Electrical and Electronics Engineering publications abstract of: 02-2018 sorted by title, page: 4

» An Optimal Design Methodology for Yield-Improved and Low-Power Pipelined ADC
Abstract:
An energy-efficient, high-performance, and yield-improved analog to digital converter (ADC) design using a multi-objective evolutionary algorithm is demonstrated. The proposed ADC design algorithm incorporates several techniques to enable simultaneous improvement of yield and performance. With the same accuracy, the proposed approach can achieve a significant reduction of computational burden compared with the modified Monte-Carlo (MC)-based yield improvement methods integrating Latin-hypercube sampling or trimmed-sample MC. A prototype chip based on the proposed design is fabricated in a 0.13- CMOS process at 150 MS/s. The results show the ADC achieves an SFDR of 65.48 dB and SNDR of 58.15 dB while dissipating 12 mW from a 1-V power supply. The results also yield a figure of merit of 121 fJ/conversion step.
Autors: Nahid Mirzaie;Gyung-Su Byun;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Feb 2018, volume: 31, issue:1, pages: 130 - 135
Publisher: IEEE
 
» An Optimization Model for Electric Vehicle Battery Charging at a Battery Swapping Station
Abstract:
A new model for a viable battery swapping station is proposed to minimize its cost by determining the optimized charging schedule for swapped electric vehicle (EV) batteries. The aim is to minimize an objective function considering three factors: the number of batteries taken from stock to serve all the swapping orders from incoming EVs, potential charging damage with the use of high-rate chargers, and electricity cost for different time period of the day. A mathematical model is formulated for the charging process following the constant-current/constant-voltage charging strategy. An integrated algorithm is proposed to determine an optimal charging schedule, which is inspired by genetic algorithm, differential evolution, and particle swarm optimization. A series of simulation studies are executed to assess the feasibility of the proposed model and compare the performance between the proposed algorithm and the typical evolutionary algorithms.
Autors: Hao Wu;Grantham Kwok Hung Pang;King Lun Choy;Hoi Yan Lam;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 881 - 895
Publisher: IEEE
 
» An Optimized Drude's Equation For Polarization Measurement in the Visible Region and Concentrations Estimation
Abstract:
Drude's equation, a classical equation, can be used to express the properties of optic polarization. In the paper, an optimized two-term Drude's equation is introduced for expressing the specific rotation. The optical rotation angle for each wavelength is measured by a charge-coupled device. In order to verify the precision and versatility of the equation, we compare the obtained specific rotation with published analysis at a wavelength of 589.3 nm. Moreover, the two-term Drude's equation is translated into calculate the approximatively individual concentration of the molecules in aqueous solution. The calculation is based on the linear functional relation and fitting parameters of total rotation without knowing the ranges of concentrations and setting constraints. The viability and flexibility of this method demonstrate the potential applications in optics.
Autors: Yu Lei;Hongzhi Jia;Xun Xu;Shixin Jiang;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 9
Publisher: IEEE
 
» An SNR-Assured Anti-Jamming Routing Protocol for Reliable Communication in Industrial Wireless Sensor Networks
Abstract:
Industrial wireless sensor networks (IWSNs) are an expansion of the Internet of Things paradigm that fully exploits the collective intelligence of smart nodes in industrial processes. The data acquisition of IWSNs in harsh industrial environments is susceptible to transmission failures and time delay while being strict in the performance of reliability and timeliness. This article proposes an SNR-assured anti-jamming clustering routing (SA-AJCR) protocol to address the problem of data transmission in an environment of high ambient noise and complex electromagnetic interference. To ease the influence of the industrial field on wireless communication, the irregular radio range of each node is modeled through field testing, and then its communication range is artificially constrained to ensure that each signal is received under a satisfying SNR. Through mapping out an approximation of jammed areas at the cluster level, SA-AJCR enables IWSNs to be tolerant of node or link failure caused by jamming. Routing paths can be adjusted to greedily bypass the mapped jammed regions in the network without interrupting the data transmission or overriding the CSMA limitation. The simulation results demonstrate that the proposed protocol is effectively able to provide high packet delivery ratio in hostile electromagnetic environments with the existence of jammers.
Autors: Li Liu;Guangjie Han;Sammy Chan;Moshen Guizani;
Appeared in: IEEE Communications Magazine
Publication date: Feb 2018, volume: 56, issue:2, pages: 23 - 29
Publisher: IEEE
 
» An Ultra-Wide-Band Tightly Coupled Dipole Reflectarray Antenna
Abstract:
A novel ultra-wide-band tightly coupled dipole reflectarray (TCDR) antenna is presented in this paper. This reflectarray antenna consists of a wideband feed and a wideband reflecting surface. The feed is a log-periodic dipole array antenna. The reflecting surface consists of unit cells. Each cell is composed of a tightly coupled dipole and a delay line. The minimum distance between adjacent cells is 8 mm, which is about 1/10 wavelength at the lowest operating frequency. By combining the advantages of reflectarray antennas and those of tightly coupled array antennas, the proposed TCDR antenna achieves ultra-wide bandwidth with reduced complexity and fabrication cost. A method to minimize the phase errors of the wideband reflectarray is also developed and the concept of equivalent distance delay is introduced to design the unit cell elements. To verify the design concept, a prototype operating from 3.4 to 10.6 GHz is simulated and fabricated. Good agreement between simulated and measured results is observed. Within the designed frequency band, the radiation pattern of the TCDR antenna is stable and the main beam of the antenna is not distorted or split. The side lobe levels of the radiation patterns are below −11.7 dB in the entire operating band. It is the first time a tightly coupled reflectarray is reported.
Autors: Wenting Li;Steven Gao;Long Zhang;Qi Luo;Yuanming Cai;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 533 - 540
Publisher: IEEE
 
» Analog Frontend for Tribo-Current-Based Fly-Height Sensor for Magnetic Hard Disk Drive
Abstract:
This paper presents an analog front end for measuring the triboelectric current flow between the triboelectric current sensor attached to the magnetic recording head and the media in a hard-disk-drive (HDD) system. The magnitude of the triboelectric current serves as a measure of the proximity between the head and the media and can be optimized for better performance in the next generation HDDs. The analog front end employs a novel current-divert circuit to create two separate signal paths with high and low gain that together provide a linear measure of the triboelectric current over a large dynamic range. A 42.6- dc-coupled, low leakage transimpedance amplifier is designed for the high gain path. It employs an area-efficient, floating, gate-voltage controlled MOS resistor with a novel open-loop temperature compensation scheme. A gain variation of <10% and an input current offset drift of < ±35 pA are measured over a temperature range of −40 °C to 120 °C. With the help of the low gain path, an overall input dynamic range of tens of picoamps to 50 nA is achieved. The high accuracy and large dynamic range measurement of tribocurrent serves the dual purpose of accurate fly-height estimation and tracking of the topography of the hard-disk media.
Autors: Arup Polley;Pankaj Pandey;Bryan E. Bloodworth;Costin Cazana;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 556 - 566
Publisher: IEEE
 
» Analog Models Manipulation for Effective Integration in Smart System Virtual Platforms
Abstract:
Analog components are fundamental blocks of smart systems, as they allow a tight interaction with the environment, in terms of both sensing/actuation and communication. This impacts on the design of the overall system, and mainly on the validation phase, that thus requires the joint simulation of digital and analog aspects. In this scenario, this paper proposes the automatic conversion of analog models to C++-based languages, to remove the overhead of co-simulation with traditional virtual platform tools. The proposed methodology allows to convert a given analog description to either: 1) a fully equivalent description or 2) an abstract representation for faster simulation which models only the aspects of interest. Effectiveness and correctness have been proved on a number of case studies that highlight the effectiveness and potentiality of the proposed methodology.
Autors: Michele Lora;Sara Vinco;Enrico Fraccaroli;Davide Quaglia;Franco Fummi;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Feb 2018, volume: 37, issue:2, pages: 378 - 391
Publisher: IEEE
 
» Analysis and Background Self-Calibration of Comparator Offset in Loop-Unrolled SAR ADCs
Abstract:
In conventional charge redistribution successive approximation register (SAR) ADCs that use a single comparator, the comparator offset causes no distortion but a dc shift in the transfer curve. In loop-unrolled (LU) SAR ADCs, on the other hand, mismatched comparator offset voltages introduce input-level-dependent errors to the conversion result, which deteriorates the linearity and limits the resolution. Still, the literature lacks a quantitative analysis on this phenomenon, and the resolution of most reported SAR ADCs of this kind, until recently, has been limited to 6 bit. In this paper, we analyze the effects of comparator offset voltage mismatch in LU-SAR ADCs, and establish the quantitative relation between individual offsets and the signal-to-noise-and-distortion ratio (SNDR) and the effective-number-of-bits. A statistical linearity model is proposed for yield estimation. Finally, an on-line deterministic calibration technique for auto-zeroing dynamic comparator offset is presented to treat the offsets mismatch and improve linearity. A 150-MS/s 8-bit LU-SAR ADC is fabricated in a 130-nm CMOS technology to validate the concept. The measured result shows that the calibration improves the SNDR from 33.7 to 42.9 dB. The ADC consumes from a 1.2-V supply with a figure-of-merit of 37.5 fJ/conv-step.
Autors: Shaolong Liu;Taimur Rabuske;Jeyanandh Paramesh;Lawrence Pileggi;Jorge Fernandes;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 458 - 470
Publisher: IEEE
 
» Analysis and Behavioral Modeling of Monolithic Digital Potentiometers
Abstract:
This paper focuses on analysis and modeling of complementary metal-oxide semiconductor (CMOS) resistive digital-to-analog converter (RDAC) potentiometers based on string digital-to-analog converter or Kelvin divider architecture. The model is developed by using very-high hardware description language (VHDL) analog and mixed-signal language, and accurately simulates basic static and dynamic parameters, integral nonlinearity, terminal voltage operating range, and leakage current at various operational modes for linear and nonlinear changing of the middle point (wiper). The model is implemented in the SystemVision simulation platform, using a style combining structural and behavioral elements. For verification of the model parameters are extracted for single-stage AD5235 and triple-stage AD5143 RDACs from analog devices as examples. The workability of the proposed models is validated by simulation and experimental testing of sample digitally controlled analog circuits. The comparative analysis shows that the achieved relative error, between the simulation and the experimental results at the maximum value of the nominal resistance equal to , is less than 5%. Moreover, an error of 5% is quite acceptable, considering the technological tolerances of the parameters.
Autors: Ivailo M. Pandiev;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 416 - 425
Publisher: IEEE
 
» Analysis and demonstration of network utilization improvement through format-agnostic multi-channel wavelength converters
Abstract:
The effectiveness of using all-optical wavelength converters (AO-WCs) to improve optical network utilization is evaluated by performing both network simulations and experiments. The employed AO-WCs enable format-agnostic and multi-channel operations, in which the wavelengths of multiple input channels are simultaneously shifted by the same amount. Such unique features are not available in conventional optical-electrical-optical-conversion-based wavelength converters (OEO-WCs). Network simulations show that the wavelength conversion can double the network utilization (the carried traffic), while the number of required wavelength converters can be significantly reduced by 60% by employing AO-WCs instead of OEO-WCs. In addition, simulation results confirm the importance of AO-WC cascadability for achieving low blocking probabilities. Our simulation analysis also identifies an optimum AO-WC specification value, the maximum wavelength shift, for maximizing sharing of the installed AO-WCs. In the experiment, the performance of a prototyped AO-WC is evaluated under a realistic network setup employing a wavelength-selective-switch-based optical node installing the AO-WC and fiber transmission lines. Wavelength division multiplexing signals of different modulation formats, including dual-polarization quadrature phase shift keying (DP-QPSK), dual-polarization 16 quadrature amplitude modulation (DP-16QAM), and on-off keying (OOK), spanning over a 1000 GHz bandwidth are successfully shifted simultaneously by 1400 GHz or 200 GHz without significant signal quality degradation, confirming the guard-band-less, multi-channel, and modulation-format/ line-rate-agnostic capabilities of the AO-WC.
Autors: Kiyo Ishii;Takashi Inoue;Inwoong Kim;Xi Wang;Hung Nguyen Tan;Qiong Zhang;Tadashi Ikeuchi;Shu Namiki;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Feb 2018, volume: 10, issue:2, pages: A165 - A174
Publisher: IEEE
 
» Analysis and Design of a Broadband Multifeed Tightly Coupled Patch Array Antenna
Abstract:
In this letter, a multifeed tightly coupled patch array antenna capable of broadband operation is analyzed and designed. First, an antenna array composed of infinite elements with each element excited by a feed is proposed. To produce specific polarized radiation efficiently, a new patch element is proposed, and its characteristics are studied based on a 2-port network model. Full-wave simulation results show that the infinite antenna array exhibits both a high efficiency and desirable radiation pattern in a wide frequency band (10 dB bandwidth) from 1.91 to 5.35 GHz (94.8%). Second, to validate its outstanding performance, a realistic finite 4 × 4 antenna prototype is designed, fabricated, and measured in our laboratory. The experimental results agree well with simulated ones, where the frequency bandwidth (VSWR < 2) is from 2.5 to 3.8 GHz (41.3%). The inherent compact size, light weight, broad bandwidth, and good radiation characteristics make this array antenna a promising candidate for future communication and advanced sensing systems.
Autors: Xi Yang;Pei-Yuan Qin;Yao Liu;Ying-Zeng Yin;Yingjie Jay Guo;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 217 - 220
Publisher: IEEE
 
» Analysis and Design of a Passive Receiver Front-End Using an Inductive Antenna Impedance
Abstract:
This paper presents the analysis and design of a passive front-end (PFE) for low-power receivers. The freedom of the antenna impedance is observed and exploited to propose an inductive-antenna-based PFE. Analytical methods for the desired signal transfer and noise behavior of the proposed PFE are presented to offer insight into the proposed technique and facilitate the design. The analysis suggests that the inductive-antenna-based PFE offers higher voltage gain and lower noise figure than a standard -based PFE does, which is confirmed by simulations. The proposed PFE and a baseband bandpass amplifier are designed in 0.18- CMOS technology for the 402–405 MHz band of the IEEE 802.15.6 WBAN standard. Their combination exhibits a passive voltage gain of 11.6 dB, a NF of 14.7 dB, and an in-band IIP3 of 3.6 dBm, while dissipating 1.1 mW from a 1.2 V supply.
Autors: Yao Liu;Wouter A. Serdijn;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 733 - 744
Publisher: IEEE
 
