Electrical and Electronics Engineering publications abstract of: 09-2017 sorted by title, page: 4

» Capacity of Multilevel NAND Flash Memory Channels
Abstract:
In this paper, we initiate a first information-theoretic study on multilevel NAND flash memory channels with intercell interference. More specifically, for a multilevel NAND flash memory channel under mild assumptions, we first prove that such a channel is indecomposable and it features asymptotic equipartition property; we then further prove that stationary processes achieve its information capacity, and consequently, as the order tends to infinity, its Markov capacity converges to its information capacity; eventually, we establish that its operational capacity is equal to its information capacity. Our results suggest that it is highly plausible to apply the ideas and techniques in the computation of the capacity of finite-state channels, which are relatively better explored, to that of the capacity of multilevel NAND flash memory channels.
Autors: Yonglong Li;Aleksandar Kavčić;Guangyue Han;
Appeared in: IEEE Transactions on Information Theory
Publication date: Sep 2017, volume: 63, issue:9, pages: 5934 - 5953
Publisher: IEEE
 
» Career Management: Ten Important Things to Keep in Mind
Abstract:
Your career can serve as an expression of who you are, what values you have, and what you seek to accomplish. Certainly compensation is a consideration. However, in my over 30 years as an engineer, manager, and executive in the electric utility industry, the most fulfilled, engaging, and passionate individuals I have met, regardless of "rank," have been those whose work was most closely aligned with their personal interests and beliefs.
Autors: Christopher E. Root;
Appeared in: IEEE Potentials
Publication date: Sep 2017, volume: 36, issue:5, pages: 13 - 16
Publisher: IEEE
 
» Careers in Signal Processing: A Diverse Field Impacting the Future [President's Message]
Abstract:
Autors: Rabab Ward;
Appeared in: IEEE Signal Processing Magazine
Publication date: Sep 2017, volume: 34, issue:5, pages: 5 - 11
Publisher: IEEE
 
» Carrier Aggregation of Three OFDM Signals Using a Single Oscillator and I/Q Modulator
Abstract:
In this paper, a novel method is presented, which makes carrier aggregation (CA) using a single local oscillator and an in-phase/quadrature (I/Q) modulator, possible. Three component carriers with orthogonal frequency division multiplexing are generated at 2.2, 2.5, and 2.9 GHz to show the feasibility of the method for the worst case scenario that is the interband CA. A special procedure to compensate the I/Q imbalances specific to this method is explained as well. Moreover, according to Nyquist criterion, the signal should have a sampling rate at least twice the signal highest frequency. In this method, the sampling rate of the digital-to-analog converter is significantly reduced, because, the baseband signal is distributed over negative and positive frequencies. In addition, the demodulation process of these frequency-aggregated signals using a three-phase demodulator is explained and experimental results are presented.
Autors: Mohammad Abdi Abyaneh;Bernard Huyart;Jean-Christophe Cousin;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3351 - 3359
Publisher: IEEE
 
» CDN-As-a-Service Provision Over a Telecom Operator’s Cloud
Abstract:
We present the design and implementation of a content-delivery-network-as-a-service (CDNaaS) architecture, which allows a telecom operator to open up its cloud infrastructure for content providers to deploy virtual content delivery network (CDN) instances on demand, at regions where the operator has presence. Using northbound REST APIs, content providers can express performance requirements and demand specifications, which are translated to an appropriate service placement on the underlying cloud substrate. Our architecture is extensible, supporting various different CDN flavors, and, in turn, different schemes for cloud resource allocation and management. In order to decide on the latter in an optimal manner from an infrastructure cost and a service quality perspective, knowledge of the performance capabilities of the underlying technologies, and compute resources is critical. Therefore, to gain insight which can be applied to the design of such mechanisms, but also with further implications on service pricing and SLA design, we carry out a measurement campaign to evaluate the capabilities of key enabling technologies for CDNaaS provision. In particular, we focus on virtualization and containerization technologies for implementing virtual CDN functions to deliver a generic HTTP service, as well as an HTTP video streaming one, empirically capturing the relationship between performance and service workload, both from a system operator and a user-centric viewpoint.
Autors: Pantelis A. Frangoudis;Louiza Yala;Adlen Ksentini;
Appeared in: IEEE Transactions on Network and Service Management
Publication date: Sep 2017, volume: 14, issue:3, pages: 702 - 716
Publisher: IEEE
 
» Celestial Signals: Are Low-Noise Amplifiers the Future for Millimeter-Wave Radio Astronomy Receivers?
Abstract:
Radio emission emanating from celestial sources was first detected by Karl Jansky during the 1930s. Using primitive radio instrumentation coupled to a relatively small aperture telescope, Jansky mapped portions of the Milky Way and established the field of radio astronomy. Thus was born a branch of modern astrophysics that has allowed the study of radio emission from cosmic sources and revolutionized our understanding of the universe.
Autors: David Cuadrado-Calle;Danielle George;Brian Ellison;Gary A. Fuller;Keiran Cleary;
Appeared in: IEEE Microwave Magazine
Publication date: Sep 2017, volume: 18, issue:6, pages: 90 - 99
Publisher: IEEE
 
» Centralized Random Backoff for Collision Resolution in Wi-Fi Networks
Abstract:
Wi-Fi devices operate following the 802.11 distributed coordination function in order to fairly use the channel that the devices share. However, the throughput performance of the Wi-Fi networks is known to be degraded due to packet collisions. So, we propose a novel multiple access protocol, called centralized random backoff (CRB) for collision-free Wi-Fi networks. In CRB, after a successful reception of a data frame from a station, the access point allocates a unique backoff state to the station by means of the ACK frame. We evaluate its performance by comparing to that of a deterministic backoff mechanism. Evaluation results show that CRB significantly improves the throughput performance by reducing collisions, and it allows a larger number of nodes to operate in a collision-free state without dynamic parameter adjustment.
Autors: Jinho D. Kim;David I. Laurenson;John S. Thompson;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Sep 2017, volume: 16, issue:9, pages: 5838 - 5852
Publisher: IEEE
 
» Challenge Your Limits [Pathways]
Abstract:
Discusses the importance of an education despite the challenges that people may face in order to achieve their career goals.
Autors: David Eng;
Appeared in: IEEE Industry Applications Magazine
Publication date: Sep 2017, volume: 23, issue:5, pages: 76 - 77
Publisher: IEEE
 
» Challenging the Best HEVC Fractional Pixel FPGA Interpolators With Reconfigurable and Multifrequency Approximate Computing
Abstract:
Applicable in different fields and markets, low energy high efficiency video coding (HEVC) codecs and their constituting elements have been heavily studied. Fractional pixel interpolation is one of its most costly blocks. In this letter, a field programmable gate array implementation of HEVC fractional pixel interpolation, outperforming literature solutions, is proposed. Approximate computing, in conjunction with hardware reconfiguration, guarantees a tunable interpolation system offering an energy versus quality tradeoff to further reduce energy.
Autors: Carlo Sau;Francesca Palumbo;Maxime Pelcat;Julien Heulot;Erwan Nogues;Daniel Menard;Paolo Meloni;Luigi Raffo;
Appeared in: IEEE Embedded Systems Letters
Publication date: Sep 2017, volume: 9, issue:3, pages: 65 - 68
Publisher: IEEE
 
» Chance-Constrained AC Optimal Power Flow for Distribution Systems With Renewables
Abstract:
This paper focuses on distribution systems featuring renewable energy sources (RESs) and energy storage systems, and presents an AC optimal power flow (OPF) approach to optimize system-level performance objectives while coping with uncertainty in both RES generation and loads. The proposed method hinges on a chance-constrained AC OPF formulation, where probabilistic constraints are utilized to enforce voltage regulation with prescribed probability. A computationally more affordable convex reformulation is developed by resorting to suitable linear approximations of the AC power-flow equations as well as convex approximations of the chance constraints. The approximate chance constraints provide conservative bounds that hold for arbitrary distributions of the forecasting errors. An adaptive strategy is then obtained by embedding the proposed AC OPF task into a model predictive control framework. Finally, a distributed solver is developed to strategically distribute the solution of the optimization problems across utility and customers.
Autors: Emiliano Dall’Anese;Kyri Baker;Tyler Summers;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3427 - 3438
Publisher: IEEE
 
» Chance-Constrained Two-Stage Unit Commitment Under Uncertain Load and Wind Power Output Using Bilinear Benders Decomposition
Abstract:
In this paper, we study unit commitment (UC) problems considering the uncertainty of load and wind power generation. UC problem is formulated as a chance-constrained two-stage stochastic programming problem where the chance constraint is used to restrict the probability of load imbalance. In addition to the conventional mixed integer linear programming formulation using Big-M, we present the bilinear mixed integer formulation of chance constraint, and then derive its linear counterpart using the McCormick linearization method. Then, we develop a bilinear variant of the Benders decomposition method, which is an easy-to-implement algorithm, to solve the resulting large-scale linear counterpart. Our results on typical IEEE systems demonstrate that (i) the bilinear mixed integer programming formulation is stronger than the conventional one and (ii) the proposed Benders decomposition algorithm is generally an order of magnitude faster than using a professional solver to directly compute both linear and bilinear chance-constrained UC models.
Autors: Yao Zhang;Jianxue Wang;Bo Zeng;Zechun Hu;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3637 - 3647
Publisher: IEEE
 
» Change is Afoot: Applying Change Management Theories to Self-Organizing Socio-Technical Systems
Abstract:
Socio-technical systems are here to stay. They are going to become more important and more engrained in our daily lives. Even the relatively mundane examples we see these days have transformed the way we communicate, look up, and share knowledge, and the ways we choose our restaurants, our rides, and our vacations. Computersupported cooperative work is already transforming the workplace. Personal health and fitness applications allow us to observe our bodies and share this information within a social network that provides both praise and control. Larger-scale solutions are right around the corner. The technical feasibility of such systems is no longer under debate. Users seem to be willing to give up their data and at least some control for the benefits these socio-technical systems undoubtedly bring.
Autors: Jan-Philipp Steghofer;
Appeared in: IEEE Technology and Society Magazine
Publication date: Sep 2017, volume: 36, issue:3, pages: 56 - 62
Publisher: IEEE
 
» Changes to the Editorial Board
Abstract:
Prof. Jurriaan Schmitz has decided to step down from the editorial board. On behalf of IEEE Electron Device Letters staff and readers, I would like to express appreciation for his diligent service to the journal over the past five years.
Autors: Tsu-Jae King Liu;
Appeared in: IEEE Electron Device Letters
Publication date: Sep 2017, volume: 38, issue:9, pages: 1191 - 1191
Publisher: IEEE
 
» Channel Coding for Nonvolatile Memory Technologies: Theoretical Advances and Practical Considerations
Abstract:
Every bit of information in a storage or memory device is bound by a multitude of performance specifications, and is subject to a variety of reliability impediments. At the other end, the physical processes tamed to remember our bits offer a constant source of risk to their reliability. These include a variety of noise sources, access restrictions, intercell interferences, cell variabilities, and many more issues. Tying together this vector of performance figures with that vector of reliability issues is a rich matrix of emerging coding tools and techniques. Channel coding schemes ensure target reliability and performance and have been at the core of memory systems since their nascent age. In this survey, we first overview the fundamentals of channel coding and summarize well-known codes that have been used in nonvolatile memories (NVMs). Next, we demonstrate why the conventional coding approaches ubiquitously based on symmetric channel models and optimization for the Hamming metric fail to address the needs of modern memories. We then discuss several recently proposed innovative coding schemes. Behind each coding scheme lies an interesting theoretical framework, building on deep ideas from mathematics and the information sciences. We also survey some of the most fascinating bridges between deep theory and storage performance. While the focus of this survey is primarily on the pervasive multilevel NAND Flash, we envision that other benefiting memory technologies will include phase change memory, resistive memories, and others.
Autors: Lara Dolecek;Yuval Cassuto;
Appeared in: Proceedings of the IEEE
Publication date: Sep 2017, volume: 105, issue:9, pages: 1705 - 1724
Publisher: IEEE
 
» Channel Estimation for 3-D Lens Millimeter Wave Massive MIMO System
Abstract:
Channel estimation for 3-D lens millimeter wave massive MIMO system is investigated. First, the structure of beamspace channel is analyzed to show that the dominant entries of beamspace channel matrix form a dual crossing (DC) shape. Then, a DC-based channel estimation algorithm is proposed to iteratively refine the selection of dominant entries until the stop condition is met. Simulation results show that the DC-based algorithm outperforms the existing algorithms, including orthogonal matching pursuit and adaptive support detection (ASD). At signal-to-noise ratio of 15 dB, the DC-based algorithm has 57.7% improvement in terms of normalized mean squared error compared with ASD while the computational complexity is only half of ASD due to fast computation of least squares estimation.
Autors: Wenyan Ma;Chenhao Qi;
Appeared in: IEEE Communications Letters
Publication date: Sep 2017, volume: 21, issue:9, pages: 2045 - 2048
Publisher: IEEE
 
» Channel Estimation for Hybrid Architecture-Based Wideband Millimeter Wave Systems
Abstract:
Hybrid analog and digital precoding allows millimeter wave (mmWave) systems to achieve both array and multiplexing gain. The design of the hybrid precoders and combiners, though, is usually based on the knowledge of the channel. Prior work on mmWave channel estimation with hybrid architectures focused on narrowband channels. Since mmWave systems will be wideband with frequency selectivity, it is vital to develop channel estimation solutions for hybrid architectures-based wideband mmWave systems. In this paper, we develop a sparse formulation and compressed sensing-based solutions for the wideband mmWave channel estimation problem for hybrid architectures. First, we leverage the sparse structure of the frequency-selective mmWave channels and formulate the channel estimation problem as a sparse recovery in both time and frequency domains. Then, we propose explicit channel estimation techniques for purely time or frequency domains and for combined time/frequency domains. Our solutions are suitable for both single carrier-frequency domain equalization and orthogonal frequency-division multiplexing systems. Simulation results show that the proposed solutions achieve good channel estimation quality, while requiring small training overhead. Leveraging the hybrid architecture at the transceivers gives further improvement in estimation error performance and achievable rates.
Autors: Kiran Venugopal;Ahmed Alkhateeb;Nuria González Prelcic;Robert W. Heath;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Sep 2017, volume: 35, issue:9, pages: 1996 - 2009
Publisher: IEEE
 
