#### Electrical and Electronics Engineering publications abstract of: 09-2017 sorted by title, page: 1

» A High Slew-Rate Adaptive Biasing Hybrid Envelope Tracking Supply Modulator for LTE Applications
 Abstract:A linear-switch mode hybrid envelope tracking (ET) supply modulator utilizing adaptive biasing and gain enhanced current mirror operational transconductance amplifier (OTA) with class AB output stage in parallel with a switching regulator is presented. In comparison to a conventional OTA design with similar quiescent current consumption, proposed approach improves positive and negative slew rate from 50 to 93.4 V/ and −87 to −152.5 V/, respectively, dc gain from 45 to 67 dB while consuming same amount of quiescent current. The proposed hybrid supply modulator achieves 83% peak efficiency, power-added efficiency (PAE) of 42.3% at 26.2 dBm for a 10-MHz 7.24-dB peak-to-average power ratio (PAPR) long-term evolution (LTE) signal and improves PAE by 8% at 6 dB back off from 26.2-dBm power amplifier (PA) output power with respect to fixed supply. With a 10-MHz 7.24-dB PAPR quadrature-phase shift keying LTE signal the ET PA system achieves adjacent channel leakage ratio (ACLR) of −37.7 dBc and error vector magnitude (EVM) of 4.5% at 26.2-dBm PA output power, while with a 10-MHz 8.15-dB PAPR 64QAM LTE signal the ET PA system achieves ACLR of −35.6 dBc and EVM of 6% at 26-dBm PA output power without digital predistortion. The proposed supply modulator core circuit occupies 1.1-mm2 die area, and is fabricated in a 0.18- CMOS technology. Autors: Yue Jing;Bertan Bakkaloglu; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3245 - 3256 Publisher: IEEE
» A High-Consistency Broadband MEMS-Based Electrochemical Seismometer With Integrated Planar Microelectrodes
 Abstract:This paper presents a broadband micro-electromechanical systems-based electrochemical seismometer with a new sensing unit composed of planar microelectrodes and perpendicular flow channels. The proposed sensing unit only needs three main microfabrication steps, leading to high consistency among devices which was quantified as 0.9978 ± 0.00050. Moreover, due to the new structure of the propose sensing unit, the raw device was featured with higher sensitivity [215.5 V/(m/s)], lower central working frequency (1 Hz), and wider working bandwidth (0.12–10.5 Hz) than previous reports. Based on the wide raw bandwidth, a broadband electrochemical seismometer was developed by the force balancing negative feedback with the final working bandwidth of 4.2 decades (0.0071–113 Hz). The linearity error and total harmonic distortion were both decreased by the feedback technology. In addition, the proposed devices demonstrated comparable self-noise level with the high-performance commercial counterpart “Trillium Compact.” Random seismic recording test was also conducted where the proposed device recorded a local earthquake with high consistency with the STS-2.5 deployed in the permanent station. Autors: Zhenyuan Sun;Guanglei Li;Lianhong Chen;Deyong Chen;Junbo Wang;Jian Chen; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3829 - 3835 Publisher: IEEE
» A High-Frequency High-Power Test Bench for 11 MW/595 Hz Drives With 1.25 MW Grid Capability
 Abstract:This paper presents a pumpback test bench for high-frequency high-power variable-frequency drives (VFDs) with 11 MW power rating and up to 595 Hz load frequency. A voltage combiner concept is applied to allow a high-frequency output from the two three-level neutral-point-clamped integrated gate-commutated thyristor bridges with minimum switching losses. The accordingly developed pumpback test bench applies a dc power coupling concept combined with a virtual grid concept that can achieve 11 MW test capability with only a 1.25 MW facility transformer. By applying a virtual machine concept, the pumpback test can be conducted without the need of high-frequency machines, while the circulating power losses in the pumpback loop are minimized as well. The virtual grid including the concept tradeoff, filter parameters, and modulation schemes is presented in detail. Moreover, design and installation guidelines for high-frequency components, especially the cables, are presented. The high-frequency high-power VFD and its pumpback test bench are both successfully built and experimentally validated at their rated operation points. Autors: Jie Shen;Stefan Schröder;Bo Qu;Yingqi Zhang;Fan Zhang;Kunlun Chen;Richard Zhang; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4744 - 4756 Publisher: IEEE
» A High-Sensitivity Fiber Bragg Grating Displacement Sensor Based on Transverse Property of a Tensioned Optical Fiber Configuration and Its Dynamic Performance Improvement
 Abstract:This paper presents a high-sensitivity fiber Bragg grating (FBG) displacement sensor with a novel configuration for structural health monitoring. The transverse movement of an optical fiber that has been configured as a tight suspension status with its two ends fixed has been utilized to measure displacement. The theoretical models for both static and dynamic displacements have been derived. The corresponding simulations have been conducted to determine the relationship between the model parameters and the sensor performance. This approach supports the sensor design improvement and structural optimization. Two small working ranges have been selected to determine the simplified linear model according to Taylor series. The sensitivity of this sensor can reach up to 490.1 pm/mm with a high resolution of in a range of 1.4~2.0 mm. The introduction of the supporting spring unit has significantly enhanced the sensor’s resonant frequency without sacrificing the sensitivity. The application of the stiffer spring unit has enlarged the working bandwidth from 0~8 Hz to exceed 50 Hz. Enhancing the damping ratio unit can effectively improve the flatness of the dynamic response within the working bandwidth, while it does not affect other dynamic properties of the sensor. These improvements and design guidelines have been validated by both dynamic experiments and theoretical modeling. Autors: Tianliang Li;Yuegang Tan;Chaoyang Shi;Yongxing Guo;Zoran Najdovski;Hongliang Ren;Zude Zhou; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 5840 - 5848 Publisher: IEEE
» A High-Speed Efficient 220-GHz Spatial-Orthogonal ASK Transmitter in 130-nm SiGe BiCMOS
 Abstract:Wireless communication using terahertz/sub-terahertz band can alleviate the spectrum scarcity in conventional RF ands and satisfy the drastically expanding demands for capacity. In this paper, a spatial-orthogonal ASK transmitter architecture is presented. The self-sustaining oscillator-based transmitter architecture has an ultra-compact size and excellent power efficiency. With the proposed high-speed constant-load switch, significantly reduced modulation loss is achieved. Using polarization diversity and multi-level modulation, the throughput is largely enhanced. Array configuration is also adopted to enhance the link budget for higher signal quality and longer communication range. Fabricated in a 130-nm SiGe BiCMOS technology, the transmitter achieves an EIRP of 21 dBm and dc-to-THz-radiation efficiency of 0.7% in each spatial channel. A 24.4-Gb/s total data rate over a 10-cm communication range is demonstrated. With an external Teflon lens system, the demonstrated communication range is further extended to 52 cm. Compared with prior art, the proposed transmitter shows much higher power efficiency. Autors: Chen Jiang;Andreia Cathelin;Ehsan Afshari; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2321 - 2334 Publisher: IEEE
» A Humidity Sensor Based on a Singlemode-Side Polished Multimode–Singlemode Optical Fibre Structure Coated with Gelatin
 Abstract:A novel relative humidity sensor based on a singlemode-side polished multimode-singlemode fibre structure coated with gelatin material is reported. The sensing principle and fabrication method of the proposed sensor are presented. The experimental method is demonstrated to provide the optimum thickness of coating layers in order to achieve the highest sensitivity of 0.14 dB/%RH and a fast response time of 1000 ms for a given relative humidity sensing range. The developed humidity fibre optic sensor based on a gelatin coating shows great potential for many applications such as industrial production, food processing, and environmental monitoring. Autors: Xianfan Wang;Gerald Farrell;Elfed Lewis;Ke Tian;Libo Yuan;Pengfei Wang; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:18, pages: 4087 - 4094 Publisher: IEEE
» A Hybrid Approach for Near-Range Video Stabilization
 Abstract:Near-range videos contain objects that are close to the camera. These videos often contain discontinuous depth variation (DDV), which is the main challenge to the existing video stabilization methods. Traditionally, 2D methods are robust to various camera motions (e.g., quick rotation and zooming) under scenes with continuous depth variation (CDV). However, in the presence of DDV, they often generate wobbled results due to the limited ability of their 2D motion models. Alternatively, 3D methods are more robust in handling near-range videos. We show that, by compensating rotational motions and ignoring translational motions, near-range videos can be successfully stabilized by 3D methods without sacrificing the stability too much. However, it is time-consuming to reconstruct the 3D structures for the entire video and sometimes even impossible due to rapid camera motions. In this paper, we combine the advantages of 2D and 3D methods, yielding a hybrid approach that is robust to various camera motions and can handle the near-range scenarios well. To this end, we automatically partition the input video into CDV and DDV segments. Then, the 2D and 3D approaches are adopted for CDV and DDV clips, respectively. Finally, these segments are stitched seamlessly via a constrained optimization. We validate our method on a large variety of consumer videos. Autors: Shuaicheng Liu;Binhan Xu;Chuang Deng;Shuyuan Zhu;Bing Zeng;Moncef Gabbouj; Appeared in: IEEE Transactions on Circuits and Systems for Video Technology Publication date: Sep 2017, volume: 27, issue:9, pages: 1922 - 1933 Publisher: IEEE
» A Hybrid FETD-GSM Algorithm for Broadband Full-Wave Modeling of Resonant Waveguide Devices
 Abstract:An efficient hybrid algorithm that combines the finite-element time-domain (FETD) method with the generalized scattering matrix (GSM) technique is proposed to characterize the properties of wave propagation in highly resonant waveguide devices. To alleviate the problem of an extremely large number of time steps required for a highly resonant device, the algorithm first divides the device into several less resonant or resonant-free subdomains to reduce the number of time steps and the computational complexity of the FETD solver. The subdomain interfaces, which are assumed to be homogeneous, are modeled with an accurate waveguide port boundary condition (WPBC) to absorb any impinging waveguide modes. Each subdomain is then represented by a broadband GSM, which is computed by the fast Fourier transform of the FETD solutions. Finally, the subdomain GSMs are cascaded to form the global GSM of the original resonant device. The formulation and implementation of the FETD method with the WPBC, its required general waveguide modal analysis, and the cascading of GSMs are discussed in detail. Three numerical examples are presented to demonstrate the accuracy and efficiency of the proposed hybrid algorithm. Autors: Kedi Zhang;Chao-Fu Wang;Jian-Ming Jin; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3147 - 3158 Publisher: IEEE
» A Hybrid PWM-Based Field Weakening Strategy for a Hybrid-Inverter-Driven Open-Winding PMSM System
 Abstract:This paper proposes a hybrid pulse width modulation (PWM) based field weakening control strategy for a hybrid-inverter-driven open-winding (OW) permanent magnet synchronous motor (PMSM) system. The hybrid-inverter consists of two voltage source inverters, one is connected to a dc voltage source and named as main inverter (MI), and the other is connected to a floating capacitor and called compensation inverter (CI). A novel hybrid PWM technique is proposed for the hybrid-inverter, in which a double-vector-based PWM is applied to the MI to reduce the switching frequency, and the conventional space vector PWM is applied to the CI to compensate the reactive power. Furthermore, a field weakening (FW) control strategy based on the hybrid PWM technique is proposed to better utilize the dc-link voltage and extend the operation range of the OW-PMSM system. Simulation and experimental studies are carried out to verify the high efficiency and wide speed range of the proposed strategy. Autors: Dan Sun;Zhihao Zheng;Bin Lin;Wenzhi Zhou;Min Chen; Appeared in: IEEE Transactions on Energy Conversion Publication date: Sep 2017, volume: 32, issue:3, pages: 857 - 865 Publisher: IEEE
» A Joint Optimization Approach for the Synthesis of Large 4-D Heterogeneous Antenna Arrays
 Abstract:Due to the inherent nonlinearity in the synthesis of large four dimensional (4-D) heterogeneous arrays, conventional pattern synthesis techniques are no longer suitable. In this paper, an effective joint optimization approach based on the combination of convex programming (CP) and differential evolution (DE) algorithm is proposed. By designing suitable time sequences of a 4-D heterogeneous array with uniform static amplitude excitations, the original synthesis problem is simplified into two independent small problems, which can be easily solved in two steps, respectively. In the first step, the approach takes definite advantages from the convexity of the problem with respect to the static phase excitations and the switch-on duration times. These optimization variables become known and are fixed in the second step. Then, the DE algorithm is used to optimize the switch-on time instants. Owing to the efficiency of the CP, only 2/3 of the optimization variables need be solved in the first step, while even fewer number of optimization variables are solved in the second step. Consequently, the joint optimization of CP and DE algorithm significantly improves the overall synthesis efficiency. Two numerical examples are presented to demonstrate the effectiveness of the proposed approach. Autors: Feng Yang;Shiwen Yang;Yikai Chen;Shiwei Qu; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4585 - 4594 Publisher: IEEE
» A language for the internet of underwater things [News]
 Abstract:Aquatic robots are busier than ever. They have seabeds to mine, cable pathways to plough, and marine data to gather. But they and their aquatic brethren-including submarines and scuba divers-still struggle to communicate. For decades, global standards defining Wi-Fi and cellular networks have allowed people to exchange data over the air. But those technologies are worthless below the waves, and no such standards have existed for underwater communications. Aquatic systems have instead used a mishmash of acoustic and optical signals to send and receive messages. Autors: Amy Nordrum; Appeared in: IEEE Spectrum Publication date: Sep 2017, volume: 54, issue:9, pages: 9 - 10 Publisher: IEEE
» A Linearization Technique for Differential OTAs
