haigang Wang;Wuqiang Yang;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1751 - 1759
Publisher: IEEE
 
» Image-Based Biophysical Simulation of Intracardiac Abnormal Ventricular Electrograms
Abstract:
Goal: In this paper, we used in silico patient-specific models constructed from three-dimensional delayed-enhanced magnetic resonance imaging (DE-MRI) to simulate intracardiac electrograms (EGM). These included electrically abnormal EGM as these are potential radiofrequency ablation (RFA) targets. Methods: We generated signals with distinguishable macroscopic normal and abnormal characteristics by constructing MRI-based patient-specific structural heart models and by solving the simplified biophysical Mitchell–Schaeffer model of cardiac electrophysiology (EP). Then, we simulated intracardiac EGM by modeling a recording catheter using a dipole approach. Results: Qualitative results show that simulated EGM resemble clinical signals. Additionally, the quantitative assessment of signal features extracted from the simulated EGM showed statistically significant differences (p 0.0001) between the distributions of normal and abnormal EGM, similarly to what is observed on clinical data. Conclusion: We demonstrate the feasibility of coupling simplified cardiac EP models with imaging data to generate intracardiac EMG. Significance: These results are a step forward in the direction of the preoperative and noninvasive identification of ablation targets to guide RFA therapy.
Autors: Rocío Cabrera-Lozoya;Benjamin Berte;Hubert Cochet;Pierre Jaïs;Nicholas Ayache;Maxime Sermesant;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jul 2017, volume: 64, issue:7, pages: 1446 - 1454
Publisher: IEEE
 
» Imaging the Impact of Proton Irradiation on Edge Terminations in Vertical GaN PIN Diodes
Abstract:
Devices based on GaN have shown great promise for high power electronics, including their potential use as radiation tolerant components. An important step to realizing high power diodes is the design and implementation of an edge termination to mitigate field crowding, which can lead to premature breakdown. However, little is known about the effects of radiation on edge termination functionality. We experimentally examine the effects of proton irradiation on multiple field ring edge terminations in high power vertical GaN PIN diodes using in operando imaging with electron beam induced current (EBIC). We find that exposure to proton irradiation influences field spreading in the edge termination as well as carrier transport near the anode. By using depth-dependent EBIC measurements of hole diffusion length in homoepitaxial n-GaN we demonstrate that the carrier transport effect is due to a reduction in hole diffusion length following proton irradiation.
Autors: K. C. Collins;M. P. King;J. R. Dickerson;G. Vizkelethy;A. M. Armstrong;A. J. Fischer;A. A. Allerman;R. J. Kaplar;O. Aktas;I. C. Kizilyalli;A. A. Talin;F. Léonard;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2017, volume: 38, issue:7, pages: 945 - 948
Publisher: IEEE
 
» Immediate Neighborhood Temperature Adaptive Routing for Dynamically Throttled 3-D Networks-on-Chip
Abstract:
In this brief, we present the immediate neighborhood temperature (INT) routing algorithm, which balances thermal profiles across dynamically throttled 3-D networks-on-chip by adaptively routing interconnect traffic based on runtime temperature monitoring. INT avoids the overheads of system-wide temperature monitoring by relying on the heat transfer characteristics of 3-D integrated circuits that enable temperature information from routers in the immediate neighborhood to guide adaptive routing decisions. Experimental results indicate that INT yields balanced thermal profiles with up to 25% lower gradients than competing schemes and shortens communication latency by decreasing average network congestion by up to 50%, with negligible overheads.
Autors: Sumeet S. Kumar;Amir Zjajo;Rene van Leuken;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jul 2017, volume: 64, issue:7, pages: 782 - 786
Publisher: IEEE
 
» Impact and Design Guideline of Monolithic 3-D IC at the 7-nm Technology Node
Abstract:
Monolithic 3-D (M3D) IC is one of the potential technologies to break through the challenges of continued circuit power and performance scaling. In this paper, for the first time, we demonstrate the power benefits of M3D and present design guideline in a 7-nm FinFET technology node. The predictive 7-nm process design kit (PDK) and the standard cell library using both high-performance (HP) and low-standby-power (LSTP) device technologies are developed based on NanGate 45-nm PDK using accurate dimensional, material, and electrical parameters from publications and a commercial-grade tool flow. We implement full-chip M3D designs utilizing industry-standard physical design tools, and gauge the impact of M3D technology on performance, power, and area metrics. We also provide the design guidelines as well as a new partitioning methodology to improve M3D design quality. This paper shows that M3D designs outperform 2-D counterparts by 16% and 16.5% on average in terms of isoperformance total power reduction with 7-nm HP and LSTP cell library, respectively. This demonstrates the power benefits of M3D technology in both HP and low-power future generation devices.
Autors: Kyungwook Chang;Kartik Acharya;Saurabh Sinha;Brian Cline;Greg Yeric;Sung Kyu Lim;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jul 2017, volume: 25, issue:7, pages: 2118 - 2129
Publisher: IEEE
 
» Impact of an IR-UWB Reading Approach on Chipless RFID Tag
Abstract:
An unusual configuration for chipless radio frequency identification reader based on impulse radio ultrawideband is proposed. The impact of this approach on chipless tag reading performance, compared with the frequency modulated continuous-wave technique, is studied. By reducing the inner sampling clock jitter of the proposed reader, it is possible to have resolution compared with laboratory equipment.
Autors: Marco Garbati;Romain Siragusa;Etienne Perret;Christophe Halopé;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jul 2017, volume: 27, issue:7, pages: 678 - 680
Publisher: IEEE
 
» Impact of Coupled Transmission-Distribution on Static Voltage Stability Assessment
Abstract:
With the rapid growth of distributed generators, the distribution static voltage stability assessment (D-VSA) becomes as important as the transmission voltage stability assessment (T-VSA). However, the T-VSA and D-VSA normally treat the transmission and distribution separately, neglecting the interactions between transmission and distribution (T-D). This letter studies the impact of coupled T-D on VSA via physical analysis and numerical simulation. We observe that without considering the T-D interaction, D-VSA may exaggerate the actual load margin significantly, and T-VSA may either exaggerate or underestimate the actual load margin, both of which are unreliable. Hence, the coupled T-D interactions must be considered in both T-VSA and D-VSA.
Autors: Zhengshuo Li;Qinglai Guo;Hongbin Sun;Jianhui Wang;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 3311 - 3312
Publisher: IEEE
 
