Electrical and Electronics Engineering publications abstract of: 01-2017 sorted by title, page: 11

» Monitoring Ground Subsidence Along the Shanghai Maglev Zone Using TerraSAR-X Images
Abstract:
In this letter, the permanent scatterer interferometric synthetic aperture radar (PS-InSAR) method is applied to extract ground subsidence using X-band TerraSAR-X images. A zone of 1 km width on both sides of the Shanghai maglev was selected, and the ground subsidence rates were obtained on all permanent scatters or highly coherent targets. The results show that permanent scatters are distributed on the rail of the maglev, and the subsidence rates of these PS points are mostly less than 3 mm/a. A KS-test is formulated to judge the agreements between the subsidence results obtained by PS-InSAR and those obtained by spirit leveling, which indicated that PS-InSAR results are acceptable statistically. In addition, the PS-InSAR results show some ground subsiding troughs near the maglev track, with subsidence rates of more than 10 mm/a.
Autors: Jicang Wu;Fengming Hu;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jan 2017, volume: 14, issue:1, pages: 117 - 121
Publisher: IEEE
 
» Monitoring the Shape of Satellite Wing Frame Using FBG Sensors in High Electronic Noise, Vacuum, and −196 °C Environment
Abstract:
In a normal environment on Earth, there are several methods for obtaining the deflection curve of a satellite wing frame, such as the laser method and the electronic resistance strain gauge method. However, none of them are suitable for the outer space environment. Therefore, developing a reliable sensing solution for a high electronic noise, vacuum, and extremely low-temperature environment may be a very challenging task. In this paper, a new fiber Bragg grating (FBG) sensors method is proposed to meet this harsh environment need. First, hundreds of FBG sensors are pasted onto the surface of a satellite wing frame to detect the strain data. Second, the cubic spline interpolation function, quadratic integral function, and quantic polynomial function are used for the data processing to obtain the shape of the satellite wing frame. Finally, a satellite wing frame is placed in a heat sink to conduct a shape monitoring experiment. Furthermore, a verification experiment in a normal environment shows the reliability of the FBG sensors method. Because the FBG sensors and the supporting equipment are available in the market, this method is a feasible solution for shape monitoring in outer space.
Autors: Peng Wei;Jie Liu;Zejing Dai;Ming Li;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 691 - 700
Publisher: IEEE
 
» Monocular Visual–Inertial State Estimation With Online Initialization and Camera–IMU Extrinsic Calibration
Abstract:
There have been increasing demands for developing microaerial vehicles with vision-based autonomy for search and rescue missions in complex environments. In particular, the monocular visual–inertial system (VINS), which consists of only an inertial measurement unit (IMU) and a camera, forms a great lightweight sensor suite due to its low weight and small footprint. In this paper, we address two challenges for rapid deployment of monocular VINS: 1) the initialization problem and 2) the calibration problem. We propose a methodology that is able to initialize velocity, gravity, visual scale, and camera–IMU extrinsic calibration on the fly. Our approach operates in natural environments and does not use any artificial markers. It also does not require any prior knowledge about the mechanical configuration of the system. It is a significant step toward plug-and-play and highly customizable visual navigation for mobile robots. We show through online experiments that our method leads to accurate calibration of camera–IMU transformation, with errors less than 0.02 m in translation and 1° in rotation. We compare out method with a state-of-the-art marker-based offline calibration method and show superior results. We also demonstrate the performance of the proposed approach in large-scale indoor and outdoor experiments.
Autors: Zhenfei Yang;Shaojie Shen;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2017, volume: 14, issue:1, pages: 39 - 51
Publisher: IEEE
 
» Moore's law's next step: 10 nanometers
Abstract:
These days, forecasts about the future of Moore’s Law tend to look quite gloomy. But Intel’s outlook—at least for the next few years—is decidedly bright.
Autors: Rachel Courtland;
Appeared in: IEEE Spectrum
Publication date: Jan 2017, volume: 54, issue:1, pages: 52 - 53
Publisher: IEEE
 
» Motion Detection and Compensation of Affine Deformations in Infrared Retinal Videos
Abstract:
Diabetic macular edema (DME) affects the retina and reduces the visual acuity of patients with severe diabetic retinopathy. Its conventional treatment involves laser photocoagulation combined with infrared (IR) imaging. However, the laser beam may hit healthy retinal areas and cause unintentional retinal damages if retinal motion occurs. We propose a method for retinal motion detection and compensation that relies on phase correlations in the image and in the log-polar domains, and is robust to affine retinal deformations (e.g., rotations, scales, and translations) in IR videos. The proposed method is also robust to the background noise and illumination changes commonly occurring in this retinal imaging modality. The proposed method can be used to estimate the retinal affine motion parameters and compensate for small retinal motions (nearly 50 ). The critical method parameters are selected and adjusted optimally, which improves the robustness of the method. The experimental results suggest that the proposed method potentially can be more robust for detecting retinal motion and for estimating the parameters of affine retinal deformations than comparable methods that currently represent the state of the art, which helps to improve the reliability of laser treatments for DME.
Autors: Lucas Royes Schardosim;Jacob Scharcanski;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2017, volume: 66, issue:1, pages: 33 - 44
Publisher: IEEE
 
» Motion-planning chip speeds robots
Abstract:
If you've seen a robot manipulation demo, you’ve almost certainly noticed that the robot tends to spend a lot of time looking like it’s not doing anything. It’s tempting to say that the robot is “thinking” when this happens, and that might even be mostly correct: Odds are that you’re waiting for some motionplanning algorithm to figure out how to get the robot’s arm and gripper to do what it’s supposed to do without running into anything. This motion-planning process is one of the most important skills a robot can have, and it’s also one of the most time consuming.
Autors: Evan Ackerman;
Appeared in: IEEE Spectrum
Publication date: Jan 2017, volume: 54, issue:1, pages: 9 - 10
Publisher: IEEE
 
» Motor and Drive-System Efficiency Regulations: Review of Regulations in the United States and Europe
Abstract:
The U.S. Department of Energy (DOE ) issu ed new efficiency regulations in May 2014 [1] for integral horsepower motors effective June 2016. This article will provide an update on these new regulations for 1-500-hp low-voltage (LV) ac induction motors. The scope of coverage has been expanded to cover more configurations than in previous regulations. National Electrical Manufacturers Association (NEMA ) 56 frame-enclosed motors are covered. Motor regulations for Canada and Mexico generally follow what is adopted in the United States. Europe is updating succeeding regulations for LV motors (<1,000 V) and drive systems with an extended product approach from 0.12 to 1,000 kW by 2018. The DOE is also studying pump, fan, and compressor systems and how their efficiency can be regulated. We will provide an overview of the DOE proposals and the new European standard for efficient drive systems if any users wish to follow and become involved with comments. This article will review the motor and system efficiency regulations issued by the DOE and discuss extended product regulations under development by the European Union (EU).
Autors: John Malinowski;William Hoyt;Peter Zwanziger;Bill Finley;
Appeared in: IEEE Industry Applications Magazine
Publication date: Jan 2017, volume: 23, issue:1, pages: 34 - 41
Publisher: IEEE
 
» Motor Bus Transfer System Performance Testing and the Search for a New Transfer Success Criterion
Abstract:
The petrochemical industry presently has no industry standards on the performance requirements for relays used to supervise critical process motor bus transfers (MBTs). A device testing protocol is proposed, and the results of extensive performance testing of relays used to implement the fast and in-phase methods of a motor bus synchronous transfer are analyzed. The existing industry criteria for determining the success of a completed transfer are used to evaluate these test results. The development of digital MBT systems with data recording capabilities provided a means of recording transfer data and provides key insight into what happens during actual transfers. Case studies of a number of live MBTs are presented and analyzed to begin to determine if a new transfer metric can be derived, based on recorded transfer inrush current and power when transfer is completed.
Autors: Thomas R. Beckwith;Charles J. Mozina;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 653 - 659
Publisher: IEEE
 
» MUBFP: Multiuser Beamforming and Partitioning for Sum Capacity Maximization in MIMO Systems
Abstract:
The multiuser beamforming (MUBF) scheme has attracted tremendous attention as a suboptimal linear precoding technique to realize the benefits of system capacity in multiple-input–multiple-output (MIMO) systems. Due to mutual interference between cochannel users, the objective of maximizing the system capacity and fair service provisioning to different users should be well balanced in the design of the MUBF scheme. To this end, we propose a framework for the joint multiuser beamforming and partitioning (MUBFP) design problem, which attempts to partition users into a set of disjoint groups, where each group of users is served using the MUBF scheme. By jointly optimizing the grouping number, the user partitioning, and the beamformer design, the average sum capacity can be maximized without sacrificing user fairness. A decomposition approach is presented to decouple this problem into the user partitioning and beamformer design subproblems with the given number of groups, which can be solved using the agglomerative hierarchical clustering (AHC) algorithm and sequential parametric convex approximation (SPCA) approach, respectively. An iterative algorithm is proposed to search the optimal grouping number for the decoupled MUBFP problem by incorporating the algorithms of these two subproblems, and a suboptimal algorithm is developed to reduce the searching times with good approximation performance. Simulation results are provided to show the effectiveness of the proposed schemes in terms of convergence, average sum capacity, and complexity.
Autors: Bin Hu;Cunqing Hua;Cailian Chen;Xiaoli Ma;Xinping Guan;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 233 - 245
Publisher: IEEE
 
» Multi-Antenna Transmission in Downlink Heterogeneous Cellular Networks Under A Threshold-Based Mobile Association Policy
Abstract:
With the recent emergence of 5G era, heterogeneous cellular networks (HCNs) have invoked a popular research interest. In this paper, we provide a comprehensive analysis for multi-antenna transmissions in a multi-tier downlink HCN. We first propose a reliability-oriented threshold-based mobile association policy, where each user connects to the strongest base station from which this user can obtain the largest truncated long-term received power. Under our mobile association policy, we derive analytical expressions for the exact outage probability of an arbitrary randomly located user, along with computationally convenient lower and upper bounds. Asymptotic analysis on the outage probability shows that introducing a large access threshold into mobile association significantly decreases the outage probability. We further investigate the spectrum efficiency and the energy efficiency of the HCN. Our theoretic analysis and numerical validations show that both the spectrum and energy efficiencies can be improved by properly choosing the access threshold.
Autors: Tong-Xing Zheng;Hui-Ming Wang;Moon Ho Lee;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 244 - 256
Publisher: IEEE
 
» Multi-Parameter Interferometric Sensor Based on a Reduced Diameter Core Axial Offseted Fiber
Abstract:
We report an optical sensor based on the interference pattern created by an all-fiber Mach–Zehnder setup. This pattern is produced by the combination of the core and cladding modes that are excited on a fiber with reduced diameter fusion spliced to a single-mode fiber with a 4- core axial offset. Discrete measurements of refractive index and temperature are achieved with sensitivities of 8.8 nm/refractive index units and 39.2 pm/°C, respectively, and also distributed measurements of liquid level up to 120 mm are made with a sensitivity of 6 pm/mm.
Autors: Carlos E. S. Castellani;Hozianna C. B. Ximenes;Rodolpho L. Silva;Anselmo Frizera-Neto;Moisés R. N. Ribeiro;Maria J. Pontes;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:2, pages: 239 - 242
Publisher: IEEE
 
» Multi-Relay Communications in the Presence of Phase Noise and Carrier Frequency Offsets
Abstract:
Impairments such as time varying phase noise (PHN) and carrier frequency offset (CFO) result in loss of synchronization and poor performance of multi-relay communication systems. Joint estimation of these impairments is necessary in order to correctly decode the received signal at the destination. In this paper, we address spectrally efficient multi-relay transmission scenarios where all the relays simultaneously communicate with the destination. We propose an iterative pilot-aided algorithm based on the expectation conditional maximization for joint estimation of multipath channels, Wiener PHNs, and CFOs in decode-and-forward-based multi-relay orthogonal frequency division multiplexing systems. Next, a new expression of the hybrid Cramér–Rao lower bound (HCRB) for the multi-parameter estimation problem is derived. Finally, an iterative receiver based on an extended Kalman filter for joint data detection and PHN tracking is employed. Numerical results show that the proposed estimator outperforms existing algorithms and its mean square error performance is close to the derived HCRB at different signal-to-noise ratios for different PHN variances. In addition, the combined estimation algorithm and the iterative receiver can significantly improve average bit-error rate (BER) performance compared with existing algorithms. In addition, the BER performance of the proposed system is close to the ideal case of perfect channel impulse responses, PHNs, and CFOs estimation.
Autors: Omar H. Salim;Ali A. Nasir;Hani Mehrpouyan;Wei Xiang;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 79 - 94
Publisher: IEEE
 
