Electrical and Electronics Engineering publications abstract of: 01-2017 sorted by title, page: 3

» Analysis of Voltage Sag Severity Case Study in an Industrial Circuit
Abstract:
This paper presents the results of a power quality study carried out in an industrial distribution system. The main objective of this study was to quantify the negative impact caused by voltage sags in industrial processes and its relationship to generated interruptions. A series of measurements of power quality variations were taken at the substation that feeds the circuit and at the point-of-common coupling of each industrial user. The new standard IEEE Std 1564-2014 “Guide for Voltage Sag Indices” was used to determine the indicators to assess the severity of voltage sags and also the calculation method. Sag severity was selected as it allows the calculation of the probability of voltage sags to generate interruptions in industrial processes or electrical equipment. Thus, an analysis of the quality of the supply voltage can be done. Severity was initially calculated at the substation that feeds the industrial circuit and later, at the point-of-common coupling of each user. Subsequently, the relationship between user interruptions and severity values was determined. Finally, recommendations of good engineering practices in industrial processes were done.
Autors: Santiago Arias-Guzmán;Oscar Andrés Ruiz-Guzmán;Luís Felipe Garcia-Arías;María Jaramillo-Gonzáles;Pablo Daniel Cardona-Orozco;Armando J. Ustariz-Farfán;Eduardo A. Cano-Plata;Andrés Felipe
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 15 - 21
Publisher: IEEE
 
» Analytical Drain Current Compact Model in the Depletion Operation Region of Short-Channel Triple-Gate Junctionless Transistors
Abstract:
A new charge-based analytical compact model for the drain current of junctionless (JL) triple-gate MOSFETs is presented, which includes the short-channel effects, the saturation velocity overshoot, the series resistance, and the mobility degradation effects. The proposed model consists of a single analytical equation that covers the depletion operation region in which the bulk conduction determines the drain current. The model is supported by experimental measurements in JL nanowire transistors with channel length varying from 95 to 25 nm and doping concentration cm. The overall results reveal the very good accuracy of the proposed analytical compact model, making it suitable for circuit simulation tools.
Autors: Theodoros A. Oproglidis;Andreas Tsormpatzoglou;Dimitrios H. Tassis;Theano A. Karatsori;Sylvain Barraud;Gérard Ghibaudo;Charalabos A. Dimitriadis;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 66 - 72
Publisher: IEEE
 
» Analytical Performance Evaluation of VDSL2
Abstract:
In this letter, we model the downstream bit rate per user for VDSL2-based access systems as normal random variable. Its statistics are expressed in closed analytic forms explicitly accounting for FEXT fluctuation and for the access network geometry. The considered approximation is obtained assuming log-normal statistics for the signal-to-interference plus noise ratio per sub-carrier. The validity of this model has been assessed by computer calculation showing a very good agreement between the exact and the approximated bit rates.
Autors: Franco Mazzenga;Romeo Giuliano;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 44 - 47
Publisher: IEEE
 
» Ancillary Services Through Demand Scheduling and Control of Commercial Buildings
Abstract:
Prior work showed building Heating, Ventilation, Air Conditioning (HVAC) systems can provide ancillary services to the power grid without sacrificing occupant comfort if the reference power variation is of high frequency (seconds to a few minutes). This paper addresses the question of how to do that when the reference power variation is of lower frequency, e.g., periods of a few minutes to an hour. The proposed control system to do so uses a two-layer architecture. An optimizer schedules the baseline cooling and heating power of a building based on load forecasts. A lower level controller is then used to track the scheduled baseline plus ancillary service reference signal. The schedule is periodically updated based on indoor measurements to ensure quality of service in spite of load forecasting error. The algorithm is tested in simulation. Results show that ancillary services in the frequency range of can be extracted from commercial building HVAC systems while still maintaining a comfortable indoor climate.
Autors: Yashen Lin;Prabir Barooah;Johanna L. Mathieu;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 186 - 197
Publisher: IEEE
 
» Anger Management [MicroBusiness]
Abstract:
Discusses approaches to deal with anger management in the workplace.
Autors: Fred Schindler;
Appeared in: IEEE Microwave Magazine
Publication date: Jan 2017, volume: 18, issue:1, pages: 18 - 20
Publisher: IEEE
 
» Angle Correction in Optopalatographic Tongue Distance Measurements
Abstract:
Optopalatography (OPG) is an optical technique to measure the distance between the hard palate and the tongue surface inside the mouth during articulation. The conventional way to measure this distance is only accurate for the special case that the tongue surface is oriented perpendicular to the optical axes of the optical sensors. It introduces an error in the much more common case that the tongue is angled with respect to the sensor axes. In this paper, we present a technique to compensate that error by using a newly devised complete model of light propagation for arbitrary source-reflector-detector setups that considers the complex reflective properties of the tongue surface due to sub-surface scattering. Optimal parameters for our model are found by fitting it to a data set of real-world measurements. For any given arrangement of sensors, simulations of this model can be used to obtain optimal coefficients for a distance error correction term. This term reduces the mean distance error of in vivo data recorded with our electrooptical stomatography (EOS, a multi-modal technique that includes OPG) hardware prototype from 7.38% to 2.25% and the standard deviation from 2.79% to 1.9%. The results are used to significantly improve the precision and accuracy of the distance measurements in real-time EOS recordings and example tongue contours of five German vowels are presented.
Autors: Simon Stone;Peter Birkholz;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2017, volume: 17, issue:2, pages: 459 - 468
Publisher: IEEE
 
» Angle Difference Method for Vehicle Navigation in Multilevel Road Networks With a Three-Dimensional Transport GIS Database
Abstract:
Multilevel road networks such as grade-separated interchanges and elevated roads have been increasingly used to solve traffic congestion in large cities. When navigating a vehicle in a multilevel road network, identifying the location of the vehicle in different road levels is of equal importance to identifying its planar location, particularly for overlapping and parallel roads. Although they can be represented and visualized in the existing navigation system, at present, it is difficult to guide a vehicle through such a multilevel road network because the existing vehicle positioning system uses consumer-grade GPS, and the transport geographic information system (GIS-T) database is mainly 2-D-based. The location of a vehicle on diffrent road levels in multilevel road networks is often overlooked. This paper examines the deficiency of existing approaches in supporting vehicle navigation in multilevel road networks with consumer-grade GPS. It proposes to use an angle difference method that compares the vehicle pitch angle with the inclination angles of different road levels calculated from road elevations stored in the proposed GIS-T database to snap the vehicle to the appropriate road level when the vehicle is entering or exiting a multilevel road network. The angle difference method is implemented based on consumer-grade assisted GPS (A-GPS) and onboard vehicle pitch angle measurement with smartphone. Experiment results prove that the angle difference method have high accuracy in determining the road level when the vehicle is driving in a parallel multilevel road network.
Autors: Anthony Gar-On Yeh;Teng Zhong;Yang Yue;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2017, volume: 18, issue:1, pages: 140 - 152
Publisher: IEEE
 
» Anisotropic Conductivity Tensor Imaging of In Vivo Canine Brain Using DT-MREIT
Abstract:
We present in vivo images of anisotropic electrical conductivity tensor distributions inside canine brains using diffusion tensor magnetic resonance electrical impedance tomography (DT-MREIT). The conductivity tensor is represented as a product of an ion mobility tensor and a scale factor of ion concentrations. Incorporating directional mobility information from water diffusion tensors, we developed a stable process to reconstruct anisotropic conductivity tensor images from measured magnetic flux density data using an MRI scanner. Devising a new image reconstruction algorithm, we reconstructed anisotropic conductivity tensor images of two canine brains with a pixel size of 1.25 mm. Though the reconstructed conductivity values matched well in general with those measured by using invasive probing methods, there were some discrepancies as well. The degree of white matter anisotropy was 2 to 4.5, which is smaller than previous findings of 5 to 10. The reconstructed conductivity value of the cerebrospinal fluid was about 1.3 S/m, which is smaller than previous measurements of about 1.8 S/m. Future studies of in vivo imaging experiments with disease models should follow this initial trial to validate clinical significance of DT-MREIT as a new diagnostic imaging modality. Applications in modeling and simulation studies of bioelectromagnetic phenomena including source imaging and electrical stimulation are also promising.
Autors: Woo Chul Jeong;Saurav Z. K. Sajib;Nitish Katoch;Hyung Joong Kim;Oh In Kwon;Eung Je Woo;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2017, volume: 36, issue:1, pages: 124 - 131
Publisher: IEEE
 
» Anomalies in Interpretation of Transformer Oil Tests for Thermally Upgraded Paper—A Case History
Abstract:
Continuity of an electrical power supply to continuous processes is vital for overall success in an industrial setting. It is, therefore, critically important to accurately evaluate the degree to which the transformer insulation has been exposed to high temperatures and the degree of service aging which has occurred, even at normal temperatures. Concentration of carbon oxides dissolved in the oil is one marker commonly used, and concentration of furans dissolved in the oil is another. Sometimes, an apparent anomaly may develop in which the concentration of carbon oxides indicates a substantial long-term overheating, while at the same time the concentration of furans indicates that there has been a little aging of the solid insulation. Actual instances are analyzed and a logical explanation is developed. Guidelines are presented which address the development of this confusing situation and allow for logical conclusions as to the actual condition of the insulation system.
Autors: Stanley Y. Merritt;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 780 - 784
Publisher: IEEE
 
» Antenna on Cavity Backed High Impedance Surface
Abstract:
A low profile (), lightweight, linearly polarized antenna has been designed for 0.9 GHz applications using a double layered via-less high impedance surface (HIS). The weight of the antenna is reduced by removing the dielectric layer between the HIS and the ground plane. In order to suppress the back lobe, we propose the use of a cavity. Since the entire structure lies below the surface of the ground, the proposed antenna can be used on moving platforms, especially for airborne applications.
Autors: Gaurangi Gupta;A. R. Harish;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2017, volume: 65, issue:1, pages: 374 - 379
Publisher: IEEE
 
» API 541 Variable Speed Medium Voltage Motors Applied in a Class I, Division 1 Hazardous Location—A Case Study
Abstract:
When a petrochemical installation requires the use of Class I, Division 1 electric motors for hazardous areas, end users in North America must find motors certified to the applicable national standards for such equipment. In North America, National Fire Protection Association 70 (NFPA 70 or National Electrical Code or NEC) and Canadian electrical code electric motors with explosion-proof certification are not unusual for low voltage installations, but are uncommon when larger power medium voltage applications are required. Medium voltage motors with Class I, Division 2 suitability are common, but are hard to find with an explosion-proof certification. Petrochemical applications for medium voltage motors also commonly require use of the American Petrochemical Institute Standard 541 (API 541). Further, some applications additionally require use of an adjustable speed drive to vary the speed of the driven equipment to fit operational considerations. In one recent instance, when an end user attempted to specify a 1500-kW motor with the combination of explosion-proof certification, adjustable speed suitability, and API 541 features/testing, no manufacturer in the world had such a motor available. While other solutions were considered, the end user preferred the straightforward approach that a Class I, Division 1 motor offered and decided to work with a manufacturer of motors meeting International Electrotechnical Commission (IEC) flameproof standards to satisfy the combination of all application requirements for this installation. There are many differences between the NEC and IEC systems governing hazardous areas and motor certifications are not interchangeable. The end user's engineers had to learn and understand the differences between these systems and this case study addresses many of the technical requirements, issues, and effort required to successfully deliver this motor to the project.
Autors: Merwyn D'Souza;Imad Malek;Tim Rahill;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 731 - 738
Publisher: IEEE
 
» Application of a Phasor-Only State Estimator to a Large Power System Using Real PMU Data
Abstract:
This paper applies a phasor-only state estimator (PSE) to a large power system consisting of two control regions, using synchrophasor data from 56 765/345/230 kV substations. Although the technique has been previously developed, this paper describes a topology processor to determine the redundant clusters of connected buses such that the PSE can be used in real time. This PSE allows corrections for phase biases, transformer taps, and current magnitude scaling. The ability to simultaneously solve the PSE for the two control regions is due to a PMU monitoring a tie-line between these two regions. The results show that with this method, the total vector errors of the measured voltage phasor data in these two control regions average to less than 0.5% under ambient conditions. The PSE also computes virtual phasor measurements on 70 buses that do not have PMUs, including large steam generator and wind-turbine generator substations.
Autors: Emily R. Fernandes;Scott G. Ghiocel;Joe H. Chow;Daniel E. Ilse;De D. Tran;Qiang Zhang;David B. Bertagnolli;Xiaochuan Luo;George Stefopoulos;Bruce Fardanesh;Russell Robertson;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 411 - 420
Publisher: IEEE
 
» Applications of Capacity Limits to Performance Analyses of Adaptive Transmission Protocols for Packet Radios
Abstract:
Analytical methods are provided for use in performance evaluations, tradeoff studies, and preliminary designs of adaptive modulation and coding protocols that obtain their control information from practical sources. Our approach employs capacity limits and Markov chain models of fading to give analytical results on the throughput achieved by adaptive transmission in packet radio systems. The analytical methods replace simulations of the modem, iterative decoder, and time-varying fading channel. The amount of processor time required for protocol performance evaluations is decreased by several orders of magnitude.
Autors: Siddhartha S. Borkotoky;Michael B. Pursley;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 71 - 78
Publisher: IEEE
 
» Approximate Area-to-Point Regression Kriging for Fast Hyperspectral Image Sharpening
Abstract:
Area-to-point regression kriging (ATPRK) is an advanced image fusion approach in remote sensing In this paper, ATPRK is considered for sharpening hyperspectral images (HSIs), based on the availability of a fine spatial resolution panchromatic or multispectral image. ATPRK can be used straightforwardly to sharpen each coarse hyperspectral band in turn. This scheme, however, is computationally expensive due to the large number of bands in HSIs, and this problem is exacerbated for multiscene or multitemporal analysis. Thus, we extend ATPRK for fast HSI sharpening with a new approach, called approximate ATPRK (AATPRK), which transforms the original HSI to a new feature space and image fusion is performed for only the first few components before back transformation. Experiments on two HSIs show that AATPRK greatly expedites ATPRK, but inherits the advantages of ATPRK, including maintaining a very similar performance in sharpening (both ATPRK and AATPRK can produce more accurate results than seven benchmark methods) and precisely conserving the spectral properties of coarse HSIs.
Autors: Qunming Wang;Wenzhong Shi;Peter M. Atkinson;Qi Wei;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 286 - 295
Publisher: IEEE
 