 Abstract:This brief presents an operational transconductance amplifier (OTA) linearization technique that is applied to a low-noise amplifier (LNA) and an OTA-C filter. Simulations show the effectiveness of the proposed technique on the LNA, whose noise and gain performance remain unaffected while the linearity is significantly improved. Measurements of the 80-MHz fourth order Butterworth OTA-C filter are also presented. It is implemented using six OTAs instead of eight, thus reducing the power consumption and area. The filter is implemented in 65-nm low-power CMOS, with a core area of 0.05 mm and consumes 12.6 mA from 1.2 V supply. The measured in-band noise voltage is below 42 nV/, and the measured third order intercept point improvement using OTA linearization is up to 17 dB in-band and about 3 dB out-of-band. Supply and temperature variation measurements on three samples show that the linearization is effective without a need for bias adjustment. Autors: Mohammed Abdulaziz;Waqas Ahmad;Markus Törmänen;Henrik Sjöland; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1002 - 1006 Publisher: IEEE
» A Low-Cost Approach to the Skin Effect Compensation in Cylindrical Shunts
 Abstract:In this paper the development of a new design solution for high-current shunt resistors is presented, which allows achieving very good accuracy while requiring a simple and low-cost manufacturing process. It is based on a solid cylinder having the voltage measurement circuit which runs through two holes drilled in the cylinder itself. Starting from the well-known expression of the current density in a cylindrical conductor, the frequency response of the shunt is obtained in closed form as a function of the geometric parameters. In turn, the positions of the voltage measurement terminals are chosen by optimizing the frequency response function over a specified range. A shunt prototype has been manufactured and its measurement performance has been evaluated. The experimental results confirm the validity of the approach and highlight the significant improvement with respect to the single-hole cylindrical shunt which has been recently proposed by the authors. The obtained measurement accuracy is noticeable when compared with the ease of manufacturing. Autors: Marco Faifer;Roberto Ferrero;Christian Laurano;Roberto Ottoboni;Sergio Toscani;Michele Zanoni; Appeared in: IEEE Transactions on Instrumentation and Measurement Publication date: Sep 2017, volume: 66, issue:9, pages: 2266 - 2273 Publisher: IEEE
» A Low-Noise Charge Amplifier for the ELENA Trajectory, Orbit, and Intensity Measurement System
 Abstract:A low-noise head amplifier has been developed for the extra low energy antiproton ring beam trajectory, orbit, and intensity measurement system at CERN. This system is based on 24 double-electrode electrostatic beam position monitors installed around the ring. A head amplifier is placed close to each beam position monitor to amplify the electrode signals and generate a difference and a sum signal. These signals are sent to the digital acquisition system, about 50 m away from the ring, where they are digitized and further processed. The beam position can be measured by dividing the difference signal by the sum signal while the sum signal gives information relative to the beam intensity. The head amplifier consists of two discrete charge preamplifiers with junction field effect transistor (JFET) inputs, a sum and a difference stage, and two cable drivers. Special attention has been paid to the amplifier printed circuit board design to minimize the parasitic capacitances and inductances at the charge amplifier stages to meet the gain and noise requirements. The measurements carried out on the head amplifier showed a gain of 40.5 and 46.5 dB for the sum and difference outputs with a bandwidth from 200 Hz to 75 MHz and an input voltage noise density lower than . Twenty head amplifiers have been already installed in the ring and they have been used to detect the first beam signals during the first commissioning stage in November 2016. Autors: Ricardo Marco-Hernández;Marco Baú;Marco Ferrari;Vittorio Ferrari;Flemming Pedersen;Lars Søby; Appeared in: IEEE Transactions on Nuclear Science Publication date: Sep 2017, volume: 64, issue:9, pages: 2465 - 2473 Publisher: IEEE
» A Low-Power NB-IoT Transceiver With Digital-Polar Transmitter in 180-nm CMOS
 Abstract:A fully integrated 750~960 MHz wireless transceiver (TRX) is presented for single-tone NB-IoT applications. Effective design methodologies and techniques, from the system level to circuit level, are proposed to address various design challenges while achieving low-power consumption. The TRX consists of a low-IF receiver with 180-kHz signal bandwidth, a digital polar transmitter with 3.75-kHz signal bandwidth, and a fractional-N frequency synthesizer. Passive current mixer is employed in the receiver to improve the linearity and avoid the sensitivity degradation due to 1/ noise. Automatic I/Q imbalance calibration is integrated to improve image rejection ratio (IRR) with the aid of external FPGA. The transmitter is implemented in the digital polar architecture to improve the narrow-band spectrum purity, integrated with an inverse Class-D digital power amplifier (DPA) to achieve high output power and efficiency. A Class-C voltage-controlled oscillator with automatic frequency control assisted the dynamic gate biasing technique is used in the fractional-N PLL frequency synthesizer. Two prototypes are implemented in 180-nm CMOS. By optimizing analog baseband configuration in the receiver and utilizing the revised thermometer-coding and binary-coding-based array placement in the DPA, the receiver achieves 4.0-dB noise figure, 48-dB IRR, and 60-dB PGA dynamic range, and the DPA outputs 23.2dBm maximum saturation power with 44.5% PAE. Furthermore, the transmitter system verifications demonstrate 3.87% error-vector magnitude (EVM) for 891 MHz /4-DQPSK signals at 18.87-dBm output power with −40-dBc out-of-band rejection. The transmitter achieves a dynamic range from −35 to 20 dBm when the demodulation EVM threshold of the sys- em is set to 10%. Autors: Zheng Song;Xiliang Liu;Xiaokun Zhao;Qiongbing Liu;Zongming Jin;Baoyong Chi; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2569 - 2581 Publisher: IEEE
» A Low-Power SiGe BiCMOS 190-GHz Transceiver Chipset With Demonstrated Data Rates up to 50 Gbit/s Using On-Chip Antennas
 Abstract:This paper presents a 190-GHz direct conversion transceiver (TRX) chipset with on-chip antennas implemented in a 130-nm SiGe BiCMOS technology for short-distance high-data-rate wireless links. The transmitter (TX) consists of an active fundamental upconversion mixer, a local oscillator (LO) driver, and a passive balun for differential to single-ended conversion of the RF signal. The receiver (RX) is composed of a low-noise amplifier, an active fundamental mixer, an LO driver, a variable-gain baseband (BB) amplifier, and a totem-pole output stage. The wireless communication between TX and RX is enabled by on-chip monopole antennas, which are fabricated using standard wire-bonding tools. Measurements of the TRX chipset equipped with these antennas show a 6-dB BB link bandwidth of 20 GHz, corresponding to 40 GHz of the RF link bandwidth. In a data transmission test setup based on a BPSK modulation, data rates of up to 40 Gbit/s over 20 mm and up to 50 Gbit/s over 6 mm are demonstrated. Consuming only 122 mW in the RX and 32 mW in the TX, this leads to a very low required energy per transferred bit of 3.9 and 3.1 pJ for the 40- and 50-Gbit/s link, respectively. Autors: David Fritsche;Paul Stärke;Corrado Carta;Frank Ellinger; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3312 - 3323 Publisher: IEEE
» A Lyapunov Function for Switching Command of a DC–DC Power Converter With an LC Input Filter
 Abstract:This paper describes a method to control a dc–dc switching power converter with an LC input filter working under continuous conduction mode. It is known that the interaction between the low-pass filter and the tightly controlled switching converter occurs, and it might lead to an instability operation. The idea of this method relies on the Lyapunov stability criterion. The switching command of this control is defined by the manner of pre-evaluating the stability of the controlled system. All state variables are controlled in the same time. Therefore, the responses of this controlled system are fast while guaranteeing a stable operation. The proposed control is applied to a boost converter to demonstrate the implementation and its performance. The simulation and experimental results validate the proposed control approach. Autors: Roghayeh Gavagsaz-Ghoachani;Matheepot Phattanasak;Jean-Philippe Martin;Serge Pierfederici;Babak Nahid-Mobarakeh;Pierre Riedinger; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 5041 - 5050 Publisher: IEEE
» A Mathematical Model of Non-Diffusion-Based Mobile Molecular Communication Networks
 Abstract:This letter presents a mathematical model of molecular communication networks where mobile bio-nanomachines coordinate their motion by using non-diffusive surface-bound molecules for detecting and localizing spatially distributed targets in the environment. The mathematical model assumes that bio-nanomachines release two types of molecule: repellents to distribute bio-nanomachines in search of targets and attractants to attract distributed bio- nanomachines toward target locations. The two types of molecule assumed in this letter are non-diffusive, meaning that molecules bind to a surface in the environment, creating concentration gradients on the surface in order to distribute bio-nanomachines according to the target distribution. In this letter, we first develop dimensionless equations for the non-diffusion-based mobile molecular communication networks. We then perform mathematical analysis to show that, at steady-state, bio- nanomachines distribute according to a given target distribution. Finally, we demonstrate through numerical experiments that the bio-nanomachine distribution converges to the steady-state solution. Autors: Satoru Iwasaki;Jian Yang;Tadashi Nakano; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 1969 - 1972 Publisher: IEEE
» A Message from the Editorial Team and an Introduction to the July-September 2017 Issue
 Abstract: Autors: Peter Brusilovsky;Mike Sharples; Appeared in: IEEE Transactions on Learning Technologies Publication date: Sep 2017, volume: 10, issue:3, pages: 260 - 261 Publisher: IEEE
» A Method for Consistent Estimation of Multiple Land Surface Parameters From MODIS Top-of-Atmosphere Time Series Data
 Abstract:Most methods for generating global land surface products from satellite data are parameter specific and do not use multiple temporal observations, which often results in spatial and temporal discontinuity and physical inconsistency among different products. This paper proposes a data assimilation (DA) scheme to simultaneously estimate five land surface parameters from Moderate Resolution Imaging Spectroradiometer (MODIS) top-of-atmosphere (TOA) time series reflectance data under clear and cloudy conditions. A coupled land surface–atmosphere radiative transfer model is developed to simulate TOA reflectance, and an ensemble Kalman filter technique is used to retrieve the most influential surface parameters of the coupled model, such as leaf area index, by combining predictions from dynamic models and the MODIS TOA reflectance data whether under clear or cloudy conditions. Then, the retrieved surface parameters are input to the coupled model to calculate four other parameters: 1) land surface reflectance; 2) incident photosynthetically active radiation (PAR); 3) land surface albedo; and 4) the fraction of absorbed PAR (FAPAR). The estimated parameters are compared with those of the corresponding MODIS, the Global LAnd Surface Satellite, and the Geoland2/BioPar version 1 (GEOV1) products. Validation of the estimated parameters against ground measurements from several sites with different vegetation types demonstrates that this method can estimate temporally complete land surface parameter profiles from MODIS TOA time series reflectance data, with accuracy comparable to that of existing satellite products over the selected sites. The retrieved leaf area index profiles are smoother than the existing satellite products, and unlike the MOD09GA product, the retrieved surface reflectance values do not have the high peak values influenced by clouds. The use of the coupled land surface–atmosphere model a- d the DA technique ensures physical connections between the land surface parameters and makes it possible to calculate radiation-related parameters for clear and cloudy atmospheric conditions, which is an improvement for FAPAR retrieval compared with the MODIS and GEOV1 products. The retrieved FAPAR and PAR values can reveal the significant differences in them under clear and cloudy atmospheric conditions. Autors: Hanyu Shi;Zhiqiang Xiao;Shunlin Liang;Han Ma; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 5158 - 5173 Publisher: IEEE
» A Millimeter-Wave Indoor Backscattering Channel Model for Environment Mapping
 Abstract:In this communication, we introduce a channel model for personal radar applications where a millimeter-wave (mm-wave) massive array is required to scan the environment and to reconstruct a map of it. The analysis is based on measurement campaigns, in a corridor and in an office room, performed using mm-wave massive arrays. In such a context, we aim at characterizing the channel from both a temporal and an angular perspective by exploiting a 2D CLEAN-like technique to extrapolate the multipath components and a K-means algorithm for clustering, where centroids statistics depend on the environment contour. The obtained channel model can be exploited for mapping algorithms based on backscattered radar measurements. Autors: Anna Guerra;Francesco Guidi;Davide Dardari;Antonio Clemente;Raffaele D’Errico; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4935 - 4940 Publisher: IEEE
» A Millimeter-Wave Klystron Upconverter With a Higher Order Mode Output Cavity
 Abstract:Manufacturing of klystrons in the millimeter-wave frequency range is challenging due to the small size of the cavities and the ratio of the maximum gap voltage to the beam energy. The small dimensions also make difficult to produce devices with the output power required by a number of applications at millimeter wave, such as communications and spectroscopy. Operating with a higher order mode can be a potential solution, as a larger transverse size structure can be used. Unfortunately, high-order mode cavities have a lower impedance than in fundamental mode. In this paper is proposed a novel solution to overcome the reduced impedance by utilizing an upconverter, where all cavities except the output cavity are designed to work in high-order mode. To demonstrate the effectiveness of the approach, two klystron upconverters were designed. One has six cavities aiming to achieve a maximum output power of ~90 W at 105 GHz. The second klystron upconverter was a simpler three-cavity structure designed for quick prototype. Millimeter-wave measurements of the three-cavity klystron upconverter are presented. Autors: Graeme Burt;Liang Zhang;David A. Constable;Huabi Yin;Chris J. Lingwood;Wenlong He;Claudio Paoloni;Adrian W. Cross; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3857 - 3862 Publisher: IEEE
» A Model-Based Predictive Direct Power Control for Traction Line-Side Converter in High-Speed Railway