» Impact of Driving Behavior on Traffic Delay at a Congested Signalized Intersection
Abstract:
This paper proposes a methodology to categorize drivers’ behaviors at a congested signalized intersection. As a discrete event system model, timed Petri nets (TPNs) are used in this paper to formally define two kinds of behaviors: non-jam-induced driving behavior and jam-induced one. In order to systematically assess the performances of both behaviors, a new urban traffic network model is built: a cell transmission model is used to depict the road link traffic that is consistent with the kinematic property of traffic flow, and TPNs are used to model the behaviors and the conflicting traffic flow at the intersection. Some simulation results are given to evaluate the impact of driving behavior on the traffic delay.
Autors: Liang Qi;MengChu Zhou;WenJing Luan;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jul 2017, volume: 18, issue:7, pages: 1882 - 1893
Publisher: IEEE
 
» Impact of FWM on the Performance of 2-D Time-Wavelength OCDMA Systems
Abstract:
A derivation of a general formula for the bit error rate of 2-D time-spreading wavelength-hopping optical code division multiple access systems under the impact of four-wave mixing (FWM) is presented. The effect of many system parameters such as the transmitted power per chip, code properties, wavelength spacing, and transmission fiber length is investigated. The analysis reveals that the generated FWM light contributes not only as an additional crosstalk component, but also produces as extra three noise terms, namely, signal-FWM, interferer-FWM, and FWM-FWM noise. Theoretical results show the detrimental effect of FWM on the system performance at high chip power levels; resulting in a 4-dB penalty at a power of 15 dBm. Furthermore, the paper presents many aspects useful in the system design.
Autors: Taher M. Bazan;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 2846 - 2852
Publisher: IEEE
 
» Impact of Gate–Drain Spacing on Low-Frequency Noise Performance of In Situ SiN Passivated InAlGaN/GaN MIS-HEMTs
Abstract:
In this paper we investigated the gate–drain access region spacing ( effect on electrical and noise performance of InAlGaN/GaN metal–insulator–semiconductor high electron mobility transistors (MIS-HEMTs) using in situ SiN cap layer as gate insulator. Different of InAlGaN/GaN MIS-HEMTs using sub-10 nm barrier layer are studied. Low-frequency noise measurements have been carried out for the first time in order to analyze the impact of the gate–drain spacing on the electrical characteristics. The noise of the channel under the gate has been identified as the dominant channel noise source for . Finally, the calculated Hooge parameter ( is equal to . It reflects the high material quality while using sub-10 nm InAlGaN layer, which is promising for high-frequency applications.
Autors: Mehdi Rzin;Jean-Marc Routoure;Bruno Guillet;Laurence Méchin;Magali Morales;Cédric Lacam;Piero Gamarra;Pierre Ruterana;Farid Medjdoub;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2017, volume: 64, issue:7, pages: 2820 - 2825
Publisher: IEEE
 
» Impact of Multi-terminal HVDC Grids on Enhancing Dynamic Power Transfer Capability
Abstract:
This paper proposes the exploitation of multiterminal HVDC grids to improve transfer capability in power systems. Multiterminal HVDC systems based on voltage source converters (VSC-MTDC) have been recognized as a promising alternative for the wind power integration. Under low wind scenarios, these grids originally dedicated for wind power transmission can be exploited as an additional interarea transmission path, providing extra dynamic security. The paper focuses on small-signal stability assessment, especially in poor damped oscillations associated with interarea modes. Simulations performed through a generic computational framework have shown that the high level of flexibility and controllability provided by voltage source converters can considerably improve the transfer capacity, while preserving adequate dynamic performance.
Autors: Tatiana Mariano Lessa Assis;Stefanie Kuenzel;Bikash Chandra Pal;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 2652 - 2662
Publisher: IEEE
 
» Impact of Plant Surface Moisture on Differential Interferometric Observables: A Controlled Electromagnetic Experiment
Abstract:
The estimation of soil moisture and crop biomass based on differential interferometry is questioned by the influence of intercepted rain (i.e., plant surface moisture) on repeat-pass observables. The magnitude, the origin of this effect, as well as its dependence on system and crop biophysical parameters have been only marginally addressed so far. This paper intends to investigate these aspects within the frame of a laboratory experiment carried out in a highly controlled electromagnetic environment. The collection of multifrequency and fully polarimetric scatterometer profiles offers a distinctive data set, which helps to understand the variations of the interferometric observables in response to a varying plant surface moisture. These changes are assessed by comparing the predictions of a first-order scattering solution with the impact found in the experimental data. Furthermore, the connection between plant surface moisture and differential interferometric observables (i.e., the magnitude and phase of the interferometric coherence) is empirically tested with the aid of regression techniques. Irrespective of frequency and polarization, intercepted water is found to impact the interferometric coherence in a similar way as changes in soil and/or plant water status, i.e., the increase of the sensor to target optical path. Changes of plant surface moisture might be erroneously mistaken either for soil water content or fresh biomass variations. Therefore, this paper raises the possibility that, in certain circumstances, intercepted water might represent a potential source of bias for the estimation of these two land surface parameters.
Autors: Virginia Brancato;Frank Liebisch;Irena Hajnsek;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jul 2017, volume: 55, issue:7, pages: 3949 - 3964
Publisher: IEEE
 
» Impact of Pointing Errors on the Error Performance of Intersatellite Laser Communications
Abstract:
The effect of pointing errors on the average bit error probability (ABEP) of an intersatellite laser communication link is studied. A closed-form expression in terms of the Marcum -function is given for calculating the instantaneous channel gain. This expression provides great potential in further performance analysis and system optimization. In addition, tight, closed-form upper and lower bounds on the ABEP are derived, by using bounds on the Gaussian -function. These bounds are in simpler form than existing results and are much more efficient in numerical evaluations. Further simplifications of these bounds are performed and invertible ABEP expressions are given. Via numerical comparisons, these invertible ABEP expressions are shown to be accurate approximations within a wide range of transmit power of interest and thus provide efficient error prediction methods. The diversity gain is easily obtained using the invertible ABEP expressions, which is related to the ratio of the equivalent beam radius to the pointing error displacement standard jitter at the receiver. Moreover, we show explicitly how the ABEP depends on different system parameters.
Autors: Tianyu Song;Qian Wang;Ming-Wei Wu;Tomoaki Ohtsuki;Mohan Gurusamy;Pooi-Yuen Kam;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 3082 - 3091
Publisher: IEEE
 