» Analysis and Design of Broadband LC-Ladder FET LNAs Using Noise Match Network
Abstract:
A noise match network for the LC-ladder input network of a broadband inductively source-degenerated common-source (CS) field effect transistor (FET) low-noise amplifier (LNA) is established through noise transformation matrix to derive the noise parameters of a broadband LNA. Analytical formulas for the noise factors of a CS FET LNA with a three-section LC-ladder input network are thus obtained based on the design algorithm of optimal noise and input match developed in this paper. Two 3.7–10.5 GHz two-stage LNAs of the same topology are demonstrated using 0.15- pHEMT technology to validate the design methodology. One LNA has all the fully integrated inductors and the other uses two on-chip inductors replaced by two high-Q bondwire inductors for better noise performance. The measurement results show 11-dB power gain with 2.1-dB noise figure for the LNA with the fully integrated inductors and 11-dB power gain with 1.6-dB noise figure for the LNA with two bondwire inductors, respectively.
Autors: Yu-Chih Hsiao;Chinchun Meng;Meng-Che Li;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Feb 2018, volume: 66, issue:2, pages: 987 - 1001
Publisher: IEEE
 
» Analysis and Design of Functionally Weighted Single-Input-Rule-Modules Connected Fuzzy Inference Systems
Abstract:
The single-input-rule-modules (SIRMs) connected fuzzy inference method can efficiently solve the fuzzy rule explosion phenomenon, which usually occurs in the multivariable modeling and/or control applications. However, the performance of the SIRMs connected fuzzy inference system (SIRM-FIS) is limited due to its simple input–output mapping. In this paper, to further enhance the performance of SIRM-FIS, a functionally weighted SIRM-FIS (FWSIRM-FIS), which adopts multivariable functional weights to measure the important degrees of the SIRMs, is presented. Then, in order to show the fundamental differences of the SIRMs methods, properties of the traditional SIRM-FIS, the type-2 SIRM-FIS (T2SIRM-FIS), the functional SIRM-FIS (FSIRM-FIS), the SIRMs model with single-variable functional weights (SIRM-FW), and FWSIRM-FIS are explored. These properties demonstrate that the proposed FWSIRM-FIS has more general and complex input–output mapping than the existing SIRMs methods. Such properties theoretically guarantee that better performance can be achieved by FWSIRM-FIS. Furthermore, based on the least-squares method, a novel data-driven optimization method is presented for the parameter learning of FWSIRM-FIS. It can also be used to optimize the parameters of SIRM-FIS, T2SIRM-FIS, FSIRM-FIS, and SIRM-FW. Due to the properties of the least-squares method, the proposed parameter learning algorithm can overcome the drawbacks of the gradients-based parameter learning methods and obtain both smallest training errors and smallest parameters. Finally, to show the effectiveness and superiority of FWSIRM-FIS and the proposed optimization method, six examples and detailed comparisons are given. Simulation results show that FWSIRM-FIS can obtain better performance than the other SIRMs methods, and, compared with some well-known methods, FWSIRM-FIS can achieve similar or better performance but has much less parameters and faster training speed.
Autors: Chengdong Li;Junlong Gao;Jianqiang Yi;Guiqing Zhang;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Feb 2018, volume: 26, issue:1, pages: 56 - 71
Publisher: IEEE
 
» Analysis and Design of Triple-Rotor Axial-Flux Spoke-Array Vernier Permanent Magnet Machines
Abstract:
This paper focuses on the analysis and design of a triple-rotor axial-flux spoke-array vernier permanent magnet (TR-AFSAVPM) machine. By cooperating with spoke-array rotor and coil-wounded winding, power factor and torque density of the proposed machine are much improved and its copper utilization is reduced comparing with conventional vernier machines. First, the machine structure and its operation principles are reviewed. After that, analytical equations of its back-electromotive force and torque are derived to reveal the machine characteristics. Based on both quasi-3-D finite element analysis (FEA) and 3-D FEA, its high torque density performance is verified and a set of optimized machine sizing specifications is ultimately settled. A fractional slot axial-flux permanent magnet (VPM) machine and an axial-flux surface VPM machine are designed to compare with the proposed configuration. Analysis results show that the TR-AFSAVPM machine has high power factor viz., 0.96 and high torque density viz., 24.2 kNm/m3. A prototype has been designed and tested to validate the results. No-load test result is illustrated in this paper and the rated load experiment will be added in the future.
Autors: Rui Zhang;Jian Li;Ronghai Qu;Dawei Li;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 244 - 253
Publisher: IEEE
 
» Analysis and Design of Zero-Current Switching Switched-Capacitor Cell Balancing Circuit for Series-Connected Battery/Supercapacitor
Abstract:
To overcome the problem that the balancing performance of existing switched-capacitor (SC) cell balancing systems drops along with the increase in the number of series-connected battery cells, a novel SC cell balancing circuit is presented in this paper. The same as other SC balancing systems, only a pair of complementary square-wave signals is required to control the proposed circuit. With resonant SC design, all switches employed in the proposed balancing circuit operate under zero-current switching. The equivalent model is derived to reveal the balancing performance of the proposed balancing circuit. The system feasibility and theoretical analysis are verified by both of simulation and experimental results.
Autors: Yuanmao Ye;Ka Wai Eric Cheng;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 948 - 955
Publisher: IEEE
 
» Analysis and Implementation of Closed-Loop Control of Electrolytic Capacitor-Less Six-Pulse DC-Link Bidirectional Three-Phase Grid-Tied Inverter
Abstract:
Cascaded bidirectional dc–ac converters are commonly used in uninterruptible power supply applications and battery chargers for electric vehicles. Power conversion units for such applications employ a large electrolytic capacitor at high-voltage dc bus, which not only reduces the lifetime but also adds to the weight of the converter. In this paper, a novel bidirectional dual active bridge cascaded three-phase converter (DABCC) with six-pulse dc link is proposed. Also, a new closed-loop control scheme to implement the six-pulse modulation (SPM) technique in DABCC is proposed. The advantages of the proposed control scheme in DABCC are that the electrolytic capacitor is eliminated and is replaced with a low-value film capacitor resulting in increased reliability, compactness, and reduced cost. SPM technique also increases the dc bus utilization and decreases the inverter average switching frequency to 33% when compared with the conventional sine pulse-width modulation (SPWM). Harmonic components introduced in the pole voltages of the SPM-modulated DABCC due to inverter dead time are analyzed, and a resonant controller is designed to mitigate them. Also, root mean square current stress for high-voltage dc-link capacitor is studied, and it is shown that the capacitor requirement for SPM modulation is lower than the conventional SPWM. To validate the proposed control scheme, an 800-W proof-of-concept laboratory hardware prototype is fabricated and experimental results are demonstrated.
Autors: V. K. Kanakesh;Dorai Babu Yelaverthi;Anirban Ghoshal;Akshay Kumar Rathore;Ranjit Mahanty;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 539 - 550
Publisher: IEEE
 
» Analysis and Modeling of Thermal-Electric Coupling Effect of High-Power Monolithically Integrated Light-Emitting Diode
Abstract:
A 2-D thermal-electric coupling model has been developed, which enables us to evaluate the current distribution of monolithically integrated light-emitting diode (MI-LED). Based on the experimental IR images, the current distributions have been evaluated for the MI-LEDs on two types’ heat sinks. For the MI-LED on poor thermal conductive chip-on-board heat sink, although there is a large junction temperature variation of 40 °C all over the chip, the current only varies from −16% to 11% due to the high parasitic series resistance and the topological design of MI-LED. The experiments show that the impact of the heat-crowding-induced uneven current distribution on the wall-plug efficiency is negligible at a power density of 1 W/mm2. The average junction temperature is still the dominant issue. With a high thermal conductive copper heat sink, the average junction temperature could be suppressed below 50 °C, and there is no obvious heat crowding and uneven current distribution observed.
Autors: Yibin Zhang;Mingdi Ding;Desheng Zhao;Hongjuan Huang;Longjie Huang;Yunzhen Lin;Difei Bian;Baoshun Zhang;Yong Cai;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 564 - 571
Publisher: IEEE
 
» Analysis of a Silicon Dual-Coupled-Ring Resonator Modulator Based on Push–Pull Coupling Tunings
Abstract:
We present a silicon dual-coupled-ring resonator modulator with push–pull coupling tunings. The basic idea of this scheme is to construct a dual-coupled-ring resonator structure in which the coupling coefficients of all coupling regions are tunable through Mach–Zehnder interferometers operated in push–pull modes. Two coupling coefficients are tuned jointly for optical bandwidth shaping and tuning while another coupling coefficient is tuned for high speed and chirp-free modulation. The fundamental analytical expressions for the intensity transmittance, the critical and the resonance conditions of the proposed dual-coupled-ring resonator modulator are derived. In addition, the performance simulations and optimization are presented and compared with those of the single-ring resonator modulator. The proposed dual-coupled-ring resonator modulator is more likely to achieve wide optical bandwidth tuning range and narrow channel spacing simultaneously, which are suitable for future optical processing and interconnects.
Autors: Zhen Zhou;Li Shuang Feng;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 12
Publisher: IEEE
 
» Analysis of Cross-Borehole Pulse Radar Signatures on a Terminated Tunnel With Various Penetration Lengths
Abstract:
A cross-borehole pulse radar system was operated to detect an intrusive man-made tunnel terminated just 1.2 m away from the line of sight between a newly drilled borehole pair at a tunnel test site. Unlike conventional radar signatures on a fully penetrated air-filled tunnel, the relatively fast arrival in the measured time-of-arrival (TOA) profile was highly suppressed at the depth of the terminated tunnel. To analyze the TOA contraction at a terminated tunnel without drilling additional borehole pairs, a finite-difference time-domain (FDTD) simulator is implemented using the accurately measured location information on the terminated tunnel and borehole pair. The relation curves between the time advance in the TOA profile and the penetration length of the terminated tunnel are plotted in the high and low limits of electrical properties of background rock. To verify the accuracy of our FDTD simulated results, the wideband complex permittivity profiles of the core rock samples’ boring at the tunnel test site are measured using an open-ended coaxial probe method. The calculated time advances agree well with the measured values in both cases of fully penetrated and closely terminated borehole pairs in the test site. The presented time advance curves for various penetration lengths will be a valuable guideline on detection of a terminated tunnel in site.
Autors: Jae-Hyoung Cho;Ji-Hyun Jung;Se-Yun Kim;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 799 - 807
Publisher: IEEE
 
» Analysis of Data Acquisition Time on Soil Moisture Retrieval From Multiangle L-Band Observations
Abstract:
This paper investigated the sensitivity of passive microwave L-band soil moisture (SM) retrieval from multiangle airborne brightness temperature data obtained under morning and afternoon conditions from the National Airborne Field Experiment conducted in southeast Australia in 2006. Ground measurements at a dryland focus farm including soil texture, soil temperature, and vegetation water content were used as ancillary data to drive the retrieval model. The derived SM was then in turn evaluated with the ground-measured near-surface SM patterns. The results of this paper show that the Soil Moisture and Ocean Salinity target accuracy of 0.04 for single-SM retrievals is achievable irrespective of the 6 A.M. and 6 P.M. overpass acquisition times for moisture conditions . Additional tests on the use of the air temperature as proxy for the vegetation temperature also showed no preference for the acquisition time. The performance of multiparameter retrievals of SM and an additional parameter proved to be satisfactory for SM modeling—independent of the acquisition time—with root-mean-square errors less than 0.06 for the focus farm.
Autors: Sandy Peischl;Jeffrey P. Walker;Dongryeol Ryu;Yann H. Kerr;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 966 - 971
Publisher: IEEE
 
» Analysis of DFT-Based Channel Estimation for Uplink Massive MIMO Systems
Abstract:
To reduce the edge effect in discrete Fourier transform-based channel estimation, various schemes have been proposed to estimate the channel response at the non-allocated subcarriers. However, it is not easy to estimate the channel response accurately at the non-allocated subcarriers, particularly at low signal-to-noise ratio (SNR). Moreover, the estimation places an additional computational burden on the receiver. The analysis in this letter shows that the edge effect is not serious in uplink massive multiple-input multiple-output systems. Zero padding at the non-allocated subcarriers is asymptotically optimal in the low SNR regime. We can also use fast Fourier transform/inverse fast Fourier transform pruning to reduce the computational complexity dramatically.
Autors: Hao Wu;Yuan Liu;Kai Wang;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 328 - 331
Publisher: IEEE
 
» Analysis of Electrothermal and Impact-Ionization Effects in Bipolar Cascode Amplifiers
Abstract:
This paper is aimed at the analysis of the influence of electrothermal and impact-ionization effects on the dc behavior of bipolar cascode amplifiers. A simple physics-based relationship is derived to predict the limit of the safe operating area in the output diagram. Experiments and circuit simulations are performed on amplifiers in GaAs and SiGe technologies to examine and explain the distortion in the dc – curves induced by these positive-feedback mechanisms, as well as to predict the temperatures of the individual devices.
Autors: Vincenzo d’Alessandro;Rosario D’Esposito;Andre G. Metzger;Kai H. Kwok;Klaus Aufinger;Thomas Zimmer;Niccolò Rinaldi;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 431 - 439
Publisher: IEEE
 
» Analysis of Energy Savings of CVR Including Refrigeration Loads in Distribution Systems
Abstract:
Conservation voltage reduction (CVR) plays an important role in energy savings and shaving peak demand. This paper quantifies energy savings for refrigeration loads (RLs) with experimentally validated air conditioner and refrigerator models. It is demonstrated that peak demand reduction and energy savings exist simultaneously during the implementation of CVR. A 1666-bus real meshed network with residential, small, and large commercial customers is simulated for the calculation of energy savings. Different working patterns: weekday and weekend; weather conditions: hottest and average summer days during peak load of the year; and load types: mixed load (ZIP and RLs) and ZIP load are studied. In addition, the IEEE 8500-node radial system with 100% residential customers is also used to show the energy savings of CVR. It is concluded that the economic benefits of CVR are larger for meshed networks than for radial systems. It is also shown experimentally and by simulation that CVR produces significant savings for both utilities and customers.
Autors: Jun Wang;Ashhar Raza;Tianqi Hong;Adriana Cisco Sullberg;Francisco de León;Qi Huang;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 158 - 168
Publisher: IEEE
 