» Approximate Safety Verification and Control of Partially Observable Stochastic Hybrid Systems
Abstract:
Assuring safety in stochastic hybrid systems is particularly difficult when only noisy or partial observations of the state are available. We first review a formulation of the probabilistic safety problem under partial hybrid observations as a dynamic program over an equivalent information state. Two methods for approximately solving the dynamic program are presented. The first approximates the hybrid system as a finite state Markov decision process, so that the information state is a probability mass function. The second method approximates an indicator function over the safe region using radial basis functions, to represent the information state as a Gaussian mixture. In both cases we discretize the hybrid observation process, then use point-based value iteration to under-approximate the safety probability and synthesize a safety-preserving control policy. We obtain error bounds and convergence results in both cases, assuming switched affine dynamics and additive Gaussian noise on the continuous states and observations. We compare the performance of the finite state and Gaussian mixture approaches on a simple numerical example.
Autors: Kendra Lesser;Meeko Oishi;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2017, volume: 62, issue:1, pages: 81 - 96
Publisher: IEEE
 
» Area Spectral Efficiency Analysis of Multi-Antenna Two-Tier Cellular Networks
Abstract:
This letter investigates the area spectral efficiency (ASE) of a two-tier network with multi-antenna base stations (BSs). Based on a tractable approximation, some key properties of ASE are analytically revealed. We demonstrate that the additional deployment of small-cell BSs is efficient for improving ASE. For the purpose of ASE maximization, the optimal number of active users is derived for each tier, which has a linear relationship with the number of antennas. Furthermore, under the optimal condition, ASE will increase linearly with the number of antennas. Different from single-antenna networks, we observe that range expansion can have either a positive or a negative effect on ASE.
Autors: Zheng Chen;Ling Qiu;Xiao Wen Liang;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 108 - 111
Publisher: IEEE
 
» Art of Generator Synchronizing
Abstract:
This paper presents a review of power-system synchronization, proper sync-check coordination, and fast synchronization methods. When paralleling two sources, it is crucial that the interconnecting circuit breaker be closed only when both sources are in voltage, frequency, and phase coincidence. An operator can synchronize manually or use one of the latest, state-of-the-art automatic synchronizers (ANSI/IEEE device 25A) and sync-check relays (ANSI/IEEE device 25) to automate closing. Generator and bus synchronization share most principles—with some important differences—for each type of synchronization. For generation plants, the method of generator synchronization selected depends greatly on the plant configuration and operating mode. For bus-line applications, the synchronizing method selected depends on the power-system “stiffness,” motor loads, and whether a wye-delta transformer is located between the line and bus.
Autors: Richard C. Schaefer;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 751 - 757
Publisher: IEEE
 
» Artificial-Noise-Aided Secure Transmission Scheme With Limited Training and Feedback Overhead
Abstract:
We design a novel artificial-noise-aided secure ON–OFF transmission scheme in a wiretap channel. We consider a practical scenario, where the multi-antenna transmitter only obtains partial channel knowledge from the single-antenna receiver through limited training and feedback but has no channel knowledge about the single-antenna eavesdropper. In the design, we first propose a three-period block transmission protocol to capture the practical training and quantization features. We then characterize the statistics of the received signal-to-noise ratios at the receiver and the eavesdropper. Under the secrecy outage constraint, we exploit the ON–OFF scheme to perform secure transmission and derive a closed-form expression for the secrecy throughput. Moreover, we investigate the optimization problem of maximizing the secrecy throughput by proposing an iterative algorithm to determine the optimal power allocation between the information signal and artificial noise, as well as the optimal codeword transmission rate. Furthermore, we define the net secrecy throughput (NST), which takes the signaling overhead into account and address the problem of optimally allocating the block resource to the training and feedback overhead. Numerical results clearly demonstrate how the optimal signaling overhead changes with the number of transmit antennas, and there exists an optimal number of antennas that maximizes the NST.
Autors: Jianwei Hu;Yueming Cai;Nan Yang;Xiangyun Zhou;Weiwei Yang;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 193 - 205
Publisher: IEEE
 
» Assessment of Scalable and Fast 1310-nm Optical Switch for High-Capacity Data Center Networks
Abstract:
The development of high-capacity 1310-nm optical interconnects and the limitation of the electrical switches have necessitated the investigation of 1310-nm optical switches for flat data center networks. We have performed an experimental assessment of the scalable and fast 1310-nm optical switching system with three types of traffic, namely, the waveband Gb/s on–off keying (OOK), 28 Gb/s 4-level pulse-amplitude modulation (PAM4), and 40 Gb/s discrete multi-tone (DMT) by using the prototyped 1310-nm optical switch. 10-dB input power dynamic range has been achieved at 16 ports for waveband Gb/s, 28-Gb/s PAM4, and 40-Gb/s DMT with power penalty of 1, 3, and 3.3 dB, respectively. Waveband Gb/s OOK traffic shows the most promising results with port-count scaling up to 64 ports with limited penalty and allows for the potential scaling to larger port-count and more wavelength channels.
Autors: Wang Miao;Huug de Waardt;Robbert van der Linden;Nicola Calabretta;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:1, pages: 98 - 101
Publisher: IEEE
 
» Assistive Intelligent Robotic Wheelchairs
Abstract:
In a world where technological achievements and breakthroughs are astonishing and where computers and all kinds of electronic devices have become one with their users, there are still people that need assistance. This type of aid often has to come through technology and the implementation of ideas. People with disabilities and the elderly usually require diligent monitoring and help to complete their daily tasks.
Autors: Iosif Papadakis Ktistakis;Nikolaos G. Bourbakis;
Appeared in: IEEE Potentials
Publication date: Jan 2017, volume: 36, issue:1, pages: 10 - 13
Publisher: IEEE
 
» Asymmetrical Operation Analysis for Dual Stator-Winding Induction Generator Variable Frequency AC Generating System With Unbalanced Loads
Abstract:
In this paper, the performance of the dual stator-winding induction generator (DWIG) variable frequency ac (VFAC) generating system with unbalanced loads is analyzed, and an asymmetrical operation analysis method based on a three-port load network model is proposed. This method has four key steps: (1) deriving the three-port load network model for three-phase four-line unbalanced loads; (2) establishing the positive sequence, negative sequence, and zero sequence equivalent circuits for the DWIG; (3) combining the above model and circuits together to obtain the system whole equivalent model; and (4) writing the corresponding equations and solving them. The experimental results and the calculation results are almost consistent, which proves that the proposed method is correct and valid, and the DWIG VFAC generating system with unbalanced loads has a good performance.
Autors: Feifei Bu;Shenglun Zhuang;Wenxin Huang;Ning Su;Yuwen Hu;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 52 - 59
Publisher: IEEE
 
» Asymptotically Stable Electromagnetic Shock Waves in Relativistic Plasmas
Abstract:
The behavior of electromagnetic (EM) waves in a relativistic plasma is investigated. The governing equations of such dynamical plasma system are derived from the basic fluid model equations, and the vector and electrostatic potential are analyzed using Maxwell’s equations. A system of first-order, ordinary but nonlinear differential equations, is obtained from the two coupled second-order differential equations. Numerical results are found using the fourth order Runge–Kutta method. It is seen that EM shock waves are emerged for subsonic case, and on the other hand, periodic oscillatory solution as well as asymptotically stable state is obtained for supersonic case. The present investigation is important to extrapolate in different plasma backgrounds, like laboratory and astroplasma environments, viz., in laboratory biomedicine, biophysics, genetic engineering, laboratory astrophysics, and at different stages of stellar evolution.
Autors: G. Mandal;U. N. Ghosh;M. Asaduzzaman;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2017, volume: 45, issue:1, pages: 148 - 153
Publisher: IEEE
 
» Atmospheric Correction of Landsat-8/OLI Imagery in Turbid Estuarine Waters: A Case Study for the Pearl River Estuary
Abstract:
Several methods have been proposed for atmospheric correction over turbid waters, including near-infrared (NIR) band based or short-wave infrared (SWIR) band-based where the signal in turbid waters can be assumed zero. Here, we adopt a new infrared extrapolation method to extend the existing turbid water atmospheric correction of the operational land imager (OLI) data on Landsat-8 platform. The atmospheric correction uses the extrapolated Rayleigh-corrected reflectance at NIR and SWIR bands to derive the ratios of NIR to SWIR and visible aerosol single-scattering contributions (aerosol epsilon). Taking the Pearl River Estuary as an example, the magnitude and spatial distribution of reflectance from OLI compare well with those of concurrent moderate resolution imaging spectroradiometer /Aqua based on SWIRE atmospheric correction method. The linear regression coefficients between the resampled OLI and Aqua data have demonstrated the proposed atmospheric correction method can provide robust and realistic reflectance. The advantages of the high spatial resolution made the OLI data a good source for applications in coastal and estuarine waters.
Autors: Haibin Ye;Chuqun Chen;Chaoyu Yang;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 252 - 261
Publisher: IEEE
 
» Auction-Based Coopetition Between LTE Unlicensed and Wi-Fi
Abstract:
Motivated by the recent efforts in extending long term evolution (LTE) to the unlicensed spectrum, we propose a novel spectrum sharing framework for the coopetition (i.e., cooperation and competition) between LTE and Wi-Fi in the unlicensed band. Basically, the LTE network can choose to work in one of the two modes: in the competition mode, it randomly accesses an unlicensed channel, and interferes with the Wi-Fi access point using the same channel; in the cooperation mode, it onloads the Wi-Fi users’ traffic in exchange for the exclusive access of the corresponding channel. We design a second-price reverse auction mechanism, which enables the LTE provider and the Wi-Fi access point owners (APOs) to effectively negotiate the operation mode. Specifically, the LTE provider is the auctioneer (buyer), and the APOs are the bidders (sellers) who compete to sell the rights of onloading the APOs’ traffic to the LTE provider. In Stage I of the auction, the LTE provider announces a reserve rate, which is the maximum data rate that it is willing to allocate to the APOs in the cooperation mode. In Stage II of the auction, the APOs submit their bids, which indicate the data rates that they would like the LTE provider to offer in the cooperation mode. We show that the auction involves allocative externalities, i.e., the cooperation between the LTE provider and one APO benefits other APOs who are not directly involved in this cooperation. We characterize the APOs’ unique equilibrium bidding strategies in Stage II, and analyze the LTE provider’s optimal reserve rate in Stage I. Numerical results show that our framework improves the payoffs of both the LTE provider and the APOs comparing with a benchmark scheme. In particular, our framework increases the LTE pro- ider’s payoff by 70% on average, when the LTE provider has a large throughput and a small data rate discounting factor. Moreover, our framework leads to a close-to-optimal social welfare under a large LTE throughput.
Autors: Haoran Yu;George Iosifidis;Jianwei Huang;Leandros Tassiulas;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jan 2017, volume: 35, issue:1, pages: 79 - 90
Publisher: IEEE
 
» Augmented reality: forget the glasses
Abstract:
In mid-2014, Magic Leap began teasing us with visions of realistic baby elephants playing in the palms of our hands, promising to soon unveil a mind-blowing augmented reality technology that would dramatically change the worlds of both entertainment and computing. Investors have ponied up an astounding US $1.39 billion so far to own a piece of this AR future, according to Crunchbase.
Autors: Tekla S. Perry;
Appeared in: IEEE Spectrum
Publication date: Jan 2017, volume: 54, issue:1, pages: 36 - 39
Publisher: IEEE
 
» Augmenting Human Intellect and Amplifying Perception and Cognition
Abstract:
This first installment of the new Human Augmentation department looks at various technologies designed to augment the human intellect and amplify human perception and cognition. Linking back to early work in interactive computing, Albrecht Schmidt considers how novel technologies can create a new relationship between digital technologies and humans.
Autors: Albrecht Schmidt;
Appeared in: IEEE Pervasive Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 6 - 10
Publisher: IEEE
 
» Automated Detection of Uninformative Frames in Pulmonary Optical Endomicroscopy
Abstract:
Significance: Optical endomicroscopy (OEM) is a novel real-time imaging technology that provides endoscopic images at a microscopic level. The nature of OEM data, as acquired in clinical use, gives rise to the presence of uninformative frames (i.e., pure-noise and motion-artefacts). Uninformative frames can comprise a considerable proportion (up to > 25%) of a dataset, increasing the resources required for analyzing the data (both manually and automatically), as well as diluting the results of any automated quantification analysis. Objective: There is, therefore, a need to automatically detect and remove as many of these uninformative frames as possible while keeping frames with structural information intact. Methods: This paper employs Gray Level Cooccurrence Matrix texture measures and detection theory to identify and remove such frames. The detection of pure-noise and motion-artefacts frames is treated as two independent problems. Results: Pulmonary OEM frame sequences of the distal lung are employed for the development and assessment of the approach. The proposed approach identifies and removes uninformative frames with a sensitivity of 93% and a specificity of 92.6%. Conclusion: The detection algorithm is accurate and robust in pulmonary OEM frame sequences. Conditional to appropriate model refinement, the algorithms can become applicable in other organs.
Autors: Antonios Perperidis;Ahsan Akram;Yoann Altmann;Paul McCool;Jody Westerfeld;David Wilson;Kevin Dhaliwal;Stephen McLaughlin;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jan 2017, volume: 64, issue:1, pages: 87 - 98
Publisher: IEEE
 