» Impact of Series Resistance on Bulk CMOS Current Matching Over the 5–300K Temperature Range
Abstract:
This letter presents the impact of source/drain series resistance on the matching of bulk nMOS and pMOS field-effect transistor current over the 5–300K temperature range. A new method to extract series resistance is introduced, and we show experimentally that current variations, considering series resistance, increase as temperature decreases. Moreover, we propose a new approach to calculate the current mismatch based on MOSFET parameters and series resistance. The approach predicts the current variation better than the conventional model over the examined temperatures.
Autors: Nguyen Cong Dao;Abdallah El Kass;Craig T. Jin;Philip H. W. Leong;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2017, volume: 38, issue:7, pages: 847 - 850
Publisher: IEEE
 
» Impact of Zero-Volt Loop Control on Efficiency of Switched Reluctance Motors
Abstract:
Zero-volt loop (ZVL) algorithms are known to be able to reduce peak flux linkages and resulting iron losses while keeping the same average torque in average torque control (ATC) of switched reluctance motors (SRMs). However, exploiting ZVLs to minimize the losses has been challenging due to the strongly nonlinear correlations between the torque and the control parameters of ATC caused by extensive magnetic saturation. In this paper, a fast optimization method for loss minimization is proposed, which can utilize all control parameters of ATC while operating with ZVL control. The proposed optimization method quickly calculates the current reference, which is one of the control parameters, so as to satisfy a torque reference, and consequently removes the time-consuming nonlinear constraint on the torque from conventional optimization methods. Using the proposed optimization method, the impact of ZVL control in loss minimization of SRMs is investigated with detailed simulations and experiments. The results verified that the utilization of ZVLs reduces iron losses without significantly increasing copper losses. It was found that the loss reduction was especially large (more than 15%) at medium speed and partial load. The loss reduction in the Japanese JC08 driving cycle for automotive propulsion for city driving was investigated and was as large as 15%. Furthermore, the vibrations that cause acoustic noise were also reduced.
Autors: Tetsuya Kojima;Rik W. De Doncker;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3621 - 3634
Publisher: IEEE
 
» Implementation of Echo-State Network-Based Control for Power Quality Improvement
Abstract:
This paper proposes a new control algorithm for mitigation of power quality problems at the distribution level. The control algorithm is designed on the basis of echo-state network, which is a type of recurrent neural network. This technique is used to extract fundamental weight components from nonsinusoidal load currents. These weight components are used to evaluate reference grid currents and consequently generate switching logic for the voltage source converter used in the active filter. The shunt-connected active filter with the proposed control algorithm is used to overcome several current-related power quality problems and provides the load compensation. Problems such as the presence of lower order harmonics, insufficient reactive power, and load unbalancing are corrected using a shunt filter in both the power factor correction and voltage regulation modes. The proposed control algorithm is validated on a real time system which is a prototype of a shunt filter. The algorithm is tested in MATLAB using Sim Power Systems and SIMULINK and implemented on a digital signal processor.
Autors: Manoj Badoni;Bhim Singh;Alka Singh;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5576 - 5584
Publisher: IEEE
 
» Improved Analytical Estimation of Rotor Losses in High-Speed Surface-Mounted PM Synchronous Machines
Abstract:
The prediction of rotor losses, primarily due to eddy currents (ECs) in either magnets or other rotor conductive parts, is of great concern for the design of surface-mounted permanent magnet synchronous machines. Particularly, in high-speed electrical machines, EC losses could be severe and seriously affect the machine performance in terms of thermal management and demagnetization, in turn influencing the efficiency. This paper proposes a novel and more comprehensive approach for analytically detecting rotor losses in such machines; broadening investigation techniques already well established by considering the slotting effect and its interaction with stator winding generated by magnetic field harmonics. Therefore, predicting the electromagnetic behavior of EC losses by means of the presented fast and accurate procedure represents a useful instrument for electromechanical designers to assess the machine performance.
Autors: Nicola Chiodetto;Nicola Bianchi;Luigi Alberti;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3548 - 3556
Publisher: IEEE
 
» Improved Lower Bounds for Coded Caching
Abstract:
Caching is often used in content delivery networks as a mechanism for reducing network traffic. Recently, the technique of coded caching was introduced whereby coding in the caches and coded transmission signals from the central server were considered. Prior results in this area demonstrate that carefully designing the placement of content in the caches and designing appropriate coded delivery signals from the server allow for a system where the delivery rates can be significantly smaller than conventional schemes. However, matching upper and lower bounds on the transmission rate have not yet been obtained. In this paper, we derive tighter lower bounds on the coded caching rate than were known previously. We demonstrate that this problem can equivalently be posed as a combinatorial problem of optimally labeling the leaves of a directed tree. Our proposed labeling algorithm allows for significantly improved lower bounds on the coded caching rate. Furthermore, we study certain structural properties of our algorithm that allow us to analytically quantify improvements on the rate lower bound for general values of the problem parameters. This allows us to obtain a multiplicative gap of at most four between the achievable rate and our lower bound.
Autors: Hooshang Ghasemi;Aditya Ramamoorthy;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jul 2017, volume: 63, issue:7, pages: 4388 - 4413
Publisher: IEEE
 
» Improving Registration Robustness for Image-Guided Liver Surgery in a Novel Human-to-Phantom Data Framework
Abstract:
In open image-guided liver surgery (IGLS), a sparse representation of the intraoperative organ surface can be acquired to drive image-to-physical registration. We hypothesize that uncharacterized error induced by variation in the collection patterns of organ surface data limits the accuracy and robustness of an IGLS registration. Clinical validation of such registration methods is challenged due to the difficulty in obtaining data representative of the true state of organ deformation. We propose a novel human-to-phantom validation framework that transforms surface collection patterns from in vivo IGLS procedures (n = 13) onto a well-characterized hepatic deformation phantom for the purpose of validating surface-driven, volumetric nonrigid registration methods. An important feature of the approach is that it centers on combining workflow-realistic data acquisition and surgical deformations that are appropriate in behavior and magnitude. Using the approach, we investigate volumetric target registration error (TRE) with both current rigid IGLS and our improved nonrigid registration methods. Additionally, we introduce a spatial data resampling approach to mitigate the workflow-sensitive sampling problem. Using our human-to-phantom approach, TRE after routine rigid registration was 10.9 ± 0.6 mm with a signed closest point distance associated with residual surface fit in the range of ±10 mm, highly representative of open liver resections. After applying our novel resampling strategy and improved deformation correction method, TRE was reduced by 51%, i.e., a TRE of 5.3 ± 0.5 mm. This paper reported herein realizes a novel tractable approach for the validation of image-to-physical registration methods and demonstrates promising results for our correction method.
Autors: Jarrod A. Collins;Jared A. Weis;Jon S. Heiselman;Logan W. Clements;Amber L. Simpson;William R. Jarnagin;Michael I. Miga;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jul 2017, volume: 36, issue:7, pages: 1502 - 1510
Publisher: IEEE
 
