Electrical and Electronics Engineering publications abstract of: 07-2017 sorted by title, page: 10

» Message From the Incoming Editor-in-Chief
Abstract:
Autors: N. Kato;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 5517 - 5517
Publisher: IEEE
 
» Metameric Indoor Localization Schemes Using Visible Lights
Abstract:
In indoor environments, visible light communications paradigm is emerging as a viable promising solution complementary to well-known radio frequency technology. At the same time, the information about user's location is useful for accessing the medium via space-division multiplexing, handling over or providing access to location-based contents. In this paper, we present two localization mechanisms based on the wavelength domain by assuming that each anchor point uses a spectrally dedicated signature for the user to readily identify it. The first approach, i.e., wavelength-based localization, assumes a simultaneous transmission of three different pulse streams emitted by the red-green-blue (RGB) light emitting diodes (LEDs). The second method, i.e., colorbased localization, considers the subsequent transmission of RGB pulses. Localization is then computed through traditional received signal strength and time difference of arrival approaches. Moreover, we resort to the properties of metamerism so that the red, green, and blue components used by LEDs provide the white light sensation to the human eye. The performances of the two proposed schemes are close to theoretical bounds. Even in the worst cases, the estimation error variance is in the order of 10-4 m2. Finally, the signaling request for estimating user position is less than others in the literature and is independent from the number of anchor points.
Autors: Stefano Pergoloni;Zeinab Mohamadi;Anna Maria Vegni;Zabih Ghassemlooy;Mauro Biagi;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 2933 - 2942
Publisher: IEEE
 
» Method to Further Improve Sensitivity for High-Order Vibration Mode Mass Sensors With Stepped Cantilevers
Abstract:
Using high-order vibration mode has been regarded as an effective way to improve the sensitivity of piezoelectric resonant cantilever mass sensors. To further improve the high-order mode sensitivity without reducing the overall dimension, a new shape design method was proposed to improve the sensitivity at the desired high-order vibration mode by optimizing the multi-stepped thickness along the cantilever axis. With the proposed method, a new fourth-order mode mass sensor is proposed incorporating a three-stepped piezoelectric-elastic composite cantilever. The effect of structural parameters on the vibration modes and also the sensitivity is analyzed. With the optimized three-stepped cantilever, the sensitivity can be at least 3.0 times that of the uniformed cantilever sensor also operated in the fourth-order vibration mode. Then, a piezoelectric mass sensor is fabricated with the step thickness ratio and step length ratio of 0.5 and 0.29. The experimental results show that the fourth-order mode sensitivity can achieve Hz/g, which is nearly 19.5 times and 3.0 times greater than those of the custom uniform cantilever sensor working in the first and fourth vibration modes. Meanwhile, the quality factor is 82.65 about 3.5 times as great as that of the rectangular uniform cantilever sensor. The nearly consistency between simulation and experiments fully validates the feasibility and effectiveness of the newly proposed sensitivity improving method.
Autors: Renjing Gao;Yu Huang;Xin Wen;Jian Zhao;Shutian Liu;
Appeared in: IEEE Sensors Journal
Publication date: Jul 2017, volume: 17, issue:14, pages: 4405 - 4411
Publisher: IEEE
 
» Microgrid Control Strategy: Derived from Stakeholder Requirements Analysis
Abstract:
The energy market is recognizing that both distributed generators and controlled loads are valuable assets when properly integrated into a utility's power and communications networks. However, the proliferation of these distributed energy resources (DERs) creates challenges for utilities when interconnected to their networks. Traditional operational models, including sensing and computational tools, will not be enough to meet future needs. Specifically, the monitoring and control layer (some call it the IT layer) will need to be transformed to adequately integrate DERs.
Autors: Alex Rojas;Tamer Rousan;
Appeared in: IEEE Power and Energy Magazine
Publication date: Jul 2017, volume: 15, issue:4, pages: 72 - 79
Publisher: IEEE
 
» Microgrid Control Systems: A Practical Framework [In My View]
Abstract:
The growing interest in microgrids has brought a great level of focus, creativity, and investment in the development and commercialization of microgrid control systems. The primary value propositions for microgrids are improving reliability and resiliency, enabling renewable generation integration at a higher penetration level than normal, enhancing efficiency, and the economic dispatch of distributed generation to reduce operation and maintenance costs and create new revenue streams (for instance, through participation in the energy or ancillary service markets). All of these efforts emphasize the need for a microgrid control system that can operate the system autonomously in a coordinated fashion to achieve predefined performance goals.A growing interest in microgrids has brought a great level of focus, creativity, and investment in the development and commercialization of microgrid control systems (more commonly called controllers). The primary value propositions for microgrids are improving reliability and resiliency, enabling renewable generation integration at a higher penetration level than normal, enhancing efficiency, and the economic dispatch of distributed generation to reduce operation and maintenance costs and create new revenue streams (for instance, through participation in the energy or ancillary service markets). All of these efforts emphasize the need for a microgrid control system that can operate the system autonomously in a coordinated fashion to achieve predefined performance goals.
Autors: Farid Katiraei;Amin Zamani;Ralph Masiello;
Appeared in: IEEE Power and Energy Magazine
Publication date: Jul 2017, volume: 15, issue:4, pages: 116 - 112
Publisher: IEEE
 
» Microgrid Controller Design, Implementation, and Deployment: A Journey from Conception to Implementation at the Philadelphia Navy Yard
Abstract:
The Philadelphia Navy Yard is a fast-evolving community microgrid, currently home to over 150 companies and four Navy activity centers occupying nearly 7.5 million ft<sup>2</sup> of buildings in which approximately 12,500 people are employed. The Navy Yard (TNY) is a national center of excellence for energy research, education, and commercialization, focused specifically on community microgrid design and development. TNY microgrid is equipped with the most cost-effective and sustainable means for meeting electric capacity and energy needs through renewable resources, energy efficiency, and distribution grid infrastructure. This article briefly describes how the community microgrid was conceived and planned to produce a great success story of microgrid implementation and the details of the design, development, and implementation of TNY's microgrid controller.
Autors: R. Uluski;J. Kumar;S.S. Mani Venkata;D. Vishwakarma;K. Schneider;Ali Mehrizi-Sani;Rudy Terry;Will Agate;
Appeared in: IEEE Power and Energy Magazine
Publication date: Jul 2017, volume: 15, issue:4, pages: 50 - 62
Publisher: IEEE
 
» Microgrid Controller Initiatives: An Overview of R&D by the U.S. Department of Energy
Abstract:
The microgrid is a concept for which the controller is the defining and enabling technology. Indeed, the microgrid may be defined as the resources-generation, storage, and loads-within a boundary that are managed by the controller.
Autors: Dan Ton;James Reilly;
Appeared in: IEEE Power and Energy Magazine
Publication date: Jul 2017, volume: 15, issue:4, pages: 24 - 31
Publisher: IEEE
 
» Microgrid Controllers : Expanding Their Role and Evaluating Their Performance
Abstract:
Microgrids have long been deployed to provide power to customers in remote areas as well as critical industrial and military loads. Today, they are also being proposed as grid-interactive solutions for energy-resilient communities. Such microgrids will spend most of the time operating while synchronized with the surrounding utility grid but will also be capable of separating during contingency periods due to storms or temporary disturbances such as local grid faults. Properly designed and grid-integrated microgrids can provide the flexibility, reliability, and resiliency needs of both the future grid and critical customers. These systems can be an integral part of future power system designs that optimize investments to achieve operational goals, improved reliability, and diversification of energy sources.
Autors: Arindam Maitra;Annabelle Pratt;Tanguy Hubert;Dean Wang;Kumaraguru Prabakar;Rachna Handa;Murali Baggu;Mark McGranaghan;
Appeared in: IEEE Power and Energy Magazine
Publication date: Jul 2017, volume: 15, issue:4, pages: 41 - 49
Publisher: IEEE
 
» Microgrid Controllers: The Brain, Heart, & Soul of Microgrid Automation [Guest Editorial]
Abstract:
The articles in this special section address the technology of microgrid controllers and examines various applications for their use. Achieving the goal of developing this technology is the design, development, and implementation of a suitable microgrid controller that fits customers’ needs and requirements and achieves key performance indexes such as perfect reliability for critical loads. It also accords the highest level of resiliency while protecting the environment; meeting customer satisfaction at a reduced cost; and providing autonomy, safety, and security to all involved in this process. Various microgrid control architectures are being pursued: centralized, decentralized, and hierarchical. Hierarchical could further be classified as primary, secondary, and tertiary control. These types of control could be dissimilar to different users.
Autors: S.S. Mani Venkata;Mohammad Shahidehpour;
Appeared in: IEEE Power and Energy Magazine
Publication date: Jul 2017, volume: 15, issue:4, pages: 16 - 22
Publisher: IEEE
 
» Microgrid Controllers: Their Important Role in the System [From the Editor]
Abstract:
Presents the introductory editorial for this issue of the publication.
Autors: Michael Henderson;
Appeared in: IEEE Power and Energy Magazine
Publication date: Jul 2017, volume: 15, issue:4, pages: 4 - 6
Publisher: IEEE
 
» Microgrid Protection
Abstract:
The proliferation of distributed energy resources is setting the stage for modern distribution systems to operate as microgrids, which can avoid power disruptions and serve as resources for fast recovery during macrogrid disturbances. Microgrids are, therefore, major assets to improve the grid resilience. However, the offered resilience is seriously undermined if microgrids are not properly protected in the event of faults within their own boundaries. Distribution protective devices cannot reliably protect microgrids due to the variable and often limited short-circuit capacities of microgrids. Moreover, the research on microgrid protection has not led to a commercially available microgrid relay to date and has little prospect of reaching that level in the near future. As a result, the existing options for reliable microgrid protection remain effectively the subtransmission and transmission system protective devices, e.g., directional overcurrent, distance, and differential relays. Although years of operation in macrogrids support these relays, their performance for microgrids is yet to be analyzed. This paper presents such analysis for different relay types by considering various fault and generation conditions in a microgrid. Time-domain simulations are used to identify the scenarios where the relays function correctly as well as the problematic conditions, on which future research should focus. This paper also presents a short review on direct current (dc) microgrids and their protection requirements.
Autors: Ali Hooshyar;Reza Iravani;
Appeared in: Proceedings of the IEEE
Publication date: Jul 2017, volume: 105, issue:7, pages: 1332 - 1353
Publisher: IEEE
 
» Mid-Infrared Octave-Spanning Supercontinuum and Frequency Comb Generation in a Suspended Germanium-Membrane Ridge Waveguide
Abstract:
Stable octave-spanning supercontinuum (SC) in the mid-infrared (MIR) region finds extensive applications in spectroscopy, metrology, biochemistry, etc. The absorption of conventional silicon- or silicon oxide-dominated nonlinear media makes SC generation in MIR region technically challenging. In this paper, we propose ultrabroadband MIR-SC generation using a suspended germanium-membrane ridge waveguide. We theoretically showed that when pump pulses centered at 4.8 μm with pulse width at 180 fs and peak power at 800 W are injected into a 4-mm-long proposed ridge waveguide, the SC generated ranges from 1.96–12 μm (about 2.6 octaves), extending deep into the “fingerprint” region. The first-order coherence is calculated to confirm the stability of the generated SC. The performance of the SC-based frequency comb is also investigated by assuming a 100-pulses pump source at a repetition rate of 100 kHz.
Autors: Jinhui Yuan;Zhe Kang;Feng Li;Xianting Zhang;Xinzhu Sang;Qiang Wu;Binbin Yan;Kuiru Wang;Xian Zhou;Kangping Zhong;Guiyao Zhou;Chongxiu Yu;Chao Lu;Hwa Yaw Tam;P. K. A. Wai;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2017, volume: 35, issue:14, pages: 2994 - 3002
Publisher: IEEE
 
» Migration of Multipactor Trajectories via Higher-Order Mode Perturbation
Abstract:
The present paper examines how multipactor impact points change when a perturbative harmonic mode is present, in addition to the fundamental mode which is primarily driving the multipactor. We propose a steerability-to-zero criterion to determine under what conditions a multipactor trajectory can be controlled through the perturbative mode. Simulated results are shown for a parallel-plate geometry, and the results are expected to be generalizable to coaxial and more complicated geometries. The results show that for the second, third, and fourth harmonics examined as perturbative modes, steerability-to-zero is possible under some circumstances, typically when the harmonic mode magnetic field is much stronger than the fundamental mode magnetic field. The results also show that to a good approximation, it is only the ratio of the magnetic fields between the perturbative and fundamental modes which determines whether or not multipactor trajectories can be controlled; this is because if two magnetic fields are present and are both scaled by the same factor, then the direction of the charged particle’s deflection due to the magnetic fields will remain the same.
Autors: Scott A. Rice;John P. Verboncoeur;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jul 2017, volume: 45, issue:7, pages: 1739 - 1745
Publisher: IEEE
 
» Millimeter Wave Beam Alignment: Large Deviations Analysis and Design Insights
Abstract:
In millimeter wave cellular communication, fast and reliable beam alignment via beam training is crucial to harvest sufficient beamforming gain for the subsequent data transmission. In this paper, we establish fundamental limits in beam-alignment performance under both the exhaustive search and the hierarchical search that adopts multi-resolution beamforming codebooks, accounting for time-domain training overhead. Specifically, we derive lower and upper bounds on the probability of misalignment for an arbitrary level in the hierarchical search, based on a single-path channel model. Using the method of large deviations, we characterize the decay rate functions of both bounds and show that the bounds coincide as the training sequence length goes large. We go on to characterize the asymptotic misalignment probability of both the hierarchical and exhaustive search, and show that the latter asymptotically outperforms the former, subject to the same training overhead and codebook resolution. We show via numerical results that this relative performance behavior holds in the non-asymptotic regime. Moreover, the exhaustive search is shown to achieve significantly higher worst case spectrum efficiency than the hierarchical search, when the pre-beamforming signal-to-noise ratio (SNR) is relatively low. This paper hence implies that the exhaustive search is more effective for users situated further from base stations, as they tend to have low SNR.
Autors: Chunshan Liu;Min Li;Stephen V. Hanly;Iain B. Collings;Philip Whiting;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jul 2017, volume: 35, issue:7, pages: 1619 - 1631
Publisher: IEEE
 