» Analysis of Faults in Multiterminal HVDC Grid for Definition of Test Requirements of HVDC Circuit Breakers
Abstract:
This paper provides a detailed analysis of the temporal development of fault currents in a multiterminal high-voltage direct-current (MT-HVDC) grid composed of a bipolar converter configuration. The sequence of events following the occurrence of a pole-to-ground fault is identified, divided into three distinct periods; namely, submodule capacitor discharge, arm current decay, and ac in-feed periods. The critical parameters that have a significant impact on the fault current in each period are discussed. The impacts of various parameters of the HVDC grid such as the size of the current limiting reactor, ac grid strength, as well as the location of the fault within the grid are studied through PSCAD/EMTDC simulation. Then, a fault current interruption process using models of various HVDC circuit breaker technologies and the resulting stresses are studied. Both serve as important inputs to define test procedures. It is found that the HVDC circuit breakers are subjected to not only dc current and voltage stresses but also energy stress. These stresses are translated into test requirements.
Autors: Nadew Adisu Belda;Cornelis Arie Plet;Rene Peter Paul Smeets;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 403 - 411
Publisher: IEEE
 
» Analysis of Hexadecane Decomposition by Atmospheric Microplasma
Abstract:
Atmospheric microplasma has the potential to be one of the technologies used to purify indoor air. For example, plasma is used for pollutant decomposition or sterilization. In this study, we examined the removal of hexadecane by using microplasma. Hexadecane is contained in diesel oil and it is discharged to the air as exhaust gas. A decrease in the concentration of hexadecane from 3000 to 105 ppm was observed after 120 min of plasma processing. The removal energy efficiency of hexadecane was evaluated to 19.8 μg/W·h. Several by-products were obtained with the plasma process and were analyzed by detector tubes, Fourier transform infrared spectroscopy, and gas chromatograph–mass spectrometer. According to the analysis of the products, hexadecane was decomposed to alkane or alkene, which contains less carbon number 16, and finally, it was decomposed to CO. It became apparent that plasma can cut carbon bonds.
Autors: Kazuo Shimizu;Saho Muramatsu;Jaroslav Kristof;Marius Blajan;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 605 - 610
Publisher: IEEE
 
» Analysis of Magnetic Interaction in Remotely Controlled Magnetic Devices and its Application to a Capsule Robot for Drug Delivery
Abstract:
In this paper, we present the 3-D analysis of the torque transmitted to a small permanent magnet that is embedded in a capsule robot to achieve targeted drug delivery. This analysis is carried out by using analytical models and experimental results for the magnetic field created by multiple arc-shaped permanent magnets (ASMs), and the torque imparted to a magnetic capsule robot that has an arbitrary position and orientation. Our experimental results, which are in agreement with the analytical results, show that the on-board drug release mechanism can be actuated at any position and with large inclinations of the capsule robot without having to make positional adjustments in the external magnetic system. We have established analytical expressions describing the relationship between the rotating magnetic field created by the ASMs and the transmitted torque. Such relationships are essential to establish real-time control strategies for the actuation of magnetically articulated devices such as drug delivery in capsule robots.
Autors: Fredy Munoz;Gursel Alici;Hao Zhou;Weihua Li;Metin Sitti;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Feb 2018, volume: 23, issue:1, pages: 298 - 310
Publisher: IEEE
 
» Analysis of Millimeter-Wave Multi-Hop Networks With Full-Duplex Buffered Relays
Abstract:
The abundance of spectrum in the millimeter-wave (mm-wave) bands makes it an attractive alternative for future wireless communication systems. Such systems are expected to provide data transmission rates in the order of multi-gigabits per second in order to satisfy the ever-increasing demand for high rate data communication. Unfortunately, mm-wave radio is subject to severe path loss, which limits its usability for long-range outdoor communication. In this paper, we propose a multi-hop mm-wave wireless network for outdoor communication, where multiple full-duplex buffered relays are used to extend the communication range, while providing end-to-end performance guarantees to the traffic traversing the network. We provide a cumulative service process characterization for the mm-wave propagation channel with self-interference in terms of the moment generating function of its channel capacity. Then, we then use this characterization to compute probabilistic upper bounds on the overall network performance, i.e., total backlog and end-to-end delay. Furthermore, we study the effect of self-interference on the network performance and propose an optimal power allocation scheme to mitigate its impact in order to enhance network performance. Finally, we investigate the relation between relay density and network performance under a sum power constraint. We show that increasing relay density may have adverse effects on network performance, unless the self-interference can be kept sufficiently small.
Autors: Guang Yang;Ming Xiao;Hussein Al-Zubaidy;Yongming Huang;James Gross;
Appeared in: IEEE/ACM Transactions on Networking
Publication date: Feb 2018, volume: 26, issue:1, pages: 576 - 590
Publisher: IEEE
 
» Analysis of Power System Oscillations From PMU Data Using an EPLL-Based Approach
Abstract:
Recently, the application of the adaptive notch filter (ANF) concept to the analysis of damped oscillations and the estimation of frequency and damping factor of such oscillations was introduced. This paper presents the application of the enhanced phase-locked loop (EPLL) to the same problem. A modified version of the EPLL is developed that includes the estimation of damping factor in addition to the already estimated variables of amplitude, phase angle, and frequency. The structure, mathematical formulation, and theoretical stability analysis of the proposed method, including guidelines for its parameter tuning, are presented. Simulation results verify the analytical derivations and the desirable performance of the proposed method. This paper concludes that the EPLL-based approach can address the problem as efficient as the ANF approach while offering more robust and accurate results at low sampling rate applications.
Autors: Hossein Zamani;Masoud Karimi-Ghartemani;Mohsen Mojiri;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Feb 2018, volume: 67, issue:2, pages: 307 - 316
Publisher: IEEE
 
» Analysis of Ranging Precision in an FMCW Radar Measurement Using a Phase-Locked Loop
Abstract:
The standard deviation in a frequency modulated continuous wave radar distance measurement using a charge pump phase-locked loop (PLL) is calculated analytically. The phase noise of the PLL is modeled as an Ornstein–Uhlenbeck process resulting in a Lorentzian spectrum. We calculate the distance error as a function of the receiver noise bandwidth and the target distance. Depending on the frequency estimation algorithm and the target distance, the rms distance error due to PLL phase noise increases by about 6–9 dB with doubling the target distance. By contrast, the white noise in the radar receiver raises the distance error by about 12 dB in the far field with distance doubling, making this error contribution dominant for large target distances. These findings are verified by measurements on a scalable 61/122-GHz radar sensor platform.
Autors: Frank Herzel;Dietmar Kissinger;Herman Jalli Ng;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 783 - 792
Publisher: IEEE
 
» Analysis of Short-Circuit Current Characteristics and Its Distribution of Artificial Grounding Faults on DC Transmission Lines
Abstract:
Grounding faults are common faults on dc transmission lines. Characteristics of the short-circuit current, such as amplitude and frequency, and its following distribution are very important for analyzing the influence of the fault. Based on the ±500 kV Yongfu dc transmission project in China, several artificial grounding short-circuit tests at the terminal or middle of the dc transmission line were carried out. This paper reports the measurement and analysis of the short-circuit current and its distribution in a dc system for the first time. The short-circuit current distribution includes currents in the ground wires of the fault tower and currents in ground wires, which are connected to the converter station grounding grid, such as the optical ground wire (OPGW) currents of ac outgoing lines, neutral point currents of different transformers, and the grounding electrode bus arrester current. In addition, the frequency components of the fault currents are analyzed. Based on the PSCAD/EMTDC software, the current distribution is simulated and discussed. The simulation results are in good agreement with the test results.
Autors: Caowei Huang;Bo Zhang;Yutang Ma;Fangrong Zhou;Jinliang He;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 520 - 528
Publisher: IEEE
 
» Analysis on Location Accuracy for the Binocular Stereo Vision System
Abstract:
Binocular stereo vision (BSV) system has been widely used in various fields, such as intelligent manufacture, smart robot, and so on. However, the location accuracy of the current BSV still cannot fully satisfy industry requirements due to lack of a parameters optimization BSV system. In this paper, a high accuracy BSV system is proposed. This is achieved through analyzing the seven parameters of the BSV system, which are classified into two groups: system structure parameters (SSPs) and camera calibration parameters (CCPs). For the SSPs, an improved analysis model is designed to expose the possible errors caused by three parameters. Furthermore, a new correlation model among them is also proposed to analyze the errors caused by their correlation. On the other hand, for the CCPs, the orthogonal experiment model is employed for selecting the optimal combination of the four calibration parameters. Meanwhile, the weight among the four parameters is also analyzed for reducing errors. Finally, the effectiveness of our proposed method is demonstrated by a large number of experiments. It gives a useful reference to the BSV system used in applied optics research and application fields.
Autors: Lu Yang;Baoqing Wang;Ronghui Zhang;Haibo Zhou;Rongben Wang;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 16
Publisher: IEEE
 
» Analysis, Design, and Implementation of Passivity-Based Control for Multilevel Railway Power Conditioner
Abstract:
In recent years, railway power conditioner (RPC) has been used to improve the power quality of a traction power system. In engineering application of RPC, mismatches between parameters used in controller and actual values are inevitable, which will increase the difficulty of current controller design and deteriorate compensation performance. In this paper, a passivity-based control (PBC) system is studied for multilevel RPC to enhance its tolerance for mismatches. According to the topology of multilevel RPC, equivalent electrical and mathematical models are developed. To employ PBC, Euler–Lagrange system model of RPC is established by Park (αβ/dq) transformation, and the passivity of RPC and stability of PBC are proved. On this basis, the robustness of PBC is analyzed and criteria for damping selection are derived. Finally, simulation and experiments have been carried out to verify the structure and control method in the paper.
Autors: Jun Min;Fujun Ma;Qianming Xu;Zhixing He;An Luo;Alfio Spina;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Feb 2018, volume: 14, issue:2, pages: 415 - 425
Publisher: IEEE
 
» Analytic Evaluation of Fine Alignment for Velocity Aided INS
Abstract:
Coarse attitude initialization procedure is used to determine the initial attitude of the inertial navigation system. To improve the accuracy of the attitude to a desired value, fine alignment (FA) process is employed. In stationary conditions, zero velocity updates are usually used to achieve such goal. In this paper, an analytic evaluation of the steady-state properties of the FA process is presented. The contribution of this paper is twofold: 1) closed-form analytic solutions to the error-state covariance of the FA process are derived and 2) semianalytic solutions to the convergence time of the error-state covariance are shown. With such closed-form solutions at hand, insight can be gained into the parameters involved in the FA process in preliminary design process. Simulation and field experiments are given to support the analytical expressions.
Autors: Alexander Tsukerman;Itzik Klein;
Appeared in: IEEE Transactions on Aerospace and Electronic Systems
Publication date: Feb 2018, volume: 54, issue:1, pages: 376 - 384
Publisher: IEEE
 
» Analytical Algorithm for 3-D Localization of a Single Source With Uniform Circular Array
Abstract:
This letter presents an analytical algorithm for estimating three-dimensional (3-D) localization of a single source with uniform circular arrays (UCAs). Fourier transforms are exploited to expand the phase distribution of a single source, and the localization problem is reformulated as an equivalent spectrum manipulation problem. 3-D parameters are decoupled to different spectrums in the Fourier domain. Algebraic relations are established between 3-D parameters and Fourier spectrums. Fourier sampling theorem ensures that the minimum element number for 3-D localization with a UCA is five. Accuracy analysis provides mathematical insights into the function of a center sensor. Numerical simulations and experimental results verify the effectiveness and appealing performance of the proposed 3-D localization algorithm.
Autors: Le Zuo;Jin Pan;Zhongxiang Shen;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 323 - 326
Publisher: IEEE
 
» Analytical Derivation of the AC-Side Input Admittance of a Modular Multilevel Converter With Open- and Closed-Loop Control Strategies
Abstract:
This paper deals with the derivation of the ac-side input admittance of a grid-connected modular multilevel converter (MMC) under both open- and closed-loop ac-side current control strategies. The contribution of the internal dynamics of the MMC on the input admittance depends on the type of ac-side controllers implemented. For this reason, the input admittance is first derived with the MMC operating in open loop on the ac side. The results are then modified to include various ac-side controllers in order to analyze the impact of the internal dynamics of the MMC on the total input admittance. Based on the findings, recommendations are given on modeling the input admittance of the MMC. Finally, the derived analytical models are verified using a detailed switching model of the MMC in the frequency domain.
Autors: Mebtu Beza;Massimo Bongiorno;Georgios Stamatiou;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 248 - 256
Publisher: IEEE
 
» Analytical Formulas for Mean Gain and Excess Noise Factor in InAs Avalanche Photodiodes
Abstract:
It has been known that McIntyre’s local multiplication theory for avalanche photodiodes (APDs) does not fully explain the experimental results for single-carrier InAs APDs, which exhibit excess noise factor values below 2. While it has been established that the inclusion of the dead-space effect in the nonlocal multiplication theory resolves this discrepancy, no closed-form formulas for the mean gain and excess noise factor have been specialized to InAs APDs in a nonlocal setting. Upon utilizing prior analytical formulation of single-carrier avalanche multiplication based on age-dependent branching theory in conjunction with nonlocal ionization coefficients and thresholds for InAs, closed-form solutions of the mean gain and the excess noise factor for InAs APDs are provided here for the first time. The formulas are validated against published experimental data from InAs APDs across a variety of multiplication region widths and are shown to be applicable for devices with multiplication widths of 500 nm and larger.
Autors: Erum Jamil;Majeed M. Hayat;Gordon A Keeler;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 610 - 614
Publisher: IEEE
 
» Analyzing Home Automation and Networking Technologies
Abstract:
Due to the rapid advancements in networking and automation technologies, the concept of smart homes has started taking shape. AT&T Digital Life, Schneider's Wiser homes, and Qualcomm's M2M communication, among others, are examples of ventures by conglomerates into the business of home automation. Three-quarters of homes in the United States possess computers, and more than two-thirds of those are connected to the Internet. Wireless networking in the form of Wi-Fi is present in 17% of homes.
Autors: Eshan Shailendra;Praneet Kaur Bhatia;
Appeared in: IEEE Potentials
Publication date: Feb 2018, volume: 37, issue:1, pages: 27 - 33
Publisher: IEEE
 