» Improving Spectral Efficiency of FBMC-OQAM Through Virtual Symbols
Abstract:
Filter bank multicarrier (FBMC) systems based on offset quadrature amplitude modulation (OQAM), namely FBMC-OQAM, have been criticized for their inefficiency in the use of spectral resources, because of the long ramp-up and ramp-down tails at the beginning and the end of each data packet, respectively. We propose a novel method for shortening these tails. By appending a set of virtual (i.e., none data carrying) symbols to the beginning and the end of each packet, and clever selection of these symbols, we show that the ramp-up and ramp-down tails in the FBMC-OQAM can be suppressed to the extent that they are deemed negligible and thus may be ignored. This shortens the length of signal burst in each FBMC-OQAM packet and improves its spectral efficiency, viz., the same data is transmitted over a shorter period of time. We develop an optimization method that allows computation of virtual symbols for each data packet. Simulation results show that, compared with the existing methods, the proposed tail-shortening approach leads to superior out-of-band emissions performance and a much lower error vector magnitude for the demodulated symbols.
Autors: Daiming Qu;Fang Wang;Yan Wang;Tao Jiang;Behrouz Farhang-Boroujeny;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jul 2017, volume: 16, issue:7, pages: 4204 - 4215
Publisher: IEEE
 
» Improving the Dimming Performance of Low-Power Single-Stage AC–DC HBLED Drivers
Abstract:
The design of efficient single-stage high-brightness light-emitting diodes (HBLEDs) ac–dc drivers with power factor correction (PFC) in low-power applications is addressed in this paper. The PFC is achieved by using a switching converter with both step-up and step-down voltage capability. It is well known that a good tracking of the input reference current close to the zero crossing is challenging, in particular when the LED output current is low, hence jeopardizing the power quality at low power levels. A solution is proposed to improve the power quality in ac–dc LED drivers under inner current loop based on a variable hysteresis modulation scheme. An adaptive hysteresis window modulated by the input voltage and the output LED current reference is used. The double modulation strategy helps to avoid the distortion near the zero crossings of the input current and to improve the dimming performance of the HBLEDs. This results in a low value of total harmonic distortion (THD) under low current/power conditions and therefore in a very good dimming performance in single-stage ac–dc HBLEDs drivers with PFC. The operation principle of the proposed technique is presented and numerical simulations are shown to demonstrate its functionality. A laboratory prototype is designed and tested to verify its feasibility obtaining a significant improvement in terms of power quality. Under universal input voltage operation, good efficiency and low THD can be achieved even for low power levels.
Autors: Mirko Bodetto;Abdelali El Aroudi;Angel Cid-Pastor;Mohammed S. Al-Numay;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5797 - 5806
Publisher: IEEE
 
» Improving the Performance of ZnO Thin-Film Transistors with ZnON Source/Drain Contacts
Abstract:
Motivation to study the ZnO channel for thin-film transistors (TFTs) is strong in light of its decent high mobility and large bandgap, enabling simultaneous coexistence of high on current and low off-state leakage. Nevertheless, the improvement in device performance for ZnO TFTs has not been fully exercised and even the field-effect mobility () is degraded with downscaling the channel length owing to considerable series source/drain (S/D) resistance (). In this paper, we show that inserting a thin contact layer of ZnON between the ZnO channel and Al S/D effectively suppresses the formation of interfacial layer of AlOx and thereby reduces dramatically. This is evidenced by a significant reduction in from 30.1 to 14.4 measured on 0.5- ZnO TFTs with a ZnON contact layer or not, leading to an improvement in from 18.2 to 29.6 cm.
Autors: Chin-I Kuan;Horng-Chih Lin;Pei-Wen Li;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2017, volume: 64, issue:7, pages: 2849 - 2853
Publisher: IEEE
 
» In-Phase and Quadrature Timing Mismatch Estimation and Compensation in Millimeter-Wave Communication Systems
Abstract:
The emerging millimeter-wave (mm-wave) MIMO systems are subject to strong radio frequency (RF) distortions and their compensation is crucial to realize such systems. In the existing literature, several estimation and compensation schemes have been proposed for RF distortions, such as carrier frequency offset, phase noise, and in-phase and quadrature amplitude and phase imbalance (IQI). However, in-phase and quadrature timing mismatch (IQTM) is largely ignored. This paper investigates the effect of the IQTM on mm-wave system performance and reveals that IQTM causes a specific image rejection ratio characteristic, which is substantially different from the regular frequency-dependent IQI and it substantially prolongs the effective channel length. If not compensated, the IQTM can degrade system performance significantly. As a solution to this IQTM problem, this paper proposes novel pilot designs for transmit and receive IQTM estimation, and develops corresponding estimators, transmission protocol, and compensation schemes. MIMO averaging is also proposed, which substantially enhances the IQTM estimation performance. Simulation results show that our proposed pilot designs and estimators offer an efficient solution to the IQTM problem.
Autors: Hlaing Minn;Qi Zhan;Naofal Al-Dhahir;Huang Huang;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jul 2017, volume: 16, issue:7, pages: 4317 - 4331
Publisher: IEEE
 
» Incremental Layer Assignment Driven by an External Signoff Timing Engine
Abstract:
Modern technologies provide wide and thick metal layers that must be wisely used to reduce the delay of critical interconnections. After global routing, incremental layer assignment can improve the circuit timing by properly selecting critical interconnect segments to be routed in the faster (but very limited) wires on upper layers. Existing techniques based on net-by-net iterative improvement may get stuck at locally-optimal solutions depending on net ordering. Recent techniques rule out such drawback through the simultaneous iterative improvement of all nets, but they unfortunately rely on objective functions that may guide the optimization off critical paths. As opposed to all reported techniques, which rely on simplified, overly pessimistic timing models, this paper proposes the decoupling of incremental layer assignment from the timing analysis and the exploitation of flow conservation conditions so as to enable the use of an external signoff timing engine. The novel technique was experimentally compared with two state-of-the art works, leading to 50% less timing violations under total negative slack metric and 35% less timing violations under worst negative slack metric with similar overhead in number of vias.
Autors: Vinicius Livramento;Derong Liu;Salim Chowdhury;Bei Yu;Xiaoqing Xu;David Z. Pan;José Luís Güntzel;Luiz C. V dos Santos;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jul 2017, volume: 36, issue:7, pages: 1126 - 1139
Publisher: IEEE
 