» Automatic Generation of Five-Axis Continuous Inspection Paths for Free-Form Surfaces
Abstract:
Continuous five-axis sweep scanning is an emerging technology for free-form surface inspection, which, unlike the traditional three-axis inspection that works in a point-by-point manner, keeps the stylus tip in constant contact with the surface during the scanning, and thus could tremendously improve the inspection efficiency. However, at present, it mostly depends on humans to plan a five-axis inspection path, which severely affects the potential use of this new technology. In this paper, we report a practical algorithm, which is able to automatically generate a five-axis inspection path for an arbitrary free-form surface. The crux of this algorithm is that the unique kinematic characteristics of the five-axis inspection machine are fully considered and utilized when a path is planned. As a direct result of this consideration and utilization, the inspection efficiency is tremendously increased, often 20–30 times better than an inspection path obtained by any traditional path planning algorithm that disregards the inspection machine itself. The experiments performed by us have fully validated this point.
Autors: Pengcheng Hu;Rong Zhang;Kai Tang;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2017, volume: 14, issue:1, pages: 83 - 97
Publisher: IEEE
 
» Automatic Identification of Space-Frequency Block Coding for OFDM Systems
Abstract:
Signal identification has emerged as an enabling technology for intelligent wireless communication systems with applications in military and commercial fields. One of recent trends in this research topic is to propose identification algorithms for multiple antenna (MA) systems with multi-carrier (MC) transmissions. The previously reported investigations are limited to space-time block code (STBC) systems with MC transmissions. However, practical systems include also space-frequency block code (SFBC) schemes with MC transmissions. In this paper, we develop and analyze an SFBC identification algorithm for MA orthogonal frequency-division multiplexing (OFDM) transmission for the first time in the literature. Analytical expressions for the time-domain properties of the Alamouti and spatial multiplexing SFBC-OFDM signals are derived as the basis of the identification process. The proposed algorithm is divided into two steps. The first step estimates the cross-correlation function of pairs of signals received from different antennas, while the second step employs a false-alarm based test for decision making. The proposed algorithm avoids the need for a priori knowledge of the modulation format, channel coefficients, signal-to-noise ratio (SNR) value, and the starting time of OFDM symbols. Simulation results show the ability of the proposed algorithm to provide an acceptable identification performance in the presence of transmission impairments, even at relatively low SNR values. These favorable results are achieved with acceptable computational cost.
Autors: Mohamed Marey;Octavia A. Dobre;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 117 - 128
Publisher: IEEE
 
» Automatic Video Remixing Systems
Abstract:
There has been a tremendous increase in the amount of user generated content (UGC), and many mobile devices are also equipped with sensors (magnetic compass, accelerometer, gyroscope, etc.). We present an automatic video remixing system (AVRS), which intelligently processes UGC in combination with sensor information. The system aims to generate a video remix with minimal user effort. We present sensor-based as well as sensor-less architectures of such a system. The sensor-based AVRS system involves certain architectural choices that meet the key system requirements (leverage user generated content, use sensor information, reduce end-user burden) and user experience requirements. Architecture adaptations are required if any of the operating parameters need to be constrained for real world deployment feasibility. We present sensor-less architecture adaptations that enable the usage of the automatic remixing logic in different operating scenarios. The challenge for these system adaptations is to improve the benefits for certain key performance parameters, while reducing the compromise for other parameters. Subsequently, two key sensor-less AVRS architecture adaptations (Cloud Remix System and Smartview system) are presented. We show that significant reduction in system complexity can be achieved when a smaller reduction in the user experience is allowed. Similarly, the system can also be optimized to reduce the need for other key requirement parameters such as storage and user density.
Autors: Sujeet Mate;Igor D. D. Curcio;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2017, volume: 55, issue:1, pages: 180 - 187
Publisher: IEEE
 
» Azimuth Motion Compensation With Improved Subaperture Algorithm for Airborne SAR Imaging
Abstract:
Conventional motion compensation (MOCO) under beam-center approximation is usually insufficient to correct severe track deviations for high-resolution synthetic aperture radar imaging. In this paper, a novel MOCO approach is developed for correction of the azimuth-variant motion errors by exploiting a precise angle-to-Doppler relationship within subapertures. The corruption from the residual motion errors to the angle-to-Doppler mapping is investigated and overcome by a compensation scheme of the scaled Fourier transform. Inheriting the high efficiency, the proposed azimuth MOCO approach has dramatically improved precision over the conventional subaperture MOCO method by reducing high side-lobe peaks of the point spread function. Extensive comparisons with other MOCO algorithms are given to show the superiority of the proposed algorithm. Moreover, real-data experiments are provided for a clear demonstration of our proposed approach.
Autors: Lei Zhang;Guanyong Wang;Zhijun Qiao;Hongxian Wang;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 184 - 193
Publisher: IEEE
 
» Backhaul-Aware User Association and Resource Allocation for Energy-Constrained HetNets
Abstract:
Growing attention has been paid to renewable- or hybrid-energy-powered heterogeneous networks (HetNets). In this paper, focusing on backhaul-aware joint user association and resource allocation for this type of HetNets, we formulate an online optimization problem to maximize the network utility reflecting proportional fairness. Since user association and resource allocation are tightly coupled not only on resource consumption of the base stations (BSs) but in the constraints of their available energy and backhaul as well, the closed-form solution is quite difficult to obtain. Thus, we solve the problem distributively by employing certain decomposition methods. Specifically, at first, by adopting the primal decomposition method, we decompose the original problem into a lower level resource-allocation problem for each BS and a higher level user-association problem. For the optimal resource allocation, we prove that a BS either assigns equal normalized resources or provides an equal long-term service rate to its served users. Then, the user-association problem is solved by the Lagrange dual decomposition method, and a completely distributed algorithm is developed. Moreover, applying results of the subgradient method, we demonstrate the convergence of the proposed distributed algorithm. Furthermore, to efficiently and reliably apply the proposed algorithm to the future wireless networks with an extremely dense BS deployment, we design a virtual user association and resource allocation scheme based on the software-defined networking architecture. Finally, numerical results validate the convergence of the proposed algorithm and the significant improvement on network utility, load balancing, and user fairness.
Autors: Qiaoni Han;Bo Yang;Guowang Miao;Cailian Chen;Xiaocheng Wang;Xinping Guan;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 580 - 593
Publisher: IEEE
 
» Balanced MSM-2DEG Varactors Based on AlGaN/GaN Heterostructure With Cutoff Frequency of 1.54 THz
Abstract:
AlGaN/GaN high-electron mobility transistor structures were utilized to fabricate metal–semiconductor–metal (MSM) two-dimensional electron gas (2DEG) varactors for application as a terahertz (THz) capacitive switch. By adopting an asymmetric MSM structure composed of nanoscale gates and micron-scale gates, the cutoff frequency of the MSM-2DEG varactors was dramatically improved, up to the THz range, by reducing series resistance. The balanced MSM-2DEG varactor, in which a nanoscale gate is sandwiched between two micron-scale gates exhibited a capacitance switching ratio ( of 2.64, a cutoff frequency of 1.54 THz, and a figure of merit of 4.06 THz.
Autors: Ji Hyun Hwang;Kye-Jeong Lee;Sung-Min Hong;Jae-Hyung Jang;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2017, volume: 38, issue:1, pages: 107 - 110
Publisher: IEEE
 
» Bandwidth and Cache Leasing in Wireless Information-Centric Networks: A Game-Theoretic Study
Abstract:
Information-centric networking (ICN) is a novel paradigm that aims at improving the performance of today's Internet by supporting caching and multicast content delivery on every network device. The main contribution of this paper is to propose a centralized strategy to stimulate third parties to jointly lease the unused bandwidth and storage available on wireless access points (APs) in an ICN. We formulate this problem as a combinatorial reverse auction run by a content provider (CP) willing to increase the number of users reached by its service. We show that the optimal allocation with partial coverage problem is NP-hard, provide greedy heuristics that guarantee the individual rationality and truthfulness properties, and compare their performance numerically. We evaluate the benefits of our proposed mechanisms in terms of the cost savings for the CP obtained by offloading its infrastructure through the caches and the reduced computational time to execute the allocation algorithms. We compare the results obtained in this centralized setting with those that can be observed when the mobile clients autonomously choose which AP they prefer to use, among those activated by the auction mechanism. We model this second scenario as a congestion game, showing that it exhibits the desired properties (i.e., existence and uniqueness of a Nash equilibrium) and by comparing its social welfare with the centralized case.
Autors: Michele Mangili;Fabio Martignon;Stefano Paris;Antonio Capone;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 679 - 695
Publisher: IEEE
 
» Bandwidth Enhancement of a Differential-Fed Equilateral Triangular Patch Antenna via Loading of Shorting Posts
Abstract:
A comprehensive study on the mechanism of bandwidth enhancement for an equilateral triangular microstrip patch antenna (MPA) under differential excitation is presented in this paper. Attributing to the way of differential excitation, the radiation directivity of TM11 mode in such a patch has been improved a lot, and field distributions for both TM10 and TM11 modes are found to be simultaneously excited for radiation. Next, two shorting posts are introduced to thisMPA so as to generate an additional mode, i.e., zero mode, which resonates in a frequency between TM10 and TM11 modes. With the proper arrangement of these three modes in proximity to each other, a wide bandwidth for radiation can be satisfactorily achieved. To demonstrate the validity of the proposed concept, a prototype antenna is finally designed and fabricated. As theoretically expected, the impedance bandwidth of the final designed patch antenna has been increased to 50.46% and the gain is around 6.5 dBi. Both simulated and measured results exhibit wide bandwidth and good performance of radiation.
Autors: Jianpeng Wang;Qianwen Liu;Lei Zhu;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2017, volume: 65, issue:1, pages: 36 - 43
Publisher: IEEE
 
» Bandwidth-Efficient Coded Modulation Schemes for Physical-Layer Network Coding with High-Order Modulations
Abstract:
This paper presents several soft decision iterative decoding schemes for physical-layer network coding (PNC) operated with coded modulation (CM) and bit-interleaved coded modulation (BICM). With respect to PNC operated with CM, we consider network coding-based channel decoding (NC-CD) and multi-user complete decoding (MUD-NC) for PNC decoding at the relay. Their BICM counterparts are XOR-based channel decoding (XOR-CD) and MUD-XOR, respectively. First, we show that, when the decoding is non-iterative, there is a gap between the BICM capacities of both XOR-CD and MUD-XOR under Gray mapping and the capacities of their CM counterparts, NC-CD, and MUD-NC. This is in contrast to the conventional point-to-point communication system, for which the BICM capacity with Gray mapping is known to be very close to the CM capacity, without the need for iterative decoding. Second, we investigate the error performance of iteratively decoded BICM XOR-CD and MUD-XOR. Extrinsic information transfer chart analysis and simulation results indicate that for these Gray-mapped BICM PNC systems, iterative decoding can achieve considerable gains over non-iterative decoding. Again, this is in contrast to the Gray-mapped BICM point-to-point communication system, for which iterative decoding provides little gain over non-iterative decoding. We further show that Gray mapping gives rise to best PNC rate for MUD-XOR and XOR-CD systems among several bits-to-symbol mappings under study. Overall, our results indicate that BICM PNC systems exhibit different decoding behavior from conventional BICM point-to-point systems. This paper serves as a first foray into the investigation of this issue.
Autors: Pingping Chen;Soung Chang Liew;Long Shi;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 147 - 160
Publisher: IEEE
 
» Banking on Availability
Abstract:
Combating the growing threat to banks of distributed denial-of-service attacks will demand more than keeping pace in a technological arms race; it will also require greater information sharing among banks and other cybersecurity entities.
Autors: Nir Kshetri;Jeffrey Voas;
Appeared in: Computer
Publication date: Jan 2017, volume: 50, issue:1, pages: 76 - 80
Publisher: IEEE
 
» Basis-Adaptive Sparse Polynomial Chaos Expansion for Probabilistic Power Flow
Abstract:
This paper introduces the basis-adaptive sparse polynomial chaos (BASPC) expansion to perform the probabilistic power flow (PPF) analysis in power systems. The proposed method takes advantage of three state-of-the-art uncertainty quantification methodologies reasonably: the hyperbolic scheme to truncate the infinite polynomial chaos (PC) series; the least angle regression (LARS) technique to select the optimal degree of each univariate PC series; and the Copula to deal with nonlinear correlations among random input variables. Consequently, the proposed method brings appealing features to PPF, including the ability to handle the large-scale uncertainty sources; to tackle the nonlinear correlation among the random inputs; to analytically calculate representative statistics of the desired outputs; and to dramatically alleviate the computational burden as of traditional methods. The accuracy and efficiency of the proposed method are verified through either quantitative indicators or graphical results of PPF on both the IEEE European Low Voltage Test Feeder and the IEEE 123 Node Test Feeder, in the presence of more than 100 correlated uncertain input variables.
Autors: Fei Ni;Phuong H. Nguyen;Joseph F. G. Cobben;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 694 - 704
Publisher: IEEE
 
» Battery-Powered Devices in WPCNs
Abstract:
Wireless powered communication networks are becoming an effective solution for improved self-sustainability of mobile devices. In this context, a hybrid access point transfers energy to a group of nodes, which use the harvested energy to perform computation or transmission tasks. While the availability of the wireless energy transfer mechanism opens up new frontiers, an appropriate choice of the network parameters (e.g., transmission powers, transmission duration, and amount of transferred energy) is required in order to achieve high performance. In this paper, we study the throughput optimization problem in a system composed of an access point, which recharges the batteries of two devices at different distances. In the literature, the main focus so far has been on slot-oriented optimization, in which all the harvested energy is used in the same slot in which it is harvested. However, this approach is strongly suboptimal, because it does not exploit the possibility to store the energy and use it at a later time. Thus, instead of considering the slot-oriented case, we address the long-term maximization. This assumption greatly increases the optimization complexity, as it requires to consider, e.g., the channel state statistics and the batteries evolution. Our objective is to find the best scheduling scheme, both for the energy transferred by the access point and for the data sent by the two nodes. We discuss how to perform the maximization with optimal as well as approximate techniques and show that the slot-oriented policies proposed so far are strongly suboptimal in the long run.
Autors: Alessandro Biason;Michele Zorzi;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 216 - 229
Publisher: IEEE
 