 Abstract:With the rapid development of China high-speed railway, the low frequency oscillation (LFO) of electrical quantities appears more often recently and leads to some severe problems of train operation. To improve the traction line-side converter control and suppress the phenomenon economically and effectively, a model-based predictive direct power control (MPDPC) approach is proposed in this paper. The approach adopts a discrete-time model of traction line-side converter in d–q reference frame to predict the future values of the input active and reactive power. The optimal switching state is selected by minimizing a cost function of power to evaluate the power errors at the next sampling time. Through the theoretical analysis and simulations, the performance of MPDPC is compared with traditional transient direct current control (TDCC) that is widely adopted in China Railway High-Speed 3 electric-multiple-unit. The real-time online simulations based on Real-Time Laboratory (RT-LAB) are also realized to further validate the results. Moreover, two vehicle-grid cascade simulation systems are constructed, and the LFO suppressing capability of MPDPC and TDCC is compared. Finally, the steady-state characteristic, dynamic characteristic, and LFO suppressing capability of MPDPC are demonstrated through the analysis of key performance indexes. Autors: Zhigang Liu;Chuan Xiang;Yaqi Wang;Yicheng Liao;Guinan Zhang; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4934 - 4943 Publisher: IEEE
» A Model-Based Strategy for Interturn Short-Circuit Fault Diagnosis in PMSM
 Abstract:A model-based method for interturn short-circuit fault detection and isolation in permanent magnet synchronous machines (PMSMs) is proposed in this paper. The fault detection is realized based on a residual current vector (RCV) generated by the difference between the measured stator currents and the stator currents estimated by a state observer. In order to avoid false alarms due to possible undesired perturbations, the sequence decomposition of the RCV is performed by employing different reference-frames. Thus, the proposed RCV allows the correct detection of interturn short-circuit faults and quantification of the fault severity in any faulty stator-phase winding. Moreover, since the back-EMF generated by the magnets is proportional to the rotor shaft speed, the electrical angular speed is estimated through the stator voltages measurement, without using a speed sensor. Simulation results from the three-phase PMSM dynamic model that allows considering the interturn short-circuit fault in any stator phase-windings are presented. The proposed method is validated using a three-phase PMSM prototype with modified stator windings. The robustness and the reliability of the proposal was tested for several interturn fault conditions under transient conditions including different disturbances. Autors: Manuel A. Mazzoletti;Guillermo R. Bossio;Cristian H. De Angelo;Diego R. Espinoza-Trejo; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7218 - 7228 Publisher: IEEE
» A Modified Plane Wave Model for Fast and Accurate Characterization of Layered Media
 Abstract:The accuracy and computational speed of ground penetrating radar (GPR) largely rely on the inverse model implemented. In most cases, both accuracy and processing speed cannot be achieved together because of the inherent limitation of modeling GPR signal in complex media. Full wave models (FWMs) are most promising approaches to characterize multilayered media. However, they are inefficient due to the requirement of significant time for integration over singularity. In this paper, a modified plane wave model (MPWM) is proposed to achieve accuracy and better computational speed. The model is derived based on the analytical solution of an FWM. It is versatile for finding response due to multilayered media. The rigorous analysis has shown the similarity between the proposed model and FWMs with cross-correlation value close to unity across a broad frequency spectrum and large ranges of media parameters. Model inversion is achieved by a novel layer stripping technique followed by a gradient-based method. Testing of layered media in laboratory environment demonstrates that the proposed MPWM has significant advantage over FWMs. Autors: Subrata Maiti;Sarat Kumar Patra;Amitabha Bhattacharya; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3492 - 3502 Publisher: IEEE
» A Modified T-Structured Three-Level Inverter Configuration Optimized With Respect to PWM Strategy Used for Common-Mode Voltage Elimination
 Abstract:This paper presents an optimized topology for a three-level inverter with complete elimination of common-mode voltage (CMV). The proposed multilevel inverter (MLI) configuration is realized by modifying a T-structure inverter. The proposed configuration is an optimized solution with respect to the pulse-width modulation strategy used for CMV elimination. The given three-level inverter structure uses only 16 power semiconductor switches, which is much lower than the existing configurations. A reduced number of power semiconductor devices results in a diminished number of driver circuits, less installation space, and low cost. Further, due to the complete elimination of CMV, the proposed MLI is free from issues such as electromagnetic interference and leakage current with a reduction in filter requirement. The presented topology is also compared with other existing topologies to prove its advantage. It is an optimized solution with respect to the dc bus voltage requirement and the total voltage rating of the devices or the components used in the system. Simulation and experimental results are presented to confirm the capability of the proposed MLI. Autors: Arpan Hota;Sachin Jain;Vivek Agarwal; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4779 - 4787 Publisher: IEEE
» A Modular Multilevel Generic Pulse-Waveform Generator for Pulsed Electric Field Applications
 Abstract:High-voltage (HV) pulses are used in pulsed electric field (PEF) applications to provide an effective electroporation process, a process in which harmful microorganisms are disinfected when subjected to a PEF. Depending on the PEF application, different HV pulse specifications are required such as the pulse-waveform shape, the voltage magnitude, the pulse duration, and the pulse repetition rate. In this paper, a generic pulse-waveform generator (GPG) is proposed, and the GPG topology is based on half-bridge modular multilevel converter (HB-MMC) cells. The GPG topology is formed of four identical arms of series-connected HB-MMC cells forming an H-bridge. Unlike the conventional HB-MMC-based converters in HVdc transmission, the GPG load power flow is not continuous which leads to smaller size cell capacitors utilization; hence, smaller footprint of the GPG is achieved. The GPG topology flexibility allows the controller software to generate a basic multilevel waveform which can be manipulated to generate the commonly used PEF pulse waveforms. Therefore, the proposed topology offers modularity, redundancy, and scalability. The viability of the proposed GPG converter is validated by MATLAB/Simulink simulation and experimentation. Autors: Mohamed A. Elgenedy;Ahmed Darwish;Shehab Ahmed;Barry W. Williams; Appeared in: IEEE Transactions on Plasma Science Publication date: Sep 2017, volume: 45, issue:9, pages: 2527 - 2535 Publisher: IEEE
» A MPTCP-Based Network Architecture for Intelligent Train Control and Traffic Management Operations
 Abstract:This paper investigates a novel communication system architecture for traffic management and data control in railway scenarios. The proposed solution should be integrated in the existing European Railway Traffic Management System/European Train Control System, the most advanced and successful standard even outside the European countries. Our system integrates public land mobile networks that usually offer best-effort packet services, with a quality-of-service (QoS) guaranteed satellite network. It represents a cost-effective substitution for 4G and 5G networks, aiming to replace current well-known GSM-R standard. The coexistence of heterogeneous networks is guaranteed by the multi-path transmission control protocol (TCP) protocol that addresses specific “add and drop” subflow policies and priority handling logics, in order to realize efficient seamless handovers. Providing priority to TCP subflows corresponds to select QoS-guaranteed, and the best effort networks able to fulfill railway requirements. The logic of adding and dropping subflows exploits both a real-time check of the current status of the serving network and “a priori” network performance information. Experimental results have been carried out in both city and harsh environments, where the main performance metrics (i.e., average delay, jitter, and bit rate) have been assessed. Autors: Yiwei Liu;Alessandro Neri;Agostino Ruggeri;Anna Maria Vegni; Appeared in: IEEE Transactions on Intelligent Transportation Systems Publication date: Sep 2017, volume: 18, issue:9, pages: 2290 - 2302 Publisher: IEEE
» A Multi-Agent Advanced Traveler Information System for Optimal Trip Planning in a Co-Modal Framework
 Abstract:We present an advanced traveler information system (ATIS) for public and private transportation, including vehicle sharing and pooling services. The ATIS uses an agent-based architecture and multi-objective optimization to answer trip planning requests from multiple users in a co-modal setting, considering vehicle preferences and conflicting criteria. At each set of users’ requests, the transportation network is represented by a co-modal graph that allows decomposing the trip planning problem into smaller tasks: the shortest routes between the network nodes are determined and then combined to obtain possible itineraries. Using multi-objective optimization, the set of user-vehicle-route combinations according to the users’ preferences is determined, ranking all possible route agents’ coalitions. The ATIS is tested for the real case study of the Lille metropolitan area (Nord Pas de Calais, France). Autors: Mariagrazia Dotoli;Hayfa Zgaya;Carmine Russo;Slim Hammadi; Appeared in: IEEE Transactions on Intelligent Transportation Systems Publication date: Sep 2017, volume: 18, issue:9, pages: 2397 - 2412 Publisher: IEEE
» A Multi-Objective Optimization Approach for Question Routing in Community Question Answering Services
» A Multi-Stage Solution for NFV-Enabled Multicast Over the Hybrid Infrastructure
 Abstract:The network function virtualization-enabled multicast problem includes constructing traffic forwarding topology, deploying required functions and steering traffic through them. Currently, jointly taking them into consideration is still an open problem and we propose a multi-stage solution to solve it. Specifically, we separate the multicast traffic forwarding and function delivery. The traffic forwarding topology is constructed with minimum spanning tree and the function delivery is implemented with the backtracking strategy. Simulation results show that the proposed solution achieves good performance. Autors: Bo Yi;Xingwei Wang;Min Huang;Anwei Dong; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 2061 - 2064 Publisher: IEEE
» A Multivariate Approach for Patient-Specific EEG Seizure Detection Using Empirical Wavelet Transform
 Abstract:Objective: This paper investigates the multivariate oscillatory nature of electroencephalogram (EEG) signals in adaptive frequency scales for epileptic seizure detection. Methods: The empirical wavelet transform (EWT) has been explored for the multivariate signals in order to determine the joint instantaneous amplitudes and frequencies in signal adaptive frequency scales. The proposed multivariate extension of EWT has been studied on multivariate multicomponent synthetic signal, as well as on multivariate EEG signals of Children's Hospital Boston-Massachusetts Institute of Technology (CHB-MIT) scalp EEG database. In a moving-window-based analysis, 2-s-duration multivariate EEG signal epochs containing five automatically selected channels have been decomposed and three features have been extracted from each 1-s part of the 2-s-duration joint instantaneous amplitudes of multivariate EEG signals. The extracted features from each oscillatory level have been processed using a proposed feature processing step and joint features have been computed in order to achieve better discrimination of seizure and seizure-free EEG signal epochs. Results: The proposed detection method has been evaluated over 177 h of EEG records using six classifiers. We have achieved average sensitivity, specificity, and accuracy values as 97.91%, 99.57%, and 99.41%, respectively, using tenfold cross-validation method, which are higher than the compared state of art methods studied on this database. Conclusion: Efficient detection of epileptic seizure is achieved when seizure events appear for long duration in hours long EEG recordings. Significance: The proposed method develops time–frequency plane for multivariate signals and builds patient-specific models for EEG seizure detection. Autors: Abhijit Bhattacharyya;Ram Bilas Pachori; Appeared in: IEEE Transactions on Biomedical Engineering Publication date: Sep 2017, volume: 64, issue:9, pages: 2003 - 2015 Publisher: IEEE
» A Nanosecond-Transient Fine-Grained Digital LDO With Multi-Step Switching Scheme and Asynchronous Adaptive Pipeline Control
 Abstract:This paper introduces a multi-step switching scheme for a digital low dropout regulator (DLDO) that emerges as a new way of achieving nanosecond-transient and fine-grained on-chip voltage regulation. The multi-step switching scheme takes advantage of the adaptive pipeline control and asynchronous clocking for area- and power-efficient digital controller utilization. It speeds up the transient response by varying the pass transistor sizing in two available lengths of coarse steps as per the perturbation, while maintaining a small output voltage ripple by toggling in a finer step at steady operation. A prototype proving the proposed concept, i.e., a 0.6–1.0-V input, 50–200-mV dropout, and 500-mA maximum loading DLDO with an on-chip 1.5-nF output capacitor, is fabricated in a 65-nm CMOS process to verify the effectiveness of this scheme. By employing the multi-step switching scheme and adaptive control, the DLDO achieved a fast transient response to nanoseconds loading current change, and a 100 mV per 10-ns reference voltage switching, as well as a resolution of 768 levels (~9.5 bits) with a 5-mV output ripple. The quiescent current consumed by this DLDO at steady operation is down to . Autors: Fan Yang;Philip K. T. Mok; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2463 - 2474 Publisher: IEEE
» A New Buck–Boost Converter With Low-Voltage Stress and Reduced Conducting Components
 Abstract:This paper presents a new buck–boost converter. Unlike the single-switch buck–boost converter, the proposed converter has low-voltage stresses on semiconductors. Moreover, although both the conventional two-switch buck–boost (TSBB) and the proposed converters have the same number of passive and active components, and the proposed converter can reduce the conduction loss as a result of having fewer conducting components. Therefore, the proposed converter obtained a higher efficiency than the TSBB converter. A 48-V output voltage and 150-W output power prototype was fabricated to verify the effectiveness of the proposed converter. Autors: Hyo-Soo Son;Jae-Kuk Kim;Jae-Bum Lee;Sang-Su Moon;Ji-Hoon Park;Seok-Hyun Lee; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7030 - 7038 Publisher: IEEE
» A New Electromagnetic Launcher by Sextupole Rails: Electromagnetic Propulsion and Shielding Numerical Validation
