Electrical and Electronics Engineering publications abstract of: 02-2018 sorted by title, page: 8

» Development of a TEM Compatible Nanowire Characterization Platform With Self-Forming Contacts
Abstract:
A nanowire characterization platform is designed and fabricated in MEMS-technology for the thermoelectric and structural characterization of single nanowires. The latter is achieved by making the chip compatible to TEM holder, by restricting its thickness to less than 160 μm and its diagonal dimensions to less than 3 mm. Two different fabrication technologies are presented for the realization of such platform, based on a design reproducing the functional requirements. Our first fabrication technique is based on ICP etching, using (100)-silicon wafers, and a subsequent rear grinding. However, as the design includes a vertical wall trench structures, ICP etching of such deep recesses is time-consuming and expensive. Therefore, a second fabrication process is developed, making use of wet-etched (110)-silicon. With these substrates a challenge arises from the intersection of inclined {111} facets. To solve this natural limitation, we introduce a novel fabrication process. Our technique relies on damaging the intersecting {111} planes, to make them etchable again and to produce deeper trenches with vertical walls in a wet-chemical etching process. Additionally, the electrical contacts at the platform are made from porous metal to increase the surface-to-volume ratio, to increase the possibility of a spontaneous electrical contact between the electrodes and nanowires.
Autors: S. Hoda Moosavi;Michael Kroener;Maxi Frei;Fabian Frick;Sven Kerzenmacher;Peter Woias;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Feb 2018, volume: 31, issue:1, pages: 22 - 31
Publisher: IEEE
 
» Development of High-Density Radio Frequency Plasma Sources With Very Small Diameter for Propulsion
Abstract:
Radio frequency (RF) plasma sources, especially helicon ones, are very useful in many fields, because of the high-density (up to cm−3) and low electron temperature (from a few to several electronvolts) available, using an RF frequency range. Here, we develop and characterize very small-area (from 2-cm down to 0.1–0.3 cm in diameter) RF sources that are useful for a space propulsion system with an advanced concept of an electrodeless condition (no direct contact between the plasma and electrodes), leading to a longer operation lifetime. Measurements by using electrostatic probes as well as by a spectrometer based on the collisional radiative model in a small plasma region were employed to estimate the electron density and its temperature. Here, was measured as a function of the input RF power and RF excitation frequency, especially in a higher frequency range than the usual one of ~14 MHz, under the mirror magnetic-field configuration. The electron cyclotron resonance effect in the divergent field was examined under a weaker magnetic field with the RF frequency lower than those generally employed. The particle production efficiency, even in this small source, showed an excellent performance, based on classical diffusion discussions. In addition, applying these sources were applied to a space propulsion system with the concept of the m (azimuthal mode number) = 0 half-cycle acceleration, which was operated under all electrodeless conditions in both the plasma generation and electromagnetic acceleration phases.
Autors: Shunjiro Shinohara;Daisuke Kuwahara;Takamichi Ishii;Hiraku Iwaya;Shuichi Nishimura;Tomoya Yamase;Daisuke Arai;Hirotaka Horita;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Feb 2018, volume: 46, issue:2, pages: 252 - 262
Publisher: IEEE
 
» Development of Impact Indices for Performing Charging of a Large EV Population
Abstract:
Nodal voltages and feeder currents are acquired by running load flows for electric vehicle (EV) charging purposes. The impact of the charging is analyzed by either visually inspecting the voltages and currents or calculating appropriate impact indices. Optimal charging, on the other hand, is performed by incorporating the voltages and currents in charging strategies. Though the impact indices are frequently used for assessing the impact, their usage for optimizing charging has been minimal. Therefore, this paper develops probabilistic impact indices for nodal voltage violations and feeder overloading, which can be applied not only for investigating the impact but also for optimizing charging. Also, aggregated EV load demand of a large EV population is modeled by using a new combined state of charge (SOC)-based charging strategy in time series, for assessing the applicability of the developed impact indices for practical purposes. The combined SOC dynamically integrates arrival and departure of EV and delivered energy. The numerical results show that the proposed impact indices in conjunction with the SOC-based charging have numerous advantages over the conventional charging strategies aided by the load flows.
Autors: Md Shariful Islam;Nadarajah Mithulananthan;Kwang Y. Lee;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 866 - 880
Publisher: IEEE
 
» Development of the Humanoid Disaster Response Platform DRC-HUBO+
Abstract:
This paper describes a humanoid robotics platform (DRC-HUBO+) developed for the Defense Advanced Research Projects Agency Robotics Challenge (DRC) Finals. This paper also describes the design criteria, hardware, software framework, and experimental testing of the DRC-HUBO+ platform. The purpose of DRC-HUBO+ is to perform tasks by teleoperation in hazardous environments that are unsafe for humans, such as disaster zones. We identified specific design concepts for DRC-HUBO+ to achieve this goal. For a robot to be capable of performing human tasks, a human-like shape and size, autonomy, mobility, manipulability, and power are required, among other features. Furthermore, modularized joints and a user-friendly software framework were emphasized as design concepts to facilitate research on the robot tasks. The DRC-HUBO+ platform is based on DRC-HUBO-1 and HUBO-2. The torque of each joint is increased compared to that in DRC-HUBO-1 owing to its high reduction ratio and air-cooling system. DRC-HUBO+ is designed with an exoskeletal structure to provide it with sufficient stiffness relative to its mass. All wires are enclosed within the robot body using a hollow shaft and covers to protect the wires from external shock. Regarding the vision system, active cognition of the environment can be realized using a light-detection and ranging sensor and vision cameras on the head. To achieve stable mobility, the robot can transition from the bipedal walking mode to the wheel mode using wheels located on both knees. DRC-HUBO+ has 32 degrees of freedom (DOFs), including seven DOFs for each arm and six DOFs for each leg, and a solid and light body with a height of 170 cm and a mass of 80 kg. A software framework referred to as PODO, with a Linux kernel and the Xenomai patch, is used in DRC-HUBO+.
Autors: Taejin Jung;Jeongsoo Lim;Hyoin Bae;Kang Kyu Lee;Hyun-Min Joe;Jun-Ho Oh;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 1 - 17
Publisher: IEEE
 
» Device-to-Device Networking Meets Cellular via Network Coding
Abstract:
Utilizing device-to-device (D2D) connections among mobile devices is promising to meet the increasing throughput demand over cellular links. In particular, when mobile devices are in close proximity of each other and are interested in the same content, D2D connections such as Wi-Fi Direct can be opportunistically used to construct a cooperative (and jointly operating) cellular and D2D networking system. However, it is crucial to understand, quantify, and exploit the potential of network coding for cooperating mobile devices in the joint cellular and D2D setup. In this paper, we consider this problem, and: 1) develop a network coding framework, namely NCMI, for cooperative mobile devices in the joint cellular and D2D setup, where cellular and D2D link capacities are the same; and 2) characterize the performance of the proposed network coding framework, where we use packet completion time, which is the number of transmission slots to recover all packets, as a performance metric. We demonstrate the benefits of our network coding framework through simulations.
Autors: Yasaman Keshtkarjahromi;Hulya Seferoglu;Rashid Ansari;Ashfaq Khokhar;
Appeared in: IEEE/ACM Transactions on Networking
Publication date: Feb 2018, volume: 26, issue:1, pages: 370 - 383
Publisher: IEEE
 
» DFB Laser Diodes Based on GaN Using 10th Order Laterally Coupled Surface Gratings
Abstract:
Single longitudinal mode emission of laterally coupled distributed-feedback (LC-DFB) laser diodes (LDs) based on InGaN/GaN multiquantum-well structures containing 10th-order surface Bragg gratings with V-shaped grooves is demonstrated. The gratings were fabricated alongside a 2-μm-wide contact stripe by i-line stepper lithography and inductively coupled plasma etching. A single peak emission at 404.6 nm with a fullwidth at half-maximum of 0.04 nm was achieved at an output power of about 46 mW under pulsed laser operation. The shift of the lasing wavelength of LC-DFB LDs in the temperature range from 22 °C to 45 °C was around three times smaller than that of comparable ridge waveguide Fabry-Pérot LDs.
Autors: Ji Hye Kang;Hans Wenzel;Veit Hoffmann;Erik Freier;Luca Sulmoni;Ralph-Stephan Unger;Sven Einfeldt;Tim Wernicke;Michael Kneissl;
Appeared in: IEEE Photonics Technology Letters
Publication date: Feb 2018, volume: 30, issue:3, pages: 231 - 234
Publisher: IEEE
 
» Diamond: Nesting the Data Center Network With Wireless Rings in 3-D Space
Abstract:
The introduction of wireless transmissions into the data center has shown to be promising in improving cost effectiveness of data center networks (DCNs). For high transmission flexibility and performance, a fundamental challenge is to increase the wireless availability and enable fully hybrid and seamless transmissions over both wired and wireless DCN components. Rather than limiting the number of wireless radios by the size of top-of-rack switches, we propose a novel DCN architecture, Diamond, which nests the wired DCN with radios equipped on all servers. To harvest the gain allowed by the rich reconfigurable wireless resources, we propose the low-cost deployment of scalable 3-D ring reflection spaces (RRSs) which are interconnected with streamlined wired herringbone to enable large number of concurrent wireless transmissions through high-performance multi-reflection of radio signals over metal. To increase the number of concurrent wireless transmissions within each RRS, we propose a precise reflection method to reduce the wireless interference. We build a 60-GHz-based testbed to demonstrate the function and transmission ability of our proposed architecture. We further perform extensive simulations to show the significant performance gain of diamond, in supporting up to five times higher server-to-server capacity, enabling network-wide load balancing, and ensuring high fault tolerance.
Autors: Yong Cui;Shihan Xiao;Xin Wang;Zhenjie Yang;Shenghui Yan;Chao Zhu;Xiang-Yang Li;Ning Ge;
Appeared in: IEEE/ACM Transactions on Networking
Publication date: Feb 2018, volume: 26, issue:1, pages: 145 - 160
Publisher: IEEE
 
» Differential Bandpass Filters Based on Dumbbell-Shaped Defected Ground Resonators
Abstract:
This letter presents a dumbbell-shaped defected ground resonator and its application in the design of differential filters. The operation principle of the dumbbell-shaped resonator (DSR) coupled to differential microstrip lines is studied through a circuit model analysis. The proposed circuit model is validated through the comparison with the electromagnetic simulation results. It is shown that the bandpass configuration of microstrip-line-coupled DSR can be used to design higher order bandpass filters. The design procedure is explained by developing a third-order filter prototype. The designed filter shows more than 57-dB common-mode rejection within the differential passband.
Autors: Amir Ebrahimi;Thomas Baum;Kamran Ghorbani;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Feb 2018, volume: 28, issue:2, pages: 129 - 131
Publisher: IEEE
 
» Differential Steering Based Yaw Stabilization Using ISMC for Independently Actuated Electric Vehicles
Abstract:
Differential drive assistance steering (DDAS) is an emerging assisted steering mechanism in in-wheel-motor driven (IWMD) electric vehicles, yielded by the differential moment of the front tires in the steering system. DDAS can steer the front wheels when there is no steering power from the steering motor, and thus can be used as a redundant steering mechanism. To realize the yaw control when the active front steering entirely breaks down and guarantee the transient control performance therein, this paper proposes an integral sliding mode control (ISMC) approach for IWMD electric vehicles steered by DDAS. Two contributions are made in this paper: 1) An improved disturbance observer based ISMC strategy is designed to cope with the unknown mismatched disturbances, and the composite nonlinear feedback technique is employed to design the nominal part of the controller to restrain overshoots and remove steady-state errors considering the tire force saturations; 2) An adaptive super-twisting control approach is proposed to deal with the disturbances with unknown boundaries using a continuous controller while eliminating the chattering effect. The system stability and robustness are proved via Lyapunov approach. CarSim-Simulink simulation has verified the effectiveness of the proposed control approach in the case of the steering fault.
Autors: Chuan Hu;Rongrong Wang;Fengjun Yan;Yanjun Huang;Hong Wang;Chongfeng Wei;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Feb 2018, volume: 19, issue:2, pages: 627 - 638
Publisher: IEEE
 
» Diffraction Effects and Compensation in Passive Acoustic Mapping
Abstract:
Over the last decade, a variety of noninvasive techniques have been developed to monitor therapeutic ultrasound procedures in support of safety or efficacy assessments. One class of methods employs diagnostic ultrasound arrays to sense acoustic emissions, thereby providing a means to passively detect, localize, and quantify the strength of nonlinear sources, including cavitation. Real array element diffraction patterns may differ substantially from those presumed in existing beamforming algorithms. However, diffraction compensation has received limited treatment in passive and active imaging, and measured diffraction data have yet to be used for array response correction. The objectives of this paper were to identify differences between ideal and real element diffraction patterns, and to quantify the impact of diffraction correction on cavitation mapping beamformer performance. These objectives were addressed by performing calibration measurements on a diagnostic linear array, using the results to calculate diffraction correction terms, and applying the corrections to cavitation emission data collected from soft tissue phantom experiments. Measured diffraction patterns were found to differ significantly from those of ideal element forms, particularly at higher frequencies and shorter distances from the array. Diffraction compensation of array data resulted in cavitation energy estimates elevated by as much as a factor of 5, accompanied by the elimination of a substantial bias between two established beamforming algorithms. These results illustrate the importance of using measured array responses to validate analytical field models and to minimize observation biases in imaging applications where quantitative analyses are critical for assessment of therapeutic safety and efficacy.
Autors: Michael D. Gray;Erasmia Lyka;Constantin C. Coussios;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Feb 2018, volume: 65, issue:2, pages: 258 - 268
Publisher: IEEE
 