» Anatomically Constrained Neural Networks (ACNNs): Application to Cardiac Image Enhancement and Segmentation
Abstract:
Incorporation of prior knowledge about organ shape and location is key to improve performance of image analysis approaches. In particular, priors can be useful in cases where images are corrupted and contain artefacts due to limitations in image acquisition. The highly constrained nature of anatomical objects can be well captured with learning-based techniques. However, in most recent and promising techniques such as CNN-based segmentation it is not obvious how to incorporate such prior knowledge. State-of-the-art methods operate as pixel-wise classifiers where the training objectives do not incorporate the structure and inter-dependencies of the output. To overcome this limitation, we propose a generic training strategy that incorporates anatomical prior knowledge into CNNs through a new regularisation model, which is trained end-to-end. The new framework encourages models to follow the global anatomical properties of the underlying anatomy (e.g. shape, label structure) via learnt non-linear representations of the shape. We show that the proposed approach can be easily adapted to different analysis tasks (e.g. image enhancement, segmentation) and improve the prediction accuracy of the state-of-the-art models. The applicability of our approach is shown on multi-modal cardiac data sets and public benchmarks. In addition, we demonstrate how the learnt deep models of 3-D shapes can be interpreted and used as biomarkers for classification of cardiac pathologies.
Autors: Ozan Oktay;Enzo Ferrante;Konstantinos Kamnitsas;Mattias Heinrich;Wenjia Bai;Jose Caballero;Stuart A. Cook;Antonio de Marvao;Timothy Dawes;Declan P. O‘Regan;Bernhard Kainz;Ben Glocker;Daniel Rueckert;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Feb 2018, volume: 37, issue:2, pages: 384 - 395
Publisher: IEEE
 
» Angle Estimation With Polarization Filtering: A Single Snapshot Approach
Abstract:
When a monopulse radar is subjected to main-lobe barrage interference, the target and the interference source are both located within the 3 dB beamwidth of the radar; the target returns are subsumed by the interference, which results in incorrect detection, erroneous angle measurements, and tracking error. Based on a hybrid polarimetric monopulse radar with six channels, a new approach is presented for estimating the target angle from a single snapshot in the presence of main-lobe barrage interference. By means of polarization filtering and polarization synthesis of signals from multiple channels with two orthogonal polarizations, a new pair of sum and difference signals is formed that represents the angle difference between the target and the interference source. After standard monopulse processing of these new signals and additional compensation, the estimate of the target angle is derived with low computational complexity.
Autors: Jiazhi Ma;Longfei Shi;Yongzhen Li;Shunping Xiao;Xuesong Wang;
Appeared in: IEEE Transactions on Aerospace and Electronic Systems
Publication date: Feb 2018, volume: 54, issue:1, pages: 257 - 268
Publisher: IEEE
 
» Angular Momentum-Dependent Transmission of Circularly Polarized Vortex Beams Through a Plasmonic Coaxial Nanoring
Abstract:
In this paper, we report on the theoretical and numerical study of the transmission of circularly polarized vortex beams through a plasmonic coaxial nanoring. We show that the transmission peak wavelength of an incident circularly polarized vortex beam is dominantly governed by the total angular momentum, which determines the coupling to the plasmonic eigenmode supported by the coaxial nanoring with a given geometry and ultimately the transmitted beam in the far field. In addition, our study shows that the total angular momentum of the incident circularly polarized vortex beam can be conserved, where the far field of the transmitted beam contains both left- and right-handed circular polarization components with correspondingly modulated orbital angular momentum preserving the same total angular momentum. Our work can be potentially useful to advanced nanophotonic devices harnessing light's angular momentum division.
Autors: Shuai Wang;Zi-Lan Deng;Yaoyu Cao;Dejiao Hu;Yi Xu;Boyuan Cai;Long Jin;Yuan Bao;Xiaolei Wang;Xiangping Li;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 9
Publisher: IEEE
 
» Angular-Dependent Radius Measurements at Rotating Objects Using Underdetermined Sensor Systems
Abstract:
Precise and contactless shape measurements of rotating objects is important, e.g., for monitoring and controlling the manufacturing quality in lathes. For this purpose, multisensor and single-sensor approaches based on optical distance and surface velocity measurements are state-of-the-art techniques. Two- and single-sensor systems are particularly promising to measure the angular-dependent radius of the cross section of the rotating object in a scanning regime with minimal optical access. Since a comparison between the different sensor systems is missing, the potential of these underdetermined sensor systems is unclear. In addition, displacements of the rotational axis and sensor misalignments are suspected to be crucial error sources, but the error is unknown. For this reason, an error analysis is performed regarding the resulting systematic error and the random error for the two- and single-sensor systems. As a result, the different sensor systems have an equal cross-sensitivity with respect to lateral displacements of the rotational axis from the sensor axes, but the two-sensor approach has the lowest sensitivity regarding sensor misalignments. For the studied measurement conditions, the systematic error dominates the sensor noise for the two-sensor system and the single-sensor system with combined distance and velocity measurement at an object mean radius >6 mm. The smallest total measurement uncertainty is obtained with the two-sensor system. Finally, the relevance of systematic error depends on the utilization, i.e., for instance on the absolute rotor radius, the stability of the rotor axis, the sensor position, the accuracy of the sensor alignment, and the uncertainty of the distance and/or velocity measurements.
Autors: Andreas Fischer;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Feb 2018, volume: 67, issue:2, pages: 425 - 430
Publisher: IEEE
 
» Angularly Stable Frequency Selective Surface Combined With a Wide-Scan Phased Array
Abstract:
A five-layer frequency selective surface (FSS) composed of subwavelength elements with large harmonic rejection bandwidth is presented. The FSS design is based on an equivalent circuit model, where the interlayer interaction is only described with a single transmission line representing the fundamental Floquet wave. A prototype of the designed FSS is fabricated, and the measured response exhibits good stability over a wide conical incidence range up to 45°. The FSS is combined with a wide-scanning connected array of dipoles to implement a phased array with integrated filtering properties. A dispersion analysis is performed to define the distance between the array and the FSS that avoids the propagation of surface waves between the combined structures, allowing to maximize the radiation efficiency. The performance of the array combined with the FSS is experimentally characterized, showing high-order harmonic rejection better than 17 dB over a large bandwidth.
Autors: Cristina Yepes;Daniele Cavallo;Erio Gandini;Stefania Monni;Andrea Neto;Frank E. van Vliet;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 1046 - 1051
Publisher: IEEE
 
» Anisotropic Reverse-Time Migration of Ground-Penetrating Radar Data Collected on the Sand Dunes in the Badain Jaran Desert
Abstract:
Ground-penetrating radar (GPR) profiling is the primary tool to provide detail information of the internal structure and characteristics inside a sand dune in the desert area. However, with the severe elevation change in a short horizontal distance and on the rugged and complex surface topography of the sand dunes, getting clear imaging of the internal structure of sand dunes from the GPR profiling is still a big challenge. The classic imaging technique such as the Kirchhoff migration has been applied to process GPR data on sand dunes, with limited success. The reverse-time migration (RTM) technique is the most advanced imaging technique that can handles GPR data acquired on rugged surface with severe topographic relief to generate subsurface structural images with high fidelity and has been tried to process GPR data on sand dunes. The results are encouraging, and the imaging quality is significantly improved. The finite-difference time-domain (FDTD) method is the major numerical tool for forward and backward continuations of the wave field during the RTM process. There are two aspects for using FDTD in RTM of GPR data on sand dunes still need improvement: the numerical scattering caused by the staircase approximation of the ground surface by using gridding in the Cartesian coordinate, and the negligence of the possible anisotropy of the electromagnetic material properties due to the calcareous cementation bedding inside a sand dune. In this paper, we develop the RTM algorithm based on the staggered grid FDTD that handles the rugged topographic surface by using the curvilinear coordinate, and the possible anisotropic radar wave velocity of the sand dune media. We first demonstrate the equivalency of the nonuniform, isotropic medium and the uniform, anisotropic medium for justifying using the uniform, anisotropic velocity in the RTM by synthetic modeling. Next, we validate our approach of using the synthetic data with the comparison of using the Cartesian coordinate- and the curvilinear coordinate in an isotropic medium. The results indicate that the RTM algorithm using the curvilinear coordinate can efficiently eliminate the adverse effect of the staircase approximated boundary of the topography surface. Finally, we processed the real GPR data collected on a sand dune in the Badain Jaran desert by using the curvilinear coordinate and the uniform, anisotropic velocity in FDTD forward and backward wave field continuation. Comparison of the results indicates that the RTM imaging using the boundary-conforming curvilinear coordinate and anisotropic velocity gains more coherent and higher resolution images for the calcareous cementation layers and the water table.
Autors: Xinglin Lu;Ao Song;Rongyi Qian;Lanbo Liu;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Feb 2018, volume: 11, issue:2, pages: 647 - 654
Publisher: IEEE
 
» Anomaly Detection and Array Diagnosis in Wireless Networks with Multiple Antennas: Framework, Challenges and Tools
Abstract:
Anomaly detection and array diagnosis in wireless networks are both important technologies and have many applications ranging from discovering malicious traffic and identifying abnormal nodes, to detecting faulty antennas and so on. In general, anomaly detection mainly depends on relational data, which denotes the links between nodes of the networks, to decide whether abnormal networks caused by intentional attack or array failure are embedded in large wireless networks. Additionally, the typical scheme of array diagnosis is to measure signals radiating from the array antennas under test to detect the faulty elements by using a centralized method. However, in largescale wireless networks, a centralized strategy results in a communication bottleneck because of transmitting all signals to a center node. Moreover, since faulty elements are only a tiny proportion for the whole networks, the method that all antennas are under test is unnecessary and also causes huge computational complexity to identify the failure of elements. Aiming to mitigate these problems, this article provides a novel framework to monitor networks and detect faulty antennas by fusing relational data and measured signals. In this article, we first review the algorithms related to anomaly detection and survey the array diagnosis problem. In particular, we discuss the relationship between anomaly detection and array diagnosis in the new framework and highlight the importance of data fusion. Finally, the main challenges are presented and mathematical tools are introduced to solve the corresponding problems.
Autors: Bo Wang;Fengye Hu;Yanping Zhao;Terry N. Guo;
Appeared in: IEEE Network
Publication date: Feb 2018, volume: 32, issue:1, pages: 152 - 159
Publisher: IEEE
 
» Anomaly Detection and Attribution in Networks With Temporally Correlated Traffic
Abstract:
Anomaly detection in communication networks is the first step in the challenging task of securing a network, as anomalies may indicate suspicious behaviors, attacks, network malfunctions, or failures. In this paper, we address the problem of not only detecting the anomalous events but also of attributing the anomaly to the flows causing it. To this end, we develop a new statistical decision theoretic framework for temporally correlated traffic in networks via Markov chain modeling. We first formulate the optimal anomaly detection problem via the generalized likelihood ratio test (GLRT) for our composite model. This results in a combinatorial optimization problem which is prohibitively expensive. We then develop two low-complexity anomaly detection algorithms. The first is based on the cross entropy (CE) method, which detects anomalies as well as attributes anomalies to flows. The second algorithm performs anomaly detection via GLRT on the aggregated flows transformation—a compact low-dimensional representation of the raw traffic flows. The two algorithms complement each other and allow the network operator to first activate the flow aggregation algorithm in order to quickly detect anomalies in the system. Once an anomaly has been detected, the operator can further investigate which specific flows are anomalous by running the CE-based algorithm. We perform extensive performance evaluations and experiment our algorithms on synthetic and semi-synthetic data, as well as on real Internet traffic data obtained from the MAWI archive, and finally make recommendations regarding their usability.
Autors: Ido Nevat;Dinil Mon Divakaran;Sai Ganesh Nagarajan;Pengfei Zhang;Le Su;Li Ling Ko;Vrizlynn L. L. Thing;
Appeared in: IEEE/ACM Transactions on Networking
Publication date: Feb 2018, volume: 26, issue:1, pages: 131 - 144
Publisher: IEEE
 
» Anonymity Leakage in Private VoIP Networks
Abstract:
Private communication detection (PCD) is a traffic-analysis technique whereby an ordinary user of a communication network exploits side channels in end-point devices to observe the busy/idle activity status of targeted users. Correlations of users’ activity status allows collection of communication records that reveal private relationships. PCD techniques have been demonstrated for a number of communication technologies, such as Wi-Fi and VoIP, and their effectiveness shown even when the communication network is private; i.e., it provides content confidentiality, flow anonymity, and user pseudonymity. In this paper, we present a mathematical model of PCD that captures the activity status of two targets in a private VoIP network, including the probing process of an attacker that aims to breach their communication anonymity. Using this model, we a) develop fundamental bounds on PCD accuracy; b) measure the anonymity leakage in terms of the amount of call record information obtained in an attack; and c) provide performance guarantees and compare the efficacy of different PCD countermeasures, such as resource randomization and use of firewalls.
Autors: Saurabh Shintre;Virgil Gligor;Jo ao Barros;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Feb 2018, volume: 15, issue:1, pages: 14 - 26
Publisher: IEEE
 
» Antenna Miniaturization Techniques: A Review of Topology- and Material-Based Methods
Abstract:
Antenna miniaturization has been the subject of numerous studies for almost 70 years [1]-[4]. Early studies showed that a decrease in the size of an antenna results in a direct reduction in its bandwidth and efficiency (hr) [1], [2]. The size limitation translates into a lower boundary on the achievable radiation quality factor (Q factor) and consequently on the maximum achievable impedance bandwidth. Recently, many new investigations have been conducted to reduce the form factor (or the overall size) of different types of antennas while trying to maintain acceptable matching properties and operating bandwidth. These miniaturization techniques are generally related to changing the electrical and physical properties of an antenna.
Autors: Mojtaba Fallahpour;Reza Zoughi;
Appeared in: IEEE Antennas and Propagation Magazine
Publication date: Feb 2018, volume: 60, issue:1, pages: 38 - 50
Publisher: IEEE
 
» Antenna System Composed of T-Shaped Elements Coupled to an Open Radial Waveguide
Abstract:
An antenna system composed of an activated open radial waveguide (RadWG) and parasitic T-shaped elements is proposed as a high-gain antenna, where the radiation beam is steerable around the system axis. The T-shaped elements are proximity-coupled to the RadWG. It is found that the upper round plate for the RadWG contributes to forming a desirable beam and increasing the gain. The beam steering with a gain of greater than targeted 9 dBi in 16 azimuthal directions is obtained by changing the location of open-state T-shaped elements whose height is 0.18 wavelength. Effects on the radiation characteristics of the system parameters, including the RadWG height, upper round plate diameter, ground plane diameter, and number of open-state T-shaped elements, are also analyzed and discussed.
Autors: Hisamatsu Nakano;Yuhei Kameta;Toru Kawano;Amit Mehta;Arpan Pal;Andrew Skippins;Junji Yamauchi;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 550 - 563
Publisher: IEEE
 