 Abstract:A novel sextupole rails electromagnetic launcher has been designed and validated with numerical simulations of electromagnetic propulsion and shielding. The sextupole rails and club-shaped projectile are proposed as that the club-shaped projectile carrying the sextupole toroidal currents is surrounded by the sextupole toroidal field created from the sextupole rails. The interaction between the toroidal magnetic field and the orthogonal toroidal currents results in the generation of axial acceleration force. The sextupole rails electromagnetic launcher can solve the problems of magnetic shielding without shielding coils or materials. The theoretical assessment of the propulsion force and magnetic shielding is performed by corresponding numerical validation based on finite-element simulations. The numerical simulation results demonstrate that the sextupole rails electromagnetic launcher represents high thrust/current ratios and productive magnetic shielding effect. Autors: Xinpeng Xue;Tao Shu;Zhiyong Yang;Gang Feng; Appeared in: IEEE Transactions on Plasma Science Publication date: Sep 2017, volume: 45, issue:9, pages: 2541 - 2545 Publisher: IEEE
» A New Framework of Filter Bank Multi-Carrier: Getting Rid of Subband Orthogonality
 Abstract:Filter bank multi-carrier (FBMC) entitles many advantages over orthogonal frequency division multiplexing (OFDM) and is considered to be a more competitive waveform in the future generation cellular communications. In current FBMC, the prototype filter is deliberately designed to meet the perfect reconstruction (PR) constraint to establish subband orthogonality in real domain, which may not be optimal from communication perspective. In this paper, we challenge the necessity of PR constraint by proposing a new FBMC framework, which directly accepts non-orthogonal transmission. The resulting imperfect reconstruction FBMC (iPR-FBMC) has several advantages over its PR FBMC counterpart: 1) the constraint on the prototype filter is relaxed; 2) more importantly, the prototype filter can now be optimized with new goal of improving the detection performance rather than having to meet the PR condition; and 3) it allows for more flexible subband management in multi-user scenario. We will show how those advantages can be exploited. Simulations show that with moderate increase in computational complexity, the proposed iPR-FBMC with optimized prototype filter has superior bit error rate (BER) performance to existing FBMC with PR constraint and even outperforms OFDM, especially in highly frequency selective channels. The findings may shed light into potential research on non-orthogonal FBMC without PR constraint. Autors: Jian Dang;Zaichen Zhang;Liang Wu;Yongpeng Wu; Appeared in: IEEE Transactions on Communications Publication date: Sep 2017, volume: 65, issue:9, pages: 3922 - 3932 Publisher: IEEE
» A New Harmonic Reduced Three-Phase Thyristor-Controlled Reactor for Static VAr Compensators
 Abstract:A new thyristor-controlled reactor scheme is presented in this paper, in which the total bank is split into one Δ- and one Y-connected reactor bank with the addition of a low-rating zig-zag autotransformer, instead of the conventional scheme using a Δ-connected reactor bank with a harmonic current filter. This arrangement prevents the triplen harmonics generated by the Y bank from entering into the supply system and at the same time, the combination results in cancellation of some major characteristic harmonics from the source current. Thus, without using any additional filters or phase-shifting two-winding transformer, this scheme facilitates reactive power control over a wide range and also meets the requisite harmonics standards. The scheme is simple and provides a cost-effective solution to the VAr compensation problem. Simulation and experimental results are provided to validate the proposed concept. Autors: Susovan Mukhopadhyay;Dipten Maiti;Ambarnath Banerji;Sujit K. Biswas;Nirmal K. Deb; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 6898 - 6907 Publisher: IEEE
» A New Kind of Article for Reproducible Research in Intelligent Robotics [From the Field]
 Abstract: Autors: Fabio Bonsignorio; Appeared in: IEEE Robotics & Automation Magazine Publication date: Sep 2017, volume: 24, issue:3, pages: 178 - 182 Publisher: IEEE
» A New Model for Resilient Distribution Systems by Microgrids Formation
 Abstract:Forming multiple micorgrids with distributed generators offers a resilient solution to restore critical loads from natural disasters in distribution systems. However, more dummy binary and continuous variables are needed with the increase of the number of microgrids, which will therefore increase the complexity of this model. To address this issue, this letter presents a new model to reformulate the micorgrid formulation problem in resilient distribution networks. Compared with the traditional model, the number of both binary and continuous variables is greatly reduced, such that the computational performance is significantly improved. Numerical results on IEEE test systems verify the effectiveness of the proposed model. Autors: Tao Ding;Yanling Lin;Gengfeng Li;Zhaohong Bie; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 4145 - 4147 Publisher: IEEE
» A New Paradigm for Spectrum Sharing Between Cellular Wireless Communications and Radio Astronomy Systems
» A New State-of-Charge Control Derivation Method for Hybrid Battery Type Integration
 Abstract:The hybrid of ex-transportation and conventional new battery system integration has started gaining interests within energy storage systems as number of electric vehicle on-road increases. Each module within such a system may consist of batteries with different charging/discharging rates, characteristics and also different nominal voltage levels. Control of these hybrid batteries within the same system is more challenging compared to conventional battery management systems, which mainly deal with the homogeneous battery system. One of the key issues is how to control the state-of-charge trajectory of the hybrid modules to maximize the investment on the new hybrid battery system. To cater this problem, this paper brings a new rigorous derivation method of state-of-charge control based on converter sample time. The proposed method generates desired current reference in each time step to distribute the power among hybrid modules such that their discharging or charging trajectories finish at the same time. This technique makes sure that the energy delivered/absorbed from each cell in a uniform manner maximizing the overall lifespan. Detailed derivation of the current sharing method and suitable module based adaptive bidirectional control architecture has also been presented. Modeling, analysis, and experimental validations are performed on a three-module-based grid-tie hybrid battery energy storage system prototype to validate analysis. Autors: Nilanjan Mukherjee;Dipankar De; Appeared in: IEEE Transactions on Energy Conversion Publication date: Sep 2017, volume: 32, issue:3, pages: 866 - 875 Publisher: IEEE
» A New Way for a New Generation [Editorial]
 Abstract: Autors: Cristian Quintero; Appeared in: IEEE Potentials Publication date: Sep 2017, volume: 36, issue:5, pages: 3 - 3 Publisher: IEEE
» A Novel Adaptive Fuzzy Local Information $C$ -Means Clustering Algorithm for Remotely Sensed Imagery Classification
 Abstract:This paper presents a novel adaptive fuzzy local information c-means (ADFLICM) clustering approach for remotely sensed imagery classification by incorporating the local spatial and gray level information constraints. The ADFLICM approach can enhance the conventional fuzzy c-means algorithm by producing homogeneous segmentation and reducing the edge blurring artifact simultaneously. The major contribution of ADFLICM is use of the new fuzzy local similarity measure based on pixel spatial attraction model, which adaptively determines the weighting factors for neighboring pixel effects without any experimentally set parameters. The weighting factor for each neighborhood is fully adaptive to the image content, and the balance between insensitiveness to noise and reduction of edge blurring artifact to preserve image details is automatically achieved by using the new fuzzy local similarity measure. Four different types of images were used in the experiments to examine the performance of ADFLICM. The experimental results indicate that ADFLICM produces greater accuracy than the other four methods and hence provides an effective clustering algorithm for classification of remotely sensed imagery. Autors: Hua Zhang;Qunming Wang;Wenzhong Shi;Ming Hao; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 5057 - 5068 Publisher: IEEE
» A Novel Approach to Array Manifold Calibration Using Single-Direction Information for Accurate Direction-of-Arrival Estimation
 Abstract:A method of array manifold calibration using one steering vector measured in a single direction is proposed. The phase information of the measured steering vector is used to derive a novel calibration matrix that is proposed to compensate for the relative phase distortion (RPD) at each antenna port. We also present a metric function defined as a standard deviation of the RPD to determine the optimum calibration angle, which provides intuition for the cause of the accuracy degradation in the direction-of-arrival estimation. To verify the feasibility, a seven-element circular array with identical microstrip patch antennas is fabricated for calibrating its array manifold using a single steering vector measured in a full anechoic chamber. The calibrated array manifold is then used to estimate the direction of arrival, and its accuracy is compared to the calibrated result obtained from the traditional least-squares method. The results demonstrate that the estimation error can be improved by 54.9° compared to the traditional least-squares method, when the number of measured steering vectors is extremely limited. Autors: Gangil Byun;Hosung Choo; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4952 - 4957 Publisher: IEEE
» A Novel Autonomous Initial Alignment Method for Strapdown Inertial Navigation System
 Abstract:In-motion alignment of strapdown inertial navigation systems (SINS) without any geodetic-frame observations is one of the toughest challenges for autonomous vehicles. Considering the characteristics of SINS, this paper presents a dual-model-based in-motion alignment method for the odometer-aided SINS. Two inertial navigation calculation loops are established for an inertial measurement unit (IMU), one of which executes the in-motion gyrocompass horizontal alignment algorithm to decompose the body velocity measured by odometer to navigation frame and attenuate the disturbance. And the other is the attitude determination-based alignment loop, where the vector observation-based SINS alignment is executed. The contributions of the work presented here are twofold. First, the dual-model initial alignment (DMIA) algorithm for SINS is proposed, which introduces the idea of constructing multiple calculation loops for an IMU to maximize the advantages of SINS. Second, depending on the body-frame speed-aided attitude determination and navigation-frame speed-aided attitude determination, the body-frame velocity observation with disturbance is accurately decomposed to navigation frame with the noise attenuated by gyrocompass horizontal alignment. The experimental results show that the proposed DMIA algorithm can achieve a rapid and accurate in-motion alignment. Autors: Jiangning Xu;Hongyang He;Fangjun Qin;Lubin Chang; Appeared in: IEEE Transactions on Instrumentation and Measurement Publication date: Sep 2017, volume: 66, issue:9, pages: 2274 - 2282 Publisher: IEEE
» A Novel Bayesian Spatial–Temporal Random Field Model Applied to Cloud Detection From Remotely Sensed Imagery
 Abstract:With the fast advancement of remote sensing platforms and sensors, remotely sensed imagery (RSI) is increasingly being characterized by both high spatial resolution and high temporal resolution. How to efficiently use the rich spatial and temporal information in RSI for highly accurate object detection and classification is an important research question. Nevertheless, there is still a lack of a probabilistic framework that is capable of fully accounting for the spatial–temporal information in RSI for improved applications. In this paper, we present a Bayesian spatial–temporal random field model that constitutes a complete probabilistic framework for fully explaining the spatial–temporal correlation in RSI, leading to an enhanced object detection approach that is used for cloud detection from RSI. Under the Bayesian theorem, the posterior distribution of a label field is decomposed into the label prior, the data likelihood, the temporal label likelihood, and the temporal data likelihood. To address the difficulties in modeling the complex spatial–temporal correlation effect in the temporal data likelihood, a stochastic sampling approach is presented. Based on the maximum a posteriori approach, the posterior distribution is seamlessly integrated into the graph-cut optimization framework, and, therefore, the model optimization can be efficiently solved. The proposed algorithm is tested for cloud detection on both simulated and real RSIs and the results demonstrate that the proposed algorithm can effectively exploit the spatial–temporal information for achieving higher detection accuracy. Autors: Linlin Xu;Alexander Wong;David A. Clausi; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 4913 - 4924 Publisher: IEEE
» A Novel Cross-Feedback Notch Filter for Synchronous Vibration Suppression of an MSFW With Significant Gyroscopic Effects
 Abstract:To effectively suppress the synchronous vibration torques for a magnetically suspended rotor (MSR) with significant gyroscopic effects and serious coupling dynamics, a novel cross-feedback notch filter is proposed in this paper. First, the coupled multi-input-multi-output active magnetic bearing rotor system is converted into an equivalent complex single-input single-output (SISO) system. The equivalent transformation aims at easing the controller design and extending the classical stability criterion to the complex coefficient frequency domain. Then, the principle and implementation of the proposed scheme used for synchronous vibration suppression over an entire rotational speed range is analyzed in details. The performance compared with the conventional decentralized notch filter is investigated. Moreover, the closed-loop stability, which based on the equivalent complex SISO system and complex-coefficient stability criterion is given. Experimental results on a magnetically suspended flywheel demonstrate the significant effect of the proposed method on both synchronous vibration suppression and stability preservation. Autors: Cong Peng;Jinji Sun;Cunxiao Miao;Jiancheng Fang; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7181 - 7190 Publisher: IEEE
» A Novel DC-Power Control Method for Cascaded H-Bridge Multilevel Inverter
 Abstract:The cascaded H-bridge converter has been widely used in industry. The ability of dealing with unequal power generation among dc links is necessarily required in many applications, such as large-scale photovoltaic power plants and electric vehicles. In this paper, a novel dc-power control method (PCM) is proposed to keep the ac-current balance and maintain power generation ratios of each dc source at their expected values. A simplified modulation strategy is introduced to implement the proposed method, in which the duration times are modified directly by the correction value derived from the PCM method. To calculate and adjust the power generation ratios, a method based on first-in first-out (FIFO) data queue is utilized. The limitation and ranges of power generation ratio are analyzed in detail. DC power per phase can be controlled accurately by the proposed method in variable-frequency condition, even under larger power generation ratios. Results obtained from simulations and experiments are presented to verify the feasibilities and superiorities of the proposed method. Autors: Zongbin Ye;Linlin Jiang;Zhiguo Zhang;Dongsheng Yu;Zhichuan Wang;Xianming Deng;Tyrone Fernando; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 6874 - 6884 Publisher: IEEE