» Digital Implementation of the Two-Compartmental Pinsky–Rinzel Pyramidal Neuron Model
Abstract:
It is believed that brain-like computing system can be achieved by the fusion of electronics and neuroscience. In this way, the optimized digital hardware implementation of neurons, primary units of nervous system, play a vital role in neuromorphic applications. Moreover, one of the main features of pyramidal neurons in cortical areas is bursting activities that has a critical role in synaptic plasticity. The Pinsky–Rinzel model is a nonlinear two-compartmental model for CA3 pyramidal cell that is widely used in neuroscience. In this paper, a modified Pinsky–Rinzel pyramidal model is proposed by replacing its complex nonlinear equations with piecewise linear approximation. Next, a digital circuit is designed for the simplified model to be able to implement on a low-cost digital hardware, such as field-programmable gate array (FPGA). Both original and proposed models are simulated in MATLAB and next digital circuit simulated in Vivado is compared to show that obtained results are in good agreement. Finally, the results of physical implementation on FPGA are also illustrated. The presented circuit advances preceding designs with regards to the ability to replicate essential characteristics of different firing responses including bursting and spiking in the compartmental model. This new circuit has various applications in neuromorphic engineering, such as developing new neuroinspired chips.
Autors: Elahe Rahimian;Soheil Zabihi;Mahmood Amiri;Bernabé Linares-Barranco;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Feb 2018, volume: 12, issue:1, pages: 47 - 57
Publisher: IEEE
 
» Digital Monopulse Beamforming for Achieving the CRLB for Angle Accuracy
Abstract:
The monopulse angle-estimation technique used in digital beamforming radars is investigated from the perspective of optimizing the angle accuracy. Specifically, a digital difference beamforming taper is proposed in this paper to optimize the monopulse angle accuracy. For a fully digitized array radar with an amplitude-tapered antenna aperture for sum beampattern with low sidelobes, the monopulse angle accuracy obtained using the proposed difference taper coincides with the Cramer–Rao lower bound. The derivation of the monopulse angle accuracy with the proposed difference taper is presented and an improvement of the accuracy over the conventional monopulse accuracy is proved theoretically. The results of computer simulations using a uniform linear array is included to highlight the accuracy improvement by a factor of 1.16 (over the conventional monopulse), which is equivalent to a 1.3 dB reduction in the signal-to-noise ratio for the requisite angle accuracy.
Autors: Ryuhei Takahashi;Takayuki Inaba;Toru Takahashi;Hirohisa Tasaki;
Appeared in: IEEE Transactions on Aerospace and Electronic Systems
Publication date: Feb 2018, volume: 54, issue:1, pages: 315 - 323
Publisher: IEEE
 
» Dimensional Synthesis of Evanescent-Mode Ridge Waveguide Bandpass Filters
Abstract:
This paper introduces a method giving dimensions of inline evanescent-mode ridge waveguide bandpass filters. Evanescent mode couplings are evaluated individually, without optimization of the entire filter. This is obtained through an improved network model of the evanescent-mode coupling, together with novel analytical formulas to correct the resonators slope parameters. Unlike prior works based on full-wave optimization of the overall structure, this method is fast and leads to accurate bandwidth results. Several filter examples are included to support the design method. A prototype filter has been manufactured and the RF measurements are in good agreement with theory.
Autors: Vittorio Tornielli di Crestvolant;Fabrizio De Paolis;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Feb 2018, volume: 66, issue:2, pages: 954 - 961
Publisher: IEEE
 
» Diophantine Equations With Binomial Coefficients and Perturbations of Symmetric Boolean Functions
Abstract:
This paper presents a study of perturbations of symmetric Boolean functions. In particular, it establishes a connection between exponential sums of these perturbations and Diophantine equations of the form , where belongs to some fixed bounded subset of . The concepts of trivially balanced symmetric Boolean function and sporadic balanced Boolean function are extended to this type of perturbations. An observation made by Canteaut and Videau for symmetric Boolean functions of fixed degree is extended. To be specific, it is proved that, excluding the trivial cases, balanced perturbations of fixed degree do not exist when the number of variables grows. Some sporadic balanced perturbations are presented. Finally, a beautiful but unexpected identity between exponential sums for perturbations of two different symmetric Boolean functions is also included in this work.
Autors: Francis N. Castro;Oscar E. González;Luis A. Medina;
Appeared in: IEEE Transactions on Information Theory
Publication date: Feb 2018, volume: 64, issue:2, pages: 1347 - 1360
Publisher: IEEE
 
» Direct Current Gas-Insulated Transmission Lines
Abstract:
The technology behind dc power transmissions shows an ever-increasing usage worldwide. Predominantly installed in remote areas, the use of overhead transmission lines is reasonable. Today, dc transmission technology is entering a new era, where rather densely populated areas are being firmly looked at with the desire of nonvisibility transmission lines. DC gas-insulated transmission lines (DC GIL) provide a powerful solution for underground installations. The acclaimed reliability of ac gas-insulated technology has, in turn, further initiated changes in the development of DC GIL. Driven by the German Energy Policy (“Energiewende”), additional north-south power transmission corridors are essential for power transmission of wind energy from the north and photovoltaic from the south, based on the required availability of energy. The DC GIL uses an aluminum conductor and enclosure pipes of high cross sections for rated currents of up to 5000 A and a voltage rating of ±550 kV. The assembly and installation technique of DC GIL is highly automated with the mobile factory and the friction stir welding process for fast and safe jointing of aluminum pipes. Development results and the state of the art are explained in this contribution.
Autors: Tomasz Magier;Michael Tenzer;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 440 - 446
Publisher: IEEE
 
» Direct Force-Reflecting Two-Layer Approach for Passive Bilateral Teleoperation With Time Delays
Abstract:
We propose a two-layer control architecture for bilateral teleoperation with communication delays. The controller is structured with an (inner) performance layer and an (outer) passivity layer. In the performance layer, any traditional controller for bilateral teleoperation can be implemented. The passivity layer guarantees that, from the operator and environment perspective, the overall teleoperator is passive: The amount of energy that can be extracted from the teleoperator is bounded from below and the rate of increase of the stored energy in the teleoperator is bounded by (twice) the environment and operator supplied power. Passivity is ensured by modulating the performance layer outputs and by injecting a variable amount of damping via an energy-based logic that follows the innovative principle of energy duplication and takes into account the detrimental effects of time delays. In contrast to the traditional teleoperation approach, in which the master and slave controllers implement an as-stiff-as-possible coupling between the master and slave devices, our scheme is specifically designed for direct force-reflecting bilateral teleoperation: The slave controller mimics the operator action, whereas the master controller reflects the slave-environment interaction. We illustrate the performance of the two-layer approach in a challenging experiment with a round-trip communication delay of 300 ms while making and breaking contact with a stiff aluminum environment. Finally, we also compare our controller with the state of the art.
Autors: Dennis Heck;Alessandro Saccon;Ruud Beerens;Henk Nijmeijer;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 194 - 206
Publisher: IEEE
 
» Directional Bending Sensor Based on a Dual Side-Hole Fiber Mach–Zehnder Interferometer
Abstract:
A new directional bending sensor based on a dual side-hole fiber (DSHF) that can detect both the direction and magnitude of bending in a self-temperature compensated manner is described and experimentally demonstrated. The sensor is based on an in-fiber Mach–Zehnder interferometer (MZI), where a DSHF segment was spliced between two standard single-mode fibers (SMFs) as input and output. The sensor has two orthogonal axes which are formed by both the asymmetry in the side-hole location in DSHF and an offset in the fusion splice between the SMF and DSHF. The visibility in the MZI output intensity and the spectral shifts of MZI fringes show separate responses to the bending curvature and direction, which is a key feature of the directional curvature sensor. An inscribed fiber Bragg grating in the DSHF measure allows the temperature to be measured independently. The sensor can provide salient advantages in its unique capability to precisely quantify the direction and magnitude of bending along with its reproducibility, compactness, and suitability for mass production, which makes it suitable for many practical bending sensing applications.
Autors: Ye Tian;Quan Chai;Tao Tan;Boxin Mu;Qiang Liu;Yanlei Liu;Jing Ren;Jianzhong Zhang;Kyunghwan Oh;Elfed Lewis;Jun Yang;Zhihai Liu;Wenping Zhang;Libo Yuan;
Appeared in: IEEE Photonics Technology Letters
Publication date: Feb 2018, volume: 30, issue:4, pages: 375 - 378
Publisher: IEEE
 
» Discovering Triangles in Portraits for Supporting Photographic Creation
Abstract:
Incorporating the concept of triangles in photos is an effective composition technique used by professional photographers for making pictures more interesting or dynamic. Information on the locations of the embedded triangles is valuable for comparing the composition of portrait photos which can be further leveraged by a retrieval system or used by the photographers. This paper presents a system to automatically detect embedded triangles in portrait photos. The problem is challenging because the triangles used in portraits are often not clearly defined by straight lines. The system first extracts a set of filtered line segments as candidate triangle sides and then utilizes a modified random sample consensus algorithm to fit triangles onto the set of line segments. We propose two metrics Continuity Ratio and Total Ratio to evaluate the fitted triangles; those with high fitting scores are taken as detected triangles. Experimental results have demonstrated high accuracy in locating preeminent triangles in portraits without dependence on the camera or lens parameters. To demonstrate the benefits of our method to digital photography we have developed two novel applications that aim to help users compose high-quality photos. In the first application we develop a human position and pose recommendation system by retrieving and presenting compositionally similar photos taken by competent photographers. The second application is a novel sketch-based triangle retrieval system which searches for photos containing a specific triangular configuration. User studies have been conducted to validate the effectiveness of these approaches.
Autors: Siqiong He;Zihan Zhou;Farshid Farhat;James Z. Wang;
Appeared in: IEEE Transactions on Multimedia
Publication date: Feb 2018, volume: 20, issue:2, pages: 496 - 508
Publisher: IEEE
 
» Discrete-Time Positive Edge-Consensus for Undirected and Directed Nodal Networks
Abstract:
This brief addresses the positive consensus of the edges with multi-input and multi-output positive dynamics for undirected and directed networks. The line graph is derived from the given nodal graph to represent the interaction of the edges, and the discrete-time positive systems are introduced to describe the edge dynamics. Based on the positive system theory and consensus analysis, a necessary and sufficient condition for positive edge-consensus is established, which reveals how the edge dynamics and the eigenvalues of the Perron matrix of line graph affect the consensus. Moreover, with further analysis, sufficient conditions for positive edge-consensus are derived without using the global interaction topology. It shows that the positive consensus can be achieved with the combined effect of edge dynamics, the number of edges, and the minimum diagonal element of the Perron matrix of line graph. The feedback matrix can be computed by solving linear programming problem. Finally, the simulations explicitly verify the proposed theoretical results.
Autors: Han Wu;Housheng Su;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Feb 2018, volume: 65, issue:2, pages: 221 - 225
Publisher: IEEE
 
» Discrete-Time Predictor Feedback for Consensus of Multiagent Systems With Delays
Abstract:
This note develops a discrete-time predictor feedback control scheme for continuous-time multiagent systems with input and communication time delays. With measurement of locally available relative state signals among neighbored agents, the controller is able to achieve consensus for a large variety of linear open-loop agent dynamics, including exponentially unstable systems. Moreover, the new design can deal with arbitrarily large time delays in some special scenarios. The feature of discrete-time and relative state measurement substantially saves implementation cost compared with the existing methods in the literature. Numerical simulation demonstrates the effectiveness of the proposed theoretical design.
Autors: Anton Ponomarev;Zhiyong Chen;Hai-Tao Zhang;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Feb 2018, volume: 63, issue:2, pages: 498 - 504
Publisher: IEEE
 
» Displacement Measurement Using Two-Photon Absorption Process in Si-Avalanche Photodiode and Fiber Bragg Gratings
Abstract:
This paper proposes a displacement measurement system using two-photon absorption (TPA) process in a Si-avalanche photodiode and fiber Bragg gratings (FBGs). The use of TPA process eliminates high-frequency and complicated RF circuits usually required for intensity correlation measurements. By controlling the phase difference between the modulation signals for probe and reference light, the displacements of FBGs are precisely measured. Small displacement of an FBG by 0.4 mm was successfully measured in the proof-of-concept experiment.
Autors: Yosuke Tanaka;Masaya Nemoto;Yoshiki Yamada;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2018, volume: 36, issue:4, pages: 1192 - 1196
Publisher: IEEE
 
» Disseminating Multilayer Multimedia Content Over Challenged Networks
Abstract:
Mobile devices are getting increasingly popular all over the world. Mobile users in developing countries however rarely have Internet access which puts them at economic and social disadvantages compared to their counterparts in developed countries. We propose mBridge: A distributed system to disseminate multimedia content to mobile users with intermittent Internet access and opportunistic ad hoc connectivity. By disseminating various multimedia content such as news reports notification messages targeted advertisements movie trailers and TV shows mBridge aims to eliminate the digital divide. We formulate an optimization problem to compute personalized distribution plans for individual mobile users to maximize the overall user experience under various resource constraints. Our formulation jointly considers the characteristics of multimedia content mobile users and intermittent networks. We present an efficient distribution planning algorithm to solve our problem and we develop several online heuristics to adapt to the system and network dynamics. We implement a prototype system and demonstrate that our algorithm outperforms the existing algorithms by up to 206% 472% and 188% in terms of user experience disk efficiency and energy efficiency respectively. In addition we conduct trace-driven simulations to rigorously evaluate the proposed system in different environments and for large-scale deployments. Our simulation results demonstrate that the proposed algorithm substantially outperforms the closest ones in the literature in all performance measures. We believe that mBridge can allow multimedia content providers to reach out to more mobile users and mobile users to access multimedia content without always-on Internet access.
Autors: Hua-Jun Hong;Tarek El-Ganainy;Cheng-Hsin Hsu;Khaled A. Harras;Mohamed Hefeeda;
Appeared in: IEEE Transactions on Multimedia
Publication date: Feb 2018, volume: 20, issue:2, pages: 345 - 360
Publisher: IEEE
 