» Multi-Timescale Collaborative Tracking
Abstract:
We present the multi-timescale collaborative tracker for single object tracking. The tracker simultaneously utilizes different types of “forces”, namely attraction, repulsion and support, to take advantage of their complementary strengths. We model the three forces via three components that are learned from the sample sets with different timescales. The long-term descriptive component attracts the target sample, while the medium-term discriminative component repulses the target from the background. They are collaborated in the appearance model to benefit each other. The short-term regressive component combines the votes of the auxiliary samples to predict the target’s position, forming the context-aware motion model. The appearance model and the motion model collaboratively determine the target state, and the optimal state is estimated by a novel coarse-to-fine search strategy. We have conducted an extensive set of experiments on the standard 50 video benchmark. The results confirm the effectiveness of each component and their collaboration, outperforming current state-of-the-art methods.
Autors: Dapeng Chen;Zejian Yuan;Gang Hua;Jingdong Wang;Nanning Zheng;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2017, volume: 39, issue:1, pages: 141 - 155
Publisher: IEEE
 
» Multichip LED Modules With V-Groove Surfaces for Light Extraction Efficiency Enhancements Considering Roughness Scattering
Abstract:
Although multichip light-emitting diode (LED) modules are becoming popular in high-power lighting applications, better light extraction efficiency is always desirable in the industry. In this paper, V-grooves fabricated by the low-cost dicing process have been utilized on the top face of the multichip LED module to enhance the output power. An analytical model including the consideration of surface has been established by using a fractal theory. The combined finite difference time domain and ray tracing method has been used to simulate the light extraction enhancement considering the surface roughness scattering effects. The results show 12% enhancements in the experiments when the measured surface roughness of the V-groove has RMS roughness of , which is in good agreement with the simulation result of 13.7%. The multichip LED models have been applied in indoor downlight systems and it is found that the luminous efficiency has been enhanced by 9.6% under a current of 350 mA (5.8 W) when compared with multichip LED modules without V-grooves.
Autors: Xinrui Ding;Yong Tang;Zongtao Li;Jiasheng Li;Yingxi Xie;Liwei Lin;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 182 - 188
Publisher: IEEE
 
» Multiflow application for WDM networks with multicarrier transponders serving superchannels in contentionless OXCS [invited]
Abstract:
Considerable attention from research teams has been paid to telecommunication elastic photonic networks since 2009, mainly by assessing the related extra network capacity or the mitigation of wavelength contention along the optical fibers. Now that more flexible spectral selective switches and significant modulation agile transponders are generally available off the shelf, this assessment of elasticity should become more comprehensive to make this technology even more attractive. In that context, this study examines the optimization of the stages inserting/extracting superchannels in wavelength routing optical cross-connects by using a multicarrier transponder (MC-TRx). The total add/drop capacity of the crossconnects can be dramatically increased if these MC-TRxs feature one sole common access port for all their subcarriers. But this situation calls into question the independent access to each transceiver integrated within each MC-TRx, even when it is connected to a contentionless add/drop stage based on a multicast switch. This is why this paper also describes a partial multiflow application that still complies with multicast switch (unlike the full multiflow application). These 2 multiflow options are then compared in terms of MC-TRx utilization efficiency.
Autors: Thierry Zami;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Jan 2017, volume: 9, issue:1, pages: A114 - A124
Publisher: IEEE
 
» Multilayered Aluminum Plasmonic Metasurfaces for Ultraviolet Bandpass Filtering
Abstract:
A multilayered aluminum-based metasurface is proposed toward realization of compact bandpass transmission filters for the ultraviolet spectral region. A systematic numerical study is presented that can assist in precisely tailoring the filter characteristics. The filter performance characteristics are benchmarked against previously reported filters. The proposed structures are CMOS process compatible and are suitable as replacements of bulky Wood’s filters; consequently, they are a promising step toward cost-effective UV photodetectors and multispectral imagers.
Autors: Anurag Soni;Surabhi Purohit;Ravi S. Hegde;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:1, pages: 110 - 113
Publisher: IEEE
 
» Multilevel Diversity Coding Systems: Rate Regions, Codes, Computation, & Forbidden Minors
Abstract:
The rate regions of multilevel diversity coding systems (MDCSs), a sub-class of the broader family of multi-source multi-sink networks with special structure, are investigated in a systematic way. We enumerate all non-isomorphic MDCS instances with at most three sources and four encoders. Then, the exact rate region of every one of these more than 7000 instances is proven via computations showing that the Shannon outer bound matches with a custom constructed linear code-based inner bound. Results gained from these computations are summarized in key statistics involving aspects, such as the sufficiency of scalar binary codes, the necessary size of vector binary codes, and so on. Also, it is shown how to construct the codes for an achievability proof. Based on this large repository of rate regions, a series of results about general MDCS cases of arbitrary size that they inspired is introduced and proved. In particular, a series of embedding operations that preserve the property of sufficiency of scalar or vector codes is presented. The utility of these operations is demonstrated by boiling the thousands of MDCS instances for which scalar binary (superposition) codes are insufficient down to 12 (26) forbidden the smallest embedded MDCS instances.
Autors: Congduan Li;Steven Weber;John MacLaren Walsh;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2017, volume: 63, issue:1, pages: 230 - 251
Publisher: IEEE
 
» Multimode Interference in Plasmonic Metamaterials
Abstract:
We studied multimode interference effect in a metamaterial constructed by silver nanorod pair arrays. Dipole electric resonance (ER), quadrupole magnetic resonance (MR), and Rayleigh anomaly (RA) are supported in this structure. Interference effect between either two modes is analyzed. The magnetic coupling between MR and RA, the reversed plasmon hybridization effect, and the destructive interference between ER and RA can all be brought together to realize multimode interference. Fano resonance resulted from this multimode interference is sharp, nearly symmetric, and dynamically tunable. It can be tuned linearly from ON to OFF simply through varying incident angle. The multimode interference method can cover the shortage of traditional dualmode interference and offer a better control of plasmonic metamaterials’ spectral response.
Autors: Xiaobin Hu;Tong Li;Wenbo Wang;Xin Wei;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:1, pages: 59 - 62
Publisher: IEEE
 
» Multiobjective Model For The Simultaneous Optimization Of Transportation Costs, Inventory Costs And Service Level In Goods Distribution
Abstract:
This paper presents a model formulation for the multiobjetive optimization of transportation costs, inventory costs and service level for the goods distribution process. The multiobjective model is composed by two objective functions, in which the transportation and inventory cost are optimized using the Inventory Routing Problem (IRP) and the service level is optimized using the number of accomplished time windows for the vehicles in the routing process. The model is solved using the Nondominated Sorting Genetic Algorithm II (NSGAII), implementing a novel representation of the chromosome, which allows assigning inventory and routes simultaneously. The algorithm allows calculating the Pareto Frontier for the analyzed distribution case, observing good qualities in the solution, compared with what is found in scientific literature.
Autors: Martin Dario Arango Serna;Julian Andres Zapata Cortes;
Appeared in: IEEE Latin America Transactions
Publication date: Jan 2017, volume: 15, issue:1, pages: 129 - 136
Publisher: IEEE
 
» Multipage Read for nand Flash
Abstract:
nand flash memories achieve very high densities through a series connection of all cells in a bitline. In current memories, each wordline is read independently by biasing all the other cells to act as pass transistors and sensing all the bitlines in parallel. This brief proposes a new method that reads multiple wordlines simultaneously and returns a combination of their stored information. This multipage read method is shown to be useful for equalizing the intercell interference, reduce the damage caused by erase operations, and speed up the decoding of a certain class of codes.
Autors: Tianqiong Luo;Borja Peleato;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2017, volume: 64, issue:1, pages: 76 - 80
Publisher: IEEE
 
» Multipath Streaming: Fundamental Limits and Efficient Algorithms
Abstract:
We investigate streaming over multiple links. A file is split into small units called chunks that may be requested on the various links according to some policy and received after some random delay. After a start-up time called pre-buffering time, received chunks are played at a fixed speed. There is starvation if the chunk to be played has not yet arrived. We provide lower bounds (fundamental limits) on the starvation probability of any policy. We further propose simple, order-optimal policies that require no feedback. For general delay distributions, we provide tractable upper bounds for the starvation probability of the proposed policies, allowing to select the pre-buffering time appropriately. We specialize our results to: 1) links that employ Carrier Sense Multiple Access (CSMA) or opportunistic scheduling at the packet level; 2) links shared with a primary user; and 3) links that use fair rate sharing at the flow level. We consider a generic model, so that our results give insight into the design and the performance of media streaming over: 1) wired networks with several paths between the source and the destination; 2) wireless networks featuring spectrum aggregation; and 3) multi-homed wireless networks.
Autors: Richard Combes;Habib B. A. Sidi;Salah-Eddine Elayoubi;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jan 2017, volume: 35, issue:1, pages: 188 - 199
Publisher: IEEE
 
» Multipath Wide-Bandwidth CMOS Magnetic Sensors
Abstract:
This paper proposes a multipath multisensor architecture for CMOS magnetic sensors, which effectively extends their bandwidth without compromising either their offset or resolution. Two designs utilizing the proposed architecture were fabricated in a 0.18- standard CMOS process. In the first, the combination of spinning-current Hall sensors and nonspun Hall sensors achieves an offset of 40 and a resolution of 272 in a bandwidth of 400 kHz, which is 40 times more than previous low-offset CMOS Hall sensors. In the second, the combination of spinning-current Hall sensors and pickup coils achieves the same offset, with a resolution of 210 in a further extended bandwidth of 3 MHz, which is the widest bandwidth ever reported for a CMOS magnetic sensor.
Autors: Junfeng Jiang;Kofi A. A. Makinwa;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2017, volume: 52, issue:1, pages: 198 - 209
Publisher: IEEE
 
» Multiple-Access Interference Mitigation for Acquisition of Code-Division Multiple-Access Continuous-Wave Signals
Abstract:
Multiple-access interference mitigation is important in code-division multiple-access (CDMA) systems for both information recovery and signal acquisition. Therefore, in this letter, we propose an open-loop adaptive filter based on the reiterative minimum mean-square error for the acquisition of CDMA signals. The method is based on the existing multistatic adaptive pulse compression method, appropriately adapted to the characteristics of CDMA continuous-wave signals. The efficacy of the proposed method in such systems is verified by simulation, and its superiority when compared with the existing least-mean-square method in terms of the number of reiterations is established.
Autors: Yuyao Shen;Yongqing Wang;Zhiyuan Peng;Siliang Wu;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 192 - 195
Publisher: IEEE
 
» Multiple-Reflection Noise Attenuation Using Adaptive Randomized-Order Empirical Mode Decomposition
Abstract:
We propose a novel approach for removing noise from multiple reflections based on an adaptive randomized-order empirical mode decomposition (EMD) framework. We first flatten the primary reflections in common midpoint gather using the automatically picked normal moveout velocities that correspond to the primary reflections and then randomly permutate all the traces. Next, we remove the spatially distributed random spikes that correspond to the multiple reflections using the EMD-based smoothing approach that is implemented in the domain. The trace randomization approach can make the spatially coherent multiple reflections random along the space direction and can decrease the coherency of near-offset multiple reflections. The EMD-based smoothing method is superior to median filter and prediction error filter in that it can help preserve the flattened signals better, without the need of exact flattening, and can preserve the amplitude variation much better. In addition, EMD is a fully adaptive algorithm and the parameterization for EMD-based smoothing can be very convenient.
Autors: Wei Chen;Jianyong Xie;Shaohuan Zu;Shuwei Gan;Yangkang Chen;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jan 2017, volume: 14, issue:1, pages: 18 - 22
Publisher: IEEE
 
» Multiplexing and Diversity Gains in Noncoherent Massive MIMO Systems
Abstract:
We consider a noncoherent uplink and downlink with a large antenna array at the base station. The modulation used is ON–OFF keying, with symbol-by-symbol single-user detection. A ray tracing propagation model is assumed with knowledge at the base station and transmitters of only the ray arrival angles and amplitudes. We identify the sources of performance degradation, quantify notions of diversity gain (related to the detection error performance) and multiplexing gain (related to the number of users simultaneously supported), and present numerical results to demonstrate these gains. Our results indicate that in this noncoherent system, increasing the number of antenna elements can support multiple users, with a vanishing probability of detection error, as long as the number of users is below a certain threshold which increases with the number of antennas. This contrasts with the fact that in a rich scattering propagation environment, uncoded noncoherent systems performing symbol-by-symbol detection cannot support more than one user with a vanishing probability of error.
Autors: Mainak Chowdhury;Alexandros Manolakos;Andrea Goldsmith;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 265 - 277
Publisher: IEEE
 
