Electrical and Electronics Engineering publications abstract of: 01-2018 sorted by title, page: 2

» A Reconfigurable LDPC Decoder Optimized for 802.11n/ac Applications
Abstract:
This paper presents a high data-rate low-density parity-check (LDPC) decoder, suitable for the 802.11n/ac (WiFi) standard. The innovative features of the proposed decoder relate to the decoding algorithms and the interconnection between the processing elements. The reduction of the hardware complexity of decoders based on the min-sum (MS) algorithms comes at the cost of performance degradation, especially at high-noise regions. We introduce more accurate approximations of the log-sum-product algorithm that also operate well for low signal-to-noise ratio values. Telecommunication standards, including WiFi, support more than one quasi-cyclic LDPC codes of different characteristics, such as codeword length and code rate. A proposed design technique derives networks, capable of supporting a variety of codes and efficiently realizing connectivity between a variable number of processing units, with a relatively small hardware overhead over the single-code case. As a demonstration of the proposed technique, we implemented a reconfigurable network based on barrel rotators, suitable for LDPC decoders compatible with WiFi standard. Our approach achieves low complexity and high clock frequency, compared with related prior works. A 90-nm application-specified integrated circuit implementation of the proposed high-parallel WiFi decoder occupies 4.88 mm2 and achieves an information throughput rate of 4.5 Gbit/s at a clock frequency of 555 MHz.
Autors: Ioannis Tsatsaragkos;Vassilis Paliouras;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jan 2018, volume: 26, issue:1, pages: 182 - 195
Publisher: IEEE
 
» A Reconfigurable Streaming Deep Convolutional Neural Network Accelerator for Internet of Things
Abstract:
Convolutional neural network (CNN) offers significant accuracy in image detection. To implement image detection using CNN in the Internet of Things (IoT) devices, a streaming hardware accelerator is proposed. The proposed accelerator optimizes the energy efficiency by avoiding unnecessary data movement. With unique filter decomposition technique, the accelerator can support arbitrary convolution window size. In addition, max-pooling function can be computed in parallel with convolution by using separate pooling unit, thus achieving throughput improvement. A prototype accelerator was implemented in TSMC 65-nm technology with a core size of 5 mm2. The accelerator can support major CNNs and achieve 152GOPS peak throughput and 434GOPS/W energy efficiency at 350 mW, making it a promising hardware accelerator for intelligent IoT devices.
Autors: Li Du;Yuan Du;Yilei Li;Junjie Su;Yen-Cheng Kuan;Chun-Chen Liu;Mau-Chung Frank Chang;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jan 2018, volume: 65, issue:1, pages: 198 - 208
Publisher: IEEE
 
» A Recursive Algorithm for Wideband Temporal Spectrum Sensing
Abstract:
Wideband spectrum sensing techniques determine which portions of a given spectrum band are occupied or idle in the frequency domain. The idle portions represent spectrum holes that can potentially be exploited by secondary or unlicensed users. Existing methods for wideband sensing, however, do not take into account the temporal activity of the primary or licensed users within the spectrum band. We propose an algorithm that identifies primary user activity over a wide spectrum band and provides a statistical characterization of the primary user signals in the band. The algorithm applies hidden Markov modeling to a hierarchically partitioned representation of the spectrum band, together with a recursive tree search. Different from existing wideband sensing algorithms, the proposed wideband temporal sensing method is able to accurately detect spectrum holes even in the presence of bursting primary user signals. Moreover, the hidden Markov modeling of the primary user signals enables the accurate detection and the prediction of primary user activity over time. Numerical results demonstrate the significant performance gain of the proposed algorithm over existing wideband spectrum sensing algorithms, particularly in the presence of low duty-cycle primary user signals.
Autors: Joseph M. Bruno;Brian L. Mark;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2018, volume: 66, issue:1, pages: 26 - 38
Publisher: IEEE
 
» A Reduced-Order Discontinuous Galerkin Method Based on POD for Electromagnetic Simulation
Abstract:
This paper is concerned with the design of a reduced-order discontinuous Galerkin (DG) method based on the proper orthogonal decomposition (POD) method for electromagnetic simulation. A centered flux approximation for surface integral and a second-order leap-frog scheme for advancing in time are applied in the classical DG method. The POD basis is created by the eigensystem of the correlation matrix, which is generated by the snapshot matrix whose columns are the snapshot vectors extracted from the high-fidelity DG simulation. The POD discontinuous Galerkin time-domain formulation with lower dimension and sufficiently high accuracy is established by applying a Galerkin projection for the semidiscrete DG scheme. The overall goal is to reduce the computational cost while maintaining an acceptable level of accuracy. Numerical experiments for electromagnetic problems illustrate the performance of the proposed reduction method.
Autors: Kun Li;Ting-Zhu Huang;Liang Li;Stéphane Lanteri;Li Xu;Bin Li;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 242 - 254
Publisher: IEEE
 
» A Reduced-Order Electrochemical Model of Li-Ion Batteries for Control and Estimation Applications
Abstract:
In this paper, a reduced-order electrochemical model of lithium-ion batteries is developed for control and estimation applications through analytical model order reduction based on a Galerkin projection method. The governing diffusion partial differential equations in the liquid and solid phases are approximated into low-order systems of ordinary differential equations while the physical meaning of all model parameters is preserved, allowing one to perform state and parameter estimation. The selection of basis functions for the Galerkin projection method and model order truncation is carefully determined based on analysis both in the frequency and time domains. With the reduced-order diffusion models in the liquid and solid phases, an extended single particle model incorporating the electrolyte dynamics is developed. The model is then validated against the experimental data gathered from two batteries with different chemistries (lithium nickel manganese cobalt oxide/graphite and lithium iron phosphate oxide/graphite) at different input conditions. Results show that the reduced-order model agrees very well with experimental data at various conditions. Meanwhile, it can be simulated thousands of times faster than the real time, making it suitable for long-term-life simulation, control, and estimation applications.
Autors: Guodong Fan;Xiaoyu Li;Marcello Canova;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2018, volume: 67, issue:1, pages: 76 - 91
Publisher: IEEE
 
» A Reliable and Reversible Image Privacy Protection Based on False Colors
Abstract:
Protection of visual privacy has become an indispensable component of video surveillance systems due to pervasive use of video cameras for surveillance purposes. In this paper, we propose two fully reversible privacy protection schemes implemented within the JPEG architecture. In both schemes, privacy protection is accomplished by using false colors with the first scheme being adaptable to other privacy protection filters while the second is false color-specific. Both schemes support either a lossless mode in which the original unprotected content can be fully extracted or a lossy mode, which limits file size while still maintaining intelligibility. Our method is not region-of-interest (ROI)-based and can be applied on entire frames without compromising intelligibility. This frees the user from having to define ROIs and improves security as tracking ROIs under dynamic content may fail, exposing sensitive information. Our experimental results indicate the favorability of our method over other commonly used solutions to protect visual privacy.
Autors: Serdar Çiftçi;Ahmet Oğuz Akyüz;Touradj Ebrahimi;
Appeared in: IEEE Transactions on Multimedia
Publication date: Jan 2018, volume: 20, issue:1, pages: 68 - 81
Publisher: IEEE
 
» A Repetitive Inductive Pulsed Power Supply Circuit Topology Based on HTSPPT
Abstract:
Inductive energy storage for pulsed power supplies is considered to have great potential because its energy density is 1 order of magnitude higher than that of capacitive one. Associating with the superconducting technology and the STRETCH meat grinder circuit, which proposed by the Institute of Advanced Technology, a superconducting inductive pulsed power supply (SPPS) circuit has been proposed by using an air-core high-temperature superconducting pulsed power transformer (HTSPPT) in our previous study. It can not only recapture the energy in the leakage flux and slow down the current change in inductors by using a capacitor, but also reduce the coil loss and the power requirement of the primary source by using superconducting inductors. However, it can be found that the SPPS may generate a large residual current during the discharging phase, which results in an adverse influence on the working frequency and the energy transfer efficiency of the whole system. This paper proposes a modified circuit based on the bridge current switching circuit and HTSPPT. The main principle of the circuit is that the recaptured energy in the capacitor and the residual energy in the secondary are used to precharge the primary inductor for the next cycle, which shortens the charging time, generates continuous current pulses, and improves the energy transfer efficiency. The procedure of the repetitive SPPS is analyzed in detail, and simulations are carried out to explain how the circuit works clearly.
Autors: Haitao Li;Yadong Zhang;Cunshan Zhang;Mingliang Gao;Yunzhu An;Tao Zhang;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2018, volume: 46, issue:1, pages: 134 - 139
Publisher: IEEE
 
» A Resistor-Based Temperature Sensor With a 0.13 pJ $cdot$ K2 Resolution FoM
Abstract:
This paper describes a high-resolution energy-efficient CMOS temperature sensor, intended for the temperature compensation of MEMS/quartz frequency references. The sensor is based on silicided poly-silicon thermistors, which are embedded in a Wien-bridge RC filter. When driven at a fixed frequency, the filter exhibits a temperature-dependent phase shift, which is digitized by an energy-efficient continuous-time phase-domain delta-sigma modulator. Implemented in a 0.18- CMOS technology, the sensor draws 87 from a 1.8 V supply and achieves a resolution of 410 in a 5-ms conversion time. This translates into a state-of-the-art resolution figure-of-merit of 0.13 pJ K2. When packaged in ceramic, the sensor achieves an inaccuracy of 0.2 °C (3 from −40 °C to 85 °C after a single-point calibration and a correction for systematic nonlinearity. This can be reduced to ±0.03 °C (3 after a first-order fit. In addition, the sensor exhibits low 1/ noise and packaging shift.
Autors: Sining Pan;Yanquan Luo;Saleh Heidary Shalmany;Kofi A. A. Makinwa;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2018, volume: 53, issue:1, pages: 164 - 173
Publisher: IEEE
 
» A Robust Dynamic Edge Network Architecture for the Internet of Things
Abstract:
A massive number of devices are expected to fulfill the missions of sensing, processing and control in cyber-physical IoT systems with new applications and connectivity requirements. In this context, scarce spectrum resources must accommodate high traffic volume with stringent requirements of low latency, high reliability, and energy efficiency. Conventional centralized network architectures may not be able to fulfill these requirements due to congestion in backhaul links. This article presents a novel design of an RDNA for IoT that leverages the latest advances of mobile devices (e.g., their capability to act as access points, storing and computing capabilities) to dynamically harvest unused resources and mitigate network congestion. However, traffic dynamics may compromise the availability of terminal access points and channels, and thus network connectivity. The proposed design embraces solutions at the physical, access, networking, application, and business layers to improve network robustness. The high density of mobile devices provides alternatives for close connectivity, reducing interference and latency, and thus increasing reliability and energy efficiency. Moreover, the computing capabilities of mobile devices project smartness onto the edge, which is desirable for autonomous and intelligent decision making. A case study is included to illustrate the performance of RDNA. Potential applications of this architecture in the context of IoT are outlined. Finally, some challenges for future research are presented.
Autors: Beatriz Lorenzo;Juan Garcia-Rois;Xuanheng Li;Javier Gonzalez-Castano;Yuguang Fang;
Appeared in: IEEE Network
Publication date: Jan 2018, volume: 32, issue:1, pages: 8 - 15
Publisher: IEEE
 
» A ROIC for Diode Uncooled IRFPA With Hybrid Non-Uniformity Compensation Technique
Abstract:
A CMOS readout integrated circuit with non-uniformity calibration for diode uncooled infrared focal plane array (IRFPA) is presented in this paper. Pixel signals are sampled and held by a capacitor, eliminating the extra current of the reference pixel. We propose a new transconductance amplifier with offset cancellation structure, utilizing output offset voltage storage. A novel 8-b current splitting DAC array is proposed in this paper. With the help of an off-chip ADC, the bias current of each pixel can be adjusted by DAC array, calibrating the non-uniformity of the IRFPA. The proposed circuit with 32 readout channels is fabricated using a 0.35- standard CMOS process. The measured results show that the average output offset voltages are 600 and 40 mV before and after calibration, respectively. The non-uniformity calibration technique has been proven very effective with 95% offset decrement, and this paper is especially suitable for large-scale image sensor.
Autors: Gongyuan Zhao;Mao Ye;Kai Hu;Yiqiang Zhao;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 501 - 507
Publisher: IEEE
 
» A Rotational Actuator Using a Thermomagnetic-Induced Magnetic Force Interaction
Abstract:
In this paper, we demonstrate a rotational actuator using a thermomagnetic-induced magnetic force interaction. The actuator consists of a magnetic rotary beam, stainless-steel bearing, mechanical frame, thermomagnetic Gadolinium sheets, and thermoelectric generators (TEGs). Experimental results show that applying a sequence of currents to the TEGs successfully produces sequential magnetic forces. Consequently, these sequential magnetic forces rotate the beam for revolutions. When applying a sequence set of currents of −0.5 and 1.3 A, the maximum rotation speed and maximum stall torque of the actuator is 3.81 rpm and Nm, respectively. Most importantly, the operating temperatures of other thermomagnetic (and electrothermal) actuators are usually high, but the operating temperature of our actuator is approximately room temperature (13 °C–27 °C). Therefore, our actuators have more practical applications. According to the above-mentioned features, we believe our actuator is an important alternative approach to developing future rotational actuators and motors.
Autors: Chih-Cheng Cheng;Tien-Kan Chung;Chin-Chung Chen;Hsin-Min Wang;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2018, volume: 54, issue:1, pages: 1 - 8
Publisher: IEEE
 