» Millimeter Wave Communications for Future Mobile Networks (Guest Editorial), Part I
Abstract:
For the potential of providing rates of multiple Giga-bps in a single channel, millimeter wave (mmWave) communications have recently attracted substantial research interest. While mmWave technology is already being used in stationary scenarios such as indoor hotspots or backhaul, it is challenging to use mmWave frequencies in mobile networks, where transmitting/receiving nodes may be moving, channels may have a complicated structure, and the coordination among multiple nodes is difficult. To fully exploit the high potential rates of mmWave in mobile networks, many significant technical challenges must be tackled. The main objective of this IEEE JSAC Special Issue on “Millimeter wave communications for future mobile networks” is to collect the most recent technical advances in mmWave for future mobile networks. The response from the community to the call has been overwhelming. We received 96 submissions with a call period short than 4 months. Many of the submissions are from the most well known research groups in the field. After a strict review process, we decided to accept 38 papers, which will be published in two issues. The papers were selected based on the technical relevance and merits. Unfortunately, due to space limitations, a number of interesting papers were not selected, despite the merits that they had. We sincerely hope those papers can find other publishing venues.
Autors: Ming Xiao;Shahid Mumtaz;Yongming Huang;Linglong Dai;Yonghui Li;Michail Matthaiou;George K. Karagiannidis;Emil Björnson;Kai Yang;I. Chih-Lin;Amitabha Ghosh;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jul 2017, volume: 35, issue:7, pages: 1425 - 1431
Publisher: IEEE
 
» MILP-Based Optimization of 2-D Block Masks for Timing-Aware Dummy Segment Removal in Self-Aligned Multiple Patterning Layouts
Abstract:
Self-aligned multiple patterning, due to its low overlay error, has emerged as the leading option for 1-D gridded back-end-of-line (BEOL) in sub-14-nm nodes. To form actual routing patterns from a uniform “sea of wires,” cut masks are needed for line-end cutting or realization of space between routing segments. The line-end cutting results in nonfunctional (i.e., dummy fill) patterns that change wire capacitance, and hence design timing and power. Therefore, to remove such dummy fill patterns, extra 2-D block masks are used. However, 2-D block masks cannot remove arbitrary dummy fill patterns, due to design rule constraints on the block mask shapes. In this paper, we address the timing-aware optimization of 2-D block mask layouts under various sets of mask rules that are derived from mask patterning technology options (e.g., 193i and 193d) for foundry 7-/5-nm (N7/N5) BEOL. Our central contribution is a mixed integer linear programming (MILP) optimization that minimizes timing impact due to dummy metal segments while satisfying block mask rules and metal density constraints. We also propose a distributed optimization flow to improve the scalability. With our optimizer, we recover up to 84% of the worst negative slack impact from dummy segments, with up to 64% dummy removal rate. We further extend our MILP to a co-optimization of cut and block masks. This paper gives new insights into fundamental limits of benefit from emerging cut and block mask technology options.
Autors: Peter Debacker;Kwangsoo Han;Andrew B. Kahng;Hyein Lee;Praveen Raghavan;Lutong Wang;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jul 2017, volume: 36, issue:7, pages: 1075 - 1088
Publisher: IEEE
 
» MIMO Switched-Capacitor DC–DC Converters Using Only Parasitic Capacitances Through Scalable Parasitic Charge Redistribution
Abstract:
This paper presents a multiple-input multiple-output (MIMO) switched-capacitor (SC) dc–dc converter that only uses the parasitic capacitance already present in fully integrated SC power converters to generate multiple dc voltages. When used in an SC converter together with the scalable parasitic charge redistribution technique, the presented MIMO converter provides additional voltage rails, which can be used to power gate drivers or control blocks without any area overhead. Moreover, because the proposed converter only makes use of elements, which are already present in fully integrated SC converters, only conductive losses are introduced. This means that, for low output powers, efficiencies arbitrarily close to 100% can be achieved. The presented type of converter is characterized using an MIMO model, which is, in turn, used to prove the efficiency of the converter compared with regular SC MIMO converters, particularly for a large number of inputs or outputs. Measurements verify the basic working principle of the presented converter, demonstrating a peak efficiency of 98.9% and output powers sufficient to power internal converter blocks.
Autors: Nicolas Butzen;Michiel S. J. Steyaert;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2017, volume: 52, issue:7, pages: 1814 - 1824
Publisher: IEEE
 
» MIMO Transmission for Single-Fed ESPAR With Quantized Loads
Abstract:
Compact parasitic arrays in the form of electronically steerable parasitic antenna radiators (ESPARs) have emerged as a new antenna structure that achieves multiple-input-multiple-output (MIMO) transmission with a single RF chain. In this paper, we study the application of precoding on practical ESPARs, where the antennas are equipped with load impedances of quantized values. We analytically study the impact of the quantization on the system performance, where it is shown that while ideal ESPARs with ideal loads can achieve a similar performance to conventional MIMO, the performance of ESPARs will be degraded when only loads with quantized values are available. We further extend the performance analysis to imperfect channel state information. In order to alleviate the performance loss, we propose to approximate the ideal current vector by optimization, where a closed-form solution is further obtained. This enables the use of ESPARs in practice with quantized loads. Simulation results validate our analysis and show that a significant performance gain can be achieved with the proposed scheme over ESPARs with quantized loads. Finally, the tradeoff between performance and power consumption is shown to be favorable for the proposed ESPAR approaches compared with conventional MIMO, as evidenced by our energy efficiency results.
Autors: Ang Li;Christos Masouros;Constantinos B. Papadias;
Appeared in: IEEE Transactions on Communications
Publication date: Jul 2017, volume: 65, issue:7, pages: 2863 - 2876
Publisher: IEEE
 
» MIMO-STBC Based Multiple Relay Cooperative Communication Over Time-Selective Rayleigh Fading Links With Imperfect Channel Estimates
Abstract:
This paper analyzes the effect of time-selective fading arising due to node mobility and imperfect channel estimates on the end-to-end performance of multiple-input multiple-output space-time block coded multiple relay cooperative communication systems. Both dual-phase and multi-phase selective decode-and-forward relaying protocols are considered for the end-to-end communication in a multiple relay cooperative system, followed by presentation of complete analyses for the same. For each protocol, closed-form expressions are derived for the per-frame average pair-wise error probability and asymptotic error floor over independent and nonidentical time-selective Rayleigh fading links. A framework is also developed for obtaining the optimal source relay power factors for each of the above protocols, which significantly improve the end-to-end reliability of the system for a given power budget. It is shown that both the multirelay systems achieve the full diversity order (DO) when all the nodes are static and perfect channel estimates are available at each receiving node. The DO of the system reduces to that of the direct source–destination link for a scenario when only the relays are mobile. Interestingly, however, in other mobile scenarios, both the systems are limited by an asymptotic error floor with increasing signal to noise ratio. Further, the impact of DO of the source–relay and relay–destination links on the optimal source–relay power allocation is also explicitly demonstrated. Simulation results yield several important insights into the end-to-end error performance for different mobility conditions and also validate the derived analytical results.
Autors: Neeraj Varshney;Aditya K. Jagannatham;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 6009 - 6025
Publisher: IEEE
 
» Mind the (Gender) Gap [President's Message]
Abstract:
Presents the President’s message for this issue of the publication.
Autors: Rabab Ward;
Appeared in: IEEE Signal Processing Magazine
Publication date: Jul 2017, volume: 34, issue:4, pages: 4 - 5
Publisher: IEEE
 
» Miniaturized Frequency Controllable Band-Stop Filter Using Coupled-Line Stub-Loaded Shorted SIR for Tri-Band Application
Abstract:
Based on the coupled-line stub-loaded shorted stepped-impedance resonator (CLSLSSIR), a compact microstrip tri-band band-stop filter (TB-BSF) with controllable frequencies, stopband attenuations (SAs), and sharp transition band roll-off skirts has been presented. The proposed CLSLSSIR exhibits multimode resonant behavior and is employed to achieve tri-stopband application by applying the virtual ground effect at the attaching position. Due to the infinite input impedance effect of CLSLSSIR, as well as the resonance of -type network combined with two loaded CLSLSSIRs and transmission line, multiple transmission poles can be yielded to obtain high selectivity of transition band. Finally, an example TB-BSF operating at 1.57, 2.4, and 3.5 GHz with respective SAs of 18, 26.5, and 33.2 dB has been designed and fabricated.
Autors: Jing Ai;Yong Hong Zhang;Kai Da Xu;Meng Kui Shen;William T. Joines;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jul 2017, volume: 27, issue:7, pages: 627 - 629
Publisher: IEEE
 
» Miniaturized Quarter-Mode Substrate Integrated Cavity Resonators for Humidity Sensing
Abstract:
This letter presents the substantial miniaturization of substrate integrated waveguide sensors using quarter-mode and ridged quarter-mode techniques, for detecting changes in relative humidity levels between 0%–80%. Miniaturizations of 73.3% and 86.2% are reported with resonant frequencies of 6 GHz and 6.9 GHz for the two techniques, respectively. Furthermore, an increase in humidity sensitivity is achieved almost four times greater than previously reported. Due to the reduced size and increased sensitivity, these two techniques open up new possibilities and applications for sensor design. To the best of the authors’ knowledge, this letter also reports the first ridged quarter-mode resonant structure, providing even greater miniaturizations and improved quality factor of quarter-mode structures in the literature.
Autors: Thomas R. Jones;Mohammad H. Zarifi;Mojgan Daneshmand;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jul 2017, volume: 27, issue:7, pages: 612 - 614
Publisher: IEEE
 
» Minimax Lower Bound and Optimal Estimation of Convex Functions in the Sup-Norm
Abstract:
Estimation of convex functions finds broad applications in science and engineering; however, the convex shape constraint complicates the asymptotic performance analysis of such estimators. This technical note is devoted to the minimax optimal estimation of univariate convex functions in a given Hölder class. Particularly, a minimax lower bound in the supremum norm (or simply sup-norm) is established by constructing a novel family of piecewise quadratic convex functions in the Hölder class. This result, along with a recent result on the minimax upper bound, gives rise to the optimal rate of convergence for the minimax sup-norm risk of convex functions with the Hölder order between one and two. The present technical note provides the first rigorous justification of the optimal minimax risk for convex estimation on the entire interval of interest in the sup-norm.
Autors: Teresa M. Lebair;Jinglai Shen;Xiao Wang;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3482 - 3487
Publisher: IEEE
 
» Minimizing Secrecy Outage Probability in Multiuser Wireless Systems With Stochastic Traffic
Abstract:
We first extend the definition of the secrecy outage probability to wireless systems with adaptive transmission rates and secrecy rates. Then, we consider a scheduling problem in the aforementioned system, jointly considering the reliability, security, and stability, where the scheduler tries to allocate wireless resources to the legitimate users, stabilize the system, and minimize the secrecy outage probability. A stochastic network optimization framework is used to decompose the problem, and an online algorithm is proposed. We further consider a related problem, discuss the optimal solution, and show that the proposed algorithm cannot lead to optimal solution in some scenarios. By comparing the offline algorithm with our first algorithm, we further propose a second refined online algorithm, which is an optimal one. Extensive simulations are conducted to show the impact of the information arrival rate and the channel conditions on the system secrecy outage probability. These observations provide important insights and guidelines for the design and resource management of future wireless networks using secure communication technologies.
Autors: Xuan Wang;Yi Chen;Lin Cai;Jianping Pan;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 6449 - 6460
Publisher: IEEE
 
» Minimizing Torque Ripple of Highly Saturated Salient Pole Synchronous Machines by Applying DB-DTFC
Abstract:
Deadbeat-direct torque and flux control is a flux-observer-based high-bandwidth digital closed-loop torque control law that achieves the commanded torque at the end of each switching period. When flux estimation is accurate, instantaneous torque is fed back and undesirable pulsating torque is inherently minimized. This study presents real-time flux-observer-based torque ripple estimation of a highly nonlinear synchronous reluctance machine. Saturation and cross saturation are incorporated directly into the control law, and are considered in each switching period. Deadbeat torque response and torque ripple reduction is demonstrated experimentally. Finite element method simulations validate the torque ripple minimization.
Autors: Michael Saur;Daniel E. Gaona Erazo;Jelena Zdravkovic;Bastian Lehner;Dieter Gerling;Robert D. Lorenz;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3643 - 3651
Publisher: IEEE
 
» Minimum Flow Time in a Tandem Two-Server Fluid Network
Abstract:
We consider a tandem two-server fluid network with two fluid types. Each server in the network has two buffers, one for each fluid, and the capacity of each server can be shared among the fluids. An initial amount of fluids is to be processed by both servers and drained through the system. We determine the processing rates for which the servers' capacity is optimally shared, with the objective of minimizing the total flow time. Three cases of the optimal strategy are discussed.
Autors: Yossef Luzon;Eugene Khmelnitsky;Yariv Marmor;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3540 - 3545
Publisher: IEEE
 
» Minimum Implant Area-Aware Placement and Threshold Voltage Refinement
Abstract:
Threshold voltage assignment is a very effective technique to reduce leakage power consumption in modern integrated circuit design. As feature size continues to decrease, the layout constraints [called minimum implant area (MinIA) constraints] on the implant area, which determines the threshold voltage of a device, are becoming increasingly difficult to satisfy. It is necessary to take these constraints into consideration during the placement stage. In this paper, we propose to resolve the MinIA constraint violations of a given placement by performing simultaneous detailed placement and threshold voltage refinement. We first present an optimal and efficient mixed integer-linear programming (MILP)-based algorithm to handle intrarow MinIA constraints. We then extend the MILP-based algorithm to handle both inter-row and intrarow MinIA constraints. Both of our algorithms guarantee to fix all MinIA constraint violations. Experimental results demonstrate that our algorithms only perturb the original placement and threshold voltage assignment solutions minimally to eliminate all violations and are fast in practice.
Autors: Wai-Kei Mak;Wan-Sin Kuo;Shi-Han Zhang;Seong-I. Lei;Chris Chu;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jul 2017, volume: 36, issue:7, pages: 1103 - 1112
Publisher: IEEE
 
» Minimum Sparsity of Unobservable Power Network Attacks
Abstract:
Physical security of power networks under power injection attacks that alter generation and loads is studied. The system operator employs Phasor Measurement Units (PMUs) for detecting such attacks, while attackers devise attacks that are unobservable by such PMU networks. It is shown that, given the PMU locations, the solution to finding the sparsest unobservable attacks has a simple form with probability one, namely, , where is defined as the vulnerable vertex connectivity of an augmented graph. The constructive proof allows one to find the entire set of the sparsest unobservable attacks in polynomial time. Furthermore, a notion of the potential impact of unobservable attacks is introduced. With optimized PMU deployment, the sparsest unobservable attacks and their potential impact are evaluated numerically for the IEEE 30, 57, 118 and 300-bus systems and the Polish 2383, 2737 and 3012-bus systems. It is observed that, as more PMUs are added, the maximum potential impact among all the sparsest unobservable attacks drops quickly until it reaches the minimum sparsity.
Autors: Yue Zhao;Andrea Goldsmith;H. Vincent Poor;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3354 - 3368
Publisher: IEEE
 