» Antennas for Autonomy [Editor's Comments]
Abstract:
Autors: Mahta Moghaddam;
Appeared in: IEEE Antennas and Propagation Magazine
Publication date: Feb 2018, volume: 60, issue:1, pages: 4 - 4
Publisher: IEEE
 
» AntMapper: An Ant Colony-Based Map Matching Approach for Trajectory-Based Applications
Abstract:
Many trajectory-based applications require an essential step of mapping raw GPS trajectories onto the digital road network accurately. This task, commonly referred to as map matching, is challenging due to the measurement error of GPS devices in critical environment and the sampling error caused by long sampling intervals. Traditional algorithms focus on either a local or a global perspective to deal with the problem. To further improve the performance, this paper develops a novel map matching model that considers local geometric/topological information and a global similarity measure simultaneously. To accomplish the optimization goal in this complex model, we adopt an ant colony optimization algorithm that mimics the path finding process of ants transporting food in nature. The algorithm utilizes both local heuristic and global fitness to search the global optimum of the model. Experimental results verify that the proposed algorithm is able to provide accurate map matching results within a relatively short execution time.
Autors: Yue-Jiao Gong;En Chen;Xinglin Zhang;Lionel M. Ni;Jun Zhang;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Feb 2018, volume: 19, issue:2, pages: 390 - 401
Publisher: IEEE
 
» Application of Acoustoelasticity to Evaluate Nonlinear Modulus in Ex Vivo Kidneys
Abstract:
Currently, dynamic elastography techniques estimate the linear elastic shear modulus of different body tissues. New methods that investigate other properties of soft tissues such as anisotropy, viscosity, and shear nonlinearity would provide more information about the structure and function of the tissue and might provide a better contrast than tissue stiffness and hence provide more effective diagnostic tools for some diseases. It has previously been shown that shear wave velocity in a medium changes due to an applied stress, a phenomenon called acoustoelasticity (AE). Applying a stress to compress a medium while measuring the shear wave velocity versus strain provides data with which the third-order nonlinear shear modulus can be estimated. To evaluate the feasibility of estimating , we evaluated ten ex vivo porcine kidneys embedded in 10% porcine gelatin to mimic the case of a transplanted kidney. Under assumptions of an elastic incompressible medium for AE measurements, the shear modulus was quantified at each compression level and the applied strain was assessed by measuring the change in the thickness of the kidney cortex. Finally, was calculated by applying the AE theory. Our results demonstrated that it is possible to estimate a nonlinear shear modulus by monitoring the changes in strain and due to kidney deformation. The magnitudes of are higher when the compression is performed progressively and when using a plate attached to the transducer. Nevertheless, the values obtained for $A$ <- inline-formula> are similar to those previously reported in the literature for breast tissue.
Autors: Sara Aristizabal;Carolina Amador Carrascal;Ivan Z. Nenadic;James F. Greenleaf;Matthew W. Urban;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Feb 2018, volume: 65, issue:2, pages: 188 - 200
Publisher: IEEE
 
» Application of Genetic Programming (GP) Formalism for Building Disease Predictive Models from Protein-Protein Interactions (PPI) Data
Abstract:
Protein-protein interactions (PPIs) play a vital role in the biological processes involved in the cell functions and disease pathways. The experimental methods known to predict PPIs require tremendous efforts and the results are often hindered by the presence of a large number of false positives. Herein, we demonstrate the use of a new Genetic Programming (GP) based Symbolic Regression (SR) approach for predicting PPIs related to a disease. In this case study, a dataset consisting of 135 PPI complexes related to cancer was used to construct a generic PPI predicting model with good PPI prediction accuracy and generalization ability. A high correlation coefficient (CC) magnitude of 0.893, and low root mean square error (RMSE), and mean absolute percentage error (MAPE) values of 478.221 and 0.239, respectively, were achieved for both the training and test set outputs. To validate the discriminatory nature of the model, it was applied on a dataset of diabetes complexes where it yielded significantly low CC values. Thus, the GP model developed here serves a dual purpose: (a) a predictor of the binding energy of cancer related PPI complexes, and (b) a classifier for discriminating PPI complexes related to cancer from those of other diseases.
Autors: Renu Vyas;Sanket Bapat;Purva Goel;Muthukumarasamy Karthikeyan;Sanjeev S. Tambe;Bhaskar D. Kulkarni;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Feb 2018, volume: 15, issue:1, pages: 27 - 37
Publisher: IEEE
 
» Application of Predictor Feedback to Compensate Time Delays in Connected Cruise Control
Abstract:
In this paper, we investigate a vehicular string traveling on a single lane, where vehicles use connected cruise control to regulate their longitudinal motion based on data received from other vehicles via wireless vehicle-to-vehicle communication. Assuming digital controllers, the sample-and-hold units introduce time-periodic time delays in the control loops and the delays increase when data packets are lost. We investigate the effect of packet losses on plant and string stability while varying the control gains and determine the minimum achievable time gap below which stability cannot be achieved. We propose two predictor feedback control strategies that overcome the destabilizing effect of the time delay caused by the sample-and-hold unit and packet losses.
Autors: Tamás G. Molnár;Wubing B. Qin;Tamás Insperger;Gábor Orosz;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Feb 2018, volume: 19, issue:2, pages: 545 - 559
Publisher: IEEE
 
» Application of Updated Landau–Lifshitz–Bloch Equations to Heat-Assisted Magnetic Recording
Abstract:
Previously, we applied analysis of macro-spin magnetization dynamics described by the Landau–Lifshitz–Bloch (LLB) equation to issues in the future magnetic recording which combined heat-assisted magnetic recording (HAMR) with bit-patterned media (BPM). In this paper, we use updated versions of the LLB equation to revisit the magnetic switching reliability as an HAMR head is passed over a single, isolated grain of a bit-patterned medium. Areal density was varied, while the packing density of the BPM was set to 0.4 or 0.5. LLB writing reliability is also assessed with the Arrhenius–Nèel theory that has been upgraded with recent work related to the Stoner–Wohlfarth model to add understanding of the role of thermodynamics in thermomagnetic recording and the long-time stability of magnetic reversal.
Autors: Terry W. McDaniel;
Appeared in: IEEE Transactions on Magnetics
Publication date: Feb 2018, volume: 54, issue:2, pages: 1 - 11
Publisher: IEEE
 
» Applying Metamaterial-Based Repeater in LC Passive Wireless Sensors to Enhance Readout
Abstract:
Inductor–capacitor (LC) passive wireless sensors allow for a continuous, real-time monitoring for various parameters of interest in situations, where wired connections are difficult or even impossible. However, geometrical constraints reduce the magnetic coupling between the sensor and the readout coil, resulting in a limited interrogation distance. Here, we propose a left-handed metamaterial as a repeater to enhance the readout of the LC passive wireless sensors. The left-handed metamaterial consists of double-side square spirals and possesses negative relative permeability. The operating frequency of the left-metamaterial is designed adjustable to cover the frequency spectrum of the sensor. By monitoring the relative humidity as an example, we have demonstrated that the readout distance with the left-handed metamaterial can achieve nearly 1.8 times as long as that without metamaterial, while keeping their signal strength and sensitivity the same. Overall, this strategy through the metamaterials-based repeaters represents an effective approach for enhancing the readout.
Autors: Lei Dong;Li-Feng Wang;Qing-An Huang;
Appeared in: IEEE Sensors Journal
Publication date: Feb 2018, volume: 18, issue:4, pages: 1755 - 1760
Publisher: IEEE
 
» Applying Software Engineering Standards in Very Small Entities: From Startups to Grownups
Abstract:
Very small entities (VSEs) are organizations with up to 25 people. The ISO/IEC 29110 series of standards and guides target VSEs with little or no experience or expertise in selecting the appropriate processes from lifecycle standards and tailoring them to a project’s needs. This article gives an overview of ISO/IEC 29110, some examples of VSEs that have implemented it, and those implementations’ results.
Autors: Claude Y. Laporte;Mirna Munoz;Jezreel Mejia Miranda;Rory V. O’Connor;
Appeared in: IEEE Software
Publication date: Feb 2018, volume: 35, issue:1, pages: 99 - 103
Publisher: IEEE
 
» Approximate and Sublinear Spatial Queries for Large-Scale Vehicle Networks
Abstract:
With advances in vehicle-to-vehicle communication, future vehicles will have access to a communication channel through which messages can be sent and received when two get close to each other. This enabling technology makes it possible for authenticated users to send queries to those vehicles of interest, such as those that are located within a geographic region, over multiple hops for various application goals, such as ride sharing, interest query, among others. However, naive methods for spatial queries usually require sending the queries to each active vehicle in a region through flooding methods, which will incur communication overhead proportional to the density of vehicles. In this paper, we study the problem of spatial queries for vehicle networks by investigating probabilistic approaches, where we only try to obtain approximate estimates within desired error bounds using sublinear overheads. We demonstrate that by making this relaxation, we can develop approximate query methods for spatial-temporal application requirements such that their overhead is considerably lower than conventional methods. Our key contributions include a random-walk forest based query dissemination method and a topology-aware estimation aggregation method for better algorithm convergence time and estimation accuracy. We use simulated real-world traces to test the proposed methods, and our experimental results show that our proposed method can indeed provide desired estimation accuracy with a high efficiency.
Autors: Lipeng Wan;Zhibo Wang;Zheng Lu;Yunhe Feng;Hairong Qi;Wenjun Zhou;Qing Cao;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1561 - 1569
Publisher: IEEE
 
» Approximate Relations of Admittance for Symmetrically Arranged Dipoles
Abstract:
We previously proposed an approximate relation between admittance and , where is the admittance of a set of dipoles whose ports are located at their centers and is the admittance of the same set of dipoles with one is removed. Based on the relation, approximate expressions of were derived for the case that dipoles are symmetrically arranged. Their validity is examined by simulations and experiments in this communication.
Autors: Kyoichi Iigusa;Hirokazu Sawada;Fumihide Kojima;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 984 - 989
Publisher: IEEE
 
» ARC Flash KPI Compliance at a Large Oil and Gas Company
Abstract:
An oil and gas company's arc flash electrical safe operations program is a corporate initiative to prevent electrical arc flash injuries. The program implements the company general instruction—electrical arc flash hazard mitigation, which provides minimum safe work requirements for protection of personnel in the workplace against electrical arc flash hazards in accordance with the National Fire Protection Agency 70E. The program tracks five key performance indicators (KPIs) to protect employees from arc flash hazards in all company facilities, which are as follows: 1) technology deployment; 2) training and certification; 3) operation and maintenance delineation; 4) operation and maintenance unified procedures; and 5) arc flash analysis. To verify compliance, the company initiated field-based assessments conducted by a specialized team of Power Systems Compliance and Electrical Engineers. The assessments are designed to validate each facility's compliance as well as to identify any opportunities for improvement in the application of arc flash mitigation. The assessors utilized a standardized checklist to determine the level to which established KPIs have been implemented. The checklists are weighted and scored to validate compliance in a consistent manner. This paper demonstrates a structured approach to measure arc flash KPI compliance and highlights some findings and practical examples that can be applied at many oil and gas facilities.
Autors: Ritchie Pragale;Amar Patel;Roger Bresden;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 889 - 894
Publisher: IEEE
 
» Arc Lighting Systems: The First Electrical Distribution Systems [History]
Abstract:
From about 1885 to 1915, the most common means of lighting streets was the use of arc lamps. These lamps and the systems by which they were supplied power were very technologically sophisticated. These were the first electrical distribution systems. The manufacturing companies that made the equipment for arc lighting went on to be the companies that launched the so-called electrical age.
Autors: Robert D. Barnett;
Appeared in: IEEE Power and Energy Magazine
Publication date: Feb 2018, volume: 16, issue:1, pages: 56 - 64
Publisher: IEEE
 
» Arena Function: A Framework for Computing Capacity Bounds in Wireless Networks
Abstract:
Bounds on the capacity of wireless networks often rely on simplifying assumptions and are given in terms of coarse network parameters, such as the number of nodes. While useful due to their simplicity, such bounds can significantly overestimate the achievable capacity in real-world situations, ignoring actual network topology and traffic patterns. The results of this paper improve such analytical results on network capacity in several ways. At the heart of our methodology lies the concept of transmission arenas, which indicates the presence of active transmissions near any given location in the network. This novel space-based approach is well-suited to untangle the interactions of simultaneous transmissions. Avoiding a graph-based model of the network, it opens new avenues of studying capacities. For homogeneous networks, we recover classical bounds. However, our methodology applies to arbitrary networks and can, thus, inform placing and activating of nodes also in the presence of clustering. Our method works with all classical channel models and dimensions. It provides bounds on the transport capacity which involve only high-level knowledge of node locations, such as the length of Euclidean minimum spanning tree. As an additional novelty, we establish bounds on wireless unicast and multicast capacities.
Autors: Alireza Keshavarz-Haddad;Rudolf H. Riedi;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 1134 - 1146
Publisher: IEEE
 
» Array Waveguide Probe Loaded With Split-Ring Resonators for Sizing the Cracks in Metal Surface
Abstract:
Microwave nondestructive testing (NDT) technology developed rapidly, but crack detection in metal surface is facing many troubles, such as hard quantitation and low sensitivity. To solve these problems, this letter proposes a two-cell array waveguide microwave NDT probe with an array of split-ring resonators which operates at 12.5 GHz. It detects quantitatively tiny crack (as low as 0.5 mm) in metal surface. Maximum difference between simulation and experimental results is just 9%. Result shows that the peak distance of has a sensitive and quantitative link with the width and depth of crack. It is shown that the probe is capable of determining the location and dimension of surface cracks of a few millimeter depths and widths.
Autors: Xiaoqing Yang;Yang Yin;Di Zhang;Shiyue Wu;Kama Huang;Jianping Yuan;Zhanxia Zhu;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Feb 2018, volume: 28, issue:2, pages: 171 - 173
Publisher: IEEE
 