» Distributed Active State Estimation With User-Specified Accuracy
Abstract:
In this paper, we address the problem of controlling a network of mobile sensors so that a set of hidden states are estimated up to a user-specified accuracy. The sensors take measurements and fuse them online using an information consensus filter (ICF). At the same time, the local estimates guide the sensors to their next best configuration. This leads to an LMI-constrained optimization problem that we solve by means of a new distributed random approximate projections method. The new method is robust to the state disagreement errors that exist among the robots as the ICF fuses the collected measurements. Assuming that the noise corrupting the measurements is zero-mean and Gaussian and that the robots are self-localized in the environment, the integrated system converges to the next best positions from where new observations will be taken. This process is repeated with the robots taking a sequence of observations until the hidden states are estimated up to the desired user-specified accuracy. We present simulations of sparse landmark localization, where the robotic team achieves the desired estimation tolerances while exhibiting interesting emergent behavior.
Autors: Charles Freundlich;Soomin Lee;Michael M. Zavlanos;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Feb 2018, volume: 63, issue:2, pages: 418 - 433
Publisher: IEEE
 
» Distributed Caching Based on Matching Game in LEO Satellite Constellation Networks
Abstract:
With the rapid development of low Earth orbit (LEO) constellation satellite networks and on-board processing, in-network content caching becomes feasible, which can further improve the system performance. In order to minimize user terminals content access delay, a novel caching algorithm by optimizing content placement in LEO satellite constellation networks is proposed in this letter. The formulated problem is proved to be NP-complete (NPC) by reducing it to the 2-disjoint set cover problem, which is a known NPC problem. This letter considers the interactions among distributed satellites for making individual content decisions. Then, this letter adopts an exchange-stable matching (ESM) algorithm based on many-to-many matching game with externalities. Simulation results show that the ESM algorithm can improve the system performance in terms of content access delay.
Autors: Shuaijun Liu;Xin Hu;Yipeng Wang;Gaofeng Cui;Weidong Wang;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 300 - 303
Publisher: IEEE
 
» Distributed Clustering-Task Scheduling for Wireless Sensor Networks Using Dynamic Hyper Round Policy
Abstract:
Prolonging the network life cycle is an essential requirement for many types of Wireless Sensor Network (WSN) applications. Dynamic clustering of sensors into groups is a popular strategy to maximize the network lifetime and increase scalability. In this strategy, to achieve the sensor nodes’ load balancing, with the aim of prolonging lifetime, network operations are split into rounds, i.e., fixed time intervals. Clusters are configured for the current round and reconfigured for the next round so that the costly role of the cluster head is rotated among the network nodes, i.e., Round-Based Policy (RBP). This load balancing approach potentially extends the network lifetime. However, the imposed overhead, due to the clustering in every round, wastes network energy resources. This paper proposes a distributed energy-efficient scheme to cluster a WSN, i.e., Dynamic Hyper Round Policy (DHRP), which schedules clustering-task to extend the network lifetime and reduce energy consumption. Although DHRP is applicable to any data gathering protocols that value energy efficiency, a Simple Energy-efficient Data Collecting (SEDC) protocol is also presented to evaluate the usefulness of DHRP and calculate the end-to-end energy consumption. Experimental results demonstrate that SEDC with DHRP is more effective than two well-known clustering protocols, HEED and M-LEACH, for prolonging the network lifetime and achieving energy conservation.
Autors: Peyman Neamatollahi;Mahmoud Naghibzadeh;Saeid Abrishami;Mohammad-Hossein Yaghmaee;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Feb 2018, volume: 17, issue:2, pages: 334 - 347
Publisher: IEEE
 
» Distributed Computation of Equilibria in Misspecified Convex Stochastic Nash Games
Abstract:
The distributed computation of Nash equilibria is assuming growing relevance in engineering where such problems emerge in the context of distributed control. Accordingly, we present schemes for computing equilibria of two classes of static stochastic convex games complicated by a parametric misspecification, a natural concern in the control of large-scale networked engineered system. In both schemes, players learn the equilibrium strategy while resolving the misspecification: 1) Monotone stochastic Nash games: We present a set of coupled stochastic approximation schemes distributed across agents in which the first scheme updates each agent's strategy via a projected (stochastic) gradient step, whereas the second scheme updates every agent's belief regarding its misspecified parameter using an independently specified learning problem. We proceed to show that the produced sequences converge in an almost sure sense to the true equilibrium strategy and the true parameter, respectively. Surprisingly, convergence in the equilibrium strategy achieves the optimal rate of convergence in a mean-squared sense with a quantifiable degradation in the rate constant; 2) Stochastic Nash–Cournot games with unobservable aggregate output: We refine 1) to a Cournot setting where we assume that the tuple of strategies is unobservable while payoff functions and strategy sets are public knowledge through a common knowledge assumption. By utilizing observations of noise-corrupted prices, iterative fixed-point schemes are developed, allowing for simultaneously learning the equilibrium strategies and the misspecified parameter in an almost sure sense.
Autors: Hao Jiang;Uday V. Shanbhag;Sean P. Meyn;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Feb 2018, volume: 63, issue:2, pages: 360 - 371
Publisher: IEEE
 
» Distributed ECM Algorithm for OTHR Multipath Target Tracking With Unknown Ionospheric Heights
Abstract:
Over-the-horizon radar (OTHR) target tracking in the presence of complicated ionospheric environment mainly faces three challenges, i.e., discrete uncertainty of multipath data association, continuous uncertainty of ionospheric heights, and coupling of target state estimation and ionospheric parameters identification. The existing OTHR target tracking algorithms demanded that the ionospheric heights should be exactly known or statistical properties known. However, the ionospheric heights is inaccurate due to the inherent variability of ionosphere, especially when the deployment of ionosondes is unavailable in the sea area or hostile zone. This paper introduces a joint optimization scheme called distributed expectation-conditional maximization (DECM), which solves the target state estimation, multipath data association, and ionospheric heights identification simultaneously. The proposed DECM algorithm consists of a local estimation level and a global fusion level, whereas information is exchanged within these two levels until iteration terminates. This dual-level processing framework transforms the high-dimensional estimation problems into several low-dimensional parallel path-dependent estimation problems, which improves the computational efficiency of expectation maximization under high-dimensional latent variables case. In addition, the closed-loop structure is beneficial to the coupling problem. The simulation indicates the effectiveness of the proposed scheme.
Autors: Hua Lan;Yan Liang;Zengfu Wang;Feng Yang;Quan Pan;
Appeared in: IEEE Journal of Selected Topics in Signal Processing
Publication date: Feb 2018, volume: 12, issue:1, pages: 61 - 75
Publisher: IEEE
 
» Distributed Event Localization via Alternating Direction Method of Multipliers
Abstract:
This paper addresses the problem of distributed event localization using noisy range measurements with respect to sensors with known positions. Event localization is fundamental in many wireless sensor network applications such as homeland security, law enforcement, and environmental studies. However, most existing distributed algorithms require the target event to be within the convex hull of the deployed sensors. Based on the alternating direction method of multipliers (ADMM), we propose two scalable distributed algorithms named GS-ADMM and J-ADMM which do not require the target event to be within the convex hull of the deployed sensors. More specifically, the two algorithms can be implemented in a scenario in which the entire sensor network is divided into several clusters with cluster heads collecting measurements within each cluster and exchanging intermediate computation information to achieve localization consistency (consensus) across all clusters. This scenario is important in many applications such as homeland security and law enforcement. Simulation results confirm effectiveness of the proposed algorithms.
Autors: Chunlei Zhang;Yongqiang Wang;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Feb 2018, volume: 17, issue:2, pages: 348 - 361
Publisher: IEEE
 
» Distributed LQR Consensus Control for Heterogeneous Multiagent Systems: Theory and Experiments
Abstract:
Controlling heterogeneous multiagent systems (MASs) to cooperatively accomplish tasks is currently an emerging topic in the application-oriented research of robotics. This paper investigates the consensus problem of a MAS consisting of quadrotors and two-wheeled mobile robots (2WMRs). Directed and switching interaction topologies over the network are considered. We propose a distributed linear quadratic regulation (LQR) consensus protocol for the quadrotors and design an LQR-based Rotate&Run Consensus Scheme for the 2WMRs to update the states. We use the algebraic graph theory and stochastic matrix analysis to conduct the convergence analysis of consensus. The underactuation characteristic of the 2WMR dynamics is considered in the controller design. The effectiveness of the control methods is verified by simulations and experiments.
Autors: Bingxian Mu;Yang Shi;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Feb 2018, volume: 23, issue:1, pages: 434 - 443
Publisher: IEEE
 
» Distributed Privacy-Aware Fast Selection Algorithm for Large-Scale Data
Abstract:
Finding the smallest/largest element of a large array, i.e., -selection is a fundamental supporting algorithm in data analysis. Due to the fact that big data born in geo-distributed environments, it especially requires communication-efficient distributed -selection, besides typical computation and memory efficiency. Moreover, sensitive organizations make data privacy a rigorous precondition for their participation in such distributed statistical analysis for common profit. To this end, we propose a Distributed Privacy-Aware Median (DPAM) selection algorithm for median selection in distributed large-scale data while preserving local statistics privacy, and extend it to arbitrary -selection. DPAM utilizes mean to approximate median, via contraction of the standard deviation. It is the theoretical fastest with a worst computation complexity of , and also highly efficient in communication overhead (in logarithm of data range). To preserve -differential privacy of local statistics, DPAM randomly adds dummy eleme- ts (the number follows a rounded Laplacian distribution) to local data. The noise does not degrade the estimation precision or convergence rate. Performance of DPAM is compared with centralized/distributed quick select and optimization, in terms of complexity and privacy preserving ability. Extensive simulation and experiment results show the higher efficiency of DPAM.
Autors: Hao Liu;Jiming Chen;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Feb 2018, volume: 29, issue:2, pages: 365 - 376
Publisher: IEEE
 
» Distributed Resource Allocation for D2D Communications Underlaying Cellular Networks in Time-Varying Environment
Abstract:
In this letter, we address joint channel and power allocation in a device-to-device (D2D) network underlaying a cellular network in a time-varying environment. A fully distributed solution, which does not require information exchange, is proposed to allocate channel and power levels to D2D pairs while ensuring the quality of service (QoS) of the cellular user equipments (CUEs). The problem is modeled as a Stackelberg game with pricing. At the leader level, base station sets prices for the channels to ensure the QoS of the CUEs. At the follower level, D2D pairs use an uncoupled stochastic learning algorithm to learn the channel indices and power levels while minimizing the weighted aggregate interference and the price paid. The follower game is shown to be an ordinal potential game. We perform simulations to study the convergence of the algorithm.
Autors: Susan Dominic;Lillykutty Jacob;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 388 - 391
Publisher: IEEE
 
» Distributed Resource Allocation in SDCN-Based Heterogeneous Networks Utilizing Licensed and Unlicensed Bands
Abstract:
The explosive growth of mobile data traffic and the scarcity of available licensed spectrum make resource allocation in heterogeneous networks a critical issue. A distributed resource allocation algorithm for software defined cellular networks for future 5G networks is proposed. The adoption of integrated femto-WiFi small cells is used to alleviate spectrum shortage, by permitting simultaneous access to both the licensed bands (via cellular interface) and unlicensed bands (via WiFi interface). A weighted utility maximization problem is formulated to optimize resource allocation, utilizing the software defined network controller’s global view. A fully distributed solution based on the weighted utility maximization optimizes resource allocation, keeping the interference from small cells to macrocells below predefined thresholds. The proposed algorithm considers the sDevices, which have both cellular and WiFi interfaces, and the wDevices which have WiFi-only interfaces. Numerical simulations substantiate the superiority of the proposed resource allocation algorithm, which increases significantly the average throughput and average utility of all devices, compared with the traditional and current methods. Throughput gains as large as 41.6% in spectral efficiency for the average of all sDevices and wDevices are achieved by the new designs.
Autors: Chunyu Pan;Changchuan Yin;Norman C. Beaulieu;Jian Yu;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 711 - 721
Publisher: IEEE
 
» Distributed Scheduling in Multiple Access With Bursty Arrivals Under a Maximum Delay Constraint
Abstract:
A time-slotted multiple access system with bursty data arrivals to the terminals is considered, where variable sized packets independently arrive in each slot at every transmitter. Each packet is required to be delivered to a common receiver within a certain number of slots specified by a maximum delay constraint. The terminals know only their own packet arrival process, i.e., the arrivals at the rest of the terminals are unknown to each transmitter, except for their probability distributions. For this interesting distributed multiple access model, we design novel online communication schemes which transport the arriving data without any outage, while respecting the delay constraint. In particular, the users choose their respective transmit powers in a distributed manner, ensuring at the same time that the joint power vector is sufficient to support the distributed choice of data rates employed in that slot. The proposed schemes are not only optimal in minimizing the average transmit sum power, but they also considerably outperform conventional orthogonal multiple access techniques like time-division multiple access. An optimal scheme for a multiple access channel with arrivals and time-varying fading is also presented, under a unit slot delay constraint.
Autors: Sakshi Kapoor;Sreejith Sreekumar;Sibi Raj B. Pillai;
Appeared in: IEEE Transactions on Information Theory
Publication date: Feb 2018, volume: 64, issue:2, pages: 1297 - 1316
Publisher: IEEE
 