» Mirror Mirror on the Wall... An Unobtrusive Intelligent Multisensory Mirror for Well-Being Status Self-Assessment and Visualization
Abstract:
A person's well-being status is reflected by their face through a combination of facial expressions and physical signs. The SEMEOTICONS project translates the semeiotic code of the human face into measurements and computational descriptors that are automatically extracted from images, videos, and three-dimensional scans of the face. SEMEOTICONS developed a multisensory platform in the form of a smart mirror to identify signs related to cardio-metabolic risk. The aim was to enable users to self-monitor their well-being status over time and guide them to improve their lifestyle. Significant scientific and technological challenges have been addressed to build the multisensory mirror, from touchless data acquisition, to real-time processing and integration of multimodal data.
Autors: Pedro Henriquez;Bogdan J. Matuszewski;Yasmina Andreu-Cabedo;Luca Bastiani;Sara Colantonio;Giuseppe Coppini;Mario D’Acunto;Riccardo Favilla;Danila Germanese;Daniela Giorgi;Paolo Marraccini;Massimo Martinelli;Maria-Aurora Morales;Maria Antoniett
Appeared in: IEEE Transactions on Multimedia
Publication date: Jul 2017, volume: 19, issue:7, pages: 1467 - 1481
Publisher: IEEE
 
» Mitigating Large Errors in WiFi-Based Indoor Localization for Smartphones
Abstract:
Although WiFi fingerprint-based indoor localization is attractive, its accuracy remains a primary challenge, especially in mobile environments. Existing approaches either appeal to physical layer information or rely on extra wireless signals for high accuracy. In this paper, we revisit the received signal strength (RSS) fingerprint-based localization scheme and reveal crucial observations that act as the root causes of localization errors, yet are surprisingly overlooked or not adequately addressed in previous works. Specifically, we recognize access points’ (APs) diverse discrimination for fingerprinting a specific location, observe the RSS inconsistency caused by signal fluctuations and human body blockages, and uncover the transitional fingerprint problem on commodity smartphones. Inspired by these insights, we devise a discrimination factor to quantify different APs’ discrimination, incorporate robust regression to tolerate outlier measurements, and reassemble different normal fingerprints to cope with transitional fingerprints. Integrating these techniques in a unified system, we propose DorFin, i.e., a novel scheme of fingerprint generation, representation, and matching, which yields remarkable accuracy without incurring extra cost. Extensive experiments in three campus buildings demonstrate that DorFin  achieves a mean error of 2.5 m and, more importantly, decreases the 95th percentile error under 6.2 m, both significantly outperforming existing approaches.
Autors: Chenshu Wu;Zheng Yang;Zimu Zhou;Yunhao Liu;Mingyan Liu;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 6246 - 6257
Publisher: IEEE
 
» Mitigating NLD for Wireless Networks: Effect of Nonlinear Power Amplifiers on Future Wireless Communication Networks
Abstract:
Efficient utilization of limited bandwidth with high-data-rate transmission while serving a large number of users is a prime requirement for present and future wireless communication systems. To meet this rising demand, orthogonal frequency-division multiplexing (OFDM) and cooperative communication have emerged as promising solutions due to their robustness in severely degraded channel conditions, link reliability, and spectral efficiency. Both OFDM and cooperative systems have challenged RF front-end specifications such as bandwidth and power-efficiency requirements for end users as well as for the base station due to the high peak-to-average power ratio (PAPR). In present and future communication systems, the power amplifier (PA) is a key component at the transmitter. To obtain maximum power efficiency, the PA is operated near its saturation point, which leads to nonlinear distortion (NLD), which is further exaggerated due to the high PAPR of the input signal. This NLD is expected to increase in future fifth-generation (5G) communication networks, due to the use of large bandwidth at millimeter-wave (mmW) frequencies.
Autors: Praveen Kumar Singya;Nagendra Kumar;Vimal Bhatia;
Appeared in: IEEE Microwave Magazine
Publication date: Jul 2017, volume: 18, issue:5, pages: 73 - 90
Publisher: IEEE
 
» Mitigation of Sampling Errors in VCO-Based ADCs
Abstract:
Voltage-controlled-oscillator-based analog-to-digital converter (ADC) is a scaling-friendly architecture to build ADCs in fine-feature complimentary metal-oxide-semiconductor processes. Lending itself to an implementation with digital components, such a converter enables design automation with existing digital CAD hence reducing design and porting costs compared with a custom design flow. However, robust architectures and circuit techniques that reduce the dependence of performance on component accuracy are required to achieve good performance while designing converters with low accuracy components like standard cells in deeply-scaled processes. This paper investigates errors resulting from the sampling of a fast switching multi-phase ring oscillator output. A scheme employing ones-counters is proposed to encode the sampled ring oscillator code into a binary representation, which is resilient to a class of sampling induced errors modeled by the temporal reordering of the transitions in the ring. In addition to correcting errors caused by deterministic reordering, proposed encoding suppresses conversion errors in the presence of arbitrary reordering patterns that may result from automatic place-and-route in wire-delay dominated processes. The error suppression capability of the encoding is demonstrated using MATLAB simulation. The proposed encoder reduces the error caused by the random reordering of six subsequent bits in the sampled signal from 31 to 2 LSBs for a 31-stage oscillator.
Autors: Vishnu Unnikrishnan;Mark Vesterbacka;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jul 2017, volume: 64, issue:7, pages: 1730 - 1739
Publisher: IEEE
 
» Mobile Service Selection for Composition: An Energy Consumption Perspective
Abstract:
Due to the limits of battery capacity of mobile devices, how to select cloud services to invoke in order to reduce energy consumption in mobile environments is becoming a critical issue. This paper addresses the problem of mobile service selection for composition in terms of energy consumption. It formally models this problem and constructs energy consumption computation models. Energy consumption aggregation rules for composite services with different structures are presented. It adopts the genetic algorithm to resolve it. A replanning mechanism is also proposed to deal with the changeable conditions and user behavior. A series of experiments are conducted to evaluate the performance of our method. The results show that our service selection method significantly outperforms traditional methods. Even if the conditions or user behavior is changeable, this method is still effective to recommend services. Moreover, the service selection method performs good scalability as the experimental scale increases.
Autors: Shuiguang Deng;Hongyue Wu;Wei Tan;Zhengzhe Xiang;Zhaohui Wu;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jul 2017, volume: 14, issue:3, pages: 1478 - 1490
Publisher: IEEE
 
» Mode Behavior of VCSELs With Impurity-Induced Disordering
Abstract:
This letter explores the modal behavior of oxide-confined vertical-cavity surface-emitting lasers (VCSELs) with varying emission apertures defined by impurity-induced disordering (IID) via closed ampoule zinc diffusion. A 1-D plane wave propagation method is used to calculate the mirror loss as a function of IID strength and depth. The devices are fabricated with masked areas ranging from approximately 70%–110% of the oxide aperture defining an unmodified emission aperture designed to overlap mainly with the fundamental mode. An analysis of the transverse mode lasing characteristics and mode-dependent thermal characteristics demonstrates a decrease in thermal performance associated with the increasing overlap between the IID ring and supported optical modes of the VCSEL cavity. A single-mode output power of 1.6 mW with over 30 dBm side-mode suppression ration is achieved from a device with an IID-defined output aperture of approximately . The optimal IID emission aperture to oxide aperture ratio for maximizing the single-fundamental-mode output power is experimentally measured.
Autors: Thomas O’Brien;Benjamin Kesler;Saoud Al Mulla;John M. Dallesasse;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jul 2017, volume: 29, issue:14, pages: 1179 - 1182
Publisher: IEEE
 
» Model Order Reduction of Electrical Machines With Multiple Inputs
Abstract:
In this paper, proper orthogonal decomposition (POD) method is employed to build a reduced-order model from a high-order nonlinear permanent magnet synchronous machine model with multiple inputs. Three parameters are selected as the multiple inputs of the machine. These parameters are terminal current, angle of the terminal current, and rotation angle. To produce the lower-rank system, snapshots or instantaneous system states are projected onto a set of orthonormal basis functions with small dimension. The reduced model is then validated by comparing the vector potential, flux density distribution, and torque results of the original model, which indicates the capability of using the POD method in the multivariable input problems. The developed methodology can be used for fast simulations of the machine.
Autors: Mehrnaz Farzamfar;Anouar Belahcen;Paavo Rasilo;Stéphane Clénet;Antoine Pierquin;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3355 - 3360
Publisher: IEEE
 
» Model Parameter Identification for Lithium Batteries Using the Coevolutionary Particle Swarm Optimization Method
Abstract:
This paper uses the coevolutionary particle swarm optimization (CPSO) method to identify battery parameters. A parameter identification window (PIW), which has the features of a fixed data length and real-time response, is used to store a piece of data that indicates the battery operation at the current moment. CPSO uses the data in the PIW to dynamically identify the battery parameters. Each equivalent circuit model (ECM) parameter uses a separate parameter particle swarm (PPS) to optimize their values. In every algorithm cycle, each particle in every PPS only evolves one step. The currently evolved PPS uses the current optimal values of the other PPS in CPSO to evaluate all of the particles and to find the best particle. Every PPS is scheduled by the CPSO, dynamically evolves one by one, and converges in real time to its optimal value, which is an ECM parameter. Real battery data are used to test the algorithm. The experimental results indicate that the fluctuation patterns of the open circuit voltage (OCV) are accurately identified. For the different algorithm parameters, the identification results for the OCV have good consistency, and the deviations between the identification results are less than 5 mV most of the time.
Autors: Zhihao Yu;Linjing Xiao;Hongyu Li;Xuli Zhu;Ruituo Huai;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5690 - 5700
Publisher: IEEE
 
» Model Reduction by Differential Balancing Based on Nonlinear Hankel Operators
Abstract:
In this paper, we construct balancing theory for nonlinear systems in the contraction framework. First, we define two novel controllability and observability functions via prolonged systems. We analyze their properties in relation to controllability and observability, and use them for so-called differential balancing, and its application to model order reduction. One of the main contribution of this paper is showing that differential balancing has close relationships with the Fréchet derivative of the nonlinear Hankel operator. Inspired by [3], we provide a generalization in order to have a computationally more feasible method. Moreover, error bounds for model reduction by generalized balancing are provided.
Autors: Yu Kawano;Jacquelien M. A. Scherpen;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3293 - 3308
Publisher: IEEE
 
» Model-Based Calibration for Magnetic Manipulation
Abstract:
Model-based calibration of a magnetic workspace not only provides a smooth representation of the field and its gradient matrix, but also uses physical constraints to smooth the calibration measurements. This paper presents the first model-based technique to calibrate a magnetic manipulation system by using nonlinear least squares to solve for a scalar potential for each source. The performance of the method is verified by comparison to numerical finite element simulation and a case study calibration of a real system, where it is able to achieve an value of 0.9997. Furthermore, the analytical representations for the first three spatial derivatives of a spherical multipole expansion are provided for convenience, which correspond to the torque, force, and force-spatial-rate-of-change on a magnetic dipole in the workspace.
Autors: Andrew J. Petruska;Janis Edelmann;Bradley J. Nelson;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jul 2017, volume: 53, issue:7, pages: 1 - 6
Publisher: IEEE
 
» Model-Based Dispatch Strategies for Lithium-Ion Battery Energy Storage Applied to Pay-as-Bid Markets for Secondary Reserve
Abstract:
Due to their decreasing cost, lithium-ion batteries (LiB) are becoming increasingly attractive for grid-scale applications. In this paper, we investigate the use of LiB for providing secondary reserve and show how the achieved cost savings could be increased by using model-based optimization techniques. In particular, we compare a maximum use dispatch strategy with two different cost-minimizing strategies. For the estimation of state-dependent battery usage cost, we combine an existing electro-thermal LiB model of a mature lithium-iron-phosphate battery cell with corresponding semiempirical calendar and cycle aging models. We estimate the benefit of storage operation from the system operator's point of view by gauging the avoided cost of activated reserve. Our evaluation is based on two years worth of data from the German reserve market. The proposed cost minimizing dispatch strategies yield significantly better results than a dispatch strategy that maximizes battery utilization.
Autors: Christoph Goebel;Holger Hesse;Michael Schimpe;Andreas Jossen;Hans-Arno Jacobsen;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 2724 - 2734
Publisher: IEEE
 
» Modeling and Analysis of the Reliability of      Digital Networked Control Systems   Considering Networked Degradations
Abstract:
Digital networked control systems are of growing importance in safety-critical systems and perform indispensable function in most complex systems today. Networked degradations such as transmission delay and packet dropout cause such systems to fail to satisfy performance requirements, and eventually affect the overall reliability. It is necessary to get a model to verify and evaluate the system reliability in early design phase, prior to its implementation. However, existing probabilistic models only provide partial descriptions of such coupled networks and control system. In this paper, a new stochastic model represented by linear discrete-time approach is proposed, considering data packet transmissions in both channels: controller-to-actuator and sensor-to-controller. Different from pervious works, the historical behaviors of networked degradations are modeled by multistate Markov chains with uncertainties, releasing the assumption that faults of all periods are independent of each other. The concept of domain requirements for such systems is considered here, contributing to the integration of control and reliability engineering. Methodologies for quantitatively assessing the reliability of the single- and sequential-control goal are derived from the Monte Carlo method. An example of an industrial heat exchanger digital networked control system is provided to illustrate the effectiveness of the model and method.
Autors: Huadong Mo;Wei Wang;Min Xie;Junlin Xiong;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jul 2017, volume: 14, issue:3, pages: 1491 - 1503
Publisher: IEEE
 
» Modeling and Characterization of Slitted Parallel-Plate Waveguide With Applications for Slit-Based Planar Structures
Abstract:
This paper presents a rigorous scattering model of an infinite slit on a dielectric-loaded parallel-plate waveguide with an oblique incident TEM wave. The dyadic Green’s functions of an equivalent line source are derived first and then applied to solve the scattered fields in terms of reflection, transmission, and radiation. Special treatment with PEC/PMC symmetry is employed for fast and accurate calculation. The proposed model was carefully validated by the full-wave simulator with excellent agreement. Some interesting scattering phenomena are found and emphasized, as they are crucial in explaining the special features of slit-based planar structures. In this paper, we demonstrate the presented model for the analysis and physical explanation of unique features found in a slitted substrate integrated waveguide, grounded coplanar waveguide, and grounded coplanar stripline. The proposed model provides a simple and effective approach for the design of potential slit-based planar circuits and antennas based on the presented structures in this paper.
Autors: Yao-Wen Hsu;Yi-Cheng Lin;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2017, volume: 65, issue:7, pages: 2228 - 2239
Publisher: IEEE
 