» A Novel Elastic Force-Field to Influence Mediolateral Foot Placement During Walking
 Abstract:Bipedal gait can be stabilized through mechanically-appropriate mediolateral foot placement, although this strategy is disrupted in a subset of neurologically injured individuals with balance deficits. The goal of the present work was to develop a device to influence mediolateral foot placement during treadmill walking. We created a novel force-field using a combination of passive elasticity and active control; wires in series with extension springs run parallel to the treadmill belts and can be rapidly repositioned to exert mediolateral forces on the legs of users. This mechanical structure creates a channel-like force landscape that resists displacements of each leg away from its prescribed mediolateral position, producing near-linear effective mediolateral stiffness. The depth of these force-field channels can be predictably controlled by manipulating extension spring initial tension. In human testing, we found that the force-field can effectively “get-out-of-the-way” when desired, closely following the mediolateral leg trajectory with a delay of approximately 110 ms. The force-field can also encourage users to adjust their mediolateral foot placement in order to walk with either narrower or wider steps, without interfering with forward gait progression. Future work will test whether this novel device can help retrain a stable gait pattern in clinical populations. Autors: Elizabeth T. Nyberg;Jordan Broadway;Christian Finetto;Jesse C. Dean; Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering Publication date: Sep 2017, volume: 25, issue:9, pages: 1481 - 1488 Publisher: IEEE
» A Novel GNSS Technique for Predicting Boreal Forest Attributes at Low Cost
 Abstract:One of the biggest challenges in forestry research is the effective and accurate measuring and monitoring of forest variables, as the exploitation potential of forest inventory products largely depends on the accuracy of estimates and on the cost of data collection. This paper presented a novel computational method of low-cost forest inventory using global navigation satellite system (GNSS) signals in a crowdsourcing approach. Statistical features of GNSS signals were extracted from widely available GNSS devices and were used for predicting forest attributes, including tree height, diameter at breast height, basal area, stem volume, and above-ground biomass, in boreal forest conditions. The basic evidence of the predictions is the physical correlations between forest variables and the responses of GNSS signals penetrating through the forest. The random forest algorithm was applied to the predictions. GNSS-derived prediction accuracies were comparable with those of the most accurate 2-D remote sensing techniques, and the predictions can be improved further by integration with other publicly available data sources without additional cost. This type of crowdsourcing technique enables the collection of up-to-date forest data at low cost, and it significantly contributes to the development of new reference data collection techniques for forest inventory. Currently, field reference can account for half of the total costs of forest inventory. Autors: Jingbin Liu;Juha Hyyppä;Xiaowei Yu;Anttoni Jaakkola;Antero Kukko;Harri Kaartinen;Lingli Zhu;Xinlian Liang;Yunsheng Wang;Hannu Hyyppä; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 4855 - 4867 Publisher: IEEE
» A Novel Group Engagement Score for Virtual Learning Environments
 Abstract:STEM (Science, Technology, Engineering, and Math) education is currently receiving much attention from governments and educational institutions. Our work is based on active learning and video-based learning approaches to support STEM education. Here, we aimed to increase student's engagement through reflective processes that embrace video film-making, and subsequent on-line discussion and evaluation of those videos. We propose a group engagement score that takes into account both individual activity and similarity of participation, thus allowing corrective actions to be taken when unengaged students or groups are identified. We tested these ideas using our own social learning platform that combines the principal features of Social Networks with tools that facilitate collaborative learning design. This platform stimulates students’ learning by means of two main reflective processes: participatory production and peer-review. We evaluated this platform and the learning approach it supports in an Object Oriented Programming course and identified interesting differences between group engagement and video ratings. Our principal conclusion is that greater teacher and student awareness of the ongoing activities and group engagement are needed. Autors: Jorge Castellanos;Pablo A. Haya;Jaime Urquiza-Fuentes; Appeared in: IEEE Transactions on Learning Technologies Publication date: Sep 2017, volume: 10, issue:3, pages: 306 - 317 Publisher: IEEE
» A Novel Hardware-Efficient Cochlea Model Based on Asynchronous Cellular Automaton Dynamics: Theoretical Analysis and FPGA Implementation
 Abstract:A novel cochlear model based on the nonlinear dynamics of an asynchronous cellular automaton is presented. Theoretical bifurcation analyses show that the model can mimic a nonlinear vector field of a differential equation cochlea model. It is then shown that the presented model can reproduce biologically measured frequency tuning curves of multiple species. In addition, the presented model is implemented in a field programmable gate array and experiments validate reproductions of the biological tuning curves. It is also shown that the presented model can be implemented by fewer hardware resources as compared to the differential equation cochlea model. Autors: Kentaro Takeda;Hiroyuki Torikai; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1107 - 1111 Publisher: IEEE
» A Novel Hybrid Dual-PM Machine Excited by AC With DC Bias for Electric Vehicle Propulsion
 Abstract:This paper proposes a novel hybrid-excited dual-PM machine for electric vehicle propulsion. The key is to use an integrated stator winding to replace the armature winding and the field winding in the conventional hybrid-excited machine. The stator winding is excited by ac current with dc bias, in which the ac component is used to produce the rotating armature field, while the dc bias current is used for the flux regulation. Therefore, the function of the ac and dc windings can be incorporated and realized by using just one set of winding. The torque density and flux regulating capability can be improved, and the winding configuration is also simplified. In addition, dual-PM excitation structure combines the advantage of stator-PM doubly salient machine and rotor-PM magnetic-geared machine, which can further enhance the torque capability. The operating principle and control strategy of the proposed machine are discussed. The electromagnetic performances are studied using the time-stepping finite-element method. A machine prototype is manufactured and experimental tests are conducted to verify the effectiveness of the machine design. Autors: Qingsong Wang;Shuangxia Niu;Xiang Luo; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 6908 - 6919 Publisher: IEEE
» A Novel Hybrid Five-Level Voltage-Source Converter Based on T-Type Topology for High-Efficiency Applications
 Abstract:A novel hybrid five-level voltage-source converter for high-efficiency applications is investigated in this paper. Compared with traditional multilevel converters, this hybrid multilevel converter generates desired staircase voltage levels with a reduced number of power devices and isolated drivers at higher voltage levels. It has redundant switching state combinations in hybrid multilevel converter, which makes it easy to balance flying capacitor voltages and realize fault-tolerant operation. A voltage-balancing control strategy based on switching state redundancies is presented for the hybrid multilevel converter to generate desired levels and also keep voltage balance of flying capacitors at the same time. The performance of the hybrid multilevel converter under various operating conditions is investigated in MATLAB/Simulink. The effectiveness of the proposed hybrid multilevel converter is validated by experiment results. Autors: Shuai Xu;Jianzhong Zhang;Xing Hu;Yongjiang Jiang; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4730 - 4743 Publisher: IEEE
» A Novel Implant Electrode Design Safe in the RF Field of MRI Scanners
 Abstract:Patients with medical implants are often unable to receive magnetic resonance imaging (MRI) diagnostic treatment, because the conductive leads can concentrate the RF excitation field and generate dangerous heating of nervous tissue. We propose a simple, low-cost solution that minimizes RF heating through the addition of one or more mutually coupled filars to the lead without significant increase in lead diameter. Simulations and measurements at 128 MHz are presented to verify the effect in 3 T MRI machines. Autors: Steven McCabe;Jonathan Scott; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3541 - 3547 Publisher: IEEE
» A Novel Linearization Variant of Reliability Costs in the Optimal Scheduling Model
 Abstract:Reliability costs are used to evaluate the influence of large-scale wind power integration on security constrained unit commitment (SCUC), but the nonlinear expressions of reliability costs increase the complexity of the SCUC model. To address this issue, this letter presents a novel variant to exactly linearize the nonlinear expressions. Compared with the traditional approach, the proposed variant can reduce the number of binary variables, such that the computational performance of the SCUC model is significantly improved. Numerical results of the IEEE reliability test system verify the effectiveness of the proposed variant. Autors: Jiajun Lv;Tao Ding;Zhaohong Bie;Xifan Wang; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 4140 - 4142 Publisher: IEEE
» A Novel Mirror-Aided Non-Imaging Receiver for Indoor $2\times 2$ MIMO-Visible Light Communication Systems
 Abstract:Indoor visible light communication (VLC) systems are now possible because of advances in light emitting diode and laser diode technologies. These lighting technologies provide the foundation for multiple-input multiple-output (MIMO) data transmission through visible light. However, the channel matrix can be strongly correlated in indoor MIMO-VLC systems, preventing parallel data streams from being decoded. Here, in MIMO-VLC systems, we describe a mirror diversity receiver (MDR) design that reduces the channel correlation by both blocking the reception of light from one specific direction and improving the channel gain from light from another direction by utilizing a double-sided mirror deployed between the receiver’s photodetectors. We report on the channel capacity of the MDR system and the optimal height of its mirrors in terms of maximum channel capacity. We also derived analytic results on the effect of rotation on MDR’s performance. Based on numerical and experimental results, we show that the double-sided mirror has both constructive and destructive effects on the channel matrix. Our design can be used with previously described non-imaging systems to improve the performance of indoor VLC systems. Autors: Ki-Hong Park;Hassan Makine Oubei;Wael G. Alheadary;Boon S. Ooi;Mohamed-Slim Alouini; Appeared in: IEEE Transactions on Wireless Communications Publication date: Sep 2017, volume: 16, issue:9, pages: 5630 - 5643 Publisher: IEEE
» A Novel MMF Distribution Model for 3-D Analysis of Linear Induction Motor With Asymmetric Cap-Secondary for Metro
 Abstract:This paper develops a novel magnetomotive forces (mmfs) distribution model along the transverse direction for the 3-D analysis of linear induction motor, and it investigates the influence of a laterally asymmetric cap-secondary on the thrust, vertical force, lateral force, and efficiency in a prototype single-sided linear induction motor for linear metro. First, the mmf distribution model and its working conditions are defined, and the model is transferred into a mathematical model. Second, the air-gap flux and secondary eddy current in a prototype linear motor with a cap-secondary are obtained by a 3-D space harmonic analytical method. Third, the thrust, vertical force, lateral force, and efficiency of the test motor are analyzed with various lateral deflection, and the power factor in secondary is also presented. Finally, these results are experimentally verified by measurements on the test rig of the linear motor, and the comprehensive effect on the operating performance can be accurately calculated by the mmf model. Autors: Gang Lv;Dihui Zeng;Tong Zhou; Appeared in: IEEE Transactions on Magnetics Publication date: Sep 2017, volume: 53, issue:9, pages: 1 - 7 Publisher: IEEE
» A Novel Phase-Difference Fingerprinting Technique for Localization of Unknown Emitters
 Abstract:Localization of unknown emitters is crucial to tackle illegal radios or radio jammers which may cause harmful interference to other communication systems and disrupt services. Conventional fingerprint-based localization techniques that utilize received signal strength or channel information as location fingerprints may face problems when dealing with emitters whose parameters, such as center frequency, are unknown. In this paper, a novel localization algorithm utilizing the phase-difference between elements of an antenna array as location fingerprints is proposed. The training fingerprints are interpolated in the frequency and spatial domains before performing pattern matching with the unknown emitter's fingerprints. Localization accuracy was evaluated through ray-tracing and Monte Carlo simulations, and results indicate that the proposed technique achieved relatively good performance compared to other localization techniques. Autors: Azril Haniz;Gia Khanh Tran;Kentaro Saito;Kei Sakaguchi;Jun-ichi Takada;Daisuke Hayashi;Toshihiro Yamaguchi;Shintaro Arata; Appeared in: IEEE Transactions on Vehicular Technology Publication date: Sep 2017, volume: 66, issue:9, pages: 8445 - 8457 Publisher: IEEE
» A Novel Reactive Survivable Virtual Network Embedding Scheme Based on Game Theory
» A Novel Stator Structure for Active Axial Force Improvement in a One-Axis Actively Positioned Single-Drive Bearingless Motor
 Abstract:This paper presents a novel stator structure in an actively positioned bearingless motor with 1-degree of freedom. The single-drive bearingless motor concept has been adapted so that the torque and active axial force are regulated independently by the q- and d-axis currents, respectively, with only one three-phase inverter. The axial z-axis position is actively regulated, but the other axes (i.e., the radial and tilting movements) are passively stabilized. A novel stator structure has been proposed to enhance the active axial force. The stator is designed with soft magnetic composites. Experiments confirmed that the active axial force is enhanced by 50%. Autors: Hiroya Sugimoto;Itsuki Shimura;Akira Chiba; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4414 - 4421 Publisher: IEEE