» Bayesian Approach in the Modal Analysis of Electromechanical Oscillations
Abstract:
This paper presents a Bayesian approach for identifying the modal parameters (i.e., frequency, damping ratio, and modal excitation) of electromechanical modes. The proposed approach identifies the modal parameters and calculates their uncertainty using ambient phasor measurement unit (PMU) measurements from a power system. The method is applied in the frequency domain on a selected frequency band, which significantly simplifies the identification. The performance of the method is studied with simulated data from the IEEE New England test system and the Nordic power system simulation model. In addition, measured PMU data from the Nordic power system are used. The results indicate that the modal parameters of electromechanical modes can be identified reliably and their identification uncertainty can be fundamentally calculated using the proposed method. Thus, the Bayesian approach is a promising identification method for wide-area monitoring of electromechanical oscillations.
Autors: Janne Seppänen;Siu-Kui Au;Jukka Turunen;Liisa Haarla;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 316 - 325
Publisher: IEEE
 
» Behind the Scenes of IEEE 1683: A Look into the Creation of a Standard
Abstract:
Electrical equipment installations and system designs that comply with well-known consensus standards and national codes will meet or exceed minimum guidelines for safety and reliability. However, many within the industry believe that further attention should be paid to the principles of safety by design and prevention through design. In response, IEEE Standard 1683 [1], has been written to address electrical safety for low-voltage motor control centers (MCs), and similar standards are in development for other types of equipment. IEEE 1683 is the first IEEE standard developed to specifically address equipment design, selection, and installation practices with an emphasis on methods to reduce exposure to shock and arc-flash hazards. This article summarizes the history and reasons that led to the development of IEEE Standard 1683 and provides an introduction to its application for safer, low-voltage MCs.
Autors: Marcelo E. Valdes;Rachel M. Bugaris;Craig M. Wellman;
Appeared in: IEEE Industry Applications Magazine
Publication date: Jan 2017, volume: 23, issue:1, pages: 26 - 33
Publisher: IEEE
 
» Beijing Converters: Bridge Converters With a Capacitor Added to Reduce Leakage Currents, DC-Bus Voltage Ripples, and Total Capacitance Required
Abstract:
Isolation transformers and bulky electrolytic capacitors are often used in power electronic converters to reduce leakage currents and voltage ripples but this leads to low power density and reduced reliability. In this paper, an auxiliary capacitor is added to the widely used conventional full-bridge converter to provide a path for, and hence significantly reduce, the leakage current. The operation of the full-bridge converter is split into the operation of a half-bridge converter and a dc–dc converter so that the ripple energy can be diverted from the dc-bus capacitor to the auxiliary capacitor. Hence, the dc-bus capacitor can be significantly reduced while maintaining very low voltage ripples on the dc bus because it is only required to filter out switching ripples. The auxiliary capacitor is designed to allow high voltage ripples because its voltage is not supplied to any load. Accordingly, the auxiliary capacitor can also be very small as well. As a result, the total required capacitance becomes very small. The reduction ratio of the total capacitance is significant, which makes it cost-effective to use film capacitors instead of electrolytic capacitors. The proposed converters can be also operated as an inverter without any restriction on power factor because the adopted four switches are all bidirectional in terms of power flow. Experimental results for both rectification and inversion modes are presented to demonstrate the performance of the proposed converter in reducing the ripples, the leakage currents, and the total capacitance needed, with comparison to the conventional bridge converter without the auxiliary capacitor.
Autors: Qing-Chang Zhong;Wen-Long Ming;Wanxin Sheng;Yongsheng Zhao;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 325 - 335
Publisher: IEEE
 
» Benchmark Models for the Analysis and Control of Small-Signal Oscillatory Dynamics in Power Systems
Abstract:
This paper summarizes a set of six benchmark systems for the analysis and control of electromechanical oscillations in power systems, recommended by the IEEE Task Force on Benchmark Systems for Stability Controls of the Power System Dynamic Performance Committee. The benchmark systems were chosen for their tutorial value and particular characteristics leading to control the system design problems relevant to the research community. For each benchmark, the modeling guidelines are provided, along with eigenvalues and time-domain results produced with at least two simulation softwares, and one possible control approach is provided for each system as well. Researchers and practicing engineers are encouraged to use these benchmark systems when assessing new oscillation damping control strategies.
Autors: C. Canizares;T. Fernandes;E. Geraldi;L. Gerin-Lajoie;M. Gibbard;I. Hiskens (TF Past Chair);J. Kersulis;R. Kuiava;L. Lima;F. DeMarco;N. Martins;B. C. Pal;A. Piardi;R. Ramos (TF Chair);J. dos Santos;D. Silva;A. K. Singh;B. Tamimi;D. Vowles;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 715 - 722
Publisher: IEEE
 
» Benchmarking of Mask Fracturing Heuristics
Abstract:
Aggressive resolution enhancement techniques such as inverse lithography (ILT) often lead to complex, nonrectilinear mask shapes which make mask writing extremely slow and expensive. To reduce shot count of complex mask shapes, mask writers allow overlapping shots, due to which the problem of fracturing mask shapes with minimum shot count is NP-hard. The need to account for e-beam proximity effect makes mask fracturing even more challenging. Although a number of fracturing heuristics have been proposed, there has been no systematic study to analyze the quality of their solutions. In this paper, we first propose a method to generate tight upper and lower bounds for actual ILT mask shapes by formulating mask fracturing as an integer linear program and solving it using branch and price. Since the integer program requires significant computational resources to compute reasonable bounds, we propose a new method to generate benchmarks with known optimal solutions, that can be used to evaluate the suboptimality of mask fracturing heuristics. To make the generated benchmark shapes realistic, we further propose a novel automated benchmark generation method that takes any ILT shape as input and returns a benchmark shape which looks similar to the input shape and for which the optimal fracturing solution is known. Using these methods, we compare the suboptimality of four mask fracturing heuristics. Our results show that even a state-of-the-art prototype (version of) capability within a commercial EDA tool for e-beam mask shot decomposition can be suboptimal by as much as for real ILT shapes and by for generated benchmarks.
Autors: Tuck-Boon Chan;Puneet Gupta;Kwangsoo Han;Abde Ali Kagalwalla;Andrew B. Kahng;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jan 2017, volume: 36, issue:1, pages: 170 - 183
Publisher: IEEE
 
» Bending Vector Sensor Based on a Pair of Opposite Tilted Long-Period Fiber Gratings
Abstract:
A novel optical fiber grating vector bending sensor head is demonstrated. The sensor head is composed by two cascaded 6° tilted long period fiber gratings, which are separated by a distance . The asymmetric characteristics of the proposed sensor originate from two tilted long period gratings with angles placed oppositely and asymmetric exposure of the CO2 laser pulses. Two selected dips shift toward each other when the sensor head is bent. The interval between the two dips is used for improving the sensitivity of curvature measurement and further decreasing the temperature crosstalk. For the curvature range from 0.5 to 2 , the bending sensitivities reach −15.4935 and 15.2852 nm/ for the opposite bending directions. The temperature sensitivity of the sensor is one third of the normal long period fiber grating.
Autors: Yan-Ping Li;Wei-Gang Zhang;Song Wang;Lei Chen;Yan-Xin Zhang;Biao Wang;Tie-Yi Yan;Xin-Yu Li;Wei Hu;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:2, pages: 224 - 227
Publisher: IEEE
 
» Beyond 5G Vision for IOLITE Community
Abstract:
Connecting a massive number of sensors and actuators with energy and transmission constraints is only possible by providing a reliable connection despite the increase in data traffic due to the Internet of Things, and by guaranteeing a maximum end-to-end delay for applications with real-time constraints. Next generation network architectures need to satisfy these two requirements while connecting IoT sources producing data at massive scales to cloud resources that provide the capability to process and store this data. For this reason, realization of IoT in next generation cellular networks faces the problem of delivering cloud services over the network to things that are placed anywhere. In this study, we explain how the technologies envisioned for next generation networks can respond to the challenge of realizing IoT over a use case prepared for the IoT smart home platform called IOLITE. We start by discussing capacity requirements and focus on network densification as a promising solution method. The challenges of network densification can be overcome by integrating the technological enablers such as SDN, C-RAN, SON, and mobile edge computing. For this reason, we provide a thorough survey on the state of the art in integrating these enablers for a flexible network architecture at all network segments. Finally, we discuss how the needs of the IOLITE community use case scenario can be satisfied by implementing a service- centric abstraction layer on top of a flexible infrastructure for beyond 5G IoT applications.
Autors: Doruk Sahinel;Cem Akpolat;Manzoor A. Khan;Fikret Sivrikaya;Sahin Albayrak;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2017, volume: 55, issue:1, pages: 41 - 47
Publisher: IEEE
 
» Beyond Overlay: Reaping Mutual Benefits for Primary and Secondary Networks Through Node-Level Cooperation
Abstract:
Existing spectrum sharing paradigms have set clear boundaries between the primary and secondary networks. There is either no or very limited node-level cooperation between the primary and secondary networks. In this paper, we develop a new and bold spectrum-sharing paradigm beyond the state of the art for future wireless networks. We explore network cooperation as a new dimension for spectrum sharing between the primary and secondary users. Such network cooperation can be defined as a set of policies under which different degrees of cooperation are to be achieved. The benefits of this paradigm are numerous, as they allow integrating resources from two networks. There are many possible node-level cooperation policies that one can employ under this paradigm. For the purpose of performance study, we consider a specific policy called United cooperation of Primary and Secondary (UPS) networks. UPS allows a complete cooperation between the primary and secondary networks at the node level to relay each other's traffic. As a case study, we consider a problem with the goal of supporting the rate requirement of the primary network traffic while maximizing the throughput of the secondary sessions. For this problem, we develop an optimization model and formulate a combinatorial optimization problem. We also develop an approximation solution based on a piece-wise linearization technique. Simulation results show that UPS offers significantly better throughput performance than that under the interweave paradigm.
Autors: Xu Yuan;Yi Shi;Xiaoqi Qin;Y. Thomas Hou;Wenjing Lou;Sastry Kompella;Scott F. Midkiff;Jeffrey H. Reed;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 2 - 15
Publisher: IEEE
 
» Big data vs. bad air [News]
Abstract:
In mid-October 2016, officials from China's Ministry of Environmental Protection counted five illegal trash-burning sites and hundreds of thousands of vehicles exceeding emission standards in Beijing alone. For the first time since last winter’s pollution high season, city officials issued a yellow air-quality alert, which required shutting down power plants and reining in Beijing’s frenetic factories and road traffic. If this winter is anything like past winters, the city will have to pull out the yellow card again—and may even have to reach for its red card.
Autors: Lucas Laursen;
Appeared in: IEEE Spectrum
Publication date: Jan 2017, volume: 54, issue:1, pages: 14 - 16
Publisher: IEEE
 
» Bilevel Feature Extraction-Based Text Mining for Fault Diagnosis of Railway Systems
Abstract:
A vast amount of text data is recorded in the forms of repair verbatim in railway maintenance sectors. Efficient text mining of such maintenance data plays an important role in detecting anomalies and improving fault diagnosis efficiency. However, unstructured verbatim, high-dimensional data, and imbalanced fault class distribution pose challenges for feature selections and fault diagnosis. We propose a bilevel feature extraction-based text mining that integrates features extracted at both syntax and semantic levels with the aim to improve the fault classification performance. We first perform an improved statistics-based feature selection at the syntax level to overcome the learning difficulty caused by an imbalanced data set. Then, we perform a prior latent Dirichlet allocation-based feature selection at the semantic level to reduce the data set into a low-dimensional topic space. Finally, we fuse fault features derived from both syntax and semantic levels via serial fusion. The proposed method uses fault features at different levels and enhances the precision of fault diagnosis for all fault classes, particularly minority ones. Its performance has been validated by using a railway maintenance data set collected from 2008 to 2014 by a railway corporation. It outperforms traditional approaches.
Autors: Feng Wang;Tianhua Xu;Tao Tang;MengChu Zhou;Haifeng Wang;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2017, volume: 18, issue:1, pages: 49 - 58
Publisher: IEEE
 
» BiRank: Towards Ranking on Bipartite Graphs
Abstract:
The bipartite graph is a ubiquitous data structure that can model the relationship between two entity types: for instance, users and items, queries and webpages. In this paper, we study the problem of ranking vertices of a bipartite graph, based on the graph's link structure as well as prior information about vertices (which we term a query vector). We present a new solution, BiRank, which iteratively assigns scores to vertices and finally converges to a unique stationary ranking. In contrast to the traditional random walk-based methods, BiRank iterates towards optimizing a regularization function, which smooths the graph under the guidance of the query vector. Importantly, we establish how BiRank relates to the Bayesian methodology, enabling the future extension in a probabilistic way. To show the rationale and extendability of the ranking methodology, we further extend it to rank for the more generic -partite graphs. BiRank's generic modeling of both the graph structure and vertex features enables it to model various ranking hypotheses flexibly. To illustrate its functionality, we apply the BiRank and TriRank (ranking for tripartite graphs) algorithms to two real-world applications: a general ranking scenario that predicts the future popularity of items, and a personalized ranking scenario that recommends items of interest to users. Extensive experiments on both synthetic and real-world datasets demonstrate BiRank's soundness (fast convergence), efficiency (linear in the number of graph edges), and effectiveness (achieving state-of-the-art in the two real-world tasks).
Autors: Xiangnan He;Ming Gao;Min-Yen Kan;Dingxian Wang;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Jan 2017, volume: 29, issue:1, pages: 57 - 71
Publisher: IEEE
 