» Artificial Noise Assisted Secure Interference Networks With Wireless Power Transfer
Abstract:
Interference alignment (IA) is a remarkable technique to manage interference, and artificial noise (AN) can be utilized to combat one main threat of security, passive eavesdropping. Nevertheless, in the existing schemes, AN is only eliminated at each legitimate receiver, which is a waste of energy. In this paper, we propose an AN-assisted IA scheme with wireless power transfer. In the proposed scheme, AN is generated by each transmitter along with data streams, which can disrupt the eavesdropping without introducing any additional interference. Due to the fact that the transmit power of AN should be high enough to ensure the security, energy harvesting (EH) is also performed in the scheme. A power splitter is equipped at each receiver, which can divide the received signal, including desired signal, interference and AN, into two parts: one for information decoding and the other for EH. To optimize the antieavesdropping performance, the total transmit power of AN is maximized by jointly optimizing the information transmit power and the coefficient of power splitting, with the requirements of signal-to-interference-plus-noise ratio and harvested power satisfied. Due to the nonconvex nature of the problem, a suboptimal solution is also derived to calculate the closed-form solutions with extremely low computational complexity. Extensive simulation results are presented to show the effectiveness of the proposed scheme.
Autors: Nan Zhao;Yang Cao;F. Richard Yu;Yunfei Chen;Minglu Jin;Victor C. M. Leung;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1087 - 1098
Publisher: IEEE
 
» Artificial-Noise-Aided Zero-Forcing Synthesis Approach for Secure Multi-Beam Directional Modulation
Abstract:
Great attention has been paid to wireless communication security in recent years. Directional modulation (DM) is one of the promising secure wireless communication techniques. Multi-beam DM has the capability of sending multiple data streams to cooperative users in different desired directions while distorting signal constellations in all other directions. Dynamic multi-beam DM has been proven to be more secure in real communication scenarios. However, previous synthesis approaches for dynamic multi-beam DM are relatively complex and demand a lot of computations. Therefore, an artificial-noise-aided zero-forcing synthesis approach is proposed. The calculation process of the baseband-weighted vector is simplified using the zero-forcing method, which is closely related to the concept of pseudo-inverse. The dynamic property of multi-beam DM is achieved by randomly changing the artificial noise vector. Compared with previous classical dynamic multi-beam DM synthesis approaches, the proposed approach is more efficient and easier to implement in practical systems with tolerable performance loss.
Autors: Tao Xie;Jiang Zhu;Yang Li;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 276 - 279
Publisher: IEEE
 
» Arya: Operating System Support for Securely Augmenting Reality
Abstract:
Augmented reality (AR) applications capture sensor input from a user’s surroundings and overlay virtual output on their perception of the world, enabling new, immersive experiences. However, this technology raises serious security and privacy risks such as malicious or buggy AR output.
Autors: Kiron Lebeck;Kimberly Ruth;Tadayoshi Kohno;Franziska Roesner;
Appeared in: IEEE Security & Privacy
Publication date: Feb 2018, volume: 16, issue:1, pages: 44 - 53
Publisher: IEEE
 
» ASER Analysis of Hexagonal and Rectangular QAM Schemes in Multiple-Relay Networks
Abstract:
In this paper, analytical lower bound expressions of average symbol error rate (ASER) for general-order hexagonal quadrature amplitude modulation (QAM) and rectangular QAM (RQAM) schemes are derived for multiple amplify-and-forward relay networks over independent and nonidentically distributed Nakagami- fading channels with an integer-valued fading parameter using a well-known cumulative-distribution-function-based approach. Furthermore, ASER expressions for 32-cross QAM, differentially encoded quadriphase shift keying (QPSK), and -QPSK modulation schemes are derived for the considered systems. The asymptotic ASER expression is also derived for the RQAM scheme, which is useful to examine system's diversity order. Numerically evaluated results are verified by Monte Carlo simulation.
Autors: Nagendra Kumar;Praveen Kumar Singya;Vimal Bhatia;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1815 - 1819
Publisher: IEEE
 
» Assessment of Rigid Registration Quality Measures in Ultrasound-Guided Radiotherapy
Abstract:
Image guidance has become the standard of care for patient positioning in radiotherapy, where image registration is often a critical step to help manage patient motion. However, in practice, verification of registration quality is often adversely affected by difficulty in manual inspection of 3-D images and time constraint, thus affecting the therapeutic outcome. Therefore, we proposed to employ both bootstrapping and the supervised learning methods of linear discriminant analysis and random forest to help robustly assess registration quality in ultrasound-guided radiotherapy. We validated both approaches using phantom and real clinical ultrasound images, and showed that both performed well for the task. While learning-based techniques offer better accuracy and shorter evaluation time, bootstrapping requires no prior training and has a higher sensitivity.
Autors: Roozbeh Shams;Yiming Xiao;François Hébert;Matthew Abramowitz;Rupert Brooks;Hassan Rivaz;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Feb 2018, volume: 37, issue:2, pages: 428 - 437
Publisher: IEEE
 
» Asset-Based Dynamic Impact Assessment of Cyberattacks for Risk Analysis in Industrial Control Systems
Abstract:
With the evolution of information, communications, and technologies, modern industrial control systems (ICSs) face more and more cybersecurity issues. This leads to increasingly severe risks in critical infrastructure and assets. Therefore, risk analysis becomes a significant yet not well investigated topic for prevention of cyberattack risks in ICSs. To tackle this problem, a dynamic impact assessment approach is presented in this paper for risk analysis in ICSs. The approach predicts the trend of impact of cybersecurity dynamically from full recognition of asset knowledge. More specifically, an asset is abstracted with properties of construction, function, performance, location, and business. From the function and performance properties of the asset, object-oriented asset models incorporating with the mechanism of common cyberattacks are established at both component and system levels. Characterizing the evolution of behaviors for single asset and system, the models are used to analyze the impact propagation of cyberattacks. Then, from various possible impact consequences, the overall impact is quantified based on the location and business properties of the asset. A special application of the approach is to rank critical system parameters and prioritize key assets according to impact assessment. The effectiveness of the presented approach is demonstrated through simulation studies for a chemical control system.
Autors: Xuan Li;Chunjie Zhou;Yu-Chu Tian;Naixue Xiong;Yuanqing Qin;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Feb 2018, volume: 14, issue:2, pages: 608 - 618
Publisher: IEEE
 
» Asymmetric Bimanual Control of Dual-Arm Exoskeletons for Human-Cooperative Manipulations
Abstract:
In this paper, two upper limbs of an exoskeleton robot are operated within a constrained region of the operational space with unidentified intention of the human operator's motion as well as uncertain dynamics including physical limits. The new human-cooperative strategies are developed to detect the human subject's movement efforts in order to make the robot behavior flexible and adaptive. The motion intention extracted from the measurement of the subject's muscular effort in terms of the applied forces/torques can be represented to derive the reference trajectory of his/her limb using a viable impedance model. Then, adaptive online estimation for impedance parameters is employed to deal with the nonlinear and variable stiffness property of the limb model. In order for the robot to follow a specific impedance target, we integrate the motion intention estimation into a barrier Lyapunov function based adaptive impedance control. Experiments have been carried out to verify the effectiveness of the proposed dual-arm coordination control scheme, in terms of desired motion and force tracking.
Autors: Zhijun Li;Bo Huang;Arash Ajoudani;Chenguang Yang;Chun-Yi Su;Antonio Bicchi;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 264 - 271
Publisher: IEEE
 
» Asymptotic Comparison of ML and MAP Detectors for Multidimensional Constellations
Abstract:
A classical problem in digital communications is to evaluate the symbol error probability (SEP) and bit error probability (BEP) of a multidimensional constellation over an additive white Gaussian noise channel. In this paper, we revisit this problem for nonequally likely symbols and study the behavior of the optimal maximum a posteriori (MAP) detector at asymptotically high signal-to-noise ratios. Exact closed-form asymptotic expressions for SEP and BEP for arbitrary constellations and input distributions are presented. The well-known union bound is proven to be asymptotically tight under general conditions. The performance of the practically relevant maximum likelihood (ML) detector is also analyzed. Although the decision regions with MAP detection converge to the ML regions at high signal-to-noise ratios, the ratio between the MAP and ML detectors in terms of both SEP and BEP approaches a constant, which depends on the constellation and a priori probabilities. Necessary and sufficient conditions for asymptotic equivalence between the MAP and ML detectors are also presented.
Autors: Alex Alvarado;Erik Agrell;Fredrik Brännström;
Appeared in: IEEE Transactions on Information Theory
Publication date: Feb 2018, volume: 64, issue:2, pages: 1231 - 1240
Publisher: IEEE
 
» Asymptotically Optimum Perfect Universal Steganography of Finite Memoryless Sources
Abstract:
A solution to the problem of asymptotically optimum perfect universal steganography of finite memoryless sources with a passive warden is provided, which is then extended to contemplate a distortion constraint. The solution rests on the fact that Slepian’s Variant I permutation coding implements first-order perfect universal steganography of finite host signals with optimum embedding rate. The duality between perfect universal steganography with asymptotically optimum embedding rate and lossless universal source coding with asymptotically optimum compression rate is evinced in practice by showing that permutation coding can be implemented by means of adaptive arithmetic coding. Next, a distortion constraint between the host signal and the information-carrying signal is considered. Such a constraint is essential whenever real-world host signals with memory (e.g., images, audio, or video) are decorrelated to conform to the memoryless assumption. The constrained version of the problem requires trading off embedding rate and distortion. Partitioned permutation coding is shown to be a practical way to implement this trade-off, performing close to an unattainable upper bound on the rate-distortion function of the problem.
Autors: Félix Balado;David Haughton;
Appeared in: IEEE Transactions on Information Theory
Publication date: Feb 2018, volume: 64, issue:2, pages: 1199 - 1216
Publisher: IEEE
 
» Asynchronous Distributed Algorithms for Solving Linear Algebraic Equations
Abstract:
Two asynchronous distributed algorithms are presented for solving a linear equation of the form with at least one solution. The equation is simultaneously and asynchronously solved by agents assuming that each agent knows only a subset of the rows of the partitioned matrix , the estimates of the equation's solution generated by its neighbors, and nothing more. Neighbor relationships are characterized by a time-dependent directed graph whose vertices correspond to agents and whose arcs depict neighbor relationships. Each agent recursively updates its estimate of a solution at its own event times by utilizing estimates generated by its neighbors which are transmitted with delays. The event time sequences of different agents are not assumed to be synchronized. It is shown that for any matrix-vector pair for which the equation has a solution and any repeatedly jointly strongly connected sequence of neighbor graphs defined on the merged sequence of all agents’ event times, the algorithms cause all agents’ estimates to converge exponentially fast to the same solution to . The first algorithm requires a specific initialization step at each agent, and the second algorithm works for arbitrary initializations. Explicit expressions for convergence rates are provided, and a relation between local initializations and limiting consensus solutions is established, which is used to solve the least 2-norm solution.
Autors: Ji Liu;Shaoshuai Mou;A. Stephen Morse;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Feb 2018, volume: 63, issue:2, pages: 372 - 385
Publisher: IEEE
 
» Asynchronous Passive Multisensor System Observability With Unknown Sensor Position
Abstract:
A method is derived for forming composite measurements when the line-of-sight measurements from multiple sensors are asynchronous and the position(s) of one or more passive sensors is (are) unknown. Using the composite measurement, the target position, velocity, and unknown sensor location are estimated. Additionally, general analytical observability conditions are derived.
Autors: Itzik Klein;Yeshaya Lipman;Yaakov Bar-Shalom;
Appeared in: IEEE Transactions on Aerospace and Electronic Systems
Publication date: Feb 2018, volume: 54, issue:1, pages: 369 - 375
Publisher: IEEE
 
» Asynchronous Task-Based Polar Decomposition on Single Node Manycore Architectures
Abstract:
This paper introduces the first asynchronous, task-based formulation of the polar decomposition and its corresponding implementation on manycore architectures. Based on a new formulation of the iterative dynamically-weighted Halley algorithm (QDWH) for the calculation of the polar decomposition, the proposed implementation replaces the original and hostile LU factorization for the condition number estimator by the more adequate factorization to enable software portability across various architectures. Relying on fine-grained computations, the novel task-based implementation is also capable of taking advantage of the identity structure of the matrix involved during the QDWH iterations, which decreases the overall algorithmic complexity. Furthermore, the artifactual synchronization points have been weakened compared to previous implementations, unveiling look-ahead opportunities for better hardware occupancy. The overall QDWH-based polar decomposition can then be represented as a directed acyclic graph (DAG), where nodes represent computational tasks and edges define the inter-task data dependencies. The StarPU dynamic runtime system is employed to traverse the DAG, to track the various data dependencies and to asynchronously schedule the computational tasks on the underlying hardware resources, resulting in an out-of-order task scheduling. Benchmarking experiments show significant improvements against existing state-of-the-art high performance implementations (i.e., Intel MKL and Elemental) for the polar decomposition on latest shared-memory vendors’ systems (i.e., Intel Haswell/Broadwell/Knights Landing, NVIDIA K80/P100 GPUs and - BM Power8), while maintaining high numerical accuracy.
Autors: Dalal Sukkari;Hatem Ltaief;Mathieu Faverge;David Keyes;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Feb 2018, volume: 29, issue:2, pages: 312 - 323
Publisher: IEEE
 
» Asynchronously Coordinated Multi-Timescale Beamforming Architecture for Multi-Cell Networks
Abstract:
Modern wireless devices such as smartphones are pushing the demand for higher wireless data rates. The ensuing increase in wireless traffic demand can be met by a denser deployment of access points, coupled with a coordinated deployment of advanced physical layer techniques to reduce inter-cell interference. Unfortunately, advanced physical layer techniques, e.g., multi-user (MU) MIMO found in 802.11ac and LTE-advanced, are not designed to operate efficiently in a coordinated fashion across multiple densely deployed transmitters. In this paper, we introduce a new coordination architecture, which can achieve high performance gains without the high overhead and deployment cost that usually comes with coordination, thus making the vision of high capacity wireless access via densely deployed transmitters practical. The basic idea is to loosely coordinate nearby transmitters using slow varying channel statistics, while keeping all the functionality which depends on fast varying channel state information and has tight time deadlines locally. We achieve this via a smart combination of analog and digital beamforming using inexpensive front ends, a provably efficient algorithm to select compatible users and analog beams across all transmitters, and backward compatible protocol extensions. Our performance results, which include analysis, simulations, and experiments with software defined radios and directional antennas, show that our approach can achieve the gains of the theoretically optimal coordinated MU-MIMO approach, without the need to either tightly coordinate the clocks of the remote transmitters or meet tight delay constraints.
Autors: Antonios Michaloliakos;Weng Chon Ao;Konstantinos Psounis;Yonglong Zhang;
Appeared in: IEEE/ACM Transactions on Networking
Publication date: Feb 2018, volume: 26, issue:1, pages: 61 - 75
Publisher: IEEE
 