» A Semantic-Middleware-Supported Receding Horizon Optimal Power Flow in Energy Grids
Abstract:
Energy management in electric grids with multiple energy sources, generators, storage devices, and interacting loads along with their complex behaviors requires grid wide control. Communication infrastructure that aggregates information from heterogeneous devices in the electric grid making the applications completely independent of physical connectivity is essential for building in the context of control applications. This investigation presents a semantic middleware that is used to implement a receding-horizon-based optimal power flow (OPF) in smart grids. The presence of renewable energy sources, storage systems, and loads dispersed all along the grid necessitates the use of grid wide control and a communication infrastructure to support it. To this extent, the proposed middleware will serve as the basis for representing various components of the power grid. It is enriched with intelligence by semantic annotation and ontologies that provide situation awareness and context discovery. The middleware deployment is demonstrated by implementing the receding horizon OPF in a network in Steinkjer, Norway. Our results demonstrate the advantages of both the middleware and the algorithm. Furthermore, the results prove the added flexibility obtained in the grid due to the addition of renewable energy and storage systems. The significant advantage of the proposed approach is that the real-time monitoring infrastructure is used for improving the flexibility, reliability, and efficiency of the grid.
Autors: Alessio Maffei;Seshadhri Srinivasan;Pedro Castillejo;José Fernán Martínez;Luigi Iannelli;Eilert Bjerkan;Luigi Glielmo;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 35 - 46
Publisher: IEEE
 
» A Semi-Anaytical Model for the Analysis of a Permanent Magnet Tubular Linear Generator
Abstract:
In this paper, the authors introduce a semianalytical model for the analysis and the design of a permanent magnet (PM) tubular linear generator intended for electrical energy generation from sea waves. The translator of the analyzed machine is constituted by axially magnetized ferrite PMs with alternating polarity and soft magnetic pole pieces in between; a two-pole, double-layer, three-phase winding is located in the slots of the stator. The presented model, based on the use of the Carter coefficient and of the Fourier transform in the direction of the motion, is able to take into account the end effects due to the finite length of the stator. The presence of slots and teeth is subsequently considered by some postprocessing calculation carried on the results of the semianalytical model. Comparison with a finite element analysis and measurements taken on a prototype has been performed to validate the presented model. The model can be easily extended to other translator typologies, e.g., to air core translator with Halbach array of NdFeB PMs.
Autors: Antonino Musolino;Marco Raugi;Rocco Rizzo;Luca Sani;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 204 - 212
Publisher: IEEE
 
» A Series Solution for TE Electromagnetic Scattering by Arbitrary-Shaped Multilayer Cylinders
Abstract:
We previously introduced a simple and fast method for computing the scattered field when a TM wave is incident on an arbitrary-shaped multilayer cylindrical object. Here, we propose a modification of this method for the TE illumination case. According to this approach, the magnetic field at each layer is expressed as a series of cylindrical functions with unknown coefficients. These coefficients are determined through the solution of a linear system of equations that is obtained by first imposing the boundary conditions, then expressing cylindrical functions as Fourier series on each boundary, and using the orthogonality of complex exponentials. Numerical simulations show that the proposed modification for the TE case is also an efficient alternative numerical technique.
Autors: Birol Aslanyürek;Tolga Ulaş Gürbüz;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Jan 2018, volume: 17, issue:1, pages: 38 - 41
Publisher: IEEE
 
» A Shadow-Overlapping Algorithm for Estimating Building Heights From VHR Satellite Images
Abstract:
Building height is a key geometric attribute for generating 3-D building models. We propose a novel four-stage approach for automated estimation of building heights from their shadows in very high resolution (VHR) multispectral images. First, a building’s actual shadow regions are detected by applying ratio-band algorithm to the VHR image. Second, 2-D building footprint geometries are identified using graph theory and morphological fuzzy processing techniques. Third, artificial shadow regions are simulated using the identified building footprint and solar information in the image metadata at predefined height increments. Finally, the difference between the actual and simulated shadow regions at every height increment is computed using Jaccard similarity coefficient. The estimated building height corresponds to the height of the simulated shadow region that resulted in the maximum value for Jaccard index. The algorithm is tested on seven urban sites in Cardiff, U.K. with various levels of morphological complexity. Our method outperforms the past attempts, and the mean error is reduced by at least 21%.
Autors: Nada Kadhim;Monjur Mourshed;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jan 2018, volume: 15, issue:1, pages: 8 - 12
Publisher: IEEE
 
» A Shared Network Access Business Model for Distribution Networks
Abstract:
This letter proposes a new business model for distribution network operators (DNOs)—shared network access (SNA), aiming to integrate flexible demand in a cost-effective manner. The SNA scheme incentivises the incumbent DNOs to give up its exclusive access to the network, leasing the spare capacity or back up capacity to a licensed independent party. The ownership of assets will be retained by the incumbent DNO while competition will be introduced in the operation of the spare capacity. The independent parties who have license for SNA will act as secondary DNOs, tapping into the spare capacity in the network to provide flexible network services for flexible generation and demand, thus substantially reduce the network access cost for flexibility. This paper quantifies the potential benefit of mobilizing spare capacity for flexibility network usage and discusses how the proposed business model can capture such value for each player. The results demonstrate that the competition brought by the proposed SNA can take advantage of the unused capacities in the existing network assets and be able to substantially increase their capability in integrating flexible demand and generation.
Autors: Ran Li;Zhipeng Zhang;Furong Li;Petri Ahokangas;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 1082 - 1084
Publisher: IEEE
 
» A Silent Microwave Drill for Deep Holes in Concrete
Abstract:
This paper presents a mechanically assisted microwave drill (MWD) capable of drilling 26-cm-deep 12-mm-diameter holes in concrete. This record significantly extends the inherent /4-depth capability (~1.5 cm at 2.45 GHz) of the basic MWD scheme. Compared with conventional mechanical drills, this MWD is characterized by a relatively silent and vibration-free operation, but its drilling speed is yet slower than 1 cm/min. This paper reviews the fundamental MWD mechanism (utilizing localized microwave heating and thermal-runaway instability), and extends it for deeper holes by also using the coaxial applicator as a slowly rotating hollow reamer to remove the debris. The MWD prototype is introduced, including its adaptive impedance matching and remote-operation features, and its experimental results are presented. Theoretical and practical MWD aspects are discussed, and potential developments are indicated (e.g., for faster drilling and iron-rebar cutting). The present MWD performance can be useful for specific applications which critically require silent drilling operations in concrete.
Autors: Eli Jerby;Yuri Nerovny;Yehuda Meir;Or Korin;Ron Peleg;Yariv Shamir;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 522 - 529
Publisher: IEEE
 
» A Simple Coaxial to Circular Waveguide OMT for Low-Power Dual-Polarized Antenna Applications
Abstract:
A simple design for an orthomode transducer (OMT) is proposed for low-power antenna applications, such as receiver antennas as well as laboratory testing antennas. The design exploits detuning pins to enable enlarging the higher order mode-free bandwidth in an asymmetric configuration without compromising the port isolation. The design guidelines are presented for a scalable design. Moreover, the design is optimized to utilize all the single-mode operation bandwidth of the circular waveguide, covering the satellite communications band in North America (i.e., from 11.7 to 14.2 GHz). The presented OMT features a port coupling level below −34 dB. The measurement results are in a very good agreement with the full-wave analysis simulations.
Autors: Mohamed A. Moharram;Abdelhady Mahmoud;Ahmed A. Kishk;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 109 - 115
Publisher: IEEE
 
» A Simple Measurement Technique for Accurate Bistatic Retrodirective Radiation Pattern Calculation Based on the Active Element Pattern Method
Abstract:
This communication presents a new method for calculating bistatic responses from retrodirective arrays when only monostatic measurement data are available. The proposed approach offers considerable simplification to the measurement facilities required for retrodirective array characterization, since bistatic measurements are significantly more complicated to perform in comparison with monostatic measurements. The method involves making some minor changes to the monostatic measurement configuration, enabling the capture of active element patterns with magnitude and phase data, and combining these with a new expression to obtain the bistatic calculation. Very close agreement has been obtained when compared to actual measured bistatic responses of a ten element retrodirective patch array. In particular, the predicted beam position from the new method is within 0.25° at 40° scan angle, compared to a disagreement of 1.5° using previously reported methods.
Autors: N. B. Buchanan;V. F. Fusco;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 472 - 475
Publisher: IEEE
 
» A Simple Planar Dual-Band Bandpass Filter With Multiple Transmission Poles and Zeros
Abstract:
A simple and planar design structure for dual-band bandpass filter (BPF) with multiple transmission poles and zeros is proposed in this brief. According to frequency response transformation, two passbands are realized on both sides of the operation frequency. Sharp selectivity and high isolation level with eight transmission poles and seven transmission zeros are achieved just by employing three-section coupled lines and three short-circuit stubs. Besides, the analytical (closed-form) extraction process for the transmission poles and zeros of the proposed dual-band BPF is presented based on the rigorous scattering-parameters theory and the even- and odd-mode analysis method. A prototype for the dual-band BPF with 3-dB fractional bandwidth of 41.1% and 19.0% is designed and fabricated. The measured and simulated results are in good agreement to verify the validity of the proposed design principle.
Autors: Yongle Wu;Liwei Cui;Zheng Zhuang;Weimin Wang;Yuanan Liu;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2018, volume: 65, issue:1, pages: 56 - 60
Publisher: IEEE
 
» A Single-Shot Approach to Lossy Source Coding Under Logarithmic Loss
Abstract:
This paper considers the problem of lossy source coding with a specific distortion measure: logarithmic loss. The focus of this paper is on the single-shot approach, which exposes crisply the connection between lossless source coding with list decoding and lossy source coding with log-loss. Fixed-length and variable-length bounds are presented. Fixed-length bounds include the single-shot fundamental limit for average as well as excess distortion. Variable-length bounds include the single-shot fundamental limit for average as well as excess length. Two multi-terminal problems are addressed: coding with side information (Wyner–Ziv) and multiple descriptions coding. In both the cases, the application of the Shannon–McMillan theorem to the single-shot bounds yields the rate-distortion function and the rate distortion-region for stationary ergodic sources.
Autors: Yanina Y. Shkel;Sergio Verdú;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2018, volume: 64, issue:1, pages: 129 - 147
Publisher: IEEE
 
» A Single-Stage LED Driver With High-Performance Primary-Side-Regulated Characteristic
Abstract:
A traditional flyback LED driver is limited by its low performance, which usually does not meet the power factor (PF) and total harmonic distortion requirements according to Energy Star or IEC61000-3-2. The control loop from the secondary side to the primary side has low reliability and employs more components, which reduces the power density of the system and increases the cost. In this brief, based on single-stage single ended primary inductor converter (SEPIC) and flyback converter, a primary-side-regulated LED driver is proposed to improve the performance of the system. Working in DCM, the SEPIC circuit realizes the PF correction naturally. For the flyback converter, the proposed primary-side-regulated method improves the power density and guarantees accurate control of the output current. A 100-W prototype based on SEPIC-flyback was built to verify the analysis and the experimental results coincided with the analysis results satisfactorily.
Autors: Yijie Wang;Shu Zhang;J. Marcos Alonso;Xiaosheng Liu;Dianguo Xu;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2018, volume: 65, issue:1, pages: 76 - 80
Publisher: IEEE
 
» A Small Symmetric-Slit-Shaped and Annular Slotted BeiDou Antenna With Stable Phase Center
Abstract:
A small annular slotted BeiDou antenna with symmetric slits is proposed for applications in Compass Navigation Satellite System of China. Two symmetric annular slots with tabs are embedded onto a circular microstrip patch for circularly polarized (CP) radiation. Good CP radiation and impedance matching can be achieved by reasonably adjusting the radii of the annular slots and the position of the tabs. Six pairs of symmetric slits are embedded along the radial direction of the circular patch to reduce antenna size. We achieve a total patch area reduction of 23.3% compared with the traditional tuning stub CP antenna. Owing to the symmetric structure, the deviation of the phase center is only about 1.76 mm at the central frequency. The measured results agree well with the simulated results.
Autors: Ke-Ke Zheng;Qing-Xin Chu;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Jan 2018, volume: 17, issue:1, pages: 146 - 149
Publisher: IEEE
 
» A Sparse Minimal-Order Dynamic Model of Power Networks Based on dq0 Signals
Abstract:
Today the dq0 reference frame is mainly used for modeling and control of traditional electric machines and small power sources. A current challenge is to merge various dq0-based models appearing in recent literature to obtain a complete model of a large power system. To this end, in this paper we propose a model describing the dynamics of large transmission networks based on dq0 quantities. The proposed model is based on a standard network topology, uses sparse system matrices, and is of minimal order. We also demonstrate how this model may be used to construct a small-signal description of a complete system that includes the transmission network, generators, and loads. Results are illustrated on the basis of a long transmission line, and using the 118-bus test case network. This paper is accompanied by a free software package.
Autors: Juri Belikov;Yoash Levron;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 1059 - 1067
Publisher: IEEE
 
» A Spectral Graph Theoretic Approach for Monitoring Multivariate Time Series Data From Complex Dynamical Processes
Abstract:
The objective of this paper is to monitor complex process dynamics manifest in multivariate (multidimensional) time series data using a spectral (algebraic) graph theoretic approach. We test the hypothesis that the spectral graph-based topological invariants detect incipient process drifts earlier [lower average run length (ARL1)] and with higher fidelity (consistency of detection) when compared with the conventional statistics-based approaches. The presented approach maps a multidimensional sensor data stream (visualize as time and as the number of sensors) as an unweighted and undirected network graph , indexed by its vertices and edges , i.e., . The rationale is that the graph-based topological invariants are surrogate representatives of the system state. We compare the monitoring performance of spectral graph theoretic invariants with conventional statistical features in an exponentially weighted moving average control chart setting. The practical utility of the approach is substantiated in the context of process monitoring in two advanced manufacturing scenarios, namely, ultraprecision machining (UPM) and semiconductor chemical mechanical planarization. These studies corroborate the hypothesis that graph theoretic invariants, when used as monitoring statistics, lead to lower ARL1 and more consistent detections in contrast to conventional statistical features. F- r instance, in the UPM case, the fault detection delay using graph theoretic invariants is less than 160 ms, compared with over 8 s of delay with statistical features.