» Distributed TOA-Based Positioning in Wireless Sensor Networks: A Potential Game Approach
Abstract:
In this letter, we solve the problem of positioning based on the time-of-arrival technique in wireless sensor networks. Different from the traditional estimation methods, the position of a target node is considered as a strategy of anchor nodes, and the cognition information is introduced to enrich positional information. After proposing the concept of consensus of cognition and consensus of measurements, we re-investigate the positioning problem from a game-theoretic perspective. It is proved that the proposed game is an exact potential game, which exhibits attractive properties about the Nash equilibrium (NE). Then, the best response algorithm is used to achieve the NE point. The simulation results indicate that the performance of positioning with a suitable tradeoff parameter is better than the performance of recursive least-squares algorithm in terms of positional accuracy and convergence rate.
Autors: Mingxing Ke;Yuhua Xu;Alagan Anpalagan;Dianxiong Liu;Yuli Zhang;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 316 - 319
Publisher: IEEE
 
» Distributed Uplink Reception in Cloud Radio Access Networks: A Linear Coding Approach
Abstract:
This paper considers an uplink cloud radio access network (C-RAN), in which antenna terminals (ATs) are connected to a central process (CP) via digital error-free links of a finite-capacity , and serves user terminals. In this network, novel low-complexity detection methods at the CP are proposed by incorporating a lattice-quantize-and-forward (LQF) framework, which converts the C-RAN into an equivalent finite-field multiple-input-multiple-output (FF-MIMO) channel. In particular, under this equivalent FF single-input-multiple-output channel, an optimal receive combining method is presented by using a simple repetition code. In addition, using linear block codes, a low-complexity detection method is presented for the equivalent FF-MIMO channel. Finally, by simulations, it is demonstrated that the proposed detection method combined with the LQF framework provides high achievable sum rates for uplink C-RANs especially when a lot of low-cost ATs are deployed.
Autors: Song-Nam Hong;Yo-Seb Jeon;Namyoon Lee;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1470 - 1481
Publisher: IEEE
 
» DIY for Engineers [MicroBusiness]
Abstract:
DIY is the abbreviation for “do it yourself.” I recently had a friend comment to me, “You do everything yourself.” That's not really true, but it's in my nature to want to do things myself. I suspect it's that way for many engineers; we chose engineering because we like to make things.
Autors: Fred Schindler;
Appeared in: IEEE Microwave Magazine
Publication date: Feb 2018, volume: 19, issue:1, pages: 14 - 16
Publisher: IEEE
 
» Double-Differential-Fed, Dual-Polarized Patch Antenna With 90 dB Interport RF Isolation for a 2.4 GHz In-Band Full-Duplex Transceiver
Abstract:
This letter presents a 2.4 GHz, dual-polarized microstrip patch antenna with extremely high interport isolation for a shared antenna architecture-based in-band full-duplex transceiver. The presented antenna configuration is based on four-ports linearly polarized single radiating element with differential feeding for both transmit and receive operation. The double-differential feeding using two identical 3 dB/180° ring hybrid couplers with nice amplitude and phase balance effectively suppresses the interport RF leakage to achieve very high isolation. The prototype of the proposed antenna architecture is implemented using a 1.6 mm thick general-purpose FR-4 substrate. The implemented antenna provides more than 90 and 80 dB interport RF isolation for 20 and 40 MHz bandwidths, respectively, in addition to more than 98 dB port-to-port peak isolation when measured inside an anechoic chamber. To the best of our knowledge, this is the highest amount of RF isolation reported for a single dual-polarized patch antenna.
Autors: Haq Nawaz;Ibrahim Tekin;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 287 - 290
Publisher: IEEE
 
» Double-Directional Dual-Polarimetric Cluster-Based Characterization of 70–77 GHz Indoor Channels
Abstract:
This paper presents 70–77 GHz wideband channel characteristics of delay, spatial, and polarimetric domains for small office and entrance hall scenarios. Based on measured multidimensional power spectra of delay, and directions (i.e., azimuth and elevation) of departure and of arrival, multipath clusters were detected using the K-means, threshold-based, and Gaussian-mixture-model clustering algorithms. The spatial positions and directions of clusters, including the first- and last-hop scatterers, are determined using a measurement-based ray tracer method. Our experimental analysis reveals that the composite and cluster-level channel behaviors are considerably dependent on the geometry of environments, the interaction/bouncing order between a wave and objects, the position of transmitter and receiver, the underlying antenna type, and the polarimetric combination. The angular spread of arrival is observed larger than that of departure, and the characteristics for the horizontal polarization are comparable with those for vertical polarization. Our results also manifest the merits of threshold-based clustering algorithm in terms of clusters’ compactness, separation, and exclusiveness. We further find that the identified interaction points exhibit excellent agreement with real physical objects existing in the environment. Based on these results, an indoor stochastic channel model is established not only for the composite parameters and cluster characteristics, but also for the first- and last-hop scatterers’ position, direction, and their dispersive statistics. This model can be used to generate channel realizations of reasonable spatial consistency.
Autors: Cen Ling;Xuefeng Yin;Robert Müller;Stephan Häfner;Diego Dupleich;Christian Schneider;Jian Luo;Hua Yan;Reiner Thomä;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 857 - 870
Publisher: IEEE
 
» Downlink Resource Allocation Under Time-Varying Interference: Fairness and Throughput Optimality
Abstract:
We address the problem of downlink resource allocation in the presence of time-varying interference. We consider a scenario where users served by a base station face interference from a neighboring base station. We model the interference from the neighboring base station as an ON/OFF renewal process, that arises due to its idle and busy cycles. The users feedback their downlink signal to interference plus noise ratio (SINR) values to their base station, but these values are outdated. In this setting, we characterize how the resource allocation layer can optimally exploit the reported SINR values, which could be unreliable due to time-varying interference. In particular, we propose resource allocation policies in two well-known paradigms. First, we address the problem of –fair scheduling, and propose a policy that ensures asymptotic convergence to the optimal –fair throughput. Second, we propose a throughput optimal resource allocation policy, i.e., a policy that can stably support the largest possible set of traffic rates under the interference scenario considered. Estimating the outage probability from the outdated SINR values plays an important role in both scheduling paradigms, and we accomplish this using tool from renewal theory.
Autors: Ravi Kiran Raman;Krishna Jagannathan;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 722 - 735
Publisher: IEEE
 
» Downlink Spectral Efficiency of Distributed Massive MIMO Systems With Linear Beamforming Under Pilot Contamination
Abstract:
In this paper, the downlink spectral efficiency of multicell multiuser distributed massive MIMO systems with linear beamforming is studied in the presence of pilot contamination. According to the levels of effective channel gain information at user side, we provide the lower bound and upper bound on user ergodic achievable downlink rate. Due to the different access distance from each user to different remote antenna units, the entries of user channel vectors are no longer identically distributed in distributed massive MIMO systems, which makes the spectral efficiency analysis challenging. Using the properties of Gamma distributions together with the approximate methods for nonisotropic vectors, we derive tractable, but accurate closed-form expressions for the rate bounds with maximum ratio transmission (MRT) and zero-forcing (ZF) beamforming in distributed massive MIMO systems. Based on these expressions, user ultimate achievable rates are also given when the ratio of the total number of transmit antennas to the number of users goes to infinity. It is shown that MRT and ZF beamforming achieve the same ultimate rate no matter what levels of effective channel gain information at user side. Numerical results show that ZF achieves better performance gain and faster convergence speed than MRT. When the coherence interval is large, the downlink beamforming training scheme is more preferable for the distributed massive MIMO systems.
Autors: Jiamin Li;Dongming Wang;Pengcheng Zhu;Jiangzhou Wang;Xiaohu You;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1130 - 1145
Publisher: IEEE
 
» DPSAF: Forward Prediction Based Dynamic Packet Scheduling and Adjusting With Feedback for Multipath TCP in Lossy Heterogeneous Networks
Abstract:
As multihomed terminals are equipped with multiple interfaces and allowed to access heterogeneous networks, transferring data simultaneously through all the available paths becomes possible and also brings many benefits. Multipath TCP (MPTCP) has been proposed to distribute an application stream over different TCP connections. However, due to the disparate latencies of different paths, the problem of existing out-of-order packets usually occurs at the receiver. Large number of these packets exhaust the limited receiving buffer and make the receive window be stalled, which greatly degrade the throughput. Thus, an efficient scheduling mechanism will play an important role to keep in-order delivery. However, almost all of the previous intelligent scheduling mechanisms ignored packet losses, and didn't consider window changes of the congestion control algorithm and utilize the feedback information, which cannot perform well in the lossy heterogeneous networks. In this paper we propose a new scheduling algorithm: Forward Prediction based Dynamic Packet Scheduling and Adjusting with Feedback (DPSAF). DPSAF first utilizes maximum likelihood estimation in TCP modeling to estimate the data amount sent on other paths simultaneously, which takes packet loss rate and time offset into consideration, then gets feedback information from SACK options and fixes the scheduling value. From the simulation, we can see that our mechanism obviously improves throughput and reduces cache occupancy at receiver in lossy heterogeneous networks.
Autors: Kaiping Xue;Jiangping Han;Dan Ni;Wenjia Wei;Ying Cai;Qing Xu;Peilin Hong;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1521 - 1534
Publisher: IEEE
 
» DropBand: A Simple and Effective Method for Promoting the Scene Classification Accuracy of Convolutional Neural Networks for VHR Remote Sensing Imagery
Abstract:
The dropout and data augmentation techniques are widely used to prevent a convolutional neural network (CNN) from overfitting. However, the dropout technique does not work well when applied to the input channels of neural networks, and data augmentation is usually employed along the image plane. In this letter, we present DropBand, which is a simple and effective method of promoting the classification accuracy of CNNs for very-high-resolution remote sensing image scenes. In DropBand, more training samples are generated by dropping certain spectral bands out of original images. Furthermore, all samples with the same set of spectral bands are collected together to train a base CNN. The final prediction for a test sample is represented by the combination of outputs of all base CNNs. The experimental results for three publicly available data sets, i.e., the SAT-4, SAT-6, and UC-Merced image data sets, show that DropBand can significantly improve the classification accuracy of a CNN.
Autors: Naisen Yang;Hong Tang;Hongquan Sun;Xin Yang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Feb 2018, volume: 15, issue:2, pages: 257 - 261
Publisher: IEEE
 
» DSIP: A Scalable Inference Accelerator for Convolutional Neural Networks
Abstract:
This paper presents a scalable inference accelerator called a deep-learning specific instruction-set processor (DSIP) to support various convolutional neural networks (CNNs). For CNNs requiring a large amount of computations and memory accesses, a programmable inference system called master–slave instruction set architecture (ISA) is newly proposed to achieve high flexibility, processing speed, and energy efficiency. The master is responsible for sending and receiving feature maps in order to deal with neural networks in a scalable way, and the slave performs CNN operations, such as multiply accumulate, max pooling, and activation functions, on the features received from the master. The master–slave ISA maximizes computation speed by overlapping the off-chip data transmission and the CNN operations, and reduces power consumption by performing the convolution incrementally to reuse input and partial-sum data as maximally as possible. An inference system can be configured by connecting multiple DSIPs in a form of either 1-D or 2-D chain structure in order to enhance computation speed further. To evaluate the proposed accelerator, a prototype chip is implemented and evaluated for AlexNet. Compared to the state-of-the-art accelerator, the DSIP-based system enhances the energy efficiency by 2.17.
Autors: Jihyuck Jo;Soyoung Cha;Dayoung Rho;In-Cheol Park;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2018, volume: 53, issue:2, pages: 605 - 618
Publisher: IEEE
 
» Dual Compressed Sensing Method for Solving Electromagnetic Scattering Problems by Method of Moments
Abstract:
Rapid and accurate calculation of electromagnetic scattering problems over a wide incident angle range is a difficult but valuable subject in computational electromagnetics (CEM). Traditional methods need to calculate repeatedly at each finer angle step, which leads to low efficiency. Based on the recently proposed compressed sensing (CS) method in CEM, a new scheme is proposed to further improve the computation efficiency, in which CS is used two times to form an undetermined equation model and incident sources including much information of incident angles simultaneously. Theoretical frame and specific formulas are derived in detail, and numerical results verify that it provides an efficient technical route for solving electromagnetic scattering problems.
Autors: Xinyuan Cao;Mingsheng Chen;Xianliang Wu;Meng Kong;Jinhua Hu;Yanyan Zhu;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 267 - 270
Publisher: IEEE
 
» Dual of Defected Ground Structure for Coplanar Stripline
Abstract:
Defected ground structures (DGS) have been used with microstrip and coplanar waveguide (CPW), but until now no comparable structure has been demonstrated for coplanar stripline (CPS), probably because there is no “ground plane.” This letter introduces a dual of DGS for CPS with dual properties, or it acts as a shunt, series RLC circuit that creates an equivalent shunt short circuit at the resonant frequency, which is the dual of the DGS in microstrip or CPW.
Autors: George E. Ponchak;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Feb 2018, volume: 28, issue:2, pages: 105 - 107
Publisher: IEEE
 
» Dual-Band and Low-Profile Differentially Fed Slot Antenna for Wide-Angle Scanning Phased Array
Abstract:
A novel dual-band slot antenna with low profile is proposed. The slot antenna is constructed on dual-layer substrates, in which a metal cavity is fabricated by metalized vias. The antenna is fed by a differential scheme, so it can be easily integrated with other systems. The proposed antenna can operate at dual resonant frequencies because of the metal cavity and the radiating slot. A corresponding differential feeding network is constructed on another substrate. The half-power beamwidth of the slot antenna's radiation pattern is wide in the electric plane ( E-plane), and it is suitable to be applied to wide-angle scanning phased arrays. The phased array built by the slot antenna can realize wide-angle scanning within 3 dB peak gain fluctuation in the E -plane at both frequencies. Measured results show that the phased array can scan from –67° to 69° at 5.02 GHz and from –62° to 64° at 5.58 GHz.
Autors: Jiajia Guo;Shaoqiu Xiao;Shaowei Liao;Bingzhong Wang;Quan Xue;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 259 - 262
Publisher: IEEE
 