» Modeling and Experimental Verification of a 100% Stator Ground Fault Protection Based on Adaptive Third-Harmonic Differential Voltage Scheme for Synchronous Generators
Abstract:
In this paper, a novel adaptive stator-ground fault protection scheme based on third-harmonic differential voltages is implemented on a lab scale synchronous generator. The lab scale generator is used to emulate the fault characteristics of industrial generators along the stator windings. Simulations based on finite element analysis methods were used to design and tune the laboratory testbed. Experimental results prove the expected fault characteristics as well as fault detection capability of the adaptive stator-ground fault protection scheme.
Autors: Khaled Al Jaafari;Amir Negahdari;Hamid A. Toliyat;Nader Safari-Shad;Russ Franklin;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3379 - 3386
Publisher: IEEE
 
» Modeling and Joint Mitigation of TX and RX Nonlinearity-Induced Receiver Desensitization
Abstract:
In this paper, we provide detailed modeling of the spurious intermodulation distortion products appearing in the own receiver (RX) operating band as a result of coexisting transmitter (TX) and RX nonlinearities with noncontiguous carrier aggregation transmissions. Furthermore, an efficient digital front-end signal processing technique is proposed, which can flexibly mitigate the resulting RX in-band self-interference caused either by individual or simultaneously coexisting TX and RX nonlinearities. The technique is based on accurately estimating the effective leakage channel that models the nonlinearities of the TX and RX chains and the duplexer filters characteristics. In the parameter estimation stage, an observation RX chain is adopted for separately estimating the TX passband leakage response, which facilitates efficient joint estimation and regeneration of the TX- and RX-induced self-interference. In the online digital cancellation, the actual transmit data are used in conjunction with the estimated channel responses to generate a replica of the overall nonlinear self-interference, which is subsequently suppressed by subtracting it from the actual observation. In general, the proposed technique can efficiently estimate and suppress the self-interference at arbitrary spurious sub-bands located at the RX band. The performance evaluations with comprehensive numerical simulations and practical RF measurements indicate highly accurate and efficient operation, with up to 28 dB of measured self-interference suppression.
Autors: Adnan Kiayani;Lauri Anttila;Marko Kosunen;Kari Stadius;Jussi Ryynänen;Mikko Valkama;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2017, volume: 65, issue:7, pages: 2427 - 2442
Publisher: IEEE
 
» Modeling and Simulation Study for Solid Particles Detection in Gas–Oil Pipelines Using Field Free Line in Magnetic Particle Imaging and Its Hardware Realization
Abstract:
This paper suggests a new magnetic particle imaging (MPI) technique for 2-D tomographic imaging to detect the presence of flowing solid particles (i.e., black powder, which consist of paramagnetic nanoparticles) passing through gas–oil pipelines. The hardware consists of a ring of a modified Halbach array of 24 permanent magnets, in addition to two surrounding Helmholtz coil pairs, and a receiving coil, which are evenly distributed across a cross section of the probe. With the application of static and dynamically moving drive fields, the MPI utilizes the full benefit of superparamagnetic iron oxide nanoparticles (SPIONs) by providing a linear response when they are exposed to a relatively low magnetic field and no response when they are saturated. The scanning of region of interest with the field-free line (FFL) instead of the field-free point (FFP) is motivated by the fact that a high-intensity dc current is required for FFP, which is not tolerated in oil–gas pipelines where the maximal current should not exceed few amperes. With the presence of an oscillatory magnetic field, SPIONs react with a nonlinear magnetization response, which is further measured by the receiving coil. A 2-D image reconstruction is then performed using the frequency-based image reconstruction process. The hardware design, specifically the sizing of permanent magnets with regard to their relative position and dimensions, was refined following an optimization technique based on the particle swarm optimization technique. The assessment of the system using finite-element method indicates that the system can reconstruct the 2-D profile of the SPION with a mean absolute error of prediction of less than 4% and 12% using FFL and FFP methods, respectively.
Autors: Mohit Kalra;Mahmoud Meribout;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jul 2017, volume: 53, issue:7, pages: 1 - 8
Publisher: IEEE
 
» Modeling of Type 3 Wind Turbines With df/dt Inertia Control for System Frequency Response Study
Abstract:
A model for Type 3 wind turbines (WTs) with typical df/dt inertia control is developed for studying frequency dynamics in power systems. A simplified small-signal Type 3 WT model with df/dt control is first constructed based on the mass-spring-damping concept, such that the physical properties and frequency response of a Type 3 WT can be clearly understood, besides the frequency-domain expressions of the available inertia and the corresponding damping coefficient can be directly derived. The manifested inertia is apparently controllable and frequency-dependent, but differs from the constant inertia featured in a conventional synchronous generator (SG). Furthermore, the frequency response model of a generic two-machine system, composed of an SG and an aggregate Type 3 WTs, is established. The model synthetically considers the effects of the WTs’ different controller parameters, operating points, and the SG's governor response on system frequency characteristics. Then, time-domain simulations on the studied two-machine system are performed in MATLAB/Simulink. The simulated results verify that the proposed model is effective for analyzing system frequency dynamics, and that the test system frequency characteristics can be improved based on tuning the mass-spring- damping coefficients of Type 3 WTs.
Autors: Jiabing Hu;Li Sun;Xiaoming Yuan;Shuo Wang;Yongning Chi;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 2799 - 2809
Publisher: IEEE
 
» Modeling Protection Systems in Time-Domain Simulations: A New Method to Detect Mis-Operating Relays for Unstable Power Swings
Abstract:
Large power system disturbances can cause stable or unstable power swings. Unstable power swings result in generator pole slipping. A generator or group of generators may accelerate or decelerate, leading to voltage depression at the electrical center along with generator tripping. This voltage depression may cause protective relay mis-operation and unintentional separation of the system. In order to avoid unintentional islanding, the potentially mis-operating relays should be blocked from tripping. This paper proposes a novel method to determine the location of the mis-operating relays at the planning phase. Blocking these mis-operating relays, combined with an appropriate islanding scheme, help avoid a system-wide collapse. The proposed method is tested on data from the Western Electricity Coordinating Council. A triple line outage of the California-Oregon Intertie is studied. The electrical center is determined and appropriate out-of-step blocking schemes are identified. The results show that the correct design of out-of-step protective relays improves the dynamic performance of the power system and causes less fluctuations in voltage and frequency throughout the system.
Autors: Mojdeh Abdi-Khorsand;Vijay Vittal;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2017, volume: 32, issue:4, pages: 2790 - 2798
Publisher: IEEE
 
» Modeling Satellite Precipitation Errors Over Mountainous Terrain: The Influence of Gauge Density, Seasonality, and Temporal Resolution
Abstract:
This paper contributes to the predictive understanding of satellite precipitation estimation errors over complex terrain, which is fundamental to the development of error models for improving hydrological applications. This paper focuses on the Trentino-Alto Adige region of the eastern Italian Alps. Rainfall observations over a 10-year period (2000–2009) from a dense rain gauge network in the region are used as reference precipitation. A number of satellite precipitation error properties (probability of detection, false alarm rates, missed events, spatial correlation of the error, and hit biases) are investigated in terms of seasonality, satellite algorithm, rainfall intensity, gauge density, and temporal resolution dependencies. These error parameters are typically used in error models (e.g., SREM2D) and provide the basis for enhancing error scheme development. Three widely used satellite-based precipitation products are employed: 1) the Climate Prediction Center morphing product; 2) the precipitation estimation from remotely sensed imagery using artificial neural networks; and 3) the Tropical Rainfall Measuring Mission multisatellite precipitation analysis 3B42 near-real-time product. The three products show similar performances, with larger errors during the warm season, characterized by convective storms, and less variability in the cold season, characterized by more organized stratiform systems. Lower biases are depicted at the daily scale with respect to the 3-hourly resolution. The SREM2D error model has the ability to correct the satellite precipitation products, even though attention is needed for potential systematic errors when applying the calibrated model to independent periods or regions.
Autors: Viviana Maggioni;Efthymios I. Nikolopoulos;Emmanouil N. Anagnostou;Marco Borga;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jul 2017, volume: 55, issue:7, pages: 4130 - 4140
Publisher: IEEE
 
» Modeling the Impact of Phase Noise on the Performance of Crystal-Free Radios
Abstract:
We propose a crystal-free radio receiver exploiting a free-running oscillator as a local oscillator (LO) while simultaneously satisfying the 1% packet error rate (PER) specification of the IEEE 802.15.4 standard. This results in significant power savings for wireless communication in millimeter-scale microsystems targeting Internet of Things applications. A discrete time simulation method is presented that accurately captures the phase noise (PN) of a free-running oscillator used as an LO in a crystal-free radio receiver. This model is then used to quantify the impact of LO PN on the communication system performance of the IEEE 802.15.4 standard compliant receiver. It is found that the equivalent signal-to-noise ratio is limited to ~8 dB for a 75- ring oscillator PN profile and to ~10 dB for a 240- LC oscillator PN profile in an AWGN channel satisfying the standard’s 1% PER specification.
Autors: Osama Khan;Brad Wheeler;Filip Maksimovic;David Burnett;Ali M. Niknejad;Kris Pister;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jul 2017, volume: 64, issue:7, pages: 777 - 781
Publisher: IEEE
 
» Modeling, Analysis, and Experimental Validation of Clock Drift Effects in Low-Inertia Power Systems
Abstract:
Clock drift in digital controllers is of great relevance in many applications. Since almost all real clocks exhibit drifts, this applies in particular to networks composed of several individual units, each of which being operated with its individual clock. In the present paper, we demonstrate via extensive experiments on a microgrid in the megawatt range that clock drifts may impair frequency synchronization in low-inertia power systems. The experiments also show that—in the absence of a common clock—the standard model of an inverter as an ideal voltage source does not capture this phenomenon. As a consequence, we derive a suitably modified model of an inverter-interfaced unit that incorporates the phenomenon of clock drifts. By using the derived model, we investigate the effects of clock drifts on the performance of droop-controlled grid-forming inverters with regard to frequency synchronization and active power sharing. The modeling and analysis is validated via extensive experiments on a microgrid in the megawatt range.
Autors: Johannes Schiffer;Christian A. Hans;Thomas Kral;Romeo Ortega;Jörg Raisch;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5942 - 5951
Publisher: IEEE
 
» Modernizing Distribution System Restoration to Achieve Grid Resiliency Against Extreme Weather Events: An Integrated Solution
Abstract:
Recent severe power outages caused by extreme weather hazards have highlighted the importance and urgency of improving the resilience of the electric power grid. As the distribution grids still remain vulnerable to natural disasters, the power industry has focused on methods of restoring distribution systems after disasters in an effective and quick manner. The current distribution system restoration practice for utilities is mainly based on predetermined priorities and tends to be inefficient and suboptimal, and the lack of situational awareness after the hazard significantly delays the restoration process. As a result, customers may experience an extended blackout, which causes large economic loss. On the other hand, the emerging advanced devices and technologies enabled through grid modernization efforts have the potential to improve the distribution system restoration strategy. However, utilizing these resources to aid the utilities in better distribution system restoration decision making in response to extreme weather events is a challenging task. Therefore, this paper proposes an integrated solution: a distribution system restoration decision support tool designed by leveraging resources developed for grid modernization. First, we review the current distribution restoration practice and discuss why it is inadequate in response to extreme weather events. Then, we describe how the grid modernization efforts could benefit distribution system restoration, and we propose an integrated solution in the form of a decision support tool to achieve the goal. The advantages of the solution include improving situational awareness of the system damage status and facilitating survivability for customers. The paper provides a comprehensive review of how the existing methodologies in the literature could be leveraged to achieve the key advantages. The benefits of the developed system restoration decision support tool include the optimal and efficient allocation of repair cre- s and resources, the expediting of the restoration process, and the reduction of outage durations for customers, in response to severe blackouts due to extreme weather hazards.
Autors: Chen Chen;Jianhui Wang;Dan Ton;
Appeared in: Proceedings of the IEEE
Publication date: Jul 2017, volume: 105, issue:7, pages: 1267 - 1288
Publisher: IEEE
 
» Modified Frei-Chen Operator-Based Infrared and Visible Sensor Image Fusion for Real-Time Applications
Abstract:
Real-time fusion of images acquired from multiple sensors is significant in various fields, including military and aviation, to reduce the uncertainty in the acquired images and for wider temporal and spatial coverage. Current approaches to multi-sensor image fusion have a high computational complexity and difficult to implement in hardware. This paper presents a method based on two-scale decomposition and modified Frie-Chen operators to fuse images acquired from infrared and visible image sensors and its corresponding hardware implementation. The proposed method achieves 48%, 15%, and 100% improvements in total edge transfers, structural similarity, and night vision contrast, respectively, with respect to those of the latest publications known to the authors. The corresponding hardware architecture, synthesized using the Xilinx tool, is shown to consume 4% of the resources in the Virtex 4 field programmable gate array (FPGA-xc4vlx200). The proposed architecture has one unit of throughput per clock cycle and is able to process 30 high definition images/sec. The proposed architecture is also analyzed using the synopsis design vision tool with the 90-nm UMC standard complementary metal–oxide–semiconductor cell library. It is found that the architecture consumes 251.6 mW of power and has an area equivalent to 580K NAND2 gates. The lower hardware resource requirement and support of parallelism and pipelining make the proposed algorithm suitable for low-power, real-time image fusion applications.
Autors: Ashutosh Mishra;Sudipta Mahapatra;Swapna Banerjee;
Appeared in: IEEE Sensors Journal
Publication date: Jul 2017, volume: 17, issue:14, pages: 4639 - 4646
Publisher: IEEE
 
» Modified Sagnac Loop Coherent Phase Modulated RF Photonic Link With an ACP-OPLL
Abstract:
The first Sagnac loop coherent phase modulated RF photonic link employing an ACP-OPLL linear phase demodulator was presented. This structure demonstrated stable signal transmission over a 1-km long coherent RF photonic link. Except for optical loss of the long optical fiber, no penalties in the noise and linearity performance were observed.
Autors: Shilei Jin;Longtao Xu;Yifei Li;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jul 2017, volume: 29, issue:14, pages: 1139 - 1142
Publisher: IEEE
 
» Modular Reluctance Network Simulation of a Linear Permanent-Magnet Vernier Machine Using New Mesh Generation Methods
Abstract:
Reluctance network (RN) method is suitable for the modeling of complex magnetic field. In traditional RN models, the meshes cover the whole cross-sectional area of the electric machines, so much time is required. In order to improve the modeling efficiency, a new modular RN structure and two mesh generation methods are proposed in this paper. The size and shape of the mesh elements are identical and their permeance calculations are unified. These characteristics can greatly enhance the modeling flexibility of the RN. Then, the proposed methods and the simple magnetic circuit method are combined to analyze the performances of a linear permanent magnet vernier machine. Finally, finite-element analysis and experimental tests are carried out to evaluate the proposed method. Results show that the proposed method has high accuracy and high modeling speed.
Autors: Guohai Liu;Shan Jiang;Wenxiang Zhao;Qian Chen;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5323 - 5332
Publisher: IEEE
 