Note to Practitioners—This paper addresses the critical problem of capturing process drifts from multidimensional (multisensor) data. The novelty of this paper is the development of a graph theoretic approach that combines signals from multiple in situ sensors for detecting abnormal process drifts. We show that this approach, which invokes graph-based topological invariants instead of statistical feature mining, is capable of capturing process drifts at an earlier stage (in terms of detection delay or lower average run length) and higher consistency of detection than conventional statistical features. As a practical consequence of this research, the operator can track the status of a complex process in a tractable control chart setting with only two graph theoretic topological invariants, as opposed to complex black-box models involving several features.

Autors: Mohammad Samie Tootooni;Prahalad K. Rao;Chun-An Chou;Zhenyu James Kong;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2018, volume: 15, issue:1, pages: 127 - 144
Publisher: IEEE
 
» A Stabilized Complex LOBPCG Eigensolver for the Analysis of Moderately Lossy EM Structures
Abstract:
This letter proposes a stabilized locally optimal block preconditioned conjugate gradient method for computing selected eigenvalues for complex symmetric generalized non-Hermitian eigenproblems. Effectiveness of the presented approach is demonstrated for a moderately lossy dual-mode dielectric resonator, modeled using finite-element method with higher order elements.
Autors: Michal Rewienski;Adam Dziekonski;Adam Lamecki;Michal Mrozowski;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2018, volume: 28, issue:1, pages: 7 - 9
Publisher: IEEE
 
» A State Transition MIP Formulation for the Unit Commitment Problem
Abstract:
In this paper, we present the state-transition formulation for the unit commitment (UC) problem. This formulation uses new decision variables that capture the state transitions of the generators, instead of their on/off statuses. We show that this new approach produces a formulation which naturally includes valid inequalities, commonly used to strengthen other formulations. We demonstrate the performance of the state-transition formulation and observe that it leads to improved solution times especially in longer time-horizon instances. As an important consequence, the new formulation allows us to solve realistic instances in less than 12 minutes on an ordinary desktop PC, leading to a speed-up of a factor of almost two, in comparison to the nearest contender. Finally, we demonstrate the value of considering longer planning horizons in UC problems.
Autors: Semih Atakan;Guglielmo Lulli;Suvrajeet Sen;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 736 - 748
Publisher: IEEE
 
» A State-Space Approach to Modelling DC Distribution Systems
Abstract:
Many modelling methods for the analysis of dc distribution grids only consider monopolar configurations and do not allow for mutual couplings to be taken into account. The modelling method presented in this paper aims to deal with both of these issues. A state-space approach is chosen for its flexibility and computational speed. The derived approach can be applied to any dc distribution system regardless of its configuration and takes into account mutual couplings between phase conductors. Moreover, the state-space matrices can be derived in a programmatic manner. The derived model is verified empirically and by a reference model created in Simulink using PowerLib blocks. Subsequently, an illustrative system is analyzed, which shows the utility of the presented method in analyzing the dynamics of dc distribution systems. The presented method is especially useful for the analysis, design, and optimization of, for example, the stability and control systems of dc distribution systems.
Autors: Nils H. van der Blij;Laura M. Ramirez-Elizondo;Matthijs T. J. Spaan;Pavol Bauer;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 943 - 950
Publisher: IEEE
 
» A Stochastic Adaptive Robust Optimization Approach for the Generation and Transmission Expansion Planning
Abstract:
This paper proposes a stochastic adaptive robust optimization approach for the generation and transmission expansion planning problem. The problem is formulated under the perspective of a central planner, e.g., the transmission system operator, that aims at determining the generation and transmission expansion plans that minimize both the expansion and operation costs. This central planner builds the transmission facilities and promotes the building of the most suitable generating units among private profit-oriented investors. Uncertainties in the future peak demand and the future generation (fuel) cost are modeled using confidence bounds, while uncertainties in the demand variability and the production of stochastic units are modeled using a number of operating conditions. Results of an illustrative example and a case study based on the IEEE 118-bus test system show the effectiveness of the proposed approach.
Autors: Luis Baringo;Ana Baringo;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 792 - 802
Publisher: IEEE
 
» A Structured Sparse Subspace Learning Algorithm for Anomaly Detection in UAV Flight Data
Abstract:
Health status monitoring of flight-critical sensors is crucial to the flight safety of unmanned aerial vehicles (UAVs). While many flight data anomaly detection algorithms have been proposed, most do not consider data source information and cannot identify which data sources contribute most to the anomaly, hindering proper fault mitigation. To address this challenge, a structured sparse subspace learning (SSL) anomaly detection (SSSLAD) algorithm, which reformulates anomaly detection as a structured SSL problem, is proposed. A structured norm is imposed on the projection coefficients matrix to achieve structured sparsity and help identify anomaly sources. Utilizing an efficient optimization method based on Nesterov’s method and a subspace tracking approach considering temporal dependence, the computation is efficient. Experiments on real UAV flight data sets illustrate that the proposed SSSLAD algorithm can accurately and quickly detect and identify anomalous sources in flight data, outperforming state of art algorithms, both in terms of accuracy and speed.
Autors: Yongfu He;Yu Peng;Shaojun Wang;Datong Liu;Philip H. W. Leong;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2018, volume: 67, issue:1, pages: 90 - 100
Publisher: IEEE
 
» A Study of Endurance Issues in HfO2-Based Ferroelectric Field Effect Transistors: Charge Trapping and Trap Generation
Abstract:
Recent demonstration of aggressively scaled HfO2-based ferroelectric field effect transistors (FE-HfO2-FETs) has illustrated a pathway to fabricate FeFETs that enjoy COMS-compatibility, low power, fast switching speed, scalability, and long retention. One potential issue of this promising technology is its limited endurance, which has been attributed to the degradation of gate stack before the fatigue of polarization in the ferroelectric HfO2 layer. Some associated work has identified charge trapping and trap generation as key villains, but a clear understanding of two aforementioned underlining mechanisms is still missing. In this letter, we initiated this letter to investigate the roles of charge trapping and trap generation in causing endurance failure of FE-HfO2 FETs.
Autors: Nanbo Gong;Tso-Ping Ma;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2018, volume: 39, issue:1, pages: 15 - 18
Publisher: IEEE
 
» A Study of the Characteristics of a Deformable Antenna Based on Gas Discharge
Abstract:
This paper presents an introduction to a deformable plasma antenna excited by an alternating current power supply at a frequency of 12 kHz. The deformable discharge tube could be transformed into many types of shapes, such as a monopole, U-shape, loop, helix, or plane, by means of a simple mounting and rotating system. The characteristics of the antenna were studied for various discharge parameters and antenna shapes. Experimental results demonstrate that the antenna characteristics, such as impedance, radiation pattern, gain, and polarization, can be simply controlled by varying the discharge parameters and antenna shapes. Compared with a conventional plasma antenna made of hard materials, the reconfiguration scope of the deformable plasma antenna is considerably broader. Moreover, the antenna shape can be modified in a manner that is both flexible and easily implemented.
Autors: Jiansen Zhao;Xinqiang Chen;Shengzheng Wang;Wei Liu;Baoxian Ji;Yue Liu;Zhen Sun;Tie Xu;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 59 - 70
Publisher: IEEE
 
» A Study of the Fast Neutron Response of a Single-Crystal Diamond Detector at High Temperatures
Abstract:
The fast neutron response of a single-crystal diamond (SCD) detector was studied up to 300 °C. The SCD detector was fabricated using a substrate with premetallization treatments for obtaining oxygen terminated surfaces. The electrical contacts to the detector were provided by Cr/Au metallization. The performance of the fabricated detector was investigated using leakage current versus bias voltage (I–V) measurements and using pulse height spectra measurements with 5.5 MeV alphas and 14 MeV fast neutrons. The leakage current was observed to be about 400–600 pA at a field of 1 V/. From the full-width half-maximum of the alpha peak at 5.5 MeV, an energy resolution of about 2.1 ± 0.1% was estimated. The fast neutron response measurements were carried out using a 14 MeV deuterium–tritium neutron source. No measurable degradation of the detector performance was observed up to the maximum studied temperature of 300 °C. The neutron spectrum obtained at 300 °C showed a well-defined peak at 8.5 MeV due to the 12C(n, Be reaction which was the same as that observed at room temperature. Considering the total integrated counts, the detector sensitivity was observed to be count per neutron. The results presented in this paper demonstrate for the first time the high temperature operation of an SCD detector up to 300 °C. These results also suggest that such SCD detectors could be used at higher temperatures for neutron- diagnostics in the future fusion plasma facilities such as International Thermonuclear Experimental Reactor.
Autors: Amit Kumar;Anita Topkar;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Jan 2018, volume: 65, issue:1, pages: 630 - 635
Publisher: IEEE
 
» A Sub-Microwatt Class-AB Super Buffer: Frequency Compensation for Settling-Time Improvement
Abstract:
This brief presents a frequency compensation technique to improve the settling time in driving moderate capacitive load (10–20 pF) of a low-power (<1 ) class-AB super buffer, wherein previously reported super buffers exhibit poor stability performance. From post-layout simulations in a 0.18- CMOS process, the proposed super buffer—while driving a 10-pF load and consuming less than 1 of quiescent current from a 1.2-V supply voltage—achieves a factor of 1.8 (positive output direction) and 5.1 (negative output direction) reduction in the settling time compared to before compensation. We also validated the proposed technique through the measurements of a super buffer built on a protoboard with commercial discrete MOS transistors.
Autors: Pakorn Prasopsin;Woradorn Wattanapanitch;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2018, volume: 65, issue:1, pages: 26 - 30
Publisher: IEEE
 
» A Subthreshold Baseband Processor Core Design With Custom Modules and Cells for Passive RFID Tags
Abstract:
Sophisticated subthreshold passive radio frequency identification tag’s baseband processor (BBP) core design for ultralow-power Internet of Things end devices is presented in this paper. Custom logic cells and tailored logic architectures are applied to eliminate timing violations when the operating voltage is much lower than nominal level. For the consideration of limited availability of radio frequency power, power-aware scheme is applied to the key modules, including PIE decoding and command receiving. Furthermore, Galois linear feedback shift register and double-edge-triggered techniques help to improve clock efficiency and reduce the impact of frequency variation in data link portions. Importantly, a novel custom ratioed logic style is adopted in key modules to fundamentally speed up signals’ propagation at ultralow-voltage. The proposed BBP was fabricated in 90-nm CMOS as well as the regular design with the same function. It was also implemented in the tag chip’s fabrication. In measurement the proposed design indicates good robustness and is much more competent for subthreshold operation. It can operate below 0.3 V with power consumption below 130 nW.
Autors: Weiwei Shi;An Pan;Shi Yu;Chiu-Sing Choy;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jan 2018, volume: 37, issue:1, pages: 159 - 167
Publisher: IEEE
 
» A Successive Approximation Recursive Digital Low-Dropout Voltage Regulator With PD Compensation and Sub-LSB Duty Control
Abstract:
This paper presents a recursive digital low-dropout (RLDO) regulator that improves response time, quiescent power, and load regulation dynamic range over prior digital LDO designs by 1–2 orders of magnitude. The proposed RLDO enables a practical digital replacement to analog LDOs by using an SAR-like binary search algorithm in a coarse loop and a sub-LSB pulse width modulation duty control scheme in a fine loop. A proportional-derivative compensation scheme is employed to ensure stable operation independent of load current, the size of the output decoupling capacitor, and clock frequency. Implemented in 0.0023 mm2 in 65 nm CMOS, the 7-bit RLDO achieves, at a 0.5-V input, a response time of 15.1 ns with a figure of merit of 199.4 ps, along with stable operation across a 20 000 dynamic load range.
Autors: Loai G. Salem;Julian Warchall;Patrick P. Mercier;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2018, volume: 53, issue:1, pages: 35 - 49
Publisher: IEEE
 
» A Symmetry-Based Method for LiDAR Point Registration
Abstract:
LiDAR point registration is a key procedure for the acquisition of complete point cloud datasets. It has great significance for the fusion of multisource LiDAR data. In general, the widely used methods for LiDAR point registration can be categorized into three types: auxiliary methods, direct methods, and feature methods. However, for the registration of complex objects (e.g., stadium and tower), such methods may face varying degrees of technical problems owing to the unavailability of auxiliary data or targets, requirement of sufficient overlapping areas, and difficulty in feature extraction and matching. In the real world, numerous objects with extremely complicated geometric shapes have the characteristic of symmetry. This study focuses on complex objects with symmetry and tries to exploit their intrinsic symmetry characteristic in order to facilitate their point cloud registration. A symmetry-based method for LiDAR point registration is proposed, in which the general idea is to derive 3-D central axes from multisource point clouds, based on the symmetry of objects. The proposed method consists of six main steps: detection of rotational symmetry, adaptive point cloud slicing, central point extraction, central axis fitting, central axis matching, and orientation and positioning. Comparative experiments and quantitative evaluations are conducted. The experimental results indicate that the proposed framework can achieve satisfactory registration of objects with rotational symmetry.
Autors: Liang Cheng;Yang Wu;Song Chen;Wenwen Zong;Yi Yuan;Yuefan Sun;Qizhi Zhuang;Manchun Li;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2018, volume: 11, issue:1, pages: 285 - 299
Publisher: IEEE
 