» Dual-Frequency Ultrasound Transducers for the Detection of Morphological Changes of Deep-Layered Muscles
Abstract:
It is evident that surface electromyography (sEMG)-based sensing approach for human–machine interfaces has some inherent limitations for applications requiring morphological changes information of deep-layered muscles, such as dexterous prosthetic hands. In this paper, the design, simulation, fabrication, and evaluation for a series of novel structured ultrasound transducers are conducted in order to develop a type of A-mode ultrasound transducers that overcome the drawbacks of the sEMG-based sensing. The transducers cover single-frequency and dual-frequency types. Their key parameters, the acoustic impedance and thickness of the matching layer, are simulated and verified by PZFlex. The parameters are designed as 0.3 times of the 1–3 composite piezoelectric’s acoustic impedance and 0.25 times of the wavelength, respectively. The characterizations of the dual-frequency transducers significantly outperform single-frequency transducers. The experiments of recognizing dexterous hand gesture are designed to detect morphological changes information of deep-layered muscles. The classification accuracy improvements with linear discrimination analysis are 7.3% and 4.7%, and with support vector machine are 14.1% and 13.4% for the horizontal stacked and annulus array. This preliminary study concludes that the dual-frequency transducers have huge potential for applications that need contraction information of deep-layered muscles over the single-frequency transducers, letting alone sEMG-based sensors.
Autors: Xueli Sun;Xingchen Yang;Xiangyang Zhu;Honghai Liu;
Appeared in: IEEE Sensors Journal
Publication date: Feb 2018, volume: 18, issue:4, pages: 1373 - 1383
Publisher: IEEE
 
» Dual-Loop Digital Control of a Three-Phase Power Supply Unit With Reduced Sensor Count
Abstract:
Widespread deployment of voltage source inverter units in high penetration applications such as distributed generation and stand-alone renewable energy conditioning imposes stringent demands on reliability and output voltage regulation. Reported literature provides numerous solutions for output voltage regulation, which includes twin aspects of command tracking and output impedance control. Most of these methods rely on the measurement of at least two separate variables per phase, which compromises overall reliability. This paper focuses on a dual-loop voltage regulation approach requiring only output voltage measurement. The outer loop of a control scheme is used to assure prompt tracking of the inverter output voltage, whereas the inner derivative feedback loop improves system stability by damping the output filter resonance. Digital realization of this derivative term is generally a challenge with many methods currently developed for resolving it. These methods are, however, still facing drawbacks, which have inclusively been explained in this paper. Subsequently, a new digital derivative is proposed whose performance is predicted analytically and then validated through experimental results with a 7.5-kVA inverter prototype.
Autors: Sanjay Tolani;Sridhar Joshi;Parthasarathi Sensarma;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 367 - 375
Publisher: IEEE
 
» Dual-Mode Generalized Spatial Modulation MIMO for Visible Light Communications
Abstract:
In this letter, we propose the optimal constellation designs of the single-mode and dual-mode generalized spatial modulation (GSM) in terms of the average optical power for indoor visible light communication systems. At receiver, an ordered-block maximum likelihood detection is performed to balance the tradeoff between the performance and the computational complexity. Our simulation results show that the dual-mode scheme outperforms SM and single-mode GSM by about 4 and 2 dB, respectively, for 5 bit/s/Hz in terms of bit error rate.
Autors: C. Rajesh Kumar;R. K. Jeyachitra;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 280 - 283
Publisher: IEEE
 
» Dual-Operation Regime Thulium-Doped Fiber Laser and Its Applications in Cascaded Raman Light and Supercontinuum Generation
Abstract:
We report on a passively mode-locked thulium-doped fiber laser (TDFL) with dual operation regimes and applications in cascaded Raman light and supercontinuum generation. The mode-locking is initiated by using a semiconductor saturable absorber mirror (SESAM) and can operate at both fundamental mode-locking and noise-like twin-pulse regimes. Output power can be scaled up through two-stage amplifications, and then was further fed into a segment of ultrahigh numerical aperture (NA) single-mode fiber with a length of ∼30 m. At the fundamental mode-locking regime, two orders of stokes lights can be generated, centered at 2.13 and 2.35 μm, respectively, with a maximum total power of 3.75 W. At the noise-like twin-pulse regime, a near-infrared supercontinuum from 1.93 to 2.46 μm was generated with a maximum average output power of 2.5 W. It is, to the best of our knowledge, the first demonstration of both cascaded Raman light and supercontinuum generation with the same system.
Autors: Zhijian Zheng;Deqin Ouyang;Junqing Zhao;Peiguang Yan;Jinzhang Wang;Shenghua Lin;Shuangchen Ruan;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 9
Publisher: IEEE
 
» Dual-Side Optimization for Cost-Delay Tradeoff in Mobile Edge Computing
Abstract:
Mobile code offloading (MCO) is a technology that offloads computing tasks from mobile devices to remote servers managed by code offload service providers (CSPs). Nowadays, it is recommended that the remote servers be placed on the edge of the network to support modern applications, e.g., augmented reality, which demand stringent and ultralow latency or high bandwidth. To date, previous studies have independently addressed code offloading policy in mobile devices and pricing/server provisioning policies in the CSP; moreover, the system models for both user side and CSP side have not adequately reflected their practical aspects. This paper designs a practical model for the both sides and takes account of them in an integrated MCO framework simultaneously. By leveraging Lyapunov drift-plus-penalty technique, we propose code offloading, local CPU clock frequency, and network interface selection policies for mobile users, and propose MCO service pricing and server provisioning policies for the CSP in each of a competition scenario and a cooperation scenario. In the competition scenario, we propose a Com-UC algorithm for mobile users and a Com-PC algorithm for the CSP with the aim to minimize each cost for each queue stability constraint. In the cooperation scenario, we propose a Coo-JC algorithm with the aim to minimize their sum cost for both mobile users and CSP. Via trace-driven simulations, we demonstrate that Com-UC saves at most 71% of its cost and Com-PC attains 82% profit gain for the same delay compared to existing algorithms; moreover, the cooperation between mobile users and CSP additionally reduces costs and delays.
Autors: Yeongjin Kim;Jeongho Kwak;Song Chong;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1765 - 1781
Publisher: IEEE
 
» Dynamic Analysis of Small Wind Turbines Frequency Support Capability in a Low-Power Wind-Diesel Microgrid
Abstract:
When wind power accounts for a large portion of the islanded microgrid power, it may need to support the ac bus frequency regulation. The increasing penetration of variable speed wind turbines (WTs) in microgrids leads to a lower inertia, as the rotational speed of the turbine and the grid is decoupled by power electronic converters. Lower system inertia results in a larger and faster frequency deviation after occurrence of abrupt variations on generation and load. It is possible to implement control loops in the WT converters to provide a virtual inertia and support frequency regulation in the microgrid. This paper investigates the variables related to the frequency compensation capability of WT, such as kinetic energy, dc-link capacitance, turbine size, wind penetration, number of turbines, operating region along the power curve, power reserve and droop control gain, etc. The analysis is structured as a design of experiment (DOE) to have a clear and organized comparison of multiple system configurations. An optimal control technique is applied to provide fair comparison among the system variables. A flowchart explaining how the DOE and controllers gains were defined is provided.
Autors: Raffael Engleitner;Ademir Nied;Mariana Santos Matos Cavalca;Jean Patric da Costa;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 102 - 111
Publisher: IEEE
 
» Dynamic Compensation Technique for POF Curvature Sensors
Abstract:
Polymer optical fibers (POF) can be applied as curvature sensors due to its high strain limits, fracture toughness, and flexibility in bend. However, POFs present viscoelastic behavior, which leads to a phase lag between the stress and strain. The polymer viscoelasticity can be associated to the high hysteresis and the errors that curvature sensors based on POF may present. For this reason, this paper proposes a dynamic compensation technique based on the angular velocity of the sensor. The technique comprises of initial quasi-static tests and tests with different angular velocities for the reduction of the sensor root mean squared error (RMSE) and hysteresis. Results show a reduction of both hysteresis and RMSE in almost all angular velocities tested. The mean reduction of the hysteresis is 20%. Whereas a mean reduction of about 3 times of the RMSE was obtained. Furthermore, the compensation technique results on a calibration equation, which can be applied in real-time measurements.
Autors: Arnaldo Gomes Leal-Junior;Anselmo Frizera;Maria José Pontes;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2018, volume: 36, issue:4, pages: 1112 - 1117
Publisher: IEEE
 
» Dynamic Fiber-Optic Shape Sensing Using Fiber Segment Interferometry
Abstract:
Dynamic fiber-optic shape sensing, often also referred to as curvature or bend sensing, is demonstrated using fiber segment interferometry, where chains of fiber segments, separated by broadband Bragg grating reflectors, are interrogated using range-resolved interferometry. In this paper, the theory of interferometric curvature sensing using fiber segments is developed in detail, including techniques to infer lateral displacements from the measured differential strain data and methods for directional calibration of the sensor. A proof-of-concept experiment is performed, where four fiber strings, each containing four fiber segments of gauge length 20 cm each, are attached to the opposing sides of a flexible support structure and the resulting differential strain measurements are used to determine the lateral displacements of a 0.8 m cantilever test object in two dimensions. Dynamic tip displacement measurements at noise levels over a 21 kHz bandwidth demonstrate the suitability of this approach for highly sensitive and cost-effective fiber-optic lateral displacement or vibration measurements.
Autors: Thomas Kissinger;Edmond Chehura;Stephen E. Staines;Stephen W. James;Ralph P. Tatam;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2018, volume: 36, issue:4, pages: 917 - 925
Publisher: IEEE
 
» Dynamic Linear Gradient Array for Traveling Wave Magnetic Particle Imaging
Abstract:
Magnetic particle imaging (MPI) is a young imaging modality using the nonlinear magnetization properties of superparamagnetic iron-oxide nanoparticles to acquire them. It is a highly sensitive and fast method allowing both a quantitative and a qualitative analysis of the measured signal. Since its first publication in 2005, several different scanner types have been presented. Most of them work with permanent magnets and therefore have a small field of view. In 2014, an alternative scanner concept, the traveling wave MPI (TWMPI), was presented, which allows scanning an entire mouse-sized volume at once. In this paper, a detailed description of the main field generator, the dynamic linear gradient array (dLGA), used for TWMPI is given. This paper guides the reader to the first dLGA prototype, deriving relations between the length of the dLGA and the diameter of the segment coils.
Autors: P. Vogel;P. Klauer;M. A. Rückert;T. A. Bley;W. H. Kullmann;P. M. Jakob;V. C. Behr;
Appeared in: IEEE Transactions on Magnetics
Publication date: Feb 2018, volume: 54, issue:2, pages: 1 - 9
Publisher: IEEE
 
» Dynamic Modeling and Feasibility Analysis of a Solid-State Transformer-Based Power Distribution System
Abstract:
This paper presents a comprehensive state-space dynamic model of a future power distribution system for plug-and-play interface of distributed renewable energy resources and distributed energy storage devices. The system, called the future renewable electric energy delivery and management (FREEDM) system, comprises of multiple solid-state transformers (SSTs), and load, generation, and storage connected to each SST in a distributed network. The system allows for high penetration of renewable generation with energy storage at the distribution level. A physics-based 70th-order state-space average model is first developed considering the physical and controller properties of a single-SST FREEDM system along with its distribution components. This fundamental model is then extended to build a multi-SST FREEDM system for feasibility and dynamics behavior analysis of the entire system, which is essential to ensure system power balance. The full average model with multiple SSTs has been incorporated in an IEEE 34 bus distribution testbed for a scaled analysis of the system.
Autors: Md Tanvir Arafat Khan;Alireza Afiat Milani;Aranya Chakrabortty;Iqbal Husain;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 551 - 562
Publisher: IEEE
 
» Dynamic Power Management and Control of a PV PEM Fuel-Cell-Based Standalone ac/dc Microgrid Using Hybrid Energy Storage
Abstract:
In this paper, a dynamic power management scheme (PMS) is proposed for a standalone hybrid ac/dc microgrid, which constitutes a photovoltaic (PV)-based renewable energy source, a proton exchange membrane fuel cell (FC) as a secondary power source, and a battery and a supercapacitor as hybrid energy storage. The power management algorithm accounts for seamless operation of the microgrid under various modes and state-of-charge limit conditions of hybrid energy storage when all the sources, storages, and loads are connected directly at the dc link. The PMS generates current references for dc converter current controllers of the FC, the battery, and the supercapacitor. The average and fluctuating power components are separated using a moving average filter. The dc-link voltage regulation under dynamic changes in load and source power variation is proposed. Also, PV power curtailment through control is formulated. The proposed power management is modified and extended to multiple PV generation systems and batteries, with all the sources and storages geographically distributed and operating under multitime-scale adaptive-droop-based control with supervisory control for mode transition. The proposed PMS is validated using simulation results. Also, field programmable gate array/Labview-based laboratory-scale experimental results are presented to validate the PMS under various critical conditions.
Autors: Rishi Kant Sharma;Sukumar Mishra;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 526 - 538
Publisher: IEEE
 