» Blessing of Dimensionality: Recovering Mixture Data via Dictionary Pursuit
Abstract:
This paper studies the problem of recovering the authentic samples that lie on a union of multiple subspaces from their corrupted observations. Due to the high-dimensional and massive nature of today’s data-driven community, it is arguable that the target matrix (i.e., authentic sample matrix) to recover is often low-rank. In this case, the recently established Robust Principal Component Analysis (RPCA) method already provides us a convenient way to solve the problem of recovering mixture data. However, in general, RPCA is not good enough because the incoherent condition assumed by RPCA is not so consistent with the mixture structure of multiple subspaces. Namely, when the subspace number grows, the row-coherence of data keeps heightening and, accordingly, RPCA degrades. To overcome the challenges arising from mixture data, we suggest to consider LRR in this paper. We elucidate that LRR can well handle mixture data, as long as its dictionary is configured appropriately. More precisely, we mathematically prove that LRR can weaken the dependence on the row-coherence, provided that the dictionary is well-conditioned and has a rank of not too high. In particular, if the dictionary itself is sufficiently low-rank, then the dependence on the row-coherence can be completely removed. These provide some elementary principles for dictionary learning and naturally lead to a practical algorithm for recovering mixture data. Our experiments on randomly generated matrices and real motion sequences show promising results.
Autors: Guangcan Liu;Qingshan Liu;Ping Li;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2017, volume: 39, issue:1, pages: 47 - 60
Publisher: IEEE
 
» Block Kriging With Measurement Errors: A Case Study of the Spatial Prediction of Soil Moisture in the Middle Reaches of Heihe River Basin
Abstract:
Block kriging (BK) is a common method of predicting the true value at the pixel scale when validating remote sensing retrieval products. However, measurement errors (MEs) increase the prediction uncertainty. In this letter, an extended interpolation technique—BK with MEs (BKMEs)—is developed. The properties of BKME are proven through derivation and demonstrated in a case study of soil moisture (SM) upscaling. Three prediction scenarios—one without MEs (BK), BK with homogeneous MEs (BKHOME), and BK with heterogeneous MEs (BKHEME)—are considered for the upscaling of SM data observed by a distributed wireless sensor network, and the results are compared. Both BK and BKHOME yield the same upscaling results, which differ from those of BKHEME, and the prediction results of BKHEME show less bias than those of the other scenarios. Because both BKHOME and BKHEME consider MEs, their prediction results show smaller kriging variances than do the BK results. Three primary conclusions are drawn. The first is that the optimal kriging coefficients assigned to the observations are affected not only by spatial distance but also by the MEs when the MEs of the samples are unequal. The second is that when the MEs are equal, it may not be necessary to consider the MEs to predict the value for an unobserved location. The third is that although the prediction uncertainty can be reduced by considering MEs, it is more meaningful to consider unequal MEs than equal MEs in the prediction process. BKME is an advanced upscaling method that achieves improved prediction accuracy by considering MEs.
Autors: Jian Kang;Rui Jin;Xin Li;Yang Zhang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jan 2017, volume: 14, issue:1, pages: 87 - 91
Publisher: IEEE
 
» Boeing and spaceX vie to fly Astronauts [Top Tech 2017]
Abstract:
When Chris Ferguson commanded the final space shuttle mission in July 2011, he and his crew members left behind something on the International Space Station: a small American flag that had flown on the first shuttle mission three decades earlier. “It will hopefully maintain a position of honor until the next vehicle launched from U.S. soil brings U.S. astronauts up to dock with the space station,” Ferguson explained in a call with President Obama during the mission.
Autors: Jeff Foust;
Appeared in: IEEE Spectrum
Publication date: Jan 2017, volume: 54, issue:1, pages: 46 - 49
Publisher: IEEE
 
» Book Reviews
Abstract:
Autors: Piotr Borylo;Piotr Cholda;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2017, volume: 55, issue:1, pages: 10 - 11
Publisher: IEEE
 
» Bounds for Low Probability of Detection for Underwater Acoustic Communication
Abstract:
Most military underwater activities require stealth operations, and hydroacoustic transmissions might temper the mission. For this reason, military underwater acoustic transmission aims for low probability of detection (LPD). LPD communication systems are characterized by low transmission power and reception at low signal-to-noise power ratio (SNPR). As a side effect, LPD decreases acoustic noise pollution. In this paper, we study the LPD capability of underwater acoustic communication (UWAC) systems. We consider an interceptor with target false alarm and detection probabilities and a legitimate receiver with required detection and packet error probabilities. For the interceptor, we focus on an energy detector and calculate the minimal SNPR which satisfies its required performance. For the legitimate communication link, we consider spread-spectrum signaling with several modulation techniques, and calculate the minimal required SNPR to allow reliable detection and decoding of a data packet. Based on these minimal SNPR terms and using bounds on power attenuation in the channel, we quantify the LPD capability of the system and analyze the effect of channel and communication parameters. We also present results from a sea trial conducted in the Saanich Inlet off the coast of Vancouver Island, where we conducted LPD experiments for different transmission powers and carrier frequencies. We provide bounds for the minimal bandwidth and maximal transmission rate for LPD communication. Our results also show that LPD UWAC performs better in shallow and warm water, and for transmission at low carrier frequencies.
Autors: Roee Diamant;Lutz Lampe;Emmett Gamroth;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Jan 2017, volume: 42, issue:1, pages: 143 - 155
Publisher: IEEE
 
» Bowers & Wilkins P9 signature headphones [Resources_Review]
Abstract:
These are odd times for busy audiophiles. You might have a US $5,000 system at home, but chances are it’s gathering dust. Yet music remains a big part of your life—it’s just that these days it’s mostly coming to you from your phone. Well, time to embrace the trend and get the best experience you can. The new Bowers & Wilkins P9 Signature headphones are a good place to start.
Autors: Glenn Zorpette;
Appeared in: IEEE Spectrum
Publication date: Jan 2017, volume: 54, issue:1, pages: 22 - 22
Publisher: IEEE
 
» Braking Torque Due to Cross Magnetization in Unsaturated IPM BLDC Machines and Its Mitigation
Abstract:
Cross magnetization (CM) is an inevitable phenomenon in electrical machines. It is more prominent in interior permanent magnet (IPM) brushless dc (BLDC) machines. This is because PMs demagnetize in overloaded and saturated conditions. It leads to cross coupling between the direct and quadrature-axes quantities, and a decrease in the resultant air-gap flux-density distribution under saturated conditions. In this paper, it is shown that CM leads to braking torque even in unsaturated IPM BLDC machines. Furthermore, the effect of CM on flux linkage, electromotive force, and dynamic torque is presented. Its mitigation using suitable selection of slot–pole combination is presented. It is observed that odd slot–pole combinations are least affected, and even slot–pole combinations are severely affected by CM. Furthermore, it is found that the overlap area of rotor pole arc with the stator pole arc influences the severity of CM, more particularly in fractional slot–pole combination machines. To verify these claims, finite-element method is used for modeling and analyzing various slot–pole combinations of a spoke-type IPM BLDC motor. The results obtained from these simulations are validated with a fabricated reference prototype, which support the claims.
Autors: S. Sashidhar;B. G. Fernandes;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 9
Publisher: IEEE
 
» Breast Ultrasound Technology and Performance Evaluation of Ultrasound Equipment: B-Mode
Abstract:
Ultrasound (US) has become increasingly important in imaging and image-guided interventional procedures. In order to ensure that the imaging equipment performs to the highest level achievable and thus provides reliable clinical results, a number of quality control (QC) methods have been developed. Such QC is increasingly required by accrediting agencies and professional organizations; however, these requirements typically do not include detailed procedures for how the tests should be performed. In this paper, a detailed overview of QC methods for general and breast US imaging using computer-based objective methods is described. The application of QC is then discussed within the context of a common clinical application (US-guided needle biopsy) as well as for research applications, where QC may not be mandated, and thus is rarely discussed. The implementation of these methods will help in finding early stage equipment faults and in optimizing image quality, which could lead to better detection and classification of suspicious findings in clinical applications, as well as improving the robustness of research studies.
Autors: Elisabetta Sassaroli;Andrea Scorza;Calum Crake;Salvatore Andrea Sciuto;Mi-Ae Park;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Jan 2017, volume: 64, issue:1, pages: 192 - 205
Publisher: IEEE
 
» Bridge Displacements Monitoring Using Space-Borne X-Band SAR Interferometry
Abstract:
The development of interferometric methodologies for deformation monitoring that are able to deal with long time series of synthetic aperture radar (SAR) images made the detection of seasonal effects possible by decomposing the differential SAR phase. In the case of monitoring of man-made structures, particularly bridges, the use of high-resolution X-band SAR data allows the determination of three major components with significant influence on the SAR phase: the linear deformation trend, the height of structures over terrain, and the thermal expansion. In the case of stable metallic or (reinforced) concrete structures, this last effect can reach a magnitude comparable to or even exceeding the other phase components. In this review, we present two case studies that confirm the feasibility of InSAR techniques for bridge deformation monitoring and our original approach to refine the thermal expansion component.
Autors: Milan Lazecky;Ivana Hlavacova;Matus Bakon;Joaquim J. Sousa;Daniele Perissin;Gloria Patricio;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 205 - 210
Publisher: IEEE
 
» Bristol Ridge: A 28-nm $times$ 86 Performance-Enhanced Microprocessor Through System Power Management
Abstract:
Power management techniques can be effective at extracting more performance and energy efficiency out of mature systems on chip (SoCs). For instance, the peak performance of microprocessors is often limited by worst case technology (Vmax), infrastructure (thermal/electrical), and microprocessor usage assumptions. Performance/watt of microprocessors also typically suffers from guard bands associated with the test and binning processes as well as worst case aging/lifetime degradation. Similarly, on multicore processors, shared voltage rails tend to limit the peak performance achievable in low thread count workloads. In this paper, we describe five power management techniques that maximize the per-part performance under the before-mentioned constraints. Using these techniques, we demonstrate a net performance increase of up to 15% depending on the application and TDP of the SoC, implemented on “Bristol Ridge,” a 28-nm CMOS, dual-core x86 accelerated processing unit.
Autors: Sriram Sundaram;Aaron Grenat;Samuel Naffziger;Tom Burd;Stephen Kosonocky;Steve Liepe;Ravinder Rachala;Miguel Rodriguez;Michael Austin;Sriram Sambamurthy;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2017, volume: 52, issue:1, pages: 89 - 97
Publisher: IEEE
 
» Broadband Carpet Cloak Designed Using Nanocomposite Metamaterials for 3–5-μm Wavelength Range
Abstract:
In this paper, a broadband carpet cloak using nanocomposite layers to operate in whole 3–5-μm wavelength band is designed successfully. For this purpose, spherical nanometals or doped semiconductors with desired plasma frequency are proposed. In this way, the refractive index of the cloak as an analytic function is considered by optical conformal mapping. In a two-dimensional structure, we approximated the obtained refractive index inside each pixel to be constant. Each pixel is considered as an effective medium that possesses nanoparticles with desired plasma frequency. Therefore, plasma frequency of nanoparticles should be adjusted proportional to the desired value of refractive index in each two-dimensional pixels, which is approximated to be constant (two-dimensional layers approximation). The cloak region is compacted for broadband performance. To compact the cloak region, refractive index values should be greater than 1 and realization of these required values is possible by designing nonresonant structures.
Autors: Saba Khosravi;Ali Rostami;Mahboubeh Dolatyari;Ghasem Rostami;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jan 2017, volume: 16, issue:1, pages: 44 - 48
Publisher: IEEE
 
» Buffer-Aided Non-Orthogonal Multiple Access Relaying Systems in Rayleigh Fading Channels
Abstract:
Non-orthogonal multiple access (NOMA) is a promising technology in future communication systems. In this paper, we propose a buffer-aided NOMA relaying system, which consists of a source, a relay, and two destinations. In the relaying system, the relay helps the source transmit packets to two destinations simultaneously using NOMA scheme. We theoretically derive outage probabilities of source-to-relay link and relay-to-destinations links considering two scenarios that the relay does and does not know the channel state information (CSI) from itself to two destinations. When the relay knows CSI, the obtained outage probability of relay-to-destinations links involves integration operation. Thus, we derive an upper bound and two lower bounds. Simulation results demonstrate that two lower bounds approach exact outage probability at low and high signal-to-noise ratios, respectively. We also propose a relay decision scheme for the buffer-aided NOMA relaying system. Based on the obtained system outage probability, we theoretically derive the diversity order. It is found that no matter whether the relay knows CSI or not, the diversity order of 2 can be achieved when the buffer size is larger than or equal to 3.
Autors: Qi Zhang;Zijun Liang;Quanzhong Li;Jiayin Qin;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 95 - 106
Publisher: IEEE
 
» Building on the Past with an Eye to the Future [President's Column]
Abstract:
Presents the President's message for this issue of the publication.
Autors: Dylan Williams;
Appeared in: IEEE Microwave Magazine
Publication date: Jan 2017, volume: 18, issue:1, pages: 14 - 14
Publisher: IEEE
 
» Building the World's Longest Heated Pipeline—A Technology Application Review
Abstract:
The world depends on oil for much of its energy needs and global demand for oil is forecast to increase significantly in the future as countries such as China and India continue to develop Much of the world's conventional or “easy” oil sources have already been located and developed, so oil companies are increasingly turning to more difficult nonconventional oil sources that require innovative technology to be developed successfully. Often it is the physical properties of the oil that define it as nonconventional, such as being unusually heavy or viscous or containing a high percentage of wax, presenting difficult flow assurance and transportation problems that must be overcome. This paper describes the development of an Indian oil field containing a kind of oil so waxy that it is solid at ambient temperatures, requiring the construction of the world's longest heated pipeline to transport the waxy crude more than 600 km from a remote desert location to a coastal refining hub. The topics covered include the evaluation of various transportation solutions, selection of a skin effect heating system, thermal insulation, power sources and distribution, challenges associated with the design and construction, and lessons learnt that could enhance the safety and reliability of future projects.
Autors: Marty Hamill;Franco Chakkalakal;Jim Beres;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 709 - 717
Publisher: IEEE
 