» Channel Gain Cartography for Cognitive Radios Leveraging Low Rank and Sparsity
Abstract:
Channel gain cartography aims at inferring the channel gains between two arbitrary points in space based on the measurements (samples) of the gains collected by a set of radios deployed in the area. Channel gain maps are useful for various sensing and resource allocation tasks essential for the operation of cognitive radio networks. In this paper, the channel gains are modeled as the tomographic accumulations of an underlying spatial loss field (SLF), which captures the attenuation in the signal strength due to the obstacles in the propagation path. In order to estimate the map accurately with a relatively small number of measurements, the SLF is postulated to have a low-rank structure possibly with sparse deviations. Efficient batch and online algorithms are derived for the resulting map reconstruction problem. Comprehensive tests with both synthetic and real data sets corroborate that the algorithms can accurately reveal the structure of the propagation medium, and produce the desired channel gain maps.
Autors: Donghoon Lee;Seung-Jun Kim;Georgios B. Giannakis;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Sep 2017, volume: 16, issue:9, pages: 5953 - 5966
Publisher: IEEE
 
» Channel Pre-Inversion and Max-SINR Vector Perturbation for Large-Scale Broadcast Channels
Abstract:
We study channel pre-inversion and vector perturbation (VP) schemes for large-scale broadcast channels, wherein a transmitter has transmit antennas and is transmitting to single-antenna non-cooperating receivers. We provide results which predict the capacity of MMSE pre-inversion as . We construct a new VP strategy, max-SINR VP (MSVP), which maximizes a sharp estimate of the signal-to-interference-plus-noise ratio. We provide results which predict the performance of MSVP and demonstrate that MSVP outperforms other VP methods. Lastly, we combine MSVP with the low-complexity sorted QR precoding method to show that MSVP has the potential to efficiently deliver data to a very large number of users at close to channel capacity.
Autors: David A. Karpuk;Peter Moss;
Appeared in: IEEE Transactions on Broadcasting
Publication date: Sep 2017, volume: 63, issue:3, pages: 494 - 506
Publisher: IEEE
 
» Channels With Cooperation Links That May Be Absent
Abstract:
It is well known that cooperation between users in a communication network can lead to significant performance gains. A common assumption in past works is that all the users are aware of the resources available for cooperation, and know exactly to what extent these resources can be used. Unfortunately, in many modern communication networks, the availability of cooperation links cannot be guaranteed a priori, due to the dynamic nature of the network. In this paper, a family of models is suggested where the cooperation links may or may not be present. Coding schemes are devised that exploit the cooperation links if they are present, and can still operate (although at reduced rates) if cooperation is not possible.
Autors: Wasim Huleihel;Yossef Steinberg;
Appeared in: IEEE Transactions on Information Theory
Publication date: Sep 2017, volume: 63, issue:9, pages: 5886 - 5906
Publisher: IEEE
 
» Characteristic Analysis of Subsynchronous Resonance in Practical Wind Farms Connected to Series-Compensated Transmissions
Abstract:
The emerging subsynchronous resonance (SSR) caused by the interaction of wind turbine generators (WTGs) with series compensation has aroused great concerns. For this particular issue, this paper is aimed to fill the gap between theoretical studies and actual observations. By analyzing the field data of 58 SSR events captured in a practical wind power system and examining the observed dynamics with previous theoretical results, the mechanism and characteristics of SSR are revealed in a more explicit and substantial way. The necessary conditions and dominant influential factors are identified and the underlying reasons are discovered. Theoretically derived as well as practically measured impedance models have demonstrated that the converter control of doubly fed induction generator (DFIG) produces negative resistance at the slip frequency and thus causes unstable SSR; while permanent magnet synchronous generators and self-excited induction generators are just passively engaged in those SSR incidents. The distribution of the oscillation frequency has also been examined with field measurements. It is discovered that WTGs at different locations participate into the same SSR mode and their frequencies are not fixed but keep changing with the time, the variation of grid topology, and the number of online generators.
Autors: Xiaorong Xie;Xu Zhang;Huakun Liu;Hui Liu;Yunhong Li;Chuanyu Zhang;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 1117 - 1126
Publisher: IEEE
 
» Characteristics and Restraining Method of Fast Transient Inrush Fault Currents in Synchronverters
Abstract:
Large transient inrush fault current in a synchronverter during a short-circuit fault can potentially damage the inverter and cause grid instability. It is therefore important to study the characteristics of and the way to restrain the inrush fault current. This paper investigates the characteristics of the synchronverter inrush fault current and proposes a new control method based on mode switching to protect synchronverters. First, an ideal voltage source inverter instantaneous inrush current calculation method for a grid symmetrical short circuit is discussed. Then, based on the inertia of synchronverter, the approximate calculation of the synchronverter instantaneous inrush current is described. The results show that the synchronverter's inrush current mainly consists of a gradually attenuated periodic component and a dc component when the phased voltage symmetry is lost. In our proposed new control approach, the synchronverter switches to the hysteresis controller to limit the output current quickly while staying connected to the grid, and supporting the grid voltage simultaneously. Simulation and experiment results verify the validity of the theoretical analysis.
Autors: Zhikang Shuai;Wen Huang;Chao Shen;Jun Ge;Z. John Shen;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7487 - 7497
Publisher: IEEE
 
» Characteristics of Planar and Conformal Contact GaAs Core–Shell Nanowire Array Solar Cells
Abstract:
As the transparent contact in radial p-n junction core-shell nanowire array solar cells can be either planar or conformal, the characteristics of these two types of device structure would be very different since conformal contact gives rise to severe band bending. Although radial p-n junction GaAs core-shell nanowire array solar cell with conformal transparent contact has been briefly inferred to have an inferior performance compared to the same nanowire array solar cell with planar transparent contact, the characteristics of these two types of radial p-n junction core-shell nanowire array solar cells are not known. Furthermore, it is unknown how the performance of these two types of solar cell compares with each other when the nanowire design parameters are optimized according to device physics of these two types of solar cell. In this paper, it is shown that radial p-n junction GaAs core-shell nanowire array solar cells with planar transparent contact are prone to carrier avalanche breakdown, and hence have a limited range of doping density. On the other hand, carrier diffusion in radial p-n junction GaAs core-shell nanowire array solar cells with conformal transparent contact is poor and hence requires a high doping to the core in order to increase the output voltage. All in all, this paper reveals that either type of transparent contact structure yields essentially the same energy conversion efficiency as long as the radial p-n junction GaAs core-shell nanowires are designed to suit the device physics of the type of transparent contact.
Autors: Cheng Guan Lim;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3696 - 3705
Publisher: IEEE
 
» Characterization and Modeling of K-Band Coplanar Waveguides Digitally Manufactured Using Pulsed Picosecond Laser Machining of Thick-Film Conductive Paste
Abstract:
Microdispensing of thick-film conductive paste has been demonstrated as a viable approach for manufacturing microwave planar transmission lines. However, the performance and upper frequency range of these lines is limited by the cross-sectional shape and electrical conductivity of the printed paste, as well as the achievable minimum feature size which is typically around . In this paper, a picosecond Nd:YAG laser is used to machine slots in a 20–25--thick layer of silver paste (Dupont CB028) that is microdispensed on a Rogers RT5870 substrate, producing coplanar waveguide (CPW) transmission lines with 16–-wide slots. It is shown that the laser solidifies an about 2--wide region of the edges of the slots, thus significantly increasing the effective conductivity of the film and improving the attenuation constant of the lines. The extracted attenuation constant at 20 GHz for laser machined CB028 is 0.74 dB/cm. CPW resonators and filters show that the effective conductivity is in the range from 10 to 30 MS/m, which represents a improvement when compared to the values obtained with the exclusive use of microdispensing. This paper demonstrates that a hybrid approach of additive manufacturing and laser machining enables the fabrication of higher frequency circuits (up to at least 40 GHz) with improved performance.
Autors: Eduardo A. Rojas-Nastrucci;Harvey Tsang;Paul I. Deffenbaugh;Ramiro A. Ramirez;Derar Hawatmeh;Anthony Ross;Kenneth Church;Thomas M. Weller;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3180 - 3187
Publisher: IEEE
 
» Characterization and Modeling of the Wind Turbine Radar Signature Using Turbine State Telemetry
Abstract:
Wind turbine observations and characterization efforts have treated the wind turbine as a noncooperative target. Similarly, suppression of the turbine’s radar signature has been considered without the aid of state information from the wind turbine under observation. In this paper, X-band radar observations of a utility-scale wind turbine, with detailed turbine state telemetry, are investigated. From scattering theory, the wind turbine’s physical structure has a deterministic radar cross section for a given observation geometry. Using the telemetry, the variation in the turbine’s signature is considered over a range of operating states. The deterministic nature of a turbine’s signature is demonstrated from radar observations, and a model is developed to isolate it. The turbine’s radar signature, as it relates to changes in the operating state, is discussed with the intent of enabling future suppression techniques.
Autors: Robert M. Beauchamp;V. Chandrasekar;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Sep 2017, volume: 55, issue:9, pages: 5134 - 5147
Publisher: IEEE
 
» Characterization and Optimization of a High-Efficiency AlGaAs-On-Insulator-Based Wavelength Converter for 64- and 256-QAM Signals
Abstract:
In this paper, we demonstrate wavelength conversion of advanced modulation formats such as 10-GBd 64-QAM and 256-QAM with high conversion efficiency over a 29-nm spectral window by using four-wave mixing in an AlGaAs-on-insulator (AlGaAsOI) nanowaveguide. A thorough characterization of the wavelength converter is reported, including the optimization of the AlGaAsOI nanowaveguide in terms of conversion efficiency and associated bandwidth and the analysis of the impact of the converter pump quality and power as well as the signal input power. The optimized converter enables generating idlers with optical signal-to-noise ratio (OSNR) above 30 dB over a 29-nm bandwidth leading to error-free conversion of 64-QAM and 256-QAM with OSNR penalty below 1.0 dB and 2.0 dB, respectively. The generated idlers exhibit an OSNR margin to the chosen forward error correction thresholds of >3 dB and >7 dB for 64-QAM and 256-QAM, respectively, that can be used for transmission after conversion.
Autors: Francesco Da Ros;Metodi P. Yankov;Edson P. da Silva;Minhao Pu;Luisa Ottaviano;Hao Hu;Elizaveta Semenova;Søren Forchhammer;Darko Zibar;Michael Galili;Kresten Yvind;Leif K. Oxenløwe;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:17, pages: 3750 - 3757
Publisher: IEEE
 
» Characterization of an NTD Double-Sided Silicon Strip Detector Employing a Pulsed Proton Microbeam
Abstract:
Monoenergetic pulsed proton beams at energies of 1 and 3 MeV per proton have been employed to characterize a segmented double-sided silicon strip detector. The detector is manufactured from a neutron transmutation doped silicon wafer and features a bulk resistivity of . Signals from both P-side and N-side strips have been digitized at 14 b, 100 MS/s. The beam was focused either in the middle of one strip or on the gap in between two strips. Energy resolution, charge collection time, and interstrip effects (charge sharing, charge losses, and inverted polarity pulses) have been investigated at different bias voltages and for particles entering either from the junction side or from the ohmic side.
Autors: J. A. Dueñas;G. Pasquali;L. Acosta;T. Parsani;F. Riccio;L. Carraresi;F. Taccetti;A. Castoldi;C. Guazzoni;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Sep 2017, volume: 64, issue:9, pages: 2551 - 2560
Publisher: IEEE
 
» Characterization of Kerfless Linear Arrays Based on PZT Thick Film
Abstract:
Multielement transducers enabling novel cost-effective fabrication of imaging arrays for medical applications have been presented earlier. Due to the favorable low lateral coupling of the screen-printed PZT, the elements can be defined by the top electrode pattern only, leading to a kerfless design with low crosstalk between the elements. The thick-film-based linear arrays have proved to be compatible with a commercial ultrasonic scanner and to support linear array beamforming as well as phased array beamforming. The main objective of the presented work is to investigate the performance of the devices at the transducer level by extensive measurements of the test structures. The arrays have been characterized by several different measurement techniques. First, electrical impedance measurements on several elements in air and liquid have been conducted in order to support material parameter identification using the Krimholtz–Leedom–Matthaei model. It has been found that electromechanical coupling is at the level of 35%. The arrays have also been characterized by a pulse-echo system. The measured sensitivity is around −60 dB, and the fractional bandwidth is close to 60%, while the center frequency is about 12 MHz over the whole array. Finally, laser interferometry measurements have been conducted indicating very good displacement level as well as pressure. The in-depth characterization of the array structure has given insight into the performance parameters for the array based on PZT thick film, and the obtained information will be used to optimize the key parameters for the next generation of cost-effective arrays based on piezoelectric thick film.
Autors: Tomasz Zawada;Louise Møller Bierregaard;Erling Ringgaard;Ruichao Xu;Michele Guizzetti;Franck Levassort;Dominique Certon;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Sep 2017, volume: 64, issue:9, pages: 1409 - 1416
Publisher: IEEE
 