» Monitoring Journal-Bearing Faults: Making Use of Motor Current Signature Analysis for Induction Motors
Abstract:
Most of the failures in oil-lubricated journal bearings are associated with mechanical instabilities produced by lubrication-system problems or bearing wear and result in increased shaft vibration. Therefore, monitoring the journal-bearing condition in the field relies mainly on the analysis of proximity-probe or accelerometer signals. However, not all motors with journal bearings are equipped with such mechanical sensors due to cost or environmental restrictions. In this article, we evaluate the feasibility of applying motor current signature analysis (MCSA) for the remote monitoring of mechanical instabilities in journal bearings produced by oil-whirl and bearing-clearance problems. In addition, we present a small-scale journal-bearing test setup that can be implemented in low-voltage motors for testing journal-bearing faults under controlled conditions. An experimental study on a sealless fuel-pump motor operating in the field and on the custom-built journal-bearing motor test setup shows that MCSA can remotely monitor journal-bearing oil whirl and excessive clearance to prevent motor failure. The results of vibration analysis are also presented for comparative evaluation.
Autors: Junyeong Jung;Yonghyun Park;Sang Bin Lee;Chang-Hee Cho;Kwonhee Kim;Ernesto J. Wiedenbrug;Mike Teska;
Appeared in: IEEE Industry Applications Magazine
Publication date: Jul 2017, volume: 23, issue:4, pages: 12 - 21
Publisher: IEEE
 
» Monolithically Integrated Microheater for On-Chip Annealing of Oxide Defects
Abstract:
An on-chip annealing system based on a monolithically integrated microheater is presented. As the test chip, complementary metal–oxide–semiconductor transistors based on 22-nm node are fabricated using commercial foundry technology. Then, the microheater is integrated on a thinned wafer backside by shadow mask patterning. The thermal power efficiency was examined experimentally and verified by numerical simulation. The system on microheater provides 90% restoration of integrity of the gate oxide at 200 °C for 10 min and full recovery around 2 h. Since the backside microheater fabrication is independent of the front-side circuitry, the on-chip annealing scheme can be implemented on any arbitrary commercial-off-the-shelf device as a generic approach.
Autors: Jin-Woo Han;Ricardo Peterson;Dong-II Moon;Debbie G. Senesky;M. Meyyappan;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2017, volume: 38, issue:7, pages: 831 - 834
Publisher: IEEE
 
» Motion Control for Cylindrical Objects in Microscope's View Using a Projection Method— I: Collision Detection and Detach Control
Abstract:
This paper investigates collision detection between cylindrical or cylinder-enveloped components when mutual blocking occurs in the view of microscopes and detach control to separate objects if contact occurs. We use a projection method to convert two microscopic views to contours on a projection plane and to detect high-dimensional collision by studying the projection's relationships in low dimension. Eleven cases are totally categorized and 12 parameters are constructed for detection on the basis of relative postures and positions. Furthermore, we present a detach controller to handle with object contact according to collision status, objects’ main axis, and the computed contact position. Simulations and experiments are carried out to demonstrate the validity of the proposed method.
Autors: Dengpeng Xing;Fangfang Liu;Song Liu;De Xu;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5524 - 5533
Publisher: IEEE
 
» Motion-Homogeneous-Based Fast Transcoding Method From H.264/AVC to HEVC
Abstract:
With the popularity of high-efficiency video coding (HEVC) standard, a video server usually transcodes a video stream to HEVC for its higher compression ratio. In this paper, a fast H.264/advanced video coding (AVC) to HEVC transcoding method is proposed. In the HEVC encoding procedure, a coding unit (CU), which is a motion-homogeneous block, is first checked based on the analysis of the decoded information from H.264/AVC bit stream. Then, for motion-homogeneous blocks, CU depth and the corresponding prediction unit (PU) mode's early termination strategies are proposed based on the CU size and corresponding prior statistical knowledge. For non-motion-homogeneous blocks, a corresponding PU mode's early termination strategy is also proposed. Experimental results demonstrate the effectiveness of the proposed method.
Autors: Hui Yuan;Chenglin Guo;Ju Liu;Xu Wang;Sam Kwong;
Appeared in: IEEE Transactions on Multimedia
Publication date: Jul 2017, volume: 19, issue:7, pages: 1416 - 1430
Publisher: IEEE
 
» Multi-Antenna Wireless Legitimate Surveillance Systems: Design and Performance Analysis
Abstract:
To improve national security, government agencies have long been committed to enforcing powerful surveillance measures on suspicious individuals or communications. In this paper, we consider a wireless legitimate surveillance system, where a full-duplex multi-antenna legitimate monitor aims to eavesdrop on a dubious communication link between a suspicious pair via proactive jamming. Assuming that the legitimate monitor can successfully overhear the suspicious information only when its achievable data rate is no smaller than that of the suspicious receiver, the key objective is to maximize the eavesdropping non-outage probability by joint design of the jamming power, receive and transmit beamformers at the legitimate monitor. Depending on the number of receive/transmit antennas implemented, i.e., single-input single-output, single-input multiple-output, multiple-input single-output, and multiple-input multiple-output (MIMO), four different scenarios are investigated. For each scenario, the optimal jamming power is derived in a closed form and efficient algorithms are obtained for the optimal transmit/receive beamforming vectors. Moreover, low-complexity suboptimal beamforming schemes are proposed for the MIMO case. Our analytical findings demonstrate that by exploiting multiple antennas at the legitimate monitor, the eavesdropping non-outage probability can be significantly improved compared with the single-antenna case. In addition, the proposed suboptimal transmit zero-forcing scheme yields similar performance as the optimal scheme.
Autors: Caijun Zhong;Xin Jiang;Fengzhong Qu;Zhaoyang Zhang;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jul 2017, volume: 16, issue:7, pages: 4585 - 4599
Publisher: IEEE
 
» Multi-Attribute Vertical Handover Decision-Making Algorithm in a Hybrid VLC-Femto System
Abstract:
Due to the complementary natures of visible light communication (VLC) and radio frequency, a combined application is regarded as a promising approach of supporting both hyperspeed data transmission and reliable signal connectivity. Vertical handover (VHO) is critical for guaranteeing seamless service in such a heterogeneous network. This letter employs a family hybrid VLC-Femto system and proposes a VHO algorithm based on decision selection. Our approach considers multiple attributes, including dynamic network parameters and actual traffic preferences by utilizing analytic hierarchy process (AHP). Additionally, it can compensate for the weakness of classic AHP in comparing the criteria values of different candidates by applying a two-person cooperative game (CG) model. Finally, the rationality degree (RD) of each decision is calculated by combining the results of AHP and CG, and the decision with the higher RD is selected. The simulation results validate the superiority of the proposed AHP-CG VHO algorithm over existing schemes under various circumstances.
Autors: Shufei Liang;Yuexia Zhang;Bo Fan;Hui Tian;
Appeared in: IEEE Communications Letters
Publication date: Jul 2017, volume: 21, issue:7, pages: 1521 - 1524
Publisher: IEEE
 
» Multi-Frequency mmWave Massive MIMO Channel Measurements and Characterization for 5G Wireless Communication Systems
Abstract:
Most millimeter wave (mmWave) channel measurements are conducted with different configurations, which may have large impacts on propagation channel characteristics. In addition, the comparison of different mmWave bands is scarce. Moreover, mmWave massive multiple-input multiple-output (MIMO) channel measurements are absent, and new propagation properties caused by large antenna arrays have rarely been studied yet. In this paper, we carry out mmWave massive MIMO channel measurements at 11-, 16-, 28-, and 38-GHz bands in indoor environments. The space-alternating generalized expectation-maximization algorithm is applied to process the measurement data. Important statistical properties, such as average power delay profile, power azimuth profile, power elevation profile, root mean square delay spread, azimuth angular spread, elevation angular spread, and their cumulative distribution functions and correlation properties, are obtained and compared for different bands. New massive MIMO propagation properties, such as spherical wavefront, cluster birth-death, and non-stationarity over the antenna array, are validated for the four mmWave bands by investigating the variations of channel parameters. Two channel models are used to verify the measurements. The results indicate that massive MIMO effects should be fully characterized for mmWave massive MIMO systems.
Autors: Jie Huang;Cheng-Xiang Wang;Rui Feng;Jian Sun;Wensheng Zhang;Yang Yang;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jul 2017, volume: 35, issue:7, pages: 1591 - 1605
Publisher: IEEE
 
» Multi-Tracker Partition Fusion
Abstract:
We propose a decision-level approach to fuse the output of multiple trackers based on their estimated individual performance. The proposed approach is composed of three main steps. First, we group trackers into clusters based on the spatiotemporal pair-wise correlation of their short-term trajectories. Then, we evaluate performance based on reverse-time analysis with an adaptive reference frame and define the cluster with trackers that appear to be successfully following the target as the on-target cluster. Finally, the state estimations produced by trackers in the on-target cluster are fused to obtain the target state. The proposed fusion approach uses standard tracker outputs and can therefore combine various types of trackers. We tested the proposed approach with several combinations of state-of-the-art trackers and also compared it with individual trackers and other fusion approaches. The results show that the proposed approach improves the state estimation accuracy under multiple tracking challenges.
Autors: ObaidUllah Khalid;Juan Carlos SanMiguel;Andrea Cavallaro;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jul 2017, volume: 27, issue:7, pages: 1527 - 1539
Publisher: IEEE
 
» Multi-User Precoding and Channel Estimation for Hybrid Millimeter Wave Systems
Abstract:
In this paper, we develop a low-complexity channel estimation for hybrid millimeter wave (mmWave) systems, where the number of radio frequency (RF) chains is much less than the number of antennas equipped at each transceiver. The proposed mmWave channel estimation algorithm first exploits multiple frequency tones to estimate the strongest angle-of-arrivals (AoAs) at both base station (BS) and user sides for the design of analog beamforming matrices. Then, all the users transmit orthogonal pilot symbols to the BS along the directions of the estimated strongest AoAs in order to estimate the channel. The estimated channel will be adopted to design the digital zero-forcing (ZF) precoder at the BS for the multi-user downlink transmission. The proposed channel estimation algorithm is applicable to both the non-sparse and sparse mmWave channel environments. Furthermore, we derive a tight achievable rate upper bound of the digital ZF precoding with the proposed channel estimation algorithm scheme. Our analytical and simulation results show that the proposed scheme obtains a considerable achievable rate of fully digital systems, where the number of RF chains equipped at each transceiver is equal to the number of antennas. Besides, considering the effect of various types of errors, i.e., random phase errors, transceiver analog beamforming errors, and equivalent channel estimation errors, we derive a closed-form approximation for the achievable rate of the considered scheme. We illustrate the robustness of the proposed channel estimation and multi-user downlink precoding scheme against the system imperfection.
Autors: Lou Zhao;Derrick Wing Kwan Ng;Jinhong Yuan;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jul 2017, volume: 35, issue:7, pages: 1576 - 1590
Publisher: IEEE
 
» Multicell Three-Phase AC–DC Driver for HB-LED Lighting Applications
Abstract:
High-brightness light-emitting diodes (HB-LEDs) are becoming omnipresent across all aspects of illumination products, due to their incredible characteristics such as efficiency, reliability, long lifetime, controllability, etc. This paper proposes power conversion topologies to drive medium to high power HB-LEDs in three-phase power grids when these connections are available. For that reason, an evaluation of several drivers for medium to high power HB-LEDs in three-phase power grids is done. Moreover, a new topology is proposed, which complies with IEC 1000-3-2 Class C requirements, achieves high power factor, low total harmonic distortion, and the capability to have a flicker free behavior while disposing of the bulk capacitor and having galvanic isolation. The HB-LED driver is based on a modular approach with several cells working together with their inputs connected to the three-phase network and their outputs connected in parallel generating a dc output. Each one of these cells is a dc–dc converter operating as a loss free resistor. In order to validate the concept, a prototype has been built by the use of flyback converters operating in discontinuous conduction mode. Furthermore, it operates in the full range of the European three-phase line voltage, which varies between 380 and 420 V, and it supplies an output voltage of 48 V with maximum power of 90 W.
Autors: Ignacio Castro;Diego G. Lamar;Manuel Arias;Marta M. Hernando;Javier Sebastian;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3803 - 3813
Publisher: IEEE
 
» Multichannel Sequential Detection—Part I: Non-i.i.d. Data
Abstract:
We consider the problem of sequential signal detection in a multichannel system assuming that the number and location of signals are either unknown or only partially known a priori. We focus on the design and analysis of two sequential hypothesis tests: the generalized sequential likelihood ratio test and the mixture sequential likelihood ratio test. We develop an asymptotic theory for a general stochastic model, where the various data streams can be coupled and correlated, and the data in each stream can be dependent and non-identically distributed. Specifically, we show that the two proposed sequential detection procedures asymptotically minimize the expected sample size and even higher moments of the sample size in the class of hypothesis tests with given probabilities of errors under weak distributional assumptions. We also propose efficient importance sampling algorithms for estimating error probabilities of the sequential tests by Monte Carlo simulation. The general theory is illustrated with several practical examples, such as the detection of signals, in Gaussian hidden Markov models, white Gaussian noises with unknown intensity, and testing of the first-order autoregression’s correlation coefficient. Finally, we illustrate our asymptotic results and compare the two proposed procedures with a simulation study.
Autors: Georgios Fellouris;Alexander G. Tartakovsky;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jul 2017, volume: 63, issue:7, pages: 4551 - 4571
Publisher: IEEE
 
» Multidimensional Compression of ITS Data Using Wavelet-Based Compression Techniques
Abstract:
This paper explores the use of wavelet transform-based methods for ITS data compression. A methodology for structuring data and applying wavelet transform-based algorithms is proposed. The methodology provides the option of controlling the compression ratio at the cost of an acceptable distortion, visualizing data at different detail levels. With proper database management, this methodology will also allow faster data access without fully decompressing them. Given a high correlation of traffic data and knowing that the image data are compressed very well due to the inherent correlation of image pixels, the idea here is to restructure the traffic data, such that efficient image compression methods underlying modern image compression standards can be used. Three data structures are discussed: 1-D, 2-D, and 3-D. For a 1-D arrangement, different wavelets and decomposition levels were tested and analyzed for distortion levels in the data after decompression. The 2-D and 3-D data arrangements were compressed using embedded zero-tree wavelet and set partitioning in hierarchical trees algorithms, which are well-proved algorithms for compressing image data. A case study was performed using the traffic flow data from freeways in Las Vegas, Nevada. As could be expected, the compression ratio under the 3-D scheme has shown the best results. The 2-D and 3-D approaches yielded a 91% and 95.2% reduction ratios, respectively.
Autors: Shaurya Agarwal;Emma E. Regentova;Pushkin Kachroo;Himanshu Verma;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jul 2017, volume: 18, issue:7, pages: 1907 - 1917
Publisher: IEEE
 