» Calculation of PM Eddy Current Loss in IPM Machine Under PWM VSI Supply With Combined 2-D FE and Analytical Method
Abstract:
A hybrid method combining 2-D finite-element (FE) method and analytical model is proposed for permanent magnet (PM) eddy current loss calculation in interior PM machines under pulsewidth modulation (PWM) voltage source inverter (VSI) supply, in which the PM eddy current reaction effect and PM axial segmentation are taken into consideration. First, the 2-D time-stepping (TS) FE analysis results considering and neglecting PM eddy current under PWM VSI supply are compared so that the cause of PM eddy current loss, the increase of high-order armature current components due to PM eddy current effect, and the decrease of the high-order components in average flux density due to leakage flux are revealed. Second, an analytical model for PM eddy current loss calculation using voltage input is deduced with the average flux density as input and a leakage flux factor is introduced in the model to meet the real case in PM machine. Moreover, the 3-D frequency FE analysis is used to verify the derived model. Third, the ratio between the average flux density and the imposed flux density is defined as a key parameter to reflect the PM eddy current reaction effect quantitatively, for both 2-D and 3-D cases. A functional relationship is established to describe the variation of the average flux density with and without considering the PM eddy current, where the parameter is obtained with nonlinear fitting of the 2-D FEA results. At last, the calculation procedure of the hybrid method is presented and a flux-concentrating field-modulated PM machine is taken as an example for calculation. The results are verified by an FE analysis. The proposed method is more efficient compared with the 3-D TS FE method while maintaining rather good accuracy.
Autors: Ming Cheng;Sa Zhu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 12
Publisher: IEEE
 
» Call Blocking Probability and Effective Throughput for Call Admission Control of CoMP Joint Transmission
Abstract:
Coordinated multipoint transmission (CoMP) with the joint transmission (JT) scheme is employed in cellular networks to improve data rate and cell-edge throughput and/or to increase system throughput. In CoMP-JT, since the user equipment (UE) is capable of receiving the desired signal from an adjacent cell, as well as from its serving cell, it can achieve an improved signal-to-interference ratio (SIR). However, this scheme entails exhaustion of resources in serving base stations. In this paper, we propose a call admission control scheme (CAC) to improve the performance of CoMP-JT-based cellular systems. In this CAC scheme, the CoMP-JT technique is applied to UEs located near the edge of a cell. To establish an analytical model for CoMP-JT-based cellular systems, we introduce a model for traffic analysis using a 2-D Markov chain and approximate the computation of the power sum of multiple lognormal random components in a multicell environment. Performances of CoMP-JT-based cellular systems are evaluated with respect to two quality-of-service (QoS) constraints pertaining to call-blocking and outage probabilities, respectively, from the network-layer and the physical-layer perspectives. We first measure the resource utilization and call blocking probability for the downlink resources for various offered loads in the cell. Based on that, we obtain the outage probability and effective throughput of the system. The analytical results are compared with computer simulations. Finally, we consider the dynamic point selection (DPS) scheme that is a modified version of the JT scheme, in which some resources of adjacent cells are muted.
Autors: Seung-Yeon Kim;Choong-Ho Cho;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 622 - 634
Publisher: IEEE
 
» Capacity of the Two-Hop Relay Channel With Wireless Energy Transfer From Relay to Source and Energy Transmission Cost
Abstract:
In this paper, we investigate a communication system comprised of an energy harvesting (EH) source, which harvests radio frequency (RF) energy from an out-of-band full-duplex relay node and exploits this energy to transmit data to a destination node via the relay node. We assume two scenarios for the battery of the EH source. In the first scenario, we assume that the EH source is not equipped with a battery and thereby cannot store energy. As a result, the RF energy harvested during one symbol interval can only be used in the following symbol interval. In the second scenario, we assume that the EH source is equipped with a battery having unlimited storage capacity in which it can store the harvested RF energy. As a result, the RF energy harvested during one symbol interval can be used in any of the following symbol intervals. For both system models, we derive the channel capacity subject to an average power constraint at the relay and an additional energy transmission cost at the EH source. We compare the derived capacities to the achievable rates of several benchmark schemes. Our results show that using the optimal input distributions at both the EH source and the relay is essential for high performance. Moreover, we demonstrate that neglecting the energy transmission cost at the source can result in a severe overestimation of the achievable performance.
Autors: Nikola Zlatanov;Derrick Wing Kwan Ng;Robert Schober;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 647 - 662
Publisher: IEEE
 
» Capacity-Approaching TQC-LDPC Convolutional Codes Enabling Power-Efficient Decoders
Abstract:
In this paper, we develop a new capacity-approaching code, namely, parallel-concatenated (PC)-Low Density Parity Check (LDPC) convolutional code that is based on the parallel concatenation of trellis-based quasi-cyclic LDPC (TQC-LDPC) convolutional codes. The proposed PC-LDPC convolutional code can be derived from any QC-LDPC block code by introducing the trellis-based convolutional dependency to the code. The capacity-approaching PC-LDPC convolutional codes are encoded through parallel concatenated trellis-based QC recursive systematic convolutional (RSC) encoder (namely, QC-RSC encoder) that is also proposed in this paper. The proposed PC-LDPC convolutional code and the associated encoder retain a fine input granularity on the order of the lifting factor of the underlying block code. We also describe the corresponding trellis-based QC maximum a posteriori probability (namely, QC-MAP) decoder that efficiently decodes the PC-LDPC convolutional code. Performance and hardware implementation results show that the PC-LDPC convolutional codes with the QC-MAP decoder have two times lower complexity for a given bit-error-rate (BER), signal-to-noise ratio, and data rate, than conventional QC-LDPC block codes and LDPC convolutional codes. Moreover, the PC-LDPC convolutional code with the QC-MAP decoder outperforms the conventional QC-LDPC block codes by more than 0.5 dB for a given BER, complexity, and data rate and approaches Shannon capacity limit with a gap smaller than 1.25 dB. This low decoding complexity and the fine granularity make it feasible to efficiently implement the proposed capacity-approaching PC-LDPC convolutional code and the associated trellis-based QC-MAP decoder in next generation ultra-high data rate mobile systems.
Autors: Eran Pisek;Dinesh Rajan;Shadi Abu-Surra;Joseph R. Cleveland;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 1 - 13
Publisher: IEEE
 
» CarrierMix: How Much Can User-side Carrier Mixing Help?
Abstract:
Energy consumption for cellular communication is increasingly gaining importance in smartphone battery lifetime as the bandwidth of wireless communication and the demand for mobile traffic increase. For energy-efficient cellular communication, we tackle two energy characteristics of cellular networks: (1) transmission energy highly varies upon channel condition, and (2) transmission of a packet accompanies unnecessary tail energy waste. Under the objective of transmitting packets when the best channel is provided as well as a number of packets are accumulated, we propose a new mobile collaboration framework “CarrierMix” that aggregates smart devices across multiple heterogeneous cellular carriers. Compared to the standalone operation, even without a buffering delay, CarrierMix allows better channel and reduces more tail energy in a statistical point of view. To maximize the energy benefit while maintaining the fairness among the nodes in collaboration, we further develop a dynamic programming framework providing the optimal algorithm of CarrierMix and its approximated heuristic. Trace-driven simulations on our experimental HSPA/EVDO/LTE network traces show that CarrierMix of five devices achieves up to 42 percent of energy reduction.
Autors: Joohyun Lee;Kyunghan Lee;Yeongjin Kim;Song Chong;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 16 - 29
Publisher: IEEE
 
» Cartoon and Texture Decomposition-Based Color Transfer for Fabric Images
Abstract:
A color design process for fabric images can resort to a solution of a color transfer problem based on given color themes. Usually, the color transfer process contains an image segmentation phase and an image construction phase. In this paper, a novel color transfer method for fabric images is proposed. Compared with classical color transfer methods, the new method has the following three main innovations. First, the new method, in its image segmentation phase, follows an assumption that a fabric image can be decomposed into cartoon and texture components, which means the new color transfer method, in its image segmentation, phase incorporates an image decomposition process. The advantage of the innovation is that the cartoon component is more suitable than the original image to be used to partition the fabric image. Second, the new color transfer method can generate more vivid color transfer results since the above texture component is used to describe yarn texture details in the image construction phase. Third, the total generalized variation (TGV) regularizer is used to further improve the performance of image decomposition. Here, the TGV regularizer is good at estimating the weak lightness variation of the cartoon component with the CIELab color scheme. In addition, by using the augmented Lagrange multiplier method, we derive an efficient algorithm to search for the solutions to the proposed color transfer problem. Numerical results demonstrate that the proposed color transfer method can generate better results for fabric images.
Autors: Yu Han;Chen Xu;George Baciu;Min Li;Md. Robiul Islam;
Appeared in: IEEE Transactions on Multimedia
Publication date: Jan 2017, volume: 19, issue:1, pages: 80 - 92
Publisher: IEEE
 
» Cascade-Free Model Predictive Control for Single-Phase Grid-Connected Power Converters
Abstract:
In a conventional finite control set model predictive control (FCS-MPC) formulation, active and reactive power control loops rely on the predictive controller, whereas the dc-bus voltage is usually governed by a PI-based control loop. This originates from fact that the dynamic equations for describing the predictions of these variables are heavily coupled. In this paper, a cascade-free FCS-MPC for single-phase grid-connected power converters is presented. The proposed control algorithm is formulated in terms of established dynamic references design, which was originally proposed to directly govern active and reactive power, and dc-voltage in three-phase power converters. In this paper, the dynamic reference design concept is extended to control single-phase grid-connected power converters. The proposed control algorithm does not use instantaneous ac-power calculations; instead, it directly formulates the optimal control problem on the grid-current in the original stationary reference frame. The experimental results obtained with a single-phase grid-connected neutral point clamped (NPC) converter confirm a successful design, where system constraints, e.g., maximum power and weighted switching frequency, are easily taken into account.
Autors: Pablo Acuna;Ricardo P. Aguilera;Amer M. Y. M. Ghias;Marco Rivera;Carlos R. Baier;Vassilios G. Agelidis;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 285 - 294
Publisher: IEEE
 
» Changes in API RP500-2012: Combustible Liquids and Vapors
Abstract:
National Fire Protection Association 70 (NFPA 70) defines hazardous (classified) locations. API RP500-2012 establishes examples for the degree and extent for hazardous area classification boundaries around equipment and areas commonly found in petroleum facilities. The role of combustible liquids and combustible liquid-produced vapors is examined in RP500-2012, along with the comparison of their physical properties. Changes involving combustible liquids and liquid-produced vapors are examined in detail between the second and third editions of American Petroleum Institute Recommended Practice 500 (API RP500). Changes and additions to examples for hazardous (classified) location boundaries of combustible liquids and combustible liquid-produced vapors are examined. The effects of heating combustible liquids to temperatures at or greater than their flash points will require that they be classified the same as flammable liquids. This is examined in detail. Any interpretations of API RP500 are the opinions of individual presenters. Only API staff may issue API-authorized interpretations.
Autors: Robert J. Alonzo;Michael J. Russo;Kate Stavinoha;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 684 - 692
Publisher: IEEE
 
» Changes to the Editorial Board
Abstract:
Prof. Arokia Nathan, having served as Editor for IEEE Electron Device Letters since 2008, has completed his tenure. On behalf of IEEE Electron Device Letters staff and readers, I would like to thank him for his excellent contributions and dedicated service to the journal over the past nine years.
Autors: Tsu-Jae King Liu;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2017, volume: 38, issue:1, pages: 4 - 4
Publisher: IEEE
 
» Channel Allocation for Adaptive Video Streaming in Vehicular Networks
Abstract:
Video services in vehicular networks play an important role in future intelligent transportation systems and vehicular infotainment systems. Yet, at the presence of other services with high priorities, the remaining radio resources for video services are highly dynamic. To support video service of multiple vehicles in vehicular networks, we propose a joint channel allocation and adaptive video streaming algorithm that makes the vehicles compete for channel access opportunities and to request video data with a proper visual quality according to their utilities. A vehicle's request is determined by taking several key factors into consideration, including the location and the velocity of the vehicle, the activity of the high-priority services, the intensity of the competition among multiple vehicles, and the smoothness requirement of visual quality. Simulation results show that the proposed algorithm is superior to the existing algorithms in both interruption ratio and visual quality.
Autors: Long Sun;Hangguan Shan;Aiping Huang;Lin Cai;Hongli He;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 734 - 747
Publisher: IEEE
 
» Channel Estimation and Self-Interference Cancelation in Full-Duplex Communication Systems
Abstract:
This paper presents a two-stage self-interference (SI) cancelation for full-duplex multi-input–multi-output (MIMO) communications systems. By exploiting the SI channel sparsity, a compressed-sensing-based SI channel estimation technique is developed and used in the first SI-cancelation radio-frequency (RF) stage to reduce the SI power prior to the receiver low-noise amplifier (LNA) and the analog-to-digital converter (ADC) to avoid overloading. Subsequently, a subspace-based algorithm is proposed to jointly estimate the coefficients of both the residual SI and intended channels and transceiver impairments for the second SI-cancelation baseband stage to further reduce the residual SI. Unlike other previous works, the intended signal is taken into consideration during the estimation process to reduce the overhead. It is demonstrated that the SI channel coefficients can be perfectly estimated with no knowledge of the intended signal, and only a few training symbols are needed for ambiguity removal in intended-channel estimation. Simulation results show that the proposed algorithms outperform the least square (LS) algorithms and offer the remarkable signal-to-residual-SI-and-noise ratio (SINR) approaching the signal-to-noise ratio (SNR).
Autors: Ahmed Masmoudi;Tho Le-Ngoc;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 321 - 334
Publisher: IEEE
 