» A Systematic Solution to Multi-Instrument Coregistration of High-Resolution Planetary Images to an Orthorectified Baseline
Abstract:
We address the problem of automatically coregistering planetary images to a common baseline, introducing a novel generic technique that achieves an unprecedented robustness to different image inputs, thus making batch-mode coregistration achievable without requiring the usual parameter tweaking. We introduce a novel image matching technique, which boosts matching performance even under the most strenuous circumstances, and experimentally demonstrate validation through an extensive experimental multi-instrument setup that includes images from eight high-resolution data sets of the Mars and the Moon. The technique is further tested in a batch-mode processing, in which approximately 1.6% of all high-resolution Martian imagery is coregistered to a common baseline.
Autors: Panagiotis Sidiropoulos;Jan-Peter Muller;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jan 2018, volume: 56, issue:1, pages: 78 - 92
Publisher: IEEE
 
» A Systems Theoretic Approach to the Security Threats in Cyber Physical Systems Applied to Stuxnet
Abstract:
Cyber physical systems (CPSs) are increasingly being adopted in a wide range of industries such as smart power grids. Even though the rapid proliferation of CPSs brings huge benefits to our society, it also provides potential attackers with many new opportunities to affect the physical world such as disrupting the services controlled by CPSs. Stuxnet is an example of such an attack that was designed to interrupt the Iranian nuclear program. In this paper, we show how the vulnerabilities exploited by Stuxnet could have been addressed at the design level. We utilize a system theoretic approach, based on prior research on system safety, that takes both physical and cyber components into account to analyze the threats exploited by Stuxnet. We conclude that such an approach is capable of identifying cyber threats towards CPSs at the design level and provide practical recommendations that CPS designers can utilize to design a more secure CPS.
Autors: Arash Nourian;Stuart Madnick;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Jan 2018, volume: 15, issue:1, pages: 2 - 13
Publisher: IEEE
 
» A Target-Free Automatic Self-Calibration Approach for Multibeam Laser Scanners
Abstract:
In this paper, a target-free automatic self-calibration approach for multibeam laser scanners is proposed. The proposed approach uses the isomorphism constraint among the laser scanner data to optimize the calibration parameters, uses the ambiguity judgment algorithm to solve the mismatch problem, and finally achieves the purpose of automatic calibration. The experimental results show that the accuracy of our algorithm is higher than that of the target-based calibration approach. The calibration process is automatic and fast.
Autors: Zheng Gong;Chenglu Wen;Cheng Wang;Jonathan Li;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2018, volume: 67, issue:1, pages: 238 - 240
Publisher: IEEE
 
» A Technique for Characterizing Ionization and Displacement Defects in NPN Transistors Induced by 1-MeV Electron Irradiation
Abstract:
In this paper, characteristics of damage defects in 3DG110 NPN transistors induced by 1-MeV electrons were investigated by deep-level transient spectroscopy (DLTS) with the various period widths and reverse biases. The curve slope corresponding to the ideality factor for the irradiated NPN transistor by 1-MeV electrons at different fluences does not vary with the emitter–base voltage. The oxide-trapped charge, interface traps, and displacement defect centers in the NPN transistor are detected by DLTS simultaneously. These results show that unlike Co-60 gamma ray and low-energy electrons with less than 170 keV which can cause only ionization damage, 1-MeV electrons can produce both ionization and displacement damage on Si BJTs. With decreasing period width of DLTS measurement, the height of ionization defect (including oxide-trapped charge and interface traps) peaks increases, while the height of the displacement defect (VO center) peak remains unchanged. Meanwhile, with increasing reverse biases, the position of ionization defect peaks moves to rightward, while the position of displacement peaks keeps unchanged. Moreover, based on the annealing experimental results, with increasing the annealing temperature and time, both the concentration and the energy levels for oxide-trapped charge, the energy level of interface traps obviously change, and the energy level of VO center does not change. These experimental results show DLTS can be used to identify the ionization and displacement defects in bipolar transistors accurately and conveniently.
Autors: Xingji Li;Jianqun Yang;Chaoming Liu;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Jan 2018, volume: 65, issue:1, pages: 539 - 544
Publisher: IEEE
 
» A Tensor-Based Holistic Edge Computing Optimization Framework for Internet of Things
Abstract:
Balancing the costs of different objectives in EC requires comprehensive and global analysis. This article investigates the holistic EC optimization problem for IoT. First, a triple-plane EC architecture for IoT is proposed including the edge device plane, edge server plane, and cloud plane, respectively, which is conducive to collaboratively accomplishing the EC applications. Then five tensor-based representation models are constructed to represent the complex relationships and resolve the heterogeneity of different devices. Afterward, we construct a generalized and holistic EC optimization model based on the constructed tensors including energy consumption, execution time, system reliability, and quality of experience. Finally, a customized optimization framework is proposed in which the optimization objectives can be arbitrarily combined according to practical applications. A case study is conducted to evaluate the performance of the proposed scheme; results demonstrate that it significantly outperforms the state-of-the-art cloud-assisted mobile computing scheme and holistic mobile cloud computing scheme.
Autors: Huazhong Liu;Laurence T. Yang;Man Lin;Dexiang Yin;Yimu Guo;
Appeared in: IEEE Network
Publication date: Jan 2018, volume: 32, issue:1, pages: 88 - 95
Publisher: IEEE
 
» A Tensor-Based Multiple Clustering Approach With Its Applications in Automation Systems
Abstract:
Multiple clustering analysis has the clear advantages to discover latent data pattern in big data from different views, so it has tremendous practical values in automation industries. However, most of current algorithms are difficult to group heterogeneous data to multiple clusterings according to the requirements of different applications. This paper presents a flexible multiple clustering analytic and service framework, and a novel tensor-based multiple clusterings (TMC) approach. Heterogeneous data objects in cyber-physical-social systems are first represented as low-order tensors and a weight tensor construction approach is proposed to measure the importance of attributes combinations in heterogeneous feature spaces. Then, a selective weighted tensor distance is explored to cluster tensorized data objects for different applications. This paper, through a real-world smart bike maintenance system, illustrates TMC and evaluates its clustering performance. Experimental results reveal TMC can obtain higher quality clustering results but with lower redundancies to meet different requirements of applications in automation systems.
Autors: Yaliang Zhao;Laurence T. Yang;Ronghao Zhang;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 283 - 291
Publisher: IEEE
 
» A Time-Based Receiver With 2-Tap Decision Feedback Equalizer for Single-Ended Mobile DRAM Interface
Abstract:
A time-based (TB) receiver (RX) with a 2-tap TB decision feedback equalizer (DFE) is proposed for mobile DRAM interface. The TB RX consists of a voltage-to-time converter (VTC), a TB DFE, and a time comparator. The VTC converts the RX input voltage to a time difference between two VTC outputs by using the difference in clock-to-Q delays between two latches with different input offset voltages. The TB DFE inserts an additional delay to one of the two VTC outputs and bypasses the other VTC output to increase the time opening. The time comparator makes a decision with the first arriving edge of the two outputs of the TB DFE. While the feedback loop delay must be less than 1 UI for proper operation in the conventional voltage-based DFE, the TB DFE allows the feedback loop delay up to 1.43 UI in this paper. A transmitter (TX) transmits a single-ended signal of 200-mV swing by using an n-over-n voltage-mode driver. The transceiver in a 65-nm CMOS process achieves a 12.5 Gb/s with a 0.8-V supply through a 15-inch FR-4 channel of 14-dB loss. The TX and RX chip consume 4.3 and 3.4 mA, respectively. The energy efficiency is 0.49 pJ/b.
Autors: Il-Min Yi;Min-Kyun Chae;Seok-Hun Hyun;Seung-Jun Bae;Jung-Hwan Choi;Seong-Jin Jang;Byungsub Kim;Jae-Yoon Sim;Hong-June Park;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2018, volume: 53, issue:1, pages: 144 - 154
Publisher: IEEE
 
» A Time-Efficient CMOS-Memristive Programmable Circuit Realizing Logic Functions in Generalized AND–XOR Structures
Abstract:
This paper describes a CMOS-memristive programmable logic device connected to CMOS XOR gates (mPLD-XOR) for realizing multioutput functions well suited for two-level {NAND, AND, NOR, OR}-XOR-based design. This structure is a generalized form of AND–XOR logic where any combination of NAND, AND, NOR, and OR, and literals can replace the and level. For mPLD-XOR, the computational delay, which is measured as the number of clock cycles, equals the maximum number of inputs to any output XOR gate of a function assuming that the number of XOR gates is large enough to calculate the outputs of the function simultaneously. The input levels of functions are implemented with novel programmable diode gates, which rely on the diode-like behavior of self-rectifying memristors, and the output levels of functions are realized with CMOS modulo-two counters. As an example, the circuit implementation of a 3-bit adder and a 3-bit multiplier are presented. The size and performance of the implemented circuits are estimated and compared with those of the equivalent circuits realized with stateful logic gates. Adding a feedback circuit to the mPLD-XOR allows the implementation of a multilevel XOR logic network with any combination of sums, products, XORs, and literals at the input of any XOR gate. The mPLD-XOR with feedback can reduce the size and number of computational steps (clock cycles) in realizing logic functions, which makes it well suited for use in communication and parallel computing systems where fast arithmetic operations are demanding.
Autors: Muayad J. Aljafar;Marek A. Perkowski;John M. Acken;Robin Tan;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jan 2018, volume: 26, issue:1, pages: 23 - 36
Publisher: IEEE
 
» A Tri-Slope Gate Driving GaN DC–DC Converter With Spurious Noise Compression and Ringing Suppression for Automotive Applications
Abstract:
Targeting on electromagnetic interference (EMI) regulation and ringing suppression issues in automotive applications, this paper presents a gallium nitride (GaN)-based dc–dc converter operating at 10 MHz. A spurious noise compression technique compresses and re-distributes spurious switching noise within a defined frequency sideband, achieving EMI noise reduction at main switching frequency and its harmonics. Meanwhile, a tri-slope gate driver is designed to control voltage and current slew rates of GaN switches for effective ringing suppression, which is adaptive to load and input voltage changes. Tailored for high switching frequency and high-efficiency operation, the dynamic level shifters achieve about 0.8-ns propagation delay and near-zero quiescent current. Fabricated in a 0.35-m Bipolar-CMOS-DMOS process, the converter accomplishes an EMI noise reduction of 40.5 dBV and suppresses ringing by 79.3%. The converter retains above 60% efficiency over 96.6% of its 6-W power range, with a peak efficiency of 85.5% at 1.5-W load.
Autors: Xugang Ke;Joseph Sankman;Yingping Chen;Lenian He;D. Brian Ma;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2018, volume: 53, issue:1, pages: 247 - 260
Publisher: IEEE
 
» A Two-level Traffic Light Control Strategy for Preventing Incident-Based Urban Traffic Congestion
Abstract:
This work designs a two-level strategy at signalized intersections for preventing incident-based urban traffic congestion by adopting additional traffic warning lights. The first-level one is a ban signal strategy that is used to stop the traffic flow driving toward some directions, and the second-level one is a warning signal strategy that gives traffic flow a recommendation of not driving to some directions. As a visual and mathematical formalism for modeling discrete-event dynamic systems, timed Petri nets are utilized to describe the cooperation between traffic lights and warning lights, and then verify their correctness. A two-way rectangular grid network is modeled via a cell transmission model. The effectiveness of the proposed two-level strategy is evaluated through simulations in the grid network. The results reveal the influences of some major parameters, such as the route-changing rates of vehicles, operation time interval of the proposed strategy, and traffic density of the traffic network on a congestion dissipation process. The results can be used to improve the state of the art in preventing urban road traffic congestion caused by incidents.
Autors: Liang Qi;MengChu Zhou;WenJing Luan;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2018, volume: 19, issue:1, pages: 13 - 24
Publisher: IEEE
 
» A Two-Phase Multiobjective Sparse Unmixing Approach for Hyperspectral Data
Abstract:
With the sparse unmixing becoming increasingly popular recently, some advanced regularization algorithms have been proposed for settling this problem. However, they are limited by their “decision ahead of solution” attribute, i.e., the regularization parameters must be preset before the solution is obtained. In this paper, the sparse unmixing problem is first formulated as a two-phase multiobjective problem. The first phase simultaneously minimizes the unmixing residuals and the number of estimated endmembers for automatically finding the real active endmembers from the spectral library. A decomposition-based endmember selection algorithm considering the gene exchange in the population is specially designed for better and quicker search of the decision space. This algorithm can obtain a set of nondominated solutions for better decision of the active endmembers, which are important for the subsequent calculation of the abundance matrix. The second phase concurrently minimizes the unmixing residuals and the total variation term for estimating a preferable abundance matrix. A local search strategy based on the multiplicative update rule is designed in the evolution process for better approximation of the Pareto front. The experimental results on the synthetic as well as the real data reveal that the proposed framework has a better performance in finding the real active endmembers and estimating their corresponding abundances than some advanced regularization algorithms.
Autors: Xiangming Jiang;Maoguo Gong;Hao Li;Mingyang Zhang;Jun Li;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jan 2018, volume: 56, issue:1, pages: 508 - 523
Publisher: IEEE
 