» Multiscale Combinatorial Grouping for Image Segmentation and Object Proposal Generation
Abstract:
We propose a unified approach for bottom-up hierarchical image segmentation and object proposal generation for recognition, called Multiscale Combinatorial Grouping (MCG). For this purpose, we first develop a fast normalized cuts algorithm. We then propose a high-performance hierarchical segmenter that makes effective use of multiscale information. Finally, we propose a grouping strategy that combines our multiscale regions into highly-accurate object proposals by exploring efficiently their combinatorial space. We also present Single-scale Combinatorial Grouping (SCG), a faster version of MCG that produces competitive proposals in under five seconds per image. We conduct an extensive and comprehensive empirical validation on the BSDS500, SegVOC12, SBD, and COCO datasets, showing that MCG produces state-of-the-art contours, hierarchical regions, and object proposals.
Autors: Jordi Pont-Tuset;Pablo Arbeláez;Jonathan T. Barron;Ferran Marques;Jitendra Malik;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2017, volume: 39, issue:1, pages: 128 - 140
Publisher: IEEE
 
» Mutually Referenced Channel Shortening
Abstract:
This letter proposes a blind channel shortening method for inter-block interference (IBI) suppression in orthogonal frequency division multiplexing (OFDM) systems. In a receiver, there are two OFDM demodulators each with a time-domain equalizer (TEQ) and a frequency-domain equalizer (FEQ). The TEQ parameters are determined such that the outputs of an FEQ are identical to those of another FEQ. It is shown that the proposed method can suppress IBI completely and eliminate the need for channel estimation, which is required by conventional methods.
Autors: Teruyuki Miyajima;Tsukasa Takahashi;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 48 - 51
Publisher: IEEE
 
» Named-Data-Networking-Based ITS for Smart Cities
Abstract:
A smart city enhances the quality of its citizens’ lives by providing ease of access to ubiquitous services through integration using communication systems at the foundation. Additionally, ITS plays a major role in making a metropolitan area into a smart city. The current IP-based solutions for ITS have slanted the performance due to high demand for data on the move, especially when the consumers become the producers. Meanwhile, NDN has evolved as a promising future Internet architecture and is being investigated extensively. In this article, we discuss the core functionality of NDN followed by our new architecture proposed for ITS in smart cities. Also, we highlight the current and future research challenges for NDN-enabled ITS in the context of smart cities.
Autors: Safdar Hussain Bouk;Syed Hassan Ahmed;Dongkyun Kim;Houbing Song;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2017, volume: 55, issue:1, pages: 105 - 111
Publisher: IEEE
 
» Nano Probing for Microwave Engineers: Calculating Probe-Sample Capacitance and Charge Distribution of a Near-Field Scanning Microwave Microscope on a Nanoscale
Abstract:
The app described in this article was presented at the student design competition of the 2016 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium. As sponsored by Technical Committee MTT-25 on RF nanotechnology, the competition's objective was to develop user-friendly interfaces to facilitate the design and application of RF nanotechnology. To this end, the app is capable of simulating the capacitance and charge distribution of the probe-sample interaction on a nanoscale in near-field scanning microscopes, such as the scanning microwave microscope (SMM), the atomic force microscope (AFM), and the scanning tunneling microscope (STM).
Autors: Xin Jin;James C.M. Hwang;Davide Mencarelli;Luca Pierantoni;Marco Farina;
Appeared in: IEEE Microwave Magazine
Publication date: Jan 2017, volume: 18, issue:1, pages: 71 - 75
Publisher: IEEE
 
» Nanoscale FETs Simulation Based on Full-Complex-Band Structure and Self-Consistently Solved Atomic Potential
Abstract:
An improved simulation scheme for investigating the performance of nanoscale FETs is developed in this paper. The total current of the MOSFET consists of two main components: thermionic current above the top of barrier of the channel calculated by ballistic approach and tunneling current computed by Wentzel–Kramer–Brillouoin approximation based on a full-complex-band structure. Furthermore, to get atomic-position-based potential profile in the nanoscale device, we self-consistently solve atomic charges and potentials in the real space along and transverse in the transport direction. The device performance calculated with this model shows excellent agreement with that obtained using non-equilibrium Green’s function solver (full quantum mechanism) but by using only one-tenth of the simulation resource. Moreover, special characteristics of insulating materials integrated with advanced device structures can also be incorporated in this Poisson solver. An example based on the negative capacitance MOSFET is examined with this model, and it shows significantly improved performance than conventional MOSFET.
Autors: Xiaoyi Zhang;Kai-Tak Lam;Kain Lu Low;Yee-Chia Yeo;Gengchiau Liang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 58 - 65
Publisher: IEEE
 
» Naphthalene Decomposition by Dielectric Barrier Discharges at Atmospheric Pressure
Abstract:
Naphthalene decomposition in O2/N2 gas mixture with different O2 concentrations has been studied in a dielectric barrier discharge reactor at atmospheric pressure. O2 played an important role in the decomposition of naphthalene, especially in the selectivities of CO and CO2. There was an optimal naphthalene decomposition rate at an O2 concentration of about 3%. The COx selectivity increased up to 83.3% gradually with the O2 concentration increasing from 1% to 20%. Nanoparticles were found in the gas samples, concentrations of which can be reduced greatly through raising the O2 concentration. The decomposition byproducts of naphthalene were obviously different under different O2 concentrations. Some nitrogenous compounds reduced but some oxygenous compounds increased with increasing O2 concentration. The mechanism of naphthalene decomposition was proposed as that naphthalene was first initiated by dehydrogenation and oxidation, and then followed by deep oxidation to CO and CO2.
Autors: Zuliang Wu;Jiaxing Wang;Jingyi Han;Shuiliang Yao;Shaojun Xu;Philip Martin;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2017, volume: 45, issue:1, pages: 154 - 161
Publisher: IEEE
 
» Natural Interaction Techniques for an Unmanned Aerial Vehicle System
Abstract:
This article provides an overview of existing interaction techniques for controlling unmanned aerial vehicle (UAV) systems. This work focuses on user interfaces with nontraditional input modalities, such as gestures, speech, and gaze direction. Although the authors analyze interaction with UAV systems, most of the findings can be applied to human-robot interaction in general. The authors report on interaction techniques employed to control single as well as multiple UAV systems, define intuitiveness of input vocabularies in the considered context, and introduce a new classification scheme based on the mental models underlying the interaction vocabulary. This article is part of a special issue on drones.
Autors: Ekaterina Peshkova;Martin Hitz;Bonifaz Kaufmann;
Appeared in: IEEE Pervasive Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 34 - 42
Publisher: IEEE
 
» Need for a transport aPI in 5G for global orchestration of cloud and networks through a virtualized infrastructure manager and planner [invited]
Abstract:
The new 5G paradigm seeks for a scalable architecture that is able to efficiently manage the increasing volume of traffic generated by smart devices to be processed in a distributed cloud infrastructure. To this end, coordinated management of the network and the cloud resources forming an end-to-end system is of great importance. Software defined networking and network function virtualization architectures are the key enablers for integrating network and cloud resources, enabling cross optimization on both sides. This optimization requires efficient resource allocation algorithms, which take into account computing and network resources. In this paper, we propose an end-to-end orchestration architecture for distributed cloud and network resources aligned with the European Telecommunications Standards Institute management and orchestration architecture. The proposed architecture includes the virtual infrastructure manager and planner (VIMaP) component to enable dynamic resource allocation for interconnected virtual instances in distributed cloud locations. A heuristic algorithm for dynamic virtual machine graphs resource allocation is included to validate the VIMaP architecture and exploit its functionalities. Moreover, the control orchestration protocol is included between the architecture components to offer end-to-end transport services. Finally, the proposed architecture is experimentally validated, and the heuristic algorithm performance is evaluated.
Autors: Arturo Mayoral;Raul Munoz;Ricard Vilalta;Ramon Casellas;Ricardo Martinez;Victor Lopez;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Jan 2017, volume: 9, issue:1, pages: A55 - A62
Publisher: IEEE
 
» Network and Service Management
Abstract:
Autors: George Pavlou;Jurgen Schonwalder;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2017, volume: 55, issue:1, pages: 196 - 196
Publisher: IEEE
 
» Networked and Distributed Control Method With Optimal Power Dispatch for Islanded Microgrids
Abstract:
In this paper, a two-layer network and distributed control method is proposed, where there is a top-layer communication network over a bottom-layer microgrid. The communication network consists of two subgraphs, in which the first is composed of all agents, while the second is only composed of controllable agents. The distributed control laws derived from the first subgraph guarantee the supply–demand balance, while further control laws from the second subgraph reassign the outputs of controllable distributed generators, which ensure active and reactive power are dispatched optimally. However, for reducing the number of edges in the second subgraph, generally a simpler graph instead of a fully connected graph is adopted. In this case, a near-optimal dispatch of active and reactive power can be obtained gradually, only if controllable agents on the second subgraph calculate set points iteratively according to our proposition. Finally, the method is evaluated over seven cases via simulation. The results show that the system performs as desired, even if environmental conditions and load demand fluctuate significantly. In summary, the method can rapidly respond to fluctuations resulting in optimal power sharing.
Autors: Qiang Li;Congbo Peng;Minyou Chen;Feixiong Chen;Wenfa Kang;Josep M. Guerrero;Derek Abbott;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 493 - 504
Publisher: IEEE
 
» Neural-Dynamics-Driven Complete Area Coverage Navigation Through Cooperation of Multiple Mobile Robots
Abstract:
Multiple robots collaboratively achieve a common coverage goal efficiently, which can improve work capacity, share coverage tasks, and reduce completion time. In this paper, a neural dynamics (ND) approach is proposed for complete area coverage navigation by multiple robots. A bioinspired neural network (NN) is designed to model the workspace and guide a swarm of robots for the coverage mission. The dynamics of each neuron in the topologically organized NN is characterized by an ND equation. Each mobile robot regards other robots as moving obstacles. Each robot path is autonomously generated from the neural activity landscape of the NN and the previous robot position. The proposed model algorithm is computationally efficient. The feasibility is validated by simulation, comparison studies, and experiments.
Autors: Chaomin Luo;Simon X. Yang;Xinde Li;Max Q.-H. Meng;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 750 - 760
Publisher: IEEE
 
» New Fountain Codes With Improved Intermediate Recovery Based on Batched Zigzag Coding
Abstract:
In this paper, two classes of fountain codes, called batched zigzag fountain codes and two-phase batched zigzag fountain codes, are proposed for the symbol erasure channel. At a cost of slightly lengthened code symbols, the involved message symbols in each batch of the proposed codes can be recovered by low complexity zigzag decoding algorithm. Thus, the proposed codes have low buffer occupancy during decoding process. These features are suitable for broadcasting to receivers with limited hardware resources. We also propose a method to obtain degree distributions of code symbols for the proposed codes via ripple size evolution by taking into account the released code symbols from the batches. We also show that the proposed codes outperform Luby transform codes and zigzag decodable fountain codes with respect to intermediate recovery rate and coding overhead when message length is short, symbol erasure rate is low, and available buffer size is limited.
Autors: Bohwan Jun;Pilwoong Yang;Jong-Seon No;Hosung Park;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 23 - 36
Publisher: IEEE
 
» New Results and Techniques for Computation of Stored Energy in Lossless/All-Pass Systems
Abstract:
Lossless and all-pass systems are energy-conservative in the sense that the energy that is extracted from the system always equals that supplied to the system. This stored energy turns out to be independent of the system realization/description. For example, there are different LC realizations of a lossless transfer function, but the energy stored can be uniquely expressed in terms of the port variables and their derivatives. This paper proposes new results and algorithms to compute the stored energy in lossless systems. We present four different techniques to compute the stored energy of lossless/all-pass systems. The first method is LC realization based (Foster, Cauer and their combinations) and the second is based on the Bezoutian of two polynomials. The notion of “balancing controllability/observability Gramians” is used for the third, while the last method is based on adjoint networks. A comparative study among the four methods shows that the first three methods are comparable with respect to computation time, while for numerical accuracy, the Bezoutian method is the best. Three different methods to compute the Bezoutian is also reported here: Euclidean long division, Pseudo-inverse method and the two dimensional discrete Fourier transform.
Autors: Chayan Bhawal;Debasattam Pal;Sandeep Kumar;Madhu N. Belur;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jan 2017, volume: 64, issue:1, pages: 72 - 85
Publisher: IEEE
 
» New Start-Up Scheme for HF Transformer Link Photovoltaic Inverter
Abstract:
Safe start-up procedure is critical for the reliable operation of power converters. The challenges in start-up schemes of high-frequency transformer link inverters involve precharge of the capacitors without significant inrush currents and overvoltages. The precharge is normally followed by enabling of the closed-loop control. The overvoltage or inrush current problems in conventional start-up schemes available in the literature are identified in this paper. A new start-up scheme is proposed which achieves the objectives of limiting inrush current and start-up overvoltages. This method does not require any additional dedicated precharge circuitry. The proposed scheme is validated using simulation and experimental results which agree with the theoretical prediction.
Autors: Abhijit Kulkarni;Vinod John;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 232 - 241
Publisher: IEEE
 