» Characterization of the Photon Counting CHASE Jr., Chip Built in a 40-nm CMOS Process With a Charge Sharing Correction Algorithm Using a Collimated X-Ray Beam
Abstract:
This paper presents the detailed characterization of a single photon counting chip, named CHASE Jr., built in a CMOS 40-nm process, operating with synchrotron radiation. The chip utilizes an on-chip implementation of the C8P1 algorithm. The algorithm eliminates the charge sharing related uncertainties, namely, the dependence of the number of registered photons on the discriminator’s threshold, set for monochromatic irradiation, and errors in the assignment of an event to a certain pixel. The article presents a short description of the algorithm as well as the architecture of the CHASE Jr., chip. The analog and digital functionalities, allowing for proper operation of the C8P1 algorithm are described, namely, an offset correction for two discriminators independently, two-stage gain correction, and different operation modes of the digital blocks. The results of tests of the C8P1 operation are presented for the chip bump bonded to a silicon sensor and exposed to the 3.5--wide pencil beam of 8-keV photons of synchrotron radiation. It was studied how sensitive the algorithm performance is to the chip settings, as well as the uniformity of parameters of the analog front-end blocks. Presented results prove that the C8P1 algorithm enables counting all photons hitting the detector in between readout channels and retrieving the actual photon energy.
Autors: A. Krzyżanowska;G. W. Deptuch;P. Maj;P. Gryboś;R. Szczygieł;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Sep 2017, volume: 64, issue:9, pages: 2561 - 2568
Publisher: IEEE
 
» Chemical and Electrical Dynamics of Polyimide Film Damaged by Electron Radiation
Abstract:
The processes of electrical charge accumulation and dissipation in dielectric materials are critical to spacecraft construction and operational anomaly resolution. Electrical conductivity, and therefore surface potential, of radiation-damaged materials undergoes unpredicted changes while on orbit. The space environment causes fundamental modifications in the chemical structure of spacecraft materials by breaking intermolecular bonds and creating free radicals that act as space charge traps. Over time, free radicals react with each other and the material recovers. The rates of free radical formation and loss determine the dynamics of the conductivity of spacecraft materials. Lack of knowledge about dynamic aging is a major impediment to accurate modeling of spacecraft behavior over its mission life. This paper presents an investigation of the chemical and physical properties of polyimide (PI) films during and after irradiation with high-energy (90 keV) electrons. The constant voltage method was utilized to monitor material conductivity during the recovery process. To quantify the concentration of free radicals within the irradiated material, the electron paramagnetic resonance technique was used. Changes in the infrared (IR) absorption profile of irradiated materials during the recovery process were identified using the directional-hemispherical reflectance technique coupled with the Fourier transform IR spectroscopy. This physical/chemical collaboration allowed correlation of chemical changes in PI with the dynamic nature of spacecraft material aging.
Autors: Daniel P. Engelhart;Elena Plis;Sunita Humagain;Steven Greenbaum;Dale Ferguson;Russell Cooper;Ryan Hoffmann;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Sep 2017, volume: 45, issue:9, pages: 2573 - 2577
Publisher: IEEE
 
» Chemical Sensing Strategies for Real-Time Monitoring of Transformer Oil: A Review
Abstract:
Power transformers are a central component in the field of energy distribution and transmission. The early recognition of incipient faults in operating transformers is substantially cost effective by lessening impromptu blackouts. A standout amongst the most responsive and dependable strategies utilized for assessing the health of oil filled electrical equipment is dissolved gas analysis (DGA). Nowadays, there is an expanding requirement for better nonintrusive diagnostic and online monitoring tools to survey the internal state of the transformers. Chemical sensors are viewed as a key innovation for condition monitoring of transformer health, coordinating the non-invasiveness with typical sensor features, such as cost, usability, portability, and the integration with the data networks. Low-cost chemical sensors-based DGA techniques are expected to drastically augment the diagnostic abilities empowering the deployment on a broader range of oil filled power assets. The recent development involves both specific sensors designed to detect individual dissolved gas in transformer oil and non-specific sensors, operated in near ambient conditions, with the potential to be applied in a DGA system. In this paper, general background and operating guidelines of DGA are presented to address the origin of the gas formation, methods for their detection and the interpretation of the results by data analytics. The recent significant interest and advancements in chemical sensors to DGA applications are reviewed. Future research perspectives and challenges for the development of novel DGA chemical sensors are also discussed.
Autors: Chenhu Sun;Paul R. Ohodnicki;Emma M. Stewart;
Appeared in: IEEE Sensors Journal
Publication date: Sep 2017, volume: 17, issue:18, pages: 5786 - 5806
Publisher: IEEE
 
» Circuit and System Designs of Ultra-Low Power Sensor Nodes With Illustration in a Miniaturized GNSS Logger for Position Tracking: Part I—Analog Circuit Techniques
Abstract:
This paper, split into Parts I and II, reviews recent innovations in circuit design that have accelerated the miniaturization of sensor nodes. Design techniques for key building blocks, such as sensor interfaces, timing reference, data communication, energy harvesting, and power management are reviewed. In particular, Part I introduces analog circuit techniques and sensor interfaces for miniaturized sensor nodes. The energy budget of such system is highly restricted due to the small battery volume. Therefore, ultra-low power design techniques are critical enablers and are reviewed. Design techniques for compact monolithic integration are also discussed.
Autors: Taekwang Jang;Gyouho Kim;Benjamin Kempke;Michael B. Henry;Nikolaos Chiotellis;Carl Pfeiffer;Dongkwun Kim;Yejoong Kim;Zhiyoong Foo;Hyeongseok Kim;Anthony Grbic;Dennis Sylvester;Hun-Seok Kim;David D. Wentzloff;David Blaauw;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Sep 2017, volume: 64, issue:9, pages: 2237 - 2249
Publisher: IEEE
 
» Circular Patch Sensor Based on Distributed Fiber Optic Technology for Tensile and Bending Loads Identification
Abstract:
The design, manufacturing, and preliminary testing of a smart patch sensor named MonitoRing are herein presented. The sensor is conceived to identify amplitude and direction of structural loads by distributed strain profile detection along its circular geometry. The sensor is manufactured by using flexible glass/epoxy laminates hosting a single standard telecom fiber optic. The fiber optic is embedded according to three loops, different by radius and quote. The sensor is then externally bonded on a structural element and able to follow the deformations under tensile and bending loading condition. The optical Rayleigh backscattering technology provides an interrogation of strain with high spatial resolution all along the fiber path. The load and direction identification is hence, provided by comparing amplitude, phase and sign of deformation spectrum of each loop. Preliminary numerical and experimental result, are reported and analyzed for simple test cases.
Autors: Monica Ciminello;Paolo Bettini;Salvatore Ameduri;Antonio Concilio;
Appeared in: IEEE Sensors Journal
Publication date: Sep 2017, volume: 17, issue:18, pages: 5908 - 5914
Publisher: IEEE
 
» Classification of Error Correcting Codes and Estimation of Interleaver Parameters in a Noisy Transmission Environment
Abstract:
Channel encoder, which includes a forward error correcting (FEC) code followed by an interleaver, plays a vital role in improving the error performance of digital storage and communication systems. In most of the applications, the FEC code and interleaver parameters are known at the receiver to decode and de-interleave the information bits, respectively. But the blind/semi-blind estimation of code and interleaver parameters at the receiver will provide additional advantages in applications, such as adaptive modulation and coding, cognitive radio, non-cooperative systems, etc. The algorithms for the blind estimation of code parameters at the receiver had previously been proposed and investigated for known FEC codes. In this paper, we propose algorithms for the joint recognition of the type of FEC codes and interleaver parameters without knowing any information about the channel encoder. The proposed algorithm classify the incoming data symbols among block coded, convolutional coded, and uncoded symbols. Further, we suggest analytical and histogram approaches for setting the threshold value to perform code classification and parameter estimation. It is observed from the simulation results that the code classification and interleaver parameter estimation are performed successfully over erroneous channel conditions. The proposed histogram approach is more robust against the analytical approach for noisy transmission environment and system latency is one of the important challenges for the histogram approach to achieve better performance.
Autors: R. Swaminathan;A. S. Madhukumar;
Appeared in: IEEE Transactions on Broadcasting
Publication date: Sep 2017, volume: 63, issue:3, pages: 463 - 478
Publisher: IEEE
 
» Clock Data Compensation Aware Digital Circuits Design for Voltage Margin Reduction
Abstract:
Tolerating timing error due to power supply noise (PSN) in digital circuits can be done with adding voltage margins. Conservative addition of voltage margins leads wastes of power reducing the battery life in Internet of Things (IoT) devices. This paper aims to provide guidelines to avoid over-design due to PSN especially for the low-cost IoT devices. To this end, we first present an accurate time-domain behavioral model of timing slack variation due to PSN accounting for the clock-data compensation. The accuracy of the model is verified against SPICE for complex designs, including AES engine and LEON3 processor. To prove the effectiveness of our model for reducing voltage margin, we utilize our model in standard VLSI design flow for various examples, such as timing slack versus noise frequency analysis, determining optimal value of an on-die capacitor, analyzing the effects of time borrowing technique, and PVT variation simulations. The analysis shows that the model helps reduce pessimism in estimated timing slack.
Autors: Taesik Na;Jong Hwan Ko;Saibal Mukhopadhyay;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Sep 2017, volume: 64, issue:9, pages: 2401 - 2413
Publisher: IEEE
 
» Cluster Head Enhanced Election Type-2 Fuzzy Algorithm for Wireless Sensor Networks
Abstract:
This approach presents a fully distributed clustering solution for wireless sensor networks. It relies on the results of an interval type-2 fuzzy logic system that gives each node the chance to be a cluster head. Taking into account the limited computational resources of the sensors, this inference system has been carefully adapted to be run in each node through a sampling process of the entire solution space of the fuzzy system. The input variables of the system are obtained from the information that each node derives from its performance metrics and those related to its neighbors. The acquisition of these last data does not incur in any additional control packets. The results obtained show a significant improvement in the network lifetime when compared with other recent approaches. This improvement takes place even when contrasting with centralized methods.
Autors: J. C. Cuevas-Martinez;A. J. Yuste-Delgado;A. Triviño-Cabrera;
Appeared in: IEEE Communications Letters
Publication date: Sep 2017, volume: 21, issue:9, pages: 2069 - 2072
Publisher: IEEE
 
» Clustering with Hypergraphs: The Case for Large Hyperedges
Abstract:
The extension of conventional clustering to hypergraph clustering, which involves higher order similarities instead of pairwise similarities, is increasingly gaining attention in computer vision. This is due to the fact that many clustering problems require an affinity measure that must involve a subset of data of size more than two. In the context of hypergraph clustering, the calculation of such higher order similarities on data subsets gives rise to hyperedges. Almost all previous work on hypergraph clustering in computer vision, however, has considered the smallest possible hyperedge size, due to a lack of study into the potential benefits of large hyperedges and effective algorithms to generate them. In this paper, we show that large hyperedges are better from both a theoretical and an empirical standpoint. We then propose a novel guided sampling strategy for large hyperedges, based on the concept of random cluster models. Our method can generate large pure hyperedges that significantly improve grouping accuracy without exponential increases in sampling costs. We demonstrate the efficacy of our technique on various higher-order grouping problems. In particular, we show that our approach improves the accuracy and efficiency of motion segmentation from dense, long-term, trajectories.
Autors: Pulak Purkait;Tat-Jun Chin;Alireza Sadri;David Suter;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Sep 2017, volume: 39, issue:9, pages: 1697 - 1711
Publisher: IEEE
 
» CMOS Compatible Electrostatically Formed Nanowire Transistor for Efficient Sensing of Temperature
Abstract:
A novel electrostatically formed nano-wire (EFN) transistor for temperature sensing is presented. The device is a silicon-on-insulator multigate field-effect transistor, in which a nanowire-shaped conducting channel vertical position and area are controlled by the bias applied to the back gate, and two junction-side gates. Our measurements depict temperature sensitivity of 7.7%/K for EFN transistors which is among the best reported values for semiconductor temperature sensing devices TMOS and FET’s. Optimal operational voltage biases and currents for the EFN transistor regimes are evaluated from measurements and analyzed using three dimensional (3D) electrostatic device simulations and developed analytical model.
Autors: Klimentiy Shimanovich;Tom Coen;Yonatan Vaknin;Alex Henning;Joseph Hayon;Yakov Roizin;Yossi Rosenwaks;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3836 - 3840
Publisher: IEEE
 
» Coastal Sea Ice Detection Using Ground-Based GNSS-R
Abstract:
Determination of sea ice extent is important both for climate modeling and transportation planning. Detection and monitoring of ice are often done by synthetic aperture radar imagery, but mostly without any ground truth. For the latter purpose, robust and continuously operating sensors are required. We demonstrate that signals recorded by ground-based Global Navigation Satellite System (GNSS) receivers can detect coastal ice coverage on nearby water surfaces. Beside a description of the retrieval approach, we discuss why GNSS reflectometry is sensitive to the presence of sea ice. It is shown that during winter seasons with freezing periods, the GNSS-R analysis of data recorded with a coastal GNSS installation clearly shows the occurrence of ice in the bay where this installation is located. Thus, coastal GNSS installations could be promising sources of ground truth for sea ice extent measurements.
Autors: Joakim Strandberg;Thomas Hobiger;Rüdiger Haas;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Sep 2017, volume: 14, issue:9, pages: 1552 - 1556
Publisher: IEEE
 
» Cognition-Enabled Robot Manipulation in Human Environments: Requirements, Recent Work, and Open Problems
Abstract:
Service robots are expected to play an important role in our daily lives as our companions in home and work environments in the near future. An important requirement for fulfilling this expectation is to equip robots with skills to perform everyday manipulation tasks, the success of which is crucial for most home chores, such as cooking, cleaning, and shopping. Robots have been used successfully for manipulation tasks in wellstructured and controlled factory environments for decades. Designing skills for robots working in uncontrolled human environments raises many potential challenges in various subdisciplines, such as computer vision, automated planning, and human-robot interaction. In spite of the recent progress in these fields, there are still challenges to tackle. This article outlines problems in different research areas related to mobile manipulation from the cognitive perspective, reviews recently published works and the state-of-the-art approaches to address these problems, and discusses open problems to be solved to realize robot assistants that can be used in manipulation tasks in unstructured human environments.
Autors: Mustafa Ersen;Erhan Oztop;Sanem Sariel;
Appeared in: IEEE Robotics & Automation Magazine
Publication date: Sep 2017, volume: 24, issue:3, pages: 108 - 122
Publisher: IEEE
 