» A Novel Subspace Based Method for Compensation of Multiple CFOs in Uplink MIMO OFDM Systems
 Abstract:The tri-linear data model for an arbitrary multi-user uplink multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) system comprising orthogonal frequency division multiplexing access users and co-channel (CC) users is formulated in this letter. A novel subspace-based method for multi-access interference cancellation and CC data separation in multi-user MIMO OFDM systems, utilizing the independent manifolds spanned by user’s carrier frequency offset matrix, is proposed in this letter. The system constraints under which the proposed subspace nulling method works are derived, which includes the under-determined cases, where minimum mean square error/zero forcing methods fail. Autors: Avik Santra;K. V. S. Hari; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 1993 - 1996 Publisher: IEEE
» A Novel Variable Flux Memory Machine With Series Hybrid Magnets
 Abstract:This paper proposes a novel variable flux memory (VFM) machine, in which the “constant” permanent magnet (CPM) with high coercive force and the “variable” PM (VPM) with low coercive force are alternatively located in the interior-PM rotor. Thus, the VPMs and CPMs are magnetically connected in series, with which the CPMs can assist the VPMs to withstand the unintentional demagnetization caused by armature reaction. Therefore, a high armature current can be applied to the machine. Meanwhile, the reluctance torque is retrieved. Thus, a high torque density can be obtained. Based on two-dimensional finite element analysis, first, the electromagnetic performance of the proposed VFM machine in two extreme magnetization states is evaluated in detail. Then, the demagnetization and remagnetization characteristics are investigated, in which the working points of VPMs are illustrated. Furthermore, the advantages of improved efficiency of the proposed VFM machine are demonstrated. A prototype machine is manufactured and tested to validate the predictions. Autors: Hao Hua;Z. Q. Zhu;Adam Pride;Rajesh P. Deodhar;Toshinori Sasaki; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4396 - 4405 Publisher: IEEE
» A Novel Wearable Apparatus to Measure Fingertip Forces in Manipulation Tasks Based on MEMS Barometric Sensors
 Abstract:Artificial tactile sensing is a challenging research topic in robotics, motor control, and rehabilitation engineering encompassing multi-disciplinary skills and different technologies. This paper presents the development of a wearable tactile thimble system using MEMS barometric sensors and flexible printed circuit board. Barometric sensors were carefully processed to make them able to transduce contact forces. Thumb, index, and medium fingers were equipped with an array of six sensing elements each, covering the central, lateral, and medial aspects of the fingertip. The sensor integration, signal read-out and processing, hardware architecture of the device, along with the calibration protocol, were described. The test results showed adequate sensitivity at very low forces with an almost linear transduction range up to about 4N (RMSE: 0.04N). Tests on object manipulation tasks highlighted the value of the proposed system demonstrating the ability of measuring both the force amplitude and contact points, demonstrating the suitability of barometric sensors for tactile applications. Autors: Pietro Cerveri;Mauro Quinzi;Dario Bovio;Carlo Albino Frigo; Appeared in: IEEE Transactions on Haptics Publication date: Sep 2017, volume: 10, issue:3, pages: 317 - 324 Publisher: IEEE
» A Novel Wiki-Based Remote Laboratory Platform for Engineering Education
 Abstract:With the unprecedented growth of e-learning, more and more new IT technologies are used to develop e-learning tools. As one of the most common forms of social computing, Wiki technology has been used to develop the collaborative and cooperative learning platform to support multiple users learning online effectively. In this paper, we propose a new software architecture to create a novel wiki-based remote laboratory platform by combining the advantages of both Wiki technology and remote laboratory technology. This platform is implemented based on a unified framework for remote laboratory development and an open source wiki software package, MediaWiki. To illustrate the effectiveness of this platform, two remote experiments, Smart Vibration Platform (SVP) and Proportional-Integral-Derivative (PID) motor speed control, are integrated into this platform. This new wiki-based remote laboratory has been used for teaching Mechanical Engineering courses and creating students’ assignments at the University of Houston. Autors: Ning Wang;Xuemin Chen;Qianlong Lan;Gangbing Song;Hamid R. Parsaei;Siu-Chun Ho; Appeared in: IEEE Transactions on Learning Technologies Publication date: Sep 2017, volume: 10, issue:3, pages: 331 - 341 Publisher: IEEE
» A Parallel Transportation Management and Control System for Bus Rapid Transit Using the ACP Approach
 Abstract:Bus rapid transit (BRT) has been proved to be an effective tool to improve mass transit services. However, BRT's adaptive operations like management and scheduling under different scenarios are too complicated to implement using traditional methods. The ACP approach, which is based on holism and complex system theory and consists of artificial systems (A), computational experiments (C) and parallel execution (P), offers an efficient new method to cope with these complex systems, including BRT. In this paper, the parallel transportation management and control system for BRT (PTMS-BRT) is presented, which is designed and implemented using the ACP approach. PTMS-BRT integrates such functions as BRT's monitoring, warning, forecasting, incident management, and real-time scheduling, to provide its operations smoother, safer, more efficient, and reliable. It has been piloted successfully in Guangzhou BRT to demonstrate it as another successful example of parallel transportation systems. Autors: Xisong Dong;Yuetong Lin;Dayong Shen;Zhengxi Li;Fenghua Zhu;Bin Hu;Dong Fan;Gang Xiong; Appeared in: IEEE Transactions on Intelligent Transportation Systems Publication date: Sep 2017, volume: 18, issue:9, pages: 2569 - 2574 Publisher: IEEE
» A Parity Structure for Scalable QC-LDPC Codes With All Nodes of Degree Three
 Abstract:A novel block triple-diagonal (BTD) parity structure with all nodes of degree three is proposed for quasi-cyclic (QC) low-density parity-check (LDPC) codes. The BTD structure without low node degree can effectively improve the error floor performance and, meanwhile, enable low complexity encoding. With this structure, we use a modulo-lifting technology to construct a family of QC-LDPC codes, which supports scalable code lengths with a simple and flexible encoding solution. The simulation results show that our coding schemes for short and moderate lengths achieve better performance in the error floor region. Autors: Xiaoning Wu;Ming Jiang;Chunming Zhao; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 1913 - 1916 Publisher: IEEE
» A Passive Imaging System for Geometry Measurement for the Plasma Arc Welding Process
 Abstract:Automatic and flexible geometry measurement of the weld pool surface can help better understand the complex welding processes and even provide feedback to better control this process. Most of existing imaging systems use an additional source of illumination to remove the light interference coming from the welding arc but it is usually costly. This paper introduces a novel low-cost optical-sensor-based monitoring system working under passive mode to monitor the wire + arc additive manufacture process, particularly for plasma arc welding. Initially, configurations and parameters of camera are investigated to achieve good visualization of weld pool. A novel camera calibration methodology using the nozzle of a computer numerical control (CNC) machine is then proposed for this imaging system, allowing estimation of the camera position with respect to the inspecting surface and its orientation in an easy-to-use approach. The verification tests show that the average error of the calibration is less than 1 pixel. As a case study, an image analysis routine is proposed to measure the width of the bead during the welding process. The results show that the proposed system is effective to measure the dimension of weld pool. Autors: Tomas Font comas;Chenglei Diao;Jialuo Ding;Stewart Williams;Yifan Zhao; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7201 - 7209 Publisher: IEEE
» A Physics-Based Vibrotactile Feedback Library for Collision Events
 Abstract:We present PhysVib: a software solution on the mobile platform extending an open-source physics engine in a multi-rate rendering architecture for automatic vibrotactile feedback upon collision events. PhysVib runs concurrently with a physics engine at a low update rate and generates vibrotactile feedback commands at a high update rate based on the simulation results of the physics engine using an exponentially-decaying sinusoidal model. We demonstrate through a user study that this vibration model is more appropriate to our purpose in terms of perceptual quality than more complex models based on sound synthesis. We also evaluated the perceptual performance of PhysVib by comparing eight vibrotactile rendering methods. Experimental results suggested that PhysVib enables more realistic vibrotactile feedback than the other methods as to perceived similarity to the visual events. PhysVib is an effective solution for providing physically plausible vibrotactile responses while reducing application development time to great extent. Autors: Gunhyuk Park;Seungmoon Choi; Appeared in: IEEE Transactions on Haptics Publication date: Sep 2017, volume: 10, issue:3, pages: 325 - 337 Publisher: IEEE
» A Power-Efficient Signal-Specific ADC for Sensor-Interface Applications
 Abstract:A novel signal-specific power-efficient analog-to-digital converter (ADC) is proposed for sensor-interface applications. Instead of digitizing each analog sample independently, the proposed ADC determines the digital code corresponding to each new input sample by digitizing the difference of two consecutive samples. Therefore, for the applications with low-varying input signals, such as image sensors and ECG readouts, the difference of two consecutive samples is much smaller than the ADC full-scale range for the majority of the input samples, the power consumption of the capacitive digital-to-analog converter, the comparator, and the digital circuits of the proposed ADC is saved due to reducing the ADC activity. The prototype was fabricated using a 0.18- CMOS technology. Measurement results of 1 V, 8 bit, 20 kS/s ADC confirm that for a 10-kHz input sine wave, the effective number of bits is 7 while the power consumption of the entire ADC is 1.12 . However, for the same sampling rate, the power consumption is only 106 nW for a low-varying 100-Hz input sine wave. Autors: Ehsan Rahiminejad;Mehdi Saberi;Reza Lotfi; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1032 - 1036 Publisher: IEEE
» A Power-Packed Issue
 Abstract:Welcome to the power and energy theme issue of IEEE Potentials. The following four articles will address highimpact topics in the world of power systems, written by energy experts from both industry and academia. I hope you enjoy reading them and gain a greater insight into this exciting field. Autors: Edvina Uzunovic;Juan Carlos Montero Quiros; Appeared in: IEEE Potentials Publication date: Sep 2017, volume: 36, issue:5, pages: 6 - 7 Publisher: IEEE
» A Predictive Model for IC Self-Heating Based on Effective Medium and Image Charge Theories and Its Implications for Interconnect and Transistor Reliability
 Abstract:Spatially resolved precise prediction of local temperature is essential to evaluate Arrhenius-activated interconnect (e.g., electromigration) and transistor reliability (e.g., NBTI, HCI, and TDDB). A 3-D finite-element modeling (FEM) do provide excellent results, but the calculation is too time-consuming for a structure that involves eight to ten layers of percolating interconnects, especially for fast turn-around reliability modeling. Here, an analytical model that can quickly/accurately determine will reduce the design time of self-heated modern IC. In this paper, we 1) develop a physics-based electrothermal compact model for ICs to predict based on the synthesis of effective medium theory, image charge theory, and Rent’s rule; 2) validate our model against 3-D FEM and experimental data; and 3) predict back-end-of-line (BEOL) reliability (i.e., electromigration at each layer) based on the temperature profile. Since our analytical model predicts changes in with any given IC’s configuration (e.g., interconnect wire length and number distribution, metal volume fraction in BEOL, heat sinks mechanisms, materials, and type of devices), it suggests new opportunities for optimization of performance and reliability of modern ICs. Autors: Woojin Ahn;Haojun Zhang;Tian Shen;Cathryn Christiansen;Patrick Justison;Sanghoon Shin;Muhammad Ashraful Alam; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3555 - 3562 Publisher: IEEE
» A Probabilistic Cost/Benefit Analysis of Transmission and Distribution Asset Expansion Projects
 Abstract:The electric power industry often uses cost/benefit analysis to evaluate system expansion projects. This letter discusses a probabilistic formulation of cost/benefit analysis to incorporate uncertainty in the data used for these studies. A Gaussian statistical model is used and an example is shown relating to distribution engineering. Autors: Gerald Thomas Heydt; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 4151 - 4152 Publisher: IEEE
» A Qualitative Study of Application-Level Caching
 Abstract:Latency and cost of Internet-based services are encouraging the use of application-level caching to continue satisfying users’ demands, and improve the scalability and availability of origin servers. Despite its popularity, this level of caching involves the manual implementation by developers and is typically addressed in an ad-hoc way, given that it depends on specific details of the application. As a result, application-level caching is a time-consuming and error-prone task, becoming a common source of bugs. Furthermore, it forces application developers to reason about a crosscutting concern, which is unrelated to the application business logic. In this paper, we present the results of a qualitative study of how developers handle caching logic in their web applications, which involved the investigation of ten software projects with different characteristics. The study we designed is based on comparative and interactive principles of grounded theory, and the analysis of our data allowed us to extract and understand how developers address cache-related concerns to improve performance and scalability of their web applications. Based on our analysis, we derived guidelines and patterns, which guide developers while designing, implementing and maintaining application-level caching, thus supporting developers in this challenging task that is crucial for enterprise web applications. Autors: Jhonny Mertz;Ingrid Nunes; Appeared in: IEEE Transactions on Software Engineering Publication date: Sep 2017, volume: 43, issue:9, pages: 798 - 816 Publisher: IEEE
» A Radio Frequency Sensor Array for Dielectric Constant Estimation of Multiphase Oil Flow in Pipelines