» New Testing Method for Large High-Speed Induction Motors
Abstract:
Large high-speed induction motors are being utilized more and more in the oil and gas industry to drive compressors. These machines are of particular interest for offshore installations as they significantly reduce the installed foot print. Due to the specific needs of offshore construction and commissioning programs, it is very important for the end users to validate as much as possible the drive systems during tests at manufacturers shop. These motors range from 1 to 20 MW, running at speeds between 6000 and 20 000 r/min and are generally equipped with active magnetic bearings. They are always fed by an adjustable speed drive. In order to test these motors at full power and full speed, a new test procedure has been developed and used on several machines from 1.7 to 9 MW running around 15 000 r/min. A testing configuration has been designed and implemented. The motor to be tested is coupled via a special coupling and a thrust bearing to a high speed induction generator. In order to be as close as possible to the site conditions, the project transformer, voltage-source inverter, and output filter are utilized on the test floor and used to feed the motor to be tested. This paper describes the test configuration from both an electrical and mechanical perspective. Test results are presented to show a full validation of motors characteristics and behavior allowing fast, surprise-free, commissioning on site. The challenges associated with these tests are also presented and discussed.
Autors: Lionel Durantay;Nicolas Velly;Jean-François Pradurat;Mark Chisholm;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 660 - 666
Publisher: IEEE
 
» New Year Message From the Editor-in-Chief
Abstract:
Presents the editorial for this issue of the publication.
Autors: Bin He;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jan 2017, volume: 64, issue:1, pages: 3 - 3
Publisher: IEEE
 
» Next Generation 911: Where Are We? What Have We Learned? What Lies Ahead?
Abstract:
Autors: Carol Davids;Vijay K. Gurbani;Salvatore Loreto;Ravi Subramanyan;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2017, volume: 55, issue:1, pages: 130 - 131
Publisher: IEEE
 
» Nickel Ferrite Nanoparticle Generation by Combustion Method and the Nanoparticle Structural and Magnetic Characterization and the Effect of Ball Milling
Abstract:
The combustion method has been utilized to generate nickel spinel ferrite nanoparticles. The nanoparticles were generated on two different molarities of Fe (NO3)3. 9 H2O and Ni (NO3)2. 6 H2O. The generated nanoparticles were ball milled for 3 h. Physical and chemical properties of the nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and a vibrating sample magnetometer. The crystalline structure of nanoparticles was stable after ball milling. Investigation of structural stability of ball-milled samples was done by XRD characterization. FTIR showed that oxygen–metal bonding was stronger after ball milling. Moreover, the ball-milled nanoparticles magnetically were harder than the nanoparticle without ball milling.
Autors: Hamid Reza Dehghanpour;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 5
Publisher: IEEE
 
» Ninth International Conference on Fine Particle Magnetism Preface
Abstract:
During the past 25 years since the first International Conference on Fine Particle Magnetism (ICFPM), held in Rome in 1991, there have been many developments in the methods for preparing fine particles, for characterizing them, and for implementing them in various applications. In 1991, research was focused on relaxation phenomena, spin glasses, remanence curves, and quantum tunneling. In 2016, the focus was on Néel vs. Brownian relaxation, “super” spin glasses, first order reversal curve analyses, functionalization of nanoparticles, biological applications, and implementation of fine magnetic particles in spintronic devices.
Autors: Cindi L. Dennis;George C. Hadjipanayis;Robert D. Shull;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 1
Publisher: IEEE
 
» Noise Estimation and Reduction in Magnetic Resonance Imaging Using a New Multispectral Nonlocal Maximum-likelihood Filter
Abstract:
Denoising of magnetic resonance (MR) images enhances diagnostic accuracy, the quality of image manipulations such as registration and segmentation, and parameter estimation. The first objective of this paper is to introduce a new, high-performance, nonlocal filter for noise reduction in MR image sets consisting of progressively-weighted, that is, multispectral, images. This filter is a multispectral extension of the nonlocal maximum likelihood filter (NLML). Performance was evaluated on synthetic and - and -weighted brain imaging data, and compared to the nonlocal-means (NLM) and its multispectral version, that is, MS-NLM, and the nonlocal maximum likelihood (NLML) filters. Visual inspection of filtered images and quantitative analyses showed that all filters provided substantial reduction of noise. Further, as expected, the use of multispectral information improves filtering quality. In addition, numerical and experimental analyses indicated that the new multispectral NLML filter, MS-NLML, demonstrated markedly less blurring and loss of image detail than seen with the other filters evaluated. In addition, since noise standard deviation (SD) is an important parameter for all of these nonlocal filters, a multispectral extension of the method of maximum likelihood estimation (MLE) of noise amplitude is presented and compared to both local and nonlocal MLE methods. Numerical and experimental analyses indicated the superior performance of this multispectral method for estimation of noise SD.
Autors: Mustapha Bouhrara;Jean-Marie Bonny;Beth G. Ashinsky;Michael C. Maring;Richard G. Spencer;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2017, volume: 36, issue:1, pages: 181 - 193
Publisher: IEEE
 
» Non-hermitian symmetry orthogonal frequency division multiplexing for multiple-input multiple-output visible light communications
Abstract:
Multiple-input multiple-output (MIMO) is a natural and effective way to increase the capacity of white light-emitting diode (LED) based visible light communication (VLC) systems. Orthogonal frequency division multiplexing (OFDM) using high-order modulation is another widely used technique in VLC systems. Due to the intensity modulation and direct detection nature of VLC systems, Hermitian symmetry is usually imposed in OFDM so as to obtain a real-valued signal. In this paper, we investigate a non-Hermitian symmetry OFDM (NHS-OFDM) scheme for MIMO-VLC systems. By transmitting the real and imaginary parts of a complex-valued OFDM signal via a pair of white LEDs, NHS-OFDM circumvents the constraint of Hermitian symmetry. We evaluate the performance of an indoor 2 x 2 MIMO-VLC system using conventional Hermitian symmetry-based OFDM (HS-OFDM) and NHS-OFDM, where both a non-imaging receiver and an imaging receiver are considered. Analytical results show that the system using NHS-OFDM achieves superior bit error rate (BER) performance to that using HS-OFDM, with lower or nearly the same computational complexity. The superior BER performance of NHS-OFDM-based MIMO-VLC is further verified by experiments. The experimental results demonstrate that, in a 400 Mb∕s 2x 2 MIMO-VLC system with an imaging receiver,NHS-OFDMimproves the communication coverage by about 30% compared with conventional HS-OFDM for a target BER of 3.8 x 10−3.
Autors: Chen Chen;Wen-De Zhong;Dehao Wu;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Jan 2017, volume: 9, issue:1, pages: 36 - 44
Publisher: IEEE
 
» Nonlinear Discrete Hashing
Abstract:
In this paper, we propose a nonlinear discrete hashing approach to learn compact binary codes for scalable image search. Instead of seeking a single linear projection in most existing hashing methods, we pursue a multilayer network with nonlinear transformations to capture the local structure of data samples. Unlike most existing hashing methods that adopt an error-prone relaxation to learn the transformations, we directly solve the discrete optimization problem to eliminate the quantization error accumulation. Specifically, to leverage the similarity relationships between data samples and exploit the semantic affinities of manual labels, the binary codes are learned with the objective to: 1) minimize the quantization error between the original data samples and the learned binary codes; 2) preserve the similarity relationships in the learned binary codes; 3) maximize the information content with independent bits; and 4) maximize the accuracy of the predicted labels based on the binary codes. With an alternating optimization, the nonlinear transformation and the discrete quantization are jointly optimized in the hashing learning framework. Experimental results on four datasets including CIFAR10, MNIST, SUN397, and ILSVRC2012 demonstrate that the proposed approach is superior to several state-of-the-art hashing methods.
Autors: Zhixiang Chen;Jiwen Lu;Jianjiang Feng;Jie Zhou;
Appeared in: IEEE Transactions on Multimedia
Publication date: Jan 2017, volume: 19, issue:1, pages: 123 - 135
Publisher: IEEE
 
» Nonlinear Estimator Design on the Special Orthogonal Group Using Vector Measurements Directly
Abstract:
The convergence properties of popular nonlinear attitude estimators can be traced to the choice of an attitude error function. This paper considers a nonlinear deterministic direction cosine matrix estimator whose form is derived from an alternate attitude error function. While the resulting estimator shares several properties with those previously presented in the literature, the careful selection of an attitude error function results in an estimator with superior convergence properties. The attitude estimate is propagated using a rate gyroscope measurement and corrected using two or more vector measurements. Simulation and experimental results are presented that highlight the desirable properties of the proposed estimator.
Autors: David Evan Zlotnik;James Richard Forbes;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2017, volume: 62, issue:1, pages: 149 - 160
Publisher: IEEE
 
» Nonlinear Model Reduction in Power Systems by Balancing of Empirical Controllability and Observability Covariances
Abstract:
In this paper, nonlinear model reduction for power systems is performed by the balancing of empirical controllability and observability covariances that are calculated around the operating region. Unlike existing model reduction methods, the external system does not need to be linearized but is directly dealt with as a nonlinear system. A transformation is found to balance the controllability and observability covariances in order to determine which states have the greatest contribution to the input-output behavior. The original system model is then reduced by Galerkin projection based on this transformation. The proposed method is tested and validated on a system comprised of a 16-machine 68-bus system and an IEEE 50-machine 145-bus system. The results show that by using the proposed model reduction the calculation efficiency can be greatly improved; at the same time, the obtained state trajectories are close to those for directly simulating the whole system or partitioning the system while not performing reduction. Compared with the balanced truncation method based on a linearized model, the proposed nonlinear model reduction method can guarantee higher accuracy and similar calculation efficiency. It is shown that the proposed method is not sensitive to the choice of the matrices for calculating the empirical covariances.
Autors: Junjian Qi;Jianhui Wang;Hui Liu;Aleksandar D. Dimitrovski;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 114 - 126
Publisher: IEEE
 
» Nonlinear Static State Feedback for Saturated Linear Plants via a Polynomial Approach
Abstract:
The technical note revisits the local exponential stabilization and global asymptotic stabilization problems of saturated linear systems using nonlinear control laws. The proposed nonlinear control law has rational dependence on a parameter , which is computed by solving an implicit equation depending on the state. Constructive solutions are obtained, based on a sum-of-squares formulation of the proposed conditions.
Autors: G. Valmorbida;L. Zaccarian;S. Tarbouriech;I. Queinnec;A. Papachristodoulou;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2017, volume: 62, issue:1, pages: 469 - 474
Publisher: IEEE
 
» Nonlinearity Estimation for Compensation of Phase Interpolator in Bang–Bang CDRs
Abstract:
This brief presents a technique for estimating the nonlinearity of phase interpolators (PIs) used in bang–bang phase detector-based clock and data recovery circuits. Using this estimation, the nonlinearity is compensated in a closed-loop manner. A Math model is proposed, which provides a theoretical basis for the nonlinearity estimation technique. The proposed technique is verified with the MATLAB model and with the Math model, which match within an LSB. The compensated nonlinearity lies within ±0.5 LSB of the PI for wide range of input conditions.
Autors: Archit Joshi;Mukul Sarkar;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jan 2017, volume: 25, issue:1, pages: 388 - 392
Publisher: IEEE
 
» Nonsmooth Feedback Control of Time-Delay Nonlinear Systems: A Dynamic Gain Based Approach
Abstract:
This technical note addresses the problem of global control for a class of time-delay nonlinear systems. Under a smoothness condition on the system nonlinearities, a delay-independent, non-smooth dynamic state compensator is constructed by developing a dynamic gain based design method. With the help of appropriate Lyapunov-Krasovskii functionals, it is shown that all the states of the time-delay nonlinear system can be regulated to the origin while maintaining boundedness of the closed-loop system. A benchmark example is given to illustrate the effectiveness of the proposed non-smooth feedback controller.
Autors: Xu Zhang;Wei Lin;Yan Lin;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2017, volume: 62, issue:1, pages: 438 - 444
Publisher: IEEE
 