» Cognitively Adjusting Imprecise User Preferences for Service Selection
Abstract:
Most state-of-the-art service selection approaches assume user preferences can be provided by the target user with sufficient precision and ignore historical service usage data for all users. It is desirable for ordinary users to possess a new service selection approach that can recommend satisfactory services to them even when their service selection preferences are specified imprecisely in terms of vagueness, inaccuracy, and incompleteness. This paper proposes a novel service selection approach that resolves the imprecise characteristics of user preferences and can recommend satisfactory services for users with varying cognitive levels in terms of service experience. The proposed service selection approach is comprised of four major tasks: 1) employ user-friendly linguistic variables to collect apparent user preferences (AUP) and convert the linguistic variables to standardized fuzzy weights as AUP weights; 2) evaluate all users’ respective cognitive levels for the target service type and obtain the cognitive level threshold for that type of services; 3) adjust the AUP weights based on the calculated cognitive levels and the threshold, and supplement the potential user preferences weights; and 4) prioritize candidate services per a user satisfaction maximization objective. In-depth comparative experimental evaluations were performed using two real-world datasets. The results show that our service selection model outperforms three other representative ones and could provide a stable and reliable selection of services for the users with low service cognitive levels.
Autors: Lingyan Zhang;Shangguang Wang;Raymond K. Wong;Fangchun Yang;Rong N. Chang;
Appeared in: IEEE Transactions on Network and Service Management
Publication date: Sep 2017, volume: 14, issue:3, pages: 717 - 729
Publisher: IEEE
 
» Collaborators & Friends: The General Meeting Brings Us Together [Leader's Corner]
Abstract:
Presents highlights of the PES society 2017 General Meeting.
Autors: Jessica Bian;
Appeared in: IEEE Power and Energy Magazine
Publication date: Sep 2017, volume: 15, issue:5, pages: 10 - 10
Publisher: IEEE
 
» Comb-Assisted Cyclostationary Analysis of Wideband RF Signals
Abstract:
Signals arising in nearly all disciplines, including telecommunications, mechanics, biology, astronomy, and nature are generally modulated, carrying corresponding signatures in both the temporal and spectral domains. This fact was long recognized by cyclostationary and cumulant analysis, providing qualitatively better means to separate stochastic from deterministically modulated radiation. In contrast to simple spectral analysis, the cyclostationary technique provides a high level of spectral discrimination, allowing for considerable signal selectivity even in the presence of high levels of background noise and interference. When performed with sufficient resolution, cyclostationary analysis also provides the ability for signal analysis and classification. Unfortunately, these advantages come at a cost of large computational complexity posing fundamental detection challenges. In the case of modern ultrawideband signals, the requirements for persistent cyclostationary analysis are considerably beyond the processing complexity of conventional electronics. Recognizing this limit, we report a new photonically assisted cyclostationary analyzer that eliminates the need for high-bandwidth digitization and real-time Fourier processors. The new receiver relies on mutually coherent frequency combs used to generate a Fourier representation of the received signal in a computation-free manner. With the advent of practical, cavity-free optical frequency combs, the complexity for cyclostationary analysis can be greatly reduced, paving a path toward persistent wideband cyclostationary analysis in an ultrawideband operating regime.
Autors: Daniel J. Esman;Vahid Ataie;Bill Ping-Piu Kuo;Eduardo Temprana;Nikola Alic;Stojan Radic;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:17, pages: 3705 - 3712
Publisher: IEEE
 
» Combined Active and Reactive Power Control of Wind Farms Based on Model Predictive Control
Abstract:
This paper proposes a combined wind farm controller based on Model Predictive Control (MPC). Compared with the conventional decoupled active and reactive power controls, the proposed control scheme considers the significant impact of active power on voltage variations due to the low ratio of wind farm collector systems. The voltage control is improved. Besides, by coordination of active and reactive powers, the Var capacity is optimized to prevent potential failures due to Var shortage, especially when the wind farm operates close to its full load. An analytical method is used to calculate the sensitivity coefficients to improve the computation efficiency and overcome the convergence problem. Two control modes are designed for both normal and emergency conditions. A wind farm with 20 wind turbines was used to verify the proposed combined control scheme.
Autors: Haoran Zhao;Qiuwei Wu;Jianhui Wang;Zhaoxi Liu;Mohammad Shahidehpour;Yusheng Xue;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 1177 - 1187
Publisher: IEEE
 
» Combined Current Sensing Method for the Three-Phase Quasi-Z-Source Inverter
Abstract:
The impedance-source network converter, utilizing a unique LC network and previously forbidden shoot-through states, provides the ability to buck and boost the input voltage in a single stage. However, the inrush shoot-through current (STC) in startup or transient process might cause undesired current stresses on converter devices. This paper focuses on the STC sensing for an effective inrush current limitation by the combined current sensing technique in the quasi-Z-source inverter. STC and phase currents for the inverter control strategy are obtained simultaneously. No extra hardware is needed and the effects of current sensor bandwidth and duty cycle on the sensing accuracy are analyzed mathematically. The voltage spike gets avoided by integrating the stray inductance into the impedance network. Finally, an STC control loop based on proposed method are embedded in the field-oriented control strategy. The inrush STC and the device current stress in the transient process get suppressed. Simulation and experimental results from a quasi-Z-source inverter validate the feasibility of the proposed methods.
Autors: Sideng Hu;Zipeng Liang;Xiangning He;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7152 - 7160
Publisher: IEEE
 
» Combined Redundancy Allocation and Maintenance Planning Using a Two-Stage Stochastic Programming Model for Multiple Component Systems
Abstract:
A new modeling approach is presented to optimally and simultaneously design the configuration of a multicomponent system and determine a maintenance plan with uncertain future stress exposure. Traditionally, analytical models for system design and maintenance planning are applied sequentially, but this new model provides an integrated approach to make decisions considering the lifecycle cost of the system. Specifically considering the influence of uncertain future usage stresses on component and system reliability, the integrated redundancy allocation and maintenance planning problem is formulated as a two-stage stochastic programming model with recourse. In this model, the system is exposed to uncertain usage scenarios with their associated probabilities of occurrence or likelihood. The decision variables for the first stage are the selection of component types and the number of components to be used in the system, and these variables are modeled before the uncertainty is revealed. The second-stage variables, involving a recourse function, are the preventive maintenance plan, which defines optimal maintenance times for planned replacement of components under distinct usage scenarios. Numerical examples and sensitivity analysis on series–parallel systems demonstrate applications of the proposed model and provide further insights. The comparisons of the proposed integrated approach to traditional sequential method show advantages of the proposed model in cost saving.
Autors: Xiaoqiang Bei;Nida Chatwattanasiri;David W. Coit;Xiaoyan Zhu;
Appeared in: IEEE Transactions on Reliability
Publication date: Sep 2017, volume: 66, issue:3, pages: 950 - 962
Publisher: IEEE
 
» Combining Improved Gray-Level Co-Occurrence Matrix With High Density Grid for Myoelectric Control Robustness to Electrode Shift
Abstract:
Pattern recognition-based myoelectric control is greatly influenced by electrode shift, which is inevitable during prosthesis donning and doffing. This study used gray-level co-occurrence matrix (GLCM) to represent the spatial distribution among high density (HD) electrodes and improved its calculation based on the using condition of myoelectric system, proposing a new feature, iGLCM, to improve the robustness of the system. The effects of its two parameters, quantization level and input data, were first evaluated and it was found that improved discrete Fourier transform (iDFT) performed better than the other three (time-domain, autoregressive, root mean square) as the input data of iGLCM, and increasing quantization level did not significantly decrease the error rate of iGLCM when it was above 8. The performance of iGLCM with iDFT as input data and 8 as quantization level was subsequently compared with previous robust approaches (time domain autoregressive, variogram, common spatial pattern and optimal less channel configuration) and its input data, iDFT. It was showed that iGLCM achieved comparable classification accuracy without shift, and significantly decreased the sensitivity to electrode shift with 1 cm (p < 0.05). More importantly, it could reduce the perpendicular shift distance to half interelectrode distance with the electrodes worn as a band around the circumference of the forearm. Combined with the small interelectrode distance of HD electrodes, it provided a way to control the effect of perpendicular shifts fundamentally, which were the main source of performance degradation. Finally, the analysis of feature space revealed that the robustness was improved by discarding information sensitivity to shift and keeping as much as useful information. This study highlighted the importance of HD electrodes in robust myoelectric control, and the outcome would help the design of robust control system based on pattern recognition and promote it- application in real-world condition.
Autors: Jiayuan He;Xiangyang Zhu;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Sep 2017, volume: 25, issue:9, pages: 1539 - 1548
Publisher: IEEE
 
» Combustion Diagnostics by Calibrated Radiation Sensing and Spectral Estimation
Abstract:
Optimization of combustion processes holds the promise of maximizing energy efficiency, at the same time lowering fuel consumption and residual gases emissions. In this context, the current common operation setting in combustion processes could be improved by the introduction of passive optical sensors, which can be located close the flame, thus eliminating the inherent transport delay in current setups that only infer the combustion quality by measuring residual gases emissions. However, there is a tradeoff for flame detection between spatial-spectral resolutions, depending on the optical sensor scheme. In this paper, we present the fundamentals to avoid this constraint, obtaining a combined high spectral and spatial resolution measurement suitable for combustion diagnostics and control. The core of this proposal is to use the flame images from a low-spectral resolution charge-coupled device camera, combined with a spectral recovery method. This method is based on the off-line samples measured on the continuous component of flame spectra, providing a set of vector basis to estimate a calibrated flame spectra at each pixel. The results of the spectral recovery process verify the suitability of the method in terms of goodness-of-fit coefficient and root mean square error metrics, enabling hyper-spectral measurements based on the combination of different optical sensors. Then, continuous estimated spectra along the flame are used to calculate the energy transfer released by radiation, useful for combustion diagnostics.
Autors: Hugo O. Garcés;Luis E. Arias;Alejandro J. Rojas;Juan Cuevas;Andrés Fuentes;
Appeared in: IEEE Sensors Journal
Publication date: Sep 2017, volume: 17, issue:18, pages: 5871 - 5879
Publisher: IEEE
 
» Comment on “Optimal Precoding for a QoS Optimization Problem in Two-User MISO-NOMA Downlink”
Abstract:
Recently, optimum non-orthogonal multiple access (NOMA) precoding for a two-user multiple-input single-output (MISO) downlink has been proposed by Chen et al. Reference [1, Proposition 1] demonstrates that strong duality holds for the MISO-NOMA precoding optimization problem. Hence, the proposed preocoding algorithm is not only locally optimal, but also globally optimal. However, the proof of this proposition is flawed. In this regard, we provide a corrected proof in this comment.
Autors: Zhiyong Chen;Zhiguo Ding;Peng Xu;Xuchu Dai;Jie Xu;Derrick Wing Kwan Ng;
Appeared in: IEEE Communications Letters
Publication date: Sep 2017, volume: 21, issue:9, pages: 2109 - 2111
Publisher: IEEE
 
» Comments on “Impact of Load Frequency Dependence on the NDZ and Performance of the SFS Islanding Detection Method”
Abstract:
We read with interest an article by Zeineldin and Salama, published in the IEEE Transactions on Industrial Electronics (vol. 58, no. 1, pp. 139–146, Jan. 2011) and tried to reproduce the results of this article for the needs of our own research. Unfortunately, we were led to think that the load model equations used by the authors contained an inconspicuous but significant mathematical error, leading to erroneous results and conclusion. This letter brings corrections to some figures and their analysis as well as the paper conclusion. The new results show that the load's frequency dependence has actually no significant impact on the NDZ of the SFS method.
Autors: Olivier Arguence;Bertrand Raison;Florent Cadoux;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7277 - 7279
Publisher: IEEE
 
» Comments on “Miniaturization of a 90° Hybrid Coupler With Improved Bandwidth Performance”
Abstract:
In the above paper [1], the authors proposed a quadrature phase difference equal power division-coupled line coupler. However, the design equations presented in [1, eq. (8)] seem to be erroneous, and the bound of electrical lengths is incorrect. Here, a correct set of design equations and electrical length bound have been provided based on [2, eq. (89)].
Autors: Rakesh Sinha;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Sep 2017, volume: 27, issue:9, pages: 857 - 858
Publisher: IEEE
 
» Commercial Off-the-Shelf Digital Cameras on Unmanned Aerial Vehicles for Multitemporal Monitoring of Vegetation Reflectance and NDVI
Abstract:
This paper demonstrates the ability to generate quantitative remote sensing products by means of an unmanned aerial vehicle (UAV) equipped with one unaltered and one near infrared-modified commercial off-the-shelf (COTS) camera. Radiometrically calibrated orthomosaics were generated for 17 dates, from which digital numbers were corrected to surface reflectance and to normalized difference vegetation index (NDVI). Validation against ground measurements showed that 84%–90% of the variation in the ground reflectance and 95%–96% of the variation in the ground NDVI could be explained by the UAV-retrieved reflectance and NDVI, respectively. Comparisons against Landsat 8 data showed relationships of for reflectance and for NDVI. It was not possible to generate a fully consistent time series of reflectance, due to variable illumination conditions during acquisition on some dates. However, the calculation of NDVI resulted in a more stable UAV time series, which was consistent with a Landsat series of NDVI extracted over a deciduous and evergreen woodland. The results confirm that COTS cameras, following calibration, can yield accurate reflectance estimates (under stable within-flight illumination conditions), and that consistent NDVI time series can be acquired in very variable illumination conditions. Such methods have significant potential in providing flexible, low-cost approaches to vegetation monitoring at fine spatial resolution and for user-controlled revisit periods.
Autors: Elias F. Berra;Rachel Gaulton;Stuart Barr;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Sep 2017, volume: 55, issue:9, pages: 4878 - 4886
Publisher: IEEE
 