» Characterization of AlGaN/GaN HEMTs Using Gate Resistance Thermometry
Abstract:
In this paper, gate resistance thermometry (GRT) was used to determine the channel temperature of AlGaN/GaN high electron-mobility transistors. Raman thermometry has been used to verify GRT by comparing the channel temperatures measured by both techniques under various bias conditions. To further validate this technique, a thermal finite-element model has been developed to model the heat dissipation throughout the devices. Comparisons show that the GRT method averages the temperature over the gate width, yielding a slightly lower peak temperature than Raman thermography. Overall, this method provides a fast and simple technique to determine the average temperature under both steady-state and pulsed bias conditions.
Autors: Georges Pavlidis;Spyridon Pavlidis;Eric R. Heller;Elizabeth A. Moore;Ramakrishna Vetury;Samuel Graham;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 78 - 83
Publisher: IEEE
 
» Characterization of Contrast Agent Microbubbles for Ultrasound Imaging and Therapy Research
Abstract:
The high efficiency with which gas microbubbles can scatter ultrasound compared with the surrounding blood pool or tissues has led to their widespread employment as contrast agents in ultrasound imaging. In recent years, their applications have been extended to include super-resolution imaging and the stimulation of localized bio-effects for therapy. The growing exploitation of contrast agents in ultrasound and in particular these recent developments have amplified the need to characterize and fully understand microbubble behavior. The aim in doing so is to more fully exploit their utility for both diagnostic imaging and potential future therapeutic applications. This paper presents the key characteristics of microbubbles that determine their efficacy in diagnostic and therapeutic applications and the corresponding techniques for their measurement. In each case, we have presented information regarding the methods available and their respective strengths and limitations, with the aim of presenting information relevant to the selection of appropriate characterization methods. First, we examine methods for determining the physical properties of microbubble suspensions and then techniques for acoustic characterization of both suspensions and single microbubbles. The next section covers characterization of microbubbles as therapeutic agents, including as drug carriers for which detailed understanding of their surface characteristics and drug loading capacity is required. Finally, we discuss the attempts that have been made to allow comparison across the methods employed by various groups to characterize and describe their microbubble suspensions and promote wider discussion and comparison of microbubble behavior.
Autors: Helen Mulvana;Richard J. Browning;Ying Luan;Nico de Jong;Meng-Xing Tang;Robert J. Eckersley;Eleanor Stride;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Jan 2017, volume: 64, issue:1, pages: 232 - 251
Publisher: IEEE
 
» Characterization of LTCC-Based Ferrite Tape in ${X}$ -band and Its Application to Electrically Tunable Phase Shifter and Notch Filter
Abstract:
In this paper, low temperature cofired ceramic compatible ferrite tape (ESL 40011) is characterized in -band to study the properties of the tape in the demagnetized state. Data obtained are used to design an electrically tunable ferrite phase shifter and a tunable notch filter. These components are made electrically tunable by winding the bias coils around the ferrite substrate. They operate in the partially magnetized state at the magnetic fields <100 Oe. This biasing mechanism eliminates the use of external biasing magnet for tuning. The phase shifter occupies a total volume of ~2 cm including the bias circuitry and the test fixture. For a biased current of 700 mA, the measured differential phase shift of 215° having a figure of merit of 48°/dB is achieved at 10.6 GHz. Tunable reflection-type notch filter is designed using the same method of biasing. Center frequency of the notch is observed at 12.35 GHz. A tunability of 3.5% is achieved by varying the bias current from 50 to 450 mA. Simulation of the structures in a 3-D electromagnetic simulator shows good agreement with the measured results. High power measurements carried out up to a 2 W of input power show good stability in the performance of these components.
Autors: Srujana Kagita;Ananjan Basu;Shiban K. Koul;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 8
Publisher: IEEE
 
» Charge Trap Transistor (CTT): An Embedded Fully Logic-Compatible Multiple-Time Programmable Non-Volatile Memory Element for High- $k$ -Metal-Gate CMOS Technologies
Abstract:
The availability of on-chip non-volatile memory for advanced high--metal-gate CMOS technology nodes has been limited due to integration and scaling challenges as well as operational voltage incompatibilities, while its need continues to grow rapidly in modern high-performance systems. By exploiting intrinsic device self-heating enhanced charge trapping in as fabricated high--metal-gate logic devices, we introduce a unique multiple-time programmable embedded non-volatile memory element, called the ‘charge trap transistor’ (CTT), for high--metal-gate CMOS technologies. Functionality and feasibility of using CTT memory devices have been demonstrated on 22 nm planar and 14 nm FinFET technology platforms, including fully functional product prototype memory arrays. These transistor memory devices offer high density (/bit for 22 nm and /bit for 14 nm technology), logic voltage compatible and low peak power operation (~4mW), and excellent retention for a fully integrated and scalable embedded non-volatile memory without added process complexity or masks.
Autors: Faraz Khan;Eduard Cartier;Jason C. S. Woo;Subramanian S. Iyer;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2017, volume: 38, issue:1, pages: 44 - 47
Publisher: IEEE
 
» Charging Distributed Sensor Nodes Exploiting Clustering and Energy Trading
Abstract:
One of the main issues on wireless sensor networks is the sustainability of network operation. Sensor nodes typically acquire their energy from batteries. However, they are often deployed in hard-to-reach places, so replacing their batteries incurs substantial increase in operational cost. Therefore, energy harvesting by sensor nodes can be more cost-efficient for sustainable network operation. The harvested energy should be transmitted from a single or multiple chargers. This paper deals with a charging scheme for distributed sensors nodes. The charging scheme consists of two stages: charging by a mobile charger and charging undercharged sensor nodes by overcharged ones. The second stage is considered energy trading between seller nodes and buyer nodes. For charging in the first stage, all the sensor nodes are classified into clusters. To this end, the concept of inclusion circle is devised. By the clustering based on the inclusion circle, a sensor node, which is located around the center of grouped sensor nodes is highly likely selected as a cluster head. Charging path of the mobile charger in the first stage is determined according to the locations of cluster heads. The energy trading in the second stage is to achieve energy balancing of the sensor nodes. When the proposed two-stage charging is finished, every sensor node is charged over the target level. The proposed scheme is compared with the existing charging schemes. As a result, the total amount of charging energy and the total charging time can be significantly reduced.
Autors: Celso Moraes;Dongsoo Har;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2017, volume: 17, issue:2, pages: 546 - 555
Publisher: IEEE
 
» Charging Time Control of Wireless Power Transfer Systems Without Using Mutual Coupling Information and Wireless Communication System
Abstract:
A charging time control method for wireless power transfer systems with a secondary-side hysteresis output power control is presented. It is a primary-side control method that adopts the combined use of three concepts, namely 1) an intermediate capacitor in the receiver circuit as a power flow indicator, 2) hysteresis switching actions of a shunt decoupling power switch in the receiver circuit to regulate the dc voltage of such intermediate capacitor, and 3) the turn-on and turn-off times of the decoupling switch detected on the primary side for closed-loop control. This method has the advantage of eliminating the need for 1) precise information of the mutual inductance between the transmitter and the receiver coils and 2) wireless communication system for feedback purpose. Practical results obtained from a hardware prototype are included. They confirm the proposed operating principles and indicate that the method can automatically lead to optimal energy efficiency operation.
Autors: Wenxing Zhong;S. Y. Ron Hui;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 228 - 235
Publisher: IEEE
 
» CIACP: A Correlation- and Iteration- Aware Cache Partitioning Mechanism to Improve Performance of Multiple Coarse-Grained Reconfigurable Arrays
Abstract:
Multiple coarse-grained reconfigurable arrays (CGRA), which are organized in parallel or pipeline to complete applications, have become a productive solution to balance the performance with the flexibility. One of the keys to obtain high performance from multiple CGRAs is to manage the shared on-chip cache efficiently to reduce off-chip memory bandwidth requirements. Cache partitioning has been viewed as a promising technique to enhance the efficiency of a shared cache. However, the majority of prior partitioning techniques were developed for multi-core platform and aimed at multi-programmed workloads. They cannot directly address the adverse impacts of data correlation and computation imbalance among competing CGRAs in multi-CGRA platform. This paper proposes a correlation- and iteration- aware cache partitioning (CIACP) mechanism for shared cache partitioning in multiple CGRAs systems. This mechanism employs correlation monitors (CMONs) to trace the amount of overlapping data among parallel CGRAs, and iteration monitors (IMONs) to track the computation load of each CGRA. Using the information collected by CMONs and IMONs, the CIACP mechanism can eliminate redundant cache utilization of the overlapping data and can also shorten the total execution time of pipelined CGRAs. Experimental results showed that CIACP outperformed state-of-the-art utility-based cache partitioning techniques by up to 16 percent in performance.
Autors: Chen Yang;Leibo Liu;Kai Luo;Shouyi Yin;Shaojun Wei;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jan 2017, volume: 28, issue:1, pages: 29 - 43
Publisher: IEEE
 
» Classification of Outdoor 3D Lidar Data Based on Unsupervised Gaussian Mixture Models
Abstract:
Three-dimensional point clouds acquired with lidars are an important source of data for the classification of outdoor environments by autonomous terrestrial robots. We propose a two-layer classification model. The first layer consists of a Gaussian mixture model. This model is determined in a training step in an unsupervised manner and classified into a large set of classes. The second layer consists of a grouping of these classes. This grouping is determined by an expert during the training step and leads to a smaller set of classes that are interpretable in a considered target task. Because the first layer relies on unsupervised learning, manual labeling of data is not required. Supervision is necessary only for the second layer and in this case is assisted by the classes provided by the first layer. The evaluation is done for two data sets acquired with different lidars and possessing different characteristics. It is done quantitatively using one of the data sets and qualitatively using another. The system design follows a standard learning procedure with training, validation, and test steps. The operation follows a standard classification pipeline. The system is simple with no requirement of preprocessing or postprocessing stages.
Autors: Artur Maligo;Simon Lacroix;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2017, volume: 14, issue:1, pages: 5 - 16
Publisher: IEEE
 
» ClickSmart: A Context-Aware Viewpoint Recommendation System for Mobile Photography
Abstract:
In this paper, we propose ClickSmart, a viewpoint recommendation system that can assist a user in capturing high-quality photographs at well-known tourist locations. ClickSmart can provide real-time viewpoint recommendation based on the preview on the user’s camera, current time, and user’s geolocation. It makes use of publicly available geotagged images along with the associated metadata for learning a recommendation model. We define view-cells, macroblocks in geospace, and propose the concepts of popularity, quality, and uniqueness of view-cells from the viewpoint perspective. Viewpoint recommendation is generated at the granularity of a view-cell and is based on its popularity, quality, and uniqueness, which are estimated using social media cues associated with images. We further observe that contextual information such as time and weather conditions play an important role in photography, and therefore augment the recommendation system with the associated context. ClickSmart also takes into account the presence of people in the view for making the recommendation. It can provide two kinds of recommendations, quality based and uniqueness based. Although both were found effective in the experimental evaluation, our user study showed that uniqueness-based recommendation was preferred more by skilled photographers compared with amateurs.
Autors: Yogesh Singh Rawat;Mohan S. Kankanhalli;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jan 2017, volume: 27, issue:1, pages: 149 - 158
Publisher: IEEE
 
» Closed-Form Expressions for the Radiation Properties of Nanoloops in the Terahertz, Infrared and Optical Regimes
Abstract:
Since the pioneering work of Heinrich Hertz, perfect-electric conductor (PEC) loop antennas for RF applications have been studied extensively. Meanwhile, nanoloops are promising in the optical regime for their applications in a wide range of emerging technologies. Unfortunately, analytical expressions for the radiation properties of conducting loops have not been extended to the optical regime. This paper presents closed-form expressions for the electric fields, total radiated power, directivity, and gain for thin-wire nanoloops operating in the terahertz, infrared and optical regimes. This is accomplished by extending the formulation for PEC loops to include the effects of dispersion and loss. The expressions derived for a gold nanoloop are implemented and the results agree well with full-wave computational simulations, but with a speed increase of more than . This allows the scientist or engineer to quickly prototype designs and gain a deeper understanding of the underlying physics. Moreover, through rapid numerical experimentation, these closed-form expressions made possible the discovery that broadband superdirectivity occurs naturally for nanoloops of a specific size and material composition. This is an unexpected and potentially transformative result that does not occur for PEC loops. Additionally, the Appendices give useful guidelines on how to efficiently compute the required integrals.
Autors: Bing Qian Lu;Jogender Nagar;Taiwei Yue;Mario F. Pantoja;Douglas H. Werner;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2017, volume: 65, issue:1, pages: 121 - 133
Publisher: IEEE
 
» Closed-Form Jones Matrix of Dual-Polarized Inverted-Vee Dipole Antennas Over Lossy Ground
Abstract:
This paper presents a closed-form expression for the Jones matrix of a dual-polarized inverted-vee dipole antenna based on the Lorentz reciprocity theorem and the basic rules of electromagnetic refraction. The expression is used to determine the intrinsic cross-polarization ratio (IXR) as a function of droop angle, position of the source in the sky, antenna height, frequency, and reflection coefficient of the underlying ground. The expression is verified using full-wave simulations with a method-of-moments solver, showing very good agreement. It explains the increase in the IXR when the antenna is placed over a perfect electric ground plane. This result is used to explain the polarization properties of the Square Kilometre Array Log-periodic Antenna. Through the LOw-Frequency ARray Low-Band Antenna (LOFAR-LBA), the importance of the size of the ground plane is explained. Finally, design consideration for high polarization purity antennas is discussed.
Autors: Rene A. C. Baelemans;Adrian T. Sutinjo;Peter J. Hall;A. Bart Smolders;Michel J. Arts;Eloy de Lera Acedo;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2017, volume: 65, issue:1, pages: 26 - 35
Publisher: IEEE
 
» Closed-Form Orthogonal Ramanujan Integer Basis
Abstract:
In this letter, a closed-form orthogonal Ramanujan integer basis is proposed and obtained by performing Gram–Schmidt process from the Ramanujan sum and its circular shift. It has a surprisingly simple and sparse form, which is better than the original complete Ramanujan basis. The relationship between the original basis and proposed basis is also clearly illustrated. Therefore, the original basis can be replaced easily.
Autors: Soo-Chang Pei;Kuo-Wei Chang;
Appeared in: IEEE Signal Processing Letters
Publication date: Jan 2017, volume: 24, issue:1, pages: 1 - 1
Publisher: IEEE
 