» Dynamic SCMA Codebook Assignment Methods: A Comparative Study
Abstract:
In this letter, we consider a sparse code multiple access (SCMA) system, in which we assign the subcarriers to users based on the available channel gains between the users and base station over all subcarriers, referred to as channel state information. The effect of this process, referred to here as codebook assignment, has not been considered before on link-level performance of an SCMA. We propose three codebook assignment methods and compare their performance with each other as well as with the conventional case, where no assignment is performed. It is shown that significant performance improvement is achieved when any of the proposed methods is deployed. Through one of the proposed methods, we show that a trade-off between user performance fairness and performance is achievable.
Autors: Milad Dabiri;Hamid Saeedi;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 364 - 367
Publisher: IEEE
 
» Dynamic Small Cell Clustering and Non-Cooperative Game-Based Precoding Design for Two-Tier Heterogeneous Networks With Massive MIMO
Abstract:
In this paper, we investigate the dynamic small cell (SC) clustering strategy and their precoding design problem for interference coordination in two-tier heterogeneous networks (HetNets) with massive MIMO (mMIMO). To reduce interference among different SCs, an interference graph-based dynamic SC clustering scheme is proposed. Based on this, we formulate an optimization problem as design precoding weights at macro base station (MBS) and clustered SCs for maximizing the downlink sum rate of SC users (SUs) subject to the power constraint of each SC BS (SBS), while mitigating inter-cluster, eliminating inter-tier, intra-cluster and multi-macro user (MU) interference. To eliminate the inter-tier and multi-MU interference simultaneously, we propose a clustered SC block diagonalization precoding scheme for the MBS. Next, each SU’s precoding vector at clustered SCs is designed as the product of the following two parts. The first part is designed with singular value decomposition to remove the intra-cluster interference. The second part is designed to coordinate the inter-cluster interference for maximizing the downlink sum rate of SUs, which is a non-convex optimization problem and difficult to solve directly. A non-cooperative game-based distributed algorithm is proposed to obtain a suboptimal solution. Meanwhile, we prove the existence and uniqueness of Nash equilibrium for the formed game. Finally, simulation results verify the effectiveness of our proposed schemes.
Autors: Wanming Hao;Osamu Muta;Haris Gacanin;Hiroshi Furukawa;
Appeared in: IEEE Transactions on Communications
Publication date: Feb 2018, volume: 66, issue:2, pages: 675 - 687
Publisher: IEEE
 
» Dynamic Spectrum Reservation for CR Networks in the Presence of Channel Failures: Channel Allocation and Reliability Analysis
Abstract:
Providing channel access opportunities for new service requests and guaranteeing continuous connections for ongoing flows until service completion are two challenges for service provisioning in wireless networks. Channel failures, which are typically caused by hardware and software failures or/and by intrinsic instability in radio transmissions, can easily result in network performance degradation. In cognitive radio networks (CRNs), secondary transmissions are inherently vulnerable to connection breaks due to licensed users’ arrivals as well as channel failures. To explore the advantages of channel reservation on performance improvement in error-prone channels, we propose and analyze a dynamic channel reservation (DCR) algorithm and a dynamic spectrum access (DSA) scheme with three access privilege variations. The key idea of the DCR algorithm is to reserve a dynamically adjustable number of channels for the interrupted services to maintain service retainability for ongoing users or to enhance channel availability for new users. Furthermore, the DCR algorithm is embedded in the DSA scheme enabling spectrum access of primary and secondary users with different access privileges based on access flexibility for licensed shared access. The performance of such a CRN in the presence of homogeneous and heterogeneous channel failures is investigated considering different channel failure and repair rates.
Autors: Indika A. M. Balapuwaduge;Frank Y. Li;Vicent Pla;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 882 - 898
Publisher: IEEE
 
» Dynamic, Fine-Grained Data Plane Monitoring With Monocle
Abstract:
Ensuring network reliability is important for satisfying service-level objectives. However, diagnosing network anomalies in a timely fashion is difficult due to the complex nature of network configurations. We present Monocle — a system that uncovers forwarding problems due to hardware or software failures in switches, by verifying that the data plane corresponds to the view that an SDN controller installs via the control plane. Monocle works by systematically probing the switch data plane; the probes are constructed by formulating the switch forwarding table logic as a Boolean satisfiability (SAT) problem. Our SAT formulation quickly generates probe packets targeting a particular rule considering both existing and new rules. Monocle can monitor not only static flow tables (as is currently typically the case), but also dynamic networks with frequent flow table changes. Our evaluation shows that Monocle is capable of fine-grained monitoring for the majority of rules, and it can identify a rule suddenly missing from the data plane or misbehaving in a matter of seconds. In fact, during our evaluation Monocle uncovered problems with two hardware switches that we were using in our evaluation. Finally, during network updates Monocle helps controllers cope with switches that exhibit transient inconsistencies between their control and data plane states.
Autors: Peter Perešíni;Maciej Kuźniar;Dejan Kostić;
Appeared in: IEEE/ACM Transactions on Networking
Publication date: Feb 2018, volume: 26, issue:1, pages: 534 - 547
Publisher: IEEE
 
» Dynamically Adaptable Pipeline for Energy-Efficient Microarchitectures Under Wide Voltage Scaling
Abstract:
This paper introduces dynamically adaptable pipelines to enable microarchitecture-driven voltage scaling, adapting the microarchitecture to the most energy-efficient configuration for a time-varying throughput target or supply voltage requirement . Dynamic adaptation of the pipeline depth is introduced to curtail the contribution that dominates the overall energy (e.g., dynamic, clock, and leakage), as dictated by the throughput target and . Microarchitectural adaptation of the pipeline depth also flattens the energy dependence on around the minimum-energy point, thus facilitating nearly minimum-energy operation in the presence of inaccuracies in (e.g., discretization and non-idealities). Dynamically adaptable pipelines can be fully integrated with automated digital flows at design time and with dynamic voltage scaling schemes at run time. The proposed approach is demonstrated with a 256-point radix-4 fixed-point FFT engine on a 40-nm test chip. Measurements show energy savings up to 30% (38%) at iso-throughput (iso-voltage) in an area and the maximum performance penalty of 5% and 11%, respectively.
Autors: Saurabh Jain;Longyang Lin;Massimo Alioto;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2018, volume: 53, issue:2, pages: 632 - 641
Publisher: IEEE
 
» Dynamically Consistent Online Adaptation of Fast Motions for Robotic Manipulators
Abstract:
The planning and execution of real-world robotic tasks largely depends on the ability to generate feasible motions online in response to changing environment conditions or goals. A spline deformation method is able to modify a given trajectory so that it matches the new boundary conditions, e.g., on positions, velocities, accelerations, etc. At the same time, the deformed motion preserves velocity, acceleration, jerk, or higher derivatives of motion profile of the precalculated trajectory. The deformed motion possessing such properties can be expressed by translation of original trajectory and spline interpolation. This spline decomposition considerably reduces the computational complexity and allows real-time execution. Formal feasibility guarantees are provided for the deformed trajectory and for the resulting torques. These guarantees are based on the special properties of Bernstein polynomials used for the deformation and on the structure of the chosen computed-torque control scheme. The approach is experimentally evaluated in a number of planar volleyball experiments using 3 degree-of-freedom robots and human participants.
Autors: Alexander Pekarovskiy;Thomas Nierhoff;Sandra Hirche;Martin Buss;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 166 - 182
Publisher: IEEE
 
» Dynamically Regulating Mobile Application Permissions
Abstract:
Current smartphone operating systems employ permission systems to regulate how apps access sensitive resources. These systems are not well-aligned with users’ privacy expectations: users often have no idea how often and under what circumstances their personal data is accessed. We conducted a 131-person field study to devise ways to systematically reduce this disconnect between expectations and reality. We found that a significant portion of participants make contextual privacy decisions: when determining whether access to sensitive data is appropriate, they consider what they are doing on their phones at the time, including whether they are actively using the applications requesting their data. We show that current privacy mechanisms do not do a good job of accounting for these contextual factors, but that by applying machine learning to account for context, we can reduce privacy violations by 80, while also minimizing user involvement.
Autors: Primal Wijesekera;Arjun Baokar;Lynn Tsai;Joel Reardon;Serge Egelman;David Wagner;Konstantin Beznosov;
Appeared in: IEEE Security & Privacy
Publication date: Feb 2018, volume: 16, issue:1, pages: 64 - 71
Publisher: IEEE
 
» Dynamics Model and Vibration Control of Piezoelectric Feeder in Semiconductor Manufacturing Assembly
Abstract:
A piezoelectric vibration feeder is a necessary device for semiconductor manufacturing assembly. Its function is to automatically transport individual chip parts by precision vibration instead of by manual operation. In this paper, a mechanical structure for the piezoelectric feeder and electrical controller is designed and a prototype is developed. A vibration simulation model is established in ANSYS by the finite element method (FEM), and the frequency and vibration modal is attained. The mass-elastic model is established and the frequency is calculated by the numerical method. To drive and control the vibration feeder, a hardware driver consisting of an ARM microcontroller, a sinusoidal pulse width modulation driver module, an inverter circuit of insulated gate bipolar transistor modules, and an LC filter is designed. To achieve resonant vibration, a self-tuned proportional integral derivative (PID) controller for frequency tracking is investigated using MATLAB Simulink simulation. The dynamics and performance of vibration control are then verified through experimental testing using a laser Doppler vibrometer and an impedance analyzer. The mechanical frequencies of the piezoelectric feeder in the FEM, the numerical model, and the experimental measurement are found to agree well. The PID controller used for frequency tracking ensures the resonant vibration, which improves the efficiency and robustness of the piezoelectric feeder.
Autors: Zhili Long;Hao Shen;Jianguo Zhang;Shuang Zhao;Yongcheng Lin;Zuohua Li;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Feb 2018, volume: 31, issue:1, pages: 97 - 107
Publisher: IEEE
 
» Dynamics-Based Motion Deblurring Improves the Performance of Optical Character Recognition During Fast Scanning of a Robotic Eye
Abstract:
This paper presents a quantitative evaluation of the dynamics-based deblurring method using an optical character recognition (OCR) technology. Although various image deblurring algorithms have been studied, there has been no standard performance metric; deblurred images have often been evaluated in a qualitative manner. In this study, blurry images containing alphanumeric characters were obtained in the course of rapid motion using a robotic vision system. The obtained blurry images were recovered by the dynamics-based deblurring method. For a quantitative evaluation, OCR rates from the deblurred images by the dynamics-based method were calculated and compared with those by other well-known methods. Experiment results show that the dynamics-based method has the best quantitative results.
Autors: Michael D. Kim;Jun Ueda;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Feb 2018, volume: 23, issue:1, pages: 491 - 495
Publisher: IEEE
 
» Easy Path Programming: Elevate Abstraction Level for Network Functions
Abstract:
As datacenter networks become increasingly programmable with proliferating network functions, network programming languages have emerged to simplify the program development of the network functions. While network functions exhibit high level abstraction over operations on the traffic flow and the interconnections among the operations, the existing languages usually require programming with detailed knowledge about the packet processing patterns at the switches. Such a mismatch between the program abstraction and development details makes developing network functions a nontrivial task. To solve the problem, this paper introduces the easy path programming (EP2) framework. EP2 offers a high-level abstraction to simplify the program design process of the network functions. EP2 also provides a language that captures the common properties of network functions and uses predicates and primitives as basic language components. Specifically, predicates describe when to handle a flow with a global view of the flow dynamics; and primitives describe how to choose a path for a specific flow. Furthermore, EP2 has its own runtime system to support the language and the abstraction model, especially to hide the low level packet-processing behavior at the data plane from the programmers. Throughout this paper, cases are given to illustrate the EP2 abstraction model, language details and benefits. The expressiveness of EP2, the potential overhead of the runtime system and the efficiency of the network functions generated by EP2 are evaluated. The results show that EP2 can achieve comparable performance while reducing programming efforts.
Autors: Fei Chen;Chunming Wu;Xiaoyan Hong;Bin Wang;
Appeared in: IEEE/ACM Transactions on Networking
Publication date: Feb 2018, volume: 26, issue:1, pages: 189 - 202
Publisher: IEEE
 
» Easy PRAM-Based High-Performance Parallel Programming with ICE
Abstract:
Parallel machines have become more widely used. Unfortunately parallel programming technologies have advanced at a much slower pace except for regular programs. For irregular programs, this advancement is inhibited by high synchronization costs, non-loop parallelism, non-array data structures, recursively expressed parallelism and parallelism that is too fine-grained to be exploitable. We present ICE, a new parallel programming language that is easy-to-program, since: (i) ICE is a synchronous, lock-step language so there is no need for programmer-specified synchronization; (ii) for a PRAM algorithm its ICE program amounts to directly transcribing it; and (iii) the PRAM algorithmic theory offers unique wealth of parallel algorithms and techniques. We propose ICE to be a part of an ecosystem consisting of the XMT architecture, the PRAM algorithmic model, and ICE itself, that together deliver on the twin goal of easy programming and efficient parallelization of irregular programs. The XMT architecture, developed at UMD, can exploit fine-grained parallelism in irregular programs. We have built the ICE compiler which translates the ICE language into the multithreaded XMTC language; the significance of this is that multi-threading is a feature shared by practically all current scalable parallel programming languages thus providing a method to compile ICE code. As one indication of ease of programming, we observed a reduction in code size in 11 out of 16 benchmarks as compared to hand-optimized XMTC. For these programs, the average reduction in number of lines of code was 35.5 percent. The remaining 5 benchmarks had almost the same code size for both ICE and hand-optimized XMTC. Our main result is perhaps surprising: The run-time was comparable to XMTC with a 0.53 percent average gain for ICE across all benchmarks.
Autors: Fady Ghanim;Uzi Vishkin;Rajeev Barua;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Feb 2018, volume: 29, issue:2, pages: 377 - 390
Publisher: IEEE
 