» Common-Mode EMI Noise Modeling and Reduction With Balance Technique for Three-Level Neutral Point Clamped Topology
Abstract:
This paper develops a common-mode (CM) electromagnetic interference noise model for a three-level neutral point clamped topology. Compared with existing modeling techniques with only one CM noise source, two extra important CM noise sources and their characteristics are identified and derived for an accurate CM noise model. The impedances of CM noise path are also extracted. Based on the developed CM noise model, the CM noise spectrum can be well predicted. The effect of CM noise paths on CM noise is discussed based on two different LCL filters. A CM noise reduction technique with a balance bridge at a large impedance ratio is proposed based on the developed model. The technique can be easily implemented at low cost. Both simulations and experiments validate the developed theory and technique.
Autors: Huan Zhang;Le Yang;Shuo Wang;Joonas Puukko;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7563 - 7573
Publisher: IEEE
 
» Communicating With Employees: Resisting the Stereotypes of Generational Cohorts in the Workplace
Abstract:
Introduction: Stereotypes about generational cohorts have been spread widely among current literature; this study challenges those stereotypes and provides a simple method for managers to learn how to effectively communicate with, motivate, and retain employees, no matter what cohort they belong to. Research questions: (1) Do people in a particular generational cohort behave according to the stereotypes assigned to their cohort? (2) Do people in a particular generation believe that the stereotypes assigned to their generation are accurate? Literature review: Current literature promulgates generational stereotypes and encourages managers to learn about the differences of each cohort so that they can tailor their communication to each cohort. Knowing the differences allegedly provides managers of technical communication teams or any team with more effective strategies to communicate with, motivate, and retain members of each cohort. Much of the literature examined was not based on rigorous research, and some that was rigorous and empirical claims there are more similarities than differences among the cohorts. Methodology: The findings from this study are based on answers to surveys from 107 participants and semistructured interviews with eight of those participants who were employees at a software company or were students or employees at a local university. The findings challenge the stereotypes found in the current literature, specifically concerning longevity in a job and workplace compliance. Conclusions, limitations, and future research: Managers need to learn more about individual employees rather than relying on stereotypes of generational cohorts when communicating with employees. Learning about individuals is simple and can foster more effective communication, which will enhance employees' job satisfaction and engagement, and ultimately employee retention. As the research reported in this study shows, these are crucial variables to consider about- a person's tenure in a position and workplace compliance behavior but are not included by most when studying generational cohorts. Further research could help us learn how managers can best develop employees and recognize and reward employees' workplace achievements.
Autors: Rhonda Stanton;
Appeared in: IEEE Transactions on Professional Communication
Publication date: Sep 2017, volume: 60, issue:3, pages: 256 - 272
Publisher: IEEE
 
» Compact Bandpass Filter With High Selectivity Using Quarter-Mode Substrate Integrated Waveguide and Coplanar Waveguide
Abstract:
This letter presents a bandpass filter (BPF) based on a hybrid structure of quarter-mode substrate integrated waveguide (QMSIW) and coplanar waveguide (CPW). By incorporating two CPW resonators into two QMSIW resonators, the proposed filter obtains a high selectivity as the coupling between two CPW resonators is electric coupling, which helps to generate two transmission zeros. It also achieves compact layout as the embedded CPW resonators do not occupy extra area. In order to verify the design, a BPF with a center frequency of 8.7 GHz is fabricated and measured. The measured results show good agreement with the simulation results.
Autors: Zhaosheng He;Chang Jiang You;Supeng Leng;Xiang Li;Yong-Mao Huang;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Sep 2017, volume: 27, issue:9, pages: 809 - 811
Publisher: IEEE
 
» Compact Broadband Circularly Polarized Antenna With Parasitic Patches
Abstract:
A broadband circularly polarized (CP) antenna with compact size is proposed. The antenna is composed of a loop feeding structure which provides sequential phase, four driven patches, and four parasitic patches. The driven patches, which are capacitively coupled by the feeding loop, generate one CP mode due to the sequentially rotated structure and four parasitic patches are introduced to produce additional CP mode. By combining with the CP mode of the feeding loop, the axial ratio (AR) bandwidth is greatly broadened. An antenna prototype is fabricated to validate the simulated results. Experimental results show that the antenna achieves a broad impedance bandwidth of 19.5% from 5.13 to 6.24 GHz and a 3-dB AR bandwidth of 12.9% (5.38–6.12 GHz). In addition, the proposed antenna also has a flat gain within the operating frequency band and a compact size of at 5.5 GHz.
Autors: Kang Ding;Cheng Gao;Dexin Qu;Qin Yin;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Sep 2017, volume: 65, issue:9, pages: 4854 - 4857
Publisher: IEEE
 
» Compact Constant Weight Coding Engines for the Code-Based Cryptography
Abstract:
We present here a more memory efficient method for encoding binary information into words of prescribed length and weight. Existing solutions either require complicated float point arithmetic or additional memory overhead, making it a challenge for resource constrained computing environment. The solution we propose here solves these problems yet obtains better coding efficiency by a memory efficient approximation of the critical intermediate value in constant weight coding. For the time being, the design presented in this brief is the most compact one for any code-based encryption schemes.
Autors: Jingwei Hu;Ray C. C. Cheung;Tim Güneysu;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Sep 2017, volume: 64, issue:9, pages: 1092 - 1096
Publisher: IEEE
 
» Compact Dual-Band Dual-Polarized Interleaved Two-Beam Array With Stable Radiation Pattern Based on Filtering Elements
Abstract:
This paper presents a compact dual-band antenna array with dual polarizations and two beams for base-station applications. It consists of two subarrays operating at 3G (1710–2170 MHz) and long term evolution (2490–2690 MHz) bands. For size miniaturization, the elements of the two subarrays are interleaved with each other. The mutual coupling between the elements operating at different bands is suppressed by using filtering antennas with out-of-band radiation suppression. And the spacing between them can be decreased, resulting in array miniaturization. To obtain stable two-beam radiation patterns within the two operating bands, the beam-forming networks with little magnitude and phase imbalances are specially designed for each band. For demonstration, the proposed array is implemented. In the measurement, the array exhibits stable 10-dB beamwidth around 120° in the azimuth plane within the two entire bands. As a result, the two-beam radiation patterns satisfy the coverage requirement of 120° in the azimuth plane for base-station applications. Additionally, 16.4 dBi/15.5 dBi peak gains and around −10 dB cross levels at the junction of two beams are achieved within the two operating bands. Compared with typical industrial products, the proposed array features both compact size and stable radiation patterns. Moreover, the proposed method can easily be extended to multibeam base-station array designs.
Autors: Xiu-Yin Zhang;Di Xue;Liang-Hua Ye;Yong-Mei Pan;Yao Zhang;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Sep 2017, volume: 65, issue:9, pages: 4566 - 4575
Publisher: IEEE
 
» Compact Millimeter-Wave CMOS Wideband Three-Transmission-Zeros Bandstop Filter Using a Single Coupled-Line Unit
Abstract:
This brief presents the design and implementation of millimeter-wave ultra-wide bandstop filter (BSF) using a standard 0.18- CMOS technology. The BSF configuration consists of a single coupled-line resonator shorted at the middle, which operates as not only a resonant element but also an open stub. The BSF realizes three transmission zeros in the stopband that results in sharp skirt selectivity. The overall width of the filter is less than the width of a 50- line and occupies a compact area of , where is the guided wavelength at 60 GHz. Explicit design equations are derived analytically using lossless transmission model. A prototype wideband BSF with a 3-dB bandwidth of 110% at 60 GHz is realized on a thin-film microstrip structure. The impact of several CMOS process parameters on the designed filter is also examined.
Autors: Venkata Narayana Rao Vanukuru;Vamsi Krishna Velidi;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Sep 2017, volume: 64, issue:9, pages: 1022 - 1026
Publisher: IEEE
 
» Compact Modeling Source-to-Drain Tunneling in Sub-10-nm GAA FinFET With Industry Standard Model
Abstract:
We present a compact model for source-to-drain tunneling current in sub-10-nm gate-all-around FinFET, where tunneling current becomes nonnegligible. Wentzel–Kramers–Brillouin method with a quadratic potential energy profile is used to analytically capture the dependence on biases in the tunneling probability expression and simplify the equation. The calculated tunneling probability increases with smaller effective mass and with increasing bias. We at first use the Gaussian quadrature method to integrate Landauer’s equation for tunneling current computation without further approximations. To boost simulation speed, some approximations are made. The simplified equation shows a good accuracy and has more flexibility for compact model purpose. The model is implemented into industry standard Berkeley Short-channel IGFET Model-common multi-gate model for future technology node, and is validated by the full-band atomistic quantum transport simulation data.
Autors: Yen-Kai Lin;Juan Pablo Duarte;Pragya Kushwaha;Harshit Agarwal;Huan-Lin Chang;Angada Sachid;Sayeef Salahuddin;Chenming Hu;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3576 - 3581
Publisher: IEEE
 
» Compact Wideband Phase Shifter Using Microstrip Self-Coupled Line and Broadside-Coupled Microstrip/CPW for Multiphase Feed-Network
Abstract:
In this letter, a compact wideband phase shifter using a microstrip self-coupled line and a broadside-coupled microstrip/CPW (BCMC) structure is proposed for multiphase feed-network. With a uniform phase reference, such a phase shifter can achieve multiphase responses by adjusting instinct self- and broadside couplings for constant phase shifts within a wideband. Then, with the combination of proposed phase shifters and a microstrip Wilkinson power divider, a multiphase feed-network can be implemented. To verify the mechanisms mentioned earlier, a wideband feed-network is fabricated with measured multiphase responses (i.e., 0°, 5.625°, 11.25°, 22.5°, 45°, 90°, and 180°) and maximum insertion loss of 1.57 dB from 1.7 to 2.3 GHz.
Autors: Jie Zhou;Huizhen Jenny Qian;Xun Luo;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Sep 2017, volume: 27, issue:9, pages: 791 - 793
Publisher: IEEE
 
» Comparative Analyses of Bi-Tapered Fiber Mach–Zehnder Interferometer for Refractive Index Sensing
Abstract:
In this paper, a high sensitivity of splicing regions tapered photonic crystal fiber (PCF) Mach–Zehnder interfero- metric refractive index (RI) sensor is described and experimentally demonstrated. Compared with cascaded bi-tapered single-mode fiber (SMF) Mach–Zehnder interferometer (MZI), the splicing regions tapered PCF MZI have higher sensitivity for the reason that it can better control and excite higher order modes, and has lower energy loss than cascaded bi-tapered PCF in the process of light transmission. Experimental results indicate that the RI sensitivity of splicing regions tapered PCF MZI could be up to 240.16 nm/RIU which is almost four times of cascaded bi-tapered SMF in the RI range of 1.3333–1.3792. Meanwhile, this splicing region tapered PCF Mach–Zehnder interferometric RI sensor has the advantages of higher RI sensitivity, good linearity, simple in making, and more potential practical value in the measurement of external RI.
Autors: Qi Wang;Bo-Tao Wang;Ling-Xin Kong;Yong Zhao;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Sep 2017, volume: 66, issue:9, pages: 2483 - 2489
Publisher: IEEE
 
» Comparative Analysis of Partitioned Stator Flux Reversal PM Machine and Magnetically Geared Machine Operating in Stator-PM and Rotor-PM Modes
Abstract:
In this paper, the partitioned stator flux reversal permanent magnet (PM) (PS-FRPM) machine and the conventional magnetically geared (MG) machine operating in both stator-PM (SPM) and rotor-PM (RPM) modes are comparatively analyzed in terms of electromagnetic performance to provide design guides for an MG machine regarding an SPM- or RPM-type machine and a higher or lower gear ratio machine. It is found that an SPM-type machine is recommended since both PS-FRPM and MG machines operating in SPM modes have a higher phase back-EMF and hence torque than their RPM counterparts, respectively, as a result of a similar phase flux linkage but a higher electric frequency since the iron piece number is larger than the PM pole-pair number. Moreover, a smaller gear ratio machine is preferred from the perspective of a higher power factor and hence a lower inverter power rating, as the conventional MG machines with higher gear ratios suffer from larger flux-leakage, higher synchronous reactance and hence lower power factors, as well as higher iron losses, than the PS-FRPM machines. However, higher gear ratio machines feature lower cogging torques and torque ripples due to the smaller difference between the PM pole-pair number and iron piece number. Both prototypes of PS-FRPM machine operating in SPM mode and MG machine operating in RPM mode are built and tested to verify the finite element predicted results.
Autors: Zhongze Wu;Z. Q. Zhu;Hanlin Zhan;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 903 - 917
Publisher: IEEE
 
» Comparative Study of RESURF Si/SiC LDMOSFETs for High-Temperature Applications Using TCAD Modeling
Abstract:
This paper analyses the effect of employing an Si on semi-insulating SiC (Si/SiC) device architecture for the implementation of 600-V LDMOSFETs using junction isolation and dielectric isolation reduced surface electric field technologies for high-temperature operations up to 300 °C. Simulations are carried out for two Si/SiC transistors designed with either PN or silicon-on-insulator (SOI) and their equivalent structures employing bulk-Si or SOI substrates. Through comparisons, it is shown that the Si/SiC devices have the potential to operate with an off-state leakage current as low as the SOI device. However, the low-side resistance of the SOI LDMOSFET is smaller in value and less sensitive to temperature, outperforming both Si/SiC devices. Conversely, under high-side configurations, the Si/SiC transistors have resistances lower than that of the SOI at high substrate bias, and invariablewith substrate potential up to −200 V, which behaves similar to the bulk-Si LDMOS at 300 K. Furthermore, the thermal advantage of the Si/SiC over other structures is demonstrated by using a rectanglepower pulse setup in TechnologyComputer-Aided Design simulations.
Autors: C. W. Chan;F. Li;A. Sanchez;P. A. Mawby;P. M. Gammon;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3713 - 3718
Publisher: IEEE
 