 Abstract:The measurement of the single phase portion in a multiphase flow is very important to oil and petrochemical industries. This paper presents a radio frequency (RF) sensor for dielectric constant estimation of two or three phase combinations of oil, water, and gas. The 28-port RF sensor was designed and optimized to operate at 250 MHz. Using the transmission coefficient of each RF sensor port, an equation was obtained for dielectric constant estimation by applying the least squares method. Three different static two phase combinations including oil–water, gas–water, gas–oil and three phase combination of oil–water–gas are experimentally validated with an average measured error percentages of 5.5%, 17.3%, 16% and 6.2%, respectively. A shake test for the three phase combination was performed to resemble an actual three phase flow and the average measured error was 9.3%. The proposed sensor can estimate two or three phase combinations of oil, water, and gas with an average error less than 10%. The proposed sensor is low cost, with low complexity and is the first to provide low error estimations to 2 or 3-phase static or dynamic flows. Autors: Muhammad Tayyab;Mohammad S. Sharawi;Abdelsalam Al-Sarkhi; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 5900 - 5907 Publisher: IEEE
» A Random Linear Network Coding Accelerator in a 2.4GHz Transmitter for IoT Applications
 Abstract:Random linear network coding (RLNC) is an emerging coding technique, which can provide several advantages in wireless networks, such as throughput gains, increased data robustness, and better utilization of network resources. In this paper, we present the first custom VLSI implementation of RLNC, integrated with an ultralow-power 2.4-GHz transmitter. We examine its energy efficiency and error recovery performance in the context of Internet of Things applications, and we perform experiments quantifying its benefits when it operates separately and jointly with physical layer forward error correction (FEC) codes, as a joint channel and network coding scheme. The chip is fabricated in a 65-nm CMOS process, occupies and consumes 580 pJ/bit for processing and transmitting data at 1 Mbps. The digital packet processor and encoder occupies , consists of an on-chip memory, a multi-rate convolutional encoder, and a RLNC accelerator with configurable redundancy, and consumes , operating at 0.4 V. For improved spectral efficiency, an on-chip pulse shaping filter is implemented, reducing side lobes by 28 dB while consuming . According to our over-the-air experiments, RLNC can provide an effective SNR improvement of 5.6 dB when combined with FEC rate 1/2, and 3.4 dB without FEC, at a packet error rate of . Autors: Georgios Angelopoulos;Arun Paidimarri;Muriel Médard;Anantha P. Chandrakasan; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2582 - 2590 Publisher: IEEE
» A Reactive Power Sharing Strategy of VSG Based on Virtual Capacitor Algorithm
 Abstract:In the islanded microgrid, distributed generators are controlled with virtual synchronous generator (VSG) strategy to simulate rotor inertia and droop characteristics of synchronous generators, in order to enhance the voltage and frequency support capabilities. Since the capacity and location distribution of each VSG is random, the VSG output impedance, line impedance and its capacity are mismatched, resulting in inaccurate sharing of reactive power. Based on the study of reactive power sharing schemes without communication and system parameters detection, and aiming at the contradiction between reactive power sharing error and voltage control accuracy of existing schemes, a reactive power sharing strategy based on virtual capacitor is proposed. The strategy simulates characteristics of paralleling capacitor at the VSG output terminal, and compensates the output voltage according to adaptive control of VSG output reactive power, thus to reduce reactive power sharing error, and improve the voltage control accuracy meanwhile. The design of virtual capacitor parameters and a two VSG parallel system stability with proposed strategy are analyzed in this paper. The correctness and effectiveness of the proposed strategy is verified by experiments. Autors: Haizhen Xu;Xing Zhang;Fang Liu;Rongliang Shi;Changzhou Yu;Renxian Cao; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7520 - 7531 Publisher: IEEE
» A Real-Time Gait Event Detection for Lower Limb Prosthesis Control and Evaluation
 Abstract:Lower extremity amputees suffer from mobility limitations which will result in a degradation of their quality of life. Wearable sensors are frequently used to assess spatio-temporal, kinematic and kinetic parameters providing the means to establish an interactive control of the amputee-prosthesis-environment system. Gait events and the gait phase detection of an amputee’s locomotion are vital for controlling lower limb prosthetic devices. The paper presents an approach to real-time gait event detection for lower limb amputees using a wireless gyroscope attached to the shank when performing level ground and ramp activities. The results were validated using both healthy and amputee subjects and showed that the time differences in identifying Initial Contact (IC) and Toe Off (TO) events were larger in a transfemoral amputee when compared to the control subjects and a transtibial amputee (TTA). Overall, the time difference latency lies within a range of ±50 ms while the detection rate was 100% for all activities. Based on the validated results, the IC and TO events can be accurately detected using the proposed system in both control subjects and amputees when performing activities of daily living and can also be utilized in the clinical setup for rehabilitation and assessing the performance of lower limb prosthesis users. Autors: H. F. Maqbool;M. A. B. Husman;M. I. Awad;A. Abouhossein;Nadeem Iqbal;A. A. Dehghani-Sanij; Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering Publication date: Sep 2017, volume: 25, issue:9, pages: 1500 - 1509 Publisher: IEEE
» A Real-Time Vibration Suppression Strategy in Electric Vehicles
 Abstract:In electric vehicles (EVs), the source of noise, vibration, and harshness (NVH) involves various components inside/outside of the vehicle. Besides the vibration from each NVH source, the resonances between multiple sources contribute even more significant vibrations. This paper proposes a generalized real-time suppression strategy to mitigate the coupling vibration during vehicle idling and cruising. Using a high-performance field-oriented-controlled electric motor drive, a relatively small amount of rotation velocity offset can be added to the traction motor to significantly reduce the resonant vibration with negligible impact to vehicular speed. In this paper, torsional and bending coupling vibrations between traction motor and driveline are investigated because these two are the most common forced vibrations due to resonances. The system is simulated using MATLAB/Simulink, and the results of the vibration suppression are presented. The strategy proposed in this paper presents a simple and robust way to suppress the coupling vibration in EVs with no additional hardware requirement. Autors: Qingchun Wang;Kaushik Rajashekara;Yijiang Jia;Jie Sun; Appeared in: IEEE Transactions on Vehicular Technology Publication date: Sep 2017, volume: 66, issue:9, pages: 7722 - 7729 Publisher: IEEE
» A Reconfigurable 16/32 Gb/s Dual-Mode NRZ/PAM4 SerDes in 65-nm CMOS
 Abstract:While four-level pulse amplitude modulation (PAM4) standards are emerging to increase bandwidth density, the majority of standards use simple binary non-return-to-zero (NRZ) signaling. This paper presents a dual-mode NRZ/PAM4 serial I/O SerDes which can support both modulations with minimum power and hardware overhead relative to a dedicated PAM4 link. A source-series-terminated transmitter achieves 1.2- output swing and employs lookup table control of a 31-segment output digital-to-analog converter (DAC) to implement 4/2-tap feed-forward equalization in NRZ/PAM4 modes, respectively. Transmitter power is improved with low-overhead analog impedance control in the DAC cells and a quarter-rate serializer based on a tri-state inverter-based mux with dynamic pre-driver gates. The receiver implements an NRZ/PAM4 decision feedback equalizer that employs one finite impulse response and two infinite impulse response taps for first post-cursor and long-tail inter-symbol interference (ISI) cancellation, respectively. First post-cursor ISI cancellation is performed in these comparators to optimize the design’s timing, while the remaining ISI taps are subtracted in a preceding current integration summer for improved sensitivity. Fabricated in GP 65-nm CMOS, the transceiver occupies 0.074 mm2 area and achieves 16 Gb/s NRZ and 32 Gb/s PAM4 operation at 10.9 and 5.5 mW/Gb/s while operating over channels with 27.6 and 13.5 dB loss at Nyquist, respectively. Autors: Ashkan Roshan-Zamir;Osama Elhadidy;Hae-Woong Yang;Samuel Palermo; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2430 - 2447 Publisher: IEEE
» A Refined Cluster-Analysis-Based Multibaseline Phase-Unwrapping Algorithm
 Abstract:As is well known, multibaseline phase unwrapping (PU) is put forward to overcome single-baseline PU in discontinuous-terrain-height estimation. This letter presents a refined algorithm based on the cluster analysis (CA)-based noise-robust efficient multibaseline PU algorithm proposed by H. Yu. The basic idea is to combine multiple interferometric synthetic aperture radar interferograms with different baseline lengths by a linear combination. The new interferograms after the linear combination increase the ambiguity heights. The number of resulting groups on the envelope of the intercept histogram is decreased and the distance between different intercept groups is widened. Compared with the conventional CA method, the significant advantage of the refined CA (RCA) algorithm is that it improves noise robustness when the intercept groups are densely distributed. The proposed RCA algorithm is validated using the simulated interferometric data. The results demonstrate that the noise robustness performance is better than that of the CA method. Autors: Zhibiao Jiang;Jian Wang;Qian Song;Zhimin Zhou; Appeared in: IEEE Geoscience and Remote Sensing Letters Publication date: Sep 2017, volume: 14, issue:9, pages: 1565 - 1569 Publisher: IEEE
» A Reliability-Aware Network Service Chain Provisioning With Delay Guarantees in NFV-Enabled Enterprise Datacenter Networks
 Abstract:Traditionally, service-specific network functions (NFs) (e.g., Firewall, intrusion detection system, etc.) are executed by installation-and maintenance-costly hardware middleboxes that are deployed within a datacenter network following a strictly ordered chain. NF virtualization (NFV) virtualizes these NFs and transforms them into instances of plain software referred to as virtual NFs (VNFs) and executed by virtual machines, which, in turn, are hosted over one or multiple industry-standard physical machines. The failure (e.g., hardware or software) of any one of a service chain’s VNFs leads to breaking down the entire chain and causing significant data losses, delays, and resource wastage. This paper establishes a reliability-aware and delay-constrained (READ) routing optimization framework for NFV-enabled datacenter networks. READ encloses the formulation of a complex mixed integer linear program (MILP) whose resolution yields an optimal network service VNF placement and traffic routing policy that jointly maximizes the achieved respective reliabilities of supported network services and minimizes these services’ respective end-to-end delays. A heuristic algorithm dubbed Greedy--shortest paths (GSP) is proposed for the purpose of overcoming the MILP’s complexity and develop an efficient routing scheme whose results are comparable to those of READ’s optimal counterparts. Thorough numerical analyses are conducted to evaluate the network’s performance under GSP, and hence, gauge its merit; particularly, when compared to existing schemes, GSP exhibits an improvement of 18.5% in terms of the average end-to-end delay as well as 7.4% to 14.8% in terms of reliability. Autors: Long Qu;Chadi Assi;Khaled Shaban;Maurice J. Khabbaz; Appeared in: IEEE Transactions on Network and Service Management Publication date: Sep 2017, volume: 14, issue:3, pages: 554 - 568 Publisher: IEEE
» A Review on Distribution System State Estimation
 Abstract:Transition to a sustainable energy environment results in aggregated generator and load dynamics in the distribution network. State estimation is a key function in building adequate network models for online monitoring and analyzes. The requirements of distribution system state estimation (DSSE) is becoming stringent because of the needs of new system modeling and operation practices associated with integration of distributed energy resources and the adoption of advanced technologies in distribution network. This paper summarizes the state-of-the-art technology, major hurdles, and challenges in DSSE development. The opportunities, paradigm shift, and future research directions that could facilitate the need of DSSE are discussed. Autors: Anggoro Primadianto;Chan-Nan Lu; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3875 - 3883 Publisher: IEEE
» A Robust Electrochemical CO2 Sensor Utilizing Room Temperature Ionic Liquids
 Abstract:Next generation CO2 gas sensors require an enhancement of sensitivity and invariance with regards to CO 2 detection and environmental factors. For this study, we report and discuss the effective application of room temperature ionic liquids (RTILs) toward the development of a stable electrochemical CO2 sensor that provides increased valuation toward commercial applications. We have investigated two RTILs on both gold and carbon paste electrodes on printed circuit boards over four different CO2 concentrations. We also have investigated another RTIL on a gold electrode for initial repeatability effects at two CO2 concentrations. Using electrochemical impedance spectroscopy and chronoamperometry, we compare and contrast the initial response behaviors for these RTILs for these sensors. This analysis has aided in the identification of robust combinations of RTIL/electrode toward environmental CO2 sensors. Autors: Edward W. Graef;Rujuta D. Munje;Shalini Prasad; Appeared in: IEEE Transactions on Nanotechnology Publication date: Sep 2017, volume: 16, issue:5, pages: 826 - 831 Publisher: IEEE
» A Robust Wide-Area Measurement-Based Damping Controller for Networks With Embedded Multiterminal and Multiinfeed HVDC Links
 Abstract:Control strategies for power swing damping which use wide-area feedback signals need to be robust to partial/complete loss of communication and changes in operating points and topology. In addition, they should have a positive effect on all controllable swing modes and ensure adequate stability margins to avoid destabilization of untargeted modes. This paper proposes a control strategy for multiple embedded dc links (multiterminal or multiinfeed), which has all these attributes and is inherently able to provide wideband damping. The strategy uses only a limited set of nonlocal signals. These signals may be directly communicated to the dc links without having to be centrally collated with other system-wide measurements, thereby reducing communication delays. The strategy can easily be adapted during power system operation to achieve targeted damping of the critical swing modes. Autors: Prashant Agnihotri;A. M. Kulkarni;Aniruddha M. Gole;Brian A. Archer;Tony Weekes; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3884 - 3892 Publisher: IEEE