» Eco-Driving Assistance System for a Manual Transmission Bus Based on Machine Learning
Abstract:
Driving assistance systems (DAS) is a key technology to improve fuel economy for in-use vehicles. This also reduces the operational cost of running a fleet of these vehicles, such as city buses. In this paper, we develop a novel white-box evaluation model using machine learning for a manual transmission bus based on previous research about fuel consumption sensitivity to driving style. Using the proposed evaluation model, an algorithm for learning path planning (LPP) for a driving style is also proposed. The LPP method plans a step-by-step shortest learning path for different driving styles to achieve eco-driving, while increasing the driver’s acceptance and adaptation of DAS. Simulation results based on vehicle and engine physical models show that the proposed evaluation model, a pure data model, can be used as an alternative to physical model for the eco-driving prompt strategy. The results of the verification show that the proposed strategy can progressively guide the driver to improve the fuel consumption by 6.25% with minimal changes to driver’s driving task and driving style.
Autors: Hongjie Ma;Hui Xie;David Brown;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Feb 2018, volume: 19, issue:2, pages: 572 - 581
Publisher: IEEE
 
» Edge Computing for the Internet of Things
Abstract:
Autors: Ju Ren;Yi Pan;Andrzej Goscinski;Raheem A. Beyah;
Appeared in: IEEE Network
Publication date: Feb 2018, volume: 32, issue:1, pages: 6 - 7
Publisher: IEEE
 
» Edge Computing Gateway of the Industrial Internet of Things Using Multiple Collaborative Microcontrollers
Abstract:
An Internet of Things gateway serves as a key intermediary between numerous smart things and their corresponding cloud networking servers. A typical conventional gateway system uses a high-level embedded microcontroller (MCU) as its core; that MCU performs low-level perception-layer device network management, upper-level cloud server functions, and remote mobile computation services. However, in edge computing, many factors need to be considered when designing an IoT gateway, such as minimizing the response time, the power consumption, and the bandwidth cost. Regarding system scalability, computational efficiency, and communication efficiency, solutions that use a single MCU cannot deliver IoT functionality such as big data collection, management, real-time communication, expandable peripherals, and various other services. Therefore, this article proposes an innovative multi-MCU system framework combining a field-programmable- gate-array-based hardware bridge and multiple scalable MCUs to realize an edge gateway of a smart sensor fieldbus network. Through distributed and collaborative computing, the multi-MCU edge gateway can efficiently perform fieldbus network management, embedded data collection, and networking communication, thereby considerably reducing the real-time power consumption and improving scalability compared to the existing industrial IoT solutions.
Autors: Ching-Han Chen;Ming-Yi Lin;Chung-Chi Liu;
Appeared in: IEEE Network
Publication date: Feb 2018, volume: 32, issue:1, pages: 24 - 32
Publisher: IEEE
 
» Edge Computing in the Industrial Internet of Things Environment: Software-Defined-Networks-Based Edge-Cloud Interplay
Abstract:
The emergence of the Industrial Internet of Things (IIoT) has paved the way to real-time big data storage, access, and processing in the cloud environment. In IIoT, the big data generated by various devices such as-smartphones, wireless body sensors, and smart meters will be on the order of zettabytes in the near future. Hence, relaying this huge amount of data to the remote cloud platform for further processing can lead to severe network congestion. This in turn will result in latency issues which affect the overall QoS for various applications in IIoT. To cope with these challenges, a recent paradigm shift in computing, popularly known as edge computing, has emerged. Edge computing can be viewed as a complement to cloud computing rather than as a competition. The cooperation and interplay among cloud and edge devices can help to reduce energy consumption in addition to maintaining the QoS for various applications in the IIoT environment. However, a large number of migrations among edge devices and cloud servers leads to congestion in the underlying networks. Hence, to handle this problem, SDN, a recent programmable and scalable network paradigm, has emerged as a viable solution. Keeping focus on all the aforementioned issues, in this article, an SDN-based edge-cloud interplay is presented to handle streaming big data in IIoT environment, wherein SDN provides an efficient middleware support. In the proposed solution, a multi-objective evolutionary algorithm using Tchebycheff decomposition for flow scheduling and routing in SDN is presented. The proposed scheme is evaluated with respect to two optimization objectives, that is, the trade-off between energy efficiency and latency, and the trade-off between energy efficiency and bandwidth. The results obtained prove the effectiveness of the proposed flow scheduling scheme in the IIoT environment.
Autors: Kuljeet Kaur;Sahil Garg;Gagangeet Singh Aujla;Neeraj Kumar;Joel J. P. C. Rodrigues;Mohsen Guizani;
Appeared in: IEEE Communications Magazine
Publication date: Feb 2018, volume: 56, issue:2, pages: 44 - 51
Publisher: IEEE
 
» Editor's Note
Abstract:
Autors: Nei Kato;Mohsen Guizani;
Appeared in: IEEE Network
Publication date: Feb 2018, volume: 32, issue:1, pages: 3 - 3
Publisher: IEEE
 
» Editor-in-Chief Message: Embracing the Era of Intelligent Visual Technology and Systems
Abstract:
It is such a great honor and pleasure for me to assume the role of Editor-in-Chief of IEEE Transactions on Circuits and Systems for Video Technology (TCSVT), starting in January 2018. I have been involved in TCSVT for a long time, initially as a reader as early as in 1993 when I was still a graduate student, then as a long-time contributor in the role of an author and a reviewer, as an Associate Editor from 2002 to 2008, and later as a Deputy Editor-in-Chief from 2014 to 2017. I look forward to this exciting yet challenging opportunity to lead TCSVT to the next level.
Autors: Shipeng Li;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Feb 2018, volume: 28, issue:2, pages: 273 - 274
Publisher: IEEE
 
» Editorial
Abstract:
Dear fellow dielectricians, It will be an honor and a pleasure to serve as your DEIS president during 2018. My special thanks go to the DEIS Administrative Committee for entrusting me with this office; to the former presidents Simon Rowland, Frank Hegeler, and Paul Lewin and to the outgoing Standing-Committee chairs for their support and advice; and to the new administrative and technical vice presidents, Paul Gaberson and Brian Stewart, as well as the new secretary, Axel Mellinger, and the newly appointed or reappointed Standing-Committee chairs for kindly agreeing to dedicate valuable time as DEIS volunteers. I very much look forward to working with all of you. Together, we will make a difference.
Autors: Reimund Gerhard;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: Feb 2018, volume: 34, issue:1, pages: 4 - 4
Publisher: IEEE
 
» Editorial Celebrating 25 Years of the IEEE Transactions on Fuzzy Systems
Abstract:
Autors: J. BEZDEK;J. KELLER;N. PAL;C.-T. LIN;J. GARIBALDI;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Feb 2018, volume: 26, issue:1, pages: 1 - 5
Publisher: IEEE
 
» Editorial February 2018 Issue
Abstract:
This issue of the IEEE Transactions on Engineering Management includes 13 research articles. The relevance and usefulness of the articles are summarized.
Autors: Rajiv Sabherwal;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Feb 2018, volume: 65, issue:1, pages: 1 - 5
Publisher: IEEE
 
» Effect of a Trap Zone in Reducing Nanoparticle Contamination of Wafers and Photomasks in Parallel Airflowp
Abstract:
Particle contamination control is important for increasing the yield in semiconductor manufacturing. In this paper, a trap zone was suggested to reduce the level of particulate contamination of wafers and photomasks during transport in horizontal direction. Trap zone efficiency was numerically and theoretically analyzed by calculating local deposition velocity onto a critical surface representing a wafer or a photomask. The effects of diffusion, gravitational settling, convection, and thermophoresis on particle behavior were considered. The deposition velocity onto the critical surface was found to be effectively reduced with the use of the trap zone, especially for nanoparticles of large diffusivity. As the trap zone became longer, the degree of critical surface contamination by nanoparticles was estimated to be more reduced. An equation was suggested to estimate the reduction of particulate contamination of the critical surface as a function of the trap zone length. It is anticipated that the results of this paper are very helpful for designing wafer/photomask transport systems with a reduced level of contamination by nanoparticles.
Autors: Sang-Hee Woo;Jungsuk Lee;Se-Jin Yook;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Feb 2018, volume: 31, issue:1, pages: 87 - 96
Publisher: IEEE
 
» Effect of Control-Loops Interactions on Power Stability Limits of VSC Integrated to AC System
Abstract:
This paper investigates the effect of control-loops interactions on power stability limits of the voltage-source converter (VSC) as connected to an ac system. The focus is put on the physical mechanism of the control-loops interactions in the VSC, revealing that interactions among the control loops result in the production of an additional loop. The open-loop gain of the additional loop is employed to quantify the severity of the control-loop interactions. Furthermore, the power current sensitivity, closely related to control-loops interactions, is applied to estimate the maximum transferrable power of the VSC connected to an ac grid. On that basis, stability analysis results show that interactions between dc-link voltage control and phase-locked loop restrict the power angle to about 51° for stable operation with no dynamic reactive power supported. Conversely, the system is capable of approaching the ac-side maximum power transfer limits with alternating voltage control included. Simulations in MATLAB/Simulink are conducted to validate the stability analysis.
Autors: Yunhui Huang;Dong Wang;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 301 - 310
Publisher: IEEE
 
» Effect of La Addition on the Electrical Characteristics and Stability of Solution-Processed LaInO Thin-Film Transistors With High- ${k}$ ZrO2 Gate Insulator
Abstract:
In this paper, solution-processed ZrO2 thin films are used to be as insulting layers for lanthanum indium oxide (LaInO) thin-film transistors (TFTs) with different La doping contents. The influence of La addition on the electrical properties and stability under bias stress and temperatures stress for LaInO TFTs is investigated in detail. With the improvement of La doping contents, the saturation mobility () decreases from 48.8 to 32.7 cm2 and the threshold voltage (VT) increases from 1.12 to 1.76 V. When La doping concentration is 10 mol%, LaInO TFT has a small subthreshold swing of 0.12 V/dec. Meanwhile, the stability is improved obviously. It is attributed to the strong bonding strength of La–O relative to that of In–O, resulting in the reduction of trap states. X-ray photoelectron spectroscopy shows that the generation of oxygen vacancies can effectively be suppressed by La addition. The calculation of density of states and the measurement of the capacitance–voltage can also further confirm that the density of trap states is decreased by La addition, and thus the stability of LaInO TFTs can get an obvious improvement.
Autors: Cheng-Yu Zhao;Jun Li;De-Yao Zhong;Chuan-Xin Huang;Jian-Hua Zhang;Xi-Feng Li;Xue-Yin Jiang;Zhi-Lin Zhang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 526 - 532
Publisher: IEEE
 
» Effect of Motor Voltage Unbalance on Motor Vibration: Test and Evaluation
Abstract:
There have been many discussions on the importance of balanced power supply for both best performance and for lower vibration during operation of industrial motors in petrochemical duty and related installations. Results of tests that were conducted on several low-voltage IEEE 841 motors to observe the effect on vibration due to unbalanced power supply will be presented. Various increments of voltage imbalance from 1% up to 10% were tested and monitored on several pole speeds. This paper will present actual test data collected, along with a discussion on how these results relate and impact the various vibration testing and operational conditions provided within industry standards.
Autors: Matthew Campbell;Gabriel Arce;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 905 - 911
Publisher: IEEE
 
» Effective and Efficient Detection of Moving Targets From a UAV’s Camera
Abstract:
Accurate and fast detection of the moving targets from a moving camera are an important yet challenging problem, especially when the computational resources are limited. In this paper, we propose an effective, efficient, and robust method to accurately detect and segment multiple independently moving foreground targets from a video sequence taken by a monocular moving camera [e.g., onboard an unmanned aerial vehicle (UAV)]. Our proposed method advances the existing methods in a number of ways, where: 1) camera motion is estimated through tracking background keypoints using pyramidal Lucas–Kanade at every detection interval, for efficiency; 2) foreground segmentation is applied by integrating a local motion history function with spatio-temporal differencing over a sliding window for detecting multiple moving targets, while the perspective homography is used at image registration for effectiveness; and 3) the detection interval is adjusted dynamically based on a rule-of-thumb technique and considering camera setup parameters for robustness. The proposed method has been tested on a variety of scenarios using a UAV camera, as well as publically available data sets. Based on the reported results and through comparison with the existing methods, the accuracy of the proposed method in detecting multiple moving targets as well as its capability for real-time implementation has been successfully demonstrated. Our method is also robustly applicable to ground-level cameras for the ITS applications, as confirmed by the experimental results. More specifically, the proposed method shows promising performance compared with the literature in terms of quantitative metrics, while the run-time measures are significantly improved for real-time implementation.
Autors: Sara Minaeian;Jian Liu;Young-Jun Son;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Feb 2018, volume: 19, issue:2, pages: 497 - 506
Publisher: IEEE
 
» Effective Doping Concentration Theory: A New Physical Insight for the Double-RESURF Lateral Power Devices on SOI Substrate
Abstract:
Double-reduced surface field (D-RESURF) technique aims to increase the doping concentration of drift regions and maintain a high breakdown voltage. However, conventional 2-D models are too complicated and unable to elaborate its physical meaning. Hence, the D-RESURF effective doping concentration (EDC) theory is proposed in this paper to explore the physical insight of the D-RESURF effect by equating the sophisticated 2-D structure to a simple 1-D RESURF model with segmented-doped p-n junction. The EDC indicates that an NPNP structure may exist because of the influence of the P-top region. Thus, two electric field valleys and one electric field peak can be formed on the surface. Based on the theory, a 1-D analytical model is presented to qualitatively and quantitatively explore the impact of D-RESURF effect on breakdown mechanism of silicon on insulator lateral double diffusion MOS. The results obtained by the proposed model are found to be sufficiently accurate comparing with TCAD simulation results.
Autors: Jun Zhang;Yu-Feng Guo;David Z. Pan;Ke-Meng Yang;Xiao-Juan Lian;Jia-Fei Yao;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 648 - 654
Publisher: IEEE
 