» Independent Vector Analysis Applied to Remove Muscle Artifacts in EEG Data
Abstract:
Electroencephalogram (EEG) data are often contaminated by various electrophysiological artifacts. Among all these artifacts, the muscle activity is particularly difficult to remove. In the literature, independent component analysis (ICA) and canonical correlation analysis (CCA), as blind source separation techniques, are the most popular methods. In this paper, we introduce a novel method for removing muscle artifacts in EEG data based on independent vector analysis. This method exploits both the second-order and higher order statistical information and thus takes advantage of both ICA and CCA. The proposed method is evaluated on realistic simulated data and is shown to significantly outperform ICA and CCA. In addition, the proposed method is applied on real ictal EEG data seriously contaminated with muscle artifacts. The proposed method is able to largely suppress muscle artifacts without altering the underlying EEG activity.
Autors: Xun Chen;Hu Peng;Fengqiong Yu;Kai Wang;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1770 - 1779
Publisher: IEEE
 
» Individual Secrecy for Broadcast Channels With Receiver Side Information
Abstract:
This paper studies the problem of secure communication over the broadcast channel with receiver-side information under the lens of individual secrecy constraints, that is, the transmitter wants to send two independent messages to two receivers, which have, respectively, the desired message of the other receiver as side information, while keeping the eavesdropper ignorant of each message (i.e., the information leakage rate from each message to the eavesdropper is made vanishing). Building upon one-time pad, secrecy coding, and broadcasting schemes, achievable rate regions are investigated, and the capacity region for special cases of either a weak or strong eavesdropper (compared to both legitimate receivers) is characterized. Interestingly, the capacity region for the former corresponds to a line and the latter corresponds to a rectangle with missing corners; a phenomenon occurring due to the coupling between user’s rates. Moreover, the individual secrecy capacity region is also fully characterized for the case where the eavesdropper’s channel is deterministic. In addition to discrete memoryless setup, Gaussian scenarios are studied. For the Gaussian model, in addition to the strong and weak eavesdropper cases, the capacity region is characterized for the low and high SNR regimes when the eavesdropper’s channel is stronger than one receiver but weaker than the other. Remarkably, positive secure transmission rates are always guaranteed under the individual secrecy constraint, unlike the case of the joint secrecy constraint (i.e., the information leakage rate from both messages to the eavesdropper is made vanishing). Thus, this notion of secrecy serves as an appropriate candidate for trading off secrecy level and transmission rate, making secrecy more affordable but still ac- eptable to the end user.
Autors: Yanling Chen;O. Ozan Koyluoglu;Aydin Sezgin;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jul 2017, volume: 63, issue:7, pages: 4687 - 4708
Publisher: IEEE
 
» Indoor Localization and Automatic Fingerprint Update with Altered AP Signals
Abstract:
Wi-Fi fingerprinting has been extensively studied for indoor localization due to its deployability under pervasive indoor WLAN. As the signals from access points (APs) may change due to, for example, AP movement or power adjustment, the traditional approach is to conduct site survey regularly in order to maintain localization accuracy, which is costly and time-consuming. Here, we study how to accurately locate a target and automatically update fingerprints in the presence of altered AP signals (or simply, “altered APs”). We propose Localization with Altered APs and Fingerprint Updating (LAAFU) system, employing implicit crowdsourced signals for fingerprint update and survey reduction. Using novel subset sampling, LAAFU identifies any altered APs and filter them out before a location decision is made, hence maintaining localization accuracy under altered AP signals. With client locations anywhere in the region, fingerprint signals can be adaptively and transparently updated using non-parametric Gaussian process regression. We have conducted extensive experiments in our campus hall, an international airport, and a premium shopping mall. Compared with traditional weighted nearest neighbors and probabilistic algorithms, results show that LAAFU is robust against altered APs, achieving 20 percent localization error reduction with the fingerprints adaptive to environmental signal changes.
Autors: Suining He;Wenbin Lin;S.-H. Gary Chan;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jul 2017, volume: 16, issue:7, pages: 1897 - 1910
Publisher: IEEE
 
» Inferring Emotional Tags From Social Images With User Demographics
Abstract:
Social images, which are images uploaded and shared on social networks, are used to express users’ emotions. Inferring emotional tags from social images is of great importance; it can benefit many applications, such as image retrieval and recommendation. Whereas previous related research has primarily focused on exploring image visual features, we aim to address this problem by studying whether user demographics make a difference regarding users’ emotional tags of social images. We first consider how to model the emotions of social images. Then, we investigate how user demographics, such as gender, marital status, and occupation, are related to the emotional tags of social images. A partially labeled factor graph model named the demographics factor graph model (D-FGM ) is proposed to leverage the uncovered patterns. Experiments on a data set collected from the world's largest image sharing website Flickr1

[Online]. Available: http://www.flickr.com/

confirm the accuracy of the proposed model. We also find some interesting phenomena. For example, men and women have different patterns to tag “anger” for social images.
Autors: Boya Wu;Jia Jia;Yang Yang;Peijun Zhao;Jie Tang;Qi Tian;
Appeared in: IEEE Transactions on Multimedia
Publication date: Jul 2017, volume: 19, issue:7, pages: 1670 - 1684
Publisher: IEEE
 
» Influence of External Conductive Objects on the Performance of an Ironless Inductive Position Sensor
Abstract:
The ironless inductive position sensor (I2PS) is a novel device that measures high-precision linear position without being affected by radiation and external magnetic fields. Built on the basis of the linear variable differential transformer, the I2PS senses the variation of flux linkage between the supply and sense coils which is related to the linear position of the moving coil. This paper characterizes the magnetic performance of the I2PS through a detailed analysis of the impact of axisymmetrical external conductive objects on the sensor. This characterization is performed through a set of finite element simulations and through dedicated experiments. Axisymmetrical conductive objects result in offset voltages, but the differential measurement techniques combined with high-resolution calibration curves mitigate this effect.
Autors: Adrian Grima;Alessandro Danisi;Alessandro Masi;Nicholas Sammut;
Appeared in: IEEE Sensors Journal
Publication date: Jul 2017, volume: 17, issue:14, pages: 4500 - 4507
Publisher: IEEE
 