» At the Heart of a Sustainable Energy Transition: The Public Acceptability of Energy Projects
Abstract:
Public acceptability is at the heart of changing the energy system toward a more sustainable way of energy production and use. Without public acceptability and support for changes, a sustainable energy transition is unlikely to be viable. We argue that public acceptability is often addressed too late and should be incorporated into the planning process from the start. Moreover, engineers, policy makers, and project developers tend to misjudge the complexity and causes of public resistance, trying to find the magic bullet to "solve" the lack of public acceptability. Such attempts are likely to be ineffective, or even counterproductive, if they fail to address people's key concerns surrounding energy projects. There is not a one-size-fits-all solution: public acceptability is a dynamic process that depends on the context, the specific project at stake, and the parties involved.
Autors: Goda Perlaviciute;Geertje Schuitema;Patrick Devine-Wright;Bonnie Ram;
Appeared in: IEEE Power and Energy Magazine
Publication date: Feb 2018, volume: 16, issue:1, pages: 49 - 55
Publisher: IEEE
 
» Atmospheric Humidity Sounding Using Differential Absorption Radar Near 183 GHz
Abstract:
A tunable G-band frequency-modulated continuous-wave radar system has been developed and used to perform differential absorption atmospheric humidity measurements for the first time. The radar’s transmitter uses high- power-handling GaAs Schottky diodes to generate between 15–23 dBm over a 10-GHz bandwidth near 183 GHz. By virtue of a high-isolation circular polarization duplexer, the monostatic radar’s receiver maintains a noise figure of about 7 dB even while the transmitter is on. With an antenna gain of 40 dB, high-SNR detection of light rain is achieved out to several hundred meters distance. Owing to the strong spectral dependence of the atmospheric absorption over the upper flank of the 183-GHz water absorption line, range-resolved measurements of absolute humidity can be obtained by ratioing the rain echoes over both range and frequency. Absorption measurements obtained are consistent with models of atmospheric millimeter-wave attenuation, and they demonstrate a new method for improving the accuracy of humidity measurements inside of clouds.
Autors: Ken B. Cooper;Raquel Rodriguez Monje;Luis Millán;Matthew Lebsock;Simone Tanelli;Jose V. Siles;Choonsup Lee;Andrew Brown;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Feb 2018, volume: 15, issue:2, pages: 163 - 167
Publisher: IEEE
 
» Atomic Norm Denoising-Based Joint Channel Estimation and Faulty Antenna Detection for Massive MIMO
Abstract:
We consider joint channel estimation and faulty antenna detection for massive multiple-input multiple-output systems operating in time-division duplexing mode. For systems with faulty antennas, we show that the impact of faulty antennas on uplink data transmission does not vanish even with unlimited number of antennas. However, the signal detection performance can be improved with a priori knowledge on the indices of faulty antennas. This motivates us to propose the approach for simultaneous channel estimation and faulty antenna detection. By exploiting the fact that the degrees of freedom of the physical channel matrix are smaller than the number of free parameters, the channel estimation and faulty antenna detection can be formulated as an extended atomic norm denoising problem and solved efficiently via the alternating direction method of multipliers. Furthermore, we improve the computational efficiency by proposing a fast algorithm and show that it is a good approximation of the corresponding extended atomic norm minimization method. Numerical simulations are provided to compare the performances of the proposed algorithms with several existing approaches and demonstrate the performance gains of detecting the indices of faulty antennas.
Autors: Peng Zhang;Lu Gan;Cong Ling;Sumei Sun;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1389 - 1403
Publisher: IEEE
 
» Attention Recognition in EEG-Based Affective Learning Research Using CFS+KNN Algorithm
Abstract:
The research detailed in this paper focuses on the processing of Electroencephalography (EEG) data to identify attention during the learning process. The identification of affect using our procedures is integrated into a simulated distance learning system that provides feedback to the user with respect to attention and concentration. The authors propose a classification procedure that combines correlation-based feature selection (CFS) and a k-nearest-neighbor (KNN) data mining algorithm. To evaluate the CFS+KNN algorithm, it was test against CFS+C4.5 algorithm and other classification algorithms. The classification performance was measured 10 times with different 3-fold cross validation data. The data was derived from 10 subjects while they were attempting to learn material in a simulated distance learning environment. A self-assessment model of self-report was used with a single valence to evaluate attention on 3 levels (high, neutral, low). It was found that CFS+KNN had a much better performance, giving the highest correct classification rate (CCR) of % for the valence dimension divided into three classes.
Autors: Bin Hu;Xiaowei Li;Shuting Sun;Martyn Ratcliffe;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Feb 2018, volume: 15, issue:1, pages: 38 - 45
Publisher: IEEE
 
» Authenticating Users Through Fine-Grained Channel Information
Abstract:
User authentication is the critical first step in detecting identity-based attacks and preventing subsequent malicious attacks. However, the increasingly dynamic mobile environments make it harder to always apply cryptographic-based methods for user authentication due to their infrastructural and key management overhead. Exploiting non-cryptographic based techniques grounded on physical layer properties to perform user authentication appears promising. In this work, the use of channel state information (CSI), which is available from off-the-shelf WiFi devices, to perform fine-grained user authentication is explored. Particularly, a user-authentication framework that can work with both stationary and mobile users is proposed. When the user is stationary, the proposed framework builds a user profile for user authentication that is resilient to the presence of a spoofer. The proposed machine learning based user-authentication techniques can distinguish between two users even when they possess similar signal fingerprints and detect the existence of a spoofer. When the user is mobile, it is proposed to detect the presence of a spoofer by examining the temporal correlation of CSI measurements. Both office building and apartment environments show that the proposed framework can filter out signal outliers and achieve higher authentication accuracy compared with existing approaches using received signal strength (RSS).
Autors: Hongbo Liu;Yan Wang;Jian Liu;Jie Yang;Yingying Chen;H. Vincent Poor;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Feb 2018, volume: 17, issue:2, pages: 251 - 264
Publisher: IEEE
 
» Automated Detection of Postictal Generalized EEG Suppression
Abstract:
Although there is no strict consensus, some studies have reported that Postictal generalized EEG suppression (PGES) is a potential electroencephalographic (EEG) biomarker for risk of sudden unexpected death in epilepsy (SUDEP). PGES is an epoch of EEG inactivity after a seizure, and the detection of PGES in clinical data is extremely difficult due to artifacts from breathing, movement and muscle activity that can adversely affect the quality of the recorded EEG data. Even clinical experts visually interpreting the EEG will have diverse opinions on the start and end of PGES for a given patient. The development of an automated EEG suppression detection tool can assist clinical personnel in the review and annotation of seizure files, and can also provide a standard for quantifying PGES in large patient cohorts, possibly leading to further clarification of the role of PGES as a biomarker of SUDEP risk. In this paper, we develop an automated system that can detect the start and end of PGES using frequency domain features in combination with boosting classification algorithms. The average power for different frequency ranges of EEG signals are extracted from the prefiltered recorded signal using the fast fourier transform and are used as the feature set for the classification algorithm. The underlying classifiers for the boosting algorithm are linear classifiers using a logistic regression model. The tool is developed using 12 seizures annotated by an expert then tested and evaluated on another 20 seizures that were annotated by 11 experts.
Autors: Wanchat Theeranaew;James McDonald;Bilal Zonjy;Farhad Kaffashi;Brian D. Moseley;Daniel Friedman;Elson So;James Tao;Maromi Nei;Philippe Ryvlin;Rainer Surges;Roland Thijs;Stephan Schuele;Samden Lhatoo;Kenneth A. Loparo;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Feb 2018, volume: 65, issue:2, pages: 371 - 377
Publisher: IEEE
 
» Automated Integrated Robotic Systems for Diagnostics and Test of Electric and Micropropulsion Thrusters
Abstract:
An integrated microcontroller-based data acquisition and robotic actuation suite comprising digital electronics, microcontrollers, custom-made hardware, and accessorial software for diagnostics, and characterization of electric propulsion thrusters in a large vacuum space environment simulator is designed, built, and tested. The components of the characterization suite have been aggregated into modular add-on units for rapid rearrangement and easy customization to suit various applications. The modules include a force calibration system for accurate thrust measurements in various thrust stands, and spatially resolved measurements in a multiprobe array comprising Langmuir and Faraday probes for plume diagnostics of plasma thrusters. Plume and thrust characteristics of a miniaturized Hall-type thruster were successfully measured in situ, enabling users to vary process controls and efficiently optimize the thruster performance. The system revealed a further potential for real-time flight mission diagnostics and control.
Autors: J. W. M. Lim;S. Y. Huang;L. Xu;J. S. Yee;R. Z. Sim;Z. L. Zhang;I. Levchenko;S. Xu;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Feb 2018, volume: 46, issue:2, pages: 345 - 353
Publisher: IEEE
 
» Automated Test Case Generation as a Many-Objective Optimisation Problem with Dynamic Selection of the Targets
Abstract:
The test case generation is intrinsically a multi-objective problem, since the goal is covering multiple test targets (e.g., branches). Existing search-based approaches either consider one target at a time or aggregate all targets into a single fitness function (whole-suite approach). Multi and many-objective optimisation algorithms (MOAs) have never been applied to this problem, because existing algorithms do not scale to the number of coverage objectives that are typically found in real-world software. In addition, the final goal for MOAs is to find alternative trade-off solutions in the objective space, while in test generation the interesting solutions are only those test cases covering one or more uncovered targets. In this paper, we present Dynamic Many-Objective Sorting Algorithm (DynaMOSA), a novel many-objective solver specifically designed to address the test case generation problem in the context of coverage testing. DynaMOSA extends our previous many-objective technique Many-Objective Sorting Algorithm (MOSA) with dynamic selection of the coverage targets based on the control dependency hierarchy. Such extension makes the approach more effective and efficient in case of limited search budget. We carried out an empirical study on 346 Java classes using three coverage criteria (i.e., statement, branch, and strong mutation coverage) to assess the performance of DynaMOSA with respect to the whole-suite approach (WS), its archive-based variant (WSA) and MOSA. The results show that DynaMOSA outperforms WSA in 28 percent of the classes for branch coverage (+8 percent more coverage on average) and in 27 percent of the classes for mutation coverage (+11 percent more killed mutants on average). It outperforms WS in 51 percent of the classes for statement coverage, leading to +11 percent more coverage on average. Moreover, DynaMOSA outperforms its predecessor MOSA for all the three coverage criteria in 19 percent of the classes with +8 percent more code coverage o- average.
Autors: Annibale Panichella;Fitsum Meshesha Kifetew;Paolo Tonella;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Feb 2018, volume: 44, issue:2, pages: 122 - 158
Publisher: IEEE
 
» Automated Tuning of Resonance Frequency in an RF Cavity Resonator
Abstract:
Radio frequency (RF) cavity resonators are one of the key structures in particle accelerators. An RF source transmits required power for acceleration to cavity through waveguides. Due to impedance mismatch, some of the available power generated by the RF source reflects back from the cavity. To save power and provide the maximum accelerating field, it is desirable to minimize this reflected power by equalizing the frequencies of the cavity and source. In this paper, an adaptive gradient based algorithm is developed to automatically reach the minimum value of the reflected power and maintain this condition. The control algorithm is derived through a Lyapunov-based analysis. The proposed adaptive gradient based controller is further compared with a constant gain controller and a classical perturbation-based extremum seeking method. Experimental and simulation results are presented to evaluate the performance of the algorithms in tuning the resonance frequency.
Autors: Zahra Shahriari;Ramona Leewe;Mehrdad Moallem;Ken Fong;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Feb 2018, volume: 23, issue:1, pages: 311 - 320
Publisher: IEEE
 
» Automated Wavelength Alignment in a 4 × 4 Silicon Thermo-Optic Switch Based on Dual-Ring Resonators
Abstract:
We propose and experimentally demonstrate an automated resonance wavelength alignment scheme for an O -band 4 × 4 thermo-optic optical switch using dual-ring resonators. In this scheme, a new control algorithm based on saddle point searching is employed to align dual-input switching elements (SEs) and therefore the 4 × 4 switch. The proposed scheme is proven effective by demonstrating eight routing configurations for two 10-Gb/s data channels. The insertion losses of the three-stage SEs are ≤6.9 dB, and the crosstalk values are below −13.6 dB. Besides, the tolerance of the switch to the wavelength misalignment between the two optical input signals is measured. Negligible performance degradations are observed when the two channels are spaced by 0.05 nm.
Autors: Qingming Zhu;Xinhong Jiang;Yanping Yu;Ruiyuan Cao;Hongxia Zhang;Danping Li;Yanbo Li;Li Zeng;Xuhan Guo;Yong Zhang;Ciyuan Qiu;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 11
Publisher: IEEE
 
» Automatic 2-D/3-D Vessel Enhancement in Multiple Modality Images Using a Weighted Symmetry Filter
Abstract:
Automated detection of vascular structures is of great importance in understanding the mechanism, diagnosis, and treatment of many vascular pathologies. However, automatic vascular detection continues to be an open issue because of difficulties posed by multiple factors, such as poor contrast, inhomogeneous backgrounds, anatomical variations, and the presence of noise during image acquisition. In this paper, we propose a novel 2-D/3-D symmetry filter to tackle these challenging issues for enhancing vessels from different imaging modalities. The proposed filter not only considers local phase features by using a quadrature filter to distinguish between lines and edges, but also uses the weighted geometric mean of the blurred and shifted responses of the quadrature filter, which allows more tolerance of vessels with irregular appearance. As a result, this filter shows a strong response to the vascular features under typical imaging conditions. Results based on eight publicly available datasets (six 2-D data sets, one 3-D data set, and one 3-D synthetic data set) demonstrate its superior performance to other state-of-the-art methods.
Autors: Yitian Zhao;Yalin Zheng;Yonghuai Liu;Yifan Zhao;Lingling Luo;Siyuan Yang;Tong Na;Yongtian Wang;Jiang Liu;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Feb 2018, volume: 37, issue:2, pages: 438 - 450
Publisher: IEEE
 