» Comparison for 1/ ${f}$ Noise Characteristics of AlGaN/GaN FinFET and Planar MISHFET
Abstract:
DC and 1/ noise performances of the AlGaN/GaN fin-shaped field-effect transistor (FinFET) with fin width of 50 nm were analyzed. The FinFET exhibited approximately six times larger normalized drain current and transconductance, compared to those of the AlGaN/GaN planar metal-insulator-semiconductor heterostructure field-effect-transistor (MISHFET) fabricated on the same wafer. It was also observed that the FinFET exhibited improved noise performance with lower noise magnitude of /Hz when compared to the value of /Hz for the planar MISHFET. An intensive analysis indicated that both devices follow the carrier number fluctuation model, but the FinFET suffers much less charge trapping effect compared to the MISHFET (two orders lower charge trapping was observed). Moreover, the FinFET did not exhibit the Lorentz-like components, which explains that the depleted fin structure effectively prevents the carriers from being trapped into the underlying thick GaN buffer layer. On the other hand, the slope of the noise is 2 irrespective of drain voltage and apparently showed the Lorentz-like components, especially at high drain voltage in MISHFET device. This explains that the carrier trapping/detrapping between the 2-D electron gas channel and the GaN buffer layer is significant in MISHFET.
Autors: Sindhuri Vodapally;Christoforos G. Theodorou;Youngho Bae;Gérard Ghibaudo;Sorin Cristoloveanu;Ki-Sik Im;Jung-Hee Lee;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3634 - 3638
Publisher: IEEE
 
» Comparison of Collision-Free and Contention-Based Radio Access Protocols for the Internet of Things
Abstract:
The fifth-generation (5G) cellular networks will face the challenge of integrating the traditional broadband services with the Internet of Things (IoT), which is characterized by sporadic uplink transmissions of small data packets. Indeed, the access procedure of the previous generation cellular network (4G) is not able to support IoT traffic efficiently, because it requires a large amount of signaling for the connection setup before the actual data transmission. In this context, we introduce two innovative radio access protocols for sporadic transmissions of small data packets, which are suitable for 5G networks, because they provide a resource-efficient packet delivery exploiting a connectionless approach. The core of this paper resides in the derivation of an analytical framework to evaluate the performance of all the aforementioned protocols. The final goal is the comparison between 4G and 5G radio access solutions employing both our analytical framework and computer simulations. The performance evaluation results show the benefits of the protocols envisioned for 5G in terms of signaling overhead and access latency.
Autors: Marco Centenaro;Lorenzo Vangelista;Stephan Saur;Andreas Weber;Volker Braun;
Appeared in: IEEE Transactions on Communications
Publication date: Sep 2017, volume: 65, issue:9, pages: 3832 - 3846
Publisher: IEEE
 
» Comparison of Constant-Posture Force-Varying EMG-Force Dynamic Models About the Elbow
Abstract:
Numerous techniques have been used to minimize error in relating the surface electromyogram (EMG) to elbow joint torque. We compare the use of three techniques to further reduce error. First, most EMG-torque models only use estimates of EMG standard deviation as inputs. We studied the additional features of average waveform length, slope sign change rate and zero crossing rate. Second, multiple channels of EMG from the biceps, and separately from the triceps, have been combined to produce two low-variance model inputs. We contrasted this channel combination with using each EMG separately. Third, we previously modeled nonlinearity in the EMG-torque relationship via a polynomial. We contrasted our model versus that of the classic exponential power law of Vredenbregt and Rau (1973). Results from 65 subjects performing constant-posture, force-varying contraction gave a “baseline” comparison error (i.e., error with none of the new techniques) of 5.5 ± 2.3% maximum flexion voluntary contraction (%MVCF). Combining the techniques of multiple features with individual channels reduced error to 4.8 ± 2.2 %MVCF, while combining individual channels with the power-law model reduced error to 4.7 ± 2.0 %MVCF. The new techniques further reduced error from that of the baseline by %.
Autors: Chenyun Dai;Berj Bardizbanian;Edward A. Clancy;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Sep 2017, volume: 25, issue:9, pages: 1529 - 1538
Publisher: IEEE
 
» Comparison on the Synchronization of Two Parallel GaAs Photoconductive Semiconductor Switches Excited by Laser Diodes
Abstract:
In this letter, the synchronization of GaAs photoconductive semiconductor switches in two electrically driven configurations for laser diodes excitation is investigated. Comparisons on the synchronization are carried out by varying the bias electric field and optical excitation energy. The optimum synchronization of 296 ps is achieved at 1.2 kV with optical excitation energy of . The results demonstrate the relationship between the synchronization and transient carriers’ population ratio among the intervalley.
Autors: Wei Shi;Yu Ji;Ming Xu;Cui Chen;Junjun Shi;Shaoqiang Wang;Rujun Liu;
Appeared in: IEEE Electron Device Letters
Publication date: Sep 2017, volume: 38, issue:9, pages: 1274 - 1277
Publisher: IEEE
 
» Comparison Study of Noncontact Vital Signs Detection Using a Doppler Stepped-Frequency Continuous-Wave Radar and Camera-Based Imaging Photoplethysmography
Abstract:
In this paper, we compare the performance of radar and optical (camera based) techniques in detecting vital signs such as respiratory rate (RR), heart rate (HR), and blood oxygen saturation (SpO2). Specifically, we investigate the application of ultrawideband stepped-frequency continuous-wave radar and imaging photoplethysmography (iPPG) techniques to measure vital signs. The radar performance can be enhanced by using phase information of backscattered signal instead of its amplitude. On the other hand, the iPPG system can be enhanced by using more than one camera and utilizing very selective narrowband filters coupled with good illumination. In either system, use of advanced signal processing is required to improve accuracy. Generally, HR and RR can be accurately read by either microwave radar or optical techniques with 500 lx illumination level to have < ±2% error up to 2 m distance between the subject and the system, but optical technique errors increase significantly to < ±15% for <200 lx. However, each system has its unique advantages as the radar can be used for seeing-through walls and optical technique is uniquely capable of measuring SpO2).
Autors: Lingyun Ren;Lingqin Kong;Farnaz Foroughian;Haofei Wang;Paul Theilmann;Aly E. Fathy;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3519 - 3529
Publisher: IEEE
 
» Compensation of Long-Term Memory Effects on GaN HEMT-Based Power Amplifiers
Abstract:
The long-term memory effects of gallium nitride (GaN) transistors have prevented its use in situations where the modulated envelope signal has a wide amplitude variation over time, such as in time division duplex systems. These long-term memory effects are generally attributed to electron trapping in GaN high electron-mobility transistors (HEMT), which have shown to be very difficult to compensate, especially in cellular base station transmitters known to be subjected to highly restrictive linearity specifications. On top of the electron trapping effects, we show that thermal effects can also induce long-term memory behaviors, which should also be accounted for when linearizing these devices. Because the conventional behavioral modeling approach has been incapable to compensate these long-term memory effects on GaN HEMT-based power amplifiers (PAs), we started by investigating the physical mechanisms responsible for these semiconductor impairments in GaN devices. This physics-based knowledge was then used to design new predistorter models that could effectively compensate those PAs subjected to GaN trapping and thermal effects. In this paper, we describe the new predistortion models for PA linearization, as well as the characterization methods used to determine their parameters. To validate the linearization effectiveness of the proposed model, several high power GaN-based PAs are tested with multicarrier GSM signals, and their linearization results are compared against other state-of-the-art models, evidencing a clear and significant improvement. In fact, to the authors’ knowledge, the proposed approach is the first one to reduce the PA distortion effects due to GaN long-term memory effects to such low levels, allowing a comfortable compliance with the imposed linearity masks.
Autors: Filipe M. Barradas;Luís C. Nunes;Telmo R. Cunha;Pedro M. Lavrador;Pedro M. Cabral;José C. Pedro;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3379 - 3388
Publisher: IEEE
 
» Complex Delta–Sigma-Based Transmitter With Enhanced Linearity Performance Using Pulsed Load Modulation Power Amplifier
Abstract:
This paper proposes a linear and efficient transmitter prototype based on pulsed load modulation (PLM) power amplifier (PA). The proposed transmitter setup utilizes the complex delta–sigma (DS) modulation as a signal processing technique instead of the envelope DS modulation for higher linearity performance. Using the complex DS modulation technique reduces the in-band quantization noise significantly at the output of the modulator and consequently, enhances the linearity of the transmitter. To validate the proposed technique, the linearity and efficiency performance of the complex DS modulator (CDSM)-based transmitter are compared with the performance of its envelope DS modulator (EDSM) counterpart in measurement. For this paper, an efficient and linear PLM PA is designed and fabricated using GaAs E-pHEMT transistors. For a Long-Term Evolution (LTE) uplink standard signal with 3-MHz bandwidth and 7-dB peak-to-average power ratio, the CDSM-based transmitter achieves the drain efficiency and power added efficiency of 46% and 42%, respectively, at an average output power of 25.1 dBm. The comparison measurement study of EDSM-based transmitter and the CDSM-based transmitter with the LTE uplink signal shows about 11-dB improvement in the signal-to-noise and distortion ratio of the output signal. The measurement results for LTE signals were able to pass the spectral requirements defined by the standard without applying predistortion techniques.
Autors: Maryam Jouzdani;Mohammad Mojtaba Ebrahimi;Mohamed Helaoui;Fadhel M. Ghannouchi;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3324 - 3335
Publisher: IEEE
 
» Composability Verification of Multi-Service Workflows in a Policy-Driven Cloud Computing Environment
Abstract:
The emergence of cloud computing infrastructure and Semantic Web technologies has created unprecedented opportunities for composing large-scale business processes and workflow-based applications that span multiple organizational domains. A key challenge related to composition of such multi-organizational business processes and workflows is posed by the security and access control policies of the underlying organizational domains. In this paper, we propose a framework for verifying secure composability of distributed workflows in an autonomous multi-domain environment. The objective of workflow composability verification is to ensure that all the users or processes executing the designated workflow tasks conform to the time-dependent security policy specifications of all collaborating domains. A key aspect of such verification is to determine the time-dependent schedulability of distributed workflows, assumed to be invoked on a recurrent basis. We use a two-step approach for verifying secure workflow composability. In the first step, a distributed workflow is decomposed into domain-specific projected workflows and is verified for conformance with the respective domain's security and access control policy. In the second step, the cross-domain dependencies amongst the workflow tasks performed by different collaborating domains are verified.
Autors: Basit Shafiq;Sameera Ghayyur;Ammar Masood;Zahid Pervaiz;Abdulrahman Almutairi;Farrukh Khan;Arif Ghafoor;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Sep 2017, volume: 14, issue:5, pages: 478 - 493
Publisher: IEEE
 
» Comprehensive Capacitance–Voltage Simulation and Extraction Tool Including Quantum Effects for High- $k$ on SixGe1−x and InxGa1−xAs: Part II—Fits and Extraction From Experimental Data
Abstract:
Capacitance-voltage (–) measurement and analysis is highly useful for determining important information about MOS gate stacks. Parameters such as the equivalent oxide thickness (EOT), substrate doping density, flatband voltage, fixed oxide charge, density of interface traps (), and effective gate work function can all be extracted from experimental – curves. However, to extract these gate-stack parameters accurately, the correct models must be utilized. In Part I, we described the modeling and implementation of a – code that can be used for alternative channel semiconductors in conjunction with high- gate dielectrics and metal gates. Importantly, this new code (CV ACE) includes the effects of nonparabolic bands and quantum capacitance, enabling accurate models to be applied to experimental – curves. In this paper, we demonstrate the capabilities of this new code to extract accurate parameters, including EOT and profiles from experimental high- on Ge and In0.53<- sub>Ga0.47As gate stacks.
Autors: Sarkar R. M. Anwar;William G. Vandenberghe;Gennadi Bersuker;Dmitry Veksler;Giovanni Verzellesi;Luca Morassi;Rohit V. Galatage;Sumit Jha;Creighton Buie;Adam T. Barton;Eric M. Vogel;Christopher L. Hinkle;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3794 - 3801
Publisher: IEEE
 
» Comprehensive Capacitance–Voltage Simulation and Extraction Tool Including Quantum Effects for High-k on SixGe1−x and InxGa1−xAs: Part I—Model Description and Validation
Abstract:
High-mobility alternative channel materials to silicon are critical to the continued scaling of MOS devices. The analysis of capacitance–voltage (C–V) measurements on these new materials with high-k gate dielectrics is a critical technique to determine many important gate-stack parameters. While there are very useful C–V analysis tools available to the community, these tools are all limited in their applicability to alternative semiconductor channel MOS gate-stack analysis since they were developed for silicon. Here, we report on a new comprehensive C–V simulation and extraction tool, called CV Alternative Channel Extraction (ACE), that incorporates a wide range of semiconductors and dielectrics with the capability to implement customized gate stacks. Fermi–Dirac carrier statistics, nonparabolic bands, and quantum mechanical effects are all implemented with options to turn each of these off as the user desires. Interface state capacitance () is implemented using a common model for systems like Si and Ge. A more complex model is also implemented for III–Vs that accurately captures frequency dispersion in accumulation that arises from tunneling. CV ACE enables extremely fast simulation and extraction and can accommodate measurements performed at variable temperatures and frequencies to allow for a more accurate extraction of interface state density ().
Autors: Sarkar R. M. Anwar;William G. Vandenberghe;Gennadi Bersuker;Dmitry Veksler;Giovanni Verzellesi;Luca Morassi;Rohit V. Galatage;Sumit Jha;Creighton Buie;Adam T. Barton;Eric M. Vogel;Christopher L. Hinkle;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3786 - 3793
Publisher: IEEE
 