» Nopol: Automatic Repair of Conditional Statement Bugs in Java Programs
Abstract:
We propose Nopol, an approach to automatic repair of buggy conditional statements (i.e., if-then-else statements). This approach takes a buggy program as well as a test suite as input and generates a patch with a conditional expression as output. The test suite is required to contain passing test cases to model the expected behavior of the program and at least one failing test case that reveals the bug to be repaired. The process of Nopol consists of three major phases. First, Nopol employs angelic fix localization to identify expected values of a condition during the test execution. Second, runtime trace collection is used to collect variables and their actual values, including primitive data types and objected-oriented features (e.g., nullness checks), to serve as building blocks for patch generation. Third, Nopol encodes these collected data into an instance of a Satisfiability Modulo Theory (SMT) problem; then a feasible solution to the SMT instance is translated back into a code patch. We evaluate Nopol on 22 real-world bugs (16 bugs with buggy if conditions and six bugs with missing preconditions) on two large open-source projects, namely Apache Commons Math and Apache Commons Lang. Empirical analysis on these bugs shows that our approach can effectively fix bugs with buggy if conditions and missing preconditions. We illustrate the capabilities and limitations of Nopol using case studies of real bug fixes.
Autors: Jifeng Xuan;Matias Martinez;Favio DeMarco;Maxime Clément;Sebastian Lamelas Marcote;Thomas Durieux;Daniel Le Berre;Martin Monperrus;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Jan 2017, volume: 43, issue:1, pages: 34 - 55
Publisher: IEEE
 
» Novel Asymmetric Slant Field Plate Technology for High-Speed Low-Dynamic Ron E/D-mode GaN HEMTs
Abstract:
In this letter, we discuss a novel asymmetric field plate structure utilizing a slanted field plate (FP) engineered to appropriately distribute the electric field on GaN high-electron mobility transistors (HEMTs) scaled for low-loss, high-speed power switch applications. A uniform electric field distribution achieved with the slant FP enables an optimum device design, where a low-dynamic ON-resistance () and high breakdown voltage are obtained simultaneously by minimizing the gate-drain distance. The optimized FP design demonstrated a low of 2.3 (2.1) -mm at a quiescent drain voltage of 50V in -mode (-mode) HEMTs with a breakdown voltage of 138 V (146 V). The corresponding high-frequency performance of E-mode (D-mode) HEMTs of peak /100 GHz (53/100 GHz) yielded a decent product in the range of 31.0–34.5 (28.0–33.3) -nC. This new slant FP technology combined with scaled epitaxial structure (for short ) and reduced access resistances, using n+ GaN ohmic contacts, greatly enhances performance and desig- flexibility of high-speed, low-loss, GaN power switch devices.
Autors: Joel Wong;Keisuke Shinohara;Andrea L. Corrion;David F. Brown;Zenon Carlos;Adam Williams;Yan Tang;John F. Robinson;Isaac Khalaf;Helen Fung;Adele Schmitz;Thomas Oh;Samuel Kim;Steven Chen;Shawn Burnham;Alex Margomenos;Miroslav Micovic;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2017, volume: 38, issue:1, pages: 95 - 98
Publisher: IEEE
 
» Novel Double Clamp Methodology to Reduce Shielded Cable Radiated Emissions Initiated by Electronic Device Switching
Abstract:
A new “double clamp methodology” (DCM) is proposed that can suppress a cable's peak radiated emission in a band centered around noise frequency that is generated by common-mode (CM) electrical noise current flowing in any product containing pulsed switching devices connected to a shielded cable. DCM is a cable grounding technique that clamps or terminates a shielded cable in two places. The first shield clamp at the switching device output uses traditional well-known cable termination techniques, e.g., 360° low inductance shield connection to ground. A second shield clamp can be placed at a predetermined cable length from the first, where the cable resonant frequency is known to have ultralow CM impedance at noise frequency . The cable loop between shield clamp terminations sets up a resonant low impedance at that diverts CM current to the ground plane inside the product, so CM current entering a shielded cable is reduced as well as radiated electric field emissions. Analytical and measurement techniques are provided to determine the correct cable clamp length. Experimental test results confirm DCM effectively controls CM noise current and resulting peak radiated emissions by 12 dB⋅µV/m (∼4×), without external suppression components added.
Autors: Zoran Vrankovic;Gary L. Skibinski;Craig Winterhalter;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 327 - 339
Publisher: IEEE
 
» Novel Dual-Mode Bandpass Filters Based on SIW Resonators under Different Boundaries
Abstract:
Two novel substrate integrated waveguide (SIW) resonators under different boundaries are proposed and analyzed. The closed-form solutions of the guided-mode field and the formulas for calculating the resonant frequencies of the SIW resonators under different boundaries are given. The coexistence mechanism of quasi-TEM (TE00) and TE mode was illustrated by the proposed equivalent principle. Two modes of each filter, TE100 (TEM mode) and TE102, TE001 (TEM mode) and TE201, can be tuned independently by the perturbation slotlines. Finally, two dual-mode SIW bandpass filters utilizing the two SIW resonators are fabricated to demonstrate the proposed method. The measured results are in agreement with the simulated results.
Autors: Shuxing Wang;Dewei Zhang;Yi Zhang;Liu Qing;Dongfang Zhou;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2017, volume: 27, issue:1, pages: 28 - 30
Publisher: IEEE
 
» Novel Intercell Interference Mitigation Algorithms for Multicell OFDMA Systems With Limited Base Station Cooperation
Abstract:
Resource allocation in multicell downlink orthogonal frequency division multiple-access (OFDMA) systems is investigated, where base stations (BSs) first independently carry out subcarrier allocation and then mitigate intercell interference (InterCI) with the aid of very limited BS cooperation. Two novel InterCI mitigation algorithms are proposed. The first one is the distributed decision making assisted cooperation (DDMC) algorithm, and the second one is the centralized decision making assisted cooperation (CDMC) algorithm. When employing the DDMC algorithm, each BS independently makes the InterCI mitigation decisions (IMDs). By contrast, when employing the CDMC algorithm, the centralized IMDs are made with the aid of the cell-edge users' discrete InterCI information sharing among BSs. While both algorithms motivate maximization of the spectral efficiency (sum rate), the CDMC algorithm also aims to maximize the frequency reuse factor. In this paper, we study and compare the performance, including spectral efficiency of cell-edge users, frequency reuse factor, and overhead, of the multicell downlink OFDMA systems employing the proposed and other InterCI mitigation algorithms. Our studies show that both the DDMC and CDMC algorithms can achieve better spectral efficiency performance than the existing on–off power (OOP) algorithm. Moreover, the CDMC algorithm is capable of achieving performance close to the upper bound attained by the so-called full InterCI information assisted decision making (FIIDM) algorithm, which uses exhaustive search to determine the IMDs. Additionally, the CDMC algorithm is demonstrated to have the highest frequency reuse factor, in addition to its spectral efficiency advantage.
Autors: Jia Shi;Lie-Liang Yang;Qiang Ni;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 406 - 420
Publisher: IEEE
 
» Novel Metric Describing Total Nonlinearity of Power Amplifier With a Corresponding Figure of Merit for Linearity Evaluation and Optimization
Abstract:
In this work, we present a novel metric for the total PA or Tx nonlinear distortion in form of an output signal nonlinear power. The presented metric takes into account all sources of distortion and it evaluates a nonlinear distortion that appears inside and outside of the signal bandwidth. Furthermore, the FOM that acts as a signal to total distortion ratio STDR is developed. Optimizing the PA or Tx system for maximum STDR maximizes the ratio of the linear over nonlinear power of the output signal. That ensures optimal linearity and output power level. These characteristics make this technique convenient for a overall linearity evaluation and for optimization of the different linearity improvement techniques applied to the PA or Tx system.
Autors: Dragan Gecan;Karl M. Gjertsen;Morten Olavsbråten;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2017, volume: 27, issue:1, pages: 85 - 87
Publisher: IEEE
 
» Novel Pilot Position Selection and Signal Reconstruction Methods for Frequency-Domain Pilot Multiplexing Techniques of SC-FDE
Abstract:
The frequency-domain pilot multiplexing technique (FDPMT) has recently emerged as an appealing technique for channel estimation in single-carrier frequency-domain equalization (SC-FDE) systems due to the high spectral efficiency it promises. However, the performance of the FDPMT system is significantly affected by the signal distortion level, which depends on the pilot position selection (PPS) strategy at the transmitter and the signal reconstruction (SR) ability of the receiver. In this paper, the relationship between the interference pattern and the loss of equally spaced tones is discovered. By exploiting this relationship, we propose a novel PPS method and a novel SR method. The proposed PPS method, which is based on the minimization of the most severe intersymbol interference (ISI) experienced by those subblocks decimated from the transmitted signal block, dispenses with a priori knowledge of the channel statistics and imposes very low computational cost to the transmitter. The proposed SR method, which is based on the maximum-likelihood criterion, can be carried out subblock by subblock in parallel and sample by sample within each subblock, saving the computational complexity and time consumption of the receiver. Simulation results in terms of bit error rate (BER) corroborate the superiority of both proposed methods over their existing counterparts in various channels of interest.
Autors: Beixiong Zheng;Fangjiong Chen;Miaowen Wen;Fei Ji;Hua Yu;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 502 - 512
Publisher: IEEE
 
» Novel Robust Band-Limited Signal Detection Approach Using Graphs
Abstract:
In this letter, a novel graph-based adequate and concise information representation paradigm is explored. This new signal representation framework can provide a promising alternative for manifesting the essential structure of the communication signals. A typical application, namely, band-limited signal detection, can thus be carried out using our proposed new graph-based signal characterization. According to Monte Carlo simulation results, the proposed graph-based signal detection method leads to the outstanding performance, compared with other existing techniques especially when the signal-to-noise ratio is rather small.
Autors: Kun Yan;Hsiao-Chun Wu;Hailin Xiao;Xiangli Zhang;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 20 - 23
Publisher: IEEE
 
» Novel Surface Impedance Modeling for Broadband Parameter Extraction of 3-D Interconnects
Abstract:
A novel boundary integral equation based method for modeling 3-D interconnects is proposed to compute the equivalent surface impedance in this letter. Differing from the traditional algorithm to discretize the conductor cross section, the proposed method only discretizes the contour of the conductor cross section, thus reducing the CPU time and memory cost. The loss characteristics of conductors describing the skin effect are taken into account through Green’s function. The equivalent surface impedance model can be used to simplify electromagnetic simulation only using electric field integral equation. Numerical results show that the proposed method is both efficient and accurate in a broadband frequency, which is suited for modeling of 3-D interconnects and integrated passive structures.
Autors: Yu Zhao;Feng Ling;Junfa Mao;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2017, volume: 27, issue:1, pages: 7 - 9
Publisher: IEEE
 
» Novel Tunable Bandstop Resonators in SIW Technology and Their Application to a Dual-Bandstop Filter with One Tunable Stopband
Abstract:
Two novel tunable bandstop resonators in substrate integrated waveguide (SIW) technology are presented: a ridged SIW resonator and an open-ended coplanar waveguide (CPW) resonator that is etched into the SIW’s top metallization. The ridged SIW resonator shows a tuning range of 200 MHz at 5.54 GHz. The CPW resonator has a tuning range of 600 MHz at 3.8 GHz. The two bandstop resonators are combined to design a dual-band bandstop filter with one tunable stopband. Measured results confirm that the tunable bandstop circuits presented in this letter can be effectively used in reconfigurable SIW systems.
Autors: Mahbubeh Esmaeili;Jens Bornemann;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2017, volume: 27, issue:1, pages: 40 - 42
Publisher: IEEE
 
» Novel Wideband Bandpass Filter with Dual Notched Bands Using Stub-Loaded Resonators
Abstract:
In this letter, a novel wideband bandpass filter with dual notched bands using stub-loaded resonators is proposed. By using the signal interaction of two transmission paths, a wideband passband and two notched bands can be independently achieved and designed. By cascading two back-to-back vertical transitions, a six-pole wideband filter with equal ripple filtering response is synthetically analyzed. The dual notched bands are controlled by the even- and odd-mode resonant frequencies of the stub-loaded resonator. As a design example, the proposed wideband filter with dual notched bands is simulated and fabricated. The desired wideband filtering response is experimentally validated, and two notched bands are measured at 3.04 and 3.85 GHz, respectively.
Autors: Li Yang;Wai-Wa Choi;Kam-Weng Tam;Lei Zhu;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2017, volume: 27, issue:1, pages: 25 - 27
Publisher: IEEE
 
» Nuclear Norm Based Matrix Regression with Applications to Face Recognition with Occlusion and Illumination Changes
Abstract:
Recently, regression analysis has become a popular tool for face recognition. Most existing regression methods use the one-dimensional, pixel-based error model, which characterizes the representation error individually, pixel by pixel, and thus neglects the two-dimensional structure of the error image. We observe that occlusion and illumination changes generally lead, approximately, to a low-rank error image. In order to make use of this low-rank structural information, this paper presents a two-dimensional image-matrix-based error model, namely, nuclear norm based matrix regression (NMR), for face representation and classification. NMR uses the minimal nuclear norm of representation error image as a criterion, and the alternating direction method of multipliers (ADMM) to calculate the regression coefficients. We further develop a fast ADMM algorithm to solve the approximate NMR model and show it has a quadratic rate of convergence. We experiment using five popular face image databases: the Extended Yale B, AR, EURECOM, Multi-PIE and FRGC. Experimental results demonstrate the performance advantage of NMR over the state-of-the-art regression-based methods for face recognition in the presence of occlusion and illumination variations.
Autors: Jian Yang;Lei Luo;Jianjun Qian;Ying Tai;Fanlong Zhang;Yong Xu;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2017, volume: 39, issue:1, pages: 156 - 171
Publisher: IEEE
 