» Multifunctional Piezopolymer Film Transducer for Structural Health Monitoring Applications
Abstract:
This paper describes the design of a multifunctional transducer for structural health monitoring (SHM) applications that integrates an interdigital piezoelectric transducer, used for Lamb wave generation and reception, a circular piezoelectric sensor, used for the detection and localization of low-velocity impacts, and a resistance temperature detector (RTD) in a single device. The three elements were fabricated on the same metallized piezoelectric polyvinylidene fluoride (PVDF) film using a laser etching process. Characterization of the resulting device proved the advantages of having different transducers on the same device, providing information useful to implement advanced SHM algorithms. Testing of the RTD highlighted some criticalities of the metallized PVDF film that prevented accurate temperature measurements due to spurious behavior under strain.
Autors: Pietro Giannelli;Andrea Bulletti;Lorenzo Capineri;
Appeared in: IEEE Sensors Journal
Publication date: Jul 2017, volume: 17, issue:14, pages: 4583 - 4586
Publisher: IEEE
 
» Multilevel Contextual 3-D CNNs for False Positive Reduction in Pulmonary Nodule Detection
Abstract:
Objective: False positive reduction is one of the most crucial components in an automated pulmonary nodule detection system, which plays an important role in lung cancer diagnosis and early treatment. The objective of this paper is to effectively address the challenges in this task and therefore to accurately discriminate the true nodules from a large number of candidates. Methods: We propose a novel method employing three-dimensional (3-D) convolutional neural networks (CNNs) for false positive reduction in automated pulmonary nodule detection from volumetric computed tomography (CT) scans. Compared with its 2-D counterparts, the 3-D CNNs can encode richer spatial information and extract more representative features via their hierarchical architecture trained with 3-D samples. More importantly, we further propose a simple yet effective strategy to encode multilevel contextual information to meet the challenges coming with the large variations and hard mimics of pulmonary nodules. Results: The proposed framework has been extensively validated in the LUNA16 challenge held in conjunction with ISBI 2016, where we achieved the highest competition performance metric (CPM) score in the false positive reduction track. Conclusion: Experimental results demonstrated the importance and effectiveness of integrating multilevel contextual information into 3-D CNN framework for automated pulmonary nodule detection in volumetric CT data. Significance: While our method is tailored for pulmonary nodule detection, the proposed framework is general and can be easily extended to many other 3-D object detection tasks from volumetric medical images, where the targeting objects have large variations and are accompanied by a number of hard mimics.
Autors: Qi Dou;Hao Chen;Lequan Yu;Jing Qin;Pheng-Ann Heng;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jul 2017, volume: 64, issue:7, pages: 1558 - 1567
Publisher: IEEE
 
» Multipactor Breakdown Threshold Reduction Due to Magnetic Confinement in Parallel Fields
Abstract:
In certain high-power RF devices, such as isolators and circulators, a static magnetic field is present in parallel with the oscillating RF electric field. This parallel magnetic field imposes electron Larmor motion, which restricts the trajectories of electrons accelerated by the RF field. In open geometries, magnetic confinement reduces electron losses in the multipactor region and can reduce the breakdown threshold. In this paper, the effect of magnetic confinement on multipactor breakdown threshold was measured experimentally using a stripline fixture with an externally applied uniform magnetic field. Multipactor threshold power was reduced from the unmagnetized case by as much as 3 dB at magnetic fields of about 0.5 kG. Multipactor gap aspect ratio has a significant impact on the degree of threshold reduction.
Autors: Aimee A. Hubble;Vernon H. Chaplin;Kathryn A. Clements;Rostislav Spektor;Preston T. Partridge;Timothy P. Graves;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jul 2017, volume: 45, issue:7, pages: 1726 - 1730
Publisher: IEEE
 
» Multipath Suppression With an Absorber for UWB Wind Turbine Blade Deflection Sensing Systems
Abstract:
The deflection of a wind turbine blade can be monitored with an ultra-wideband (UWB) deflection sensing system, which consists of one transmitting antenna at the blade tip and two receiving antennas at the blade root. The blade deflection is calculated by two estimated tip-root antenna distances. Applying the tip antenna inside a blade is highly preferred in practice, but it leads to strong multipath. The multipath may cause interference and cancellation to the direct pulse and affect the accuracy of tip-root distance estimations. In this paper, a method of utilizing an absorber inside the blade to suppress the multipath is proposed for the in-blade tip antenna. The physical mechanism of the proposed idea is described with a simplified multipath model. Simulations are performed with a 2.5-m-long blade tip section to investigate the tendencies of how the absorber affects pulse waveforms. More accurate verifications of the proposed method are carried out with different full-blade measurements. From all the results, it is found that the proposed technique can efficiently suppress multipath for the in-blade tip antenna, and improve the pulse wave front fidelity, so that the UWB sensing system can also be utilized in a much longer blade. Finally, some other conclusions are also addressed.
Autors: Shuai Zhang;Ondrej Franek;Patrick C. F. Eggers;Claus Byskov;Gert Frølund Pedersen;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2017, volume: 65, issue:7, pages: 2583 - 2595
Publisher: IEEE
 
» Multiple Target Counting and Localization Using Variational Bayesian EM Algorithm in Wireless Sensor Networks
Abstract:
Localization technologies play an increasingly important role in pervasive applications of wireless sensor networks. Since the number of targets is usually limited, localization benefits from compressed sensing (CS): measurements number can be greatly reduced. Despite many CS-based localization schemes, existing solutions implicitly assume that all targets fall on a fixed grid exactly. When the assumption is violated, the mismatch between the assumed and actual sparsifying dictionaries can deteriorate the localization performance significantly. To address such a problem, in this paper, we propose a novel and iterative multiple target counting and localization framework. The key idea behind the framework is to dynamically adjust the grid to alleviate or even eliminate dictionary mismatch. The contribution of this paper is twofold. First, we consider the off-grid target issue in CS-based localization and formulate multiple target counting and localization as a joint sparse signal recovery and parameter estimation problem. Second, we solve the joint optimization problem using a variational Bayesian expectation-maximization algorithm where the sparse signal and parameter are iteratively updated in the variational Bayesian expectation-step and variational Bayesian maximization-step, respectively. Extensive simulation results highlight the superior performance of the proposed framework in terms of probability of correct counting and average localization error.
Autors: Baoming Sun;Yan Guo;Ning Li;Dagang Fang;
Appeared in: IEEE Transactions on Communications
Publication date: Jul 2017, volume: 65, issue:7, pages: 2985 - 2998
Publisher: IEEE
 
» Multiple Trench Split-gate SOI LDMOS Integrated With Schottky Rectifier
Abstract:
In this paper, a multiple trench split-gate silicon-on-insulator (SOI) lateral double-diffused MOSFET with a Schottky rectifier (MTS-SG-LDMOS) is proposed and its characteristics are studied using 2-D simulations. The new structure features double oxide trenches, a floating polysilicon split-gate, and a Schottky rectifier. Each oxide trench includes a vertical field plate which enhances the depletion of the drift region and modulates the bulk electric field. As the simulation results, when compared to the conventional SOI LDMOS (C-LDMOS), the breakdown voltage in the MTS-SG-LDMOS increases from 297 to 350 V, the specific on-state resistance () decreases from 142.9 to 48.2 , and the gate–drain charge () decreases from 19 to 9 pC. Moreover, the reverse recovery time of the proposed structure shows a 73.6% reduction as compared to the C-LDMOS device.
Autors: Ying Wang;Yan-juan Liu;Yi-Fan Wang;Cheng-hao Yu;Fei Cao;Yue Hu;Gaofeng Wang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2017, volume: 64, issue:7, pages: 3028 - 3031
Publisher: IEEE
 
» Multisensor Feature Fusion for Bearing Fault Diagnosis Using Sparse Autoencoder and Deep Belief Network
Abstract:
To assess health conditions of rotating machinery efficiently, multiple accelerometers are mounted on different locations to acquire a variety of possible faults signals. The statistical features are extracted from these signals to identify the running status of a machine. However, the acquired vibration signals are different due to sensor's arrangement and environmental interference, which may lead to different diagnostic results. In order to improve the fault diagnosis reliability, a new multisensor data fusion technique is proposed. First, time-domain and frequency-domain features are extracted from the different sensor signals, and then these features are input into multiple two-layer sparse autoencoder (SAE) neural networks for feature fusion. Finally, fused feature vectors can be regarded as the machine health indicators, and be used to train deep belief network (DBN) for further classification. To verify the effectiveness of the proposed SAE-DBN scheme, the bearing fault experiments were conducted on a bearing test platform, and the vibration data sets under different running speeds were collected for algorithm validation. For comparison, different feature fusion methods were also applied to multisensor fusion in the experiments. Experimental results demonstrated that the proposed approach can effectively identify the machine running conditions and significantly outperform other fusion methods.
Autors: Zhuyun Chen;Weihua Li;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1693 - 1702
Publisher: IEEE
 
» Multistate Multiresonator Spectral Signature Barcodes Implemented by Means of S-Shaped Split Ring Resonators (S-SRRs)
Abstract:
Spectral signature barcodes functional at the frequency band are presented in this paper. The barcodes are implemented by loading a coplanar waveguide transmission line by means of multiple S-shaped split ring resonators (S-SRRs), each one tuned to a different frequency. The main particularity of this paper is the fact that more than two logic states (i.e., three or four, depending on the implementation) are assigned to each resonant element. By this means, the total number of bits of the barcode (for a given number of resonators) is increased, as compared with previous approaches based on two logic states per resonator. This multistate functionality is achieved by rotating the S-SRRs. Such rotation modulates the line-to-resonator coupling intensity, and consequently the notch depth at the S-SRR fundamental resonance. Therefore, by considering three or four fixed rotation angles (or orientations) between the line axis and the S-SRR (for the tri- and four-state multiresonator barcodes, respectively), intermediate levels between the maximum and minimum attenuation are achieved. This multistate strategy only exploits a single frequency per resonant element (the fundamental one). Therefore, the data capacity per bandwidth are improved as compared with two-state-based barcodes or to multistate barcodes that use two frequencies per resonant element. As illustrative examples, two different four-state multiresonator barcodes with eight S-SRRs (providing different codes, or 16 bits) and with nine S-SRRs (equivalent to 18 bits), occupying a spectral bandwidth of 1 GHz and less than 6.75 and 8.2 cm2, respectively, are designed, fabricated, and characterized.
Autors: Cristian Herrojo;Ferran Paredes;Javier Mata-Contreras;Simone Zuffanelli;Ferran Martín;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2017, volume: 65, issue:7, pages: 2341 - 2352
Publisher: IEEE
 
» Multitemporal Landsat Missing Data Recovery Based on Tempo-Spectral Angle Model
Abstract:
Multitemporal Landsat images play an important role in remote sensing applications. Unfortunately, missing data caused by cloud cover and sensor-specific problems have seriously limited its application. To improve the usability of Landsat data, several recovery methods have been proposed to fill the missing values. But, current studies mostly focus on spatial dimension and ignore the continuity of data in time dimension. More importantly, multitemporal images have more potential than single image in selecting similar pixels for recovering the missing pixels. In this paper, to recover missing pixels by jointly utilizing multispectral and multitemporal information, tempo-spectral angle mapping (TSAM) is proposed at first to measure tempo-spectral similarity between pixels described in spectral dimension and temporal dimension. Then, a multitemporal replacement method is used to recover missing data with the pixel selected by TSAM. Two new indices are also proposed to evaluate the effectiveness of TSAM. Simulated and actual multitemporal scan-line corrector-off and cloud cover-Enhanced Thematic Mapper Plus images were used to assess the performance of our filling method. The quantitative evaluations suggest that the proposed method can predict the missing values accurately. The recovered results show that our method can keep the continuity of the boundary and is robust for the data with high percentage of missing.
Autors: Guoming Gao;Yanfeng Gu;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jul 2017, volume: 55, issue:7, pages: 3656 - 3668
Publisher: IEEE
 
» Multiuser Millimeter Wave Communications With Nonorthogonal Beams
Abstract:
Recently, millimeter-wave (mmWave) and even terahertz wireless (with higher frequency) networks have attracted significant research interests as alternatives to support the formidable growth of wireless communication services. Normally, directional beamforming (BF) is shown as a promising technique to compensate its high path loss. We focus on mmWave communications and assume that both mmWave base stations (MBSs) and user equipments (UEs) can support directional BF. As mmWave spectrum has short wavelength, massive antenna arrays can be deployed at MBSs to form multiple directional beams through BF training. Then, an MBS can transmit simultaneously to multiple UEs (SUEs) with different beams in the networks. However, the beams that serve different SUEs may transmit (almost) in the same path, especially when SUEs are distributed densely. Thus, they are not in perfect orthogonal beams. Due to the leakage of transmission power, the interference among these beams may be severe. To address this problem, typically the MBS could serve these SUEs in time division multiplex. This will degrade the spectral efficiency. In this context, we investigate the effect of nonorthogonal beam interference and then propose two novel solutions (i.e., dynamic beam switching and static beam selection) to coordinate the transmitting beams effectively. Then, an improved downlink multiuser simultaneous transmission scheme is introduced. In the scheme, an MBS can serve multiple SUEs simultaneously with multiple orthogonal and/or nonorthogonal beams to guarantee SUEs’ Quality of Service. The theoretical and numerical results have shown that our scheme can largely improve the performance of the achievable rate and, meanwhile, can serve lots of SUEs simultaneously.
Autors: Qing Xue;Xuming Fang;Ming Xiao;Li Yan;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 5675 - 5688
Publisher: IEEE
 