» Influence of Manufacturing Tolerances on Cogging Torque in Interior Permanent Magnet Machines with Eccentric and Sinusoidal Rotor Contours
Abstract:
Rotor shaping methods are frequently used to reduce the cogging torque in interior permanent magnet (IPM) machines. This paper investigates the influence of manufacturing tolerances on cogging torque in IPM machines with eccentric and sinusoidal rotor contours. First, two 12-slot/8-pole IPM machine models are established and the fundamental performance under ideal conditions is presented. Then, based on the most sensitive distributions of nonideal PMs and assembly tooth-bulges, additional cogging torque components are calculated, respectively, together with a comparative study to identify the different sensitivities between the two rotor contour designs. For verification, the field spatial harmonics with and without considering the tolerances are further analyzed, followed by tests on the prototypes with and without amplified tolerances.
Autors: Xiao Ge;Z. Q. Zhu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3568 - 3578
Publisher: IEEE
 
» Influence of Rotor-Pole Number on Electromagnetic Performance in 12-Phase Redundant Switched Flux Permanent Magnet Machines for Wind Power Generation
Abstract:
In this paper, electromagnetic performances of 12-phase 24-stator-pole redundant switched flux permanent magnet (SFPM) machines with 20-, 22-, 26-, and 28-rotor-pole rotors designed for wind power generation are comparatively analyzed. The influence of key design parameters on the open-circuit phase electromotive force and cogging torque is comparatively evaluated by a 2-D finite-element analysis (FEA). FEA results show that the 24-/26-pole SFPM machine exhibits the highest electromagnetic torque and efficiency than the other three, while the 24-/22-pole one has the smallest cogging torque and torque ripple as well as relatively good voltage regulation and efficiency, which are essential for a wind generator. Furthermore, the investigation on redundancy performance shows that cross coupling among the four sets of three-phase balanced windings and the saturation effect can be neglected when the generator operates with relative light loads. Finally, the 12-phase 24-/22-pole SFPM machine is built and tested to validate the simulations.
Autors: Lingyun Shao;Wei Hua;Z. Q. Zhu;Minghao Tong;Guishu Zhao;Fangbo Yin;Zhongze Wu;Ming Cheng;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3305 - 3316
Publisher: IEEE
 
» Influence of Sea State and Tidal Height on Wave Power Absorption
Abstract:
The wave energy converter developed at Uppsala University (Uppsala, Sweden) consists of a linear generator placed on the seabed and driven by the motion of a buoy on the water surface. The buoy is connected to the moving part of the linear generator, the translator, which is made of ferrite magnets. The translator moves vertically inducing voltage in the windings of a fixed component, the so-called stator. The energy conversion of the linear generator is affected by the sea state and by variations of mean sea level. The sea state influences the speed and the stroke length of the translator, while the variation of tidal level shifts the average position of the translator with respect to the center of the stator. The aim of this study is to evaluate the energy absorption of the wave energy converter at different locations around the world. This goal is achieved by developing a hydromechanic model which analyses the optimum generator damping factor for different wave climates and the power absorbed by the generator, given a fixed geometry of the buoy and a fixed stroke length of the translator. Economic considerations regarding the optimization of the damping factor are included within the paper. The results suggest a nominal damping factor and show the power absorption losses at various locations, each of them characterized by a different wave climate and tidal range. The power losses reach up to 67% and in many locations a tidal compensation system, included in the design of the wave energy converter, is strongly motivated.
Autors: Valeria Castellucci;Jessica García-Terán;Mikael Eriksson;Laurence Padman;Rafael Waters;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Jul 2017, volume: 42, issue:3, pages: 566 - 573
Publisher: IEEE
 
» Information Capacity of Polarization-Modulated and Directly Detected Optical Systems Dominated by Amplified Spontaneous Emission Noise
Abstract:
We derive the closed-form information capacity of optically amplified polarization modulation with direct detection and show that it exceeds a tight lower bound for the capacity of three parallel intensity modulated direct detection systems.
Autors: Hamid Khodakarami;Di Che;William Shieh;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 2797 - 2802
Publisher: IEEE
 
» Injurious or Noninjurious Defect Identification From MFL Images in Pipeline Inspection Using Convolutional Neural Network
Abstract:
This paper proposes an injurious or noninjurious defect identification method from magnetic flux leakage (MFL) images based on convolutional neural network. Different from previous approaches, this method is fed by the MFL images instead of the features of the MFL measurements, and thus it can skip the procedure of feature extraction. Moreover, for convenience, a normalization layer is added to the front of model. In the convolution layers, the rectified linear units are employed as the activation functions to shorten the training period and improve the performance. In addition, two local response normalization layers are also embedded into the proposed structure. We demonstrate the performance of the proposed model using real MFL data collected from experimental pipelines. Benefited from the special structure of the proposed model, this method is robust for shift, scale, and distortion variances of input MFL images. We also present a comparative result of the proposed model and other methods. The results prove that the proposed method can achieve higher accuracy than the traditional approaches.
Autors: Jian Feng;Fangming Li;Senxiang Lu;Jinhai Liu;Dazhong Ma;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1883 - 1892
Publisher: IEEE
 
» Innovations Powered by Signal Processing [From the Editor]
Abstract:
Presents the introductory editorial for this issue of the publication.
Autors: Min Wu;
Appeared in: IEEE Signal Processing Magazine
Publication date: Jul 2017, volume: 34, issue:4, pages: 3 - 9
Publisher: IEEE
 
» Innovative Sensors Promise Longer and Healthier Lives: Signal processing leads to devices that provide faster and more insightful monitoring and diagnoses [Special Reports]
Abstract:
Reports on new and innovative sensor technologies for the health care market.The health-care and medical applications sensor market is projected to expand at a compound annual growth rate of 13.1% between 2016 and 2022, according to a report issued in March 2017 by the research firm Frost & Sullivan. A key factor driving sensor sales is the growing availability of consumer and clinical devices that use sensor technology to diagnose, monitor, and track disease and fitness. Within the next few years, an emerging generation of smaller, less expensive, and highly sophisticated sensors will find their way into a wide range of personal and professional devices. With more patient care moving out of hospitals, the use of sensor-enabled home diagnostic and monitoring devices is expected to soar, the report notes. The market for sensors used in wearable health and fitness devices is also poised to grow rapidly.
Autors: John Edwards;
Appeared in: IEEE Signal Processing Magazine
Publication date: Jul 2017, volume: 34, issue:4, pages: 14 - 17
Publisher: IEEE
 