» A Two-Stage Quasi-Resonant Dual-Buck LED Driver With Digital Control Method
Abstract:
A two-stage quasi-resonant LED driver with a digital control method is proposed in this paper. The first stage of this converter is a boost circuit with a power factor correction function, and the second stage is a dual-buck circuit that works in a quasi-resonant zero voltage switching state. Because of the soft-switching characteristics of the converter, switching losses are reduced and efficiency is significantly improved. A digital control method is adopted to detect the peak value of inductor current and enhance system reliability. Moreover, because LEDs are always driven by a current source, a current loop is designed to maintain constant output current. IRS2104 is chosen as the drive chip and the microcontroller is AT90PWM216, which can improve the quality of the drive signals. The output of the converter is a square wave that drives two branches of antiparallel LEDs. A 60-W prototype was designed to demonstrate the theoretical analysis. The obtained power factor was as high as 0.987 and the efficiency reached 92.3%.
Autors: Yijie Wang;Shanshan Gao;Shu Zhang;Dianguo Xu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 787 - 795
Publisher: IEEE
 
» A Two-Step Sensing Circuit for the Hysteresis Loop Selector-Based Resistive Non-Volatile Memory Arrays
Abstract:
A high selectivity semiconductor selector is the key component in the ultra-high density and low power 3-D resistive non-volatile memory array. The state-of-art selectors suffer from various issues including low selectivity, high OFF current, and low ON current, which significantly limit the array size and performance. Recently, a hysteresis loop (HL) selector with the high selectivity, moderate ON voltage and large HL window was developed to address the high leakage current issue. In this brief, a two-step sensing scheme is proposed to minimize the read disturbance and sensing power. The proposed two-step sensing circuit could achieve 25-ns fast sensing speed with 3.92-uW low sensing power.
Autors: Kejie Huang;Wei He;Rong Zhao;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2018, volume: 65, issue:1, pages: 101 - 105
Publisher: IEEE
 
» A Utility-Aware Visual Approach for Anonymizing Multi-Attribute Tabular Data
Abstract:
Sharing data for public usage requires sanitization to prevent sensitive information from leaking. Previous studies have presented methods for creating privacy preserving visualizations. However, few of them provide sufficient feedback to users on how much utility is reduced (or preserved) during such a process. To address this, we design a visual interface along with a data manipulation pipeline that allows users to gauge utility loss while interactively and iteratively handling privacy issues in their data. Widely known and discussed types of privacy models, i.e., syntactic anonymity and differential privacy, are integrated and compared under different use case scenarios. Case study results on a variety of examples demonstrate the effectiveness of our approach.
Autors: Xumeng Wang;Jia-Kai Chou;Wei Chen;Huihua Guan;Wenlong Chen;Tianyi Lao;Kwan-Liu Ma;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 351 - 360
Publisher: IEEE
 
» A Virtual Reality Visualization Tool for Neuron Tracing
Abstract:
Tracing neurons in large-scale microscopy data is crucial to establishing a wiring diagram of the brain, which is needed to understand how neural circuits in the brain process information and generate behavior. Automatic techniques often fail for large and complex datasets, and connectomics researchers may spend weeks or months manually tracing neurons using 2D image stacks. We present a design study of a new virtual reality (VR) system, developed in collaboration with trained neuroanatomists, to trace neurons in microscope scans of the visual cortex of primates. We hypothesize that using consumer-grade VR technology to interact with neurons directly in 3D will help neuroscientists better resolve complex cases and enable them to trace neurons faster and with less physical and mental strain. We discuss both the design process and technical challenges in developing an interactive system to navigate and manipulate terabyte-sized image volumes in VR. Using a number of different datasets, we demonstrate that, compared to widely used commercial software, consumer-grade VR presents a promising alternative for scientists.
Autors: Will Usher;Pavol Klacansky;Frederick Federer;Peer-Timo Bremer;Aaron Knoll;Jeff Yarch;Alessandra Angelucci;Valerio Pascucci;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 994 - 1003
Publisher: IEEE
 
» A Wavelet Decomposition and Polynomial Fitting-Based Method for the Estimation of Time-Varying Residual Motion Error in Airborne Interferometric SAR
Abstract:
Compensating the residual motion error (RME) is very important in airborne interferometric synthetic aperture radar (InSAR). In this paper, the wavelet decomposition and polynomial fitting-based (WDPF) method is proposed for detecting and correcting the RME. Wavelet decomposition with root-mean-square error (RMSE) change ratio-based decomposition scale identification is used to detect the RME from the differential interferogram. Polynomial fitting in combination with robust estimation-based least squares is used to absorb the incidence-angle-dependent and topography-dependent components of the RME. A simulated experiment was conducted to test the proposed WDPF method. High-precision RME (with an RMSE of 0.0375 rad) was obtained, which can meet the requirements of InSAR. Real-data L- and P-band InSAR experiments were also performed to test the WDPF method. The results confirmed that the WDPF method can effectively correct the RME for the interferogram. The RMSE of the estimated digital elevation model (DEM) was reduced from 8.03 to 3.46 m and 8.18 to 3.10 m for the L- and P-band interferograms, respectively. Finally, the effects of the external DEM error and polarization on the RME calibration were investigated. The results indicated that the global InSAR DEM products can fulfill the requirement of differential interferogram generation for the WDPF method, and the multipolarization interferograms can help to reduce the effect of the topographic error phase on RME estimation.
Autors: Hai Qiang Fu;Jian Jun Zhu;Chang Cheng Wang;Hui Qiang Wang;Rong Zhao;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jan 2018, volume: 56, issue:1, pages: 49 - 59
Publisher: IEEE
 
» A Wearable Amperometric Biosensor on a Cotton Fabric for Lactate
Abstract:
The development of new bioelectronic sensors could enable significant advances in clinical analysis, environmental monitoring, and defense. Cotton fabric is a wearable material, which can contact the skin closely. Here, we demonstrate for the first time the development of a wearable amperometric biosensor on a cotton fabric for the detection of lactate. The sensor is constructed by printing carbon graphite ink and Ag/AgCl ink on a cotton fabric as the working, reference, and counter electrode. Via the immobilization of lactate oxidase, the sensor shows a sensitive detection of lactate with a detection range of 0.05–1.5 mM and a rapid measuring time of around 5 min. We anticipate that these results could open exciting opportunities for fundamental studies and practical applications of wearable bioelectronics in areas ranging from healthcare to defense.
Autors: Xiaojin Luo;Hongrui Yu;Yue Cui;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2018, volume: 39, issue:1, pages: 123 - 126
Publisher: IEEE
 
» A Wearable Device to Support the Pull Test for Postural Instability Assessment in Parkinson’s Disease
Abstract:
The pull test (PT) is a common practice to assess the postural instability of patients with Parkinson’s disease. Postural instability is a serious issue for elderly and people with neurological disease, which can cause falls. The implementation of the PT consists in observing the user response after providing a tug to the patients’ shoulders, in order to displace the center of gravity from its neutral position. The validity of the test can be compromised by a nonstandard backward tug provided to the patient. The solution proposed in this paper consists of a low-cost multisensor system allowing an instrumented estimation of the input solicitation. Moreover, the system provides supplementary information on the user postural stability, by means of a set of features extracted from the user stabilogram. A wide set of experiments have been performed to assess the system capability to provide a rough classification between stable and unstable behaviors. Results obtained demonstrate the validity of the approach proposed, with very low rates of false positive and false negative.
Autors: Bruno Andò;Salvatore Baglio;Vincenzo Marletta;Antonio Pistorio;Valeria Dibilio;Giovanni Mostile;Alessandra Nicoletti;Mario Zappia;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2018, volume: 67, issue:1, pages: 218 - 228
Publisher: IEEE
 
» A Wideband Dual-Polarized Omnidirectional Antenna for Base Station/WLAN
Abstract:
A wideband dual-polarized omnidirectional antenna is proposed for mobile communication base station and 2.4 GHz wireless local area network applications. An integrated design is achieved by combining an inverted-cone monopole for vertical polarization (VP) and a modified cross bow-tie dipole for horizontal polarization (HP). The proposed antenna has a compact size because the HP element acts as the HP radiating element and the ground plane for the VP element simultaneously. The proposed VP and HP antennas are excited by a Sub-Miniature-A connector and a broadband feeding network, respectively. The overall volume of the proposed antenna is only (with being the wavelength of the lowest frequency). Simulation results show that the dual-polarized omnidirectional antenna achieves a bandwidth (for dB) of about 41.5% (1.64–2.5 GHz) with an isolation of at least 25 dB and the gain variations at the center frequency in the horizontal plane are 0.7 dB for VP and 2.3 dB for HP. The good agreements between the simulation and measured results validate the proposed design.
Autors: Jun Wang;Lei Zhao;Zhang-Cheng Hao;Jian-Ming Jin;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 81 - 87
Publisher: IEEE
 
» A Wideband SiGe BiCMOS Frequency Doubler With 6.5-dBm Peak Output Power for Millimeter-Wave Signal Sources
Abstract:
This paper presents a balanced frequency doubler with 6.5-dBm peak output power at 204 GHz in 130-nm SiGe BiCMOS technology (/250 GHz). To convert the single-ended input signal to a differential signal for balanced operation, an on-chip transformer-based balun is employed. Detailed design procedure and compensation techniques to lower the imbalance at the output ports, based on mixed mode S parameters are proposed and verified analytically and through electromagnetic simulations. The use of optimized harmonic reflectors at the input port results in a 2-dBm increase in output power without sacrificing the bandwidth of interest. The measured conversion loss of the frequency doubler is 9 dB with 6-dBm input power at 204-GHz output. The measured peak output power is 6.5 dBm with an on-chip power amplifier stage. The 3-dB output power bandwidth is measured to be wider than 50 GHz (170–220 GHz). The total chip area of the doubler is 0.09 mm2 and the dc power consumption is 90 mW from a 1.8-V supply, which corresponds to a 5% collector efficiency.
Autors: Kefei Wu;Sriram Muralidharan;Mona Mostafa Hella;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 187 - 200
Publisher: IEEE
 
» A Wideband Variable Gain LNA With High OIP3 for 5G Using 40-nm Bulk CMOS
Abstract:
This letter presents a CMOS wideband variable gain LNA for 28-GHz 5G integrated phased-array transceivers preserving high third-order intercept point (OIP3) at all gain settings. The prototype LNA has three stages providing digitally controlled gain optimized for higher IIP3 at lower gain. The stages are coupled together using double-tuned transformers for maximum group delay flatness. Fabricated in a 40-nm CMOS process, it achieves 18–26 dB gain at 1-dB gain step with 12–14.5 dBm OIP3 and 3.3–4.3 dB noise figure, while consuming 21.5–31.4 mW across 26–33 GHz frequency range. The root-mean-square error of the gain steps is less than 0.38 dB.
Autors: Mohamed Elkholy;Sherif Shakib;Jeremy Dunworth;Vladimir Aparin;Kamran Entesari;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2018, volume: 28, issue:1, pages: 64 - 66
Publisher: IEEE
 
» A Wideband, Low-Noise Accelerometer for Sonar Wave Detection
Abstract:
This paper presents the development of a high-performance micromachined capacitive accelerometer for detection of sonar waves. The device is intended to replace existing hydrophones in towed array sonar systems, and thus, needs to meet stringent performance requirements on noise, bandwidth, and dynamic range, among others. The in-plane, single-axis accelerometer is designed based on a mode-tuning structural platform. A frame was used instead of a solid plate for the proof-mass of the device, allowing us to push undesired vibration modes beyond the operating bandwidth of the device while enabling us to employ a portion of the area for capacitive sensing elements. The designed accelerometer was fabricated on a silicon-on-insulator wafer with 100- device layer with capacitive gaps of . The sensitivity of the accelerometer is 4 V/g with a noise spectral density of better than . The fundamental resonant frequency of the device is 4.4 kHz. The open-loop dynamic range of the accelerometer, while operating at atmospheric pressure, is better than 135 dB with a cross-axis sensitivity of less than 30 dB.
Autors: Fatemeh Edalafar;Soheil Azimi;Abdul Qader Ahsan Qureshi;Bahareh Yaghootkar;Andrew Keast;Wolfgang Friedrich;Albert M. Leung;Behraad Bahreyni;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 508 - 516
Publisher: IEEE
 
» ActiVis: Visual Exploration of Industry-Scale Deep Neural Network Models
Abstract:
While deep learning models have achieved state-of-the-art accuracies for many prediction tasks, understanding these models remains a challenge. Despite the recent interest in developing visual tools to help users interpret deep learning models, the complexity and wide variety of models deployed in industry, and the large-scale datasets that they used, pose unique design challenges that are inadequately addressed by existing work. Through participatory design sessions with over 15 researchers and engineers at Facebook, we have developed, deployed, and iteratively improved ActiVis, an interactive visualization system for interpreting large-scale deep learning models and results. By tightly integrating multiple coordinated views, such as a computation graph overview of the model architecture, and a neuron activation view for pattern discovery and comparison, users can explore complex deep neural network models at both the instance-and subset-level. ActiVis has been deployed on Facebook's machine learning platform. We present case studies with Facebook researchers and engineers, and usage scenarios of how ActiVis may work with different models.
Autors: Minsuk Kahng;Pierre Y. Andrews;Aditya Kalro;Duen Horng (Polo) Chau;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 88 - 97
Publisher: IEEE
 