» Multiview Stereoscopic Video Hole Filling Considering Spatiotemporal Consistency and Binocular Symmetry for Synthesized 3D Video
Abstract:
This paper proposes a new hole-filling method with spatiotemporal consistency and binocular symmetry for synthesized 3D videos in view extrapolation. Disocclusion regions in the synthesized views at virtual viewpoints result in regions with missing content. These regions will be referred to as hole regions. To provide the high-quality synthesized 3D videos via 3D display, the hole regions need to be filled considering the characteristics of human visual perception. From the perceptual point of view, binocular asymmetry between synthesized left- and right-eye videos (i.e., stereo pair video) is one of the most important factors that induce visual discomfort in stereoscopic viewing. In addition, binocular symmetry without temporal consistency between temporally neighboring frames could cause visual discomfort by annoying flickering artifacts. In this paper, to maintain the spatiotemporal consistency and binocular symmetry in synthesized 3D videos at multiple virtual viewpoints, we propose a global optimization-based hole-filling method using the information from the already filled adjacent view and previous frame. Furthermore, to reduce the computational cost of the global optimization, we propose a label propagation method, which propagates reliable labels used in the adjacent view and previous frame to the target image to be filled. The performance of the proposed method has been evaluated by objective assessments of 3D image quality, temporal consistency, and computational efficiency. In addition, subjective assessment is conducted for measuring the visual comfort and overall quality. The experimental results proved that the proposed method provides hole filling results with spatiotemporal consistency and binocular symmetry.
Autors: Hak Gu Kim;Yong Man Ro;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jul 2017, volume: 27, issue:7, pages: 1435 - 1449
Publisher: IEEE
 
» Muscle Activity Map Reconstruction from High Density Surface EMG Signals With Missing Channels Using Image Inpainting and Surface Reconstruction Methods
Abstract:
Objective: The aim of this study was to reconstruct low-quality High-density surface EMG (HDsEMG) signals, recorded with 2-D electrode arrays, using image inpainting and surface reconstruction methods. Methods: It is common that some fraction of the electrodes may provide low-quality signals. We used variety of image inpainting methods, based on partial differential equations (PDEs), and surface reconstruction methods to reconstruct the time-averaged or instantaneous muscle activity maps of those outlier channels. Two novel reconstruction algorithms were also proposed. HDsEMG signals were recorded from the biceps femoris and brachial biceps muscles during low-to-moderate-level isometric contractions, and some of the channels (5–25%) were randomly marked as outliers. The root-mean-square error (RMSE) between the original and reconstructed maps was then calculated. Results: Overall, the proposed Poisson and wave PDE outperformed the other methods (average RMSE and ) for the time-averaged single-differential and monopolar map reconstruction, respectively. Biharmonic Spline, the discrete cosine transform, and the Poisson PDE outperformed the other methods for the instantaneous map reconstruction. The running time of the proposed Poisson and wave PDE methods, implemented using a Vectorization package, was and , respectively, for each si- nal epoch or time sample in each channel. Conclusion: The proposed reconstruction algorithms could be promising new tools for reconstructing muscle activity maps in real-time applications. Significance: Proper reconstruction methods could recover the information of low-quality recorded channels in HDsEMG signals.
Autors: Parviz Ghaderi;Hamid R. Marateb;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jul 2017, volume: 64, issue:7, pages: 1513 - 1523
Publisher: IEEE
 
» Narrow-Band Interference Mitigation Using Compressive Sensing for AF-OFDM Systems
Abstract:
We investigate narrow-band-interference (NBI) mitigation for single and multiple relay amplify-and-forward (AF) orthogonal-frequency-division-multiplexing (OFDM) cooperative communication systems. Based on the channel gains between the interferer, destination, and relay nodes, three copies or more of the NBI signal are received at the destination node, in addition to the desired signal. NBI degrades the performance of AF-OFDM systems, which motivates the need for NBI mitigation techniques. NBI is a sparse signal in the frequency-domain (FD); hence, a compressive sensing framework can be used to estimate NBI and cancel it before detecting the transmitted signal. However, frequency-grid-mismatch destroys the sparsity of NBI in the FD at the receiver. Therefore, we propose a structured-dictionary-mismatch formulation to estimate the frequency-grid-mismatch and recover NBI in the FD. While convex optimization techniques can be used to recover NBI, their computational complexity is high. Therefore, we apply a block-orthogonal-matching-pursuit greedy algorithm to reduce the computational complexity of NBI recovery, where the sensing matrix is rearranged to have sparse blocks. Simulation results demonstrate the advantages of our proposed approach.
Autors: Hanan Al-Tous;Imad Barhumi;Naofal Al-Dhahir;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2017, volume: 66, issue:7, pages: 6146 - 6159
Publisher: IEEE
 
» Necessary and Sufficient Conditions on the Exponential Stability of Positive Hyperbolic Systems
Abstract:
In this paper, a strict linear Lyapunov function is developed in order to investigate the exponential stability of a linear hyperbolic partial differential equation with positive boundary conditions. Based on the method of characteristics, some properties of the positive solutions are derived for the hyperbolic initial boundary value problems. The dissipative boundary condition in terms of linear inequalities is proven to be not only sufficient but also necessary under an extra assumption on the velocities of the hyperbolic systems. An application to control of the freeway traffic modeled by the Aw–Rascle traffic flow equation illustrates and motivates the theoretical results. The boundary control strategies are designed by integrating the on-ramp metering with the mainline speed limit. Finally, the proposed feedback laws are tested under simulation, first in the free-flow case and then in the congestion mode, which show adequate performance to stabilize the local freeway traffic.
Autors: Liguo Zhang;Christophe Prieur;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3610 - 3617
Publisher: IEEE
 
» Neighbor Discovery and Rendezvous Maintenance with Extended Quorum Systems for Mobile Applications
Abstract:
In many mobile sensing applications, devices need to discover new neighbors and maintain the rendezvous with known neighbors continuously. Due to the limited energy supply, these devices have to duty cycle their radios to conserve the energy and bandwidth, making neighbor discovery and rendezvous maintenance even more challenging. To date, the main mechanism for device discover and rendezvous maintenance in existing solutions is pairwise, direct one-hop communication. We argue that such pairwise direct communication is sufficient but not necessary: there exist unnecessary active slots that can be eliminated, without affecting discovery and rendezvous. In this work, we propose a novel concept of extended quorum system, which leverages indirect discovery to further conserve energy. Specifically, we use quorum graph to capture all possible information flow paths where knowledge about known-neighbors can propagate among devices. By eliminating redundant paths, we can reduce the number of active slots significantly. Since a quorum graph can characterize arbitrary active schedules of mobile devices, our work can be broadly used to improve many existing quorum-based discovery and rendezvous solutions. We comprehensively evaluate in three different scales of networks, and the results show that reduces as much as 55 percent energy consumption with a maximal 5 percent increase in latency for existing solutions. To test the real-world values of , we furthe- propose a taxicab dispatching application called -dispatch to navigate taxicab drivers to the area with less competition based on the discovery results of nearby taxicabs.
Autors: Desheng Zhang;Tian He;Fan Ye;Raghu K. Ganti;Hui Lei;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jul 2017, volume: 16, issue:7, pages: 1967 - 1980
Publisher: IEEE
 
» Networked Microgrids for Enhancing the Power System Resilience
Abstract:
This paper focuses on the role of networked microgrids as distributed systems for enhancing the power system resilience against extreme events. Resilience is an intrinsically complex property which requires deep understanding of microgrid operation in order to respond effectively in emergency conditions. The paper first introduces the definition and offers a generic framework for analyzing the power system resilience. The notion that large power systems can achieve a higher level of resilience through the deployment of networked microgrids is discussed in detail. In particular, the management of networked microgrids for riding through extreme events is analyzed. In addition, the merits of advanced information and communication technologies (ICTs) in microgrid-based distributed systems that can support the power system resilience are presented. The paper also points out the challenges for expanding the role of distributed systems and concludes that networked microgrids in particular provide a universal solution for improving the resilience against extreme events in Smart Cities.
Autors: Zhiyi Li;Mohammad Shahidehpour;Farrokh Aminifar;Ahmed Alabdulwahab;Yusuf Al-Turki;
Appeared in: Proceedings of the IEEE
Publication date: Jul 2017, volume: 105, issue:7, pages: 1289 - 1310
Publisher: IEEE
 
» Networked Microgrids: Exploring the Possibilities of the IIT-Bronzeville Grid
Abstract:
Bronzeville is a community located in the city of Chicago that features a diverse historic district with essential city services, residential housing, and educational institutions. The Bronzeville neighborhood houses the headquarters of the Chicago Police and Fire Department, De La Salle Institute, Illinois College of Optometry, Boulevard Care Center, Chicago Public Library, Pilgrim Baptist Church, Bronzeville Nursing and Living Center, Chicago Military Academy, Pentecostal Church, Perspectives Math & Science Academy, and other institutions. The area provides an ideal location for the continued refinement and development of advanced electric power services, which can be demonstrated through the implementation of a community microgrid: the Bronzeville community microgrid (BCM). The BCM is the backbone of a planned community of the future, where residents and critical facilities enjoy a sustainable environment and utilize innovative smart grid products. The BCM can serve as a pilot project for demonstrating the merits of instituting Chicago as a smart city. Distribution automation devices capable of fault interruption and sectionalization will be strategically deployed so that a fault would only result in a local outage rather than an interruption to the entire area. The BCM operation will comprise several types of distributed energy resources (DER s). A battery energy storage system (BESS) located in close proximity to photovoltaic panels provides an effective means to mitigate the variability of renewable energy. The BESS is also effective in improving the power quality at customer sites.
Autors: Mohammad Shahidehpour;Zhiyi Li;Shay Bahramirad;Zuyi Li;Wei Tian;
Appeared in: IEEE Power and Energy Magazine
Publication date: Jul 2017, volume: 15, issue:4, pages: 63 - 71
Publisher: IEEE
 
» Neural nets vs. lego bricks [Resources]
Abstract:
For many years as a child, I did nothing but play with Lego. Eventually I had children of my own, who had a nice Lego collection themselves, but nothing you’d need machinery to sort. That changed after a trip to Legoland in Denmark.
Autors: Jacques Mattheij;
Appeared in: IEEE Spectrum
Publication date: Jul 2017, volume: 54, issue:7, pages: 17 - 18
Publisher: IEEE
 
» New Associate Editor
Abstract:
It is with pleasure that I welcome two new Associate Editors to the editorial board of the IEEE Journal of Solid-State Circuits (JSSC). David Stoppa brings his expertise in biosensors and image sensors, topics which are of much interest in the IEEE JSSC. Jeffrey Gealow has a broad background in mixed-signal circuits, and is specifically recognized for his expertise in analog-to-digital converters. I wish both of them good luck with their new task.
Autors: Jan Craninckx;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2017, volume: 52, issue:7, pages: 1699 - 1699
Publisher: IEEE
 
» New Criteria on $p$th Moment Input-to-State Stability of Impulsive Stochastic Delayed Differential Systems
Abstract:
By employing the Razumikhin technique, the uniformly exponentially stable function and the average dwell-time (ADT) approach, some Razumikhin-type theorems on input-to-state stability (ISS) for time-varying impulsive stochastic delay differential systems (ISDDS) are obtained. It is shown that if the time-varying continuous stochastic delayed dynamics is ISS and the impulsive effects are destabilizing, then the ISDDS is input-to-state stable (ISS) with respect to a lower bound of the average dwell-time (ADT). The existing results on ISS of impulsive systems in the literature require the coefficients of the estimated upper bound for the diffusion operator of a Lyapunov function to be constant numbers. While, the results in this note allow us the coefficients of the estimated upper bound of the diffusion operator to be sign-changing time-varying function. An example is given to illustrate the effectiveness of our results. From the example, one can see the existing results fail to be used to determine the ISS for some type of ISDDS.
Autors: Shiguo Peng;Feiqi Deng;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3573 - 3579
Publisher: IEEE
 
» New MPEG-7 Scalable Color Descriptor Based on Polar Coordinates for Multispectral Earth Observation Image Analysis
Abstract:
Continuously expanding high-resolution and very high resolution multispectral image collections, provided by remote sensing satellites, require specific methods and techniques for data analysis and understanding. Even though there are several patch-based approaches for image classification and indexing, none of them are integrated within a standard. Having the goal to develop an MPEG-7 compliant descriptor for patch-based multispectral earth observation image classification and indexing, we propose a new feature extraction method able to extract maximum information from all the available spectral bands that Sentinel 2, the last generation of remote sensing satellites, provides. Using the polar coordinate transformation of the reflectance values, we obtain illumination invariant features, which can be used along with the scalable color descriptor present in MPEG-7 standard. Also, our method proves to enhance land cover classification of the areas affected by clouds and their shadows and provide similar classification results compared with the homogeneous texture descriptor (HTD), spectral histogram (SH), concatenated HTD with SH features, spectral indices (SIs), and bag-of-words-based descriptors, such as bag-of-SIs and bag-of-spectral-values on cloud-free areas.
Autors: Florin-Andrei Georgescu;Dan Răducanu;Mihai Datcu;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jul 2017, volume: 14, issue:7, pages: 987 - 991
Publisher: IEEE
 
» New Perspectives on Droop Control in AC Microgrid
Abstract:
Virtual impedance, angle droop, and frequency droop control play important roles in maintaining system stability, and load sharing among distributed generators (DGs) in microgrid. These approaches have been developed into three totally independent concepts, but a strong correlation exists. In this letter, their similarities and differences are revealed. Some new findings are established as follows: 1) the angle droop control is intrinsically a virtual inductance method; 2) virtual inductance method can also be regarded as a special frequency droop control with a power derivative feedback; and 3) the combination of virtual inductance method and frequency droop control is equivalent to the proportional–derivative type frequency droop, which is introduced to enhance the power oscillation damping. These relationships provide new insights into the design of the control methods for DGs in microgrid.
Autors: Yao Sun;Xiaochao Hou;Jian Yang;Hua Han;Mei Su;Josep M. Guerrero;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5741 - 5745
Publisher: IEEE
 
» New Results on Stability of Slowly Switched Systems: A Multiple Discontinuous Lyapunov Function Approach
Abstract:
In this technical note, the problem of stability for a class of slowly switched systems is investigated. By developing a novel multiple discontinuous Lyapunov function approach and exploring the feature of mode-dependent dwell time switching, new stability conditions are established for systems with a designed switching strategy where fast switching and slow switching are respectively applied to unstable and stable subsystems. In particular, stability conditions for linear switched systems are also given via choosing multiple discontinuous Lyapunov functions in the quadratic form. Moreover, stability criteria for the systems consisting of stable subsystems are also derived. It is shown that our proposed results cover some existing ones in literature as special cases, and provide tighter bounds on the dwell time. Finally, some simulation results are provided to show the advantages of the theoretic results obtained.
Autors: Xudong Zhao;Peng Shi;Yunfei Yin;Sing Kiong Nguang;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2017, volume: 62, issue:7, pages: 3502 - 3509
Publisher: IEEE
 