» Nurturing a Path to Sucess [Pathways]
Abstract:
Reports on the activities, education , and career development of a young professional in the industry applications arena.
Autors: David Eng;
Appeared in: IEEE Industry Applications Magazine
Publication date: Jan 2017, volume: 23, issue:1, pages: 83 - 85
Publisher: IEEE
 
» Ocean Surface Wind Retrieval Using SMAP L-Band SAR
Abstract:
The soil moisture active passive (SMAP) L-band synthetic aperture radar (SAR) could continuously provide global km scale ocean surface wind observations, which had a better coverage than other SARs and a higher spatial resolution than scatterometers. This paper investigates SMAP normalized radar cross sections (NRCS) dependence on wind vectors using more than 5 million matchups consisting of Defense Meteorological Satellite Program F17 Special Sensor Microwave Image/Sounder wind speed, National Center for Environmental Predication wind direction and SMAP L-band NRCS. An L-band geophysical model function (GMF) is proposed for SMAP wind retrieval on the basis of these matchups, and it indicates wind speed and direction dependence of SMAP L-band NRCS for about 40° incidence angle and 0–25 m/s wind speed range in both HH and VV polarization. The wind speed dependence increases rapidly with wind speed, and HH-polarized one is greater than VV polarization. The upwind–downwind difference for HH polarization is greater than that for VV polarization. A negative upwind–crosswind asymmetry occurs for HH- and VV-polarized backscatter at lower wind speeds. The retrieved SMAP wind speed using the proposed GMF is validated by using National Data Buoy Center buoy winds. The root mean square differences and biases are 1.77 and 0.19 m/s, respectively. The accuracies of SMAP wind speeds at 0–10 m/s range are better than those at higher wind speed range. In addition, SMAP wind speeds in upwind and downwind directions are relatively more accurate than those in crosswind directions.
Autors: Xuan Zhou;Jinsong Chong;Xiaofeng Yang;Wei Li;Xiaoxuan Guo;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 65 - 74
Publisher: IEEE
 
» On Achievable Rate of User Selection for MIMO Broadcast Channels With Limited Feedback
Abstract:
We consider the block diagonalization (BD) and user selection based on limited feedback in multiple antenna broadcast channels. With limited feedback, due to the imperfect channel state information at the transmitter (CSIT), BD cannot completely eliminate multiuser interference, and the throughput is correspondingly lower than that achieved with perfect CSIT. Nevertheless, the achievable multiuser diversity gain can be the same, such that limited-feedback-based BD can achieve an optimal throughput growth as the number of users increases. To show this, we first propose a channel quality indicator (CQI) for user selection. The CQI is designed to accurately estimate an achievable rate of each user and is given by an expected rate, where the expectation is solely taken over precoding matrices which cannot be known at the feedback stage. With the proper CQI, user selection can benefit from a large number of users in the system. As a result, we show that the BD can achieve an asymptotically optimal growth in throughput with the proposed CQI, based solely on a finite-rate feedback of channel information.
Autors: Moonsik Min;Yo-Seb Jeon;Gi-Hong Im;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 122 - 135
Publisher: IEEE
 
» On Data Integrity Attacks Against Real-Time Pricing in Energy-Based Cyber-Physical Systems
Abstract:
In this paper, we investigate a novel real-time pricing scheme, which considers both renewable energy resources and traditional power resources and could effectively guide the participants to achieve individual welfare maximization in the system. To be specific, we develop a Lagrangian-based approach to transform the global optimization conducted by the power company into distributed optimization problems to obtain explicit energy consumption, supply, and price decisions for individual participants. Also, we show that these distributed problems derived from the global optimization by the power company are consistent with individual welfare maximization problems for end-users and traditional power plants. We also investigate and formalize the vulnerabilities of the real-time pricing scheme by considering two types of data integrity attacks: Ex-ante attacks and Ex-post attacks, which are launched by the adversary before or after the decision-making process. We systematically analyze the welfare impacts of these attacks on the real-time pricing scheme. Through a combination of theoretical analysis and performance evaluation, our data shows that the real-time pricing scheme could effectively guide the participants to achieve welfare maximization, while cyber-attacks could significantly disrupt the results of real-time pricing decisions, imposing welfare reduction on the participants.
Autors: Xialei Zhang;Xinyu Yang;Jie Lin;Guobin Xu;Wei Yu;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jan 2017, volume: 28, issue:1, pages: 170 - 187
Publisher: IEEE
 
» On Energy-Efficient Offloading in Mobile Cloud for Real-Time Video Applications
Abstract:
Batteries of modern mobile devices remain severely limited in capacity, which makes energy consumption a key concern for mobile applications, particularly for the computation-intensive video applications. Mobile devices can save energy by offloading computation tasks to the cloud, yet the energy gain must exceed the additional communication cost for cloud migration to be beneficial. The situation is further complicated by real-time video applications that have stringent delay and bandwidth constraints. In this paper, we closely examine the performance and energy efficiency of representative mobile cloud applications under dynamic wireless network channels and state-of-the-art mobile platforms. We identify the unique challenges of and opportunities for offloading real-time video applications and develop a generic model for energy-efficient computation offloading accordingly in this context. We propose a scheduling algorithm that makes adaptive offloading decisions in fine granularity in dynamic wireless network conditions and verify its effectiveness through trace-driven simulations. We further present case studies with advanced mobile platforms and practical applications to demonstrate the superiority of our solution and the substantial gain of our approach over baseline approaches.
Autors: Lei Zhang;Di Fu;Jiangchuan Liu;Edith Cheuk-Han Ngai;Wenwu Zhu;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jan 2017, volume: 27, issue:1, pages: 170 - 181
Publisher: IEEE
 
» On Finite-State Stochastic Modeling and Secure Estimation of Cyber-Physical Systems
Abstract:
The problem of secure state estimation and attack detection in cyber-physical systems is considered in this paper. A stochastic modeling framework is first introduced, based on which the attacked system is modeled as a finite-state hidden Markov model with switching transition probability matrices controlled by a Markov decision process. Based on this framework, a joint state and attack estimation problem is formulated and solved. Utilizing the change of probability measure approach, we show that an unnormalized joint state and attack distribution conditioned on the sensor measurement information evolves in a linear recursive form, based on which the optimal estimates can be further calculated by evaluating the normalized marginal conditional distributions. The estimation results are further applied to secure estimation of stable linear Gaussian systems, and extensions to more general systems are also discussed. The effectiveness of the results are illustrated by numerical examples and comparative simulation.
Autors: Dawei Shi;Robert J. Elliott;Tongwen Chen;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2017, volume: 62, issue:1, pages: 65 - 80
Publisher: IEEE
 
» On Ingleton-Violating Finite Groups
Abstract:
Given discrete random variables, its entropy vector is the -dimensional vector obtained from the joint entropies of all non-empty subsets of the random variables. It is well known that there is a close relation between such an entropy vector and a certain group-characterizable vector obtained from a finite group and of its subgroups; indeed, roughly speaking, knowing the region of all such group-characterizable vectors is equivalent to knowing the region of all entropy vectors. This correspondence may be useful for characterizing the space of entropic vectors and for designing network codes. If one restricts attention to abelian groups then not all entropy vectors can be obtained. This is an explanation for the fact shown by Dougherty et al. that linear network codes cannot achieve capacity in general network coding problems (since linear network codes come from abelian groups). All abelian group-characterizable vectors, and by fiat all entropy vectors generated by linear network codes, satisfy a linear inequality called the Ingleton inequality. General entropy vectors, however, do not necessarily have this property. It is, therefore, of interest to identify groups that violate the Ingleton inequality. In this paper, we study the problem of finding nonabelian finite groups that yield characterizable vectors, which violate the Ingleton inequality. Using a refined computer search, we find the symmetric group to be the smallest group that violates the Ingleton inequality. Careful study of the structure of this group, and its subgroups, reveals that it belongs to the Ingleton-violating family with a prime power , i.e., the projective group of nonsingular matrices with entries in . We further interpret this family of groups, and their subgroups, using the theory of group actions and identify the subgroups as certain stabilizers. We also extend the construction to more general groups such as and . The families of groups identified here are therefore good candidates for constructing network codes more powerful than linear network codes, and we discuss some considerations for constructing such group network codes.
Autors: Wei Mao;Matthew Thill;Babak Hassibi;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2017, volume: 63, issue:1, pages: 183 - 200
Publisher: IEEE
 
» On Jamming Against Wireless Networks
Abstract:
In this paper, we study jamming attacks against wireless networks. Specifically, we consider a network of base stations (BSs) or access points (APs) and investigate the impact of a fixed number of jammers that are randomly deployed according to a Binomial point process. We investigate the network performance in terms of: 1) the outage probability and 2) the error probability of a victim receiver in the downlink of this wireless network. We derive analytical expressions for both these metrics and discuss in detail how the jammer network must adapt to the various wireless network parameters in order to effectively attack the victim receivers. For instance, we will show that with only 1 jammer per BS/AP: 1) the outage probability of the wireless network can be increased from 1% (as seen in the non-jamming case) to 80% and 2) when retransmissions are used, the jammers cause the effective network activity factor (and hence the interference among the BSs) to be doubled. Furthermore, we show that the behavior of the jammer network as a function of the BS/AP density is not obvious. In particular, a non-trivial behavior is seen, which indicates that the number of jammers required to attack the wireless network must scale with the BS density only until a certain value beyond which it decreases. In the context of error probability of the victim receiver, we study whether or not some recent results related to jamming in the point-to-point link scenario can be extended to the case of jamming against wireless networks. Numerical results are presented to validate all the theoretical inferences presented.
Autors: SaiDhiraj Amuru;Harpreet S. Dhillon;R. Michael Buehrer;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 412 - 428
Publisher: IEEE
 
» On the Application of Single-Phase Voltage Sag Compensators in Three-Phase Systems
Abstract:
Voltage sag is one of the most frequent power quality problems found in industries and power system. Its effects can be numerous such as control equipment trips, process shutdown, and production losses. This paper reports three years of voltage sag measurements collected in a research lab. This site is located near many metal industries which lead to a correlation between the obtained results and possible voltage sags in these industries. From the resulting analysis, this paper proposes the usage of single-phase voltage sag compensators in three-phase systems aiming a cost-effective solution. This procedure would not wholly eliminate the voltage sag incidence but it would diminish voltage sag effects on electrical loads.
Autors: Igor Amariz Pires;Filipe Dias de Oliveira;Sidelmo Magalhaes Silva;Braz de Jesus Cardoso Filho;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 630 - 637
Publisher: IEEE
 
» On the Calculation of the Incomplete MGF With Applications to Wireless Communications
Abstract:
The incomplete moment generating function (IMGF) has paramount relevance in communication theory, since it appears in a plethora of scenarios when analyzing the performance of communication systems. We here present a general method for calculating the IMGF of any arbitrary fading distribution. Then, we provide exact closed-form expressions for the IMGF of the very general - shadowed fading model, which includes the popular -, -, Rician shadowed, and other classical models as particular cases. We illustrate the practical applicability of this result by analyzing several scenarios of interest in wireless communications: 1) physical layer security in the presence of an eavesdropper; 2) outage probability analysis with interference and background noise; 3) channel capacity with side information at the transmitter and the receiver; and 4) average bit-error rate with adaptive modulation, when the fading on the desired link can be modeled by any of the aforementioned distributions.
Autors: F. Javier Lopez-Martinez;Juan M. Romero-Jerez;Jose F. Paris;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 458 - 469
Publisher: IEEE
 
» On the Capacity-Performance Trade-Off of Online Policy in Delayed Mobile Offloading
Abstract:
WiFi offloading, where mobile users opportunistically obtain data through WiFi rather than cellular networks, is a promising technique for greatly improving spectrum efficiency and reduce cellular network congestion. We consider a system where the service provider deploys multiple WiFi hotspots to offload mobile traffic, and study the scheduling policy to maximize the amount of offloaded data. Since users’ movements are unpredictable, we focus on online scheduling policy, where APs have no knowledge of users’ mobility patterns. We study the performance of online policies by comparing them against the optimal offline policy. We prove that any work-conserving policy is able to offload at least half as much data as the offline policy, and then propose an online policy such that when the requested data by each user is very large, the policy can offload as much data as the offline policy, where is Euler’s constant. We further study the case where the service provider can increase the capacity of WiFi so as to provide some guarantees on the amount of offloaded data. We derive a lower-bound on the trade-off between capacity and the amount of offloaded data, and propose a simple online policy that achieves this lower bound. In addition, we show that our policy only needs half as much capacity as current mechanisms to provide the same performance guarantee.
Autors: Han Deng;I-Hong Hou;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 526 - 537
Publisher: IEEE
 