» Abstractocyte: A Visual Tool for Exploring Nanoscale Astroglial Cells
Abstract:
This paper presents Abstractocyte, a system for the visual analysis of astrocytes and their relation to neurons, in nanoscale volumes of brain tissue. Astrocytes are glial cells, i.e., non-neuronal cells that support neurons and the nervous system. The study of astrocytes has immense potential for understanding brain function. However, their complex and widely-branching structure requires high-resolution electron microscopy imaging and makes visualization and analysis challenging. Furthermore, the structure and function of astrocytes is very different from neurons, and therefore requires the development of new visualization and analysis tools. With Abstractocyte, biologists can explore the morphology of astrocytes using various visual abstraction levels, while simultaneously analyzing neighboring neurons and their connectivity. We define a novel, conceptual 2D abstraction space for jointly visualizing astrocytes and neurons. Neuroscientists can choose a specific joint visualization as a point in this space. Interactively moving this point allows them to smoothly transition between different abstraction levels in an intuitive manner. In contrast to simply switching between different visualizations, this preserves the visual context and correlations throughout the transition. Users can smoothly navigate from concrete, highly-detailed 3D views to simplified and abstracted 2D views. In addition to investigating astrocytes, neurons, and their relationships, we enable the interactive analysis of the distribution of glycogen, which is of high importance to neuroscientists. We describe the design of Abstractocyte, and present three case studies in which neuroscientists have successfully used our system to assess astrocytic coverage of synapses, glycogen distribution in relation to synapses, and astrocytic-mitochondria coverage.
Autors: Haneen Mohammed;Ali K. Al-Awami;Johanna Beyer;Corrado Cali;Pierre Magistretti;Hanspeter Pfister;Markus Hadwiger;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 853 - 861
Publisher: IEEE
 
» Accelerating Persistent Scatterer Pixel Selection for InSAR Processing
Abstract:
Interferometric Synthetic Aperture Radar (InSAR) is a remote sensing technology used for estimating the displacement of an object on the ground or the earth's surface itself. Persistent Scatterer-InSAR (PS-InSAR) is a category of time series algorithms enabling high resolution monitoring. PS-InSAR relies on successful selection of points that appear stable across a set of satellite images taken over time. This paper presents PtSel, a new algorithm for selecting these points, a problem known as Persistent Scatterer Selection. The key advantage of PtSel over the key existing techniques is that it does not require model assumptions, yet preserves solution accuracy. Motivated by the abundance of parallelism the algorithm exposes, we have implemented it for GPUs. Our evaluation using real-world data shows that the GPU implementation not only offers superior performance but also scales linearly with GPU count and workload size. We compare the GPU implementation and a parallel CPU implementation: a consumer grade GPU offers 18x speedup over a 16-core Ivy Bridge Xeon System, while four GPUs offer 65x speedup. The GPU solution consumes 28x less energy than the CPU-only solution. Additionally, we present a comparison with the most widely used PS-interferometry software package StaMPS, in terms of point selection coverage and precision.
Autors: Tahsin Reza;Aaron Zimmer;José Manuel Delgado Blasco;Parwant Ghuman;Tanuj Kr Aasawat;Matei Ripeanu;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jan 2018, volume: 29, issue:1, pages: 16 - 30
Publisher: IEEE
 
» Accuracy Directly Controlled Fast Direct Solution of General ${mathcal{ H}}^{2}$ -Matrices and Its Application to Solving Electrodynamic Volume Integral Equations
Abstract:
The dense matrix resulting from an integral equation (IE)-based solution of Maxwell’s equations can be compactly represented by an -matrix. Given a general dense -matrix, prevailing fast direct solutions involve approximations whose accuracy can only be indirectly controlled. In this paper, we propose new direct solution algorithms whose accuracy is directly controlled, including both factorization and inversion, for solving general -matrices. Different from the recursive inverse performed in existing -based direct solutions, this new direct solution is a one-way traversal of the cluster tree from the leaf level all the way up to the root level. The underlying multiplications and additions are carried out as they are without using formatted multiplications and additions whose accuracy cannot be directly controlled. The cluster bases and their rank of the original matrix are also updated level by level based on prescribed accuracy, without increasing computational complexity, to take into account the contributions of fill-ins generated during the direct solution procedure. For constant-rank -matrices, the proposed direct solution has a strict complexity in both time and memory. For rank that linearly grows with the electrical size, the complexity of the proposed direct solution is in factorization and inversion time, and <- nline-formula> $O(N)$ in solution time and memory for solving volume IEs (VIEs). Rapid direct solutions of electrodynamic VIEs involving millions of unknowns have been obtained on a single CPU core with directly controlled accuracy. Comparisons with state-of-the-art -based direct VIE solvers have also demonstrated the advantages of the proposed direct solution in accuracy control, as well as achieving better accuracy with much less CPU time.
Autors: Miaomiao Ma;Dan Jiao;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 35 - 48
Publisher: IEEE
 
» Accuracy Enhancement for Noninvasive Glucose Estimation Using Dual-Wavelength Photoacoustic Measurements and Kernel-Based Calibration
Abstract:
Frequent monitoring of blood glucose levels is an essential part of diabetes care, but the invasiveness of current devices deters regular measurement. Noninvasive measurement techniques are painless to implement and rely on changes in sample properties to estimate glucose concentration. However, such methods are affected by the presence of different biomolecules, resulting in an increased estimation error and necessitating calibration to obtain accurate glucose concentration estimates. The use of photoacoustic spectroscopy for continuous noninvasive glucose monitoring is studied through measurements on different sample media. In vitro photoacoustic measurements taken from aqueous glucose solutions, solutions of glucose and hemoglobin, and whole blood samples at multiple excitation wavelengths show amplitude and area-based signal features to rise with the increase in sample glucose concentration. The calibration of photoacoustic measurements from glucose solutions using Gaussian kernel-based regression results in a root mean square error (RMSE), mean absolute difference (MAD), and mean absolute relative difference (MARD) of 7.64 mg/dl, 5.23 mg/dl, and 2.07%, respectively. Kernel-based calibration also performs well on solutions of glucose and hemoglobin, and whole blood samples, resulting in lower estimation errors than that of previous efforts and with glucose estimates being in the acceptable zones of a Clarke error grid (CEG). It allows for individual calibration of photoacoustic measurements in vivo, resulting in an RMSE, MAD, and MARD of 19.46 mg/dl, 10.79 mg/dl, and 7.01%, respectively, with 89.80% of the estimates being within Zone A of the CEG. The improvement in estimation accuracy with dual-wavelength photoacoustic measurements and kernel-based calibration would enable continuous noninvasive glucose monitoring, facilitating improved diabetic care.
Autors: Praful P. Pai;Arijit De;Swapna Banerjee;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2018, volume: 67, issue:1, pages: 126 - 136
Publisher: IEEE
 
» Achieving Full-Duplex Communication: Magnetless Parametric Circulators for Full-Duplex Communication Systems
Abstract:
In a crowded electromagnetic spectrum with ever-increasing demand for higher data rates to enable multimedia-rich applications and services, the efficient use of wireless resources becomes crucial. For this reason, full-duplex communication [1]-[4], which increases the capacity of transmission channels by operating the uplink and downlink simultaneously on the same frequency channel (see Figure 1), is returning to the spotlight after decades of being presumed impractical. This long-held assumption resulted mainly from the need for large isolation (IX) between the transmit (Tx) and receive (Rx) nodes [also known as self-interference cancellation (SIC)], which typically needs to be greater than 100 dB, a challenging task that requires several innovations at the network and physical layer levels.
Autors: Ahmed Kord;Dimitrios L. Sounas;Andrea Alù;
Appeared in: IEEE Microwave Magazine
Publication date: Jan 2018, volume: 19, issue:1, pages: 84 - 90
Publisher: IEEE
 
» Acoustic Radiation Force-Induced Creep–Recovery (ARFICR): A Noninvasive Method to Characterize Tissue Viscoelasticity
Abstract:
Ultrasound shear wave elastography is a promising noninvasive, low cost, and clinically viable tool for liver fibrosis staging. Current shear wave imaging technologies on clinical ultrasound scanners ignore shear wave dispersion and use a single group velocity measured over the shear wave bandwidth to estimate tissue elasticity. The center frequency and bandwidth of shear waves induced by acoustic radiation force depend on the ultrasound push beam (push duration, -number, etc.) and the viscoelasticity of the medium, and therefore are different across scanners from different vendors. As a result, scanners from different vendors may give different tissue elasticity measurements within the same patient. Various methods have been proposed to evaluate shear wave dispersion to better estimate tissue viscoelasticity. A rheological model such as the Kelvin–Voigt model is typically fitted to the shear wave dispersion to solve for the elasticity and viscosity of tissue. However, these rheological models impose strong assumptions about frequency dependence of elasticity and viscosity. Here, we propose a new method called Acoustic Radiation Force Induced Creep-Recovery (ARFICR) capable of quantifying rheological model-independent measurements of elasticity and viscosity for more robust tissue health assessment. In ARFICR, the creep-recovery time signal at the focus of the push beam is used to calculate the relative elasticity and viscosity (scaled by an unknown constant) over a wide frequency range. Shear waves generated during the ARFICR measurement are also detected and used to calculate the shear wave velocity at its center frequency, which is then used to calibrate the relative elasticity and viscosity to absolute elasticity and viscosity. In this paper, finite-element method simulations and experiments in tissue mimicking phantoms are used to validate and characterize the exte- t of viscoelastic quantification of ARFICR. The results suggest that ARFICR can measure tissue viscoelasticity reliably. Moreover, the results showed the strong frequency dependence of viscoelastic parameters in tissue mimicking phantoms and healthy liver.
Autors: Carolina Amador Carrascal;Shigao Chen;Matthew W. Urban;James F. Greenleaf;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Jan 2018, volume: 65, issue:1, pages: 3 - 13
Publisher: IEEE
 
» Actionable Analytics for Software Engineering
Abstract:
Although intensive research on software analytics has been going on for nearly a decade, a repeated complaint in software analytics is that industrial practitioners find it hard to apply the results generated from data science. This theme issue aims to reflect on actionable analytics for software engineering and to document a catalog of success stories in which analytics has been proven actionable and useful, in some significant way, in an organization. This issue features five articles covering promising analytical methods for improving change triage, strategic maintenance, and team robustness, as well as the success stories of applying analytical tools during an organizational transformation.
Autors: Ye Yang;Davide Falessi;Tim Menzies;Jairus Hihn;
Appeared in: IEEE Software
Publication date: Jan 2018, volume: 35, issue:1, pages: 51 - 53
Publisher: IEEE
 
» Actionable Analytics for Strategic Maintenance of Critical Software: An Industry Experience Report
Abstract:
NASA has been successfully sustaining the continuous operation of its critical navigation software systems for over 12 years. To accomplish this, NASA scientists must continuously monitor their process, report on current system quality, forecast maintenance effort, and sustain required staffing levels. This report presents some examples of the use of a robust software metrics and analytics program that enables actionable strategic maintenance management of a critical system (Monte) in a timely, economical, and risk-controlled fashion. This article is part of a special issue on Actionable Analytics for Software Engineering.
Autors: Dan Port;Bill Taber;
Appeared in: IEEE Software
Publication date: Jan 2018, volume: 35, issue:1, pages: 58 - 63
Publisher: IEEE
 
» Active Learning-Based Optimized Training Library Generation for Object-Oriented Image Classification
Abstract:
In this paper, we introduce an active learning (AL)-based object training library generation for a multiclassifier object-oriented image analysis (OOIA) system. While several AL approaches do exist for pixel-based training library generation and for hyperspectral image classification, there is no standard training library generation strategy for OOIA of very high spatial resolution images. Given a sufficient number of training samples, supervised classification is the method of choice for image classification. However, this strategy becomes computationally expensive with the increase in the number of classes or the number of images to be classified. The above-mentioned issue is solved in this proposed method, where an optimized training library of objects (superpixels) is generated based on a batch mode AL approach. A softmax classifier is used as a detector in this method, which helps in determining the right samples to be chosen for library updation. To this end, we construct a multiclassifier system with max-voting decision to classify an image at pixel level. This algorithm was applied on three different very high-resolution airborne data sets, each with varying complexity in terms of variations in geographical context, sensors, illumination, and view angles. Our method has empirically outperformed the traditional OOIA by producing equivalent accuracy with a training library that is orders of magnitude smaller. In addition, the most distinctive ability of the algorithm is experienced in the most heterogeneous data set, where its performance in terms of accuracy is around twice the performance of the traditional method in the same situation. The generality of this classification strategy is proved through its performance on multispectral images and for cross-domain application. Finally, the robustness of this method is identified by comparing its performance with an alternative AL approach—self-learning-based semisupervised SVM. The capability- of the proposed method to handle highly heterogeneous data is identified as the primary reason for its robustness.
Autors: Rajeswari Balasubramaniam;Srivalsan Namboodiri;Rama Rao Nidamanuri;Rama Krishna Sai Subrahmanyam Gorthi;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jan 2018, volume: 56, issue:1, pages: 575 - 585
Publisher: IEEE
 
» Active Reading of Visualizations
Abstract:
We investigate whether the notion of active reading for text might be usefully applied to visualizations. Through a qualitative study we explored whether people apply observable active reading techniques when reading paper-based node-link visualizations. Participants used a range of physical actions while reading, and from these we synthesized an initial set of active reading techniques for visualizations. To learn more about the potential impact such techniques may have on visualization reading, we implemented support for one type of physical action from our observations (making freeform marks) in an interactive node-link visualization. Results from our quantitative study of this implementation show that interactive support for active reading techniques can improve the accuracy of performing low-level visualization tasks. Together, our studies suggest that the active reading space is ripe for research exploration within visualization and can lead to new interactions that make for a more flexible and effective visualization reading experience.
Autors: Jagoda Walny;Samuel Huron;Charles Perin;Tiffany Wun;Richard Pusch;Sheelagh Carpendale;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 770 - 780
Publisher: IEEE
 