» Automatic 3D Design for Efficiency Optimization of a Class E Power Amplifier
Abstract:
A design tool, which exploits a state–space model description for the automatic design of a class E power amplifier (PA), is here proposed. The tool provides an automatic optimization of the filter components, just by inserting the design specifications and the starting values. The second step of the automatic iterative tuning allows preserving the highest value of power efficiency. All specifications realize a 3 D matrix, which is able to converge (with 60 iterations in about 3 s) to an optimal solution by using the cross-check of the specifications. Finally, as a case study, an -optimal design has been implemented by using the proposed tool. We compare the analytical design of the class-E PA implemented in TSMC 65 nm CMOS technology, with the state space model technique here described. The new design reaches an efficiency of 87% in simulation, with an increment of 12% respect the original design.
Autors: Daniela De Venuto;Giovanni Mezzina;Jan Rabaey;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Feb 2018, volume: 65, issue:2, pages: 201 - 205
Publisher: IEEE
 
» Automatic Annotation of Text with Pictures
Abstract:
The vast array of information available on the Internet makes it challenging to quickly determine the importance and relevance of content. Text picturing is a cognitive aid that can help with text understanding, as it helps users decide if the text deserves a closer look by showing relevant pictures along with the text.
Autors: J. Kent Poots;Ebrahim Bagheri;
Appeared in: IT Professional
Publication date: Feb 2018, volume: 20, issue:1, pages: 36 - 44
Publisher: IEEE
 
» Automatic Calcium Scoring in Low-Dose Chest CT Using Deep Neural Networks With Dilated Convolutions
Abstract:
Heavy smokers undergoing screening with low-dose chest CT are affected by cardiovascular disease as much as by lung cancer. Low-dose chest CT scans acquired in screening enable quantification of atherosclerotic calcifications and thus enable identification of subjects at increased cardiovascular risk. This paper presents a method for automatic detection of coronary artery, thoracic aorta, and cardiac valve calcifications in low-dose chest CT using two consecutive convolutional neural networks. The first network identifies and labels potential calcifications according to their anatomical location and the second network identifies true calcifications among the detected candidates. This method was trained and evaluated on a set of 1744 CT scans from the National Lung Screening Trial. To determine whether any reconstruction or only images reconstructed with soft tissue filters can be used for calcification detection, we evaluated the method on soft and medium/sharp filter reconstructions separately. On soft filter reconstructions, the method achieved F1 scores of 0.89, 0.89, 0.67, and 0.55 for coronary artery, thoracic aorta, aortic valve, and mitral valve calcifications, respectively. On sharp filter reconstructions, the F1 scores were 0.84, 0.81, 0.64, and 0.66, respectively. Linearly weighted kappa coefficients for risk category assignment based on per subject coronary artery calcium were 0.91 and 0.90 for soft and sharp filter reconstructions, respectively. These results demonstrate that the presented method enables reliable automatic cardiovascular risk assessment in all low-dose chest CT scans acquired for lung cancer screening.
Autors: Nikolas Lessmann;Bram van Ginneken;Majd Zreik;Pim A. de Jong;Bob D. de Vos;Max A. Viergever;Ivana Išgum;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Feb 2018, volume: 37, issue:2, pages: 615 - 625
Publisher: IEEE
 
» Automatic Correction of Dynamic Power Management Architecture in Modern Processors
Abstract:
The increasing demand for lower power forces designers to use sophisticated power management strategies such as multivoltage and power gating which are often accompanied with many design bugs. Correcting such bugs can be a time-consuming process that requires considerable manual efforts. In this paper, we propose a scalable automated method for correcting dynamic power management architectures by an incremental SAT-based mechanism. First, an initial counterexample (CEX) is generated by checking the equivalency between the specification model of the processor and its buggy implementation model. Then, we find two candidate solutions instead of one to satisfy this CEX. If two solutions are not equivalent, we generate new CEX in an iterative process which effectively converges into the final solution. The proposed method enables designers to correct multiple bugs such as missing isolation cells between two power domains, disordering in the sequence of control signals, error in the data restoring or saving, and powering off in always-on domains which are not addressed by existing methods. We have shown the effectiveness of our method on modern processors supporting complex power management mechanisms. The results confirm that our proposed method, respectively, reduces symbolic simulation steps and runtime by and compared to the state-of-the-art methods.
Autors: Reza Sharafinejad;Bijan Alizadeh;Zainalabedin Navabi;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Feb 2018, volume: 26, issue:2, pages: 308 - 318
Publisher: IEEE
 
» Automatic Defect Detection of Fasteners on the Catenary Support Device Using Deep Convolutional Neural Network
Abstract:
The excitation and vibration triggered by the long-term operation of railway vehicles inevitably result in defective states of catenary support devices. With the massive construction of high-speed electrified railways, automatic defect detection of diverse and plentiful fasteners on the catenary support device is of great significance for operation safety and cost reduction. Nowadays, the catenary support devices are periodically captured by the cameras mounted on the inspection vehicles during the night, but the inspection still mostly relies on human visual interpretation. To reduce the human involvement, this paper proposes a novel vision-based method that applies the deep convolutional neural networks (DCNNs) in the defect detection of the fasteners. Our system cascades three DCNN-based detection stages in a coarse-to-fine manner, including two detectors to sequentially localize the cantilever joints and their fasteners and a classifier to diagnose the fasteners’ defects. Extensive experiments and comparisons of the defect detection of catenary support devices along the Wuhan–Guangzhou high-speed railway line indicate that the system can achieve a high detection rate with good adaptation and robustness in complex environments.
Autors: Junwen Chen;Zhigang Liu;Hongrui Wang;Alfredo Núñez;Zhiwei Han;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Feb 2018, volume: 67, issue:2, pages: 257 - 269
Publisher: IEEE
 
» Automatic Identification of Driver’s Smartphone Exploiting Common Vehicle-Riding Actions
Abstract:
Texting or browsing the web on a smartphone while driving, called distracted driving, significantly increases the risk of car accidents. There have been a number of proposals for the prevention of distracted driving, but none of them has addressed its important challenges completely and effectively. To remedy this deficiency, we present an event-driven solution, called Automatic Identification of Driver’s Smartphone (AIDS), which identifies a driver’s smartphone by analyzing and fusing the phone’s sensory information related to common vehicle-riding activities, such as walking toward the vehicle, standing near the vehicle while opening a vehicle door, entering the vehicle, closing the door, and starting the engine. AIDS extracts features useful for identification of the driver’s phone from diverse sensors available in commodity smartphones. It identifies the driver’s phone before the vehicle leaves its parked spot, and differentiates seated (front or rear) rows in a vehicle by analyzing the subtle electromagnetic field spikes caused by the starting of the engine. To evaluate the feasibility and adaptability of AIDS, we have conducted extensive experiments: a prototype of AIDS was distributed to 12 participants, both males and females in their 20 and 30s, who have driven seven different vehicles for three days in real-world environments. Our evaluation results show that AIDS identified the driver’s phone with an 83.3-93.3 percent true positive rate while achieving a 90.1-91.2 percent true negative rate at a marginal increase of the phone’s energy consumption.
Autors: Homin Park;DaeHan Ahn;Taejoon Park;Kang G. Shin;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Feb 2018, volume: 17, issue:2, pages: 265 - 278
Publisher: IEEE
 
» Automatic Registration of Terrestrial and Airborne Point Clouds Using Building Outline Features
Abstract:
Terrestrial laser scanner (TLS) and airborne laser scanner (ALS) can effectively capture point clouds from side or top view, respectively. Registering point clouds captured by ALS and TLS provides an integrated data source for three-dimensional (3-D) reconstruction. However, registration is difficult between TLS and ALS data because of the differences in scanning perspectives, scanning area, and spatial resolutions. A new method that can achieve automatic horizontal registration with ALS and TLS data based on building contour features is proposed in this study. The key steps include horizontal and vertical registrations based on 2-D building outlines and ground planes in ALS and TLS data, respectively. First, the 2-D building outlines are extracted from both ALS and TLS data. Second, the horizontal registration is accomplished by using the four-point congruent sets method for initial registration and the global optimization method for refined registration. Finally, the ground surface in the same region of ALS and TLS data are fitted for vertical registration, and the average elevation difference between the corresponding ground planes is calculated as the translation parameter value in the vertical direction. The results indicate that the proposed method can successfully match ALS and TLS data with an accuracy of 0.2-m both in the horizontal and vertical directions.
Autors: Xiaolong Cheng;Xiaojun Cheng;Quan Li;Liwei Ma;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Feb 2018, volume: 11, issue:2, pages: 628 - 638
Publisher: IEEE
 
» Autonomous network and IT resource management for geographically distributed data centers
Abstract:
As enterprises struggle to meet the demand for elastic cloud computing services in distributed data centers (DCs), a significant portion of the total expenditure is spent on the procurement and maintenance of server and network equipment. Network and server resource utilization efficiency is therefore crucial to minimize overall costs and increase return on investment. We present an adaptive and synergistic management of both network and IT resources with an autonomous control plane on a converged inter/ intra-DC network to address this issue. The control plane uses its awareness of both network and IT resource usage to provide dynamic resource allocations to meet quality of service guarantees, while also allowing for reduction in operational expenses by consolidating virtual machines to maintain high CPU usage on the active servers. We built a three-node inter-DC experimental testbed to demonstrate the feasibility of our concept and show that our algorithm successfully provisions both network resources and consolidates IT resources under various load conditions.
Autors: Yiwen Shen;Payman Samadi;Keren Bergman;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Feb 2018, volume: 10, issue:2, pages: A225 - A231
Publisher: IEEE
 
» Avoiding Matrix Inversion in Takagi–Sugeno-Based Advanced Controllers and Observers
Abstract:
Many of the recent advances on control and estimation of systems described by Takagi–Sugeno (TS) fuzzy models are based on matrix inversion, which could be a trouble in the case of real-time implementation. This paper is devoted to the development of alternative solutions to this matrix inversion problem in the discrete-time case. Two different methods are proposed: The first one relies on replacing the matrix inversion by multiple sums and the second methodology is based on an estimation of the matrix inversion by an observer structure. For the first methodology, a new class of controllers and observers are introduced which are called, respectively, the counterpart of an advanced TS-based (CATS) controller and the replica of an advanced TS-based (RATS) observer. Instead of relaxations for the linear matrix inequalities conditions, an original use of the membership functions is presented. In the second methodology, it is proposed the estimation-based control law for approximating TS-based (ECLATS) controller that uses a fuzzy state observer. The Lyapunov theory is used to ensure stability conditions for either the closed-loop system as well as the estimation error. Numerical examples and comparisons highlight the efficiency of the procedures that can be used to replace any inverted matrix in any advanced fuzzy controller or observer. Finally, advantages and drawbacks of the proposed method are discussed.
Autors: Thomas Laurain;Jimmy Lauber;Reinaldo Martinez Palhares;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Feb 2018, volume: 26, issue:1, pages: 216 - 225
Publisher: IEEE
 
» Azimuth Location Deambiguity for SAR Ground Moving Targets via Coprime Adjacent Arrays
Abstract:
The ground moving target's radial velocity estimation based on the interferometric phase in a multichannel synthetic aperture radar (SAR) system suffers from 2π modulo folding, resulting in the target's azimuth location ambiguity in the SAR image. To address this problem, a novel coprime adjacent arrays SAR (CAA-SAR) is proposed in this paper. The two sparse uniform subarrays constituting the CAA are arranged adjacently with a conjunct element, then a virtual array can be obtained with much more virtual elements and smaller element spacing, which will help to solve the azimuth location ambiguity. After ground clutter suppression, multiple pixels’ samplings are utilized based on the MUSIC algorithm for estimating radial velocity as well as azimuth shift by exploiting all virtual elements of CAA-SAR. Compared with the existing nonuniform linear array SAR method based on Chinese remainder theorem, the CAA-SAR can obtain a better accuracy with the same number of elements in a larger sparse configuration, or use fewer elements to obtain an approximate accuracy in almost the same physical aperture. Compared with the coprime arrays SAR, the CAA-SAR has a better accuracy due to its larger number of unique virtual elements and longer physical aperture. Finally, some results of numerical experiments are provided to demonstrate the effectiveness of the proposed method.
Autors: Zu-Zhen Huang;Ze-Gang Ding;Jia Xu;Tao Zeng;Li Liu;Zhi-Rui Wang;Chang-Hui Feng;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Feb 2018, volume: 11, issue:2, pages: 551 - 561
Publisher: IEEE
 
» Bad Data Detection Using Linear WLS and Sampled Values in Digital Substations
Abstract:
Smart Grids employ intelligent control applications that require high quality data: fast, secure, and error free. Several researchers have focused on providing techniques for low latency and secured data links for these applications. Bad data detection is however generally provided only at the central level due to limitations in legacy technologies employed in many substations. With the introduction of IEC61850 data sharing within the substation becomes more flexible and transparent allowing more sophisticated management of data quality. Hence, this paper proposes a substation level bad data detection algorithm to facilitate also these types of requirements from applications. The algorithm is based on automatically detecting the substation topology by parsing standard substation description files and online state of circuit breakers and disconnectors. By applying linear weighted least square based state estimation algorithm, bad data from failing current transformers (CT) can be detected. By conducting the verification of different types of bad data, the results show the output of bad data detection algorithm provides higher accuracy than output from both measurement and protective CT in both static and faulty situations.
Autors: Yiming Wu;Yong Xiao;Fabian Hohn;Lars Nordström;Jianping Wang;Wei Zhao;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 150 - 157
Publisher: IEEE
 
» Bad Security Metrics Part 1: Problems
Abstract:
This two-part series focuses on defining the problem of questionable metrics conceptually and revealing a path forward for improving both security metrics and how people use them.
Autors: David Flater;
Appeared in: IT Professional
Publication date: Feb 2018, volume: 20, issue:1, pages: 64 - 68
Publisher: IEEE
 
» Balanced Filter With Wideband Common-Mode Suppression in Groove Gap Waveguide Technology
Abstract:
This letter is focused on the design and realization of balanced bandpass filters (BPFs) in gap waveguide technology. The procedure of filter design and resonance-mode selection to achieve the desired differential bandpass behavior with intrinsic deep and wideband common-mode suppression is explained. A third-order differential BPF is designed and fabricated for demonstration. Agreement between the computed and measured results validates the concept and the design procedure.
Autors: Ali K. Horestani;Mahmoud Shahabadi;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Feb 2018, volume: 28, issue:2, pages: 132 - 134
Publisher: IEEE
 

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