» Cloud Attenuation Statistics Prediction From Ka-Band to Optical Frequencies: Integrated Liquid Water Content Field Synthesizer
Abstract:
The impact of cloud impairments on satellite links is increasing with the employment of higher frequency bands. In this paper, a model for predicting cloud attenuation statistics for satellite communication systems operating from -band to optical range is presented. The cloud attenuation must be accurately quantified for the reliable design of satellite communication systems. A stochastic dynamic model for the generation of integrated liquid water content (ILWC) fields is proposed. The model is based on the stochastic differential equations and incorporates the spatial and temporal behavior of ILWC. Classifying the cloud types based on the cloud vertical extent and using the microphysical properties of clouds, the well-known Mie scattering theory and the global statistics for ILWC by International Telecommunications Union–Radio (ITU-R), a unified space-time model for the prediction of induced attenuation due to clouds for frequencies above -band up to optical range is presented. The proposed model is tested in terms of first order statistics, compared first with ITU-R P.840-6 model and then with data obtained in the literature, showing encouraging results. Moreover, the probability of cloud occurrence for optical satellite single and site diversity system is calculated. Finally, the limitations and the applicability of the proposed model are discussed.
Autors: Nikolaos K. Lyras;Charilaos I. Kourogiorgas;Athanasios D. Panagopoulos;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2017, volume: 65, issue:1, pages: 319 - 328
Publisher: IEEE
 
» Clustering-Based Spectrum Sharing Strategy for Cognitive Radio Networks
Abstract:
In this paper, we propose a clustering-based resource allocation (RA) scheme for the multiuser orthogonal frequency division multiplexing (OFDM)-based cognitive radio network, where we aim to maximize the sum capacity of the secondary users (SUs) subject to practical constraints in wireless environment. Our general RA optimization task leads to a challenging mixed integer programming problem that is computationally intractable. We first introduce a simple and efficient clustering method to divide all the SUs into multiple groups based on their mutual interference degrees, where the SUs in different groups can share the same OFDM subchannels to improve spectrum utilization efficiency, while the SUs with heavy mutual interference cluster together in the same group and employ different subchannels to alleviate their mutual interference. Then we develop efficient radio RA algorithms to maximize the sum rate of the SUs in each cluster. A user-oriented subchannel assignment method is presented to remove the awkward integer constraints of the formulated RA problem, followed by a fast power distribution algorithm that can work out optimal solutions with an approximate linear complexity. Simulation results indicate that our proposed RA scheme can improve the throughput of the SUs significantly as compared with other methods. Moreover, our proposed RA algorithms converge stably and quickly.
Autors: Jingyi Dai;Shaowei Wang;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jan 2017, volume: 35, issue:1, pages: 228 - 237
Publisher: IEEE
 
» Clutter Rank Estimation for Reduce-Dimension Space-Time Adaptive Processing MIMO Radar
Abstract:
Estimation of clutter rank in the reduce-dimension (RD) domain has great importance for RD space-time adaptive processing (STAP) algorithms. In this letter, clutter rank estimation rules of RD STAP algorithms for multiple input multiple output (MIMO) radar with different parameters are developed. The accuracy of the proposed rules is verified and the way to design RD MIMO STAP processor under the guidance of the proposed rules is presented.
Autors: Weike Feng;Yongshun Zhang;Xingyu He;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2017, volume: 17, issue:2, pages: 238 - 239
Publisher: IEEE
 
» Co-Primary Spectrum Sharing for Inter-Operator Device-to-Device Communication
Abstract:
The business potential of device-to-device (D2D) communication including public safety and vehicular communications will be realized only if direct communication between devices subscribed to different mobile operators (OPs) is supported. One possible way to implement inter-operator D2D communication may use the licensed spectrum of the OPs, i.e., OPs agree to share spectrum in a co-primary manner, and inter-operator D2D communication is allocated over spectral resources contributed from both parties. In this paper, we consider a spectrum sharing scenario, where a number of OPs construct a spectrum pool dedicated to support inter-operator D2D communication. OPs negotiate in the form of a non-cooperative game about how much spectrum each OP contributes to the spectrum pool. OPs submit proposals to each other in parallel until a consensus is reached. When every OP has a concave utility function on the box-constrained region, we identify the conditions guaranteeing the existence of a unique equilibrium point. We show that the iterative algorithm based on the OP’s best response might not converge to the equilibrium point due to myopically overreacting to the response of the other OPs, while the Jacobi-play strategy update algorithm can converge with an appropriate selection of update parameter. Using the Jacobi-play update algorithm, we illustrate that asymmetric OPs contribute an unequal amount of resources to the spectrum pool; however, all participating OPs may experience significant performance gains compared with the scheme without spectrum sharing.
Autors: Byungjin Cho;Konstantinos Koufos;Riku Jäntti;Seong-Lyun Kim;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jan 2017, volume: 35, issue:1, pages: 91 - 105
Publisher: IEEE
 
» CO2/CO concentration ratio: A complementary method for determining the degree of polymerization of power transformer paper insulation
Abstract:
Since power transformers are valuable components of power networks, reliable determination of the remaining lifetime of a transformer is very important for power utilities. Power transformers consist of oil, a core, wire, and paper (cellulose), and their performance and remaining useful lifetime depend on the state of the oil-impregnated paper. Changing the oil over the lifetime of a transformer is possible, but it is not possible to change the insulation paper. Thus, the end of the paper lifetime will also be the end of the transformer lifetime (typically more than 40 years). The health condition of an in-service power transformer can be assessed by chemical and electrical tests of the oil and the paper [1].
Autors: Ashkan Teymouri;Behrooz Vahidi;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: Jan 2017, volume: 33, issue:1, pages: 24 - 30
Publisher: IEEE
 
» Codebook Design for Millimeter-Wave Channel Estimation With Hybrid Precoding Structure
Abstract:
In this paper, we study hierarchical codebook design for channel estimation in millimeter-wave (mmWave) communications with a hybrid precoding structure. Due to the limited saturation power of the mmWave power amplifier, we consider the per-antenna power constraint (PAPC). We first propose a metric, termed generalized detection probability (GDP), to evaluate the quality of an arbitrary codeword. This metric not only enables an optimization approach for mmWave codebook design, but also can be used to compare the performance of two different codewords/codebooks. To the best of our knowledge, GDP is the first such metric, particularly for mmWave codebook design. We then propose a heuristic approach to design a hierarchical codebook exploiting beam widening with the multi-RF-chain sub-array (BMW-MS) technique. To obtain crucial parameters of BMW-MS, we provide two solutions, namely, a low-complexity search (LCS) solution to optimize the GDP metric and a closed-form (CF) solution to pursue a flat beam pattern. Performance comparisons show that BMW-MS/LCS and BMW-MS/CF achieve very close performances, and they outperform the existing alternatives under the PAPC.
Autors: Zhenyu Xiao;Pengfei Xia;Xiang-Gen Xia;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 141 - 153
Publisher: IEEE
 
» Coil Excited Pseudo Direct Drive Electrical Machines
Abstract:
A pseudo direct drive (PDD) equipped with a coil-excited high-speed (HS) rotor is presented. An analytical model which predicts the flux density in the air spaces and the permanent magnets (PMs) of the PDD is presented, and it is shown that good agreement exists between the analytical and finite-element predictions. Furthermore, the model is employed to investigate the effects of the key design parameters on the performance of a coil-excited PDD for a 10-MW wind turbine application, and an optimized design is proposed. It is shown that shear stress in excess of 100 kPa can be achieved, and that compared with a PM-excited PDD, a reduction in PM mass can be realized. It is also shown that the efficiency over the operating range of the wind turbine can be maximized by adopting an appropriate control strategy of the HS rotor excitation currents.
Autors: A. Penzkofer;G. Cooke;M. Odavic;K. Atallah;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 11
Publisher: IEEE
 
» Collaborative Smartphone Sensing Using Overlapping Coalition Formation Games
Abstract:
With the rapid growth of sensor technology, smartphone sensing has become an effective approach to improve the quality of smartphone applications. However, due to time-varying wireless channels and lack of incentives for the users to participate, the quality and quantity of the data uploaded by the smartphone users are not always satisfying. In this paper, we consider a smartphone sensing system in which a platform publicizes multiple tasks, and the smartphone users choose a set of tasks to participate in. In the traditional non-cooperative approach with incentives, each smartphone user gets rewards from the platform as an independent individual and the limit of the wireless channel resources is often omitted. To tackle this problem, we introduce a novel cooperative approach with an overlapping coalition formation game (OCF-game) model, in which the smartphone users can cooperate with each other to form the overlapping coalitions for different sensing tasks. We also utilize a centralized case to describe the upper bound of the system sensing performance. Simulation results show that the cooperative approach achieves a better performance than the non-cooperative one in various situations.
Autors: Boya Di;Tianyu Wang;Lingyang Song;Zhu Han;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 30 - 43
Publisher: IEEE
 
» Collective First-Person Vision for Automatic Gaze Analysis in Multiparty Conversations
Abstract:
This paper targets small- to medium-sized-group face-to-face conversations where each person wears a dual-view camera, consisting of inward- and outward-looking cameras, and presents an almost fully automatic but accurate ofline gaze analysis framework that does not require users to perform any calibration steps. Our collective first-person vision framework, where captured audio–visual signals are gathered and processed in a centralized system, jointly undertakes the fundamental functions required for group gaze analysis, including speaker detection, face tracking, and gaze tracking. Of particular note is our self-calibration of gaze trackers by exploiting a general conversation rule, namely that listeners are likely to look at the speaker. From the rough conversational prior knowledge, our system visualizes fine-grained participants’ gaze behavior as a gazee-centered heat map, which quantitatively reveals what parts of the gazee's body the participant looked at and for how long while the gazer was speaking or listening. An experiment using conversations amounting to a total of 140 min, each lasting an average of 8.7 min and engaged in by 37 participants in groups of three to six, achieves a mean absolute error of 2.8 in gaze tracking. A statistical test reveals neither a group size effect nor a conversation type effect. Our method achieves F-scores of over 0.89 and 0.87 in gazee and eye contact recognition, respectively, in comparison with human annotation.
Autors: Shiro Kumano;Kazuhiro Otsuka;Ryo Ishii;Junji Yamato;
Appeared in: IEEE Transactions on Multimedia
Publication date: Jan 2017, volume: 19, issue:1, pages: 107 - 122
Publisher: IEEE
 
» Color-Based Segmentation of Sky/Cloud Images From Ground-Based Cameras
Abstract:
Sky/cloud images captured by ground-based cameras (a.k.a. whole sky imagers) are increasingly used nowadays because of their applications in a number of fields, including climate modeling, weather prediction, renewable energy generation, and satellite communications. Due to the wide variety of cloud types and lighting conditions in such images, accurate and robust segmentation of clouds is challenging. In this paper, we present a supervised segmentation framework for ground-based sky/cloud images based on a systematic analysis of different color spaces and components, using partial least-squares regression. Unlike other state-of-the-art methods, our proposed approach is entirely learning based and does not require any manually defined parameters. In addition, we release the Singapore whole Sky imaging segmentation database, a large database of annotated sky/cloud images, to the research community.
Autors: Soumyabrata Dev;Yee Hui Lee;Stefan Winkler;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 231 - 242
Publisher: IEEE
 
» Combining High Hole Concentration in p-GaN and High Mobility in u-GaN for High p-Type Conductivity in a p-GaN/u-GaN Alternating-Layer Nanostructure
Abstract:
p-GaN/u-GaN alternating-layer nanostructures are grown with molecular beam epitaxy to show a low p-type resistivity level of -cm. The obtained low resistivity is due to the high hole mobility in the u-GaN layers, which serve as effective transport channels of holes diffused from the neighboring p-GaN layers. The Mg doping in a thin p-GaN layer can lead to a high Mg-doping concentration for supplying holes to the neighboring u-GaN layers. Simulations based on a 1-D drift diffusion charge control model and the Brooks–Herring theory of ionized impurity scattering are undertaken to first obtain the depth-dependent distributions of hole concentration, mobility, and, hence, resistivity. Then, weighted averaging processes are used for evaluating the effective hole concentration, mobility, and resistivity of a p-GaN/u-GaN alternating-layer nanostructure to give consistent results with the measured data.
Autors: Hao-Tsung Chen;Chia-Ying Su;Charng-Gan Tu;Yu-Feng Yao;Chun-Han Lin;Yuh-Renn Wu;Yean-Woei Kiang;Chih-Chung C. C. Yang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 115 - 120
Publisher: IEEE
 
» Commencement of operation of the world's largest storage battery facility [News from Japan]
Abstract:
Natural electric power resources such as solar cells and wind power have been more widely used in recent years. However, the output from such power resources very often fluctuates, depending on various natural conditions. Consequently, we need technologies that can store electric energy in order to realize stable operation of power grids incorporating natural power resources. Pumped hydropower is one such technology, but it has become difficult to find suitable places to build new pumped hydropower stations.
Autors: Y. Ohki;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: Jan 2017, volume: 33, issue:1, pages: 59 - 61
Publisher: IEEE
 
» Comments on “Compact Dual-Band Branch-Line Coupler With Dual Transmission Lines”
Abstract:
The synthesis and design method for the dual-band, dual transmission line branch-line coupler in [1] involves equivalent circuit transformations that are single-banded in nature and not suitable for the dual-band operations. The proposed equivalent dual transmission line transform has been applied only in the middle of the dual-band operation frequencies and its validity has not been confirmed at the two band frequencies. As the result, the proposed circuit equivalence can be quite poor and the coupler design in [1] based on it can be quite erroneous at the dual-band operation frequencies.
Autors: Myun-Joo Park;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2017, volume: 27, issue:1, pages: 103 - 104
Publisher: IEEE
 

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