» New Vector Single-Source Surface Integral Equation for Scattering Problems on Dielectric Objects in 2-D
Abstract:
A new surface single-source integral equation (SSIE) is proposed for the solution of electromagnetic wave scattering problems in two dimensions. The traditional volume electric field integral equation (V-EFIE) is reduced to the new single-source surface integral equation by representing the electric field inside the scatterer as a superposition of cylindrical waves emanating from its boundary. While being rigorous in nature, the new single-source surface integral equation features half of the degrees of freedom compared with traditional surface integral equation formulations. It is amenable to derivative-free method of moments discretization as it features only electric-field-type of Green’s function instead of both electric and magnetic field Green’s functions.
Autors: Farhad Sheikh Hosseini Lori;Anton Menshov;Vladimir I. Okhmatovski;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2017, volume: 65, issue:7, pages: 3794 - 3799
Publisher: IEEE
 
» NIC: A Robust Background Extraction Algorithm for Foreground Detection in Dynamic Scenes
Abstract:
This paper presents a robust foreground detection method capable of adapting to different motion speeds in scenes. A key contribution of this paper is the background estimation using a proposed novel algorithm, neighbor-based intensity correction (NIC), that identifies and modifies the motion pixels from the difference of the background and the current frame. Concretely, the first frame is considered as an initial background that is updated with the pixel intensity from each new frame based on the examination of neighborhood pixels. These pixels are formed into windows generated from the background and the current frame to identify whether a pixel belongs to the background or the current frame. The intensity modification procedure is based on the comparison of the standard deviation values calculated from two pixel windows. The robustness of the current background is further measured using pixel steadiness as an additional condition for the updating process. Finally, the foreground is detected by the background subtraction scheme with an optimal threshold calculated by the Otsu method. This method is benchmarked on several well-known data sets in the object detection and tracking domain, such as CAVIAR 2004, AVSS 2007, PETS 2009, PETS 2014, and CDNET 2014. We also compare the accuracy of the proposed method with other state-of-the-art methods via standard quantitative metrics under different parameter configurations. In the experiments, NIC approach outperforms several advanced methods on depressing the detected foreground confusions due to light artifact, illumination change, and camera jitter in dynamic scenes.
Autors: Thien Huynh-The;Oresti Banos;Sungyoung Lee;Byeong Ho Kang;Eun-Soo Kim;Thuong Le-Tien;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jul 2017, volume: 27, issue:7, pages: 1478 - 1490
Publisher: IEEE
 
» Nitrogen Dioxide Gas Sensor Based on Monolayer SnS: A First-Principle Study
Abstract:
The sensing behavior of monolayer tin sulfide (SnS) for four gas molecules (NH3, NO2, CO, and H2O) are studied by the first-principle calculation based on density-functional theory. We calculate adsorption energy, adsorption distance, and Hirshfeld charge to estimate the adsorption ability of monolayer SnS for these gas molecules. The results demonstrate that all the gas molecules show physisorption nature. We further calculate the current–voltage (–) curves using the nonequilibrium Green’s function formalism for evaluating the NO2 gas sensing properties. The monolayer SnS is found to be strongly sensitive to NO2 molecule dependent on moderate adsorption energy, excellent charge transfer, and significant change of – property before and after gas adsorption. Therefore, we suggest that monolayer SnS can be a prominent candidate for application as NO2 gas sensor.
Autors: Fa-Fei Hu;Hong-Yu Tang;Chun-Jian Tan;Huai-Yu Ye;Xian-Ping Chen;Guo-Qi Zhang;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2017, volume: 38, issue:7, pages: 983 - 986
Publisher: IEEE
 
» No-Load Magnetic Field and Cogging Force Calculation in Linear Permanent-Magnet Synchronous Machines With Semiclosed Slots
Abstract:
This paper presents an improved analytical subdomain model for predicting the magnetic field in linear permanent magnet synchronous machines (LPMSMs) with semiclosed slots accounting for the finite length of primary iron core and secondary back-iron. The whole field domain is divided into eight subdomains and the magnetic field in each subdomain is solved by applying the variable separation method, adequate boundary conditions, and interface conditions. In this model, both the slot and end effects are considered. The thrust and normal forces are calculated by the Maxwell stress theory. The finite element analysis is carried out to validate the analytical model. Finally, an LPMSM prototype is manufactured and tested. The experimental results show that the developed analytical model has high accuracy for predicting the magnetic field and forces.
Autors: Hengzai Hu;Jing Zhao;Xiangdong Liu;Youguang Guo;Jianguo Zhu;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jul 2017, volume: 64, issue:7, pages: 5564 - 5575
Publisher: IEEE
 
» Node Positioning and Lifetime Optimization for Wireless Body Area Networks
Abstract:
Wireless communication networks may be categorized based on the extent of the geographical area that they cover. The latest trend in this assortment is wireless body area network (WBAN), which is standardized by IEEE 802.15.6 and is defined as a network composed of intelligent, miniaturized, low-power nodes that are implanted in, placed on, or in close proximity to the human body for certain healthcare applications. In this paper, we will start with some assessments on applicable channel models for a typical WBAN. Considering various scenarios with different carrier frequencies, bandwidths, body movements, and transceiver locations, the well-known Bayesian Information Criterion is used to check an available channel data set against 11 different statistical models. Having the channel models as the tools of the trade, we have chosen symbol error rate as the desired metric to find the best node location among the predefined options that results in the most reliable performance. Apart from the positioning of individual nodes, the reliability concept can be utilized in the context of a more general problem, giving rise to useful applications beyond a single node level. Here, we introduce the network lifetime as the performance indicator that can be evaluated for any scenario of interest. Moreover, the network lifetime may be treated as the cost function of an optimization problem. By following the requirements mentioned in the standard, we have found the optimum values for different node attributes that result in the network lifetime maximization.
Autors: Ali Razavi;Mehran Jahed;
Appeared in: IEEE Sensors Journal
Publication date: Jul 2017, volume: 17, issue:14, pages: 4647 - 4660
Publisher: IEEE
 
» Non-Linear Distortion Cancellation and Symbol-Based Equalization in Satellite Forward Links
Abstract:
In this paper, a low-complexity symbol-based equalizer that performs non-linear distortion cancellation is proposed for application at the user terminal in the DVB-S2X satellite forward link. The channel is comprehensively modeled, including the non-linear travelling wave tube amplifier characteristics, the input-multiplexing and output-multiplexing filter responses at the satellite transponder, and the phase noise at the user terminal, according to the very-small aperture terminal reference scenario. Two detectors in the cancellation loop are considered, comparing the packet-error rate (PER) performance of simple maximum likelihood demodulation with hard decision to soft information exchange with low-density parity-check decoder, and showing only marginal improvement with the latter solution. The PER performance is compared against a number of pre-distortion techniques at the transmitter, such as dynamic data pre-distortion, successive data pre-distortion, and static data pre-distortion. The novel receiver demonstrates superior performance even with one iteration of distortion cancellation, while the joint application of successive data pre-distortion and iterative symbol-based equalization shows up to 4.95-dB energy efficiency gain for 32-level amplitude and phase-shift keying (32-APSK). The computational complexity is also evaluated. The improved receiver is particularly suitable for application with higher order modulation, a wide-band carrier, and low roll-off factors.
Autors: Svilen Dimitrov;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jul 2017, volume: 16, issue:7, pages: 4489 - 4502
Publisher: IEEE
 
» Non-Orthogonal Random Access for 5G Networks
Abstract:
The massive amounts of machine-type user equipments (UEs) will be supported in the future fifth generation (5G) networks. However, the potential large random access (RA) delay calls for a new RA scheme and for a detailed assessment of its performance. Motivated by the key idea of non-orthogonal multiple access, the non-orthogonal RA (NORA) scheme based on successive interference cancellation (SIC) is proposed in this paper to alleviate the access congestion problem. Specifically, NORA utilizes the difference of time of arrival to identify multiple UEs with the identical preamble, and enables power domain multiplexing of collided UEs in the following access process, while the base station performs SIC based on the channel conditions obtained through preamble detection. Our analysis shows that the performance of the NORA is superior to the conventional orthogonal RA (ORA) scheme in terms of the preamble collision probability, access success probability, and the throughput of RA. Simulation results verify our analysis and further show that our NORA scheme can improve the number of the supported UEs by more than 30%. Moreover, the number of preamble transmissions and the access delay for successfully accessed UEs are also reduced significantly by using the proposed RA scheme.
Autors: Yanan Liang;Xu Li;Jiayi Zhang;Zhiguo Ding;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jul 2017, volume: 16, issue:7, pages: 4817 - 4831
Publisher: IEEE
 
» Noncontact Physiological Dynamics Detection Using Low-power Digital-IF Doppler Radar
Abstract:
The instantaneous vital sign rates, which are related to physiological dynamics, are important indicators of human health condition. This paper presents a noncontact way to measure the human instantaneous vital signs using digital-intermediate frequency (IF) Doppler radar. The synchrosqueezing transform-based algorithm has been proposed to get a concentrated time-frequency (TF) distribution, so that the high-resolution instantaneous heartbeat and respiratory rates and the time-domain signals can be acquired. Moreover, the developed radar with customized radio frequency module employs the direct IF sampling technique to achieve high sensitivity to capture the tiny vital sign variations. Experiments with different human subjects and physiological conditions have been carried out. Compared with the landmark-based method and traditional TF algorithms, the results show that instantaneous vital signs can be acquired more accurately within 3 m at a -13 dBm transmit power by the proposed method. Therefore, the radar can be used for evaluating the physiological dynamics and assessing health condition.
Autors: Heng Zhao;Hong Hong;Li Sun;Yusheng Li;Changzhi Li;Xiaohua Zhu;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2017, volume: 66, issue:7, pages: 1780 - 1788
Publisher: IEEE
 
» Noninvasive Material Thickness Detection by Aerosol Jet Printed Sensors Enhanced Through Metallic Carbon Nanotube Ink
Abstract:
Demand for cheaper and more functional sensors continues to rise in an era when data can be used to improve health, safety, and efficiency in daily lives. In this paper, we present a fully printed sensor capable of noninvasive material thickness detection. By applying an oscillating signal between two millimeter-scale electrodes, the fringing electric field is measurably perturbed by a material placed directly on top of the electrodes, leading to a linearly varying capacitance with change in the material’s thickness. We simulate this electric field perturbation and experimentally demonstrate the linear correlation between capacitance and overlying material thickness. Various parameters, from sensor size and structure to substrate and ink materials, are studied to optimize the performance of the printed sensors. Sensors made of metallic carbon nano-tube ink yield the best sensitivity, exhibiting a capacitance change of 26 fF per mm thickness of rubber—ten times more sensitive than devices composed of silver nanoparticle ink. Finally, we demonstrate an effective application of the sensors in automobile tires. By applying the sensors directly beneath the tread (within the tire), mm changes in the tread depth are able to be detected in a 99% confidence interval. These findings provide a straightforward, low-cost approach for monitoring mm changes in material thickness using noninvasive, printed sensors applicable to innumerable Internet-of-Things (IoT) applications.
Autors: Joseph B. Andrews;Changyong Cao;Martin A. Brooke;Aaron D. Franklin;
Appeared in: IEEE Sensors Journal
Publication date: Jul 2017, volume: 17, issue:14, pages: 4612 - 4618
Publisher: IEEE
 
» Nonlinear Analytical Prediction of Magnetic Field and Electromagnetic Performances in Switched Reluctance Machines
Abstract:
This paper deals with the nonlinear analytical harmonic modeling (HM) of three phases, and 6/4 conventional switched reluctance machine (SRM). The proposed model consists in computing magnetic field distribution and electromagnetic performances of an SRM with conventional winding. Because an SRM has inherently nonlinear characteristics, the analytical subdomain model that does not take into account the saturation has a limited accuracy. This is due to the assumption of infinite tooth permeability. The new analytical model (AM) based on the HM technique, which overcomes this limitation, is presented with the consideration of the local magnetic saturation on the stator and rotor teeth. The results obtained with the nonlinear AM have been compared with the linear AM based on the subdomain method (i.e., without the saturation effect) and nonlinear finite-element method solutions.
Autors: Zakarya Djelloul-Khedda;Kamel Boughrara;Frédéric Dubas;Rachid Ibtiouen;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jul 2017, volume: 53, issue:7, pages: 1 - 11
Publisher: IEEE
 
» Nonlinear Model Suitable for the Offline Cosimulation of Fault-Tolerant PM Motors Drives
Abstract:
This paper presents a dynamic model suitable for accurate cosimulation of fault-tolerant permanent-magnet motor drives featuring independent-phase structure. The model is developed in a circuital form where the usual inductive parameters and back electromotive force coefficient are replaced by current and rotor position dependent functions, so that the exact electromagnetic nature and geometry of the machine are accounted over the large flux-current operating range. The model functions are precomputed by a finite element method analysis of a single phase of the machine, once the magnetic independence among the phases has been verified. Then, the circuital model is solved by a dynamical simulator which implements also the drive system, converter, and control, following on the offline cosimulation approach. The proposed model is validated by experiments carried on a fault-tolerant five-phase permanent-magnet motor-drive for aeronautical application, controlled by the brushless dc technique. The results show that the modeling solution is capable to simulate the motor dynamics with a high degree of accuracy, and can be used for an effective rapid prototyping of fault-tolerant drives.
Autors: Marco Tursini;Marco Villani;Alessio Di Tullio;Giuseppe Fabri;Francesco Parasiliti Collazzo;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2017, volume: 53, issue:4, pages: 3719 - 3729
Publisher: IEEE
 
» Nonnegative Discriminant Matrix Factorization
Abstract:
Nonnegative matrix factorization (NMF), which aims at obtaining the nonnegative low-dimensional representation of data, has received wide attention. To obtain more effective nonnegative discriminant bases from the original NMF, in this paper, a novel method called nonnegative discriminant matrix factorization (NDMF) is proposed for image classification. NDMF integrates the nonnegative constraint, orthogonality, and discriminant information in the objective function. NDMF considers the incoherent information of both factors in standard NMF and is proposed to enhance the discriminant ability of the learned base matrix. NDMF projects the low-dimensional representation of the subspace of the base matrix to regularize the NMF for discriminant subspace learning. Based on the Euclidean distance metric and the generalized Kullback–Leibler (KL) divergence, two kinds of iterative algorithms are presented to solve the optimization problem. The between- and within-class scatter matrices are divided into positive and negative parts for the update rules and the proofs of the convergence are also presented. Extensive experimental results demonstrate the effectiveness of the proposed method in comparison with the state-of-the-art discriminant NMF algorithms.
Autors: Yuwu Lu;Zhihui Lai;Yong Xu;Xuelong Li;David Zhang;Chun Yuan;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jul 2017, volume: 27, issue:7, pages: 1392 - 1405
Publisher: IEEE
 

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