» On the DMT of RF Energy Harvesting-Based Dynamic Decode-and-Forward Relaying
Abstract:
A multiple relay-based system, where all the relay nodes powered by radio frequency-based energy harvesting (EH), is considered. The present letter characterizes the diversity-multiplexing tradeoff (DMT) for EH-based dynamic decode-and-forward (EH-DDF) protocol for independent quasi-static Rayleigh faded channels. It is shown that the achievable diversity gain of EH-DDF improves with the reduction in the EH intervals. However, it is observed that the performance difference exists between classical DDF and EH-DDF even for infinitesimal harvest duration in lower multiplexing gain region.
Autors: Yepuri Sudhakara Rao;Rajendra Prasad Sirigina;A. S. Madhukumar;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 200 - 203
Publisher: IEEE
 
» On the Loadability Sets of Power Systems—Part I: Characterization
Abstract:
This two-part paper presents a framework for the characterization and minimal representation of the feasibility regions of power systems in the demand space. These feasibility regions are called loadability sets, and they represent the projection of generation-demand-network space onto the demand space only. Loadability sets have been characterized previously for power systems with either no or a single active line flow constraint. In Part I of this two-part paper, we generalize this characterization to power systems with any number of active line flow constraints. The proposed characterization approach makes use of the Fourier–Motzkin elimination method which leads to the generation of a large number of constraints. We set course to address this shortcoming in the second part of this paper. The notion of umbrella set is revisited in Part II to identify and remove the redundant constraints produced in the loadability set characterization process. The outcome of the proposed framework is the minimal representation of the power system feasibility region in the demand space. We envision multiple applications for the proposed framework in power system planning, operations planning, and real-time operation.
Autors: Amir Abiri Jahromi;François Bouffard;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 137 - 145
Publisher: IEEE
 
» On the Loadability Sets of Power Systems—Part II: Minimal Representations
Abstract:
The first part of this two-part paper developed the framework for characterizing the feasibility regions of power systems in the demand space. This characterization, however, leads to the generation of a large number of extraneous constraints as an unwelcome byproduct. This shortcoming motivates the second part of this paper series, whose objective is the achievement of a minimal representation for loadability sets through an offline process. Thus, in this paper, we set forth to eliminate efficiently redundant constraints with the proposal of an enhanced umbrella constraint discovery (E-UCD) problem formulation. The use of E-UCD in this paper is fourfold: 1) It serves to identify redundant line flow constraints not potentially shaping the feasibility regions of power systems in the generation-demand space. 2) It serves to determine the maximum number of line flow limits that could ever become active simultaneously in a given power system. 3) It pinpoints the generators who have the ability to become pivotal in relieving network congestion. 4) It is used to identify redundant constraints generated, while generation dispatch variables are projected from the generation-demand space onto the demand space. Experiments are carried out on the standard IEEE test systems to show that the minimal representations of loadability sets contain a reasonable number of constraints. Thus, the application of loadability sets to operation and planning problems will result in computational savings.
Autors: Amir Abiri-Jahromi;François Bouffard;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 146 - 156
Publisher: IEEE
 
» On the Non-Existence of Certain Classes of Generalized Bent Functions
Abstract:
We obtain new non-existence results of generalized bent functions from to (called type ). The first case is a class with types, where . The second case contains two types and .
Autors: Chang Lv;Jianing Li;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2017, volume: 63, issue:1, pages: 738 - 746
Publisher: IEEE
 
» On the Role of Transmit Correlation Diversity in Multiuser MIMO Systems
Abstract:
Correlation across transmit antennas in multiple-input multiple-output (MIMO) systems has been studied in various scenarios and has been shown to be detrimental or provide benefits depending on the particular system and underlying assumptions. In this paper, we investigate the effect of transmit correlation on the capacity of the Gaussian MIMO broadcast channel, with a particular interest in the large-scale array (or massive MIMO) regime. To this end, we introduce a new type of diversity, referred to as transmit correlation diversity, which captures the fact that the channel vectors of different users may have different channel covariance matrices spanning often nearly mutually orthogonal subspaces. In particular, when taking the cost of downlink training properly into account, transmit correlation diversity can yield significant capacity gains in all regimes of interest. Our analysis shows that the system multiplexing gain can be increased by a factor up to , where is the number of antennas and is the common rank of the users channel covariance matrices, with respect to standard schemes that are agnostic of the transmit correlation diversity and treat the channels as if they were isotropically distributed. Thus, this new form of diversity reveals itself as a valuable “new resource” in multiuser communications.
Autors: Junyoung Nam;Giuseppe Caire;Jeongseok Ha;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2017, volume: 63, issue:1, pages: 336 - 354
Publisher: IEEE
 
» On the Stability of the FDTD Implementation of High Order Rational Constitutive Relations
Abstract:
The stability of the finite difference time domain (FDTD) implementation of high order rational constitutive relations is studied by means of the root-locus method. The proposal equally is applicable to electrically and/or magnetically dispersive models. It is shown that by adopting the bilinear transformation into the constitutive relation FDTD implementation, the conventional non-dispersive Courant-Friedrichs-Lewy stability limit will be retained. Numerical simulations carried out for a four-pole complex rational function are included to validate both the stability and the accuracy of the derived equations.
Autors: Omar Ramadan;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2017, volume: 27, issue:1, pages: 4 - 6
Publisher: IEEE
 
» On the Solution of Revenue- and Network-Constrained Day-Ahead Market Clearing Under Marginal Pricing—Part I: An Exact Bilevel Programming Approach
Abstract:
The first of this two-paper series addresses a practical day-ahead auction model, where generation revenue constraints are explicitly incorporated in the problem formulation, as routinely done in several national electricity markets across Europe. The revenue-constrained market-clearing procedure includes the effect of the transmission network, inter-temporal constraints associated with generation scheduling, demand-side bidding, and marginal pricing. This auction design is an instance of price-based market clearing which features two major complicating factors. First, locational marginal prices become decision variables of the optimization process. In addition, producer revenues are formulated as bilinear and highly nonconvex products of power outputs and market-clearing prices. The resulting problem is formulated as a mixed-integer nonlinear bilevel program with bilinear terms for which available solution techniques rely on heuristics, approximations, or modeling simplifications. This paper presents a novel and exact methodology whereby the original problem is recast as an equivalent single-level mixed-integer linear program. As a consequence, finite convergence to optimality is guaranteed and the use of standard commercial software is allowed. The proposed transformation is based on duality theory of linear programming, Karush-Kuhn-Tucker optimality conditions, and integer algebra results. In the second part of this two-paper series, numerical results from several case studies illustrate the effective performance of the proposed solution approach.
Autors: Ricardo Fernández-Blanco;José M. Arroyo;Natalia Alguacil;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 208 - 219
Publisher: IEEE
 
» On-Chip SDM Switching for Unicast, Multicast, and Traffic Grooming in Data Center Networks
Abstract:
This letter reports on the use of a novel photonic integrated circuit that facilitates multicast and grooming in an optical data center architecture. The circuit allows for on-chip spatial multiplexing and demultiplexing as well as fiber core switching. Using this device, we experimentally verify that multicast and/or grooming can be successfully performed along the full range of output ports, for different group sizes and different power ratios. Moreover, we experimentally demonstrate SDM transmission and 5 Tb/s switching using the on-chip fiber switch with integrated fan-in/fan-out devices and achieve error-free performance (BER) for a network scenario, including simultaneous unicast/multicast switching and traffic grooming.
Autors: Valerija Kamchevska;Yunhong Ding;Kjeld Dalgaard;Michael Berger;Leif K. Oxenløwe;Michael Galili;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:2, pages: 231 - 234
Publisher: IEEE
 
» On-Road Vehicle Trajectory Collection and Scene-Based Lane Change Analysis: Part I
Abstract:
This two-part paper aims to study lane change behaviors at the tactical level from an on-road perspective, with a special focus on analyzing the interactions between an ego and surrounding vehicles during the procedure. Part I addresses vehicle trajectory collection, whereas Part II addresses lane change extraction and scene-based behavioral analysis. Different from the general technique of moving object detection and tracking, trajectory collection for tactical driving behavior study is required to have the properties of consistency, completeness, continuity, and accuracy. This paper proposes a system of on-road vehicle trajectory collection, where an instrumented vehicle is developed with multiple horizontal 2-D lidars that have 360° coverage. The software is developed by fitting the laser points of all lidars on a vehicle model using a coupled estimation of features and reliability along frames to achieve accurate state estimations of occluded data and robust data association in multiviewpoint sensing. The performance is investigated extensively, and a large trajectory set is developed through on-road driving at the Fourth Ring Road in Beijing for a total distance of 64 km, with more than 5700 environmental trajectories with a total length of over 19 h. The performance is demonstrated to be of high quality in terms of the required properties. To the authors' knowledge, this is the first system that is able to automatically collect all-around vehicle trajectories during on-road driving and to demonstrate good performance in providing a high-quality database for driving behavior studies from an on-road perspective that addresses vehicle interactions in real-world traffic at the trajectory level.
Autors: Huijing Zhao;Chao Wang;Yuping Lin;Franck Guillemard;Stéphane Geronimi;François Aioun;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2017, volume: 18, issue:1, pages: 192 - 205
Publisher: IEEE
 
» One Mill's Experience Using MAC Testing to Evaluate Vacuum Interrupter Integrity in 15 kV Vacuum Circuit Breakers
Abstract:
For most of the first 100 years of existence of electrical power distribution systems, circuit breakers used either air- or oil-media interrupters. In the 1970s, the application of vacuum interrupter (VI) circuit breakers changed that but also left a void for how to predict remaining service life of the necessarily sealed VI. This paper reports the results of the use of alternate testing technology employing a magnetron device to apply a magnetic field, external to the VI, to enable estimation of vacuum integrity. Results are reported from one mill outage, encompassing approximately 50 VI's, which were also subjected to the mill's regular regimen of phase modulation (PM) testing for vacuum circuit breakers. The data collected are presented along with suggestions for integration of the magnetron atmospheric condition testing technology into existing circuit breaker PM efforts.
Autors: Warren Hopper;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 774 - 779
Publisher: IEEE
 
» Online Learning Control of Hydraulic Excavators Based on Echo-State Networks
Abstract:
In some of recent advances in automation of construction equipment, much research has been conducted on the control of hydraulic excavators in both industry and academia for the benefit of safety and efficiency. However, most relevant works have employed model-based control approaches that require a mathematical representation of the target plant. For hydraulic excavators, obtaining a useful dynamic model for control can be challenging due to the nonlinearity of the hydraulic servo system. With this in mind, this paper investigates the feasibility of an online learning control framework based on echo-state networks (ESNs) to the position control of hydraulic excavators. While ESNs are a class of recurrent neural networks, the training of ESNs corresponds to solving a linear regression problem, thus making it suitable for online implementation. By exploiting the dynamic properties of ESNs, the deployed control framework uses the input and output signals of the plant to learn an inverse model, which is then used to simultaneously generate control inputs to track the desired trajectory. Experiments conducted on a 21-ton class hydraulic excavator show the promising results in that accurate tracking is achieved even in the absence of a dynamic model.
Autors: Jaemann Park;Bongju Lee;Seonhyeok Kang;Pan Young Kim;H. Jin Kim;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2017, volume: 14, issue:1, pages: 249 - 259
Publisher: IEEE
 
» Online Throughput Maximization for Energy Harvesting Communication Systems with Battery Overflow
Abstract:
Energy harvesting communication system enables energy to be dynamically harvested from natural resources and stored in capacitated batteries to be used for future data transmission. In such a system, the amount of future energy to harvest is uncertain and the battery capacity is limited. As a consequence, battery overflow and energy dropping may happen, causing energy underutilization. To maximize the data throughput by using the energy efficiently, a rate-adaptive transmission schedule must address the trade-off between a high-rate transmission which avoids energy overflow and a low-rate transmission which avoids energy shortage. In this paper, we study an online throughput maximization problem without knowing future information. To the best of our knowledge, this is the first work studying the fully-online transmission rate scheduling problem for battery-capacitated energy harvesting communication systems. We consider the problem under two models of the communication channel, a static channel model that assumes the channel status is stable, and a fading channel model that assumes the channel status varies. For the former, we develop an online algorithm that approximates the offline optimal solution within a constant factor for all possible inputs. For the latter, that the channel gains vary in range , we propose an online algorithm with a proven -competitive ratio. Our simulation results further validate the efficiency of the proposed online algorithms.
Autors: Weiwei Wu;Jianping Wang;Xiumin Wang;Feng Shan;Junzhou Luo;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 185 - 197
Publisher: IEEE
 