» Effective Learner-Centered Approach for Teaching an Introductory Digital Systems Course
Abstract:
In the Internet era, students have increasingly lost interest in traditional lectures; as a consequence, their learning motivation and exam performance have decreased. The widespread adoption of learner-centered teaching methods that address this issue faces certain barriers, including: 1) the significant faculty effort necessary to prepare e-learning materials; 2) significant extra time required for active online communication with students; 3) student resistance to taking an active role in their education; and 4) lecturers’ common belief that learner-centered teaching activities do not allow discussion of all the required topics. This paper presents a case study based on one offering of an introductory digital systems course taught with a combination of learner-centered strategies selected to overcome these barriers and improve student performance. These measures included: 1) improving the student-teacher relationship; 2) applying intriguing, inductive, and counterintuitive approaches to introducing new concepts; 3) adopting puzzle-based quizzes integrated with peer instruction; 4) using an audience response system; 5) replacing certain lectures with tutorials; 6) reducing course duration; and 7) using a graphics tablet. The results obtained demonstrate significant improvements in lecture attendance and in student performance. The author believes that the approach presented here can benefit other engineering educators in similar courses.
Autors: Piotr Dȩbiec;
Appeared in: IEEE Transactions on Education
Publication date: Feb 2018, volume: 61, issue:1, pages: 38 - 45
Publisher: IEEE
 
» Effective Removal of Gordon–Haus Jitter in Mode-Locked Fiber Lasers
Abstract:
We demonstrate the effective removal of Gordon–Haus (GH) jitter in mode-locked fiber lasers based on the narrow bandpass filtering, verified from large positive dispersion to large negative dispersion. Simulations and experiments indicate that there exists an optimum filtering bandwidth for the near-zero GH jitter along with the constant directly coupled jitter. The corresponding measured root-mean-square timing jitter (10 kHz to 10 MHz) is restrained within 0.6 dB, even though the net dispersion is largely varied by 70% of the intracavity fiber dispersion. The demonstrated effective GH jitter elimination free of the dispersion management gives an easy way for the low-jitter laser design and the related high-precision applications outside the laboratory.
Autors: Peng Qin;Sijia Wang;Minglie Hu;Youjian Song;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 8
Publisher: IEEE
 
» Effectiveness of Test-Driven Development and Continuous Integration: A Case Study
Abstract:
In a case study where a Dutch small-to-medium enterprise (SME) implemented test-driven development and continuous integration, researchers observed that the SME discovered a higher number of defects compared to a baseline case study, and that there was an increase in the focus on quality and test applications.
Autors: Chintan Amrit;Yoni Meijberg;
Appeared in: IT Professional
Publication date: Feb 2018, volume: 20, issue:1, pages: 27 - 35
Publisher: IEEE
 
» Effects of Magnetostriction on Electromagnetic Motor Vibration at Sideband Frequencies
Abstract:
This paper discusses the effects of magnetostrictions (MSs) on the vibrations of stator core of electric motor driven by pulse width modulation controllers. Special attention is given to the vibration shapes at the sideband frequencies of the switching frequency. First, based on the measured vibration shapes of an electric motor, it is shown that the vibration shapes at the sideband frequencies are strongly affected by the electromagnetic force (EM) distribution. Next, we estimate the vibration shapes of the stator by conducting coupled magnetostatic and structural finite-element analyses. It is shown that the computed and the measured vibration shapes at each sideband frequency are in good agreement. It is then demonstrated that the contributions of the EM and the MS on the stator vibration shape at each side band frequency can clearly be explained by the phase pattern of magnetic flux density on the stator teeth and back yoke of the stator core.
Autors: Masakatsu Kuroishi;Akira Saito;
Appeared in: IEEE Transactions on Magnetics
Publication date: Feb 2018, volume: 54, issue:2, pages: 1 - 8
Publisher: IEEE
 
» Efficiency of Power Ramping During Random Access in LTE
Abstract:
In this paper, we examine the impact of power ramping, number of retransmission attempts, and limitations of the physical downlink control channel (PDCCH) on the performance of random access in Long Term Evolution/Long Term Evolution-Advanced networks. We demonstrate that positive feedback exists between the maximum number of retransmissions, age-based power ramping, and PDCCH deficiency. As the result, system capacity is decreased and performance deteriorates abruptly under moderate to high traffic intensity. We show that, under power ramping and default PDCCH capacity, increasing the number of retransmissions beyond 1 or at most 2 does not bring any benefits and, in fact, is detrimental to system capacity. Increasing PDCCH capacity would enable the benefits of power ramping and allow more retransmission attempts. However, increasing the number of retransmissions combined with power ramping, while helpful under moderate to high load, will decrease system capacity.
Autors: Jelena Mišić;Vojislav B. Mišić;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1698 - 1712
Publisher: IEEE
 
» Efficient Algorithms for Sequence Analysis with Entropic Profiles
Abstract:
Entropy, being closely related to repetitiveness and compressibility, is a widely used information-related measure to assess the degree of predictability of a sequence. Entropic profiles are based on information theory principles, and can be used to study the under-/over-representation of subwords, by also providing information about the scale of conserved DNA regions. Here, we focus on the algorithmic aspects related to entropic profiles. In particular, we propose linear time algorithms for their computation that rely on suffix-based data structures, more specifically on the truncated suffix tree (TST) and on the enhanced suffix array (ESA). We performed an extensive experimental campaign showing that our algorithms, beside being faster, make it possible the analysis of longer sequences, even for high degrees of resolution, than state of the art algorithms.
Autors: Cinzia Pizzi;Mattia Ornamenti;Simone Spangaro;Simona E. Rombo;Laxmi Parida;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Feb 2018, volume: 15, issue:1, pages: 117 - 128
Publisher: IEEE
 
» Efficient and Privacy-Preserving Outsourced Calculation of Rational Numbers
Abstract:
In this paper, we propose a framework for efficient and privacy-preserving outsourced calculation of rational numbers, which we refer to as POCR. Using POCR, a user can securely outsource the storing and processing of rational numbers to a cloud server without compromising the security of the (original) data and the computed results. We present the system architecture of POCR and the associated toolkits required in the privacy preserving calculation of integers and rational numbers to ensure that commonly used outsourced operations can be handled on-the-fly. We then prove that the proposed POCR achieves the goal of secure integer and rational number calculation without resulting in privacy leakage to unauthorized parties, and demonstrate the utility and the efficiency of POCR using simulations.
Autors: Ximeng Liu;Kim-Kwang Raymond Choo;Robert H. Deng;Rongxing Lu;Jian Weng;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Feb 2018, volume: 15, issue:1, pages: 27 - 39
Publisher: IEEE
 
» Efficient Coding Architectures for Reed–Solomon and Low-Density Parity-Check Decoders for Magnetic and Other Data Storage Systems
Abstract:
High-performance error correction codes are used in high-density data storage devices to overcome noise and channel impairments. In this paper, we develop novel and efficient decoding architectures for Reed–Solomon (RS) and low-density parity-check (LDPC) codes that are used in almost all data storage devices. First, we present a high-speed low-latency hard-decision-based pipelined RS decoder architecture that computes the error locator polynomial in exactly clock cycles without parallelism. The RS decoder is a two-stage pipelined engine operating at the least latency possible, thereby, significantly reducing the size of the delay buffer. The RS decoder is implemented using Cadence tools and Kintex-7 field programmable gate array (FPGA). The technology-scaled normalized throughput of the pipelined RS decoder is almost two times compared with the existing decoders. The overall processing latency is reduced by almost 80% compared with the existing designs. Second, we design a high-throughput LDPC decoder using layered and non-layered min-sum algorithm based on non-uniform quantization (NUQ) on an FPGA kit. Unlike the standard state-of-the-art uniform quantization used in virtually all decoder circuits, our NUQ technique: 1) achieves a slight performance improvement of ~0.1 dB in the signal-to-noise ratio using equal number of bits and 2) yields 20% area savings (using 1 bit less) for the block RAMs used for storing intermediate check node and variable node messages.
Autors: Arijit Mondal;Satyannarayana Thatimattala;Vamshi Krishna Yalamaddi;Shayan Srinivasa Garani;
Appeared in: IEEE Transactions on Magnetics
Publication date: Feb 2018, volume: 54, issue:2, pages: 1 - 15
Publisher: IEEE
 
» Efficient Decoupling Capacitor Placement Based on Driving Point Impedance
Abstract:
With rapidly increasing switching speeds and surge current requirements, placement of local decoupling capacitors is becoming critically important in high-speed low-power designs. In this paper, utilizing the driving-point impedance (viewed from the device pin) as a metric, a new method is presented for the placement of decoupling capacitors in parallel-plate power ground pairs of high-speed circuits. In the proposed approach, instead of using the traditional trial-and-error method to identify an appropriate placement distance, the process is formulated in the form of a transcendental function. The resulting function is solved using Newton–Raphson (N-R) iterations to give a direct solution for the distance. Also, an analytical representation based on Hankel functions for the driving point impedance and its derivatives is developed to speed up the N-R iterations. The proposed method is validated by comparing the results with the full-wave electromagnetic simulations.
Autors: Ihsan Erdin;Ramachandra Achar;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Feb 2018, volume: 66, issue:2, pages: 669 - 677
Publisher: IEEE
 
» Efficient Distributed All-Pairs Algorithms: Management Using Optimal Cyclic Quorums
Abstract:
All Pairs problems occur in many research fields. The all-pairs problem requires all data elements to be paired with all other data elements. With the advent of new data intensive big data applications and increase in data size, methods to reduce memory foot print and distribute to work equally across compute nodes are needed. In this paper, we propose cyclic quorum sets for all-pairs algorithm computations to reduce memory foot print. We show that the cyclic quorum sets have a unique all-pairs property that allows for minimal data replication. The cyclic quorums set based computing requires only size memory, up to 50 percent smaller than the dual array implementations proposed earlier, and significantly smaller than solutions requiring all data in each node. Computation can be distributed efficiently and more importantly and are communication-less after initial data distribution, which is a huge advantage in minimizing computation time. Scaling from 16 to 512 cores (1 to 32 compute nodes), our application experiments on a real dataset demonstrated scalability with greater than 150x (super-linear) speedup with less than 1/4th the memory usage per node in our experiments.
Autors: Cory James Kleinheksel;Arun K. Somani;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Feb 2018, volume: 29, issue:2, pages: 391 - 404
Publisher: IEEE
 
» Efficient Modeling and Analysis of the Multiple Air Hole Effect in Substrate-Integrated Waveguide
Abstract:
A wide spectrum of potential applications using substrate-integrated waveguide (SIW) technologies in conjunction with air hole regions is introduced, and an efficient analysis method to cope with the multiple air hole effect in the SIW is proposed where we present the generalized wave equation satisfying the boundary and phase matching conditions to solve the multiple air interface problem, which provides highly accurate dispersion characteristics over the whole frequency band. The proposed approach is compared with a commercial software and verified by measurement results from the fabricated samples using Taconic/RF30-7H substrate, and is confirmed to give excellent agreement. Hence, the proposed method is effective for optimum design of SIW circuits for the purpose of low-loss and broadband applications.
Autors: Jin-Yang Kim;Dong-Wan Chun;Hai-Young Lee;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Feb 2018, volume: 28, issue:2, pages: 93 - 95
Publisher: IEEE
 
» Efficient Receive Antenna Selection for Pre-Coding Aided Spatial Modulation
Abstract:
Developed from the recently emerged pre-coding aided spatial modulation (PSM) concept, a class of efficient receives antenna selection (ERAS) techniques are devised. Aiming at approaching the optimal RAS performance in context of the PAM system, we derive the upper bound performance of RAS-PAM in two different ways, by utilizing the condition number and eigenvalue and Wishart distribution feature for the channel matrix. Our performance results demonstrate that the proposed ERAS techniques are capable of effectively improving the transmission performance in comparison with conventional RAS-PSM systems.
Autors: Peibo Wen;Xu He;Yue Xiao;Ping Yang;Rong Shi;Ke Deng;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 416 - 419
Publisher: IEEE
 
» Efficient Recommendation of Aggregate Data Visualizations
Abstract:
Data visualization is a common and effective technique for data exploration. However, for complex data, it is infeasible for an analyst to manually generate and browse all possible visualizations for insights. This observation motivated the need for automated solutions that can effectively recommend such visualizations. The main idea underlying those solutions is to evaluate the utility of all possible visualizations and then recommend the top-k visualizations. This process incurs high data processing cost, that is further aggravated by the presence of numerical dimensional attributes. To address that challenge, we propose novel view recommendation schemes, which incorporate a hybrid multi-objective utility function that captures the impact of numerical dimension attributes. Our first scheme, Multi-Objective View Recommendation for Data Exploration (MuVE), adopts an incremental evaluation of our multi-objective utility function, which allows pruning of a large number of low-utility views and avoids unnecessary objective evaluations. Our second scheme, upper MuVE (uMuVE), further improves the pruning power by setting the upper bounds on the utility of views and allowing interleaved processing of views, at the expense of increased memory usage. Finally, our third scheme, Memory-aware uMuVE (MuMuVE), provides pruning power close to that of uMuVE, while keeping memory usage within a pre-specified limit.
Autors: Humaira Ehsan;Mohamed A. Sharaf;Panos K. Chrysanthis;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Feb 2018, volume: 30, issue:2, pages: 263 - 277
Publisher: IEEE
 

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