» Input-Current-Ripple-Free Two-Channel LED Driver
Abstract:
In this paper, an input-current-ripple-free two-channel light-emitting diode (LED) driver is presented. In the proposed LED driver, a current-sharing capacitor is integrated into the boost converter to achieve the current-sharing among the LEDs and to enhance the output voltage gain. Moreover, an input current ripple cancellation circuit is employed to eliminate the input current ripple. Finally, the operating principle, analysis, and experimental results are provided to verify the effectiveness of the proposed LED driver.
Autors: Kuo-Ing Hwu;Wen-Zhuang Jiang;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5865 - 5874
Publisher: IEEE
 
» Insights Into Phase-Noise Scaling in Switch-Coupled Multi-Core LC VCOs for E-Band Adaptive Modulation Links
Abstract:
High-capacity wireless links at millimeter-Waves are candidate for backhaul infrastructure to small-cell mobile networks. However, the use of high-order modulation schemes sets challenging phase-noise specifications for integrated frequency synthesizers. Moreover, the use of adaptive modulation suggests local oscillators exploiting noise scaling, up to several decibel depending on channel conditions. In this paper, multi-core switch-coupled LC voltage-controlled oscillators are proposed to achieve ultra-low phase noise and scalable noise performance according to system requirements in a power-efficient way. A theoretical model investigating the effect of LC core component mismatches shows very good agreement with experiments. Design insights are provided, key in order to take effective advantage from the proposed low-noise technique. A quad-core ~20 GHz oscillator prototype, followed by a frequency quadrupler, has been realized in 55-nm BiCMOS technology. Measured performances are ~70-to-81 GHz frequency range with −106.5-dBc/Hz minimum phase noise at 1-MHz offset from an 80-GHz carrier with 50-mW power consumption and 1.2-V supply. To authors’ knowledge, this is the lowest phase noise measured in the E-Band using integrated technologies and CMOS-compatible supplies. When noise requirements are relaxed, auxiliary cores are turned off rising phase noise by 6 dB but with power consumption reduced down to 18 mW only.
Autors: Lorenzo Iotti;Andrea Mazzanti;Francesco Svelto;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2017, volume: 52, issue:7, pages: 1703 - 1718
Publisher: IEEE
 
» Inspired by History [Memoirs]
Abstract:
Discusses how historical events have impacted the engineering career of the author. Also discusses the activities of the IEEE Industry Applications Society has been active in improving engineering technologies and applications.
Autors: Barry Brusso;
Appeared in: IEEE Industry Applications Magazine
Publication date: Jul 2017, volume: 23, issue:4, pages: 92 - 92
Publisher: IEEE
 
» Instant Object Detection in Lidar Point Clouds
Abstract:
In this letter, we present a new approach for object classification in continuously streamed Lidar point clouds collected from urban areas. The input of our framework is raw 3-D point cloud sequences captured by a Velodyne HDL-64 Lidar, and we aim to extract all vehicles and pedestrians in the neighborhood of the moving sensor. We propose a complete pipeline developed especially for distinguishing outdoor 3-D urban objects. First, we segment the point cloud into regions of ground, short objects (i.e., low foreground), and tall objects (high foreground). Then, using our novel two-layer grid structure, we perform efficient connected component analysis on the foreground regions, for producing distinct groups of points, which represent different urban objects. Next, we create depth images from the object candidates, and apply an appearance-based preliminary classification by a convolutional neural network. Finally, we refine the classification with contextual features considering the possible expected scene topologies. We tested our algorithm in real Lidar measurements, containing 1485 objects captured from different urban scenarios.
Autors: Attila Börcs;Balázs Nagy;Csaba Benedek;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jul 2017, volume: 14, issue:7, pages: 992 - 996
Publisher: IEEE
 
» Instrument Learning and Sparse NMD for Automatic Polyphonic Music Transcription
Abstract:
In this paper, an automatic music transcription (AMT) algorithm based on a supervised non-negative matrix decomposition (NMD) is discussed. In particular, a novel approach for enhancing the sparsity of the solution is proposed. It consists of a two-step processing in which the NMD is solved joining a regularization and a threshold filtering. In the first step, the NMD is performed with the regularization in order to get an overall selection of the notes most likely appearing in the monotimbral musical excerpt. In the second step, a threshold filtering followed by another regularized NMD are repeatedly performed in order to progressively reduce the dictionary matrix and to refine the notes transcription. Furthermore, a user-oriented instrument learning procedure has been conceived and proposed. The proposed AMT system has been tested upon the dataset collected by the LabROSA laboratories considering the transcription of three different pianos. Moreover, it has been validated through a comparison with a regularized NMD and with three open source AMT software. The results prove the effectiveness of the proposed two-step processing in enhancing the sparsity of the solution and in improving the transcription accuracy. Moreover, the proposed system shows promising performance in both multi-F0 and note tracking tasks, obtaining better transcription accuracy than the competing algorithms in most tests.
Autors: Antonello Rizzi;Mario Antonelli;Massimiliano Luzi;
Appeared in: IEEE Transactions on Multimedia
Publication date: Jul 2017, volume: 19, issue:7, pages: 1405 - 1415
Publisher: IEEE
 
» Insulator Infrared Image Denoising Method Based on Wavelet Generic Gaussian Distribution and MAP Estimation
Abstract:
The infrared techniques on failure detection in power grid have attracted widely attention in recent years. Since the infrared image of the insulator string has high noise and low contrast, it will affect the judgment accuracy of the zero value insulators. This paper proposes a method based on wavelet generic Gaussian and maximum posterior probability estimation for the noise removing of insulator infrared images. Due to the sharp peak and long tails features of the wavelet coefficients of the infrared images, generalized Gaussian distribution (GGD) is used as the probability distribution function. Maximum posterior probability estimation is used to obtain denoised signal from the posterior probability distribution function. Because the resolution of the maximum posterior probability estimation based on GGD cannot be achieved directly, Newton–Raphson law is used to obtain the resolution of the real signal wavelet coefficients. Compared by signal noise ratio and mean square error, the results indicate that the proposed method can effectively remove the infrared image noise and the performance is much better than the wavelet soft threshold method and wavelet hard threshold method.
Autors: Hongying He;Wei-Jen Lee;DianSheng Luo;Yijia Cao;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3279 - 3284
Publisher: IEEE
 