» Active Self-Paced Learning for Cost-Effective and Progressive Face Identification
Abstract:
This paper aims to develop a novel cost-effective framework for face identification, which progressively maintains a batch of classifiers with the increasing face images of different individuals. By naturally combining two recently rising techniques: active learning (AL) and self-paced learning (SPL), our framework is capable of automatically annotating new instances and incorporating them into training under weak expert recertification. We first initialize the classifier using a few annotated samples for each individual, and extract image features using the convolutional neural nets. Then, a number of candidates are selected from the unannotated samples for classifier updating, in which we apply the current classifiers ranking the samples by the prediction confidence. In particular, our approach utilizes the high-confidence and low-confidence samples in the self-paced and the active user-query way, respectively. The neural nets are later fine-tuned based on the updated classifiers. Such heuristic implementation is formulated as solving a concise active SPL optimization problem, which also advances the SPL development by supplementing a rational dynamic curriculum constraint. The new model finely accords with the “instructor-student-collaborative” learning mode in human education. The advantages of this proposed framework are two-folds: i) The required number of annotated samples is significantly decreased while the comparable performance is guaranteed. A dramatic reduction of user effort is also achieved over other state-of-the-art active learning techniques. ii) The mixture of SPL and AL effectively improves not only the classifier accuracy compared to existing AL/SPL methods but also the robustness against noisy data. We evaluate our framework on two challenging datasets, which include hundreds of persons under diverse conditions, and demonstrate very promising results. Please find the code of this project at: http://h- p.sysu.edu.cn/projects/aspl/.
Autors: Liang Lin;Keze Wang;Deyu Meng;Wangmeng Zuo;Lei Zhang;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2018, volume: 40, issue:1, pages: 7 - 19
Publisher: IEEE
 
» Activity-Centered Domain Characterization for Problem-Driven Scientific Visualization
Abstract:
Although visualization design models exist in the literature in the form of higher-level methodological frameworks, these models do not present a clear methodological prescription for the domain characterization step. This work presents a framework and end-to-end model for requirements engineering in problem-driven visualization application design. The framework and model are based on the activity-centered design paradigm, which is an enhancement of human-centered design. The proposed activity-centered approach focuses on user tasks and activities, and allows an explicit link between the requirements engineering process with the abstraction stage—and its evaluation—of existing, higher-level visualization design models. In a departure from existing visualization design models, the resulting model: assigns value to a visualization based on user activities; ranks user tasks before the user data; partitions requirements in activity-related capabilities and nonfunctional characteristics and constraints; and explicitly incorporates the user workflows into the requirements process. A further merit of this model is its explicit integration of functional specifications, a concept this work adapts from the software engineering literature, into the visualization design nested model. A quantitative evaluation using two sets of interdisciplinary projects supports the merits of the activity-centered model. The result is a practical roadmap to the domain characterization step of visualization design for problem-driven data visualization. Following this domain characterization model can help remove a number of pitfalls that have been identified multiple times in the visualization design literature.
Autors: G. Elisabeta Marai;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 913 - 922
Publisher: IEEE
 
» Ad Astra Diplomacy [Spectral lines]
Abstract:
In the 2015 science fiction blockbuster The Martian, the United States makes a rushed effort to send life-sustaining provisions to its marooned astronaut on the Red Planet. Alas, the attempt fails when NASA's resupply rocket explodes shortly after liftoff. But officials with China’s national space program save the day when they offer the services of a previously secret Chinese rocket that is capable of ferrying the needed materials. The Martian movie and the book on which it is based have been hailed for their many realistic technical details.
Autors: David Schneider;
Appeared in: IEEE Spectrum
Publication date: Jan 2018, volume: 55, issue:1, pages: 6 - 6
Publisher: IEEE
 
» Ad Hoc and Sensor Networks
Abstract:
The articles in this special section focus on ad hoc and wireless sensor networks. The introduction of mobile and sensor-equipped devices has been a revolution for human life, and already we are surrounded by computing, sensing and communication activities. Similar to the problem of how to efficiently communicate among humans, with the introduction of mobile and sensing devices, it became essential to design efficient algorithms to efficiently compute, sense and communicate and to cope with novel issues, such as security and privacy, raised by those new paradigms. In particular, problems such as resource allocations and efficient routing attracted a lot of attention.
Autors: Edoardo Biagioni;Silvia Giordano;Ciprian Dobre;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2018, volume: 56, issue:1, pages: 118 - 118
Publisher: IEEE
 
» Adaptive Analog Function Computation via Fading Multiple-Access Channels
Abstract:
In this letter, we propose an adaptive analog function computation (AFC) via fading multiple-access channels in which multiple sensors simultaneously send their observations and then the fusion center computes the desired function via the superposition property of wireless channels. In particular, each sensor adaptively sends its observation to the fusion center based on its causal channel state information (CSI). Numerical results show that the adaptive AFC significantly outperforms the conventional non-adaptive AFC in terms of the outage probability of function estimation error. The adaptive AFC operates in a fully distributed manner with local and causal CSI, applicable to various practical sensor network applications.
Autors: Sang-Woon Jeon;Bang Chul Jung;
Appeared in: IEEE Communications Letters
Publication date: Jan 2018, volume: 22, issue:1, pages: 213 - 216
Publisher: IEEE
 
» Adaptive Communication Protocols in Flying Ad Hoc Network
Abstract:
The flying ad hoc network (FANET) is a new paradigm of wireless communication that governs the autonomous movement of UAVs and supports UAV-to-UAV communication. A FANET can provide an effective real-time communication solution for the multiple UAV systems considering each flying UAV as a router. However, existing mobile ad hoc protocols cannot meet the needs of FANETs due to high-speed mobility and frequent topology change. In addition, the complicated flight environment and varied flight tasks lead to the traditional built-in-rules protocols no longer meeting the demands of autonomy. Hence, we have proposed adaptive hybrid communication protocols including a novel position-prediction-based directional MAC protocol (PPMAC) and a self-learning routing protocol based on reinforcement learning (RLSRP). The performance results show that the proposed PPMAC overcomes the directional deafness problem with directional antennas, and RLSRP provides an automatically evolving and more effective routing scheme. Our proposed hybrid adaptive communication protocols have the potential to provide an intelligent and highly autonomous communication solution for FANETs, and indicate the main research orientation of FANET protocols.
Autors: Zhigao Zheng;Arun Kumar Sangaiah;Tao Wang;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2018, volume: 56, issue:1, pages: 136 - 142
Publisher: IEEE
 
» Adaptive Compressed Sensing Using Intra-Scale Variable Density Sampling
Abstract:
Adaptive sensing has the potential to achieve near optimal performance by using current measurements to design subsequential sensing vectors. Existing adaptive sensing methods are usually based on recursive bisection or known structures of certain sparse representations. They suffer from either wasting extra measurements for detecting large coefficients, or missing these coefficients because of violations of these structures. In this paper, intra-scale variable density sampling (InVDS) is presented to capture the heterogeneous property of coefficients. First, Latin hypercube sampling with good uniformity is employed to find areas containing large coefficients. Then, the neighborhoods of largest coefficients are measured according to the block-sparsity or clustering property. Finally, the denoising-based approximate message passing algorithm is introduced to enhance the performance of image reconstruction. The probability that our sampling method fails to obtain large coefficients is analyzed. The superiority of InVDS is validated by numerical experiments with wavelet, discrete cosine, and Hadamard transforms.
Autors: Jiying Liu;Cong Ling;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 547 - 558
Publisher: IEEE
 
» Adaptive Critic-Based Event-Triggered Control for HVAC System
Abstract:
The heating, ventilation, and air conditioning system is an important component for achieving desired thermal condition in rooms or spaces in buildings, office complex, or airports. This paper proposes a real-time event-triggered adaptive critic controller for generating near optimal control actions to achieve desired temperatures. The desired temperatures may have variable or fixed values over time. The real-time controller is designed in two phases. Initially event-triggered control actions are generated by linear quadratic regulator for small period while the actor-critic network of controller is trained. Later, adaptive critic controller takes over for event-based actions. Hence, the event triggering conditions for both general linear and nonlinear discrete time systems using Lyapunov stability analysis are derived in this paper. The event-based actor-critic network weight update formulation and ultimate boundedness of parameters are also presented in this paper. The proposed approach has been validated for different and common temperature sets for four zones, where the control execution events are minimized to 20 and 26, respectively.
Autors: Narendra Kumar Dhar;Nishchal Kumar Verma;Laxmidhar Behera;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 178 - 188
Publisher: IEEE
 
» Adaptive Estimation of Quantiles in a Simulation Model
Abstract:
Let be an valued random variable, let be a measurable function and set . Given a sample of of size , we consider the problem of estimating the quantile of of a given level . A method for choosing the parameter of a surrogate model of is introduced, and it is shown that the corresponding surrogate quantile estimate achieves the rate of convergence bounded by the sum of the minimal rate of convergence of the quantile estimates corresponding to the given surrogate estimates and a term of order . The finite sample size behavior of this quantile estimate is illustrated by applying it to simulated data and to a quantile estimation problem in mechanical engineering.
Autors: Michael Kohler;Adam Krzyżak;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2018, volume: 64, issue:1, pages: 501 - 512
Publisher: IEEE
 
» Adaptive Fuzzy Logic Control of Fuel-Cell-Battery Hybrid Systems for Electric Vehicles
Abstract:
In this paper, we propose an adaptive control approach with fuzzy logic parameter tuning (AFLPT) for the energy management of electric vehicles that are using fuel cell battery hybrid systems. The controller is adaptive to different driving conditions including normal, regenerative, and overload conditions. Specifically, the power flow between the fuel cell (FC) and the Li-ion battery is controlled in real time to maintain the battery state of charge (SOC) at a desirable level while satisfying the FC dynamic constraints. For guaranteeing performance in different driving conditions, the FLPT is integrated with the adaptive controller. Moreover, theoretical properties of the designed controller are analyzed. Simulation and experiment results illustrate the effectiveness of the proposed strategy for FC-battery hybrid systems in electric vehicles.
Autors: Jian Chen;Chenfeng Xu;Chengshuai Wu;Weihua Xu;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 292 - 300
Publisher: IEEE
 
» Adaptive Nonlinear Disturbance Observer Using a Double-Loop Self-Organizing Recurrent Wavelet Neural Network for a Two-Axis Motion Control System
Abstract:
This paper proposes an adaptive nonlinear disturbance observer (ANDO) for identification and control of a two-axis motion control system driven by two permanent-magnet linear synchronous motors servo drives. The proposed control scheme incorporates a feedback linearization controller (FLC), a new double-loop self-organizing recurrent wavelet neural network (DLSORWNN) controller, a robust controller, and an controller. First, an FLC is designed to stabilize the XY table system. Then, a nonlinear disturbance observer (NDO) is designed to estimate the nonlinear lumped parameter uncertainties that include the external disturbances, cross-coupled interference, and frictional force. However, the XY table performance is degraded by the NDO error due to parameter uncertainties. To improve the robustness, the ANDO is designed to attain this purpose. In addition, the robust controller is designed to recover the approximation error of the DLSORWNN, while the controller is specified such that the quadratic cost function is minimized and the worst-case effect of the NDO error must be attenuated below a desired attenuation level. The online adaptive control laws are derived using the Lyapunov stability analysis and control theory, so that the stability of the ANDO can be guaranteed. The experimental results show the improvements in disturbance suppression and parameter uncertainties, which illustrate the superiority of the ANDO control scheme.
Autors: Fayez F. M. El-Sousy;Khaled Ali Abuhasel;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 764 - 786
Publisher: IEEE
 
» Adaptive Online Monitoring of Voltage Stability Margin via Local Regression
Abstract:
An online voltage stability margin (VSM) monitoring approach based on local regression and adaptive database is proposed. Considering the increasing variability and uncertainty of power system operation, this approach utilizes the locality of underlying pattern between VSM and reactive power reserve (RPR), and can adapt to the changing condition of system. LASSO is tailored to solve the local regression problem so as to mitigate the curse of dimensionality for large scale system. Along with the VSM prediction, its confidence interval is also estimated simultaneously in a simple but effective way, and utilized as an evidence to trigger the database updating. IEEE 30-bus system and a 60,000-bus large system are used to test and demonstrate the proposed approach. The results show that the proposed approach can be successfully employed in online voltage stability monitoring for real size systems, and the adaptivity of model and data endows the proposed approach with the advantage in the circumstances where large and unforeseen changes of system condition are inevitable.
Autors: Shiyang Li;Venkataramana Ajjarapu;Miodrag Djukanovic;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 701 - 713
Publisher: IEEE
 
» Adaptive Policy for Load Frequency Control
Abstract:
Till date, various load frequency control (LFC) schemes have been reported and every scheme has its own way of disturbance rejection capability. Utilizing some of them together may bring improved performance. Keeping this fact in mind, an adaptive control policy is proposed in this letter. The policy incorporates the concept of enhancing and lowering the controller activity by assigning them weights at every instance throughout the operation. Thus, there is no need to go for a new LFC scheme until required, and a guaranteed improved performance would be achieved. Different case studies including single and multi-area power systems have been conducted to verify the accuracy and efficiency of the proposed method.
Autors: Sandeep Hanwate;Yogesh V. Hote;Sahaj Saxena;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 1142 - 1144
Publisher: IEEE
 