» Compressed Level Crossing Sampling for Ultra-Low Power IoT Devices
Abstract:
Level crossing sampling (LCS) is a power-efficient analog-to-digital conversion scheme for spikelike signals that arise in many Internet of Things-enabled automotive and environmental monitoring applications. However, LCS scheme requires a dedicated time-to-digital converter with large dynamic range specifications. In this paper, we present a compressed LCS that exploits the signal sparsity in the time domain. At the compressed sampling stage, a continuous-time ternary encoding scheme converts the amplitude variations into a ternary timing signal that is captured in a digital random sampler. At the reconstruction stage, a low-complexity split-projection least squares (SPLSs) signal reconstruction algorithm is presented. The SPLS splits random projections and utilizes a standard least squares approach that exploits the ternary-valued amplitude distribution. The SPLS algorithm is hardware friendly, can be run in parallel, and incorporates a low-cost k-term approximation scheme for matrix inversion. The SPLS hardware is analyzed, designed, and implemented in FPGA, achieving the highest data throughput and the power efficiency compared with the prior arts. Simulations of the proposed sampler in an automotive collision warning system demonstrate that the proposed compressed LCS can be very power efficient and robust to wireless interference, while achieving an approximately eightfold data volume compression when compared with Nyquist sampling approaches.
Autors: Jun Zhou;Amir Tofighi Zavareh;Robin Gupta;Liang Liu;Zhongfeng Wang;Brian M. Sadler;Jose Silva-Martinez;Sebastian Hoyos;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Sep 2017, volume: 64, issue:9, pages: 2495 - 2507
Publisher: IEEE
 
» Compressed Training Adaptive Equalization: Algorithms and Analysis
Abstract:
We propose “compressed training adaptive equalization” as a novel framework to reduce the quantity of training symbols in a communication packet. It is a semi-blind approach for communication systems employing time-domain/frequency-domain equalizers, and founded upon the idea of exploiting the magnitude boundedness of digital communication symbols. The corresponding algorithms are derived by combining the least-squares-cost-function measuring the training symbol reconstruction performance and the infinity-norm of the equalizer outputs as the cost for enforcing the special constellation boundedness property along the whole packet. In addition to providing a framework for developing effective adaptive equalization algorithms based on convex optimization, the proposed method establishes a direct link with compressed sensing by utilizing the duality of the and norms. This link enables the adaptation of recently emerged -norm-minimization-based algorithms and their analysis to the channel equalization problem. In particular, we show for noiseless/low noise scenarios, the required training length is on the order of the logarithm of the channel spread. Furthermore, we provide approximate performance analysis by invoking the recent MSE results from the sparsity-based data processing literature. Provided examples illustrate the significant training reductions by the proposed approach and demonstrate its potential for high bandwidth systems with fast mobility.
Autors: Baki B. Yilmaz;Alper T. Erdogan;
Appeared in: IEEE Transactions on Communications
Publication date: Sep 2017, volume: 65, issue:9, pages: 3907 - 3921
Publisher: IEEE
 
» Condition Codes Evaluation on Dynamic Binary Translation for Embedded Platforms
Abstract:
A widely recognized issue when implementing dynamic binary translation is the condition codes (CCs) or flag bits emulation. The authors in the literature have approached this problem with software optimization techniques based on dataflow analysis, instruction set architecture (ISA) extensions and additional dedicated hardware, i.e., field-programmable gate array. We introduce a novel technique to handle CCs using commercial off-the-shelf architectural debug hardware as a triggering mechanism while assessing and comparing it with two existent CCs evaluation methods on the resource-constrained embedded systems arena. Our method is functionality-wise comparable with reconfigurable hardware modules or ISA extensions in open architectures and is source architecture independent, with possible applications in other use scenarios, such as application debugging and instrumentation.
Autors: Filipe Salgado;Tiago Gomes;Sandro Pinto;Jorge Cabral;Adriano Tavares;
Appeared in: IEEE Embedded Systems Letters
Publication date: Sep 2017, volume: 9, issue:3, pages: 89 - 92
Publisher: IEEE
 
» Conflict-Free Loop Mapping for Coarse-Grained Reconfigurable Architecture with Multi-Bank Memory
Abstract:
Coarse-grained reconfigurable architecture (CGRA) is a promising architecture with high performance, high power-efficiency and attraction of flexibility. The computation-intensive parts of an application (e.g., loops) are often mapped on CGRA for acceleration. Due to the high parallel data access demands, the architecture with multi-bank memory is proposed to improve parallelism. For CGRA with multi-bank memory, a joint solution, which simultaneously considers the memory partitioning and modulo scheduling, is proposed to achieve a valid mapping with better performance. In this solution, the modulo scheduling and operator scheduling are used to achieve a valid loop mapping and a valid data placement without any memory access conflicts. By avoiding the pipelining stalls caused by conflicts, the performance of loop mapping is greatly improved. The experimental results on benchmarks of the Livermore, Polybench and Mediabench show that our approach can improve the performance of loops on CGRA to 1.89, 1.49 and 1.37 compared with REGIMap, HTDM and REGIMap with memory partitioning, at cost of an acceptable increase in compilation time.
Autors: Shouyi Yin;Xianqing Yao;Tianyi Lu;Dajiang Liu;Jiangyuan Gu;Leibo Liu;Shaojun Wei;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Sep 2017, volume: 28, issue:9, pages: 2471 - 2485
Publisher: IEEE
 
» Confusion-Matrix-Based Kernel Logistic Regression for Imbalanced Data Classification
Abstract:
There have been many attempts to classify imbalanced data, since this classification is critical in a wide variety of applications related to the detection of anomalies, failures, and risks. Many conventional methods, which can be categorized into sampling, cost-sensitive, or ensemble, include heuristic and task dependent processes. In order to achieve a better classification performance by formulation without heuristics and task dependence, we propose confusion-matrix-based kernel logistic regression (CM-KLOGR). Its objective function is the harmonic mean of various evaluation criteria derived from a confusion matrix, such criteria as sensitivity, positive predictive value, and others for negatives. This objective function and its optimization are consistently formulated on the framework of KLOGR, based on minimum classification error and generalized probabilistic descent (MCE/GPD) learning. Due to the merits of the harmonic mean, KLOGR, and MCE/GPD, CM-KLOGR improves the multifaceted performances in a well-balanced way. This paper presents the formulation of CM-KLOGR and its effectiveness through experiments that comparatively evaluated CM-KLOGR using benchmark imbalanced datasets.
Autors: Miho Ohsaki;Peng Wang;Kenji Matsuda;Shigeru Katagiri;Hideyuki Watanabe;Anca Ralescu;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Sep 2017, volume: 29, issue:9, pages: 1806 - 1819
Publisher: IEEE
 
» Conic Programming-Based Lagrangian Relaxation Method for DCOPF With Transmission Losses and its Zero-Gap Sufficient Condition
Abstract:
This paper presents a fast optimization approach framework for the DC optimal power flow (DCOPF) with the consideration of transmission losses, which is confronted with nonconvex quadratically constrained quadratic programming. Specifically, a second-order cone programming-based Lagrangian relaxation method is employed to obtain the lower bound of the original DCOPF. Furthermore, a sufficient condition for the zero-gap relaxation is derived, which is easy to be satisfied in practice. Finally, the comparison with existing DCOPF solvers shows that the proposed method could achieve the global optimal solution and jump out of the local optimality. Also, the comparison with the widely used semidefinite programming relaxation approach indicates that the proposed relaxation method needs less dummy variables, and thus can be more efficiently solved and more applicable for large-scale power systems.
Autors: Tao Ding;Chaoyue Zhao;Tianen Chen;Ruifeng Liu;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3852 - 3861
Publisher: IEEE
 
» Connected Vehicular Transportation: Data Analytics and Traffic-Dependent Networking
Abstract:
With onboard operating systems becoming increasingly common in vehicles, the realtime broadband infotainment and intelligent transportation system (ITS) service applications in fast-moving vehicles become ever demanding, and they are expected to significantly improve the efficiency and safety of our daily on-road lives. The emerging ITS and vehicular applications (e.g., trip planning), however, require substantial efforts in real-time pervasive information collection and big data processing to allow quick decision making and feedback to fast-moving vehicles, which imposes significant challenges on the development of an efficient vehicular communication platform. In this article, we present TrasoNET, an integrated network framework that provides real-time intelligent transportation services to connected vehicles by exploring the data analytics and networking techniques. TrasoNET is built upon two key components. The first guides vehicles to the appropriate access networks by exploring the real-time status of local traffic, specific user preferences, service applications, and network conditions. The second mainly involves a distributed automatic access engine, which enables individual vehicles to make distributed access decisions based on recommendations, local observations, and historic information. We highlight the application of TrasoNET in a case study on real-time traffic sensing based on real traces of taxis.
Autors: Cailian Chen;Tom Hao Luan;Xinping Guan;Ning Lu;Yunshu Liu;
Appeared in: IEEE Vehicular Technology Magazine
Publication date: Sep 2017, volume: 12, issue:3, pages: 42 - 54
Publisher: IEEE
 
» Connecting Things to the IoT by Using Virtual Peripherals on a Dynamically Multithreaded Cortex M3
Abstract:
The Internet of Things communicates with the world by using a wide range of different sensors and actuators. These interfaces are based on a wide range of various protocols, such as I2C, SPI, RS232, 1-wire, and so on. There are two conceptional different solutions to provide these interfaces. One is to use dedicated hardware for it. An example would be to use a peripheral on a system-on-a-chip (SoC). All SoC providers offer the families of SoC solutions with different kind of hardware peripheral combinations. The alternative concept it to run virtual peripherals as a software routine on a CPU, preferable on a multithreaded CPU. C-Slow Retiming (CSR) is a known design transformation to generate multithreaded CPUs. This paper argues, that system hyper pipelining overcomes the limitations of CSR by adding thread stalling, bypassing, and reordering techniques to better cope with the challenges of multithreading. This dynamic multithreaded environment is ideal for running virtual peripheral. The benefits of using system hyper pipelining for virtual peripherals are demonstrated on a Cortex M3-based system.
Autors: Tobias Strauch;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Sep 2017, volume: 64, issue:9, pages: 2462 - 2469
Publisher: IEEE
 
» Considering Backhaul [Book\Software Reviews]
Abstract:
This book offers a comprehensive guide to the subject of microwave backhaul. Design information on this subject is sparse, and it is not easy to collect and interpret. This fact was the driving force behind the creation of this book, which focuses on the electronics of backhaul and describes in detail all the subsystems responsible for transforming the information signal that comes from baseband processing into an electromagnetic wave traveling through the air. Electronics for Microwave Backhaul presents an overview of the evolution of the electronics for microwave radios, from their initial development to present implementations and future trends. The authors have stayed abreast of current real-world industry products and present many real-world solutions to the design issues.
Autors: James Chu;
Appeared in: IEEE Microwave Magazine
Publication date: Sep 2017, volume: 18, issue:6, pages: 125 - 126
Publisher: IEEE
 
» Constant Compositions in the Sphere Packing Bound for Classical-Quantum Channels
Abstract:
The sphere packing bound, in the form given by Shannon, Gallager, and Berlekamp, was recently extended to classical-quantum channels, and it was shown that this creates a natural setting for combining probabilistic approaches with some combinatorial ones such as the Lovász theta function. In this paper, we extend the study to the case of constant-composition codes. We first extend the sphere packing bound for classical-quantum channels to this case, and we then show that the obtained result is related to a variation of the Lovász theta function studied by Marton. We then propose a further extension to the case of varying channels and codewords with a constant conditional composition given a particular sequence. This extension is finally applied to auxiliary channels to deduce a bound, which is useful in the low rate region and which can be interpreted as an extension of the Elias bound.
Autors: Marco Dalai;Andreas Winter;
Appeared in: IEEE Transactions on Information Theory
Publication date: Sep 2017, volume: 63, issue:9, pages: 5603 - 5617
Publisher: IEEE
 
» Constant Current Fast Charging of Electric Vehicles via a DC Grid Using a Dual-Inverter Drive
Abstract:
Existing integrated chargers are configured to charge from single- or three-phase ac networks. With the rapid emergence of dc grids, there is growing interest in the development of high-efficiency low-cost integrated chargers interfaced with dc power outlets. This paper introduces a new integrated charger offering electric vehicle fast charging from emerging dc distribution networks. In absence of a dc grid, the charger can alternatively be fed from a simple uncontrolled rectifier. The proposed charger leverages the dual-inverter topology previously developed for high-speed drive applications. By connecting the charger inlet to the differential ends of the traction inverters, charging is enabled for a wide battery voltage range previously unattainable using an integrated charger based on the single traction drive. An 11-kW experimental setup demonstrates rapid charging using constant current control and energy balancing of dual storage media. To minimize the harmonic impact of the charger on the dc distribution network, a combination of complementary and interleaved switching methods is demonstrated.
Autors: Ruoyun Shi;Sepehr Semsar;Peter W. Lehn;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 6940 - 6949
Publisher: IEEE
 
» Constellation Design Enhancement for Color-Shift Keying Modulation of Quadrichromatic LEDs in Visible Light Communications
Abstract:
Quadrichromatic light-emitting diode (QLED) cluster is a four-color solid-state apparatus suitable for simultaneous illumination and communications. Unlike traditional red/green/blue (RGB) LEDs, its extra color provides not only one new wavelength-division multiplexing data channel but also better color quality in illumination. Taking full consideration of the high quality of color rendering index (CRI) requirement with tunable color temperature (CT), this paper investigates the constellation design of color shift keying (CSK) to maximize the minimum pairwise Euclidean distance (MED) for communication performance optimization. Beyond existing works, maintaining a high-level CRI with a specified CT complicates our design optimization problem. We propose to transform the CRI requirement into a set of linear constraints on one of the LED source composition while jointly incorporating the CT constraints. Both simulation results and prototype CSK communication testbed measurements based on commercial multicolor LEDs (LUMILEDS Luxeon C) illustrate that, under the same luminous flux and CT conditions, our proposed flux independent CSK constellation for QLEDs can significantly enhance the MED, bit error rate, and illumination color qualities.
Autors: Xiao Liang;Ming Yuan;Jiaheng Wang;Zhi Ding;Ming Jiang;Chunming Zhao;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:17, pages: 3650 - 3663
Publisher: IEEE
 