» A SAW-Less 2.4-GHz Receiver Front-End With 2.4-mA Battery Current for SoC Coexistence
 Abstract:A 2.4-GHz receiver for short-range communications with +6 dBm out-of-band IIP3 and only 2.4-mA battery current is presented. The single-ended input is coupled through an integrated transformer to a push–pull differential low-noise transconductance amplifier (LNTA) followed by a current mode passive mixer that drives a single-opamp biquad trans-impedance amplifier. This approach ensures sufficient linearity to enable coexistence with large out-of-band interference arising from other on-chip/on-board transceivers. An efficient block stacking technique is proposed to minimize the current drawn from a standard 1.8-V supply. The first stages of the two opamps used in the I and Q baseband Rauch filters are placed above and below the LNTA core, thereby sharing its dc current. Two active inductors isolate the RF and baseband signal paths. Several techniques are used to limit the impact of the 1/f noise of the RF blocks on the receiver and to minimize nonlinearities due to interactions between blocks sharing the same current. The entire receive signal path draws 2.4 mA from a 1.8-V supply and has a noise figure of 7.8 dB at 2.4 GHz and an out-of-band 1-dB compression point of −5 dBm. The chip, implemented in 28-nm LP CMOS, occupies an active area of 0.4 mm2. Autors: Matteo Ramella;Ivan Fabiano;Danilo Manstretta;Rinaldo Castello; Appeared in: IEEE Journal of Solid-State Circuits Publication date: Sep 2017, volume: 52, issue:9, pages: 2292 - 2305 Publisher: IEEE
» A Scalable High-Performance Priority Encoder Using 1D-Array to 2D-Array Conversion
 Abstract:In our prior study of an -bit priority encoder (PE), a so-called one-directional-array to two-directional-array conversion method is deployed to turn an -bit input data into an -bit matrix. Following this, an -bit PE and an -bit PE are employed to obtain a row index and column index. From those, the highest priority bit of -bit input data is achieved. This brief extends our previous work to construct a scalable architecture of high-performance large-sized PEs. An optimum pair of (, ) and look-ahead signal are proposed to improve the overall PE performance significantly. The evaluation is achieved by implementing a variety of PEs whose varies from 4-bit to 4096-bit in 180-nm CMOS technology. According to post-place-and-route simulation results, at PE size of 64 bits, 256 bits, and 2048 bits the operating frequencies reach 649 MHz, 520 MHz, and 370 MHz, which are 1.2 times, 1.5 times, and 1.4 times, as high as state-of-the-art ones. Autors: Xuan-Thuan Nguyen;Hong-Thu Nguyen;Cong-Kha Pham; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1102 - 1106 Publisher: IEEE
» A Self-Adaptive Time-Based MPPT With 96.2% Tracking Efficiency and a Wide Tracking Range of 10 $\mu$ A to 1 mA for IoT Applications
 Abstract:This paper presents a novel ultra-low power maximum power point tracking (MPPT) technique with a wide tracking range. An indirect, non-interrupting approach using a novel timing-based algorithm is proposed. The proposed MPPT technique is self-adaptive and applicable to the various types of photovoltaic cells without external reconfiguration or the change of passive components. In addition, a variable gain is employed in the one-hot barrel shift register to reduce the transient response time. A test chip was fabricated in 65-nm CMOS technology. The test chip can harvest energy with the input voltage range of 0.4 V to 1.7 V and the step response time of less than 100 ms at the minimum supply voltage of 0.8 V. The tracking efficiency is up to 96.2% when supplied by a photovoltaic micro-cell array using an irradiation range of 200 lux to 1000 lux. Autors: Karim Rawy;Felix Kalathiparambil;Dominic Maurath;Tony Tae-Hyoung Kim; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2334 - 2345 Publisher: IEEE
» A Shock Tube Experimental System for Communication Performance Evaluation Under the Time-Varying Plasma Flow Channel
 Abstract:Plasma sheath can severely affect the electromagnetic waves and lead to the radio blackout problem. Existing simulation works on the influence of plasma on communications, either failed to illustrate the high dynamics of the plasma or suffered from high computational complexity. In this paper, we propose an experimental system based on a shock tube to evaluate the communication performance over the plasma channel. In order to compare the performance of different modulation modes simultaneously, we initiatively mixed frequency-shift keying (FSK), pulse-position modulation, and quadrature phase-shift keying (QPSK) together in the transmission signal. Since the duration of the plasma generated by the shock tube is short in each experiment instance, we employ the achievable rate to evaluate the communication performance. Specifically, according to our experimental results, the communication performance of FSK is the best and most stable, while the QPSK is the worst and most unstable, indicating that the plasma channel has the greatest impact on the phase domain compared with the frequency domain and the time domain. Finally, the nonstationary and high dynamic characteristics of the plasma channel are verified in our designed experiment. Autors: Xuantao Lyu;Chunxiao Jiang;Wei Feng;Ning Ge; Appeared in: IEEE Transactions on Plasma Science Publication date: Sep 2017, volume: 45, issue:9, pages: 2450 - 2459 Publisher: IEEE
» A Shoelace Antenna for the Application of Collision Avoidance for the Blind Person
 Abstract:A shoelace antenna for the application of collision avoidance for the blind person is proposed for the first time. A thin flexible metal wire is used to fabricate the antenna, which can run along with the shoelace without destroying the shoe or adding extra big structures. According to the investigations, to put the feeding probe at the bottom of the cross point is better than the locations around the string bowknot. To make the shoelace tighter or looser will influence the performance with an affordable variation. The effect of the biological tissues has been taken into account during the performance evaluation of the antenna. The measured fractional bandwidth is 11% with a resonance of 2.43 GHz in the ISM Band. The main lobe of the antenna points to the upper front direction with an angle of about 20°, which is suitable for the detecting of the anterior obstacles when walking. The measured results indicate reasonable performance for the shoelace antenna to serve as a tool for the blind person. Autors: Gaosheng Li;Zhihao Tian;Gui Gao;Liang Zhang;Meng Fu;Yuwei Chen; Appeared in: IEEE Transactions on Antennas and Propagation Publication date: Sep 2017, volume: 65, issue:9, pages: 4941 - 4946 Publisher: IEEE
» A Simulator Study Comparing Characteristics of Manual and Automated Driving During Lane Changes of Long Combination Vehicles
 Abstract:This paper presents a back-to-back performance comparison of lane-change maneuvers using two automated driving approaches and manual driving. The lane changes were conducted in a moving-base truck driving simulator using an A-double long combination vehicle. One of the automated driving approaches was based on driver model control and the other used optimization-based control. The comparison addresses lane change and braking, both initiation and execution, from the perspective of driver behavior and defined characteristic variables. We also discuss combined braking and steering behavior using a moderately safety-critical lane-change scenario. The purpose of this paper is to improve driving automation in early development by comparing and learning from professional truck drivers to enable higher driver acceptance. Autors: Peter Nilsson;Leo Laine;Bengt Jacobson; Appeared in: IEEE Transactions on Intelligent Transportation Systems Publication date: Sep 2017, volume: 18, issue:9, pages: 2514 - 2524 Publisher: IEEE
» A Single-Chip Image Sensor Node With Energy Harvesting From a CMOS Pixel Array
 Abstract:This paper presents a single-chip image sensor node with energy harvesting from the pixel array. The design includes a pixel array that can be reconfigured to form an on-chip photovoltaic cell to harvest energy. An on-chip power management unit harvests energy from the pixel array, and delivers multiple regulated output voltage domains to power the sensor, image processor, and memory. The image processor is a low-overhead moving object detection unit to reduce the volume of transmitted data. The proposed sensor node is implemented on a single die in 130-nm technology. The pixel array demonstrates the peak harvested power of . The power dissipation of sensor is reduced by utilizing low-power circuit techniques, including block-level pipelining, power gating, and low-voltage memory. The system can be self-powered to process a frame at every 7 s. We discuss design approaches for improving the self-power performance. The noise characteristic of the reconfigurable sensor is analyzed, and the need for noise-robust moving object detection is evaluated for better image quality and improved self-power performance. Autors: Jong Hwan Ko;Mohammad Faisal Amir;Khondker Zakir Ahmed;Taesik Na;Saibal Mukhopadhyay; Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers Publication date: Sep 2017, volume: 64, issue:9, pages: 2295 - 2307 Publisher: IEEE
» A Single-Loop Approach for Time-Variant Reliability-Based Design Optimization
 Abstract:In the process of long-term use, the uncertainty of an engineering structure often presents time-variant or dynamic characteristics due to the influence of stochastic loads and material performance degradations. In such a situation, the structural design optimization will involve an important problem of time-variant reliability-based design optimization (TRBDO). Performing TRBDO involves a nested optimization, which will lead to extremely low computational efficiency. In this paper, a single-loop approach (SLA) is proposed to convert the nested optimization in TRBDO into a sequence iterative process composed of the time-variant reliability analysis (TRA), constraint discretization, and design optimization. In each iteration step, the TRA method based on stochastic process discretization is first used to calculate the time-variant reliability of constraints; second, through introducing the concept of the target reliability index of discretized time period and proposing the corresponding algorithm, each time-variant constraint is discretized into a series of time-invariant constraints to formulate a conventional reliability-based design optimization problem. The approach exhibits a good comprehensive performance in terms of efficiency and convergence. The validity and practicality of the SLA are validated by two numerical examples and a design problem for the chassis of a self-balancing vehicle. Autors: Zhi Liang Huang;Chao Jiang;Xiao Ming Li;Xin Peng Wei;Teng Fang;Xu Han; Appeared in: IEEE Transactions on Reliability Publication date: Sep 2017, volume: 66, issue:3, pages: 651 - 661 Publisher: IEEE
» A Single-Phase Buck Matrix Converter With High-Frequency Transformer Isolation and Reduced Switch Count
 Abstract:In this paper, a new type of matrix converter (MC) also called a single-phase high-frequency transformer isolated (HFTI) buck MC is proposed. The proposed converter can provide step-down operation of the input voltage with various types of output voltages such as in-phase and out-of-phase output voltages, rectified (or positive) output voltage, and output voltage with step-changed frequency. By incorporating HFT isolation, the proposed MC saves an extra bulky line frequency transformer, which is required for the conventional MCs to provide electrical isolation and safety, when used in application such as dynamic voltage restorers, etc. Two different circuit variations of the proposed HFTI MC are presented with and without continuous output currents, with the latter having less passive components. The safe-commutation strategy is also employed for the proposed HFTI MC to provide current path for the inductor during dead-time, which avoids switch voltage spikes without adding any snubber circuits. The operation principle and circuit analysis of the proposed MC are presented, and switching strategies are also developed to obtain various output voltages. Moreover, a prototype of the proposed MC is fabricated, and experiments are performed to produce in-phase/out-of-phase and rectified output voltages, and output voltage with step-changed frequency. Autors: Hafiz Furqan Ahmed;Honnyong Cha;Ashraf Ali Khan; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 6979 - 6988 Publisher: IEEE
» A Smart Electrostatic Sensor for Online Condition Monitoring of Power Transmission Belts
 Abstract:Online condition monitoring of power transmission belts is essential to keep industrial belt-driven equipment functioning smoothly and reliably. This paper presents a smart electrostatic sensor that monitors belt motion through detection of static charge on the belt. A theoretical model is established using the method of moments for calculation of induced charge on strip-shaped electrodes placed in the vicinity of a belt moving both axially and transversely. The sensor unit converts the induced charge into proportional voltage signals using charge amplifiers and measures belt speed and vibration through cross correlation and spectral analysis, respectively. The performance of the smart electrostatic sensor is validated against a photoelectric rotary encoder and a laser displacement sensor. Comparative experimental results show that the belt speed can be measured with a relative error within ±2% over the range 1.7–15.5 m/s. The electrostatic sensor is capable of measuring the frequencies of transverse vibration accurately. Although absolute displacement cannot be measured due to the uncertain level of charge on the belt, the measurement results of relative vibration magnitudes for different modes and at different belt speeds are reasonably accurate. Autors: Yonghui Hu;Shuai Zhang;Yong Yan;Lijuan Wang;Xiangchen Qian;Lu Yang; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7313 - 7322 Publisher: IEEE
» A Snapback-Free Fast-Switching SOI LIGBT With Polysilicon Regulative Resistance and Trench Cathode
 Abstract:A snapback-free fast-switching lateral insulated-gate bipolar transistor (LIGBT) with low power loss and high ruggedness is proposed and investigated by simulation. The proposed device features a polysilicon regulative resistance (PR) and a trench cathode (TC), named PRTC LIGBT. The PR is employed to not only suppress the snapback effect by regulating the voltage drop between P+ anode and N-buffer, but also improve the tradeoff between the on-state voltage drop ( and turn-off loss (. The TC widens the hole current path and decreases the distributed resistance under N+ cathode, and thus delivers a high latch-up ruggedness. Additionally, the PRTC LIGBT exhibits a blocking characteristic irrelevant to P+ anode concentration (NA), like a p-i-n diode (P-well, N-drift, and N-buffer), owing to its undepleted N-buffer region. Simulation results show that the PRTC LIGBT eliminates the snapback and reduces the by 28% compared to the segmented trenches in the anode (STA) region LIGBT. Its short-circuit time is prolonged by 53% and 40% compared to those of the STA LIGBT and PR LIGBT (without TC), respectively. Autors: Linhua Huang;Xiaorong Luo;Jie Wei;Kun Zhou;Gaoqiang Deng;Tao Sun;Dongfa Ouyang;Diao Fan;Bo Zhang; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3961 - 3966 Publisher: IEEE

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