» Integrated Microstrip Meander Line Traveling Wave Tube Based on Metamaterial Absorber
Abstract:
An integrated microstrip meander line (MML) slow-wave structure (SWS) comprised of an MML SWS and compact wideband metamaterial absorber (MMA) is proposed and demonstrated theoretically and experimentally in this paper. The MMA consists of metallic rectangular resonators with a metallic ground plane and a separating dielectric layer. Simulation results show that the MMA has multidistinctive absorption peaks; the bandwidth at 56-GHz peak frequency is reach up to 30 GHz. The integrated MML SWS can provide flatter gain response of output power than that made by the MML SWS with a traditional resistive coating attenuator. Experimental results are in close agreement with simulation results. A traveling wave tube (TWT) is simulated based on this integrated MML SWS. The output power of this TWT is 48.21 W at 33 GHz corresponding to a maximum gain of 30.3 dB; the output power gain is greater than 25 dB across the entire working frequency range.
Autors: Ningfeng Bai;Cheng Feng;Yuntao Liu;Hehong Fan;Changsheng Shen;Xiaohan Sun;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2017, volume: 64, issue:7, pages: 2949 - 2954
Publisher: IEEE
 
» Integrated Multiple-Output Synchronous Buck Converter for Electric Vehicle Power Supply
Abstract:
This paper proposes a novel integrated synchronous buck converter for the auxiliary power supply system of electric vehicles, which achieves multiple independently regulated outputs with reduced switching components in comparison with the conventional separate buck converters. In order to obtain a better understanding of the proposed converter, operational principle and performance characteristics of a simplified dual-output buck converter are introduced in detail, as an example. The analysis shows that zero-voltage-switching operation and lower conduction losses could be attained. In addition, its dynamic behavior is similar to the conventional buck converter and thus the controller design is simple. Finally, experimental results based on a prototype circuit in which two inductors are integrated into one magnetic core to achieve further reduced cost are demonstrated to verify the advantages.
Autors: Guipeng Chen;Yan Deng;Jie Dong;Yihua Hu;Lin Jiang;Xiangning He;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 5752 - 5761
Publisher: IEEE
 
» Integrated Systems for Biomedical Applications: Silicon-Based RF\/Microwave Dielectric Spectroscopy and Sensing
Abstract:
Due to their use in the medical, biomedical, and nutritional fields, microwave dielectric sensors and spectroscopy systems are very good candidates for a variety of fields, including health care, food and drug safety, medical diagnosis, and agricultural and pharmaceutical applications. Dielectric sensors for such applications require fully integrated and self-sustained sensor implementations to achieve low-cost, compact, easy-to-handle products. Fully integrated dielectric sensors are promising (but also pose challenges) in terms of achieving size and cost reduction, low power consumption, enormous signal processing capabilities, and high throughput for portable, implantable, and lab-onchip applications. Integrated sensors can be either VCO-based, known for higher sensitivity and self-sustainability but not suitable for spectroscopy; or receiver-based, known to be more compatible with spectroscopy applications but with accuracy limited by the receiver's SNR performance. Given the challenges and design requirements for fully integrated dielectric sensors and spectroscopy systems, in this article we have summarized recently reported studies in the literature and shown in detail the advantages and disadvantages of each by comparing the different techniques.
Autors: Kamran Entesari;Ahmed A. Helmy;Masoud Moslehi-Bajestan;
Appeared in: IEEE Microwave Magazine
Publication date: Jul 2017, volume: 18, issue:5, pages: 57 - 72
Publisher: IEEE
 
» Integrated Terahertz Communication With Reflectors for 5G Small-Cell Networks
Abstract:
As the cellular networks continue to progress between generations, the expectations of 5G systems are planned toward high-capacity communication links that can provide users access to numerous types of applications (e.g., augmented reality and holographic multimedia streaming). The demand for higher bandwidth has led the research community to investigate unexplored frequency spectrums, such as the terahertz band for 5G. However, this particular spectrum is strived with numerous challenges, which includes the need for line-of-sight (LoS) links as reflections will deflect the waves as well as molecular absorption that can affect the signal strength. This is further amplified when a high quality of service has to be maintained over infrastructure that supports mobility, as users (or groups of users) migrate between locations, requiring frequent handover for roaming. In this paper, the concept of mirror-assisted wireless coverage is introduced, where smart antennas are utilized with dielectric mirrors that act as reflectors for the terahertz waves. The objective is to utilize information such as the user's location and to direct the reflective beam toward the highest concentration of users. A multiray model is presented in order to develop the propagation models for both indoor and outdoor scenarios in order to validate the proposed use of the reflectors. An office and a pedestrian-walking scenarios are used for indoor and outdoor scenarios, respectively. The results from the simulation work show an improvement with the usage of mirror-assisted wireless coverage, improving the overall capacity, the received power, the path loss, and the probability of LoS.
Autors: Michael Taynnan Barros;Robert Mullins;Sasitharan Balasubramaniam;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 5647 - 5657
Publisher: IEEE
 
» Integrating the Front End: A Highly Integrated RF Front End for High-SHF Wide-Band Massive MIMO in 5G
Abstract:
Fifth-generation (5G) mobile communications will need to accommodate huge traffic demands in the near future. Massive multipleinput/multiple-output (MIMO) technology utilizing hundreds of antenna elements has drawn attention as a key antenna configuration for envisioned 5G applications. Realizing the massive MIMO concept of active phased-array antennas (APAAs) for 5G will require small-size, low-power-consumption, and highly accurate phase control over the wide-band frequency range, which poses significant challenges for the RF front end. This article describes prototyped highly integrated RF front ends for high super-high-frequency (SHF) wide-band massive MIMO in 5G.
Autors: Shintaro Shinjo;Keigo Nakatani;Koji Tsutsumi;Hideyuki Nakamizo;
Appeared in: IEEE Microwave Magazine
Publication date: Jul 2017, volume: 18, issue:5, pages: 31 - 40
Publisher: IEEE
 

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