» Construction $\pi _{A}$ and $\pi _{D}$ Lattices: Construction, Goodness, and Decoding Algorithms
Abstract:
A novel construction of lattices is proposed. This construction can be thought of as a special class of Construction A from codes over finite rings that can be represented as the Cartesian product of linear codes over , respectively, and hence is referred to as Construction . The existence of a sequence of such lattices that is good for channel coding (i.e., Poltyrev-limit achieving) under multistage decoding is shown. A new family of multilevel nested lattice codes based on Construction lattices is proposed and its achievable rate for the additive white Gaussian noise channel is analyzed. A generalization named Construction is also investigated, which subsumes Construction A with codes over prime fields, Construction D, and Construction as special cases.
Autors: Yu-Chih Huang;Krishna R. Narayanan;
Appeared in: IEEE Transactions on Information Theory
Publication date: Sep 2017, volume: 63, issue:9, pages: 5718 - 5733
Publisher: IEEE
 
» Construction of Highly Nonlinear 1-Resilient Boolean Functions With Optimal Algebraic Immunity and Provably High Fast Algebraic Immunity
Abstract:
In 2013, Tang, Carlet, and Tang [IEEE TIT 59(1): 653–664, 2013] presented two classes of Boolean functions. The functions in the first class are unbalanced and the functions in the second one are balanced. Both of those two classes of functions have high nonlinearity, high algebraic degree, optimal algebraic immunity, and high fast algebraic immunity. However, they are not 1-resilient which represents a drawback for their use as filter functions in stream ciphers. In this paper, we first propose a large family of 1-resilient Boolean functions having high lower bound on nonlinearity, optimal algebraic immunity, and optimal algebraic degree, that is, meeting the Siegenthaler bound. Most notably, we can mathematically prove that every function in variables belonging to this family has fast algebraic immunity no less than , which is the first time that an infinite family of 1-resilient functions with provably high fast algebraic immunity has been invented. Furthermore, we exhibit a subclass of the family which has higher lower bound on nonlinearity than all the known 1-resilient functions with (potentially) optimal algebraic immunity and potentially high fast algebraic immunity.
Autors: Deng Tang;Claude Carlet;Xiaohu Tang;Zhengchun Zhou;
Appeared in: IEEE Transactions on Information Theory
Publication date: Sep 2017, volume: 63, issue:9, pages: 6113 - 6125
Publisher: IEEE
 
» Continued Dispute on Preferred Vehicle-to-Vehicle Technologies [Connected Vehicles]
Abstract:
As reported in the June issue of IEEE Vehicular Technology Magazine [1], the National Highway Traffic Safety Administration (NHTSA) Department of Transportation has issued a proposed rule, "The Federal Motor Vehicle Safety Standard (FMVSS); Vehicle-to-Vehicle (V2V) Communications," that would require automakers to include V2V technologies in all new light-duty vehicles. The proposed rule was open for public comments until 12 April and received several replies, which were most notably from four different stakeholders, reflecting the still-ongoing heated debate about sharing the intelligent transport systems (ITS) frequency band in the United States.
Autors: Elisabeth Uhlemann;
Appeared in: IEEE Vehicular Technology Magazine
Publication date: Sep 2017, volume: 12, issue:3, pages: 17 - 20
Publisher: IEEE
 
» Continuous Estimation of Human Multi-Joint Angles From sEMG Using a State-Space Model
Abstract:
Due to the couplings among joint-relative muscles, it is a challenge to accurately estimate continuous multi-joint movements from multi-channel sEMG signals. Traditional approaches always build a nonlinear regression model, such as artificial neural network, to predict the multi-joint movement variables using sEMG as inputs. However, the redundant sEMG-data are always not distinguished; the prediction errors cannot be evaluated and corrected online as well. In this work, a correlation-based redundancy-segmentation method is proposed to segment the sEMG-vector including redundancy into irredundant and redundant subvectors. Then, a general state-space framework is developed to build the motion model by regarding the irredundant subvector as input and the redundant one as measurement output. With the built state-space motion model, a closed-loop prediction-correction algorithm, i.e., the unscented Kalman filter (UKF), can be employed to estimate the multi-joint angles from sEMG, where the redundant sEMG-data are used to reject model uncertainties. After having fully employed the redundancy, the proposed method can provide accurate and smooth estimation results. Comprehensive experiments are conducted on the multi-joint movements of the upper limb. The maximum RMSE of the estimations obtained by the proposed method is 0.16±0.03, which is significantly less than 0.25±0.06 and 0.27±0.07 (p < 0.05) obtained by common neural networks.
Autors: Qichuan Ding;Jianda Han;Xingang Zhao;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Sep 2017, volume: 25, issue:9, pages: 1518 - 1528
Publisher: IEEE
 
» Control of Mutual Coupling in High-Field MRI Transmit Arrays in the Presence of High-Permittivity Liners
Abstract:
In high-field magnetic resonance imaging, transmit arrays and high-permittivity inserts are often used together to mitigate the effects of RF field inhomogeneities due to short wavelength. However, array performance is limited by mutual impedance between elements which must be closely spaced around the volume of interest. Mutual impedance plays a substantial role at high frequencies and is increased by the presence of dielectric pads which are used to increase the homogeneity of the RF magnetic field. This paper describes a decoupling strategy for an eight-channel transmit/receive array in the presence of a high permittivity dielectric liner. The elements are decoupled using capacitive bridges between adjacent elements. In spite of the higher mutual impedance due to the liner, both mutual resistance and reactance can be removed between adjacent elements (isolation better than 30 dB), and coupling between nonadjacent elements is maintained below 15 dB. The effects of decoupling on the transmit performance of the array in presence of high permittivity liners are investigated in terms of coupling, magnetic field intensity, SAR and transmit efficiencies.
Autors: Atefeh Kordzadeh;Nicola De Zanche;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3485 - 3491
Publisher: IEEE
 
» Control of Widely Tunable Lasers With High-Q Resonator as an Integral Part of the Cavity
Abstract:
We have designed and fabricated widely tunable semiconductor laser with a high-Q resonator as an integral part of the laser cavity. Wide tuning is realized by utilizing the Vernier effect of two rings with slightly different circumferences. A third ring with considerably larger circumference, and, consequently, higher Q is introduced inside the laser cavity. We study the control of such a laser and show that it is straightforward provided that the integrated laser has on-chip monitor photodiodes. This further shows the benefits of full integration as inclusion of additional monitor photodetectors is straightforward with no extra processing steps. As the complexity of photonic-integrated chips increases, the inclusion of more monitor photodetectors for control is necessary.
Autors: Tin Komljenovic;Songtao Liu;Erik Norberg;Gregory A. Fish;John E. Bowers;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:18, pages: 3934 - 3939
Publisher: IEEE
 
» Control Strategy to Eliminate Impact of Voltage Measurement Errors on Grid Current Performance of Three-Phase Grid-Connected Inverters
Abstract:
This study proposes an advanced current control strategy for three-phase grid-connected inverters to reject the impact of the dc offsets and scaling errors in the grid voltage measurement on the grid current performance. The proposed current controller designed in the synchronous (d-q) reference frame is developed with a proportional integral (PI) plus three vector PI controllers. The PI controller regulates the fundamental current to follow its reference, meanwhile, three vector PI controllers tuned at the fundamental grid frequency (), , are employed to eliminate the dc, unbalance, harmonic components in the grid current. As a result, the three-phase grid currents are controlled to be balanced, sinusoidal, and extremely low dc component despite the presence of the dc offset and scaling errors in the grid voltage measurement and distorted grid voltage conditions. The main advantage of the proposed control scheme is that it is developed without the need of additional hardware circuit, dc extraction, and harmonic detection scheme so that it can be integrated into the existing grid-connected inverter system without extra cost. The effectiveness of the suggested solution is verified by experimental results under various grid voltage conditions and the grid voltage measurement errors.
Autors: Quoc-Nam Trinh;Fook Hoong Choo;Peng Wang;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7508 - 7519
Publisher: IEEE
 
» Controlling Soft Robots: Balancing Feedback and Feedforward Elements
Abstract:
Soft robots (SRs) represent one of the most significant recent evolutions in robotics. Designed to embody safe and natural behaviors, they rely on compliant physical structures purposefully designed to embody desirable and sometimes variable impedance characteristics. This article discusses the problem of controlling SRs. We start by observing that most of the standard methods of robotic control-e.g., high-gain robust control, feedback linearization, backstepping, and active impedance control-effectively fight against or even completely cancel the physical dynamics of the system, replacing them with a desired model. This defeats the purpose of introducing physical compliance. After all, what is the point of building soft actuators if we then make them stiff by control?
Autors: Cosimo Della Santina;Matteo Bianchi;Giorgio Grioli;Franco Angelini;Manuel Catalano;Manolo Garabini;Antonio Bicchi;
Appeared in: IEEE Robotics & Automation Magazine
Publication date: Sep 2017, volume: 24, issue:3, pages: 75 - 83
Publisher: IEEE
 
» Cooperation of Wind Power and Battery Storage to Provide Frequency Regulation in Power Markets
Abstract:
In the future power system with high penetration of renewables, renewable energy is expected to undertake part of the responsibility for frequency regulation, just as the conventional generators. Wind power and battery storage are complementary in accuracy and durability when providing frequency regulation. Therefore, it would be profitable to combine wind power and battery storage as a physically connected entity or a virtual power plant to provide both energy and frequency regulation in the markets. This paper proposes a real-time cooperation scheme to exploit their complementary characteristics and an optimal bidding strategy for them in joint energy and regulation markets, considering battery cycle life. The proposed cooperation scheme is adopted in a real-time battery operating simulation and then incorporated into the optimal bidding model. The scheme could improve the wind regulation performance score and allow for more regulation bids without affecting the battery life, thus significantly increasing the overall revenue. The validity of the proposed scheme and strategy are proved by the case study.
Autors: Guannan He;Qixin Chen;Chongqing Kang;Qing Xia;Kameshwar Poolla;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3559 - 3568
Publisher: IEEE
 
» Cooperation-Based Probabilistic Caching Strategy in Clustered Cellular Networks
Abstract:
This letter will discuss the probabilistic caching strategies in spatially clustered cellular networks. Thanks to the content preference of mobile users, proactive caching can be adopted as a promising technique to diminish the backhaul traffic and to decrease the content delivery latency. However, basically there are two obstacles to accomplish the caching policy, i.e., the limited storage capacity of small cells to cache large amount of multimedia contents, and the too small number of users under each base station to imply the content aggregation effect. Traditional caching strategies of the base station only concern its local requests from the connected users through wireless links, but neglect the potential benefit from the cluster feature of the network infrastructure and user traffic demand. In this letter, we proposed a new policy called "Caching as a Cluster", where small cells can exchange content with each other to fulfill every user request within the cluster of base stations. Intuitively, this cooperation between base stations makes a difference to decrease the content delivery latency of mobile users in clustered cellular networks as testified in our numerical simulation.
Autors: Yifan Zhou;Zhifeng Zhao;Rongpeng Li;Honggang Zhang;Yves Louet;
Appeared in: IEEE Communications Letters
Publication date: Sep 2017, volume: 21, issue:9, pages: 2029 - 2032
Publisher: IEEE
 
» Cooperation-Driven Distributed Control Scheme for Large-Scale Wind Farm Active Power Regulation
Abstract:
Being more actively involved in the electricity market and power systems, wind farms are urgently expected to have similar controllable behavior to conventional generations so that demand assigned by the system operator can be met. However, determining the method of dispatching the reference among the widely spread and low-rating wind turbines is difficult. This paper provides a cooperation-driven distributed control scheme for wind farm active power regulation. Instead of competing with neighboring controllers completely, the control strategy evaluates system-wide impacts of local control actions, and aims to achieve coordinated control effect. In addition, the kinetic energy storage potential in a wind turbine is tapped to provide a buffer for power dispatch. Case studies demonstrate that a large wind farm can be effectively controlled to accurately track the demand power through the proposed control scheme.
Autors: Xiaodan Gao;Ke Meng;Zhao Yang Dong;Dongxiao Wang;Mohamed Shawky El Moursi;Kit Po Wong;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 1240 - 1250
Publisher: IEEE
 
» Cooperative Jamming for Secure Communication With Finite Alphabet Inputs
Abstract:
This letter considers cooperative jamming to secure communication in the presence of multiple eavesdroppers with finite alphabet inputs. Considering the global constraint, the joint design of artificial noise covariance matrices and power allocation between the source and the relays is studied. Specifically, we transformed the problem of artificial noise design into a semi-definite programming problem, which is efficiently solved by standard optimization method. Besides, the power allocation between the source and relays is derived by utilizing the relationship between mutual information and minimum mean square error. Furthermore, a two-step algorithm is developed to enhance the achievable secrecy rate of cooperative jamming wireless network. Numerical examples demonstrate the proposed algorithm achieves a significant gain over the conventional counterparts in terms of secrecy rate.
Autors: Kuo Cao;Yueming Cai;Yongpeng Wu;Weiwei Yang;
Appeared in: IEEE Communications Letters
Publication date: Sep 2017, volume: 21, issue:9, pages: 2025 - 2028
Publisher: IEEE
 
» Coordinated Control Strategies for Offshore Wind Farm Integration via VSC-HVDC for System Frequency Support
Abstract:
Coordinated control strategies to provide system inertia support for main grid from offshore wind farm that is integrated through HVdc transmission is the subject matter of this paper. The strategy that seeks to provide inertia support to the main grid through simultaneous utilization of HVdc capacitors energy, and wind turbines (WTs) inertia without installing the remote communication of two HVdc terminals is introduced in details. Consequently, a novel strategy is proposed to improve system inertia through sequentially exerting dc capacitors energy and then WTs inertia via a cascading control scheme. Both strategies can effectively provide inertia support while the second one minimizes the control impacts on harvesting wind energy with the aid of communication between onshore and offshore ac grids. Case studies of a wind farm connecting with a HVdc system considering sudden load variations have been successfully conducted to compare and demonstrate the effectiveness of the control strategies in DIgSILENT/PowerFactory.
Autors: Yujun Li;Zhao Xu;Jacob Østergaard;David J. Hill;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 843 - 856
Publisher: IEEE
 

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