» Open Source Solutions for Cloud Computing
Abstract:
The availability of many open source systems offers affordable opportunities for organizations to build and adopt various types of cloud computing environments.
Autors: G.R. Gangadharan;
Appeared in: Computer
Publication date: Jan 2017, volume: 50, issue:1, pages: 66 - 70
Publisher: IEEE
 
» Operating Point Optimization of Auxiliary Power Unit Using Adaptive Multi-Objective Differential Evolution Algorithm
Abstract:
Series hybrid electric vehicles improvements in fuel consumption and emissions directly depend on the operating point of the auxiliary power unit (APU). In order to balance the conflicting goals of fuel consumption and emissions reduction in the choice of operating point, the APU operating point optimization problem is formulated as a constrained multi-objective optimization problem with competing objectives of fuel-electricity conversion cost, HC emissions, CO emissions, and NOx emissions first. Then, the adaptive multi-objective differential evolution (AMODE) algorithm is proposed to solve the APU operating point multi-objective optimization problem. It adopts an external elitist archive to store the nondominated solutions that are found during the evolutionary process. The innovative adaptive mutation operator of the AMODE ensures its high searching ability, and the adaptive grids mechanism improves the diversity of the resulted Pareto solutions effectively. Finally, bench experiments under four typical driving cycles are performed and comparisons are made between the results of the proposed multi-objective optimization approach (MOA), the exponential weighted approach, and the traditional single objective approach. The experimental results show that the proposed AMODE-based MOA improves the APU emissions significantly, at the expense of a slight drop in fuel efficiency.
Autors: Yongpeng Shen;Yaonan Wang;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 115 - 124
Publisher: IEEE
 
» Operation of a Grid-Connected Lithium-Ion Battery Energy Storage System for Primary Frequency Regulation: A Battery Lifetime Perspective
Abstract:
Because of their characteristics, which have been continuously improved during the last years, Lithium-ion batteries have been proposed as an alternative viable solution to present fast-reacting conventional generating units to deliver the primary frequency regulation service. However, even though there are worldwide demonstration projects, where energy storage systems based on Lithium-ion batteries are evaluated for such applications, the field experience is still very limited. In consequence, at present, there are no very clear requirements on how the Lithium-ion battery energy storage systems should be operated, while providing frequency regulation service and how the system has to reestablish its state of charge (SOC) once the frequency event has passed. Therefore, this paper aims to investigate the effect on the lifetime of the Lithium-ion batteries energy storage system of various strategies for reestablishing the batteries’ SOC after the primary frequency regulation is successfully delivered.
Autors: Daniel-Ioan Stroe;Vaclav Knap;Maciej Swierczynski;Ana-Irina Stroe;Remus Teodorescu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 430 - 438
Publisher: IEEE
 
» Operation of a Three-Electrode Reactor With Different Electrode Bias Potential Configurations
Abstract:
The three-electrode plasma reactor for the treatment of polluted gases combines a dielectric-barrier discharge with a remote third electrode, designed to enhance streamer propagation in a relatively large region. In this paper, experimental studies of the electrical magnitudes of the discharge for different electrode bias voltage configurations are presented. Also, the Laplacian electric field distribution in the interelectrode gap is calculated for each configuration. The degradation efficiency of NO in an N2 atmosphere for the different configurations is also reported. It is found that the discharge is generated only for that electrode bias configuration for which the external electric field promotes the streamer propagation across the electrode gap. Also, for a triggered discharge, the reactor efficiency for the removal of NO changes with the different electrode bias configurations. This result can be explained in terms of the electric field intensity. The configuration with higher external electric field improves the number of streamers propagating in the interelectrode gap so that more reactive species generated in the streamers are effectively entrained in the gas flow to be treated.
Autors: J. L. Gallego;F. Minotti;D. Grondona;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2017, volume: 45, issue:1, pages: 54 - 59
Publisher: IEEE
 
» Operation of SiGe HBTs Down to 70 mK
Abstract:
We present the first measurement results of a highly scaled, 90-nm silicon–germanium heterojunction bipolar transistor (SiGe HBT) operating at cryogenic temperatures as low as 70 mK. The SiGe HBT exhibits a transistor-like behavior down to 70 mK, but below 40 K, the transconductance suggests the presence of non-equilibrium transport mechanisms. Despite the non-ideal base current at cryogenic temperatures, a current gain is achieved for nA, suggesting that ultra-low-power low-noise amplifiers should be viable. Exposure of the SiGe HBT to strong magnetic fields (±14 T) is also presented to help understand the nature of the non-ideal current.
Autors: Hanbin Ying;Brian R. Wier;Jason Dark;Nelson E. Lourenco;Luwei Ge;Anup P. Omprakash;Martin Mourigal;Dragomir Davidovic;John D. Cressler;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2017, volume: 38, issue:1, pages: 12 - 15
Publisher: IEEE
 
» Operation Process Rebuilding (OPR)-Oriented Maintenance Policy for Changeable System Structures
Abstract:
Considering the operation process rebuilding (OPR) of manufacturing/operation systems, we propose a dynamic interactive bilevel maintenance methodology to satisfy rapid market changes. Predictive maintenance (PdM) intervals at the machine level are dynamically scheduled by a multiobjective model for each diverse machine. A system-level opportunistic maintenance (OM) policy is proposed to facilitate PdM optimizations according to OPR activities. This novel OPR-OM policy utilizes a variable maintenance time window to construct optimal maintenance schedules that are suitable for changeable system structures. The results obtained by applying this methodology at Shanghai Port indicate that the proposed methodology can help a port transportation system to achieve rapid responses to OPR activities, which can significantly improve system efficiency and economy.
Autors: Tang-Bin Xia;Xin-Yang Tao;Li-Feng Xi;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2017, volume: 14, issue:1, pages: 139 - 148
Publisher: IEEE
 
» Opportunistic Routing and Scheduling for Wireless Networks
Abstract:
In spatial time division multiple access wireless mesh networks, not all links can be activated simultaneously, as links scheduled for transmission must satisfy the specified SINR requirements. Previously, slot assignment has been done on a link basis, where a set of links is selected for transmission in a given slot. However, if selected links are in deep fade or have no traffic to transmit, the slot is wasted. Thus, a node-based scheme was proposed, where a set of nodes is selected for transmission. Which link to be used by a node depends on the links’ instantaneous traffic load. Although this allows us to exploit multi-user diversity, it creates a planning discrepancy: slot assignment is designed based on long-term channel statistics, but scheduling on short-term channel fading conditions. Consequently, the performance gain of the node-based scheme is not consistent: it is marginal under certain scenarios. To avoid the design discrepancy, we develop a new slot-assignment and routing framework in this paper. The new approach incorporates short-term channel fading statistics to optimize the long term slot assignment, routing and scheduling simultaneously. Hence, multi-user diversity can be exploited more efficiently. Not only is the performance gain of the resulting system significant (can be as much as 64% higher throughput than the scheme introduced by Chen and Lea), it is also less topology dependent compared with the one by Chen and Lea.
Autors: Weiwei Chen;Chin-Tau Lea;Shiming He;Zhe XuanYuan;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 320 - 331
Publisher: IEEE
 
» Optical Detection of Ultrasound in Photoacoustic Imaging
Abstract:
Objective: Photoacoustic (PA) imaging emerges as a unique tool to study biological samples based on optical absorption contrast. In PA imaging, piezoelectric transducers are commonly used to detect laser-induced ultrasonic waves. However, they typically lack adequate broadband sensitivity at ultrasonic frequency higher than 100 MHz, whereas their bulky size and optically opaque nature cause technical difficulties in integrating PA imaging with conventional optical imaging modalities. To overcome these limitations, optical methods of ultrasound detection were developed and shown their unique applications in PA imaging. Methods: We provide an overview of recent technological advances in optical methods of ultrasound detection and their applications in PA imaging. A general theoretical framework describing sensitivity, bandwidth, and angular responses of optical ultrasound detection is also introduced. Results: Optical methods of ultrasound detection can provide improved detection angle and sensitivity over significantly extended bandwidth. In addition, its versatile variants also offer additional advantages, such as device miniaturization, optical transparency, mechanical flexibility, minimal electrical/mechanical crosstalk, and potential noncontact PA imaging. Conclusion: The optical ultrasound detection methods discussed in this review and their future evolution may play an important role in PA imaging for biomedical study and clinical diagnosis.
Autors: Biqin Dong;Cheng Sun;Hao F. Zhang;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jan 2017, volume: 64, issue:1, pages: 4 - 15
Publisher: IEEE
 
» Optical Measurement of the Dynamic Contact Process of a MEMS Inertial Switch Under High Shock Loads
Abstract:
In order to characterize the dynamic and microscopic contact process of a microelectromechanical system (MEMS) inertial switch under high shock loads, a high-speed camera-based optical measurement system was developed. The optical measurement system was successfully employed to visualize and characterize the responding motion of the proof mass and the contact process with the flexible electrodes. In particular, the contact process in a flexible and a rigid mode was compared to investigate the mechanisms of using flexible electrodes to extend the contact time. The constraint performance of the limiting post of the switch was demonstrated as well. Furthermore, the optical results were in fairly good agreement with the results of electrical measurement and numerical predictions.
Autors: Yun Cao;Zhanwen Xi;Pingxin Yu;Jiong Wang;Weirong Nie;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 701 - 709
Publisher: IEEE
 
» Optically Controlled Fast Reconfigurable Microwave Photonic Dual-Band Filter Based on Nonlinear Polarization Rotation
Abstract:
A high-speed optically controlled microwave photonic (MWP) reconfigurable dual-band filter is presented, which is achieved using a Lyot loop filter for spectrum slicing and ultrafast nonlinear polarization rotation (NPR) effect in a semiconductor optical amplifier for high-speed tuning. Through the control of optical pump power, the MWP filter is switchable between four different operation states—all-block state, dual-band state, and single-band state with two different passband frequencies. The use of NPR greatly increases the tuning speed of the MWP filter to gigahertz range, making it capable for high-speed tuning in dynamic multiband applications. The four operation states and high-speed adjustment significantly improve operation flexibility of the filter. Furthermore, good passband quality is also obtained that the sidelobe suppressions of both passbands are over 40 dB with clean and sharp passband profiles, providing good filter selectivity.
Autors: Jia Ge;Mable P. Fok;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2017, volume: 65, issue:1, pages: 253 - 259
Publisher: IEEE
 
» Optically Pumped DFB Lasers Based on GaN Using 10th-Order Laterally Coupled Surface Gratings
Abstract:
An optically pumped GaN-based laser structure with 10th-order laterally coupled surface grating is demonstrated. The fabrication involved i-line photolithography and dry etching, avoiding more complex technologies such as multiple epitaxy steps. The lasing threshold of the laterally coupled distributed-feedback (LC-DFB) laser was similar to that of a ridge waveguide Fabry–Perot (RW-FP) laser. Single-peak emission with a full width at half maximum of 0.06 nm at 404.2 nm was achieved for LC-DFB lasers. In contrast to the RW-FP lasers, the LC-DFB laser is shown to exhibit a smaller shift of the emission wavelength with temperature.
Autors: Ji Hye Kang;Martin Martens;Hans Wenzel;Veit Hoffmann;Wilfred John;Sven Einfeldt;Tim Wernicke;Michael Kneissl;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:1, pages: 138 - 141
Publisher: IEEE
 
» OptiFEX: A Framework for Exploring Area-Efficient Floating Point Expressions on FPGAs With Optimized Exponent/Mantissa Widths
Abstract:
Field-programmable gate arrays (FPGAs) could outperform microprocessors on floating point computations due to massive parallelism, freedom on the selection of exponent/mantissa width, and utilization of simplified adders and multipliers. However, optimized use of resources and accuracy of the final implemented expression are two important issues in the implementation of floating point arithmetic expressions on FPGAs. High-level optimizations such as changing the form of floating point initial expression by arithmetic rules or deciding on the exponent and mantissa widths have significant effects on the resource usage, accuracy, and efficiency of the final implementation. In this paper, we introduce an optimization framework called OptiFEX, which enables designers to optimize an initial floating point expression in terms of the resource usage and the exponent and mantissa widths based on: 1) input intervals; 2) the smallest presentable number in the implementation; and 3) the maximum permitted error interval provided by the designer. First, we come up with some techniques to generate equivalent expressions for the initial expression, and we make use of some heuristics to speed up the process of equivalent expressions’ generation. We also propose a method to estimate the mantissa width. Finally, we introduce an algorithm to choose the best expressions in terms of the resource usage based on the estimated mantissa and exponent widths.
Autors: Alireza Mahzoon;Bijan Alizadeh;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jan 2017, volume: 25, issue:1, pages: 198 - 209
Publisher: IEEE
 

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