» Adaptive Relay Selection and Power Allocation for OFDM Cooperative Underwater Acoustic Systems
Abstract:
The increasing use of relays in underwater acoustic (UWA) communications is a driving force to explore efficient techniques that can significantly improve the system performance. To fully exploit the benefits of cooperative systems, efficient management of resources including relays and power is required. In this paper, both optimal relay selection and power loading issues are investigated for an orthogonal frequency division multiplexing (OFDM) cooperative transmission over UWA channel. In our analysis, we consider amplify-and-forward (AF) relaying with perfect channel state information (CSI) at the source, relay, and destination nodes. Moreover, we assume sparse and frequency-selective Rician fading in the presence of colored Gaussian ambient noise. Unlike previous works on this topic, in our study, the power of noise is not identical for all subcarriers at both the relay and destination nodes. We solve two optimization problems that rely on the minimization of the bit error rate (BER) and maximization of the system capacity. In each problem, both optimal relay selection and power loading issues are addressed in two dependent phases. In the first phase, an unconstrained optimization problem is solved to determine the optimal relay out of multiple relays vertically located at different depths of water. We adopt all-subcarrier (AS) basis approach in our OFDM-based transmission model in which a single relay is engaged to transmit the entire OFDM block to the destination. In the second phase, after selecting the optimal relay, another optimization problem is solved to obtain the optimal power allocation. This is jointly done at both the source and relay nodes under total power constraint and fixed subcarrier rate. Extensive simulations are conducted to evaluate the performance of proposed algorithms under different scenarios.
Autors: Abdollah Doosti-Aref;Ataollah Ebrahimzadeh;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2018, volume: 17, issue:1, pages: 1 - 15
Publisher: IEEE
 
» Adaptive Resource Allocation and Provisioning in Multi-Service Cloud Environments
Abstract:
In the current cloud business environment, the cloud provider (CP) can provide a means for offering the required quality of service (QoS) for multiple classes of clients. We consider the cloud market where various resources such as CPUs, memory, and storage in the form of Virtual Machine (VM) instances can be provisioned and then leased to clients with QoS guarantees. Unlike existing works, we propose a novel Service Level Agreement (SLA) framework for cloud computing, in which a price control parameter is used to meet QoS demands for all classes in the market. The framework uses reinforcement learning (RL) to derive a VM hiring policy that can adapt to changes in the system to guarantee the QoS for all client classes. These changes include: service cost, system capacity, and the demand for service. In exhibiting solutions, when the CP leases more VMs to a class of clients, the QoS is degraded for other classes due to an inadequate number of VMs. However, our approach integrates computing resources adaptation with service admission control based on the RL model. To the best of our knowledge, this study is the first attempt that facilitates this integration to enhance the CP's profit and avoid SLA violation. Numerical analysis stresses the ability of our approach to avoid SLA violation while maximizing the CP's profit under varying cloud environment conditions.
Autors: Ayoub Alsarhan;Awni Itradat;Ahmed Y. Al-Dubai;Albert Y. Zomaya;Geyong Min;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jan 2018, volume: 29, issue:1, pages: 31 - 42
Publisher: IEEE
 
» ADP-MAC: An Adaptive and Dynamic Polling-Based MAC Protocol for Wireless Sensor Networks
Abstract:
Channel polling activity in MAC protocols of wireless sensor network (WSN) significantly governs energy, delay, and lifetime of the network, and therefore, it is required to adjust the polling intervals in accordance with the incoming traffic patterns. In this paper, an asynchronous duty-cycle-based MAC protocol: adaptive and dynamic polling-MAC (ADP-MAC) has been developed. This paper took a novel approach of switching the polling interval distribution of the receiver nodes by monitoring the co-efficient of variation of the incoming traffic. To represent different applications of WSN, constant-bit rate, Poisson, and Bursty arrivals have been used, whereas three types of polling distributions: deterministic, exponential, and dynamic have been studied. The performance parameters, such as energy, delay, and packet loss, are used to evaluate ADP-MAC against an established protocol synchronized channel polling-MAC (SCP-MAC). The major finding of this paper is that when the traffic arrival and polling interval distribution of ADP-MAC are in conformance, the performance in terms of both delay and energy turns out to be the best. Furthermore, ADP-MAC has been found to outperform SCP-MAC for each type of arrivals.
Autors: Shama Siddiqui;Sayeed Ghani;Anwar Ahmed Khan;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 860 - 874
Publisher: IEEE
 
» Advanced Boundary Electrode Modeling for tES and Parallel tES/EEG
Abstract:
This paper explores advanced electrode modeling in the context of separate and parallel transcranial electrical stimulation (tES) and electroencephalography (EEG) measurements. We focus on boundary condition-based approaches that do not necessitate adding auxiliary elements, e.g., sponges, to the computational domain. In particular, we investigate the complete electrode model (CEM) which incorporates a detailed description of the skin-electrode interface including its contact surface, impedance, and normal current distribution. The CEM can be applied for both tES and EEG electrodes which are advantageous when a parallel system is used. In comparison to the CEM, we test two important reduced approaches: the gap model (GAP) and the point electrode model (PEM). We aim to find out the differences of these approaches for a realistic numerical setting based on the stimulation of the auditory cortex. The results obtained suggest, among other things, that GAP and GAP/PEM are sufficiently accurate for the practical application of tES and parallel tES/EEG, respectively. Differences between CEM and GAP were observed mainly in the skin compartment, where only CEM explains the heating effects characteristic to tES.
Autors: Sampsa Pursiainen;Britte Agsten;Sven Wagner;Carsten H. Wolters;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Jan 2018, volume: 26, issue:1, pages: 37 - 44
Publisher: IEEE
 
» Advanced Deep-Learning Techniques for Salient and Category-Specific Object Detection: A Survey
Abstract:
Object detection, including objectness detection (OD), salient object detection (SOD), and category-specific object detection (COD), is one of the most fundamental yet challenging problems in the computer vision community. Over the last several decades, great efforts have been made by researchers to tackle this problem, due to its broad range of applications for other computer vision tasks such as activity or event recognition, content-based image retrieval and scene understanding, etc. While numerous methods have been presented in recent years, a comprehensive review for the proposed high-quality object detection techniques, especially for those based on advanced deep-learning techniques, is still lacking. To this end, this article delves into the recent progress in this research field, including 1) definitions, motivations, and tasks of each subdirection; 2) modern techniques and essential research trends; 3) benchmark data sets and evaluation metrics; and 4) comparisons and analysis of the experimental results. More importantly, we will reveal the underlying relationship among OD, SOD, and COD and discuss in detail some open questions as well as point out several unsolved challenges and promising future works.
Autors: Junwei Han;Dingwen Zhang;Gong Cheng;Nian Liu;Dong Xu;
Appeared in: IEEE Signal Processing Magazine
Publication date: Jan 2018, volume: 35, issue:1, pages: 84 - 100
Publisher: IEEE
 
» Advanced Modeling Techniques [Book/Software Reviews]
Abstract:
The text covers both theoretical and practical aspects of behavioral modeling and DPD for RF PAs and wireless transmitters. It is authored by three highly respected researchers in the field. The book is organized into ten chapters. Each of the book’s chapters is complemented with software tools available through the Wiley website (www.wiley.com/go/Ghannouchi/Behavioral). The simulation software allows users to apply the theories presented in the book to solve real problems. This book will be a very valuable resource for design engineers, industrial engineers, applications engineers, postgraduate students, and researchers working on PA modeling, linearization, and design.
Autors: Anding Zhu;
Appeared in: IEEE Microwave Magazine
Publication date: Jan 2018, volume: 19, issue:1, pages: 112 - 114
Publisher: IEEE
 
» Agile Laser Beam Deflection With High Steering Precision and Angular Resolution Using Liquid Crystal Optical Phased Array
Abstract:
To improve the steering precision and angular resolution of liquid-crystal optical phased array, in this paper, we proposed a modified periodic phase controlled method to realize a continuous scanning with a constant angular resolution of less than 20 μrad, meanwhile, its precision is less than 5 μrad (rms). Also, another method we proposed is called subaperture coherence that can realize even better angular resolution less than 5 μrad, which is the limitation of our measurement instrument.
Autors: Xiangru Wang;Liang Wu;Caidong Xiong;Man Li;Qinggui Tan;Jiyang Shang;Shuanghong Wu;Qi Qiu;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jan 2018, volume: 17, issue:1, pages: 26 - 28
Publisher: IEEE
 
» Air-Quality Monitoring in an Urban Area in the Tropical Andes
Abstract:
Manizales is a tropical Andean city in Colombia that has obtained outstanding achievements in the continuous and effective monitoring of the air quality. This article describes the air-quality monitoring system of Manizales and its corresponding data center, which is a system designed to perform a periodic vigilance of the concentration of the main air contaminants. The structure of one data warehouse is explained, along with the components of monitoring networks, equipments, and technological tools and processes that allow the acquisition, storage, processing, and analysis of the air-quality data.
Autors: Liliana Romo-Melo;Beatriz Aristizabal;Mauricio Orozco-Alzate;
Appeared in: IEEE Potentials
Publication date: Jan 2018, volume: 37, issue:1, pages: 34 - 39
Publisher: IEEE
 
» Airspace Collision Risk Hot-Spot Identification using Clustering Models
Abstract:
A key safety indicator for airspace is its collision risk estimate, which is compared against a target level of safety to provide a quantitative basis for judging the safety of operations in airspace. However, this quantitative basis fails to provide any insight regarding the magnitude, location, and timing of the risk of collision, distributed within a given airspace. In this paper, we propose a methodology for the identification of collision risk hot spots in a given airspace. The proposed methodology consists of processing air traffic data and developing traffic routes based on entry and exit points within the airspace. These routes and other flight information are then used to project air-traffic crossings and cluster potential collisions. The proposed method then estimates the collision risk for each identified cluster, culminating in risk assessment for the entire airspace. The model extends and adopts the state-of-the art clustering models, systemically identifies airspace collision risk hot spots, and further analyses hot spots by analyzing cluster features (number of points and contribution to overall risk) with flight levels and time of day. Experiments were conducted using one-month traffic data (25 440 flights) from Bahrain en-route airspace. By visualizing crossing points and clustering them in a 2-D geographic information system model we are able to identify collision risk hot spots, which contribute significantly to overall collision risk.
Autors: Minh-Ha Nguyen;Sameer Alam;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2018, volume: 19, issue:1, pages: 48 - 57
Publisher: IEEE
 
» Algebraic Certificates of (Semi)Definiteness for Polynomials Over Fields Containing the Rationals
Abstract:
Sum of squares (SOS) decompositions for positive semidefinite polynomials are usually computed numerically, using convex optimization solvers. The precision of the decompositions can be improved by increasing the number of digits used in the computations, but, when the number of variables is greater than the length (i.e., the minimum number of squares needed for the decomposition) of the polynomial, it is difficult to obtain an exact SOS decomposition with the existing methods. A new algorithm, which works well in “almost all” such cases, is proposed here. The results of randomly generated experiments are reported to compare the proposed algorithm with those based on convex optimization.
Autors: Laura Menini;Corrado Possieri;Antonio Tornambè;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2018, volume: 63, issue:1, pages: 158 - 173
Publisher: IEEE
 
» Aliens From Planet Pittsburgh: How Two Young Roboticists From Carnegie Mellon Pioneered Digital Lighting
Abstract:
The show started at twilight. On a balmy evening last February outside Tasmania’s Museum of Old and New Art I sat spellbound, leaning back on a granite bench gazing up at a large white fiberglass canopy that floated several meters above my head. Light projected onto it began to gradually morph from one gorgeous hue to another. Lilac deepened to purple, then shifted to burnt orange, to chartreuse green, and on it went. Meanwhile, through a rectangular aperture cut in the middle of the canopy, the darkening sky seemed mysteriously to lose depth, becoming a flat plane of color that looked as if it had been painted on the ceiling. The interplay between artificial and natural light was hallucinatory: as the hue of the former changed, so apparently did that of the latter. In a silence punctured only by the raucous laughing of a pair of kookaburras the program shimmered on, ending after perhaps an hour, when the sky had become pitch black. A truly magical experience, one that I shall remember as long as I live (Figs. 13).
Autors: Bob Johnstone;
Appeared in: Proceedings of the IEEE
Publication date: Jan 2018, volume: 106, issue:1, pages: 201 - 208
Publisher: IEEE
 
» Aligning the Light Without Channel State Information for Visible Light Communications
Abstract:
The use of light-emitting diodes (LEDs) for ambient illumination leads to visible light communications (VLC) as a promising technology for providing both constant lighting and high-speed wireless services in indoor environments. Since multiple LED sources can be transmitted to several users, this scenario naturally forms a multiple-user multiple-input single-output system. In this sense, transmit precoding (TPC) schemes based on channel state information at the transmitter (CSIT) originally devised for radio-frequency (RF) systems have been proposed for their implementation in VLC. However, beyond providing CSIT or the need for cooperation among transmitters, which also result challenging in RF systems, there are several constraints such as the non-negativity of the transmitted signal or providing constant illumination that hamper the performance of TPC schemes in VLC. Considering these constraints, this paper explores the use of blind interference alignment (BIA) for achieving multiplexing gain without CSIT or cooperation among LED lights. To do that, we devise the concept of reconfigurable photodetector that allows switching among distinct and linearly independent channel responses. Simulation results show that the use of BIA in VLC systems schemes based on the proposed reconfigurable photodetector results suitable for VLC systems.
Autors: Máximo Morales-Céspedes;Martha Cecilia Paredes-Paredes;Ana García Armada;Luc Vandendorpe;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jan 2018, volume: 36, issue:1, pages: 91 - 105
Publisher: IEEE
 
» Allocation of Frequency Control Reserves and Its Impact on Wear and Tear on a Hydropower Fleet
Abstract:
Power systems are making a transition from purely technical, centrally planned systems to market based, decentralized systems. The need for balancing power and frequency control reserves are increasing, partially due to variable renewable production, which gives an opportunity for new incomes but also a challenge in terms of changed modes of operation with risk for reduced lifetime for controllable power plants. This paper investigates how the allocation of a sold volume of frequency control reserves within a large hydropower production fleet can affect the costs of providing primary and secondary reserves, in terms of its impact on wear and fatigue, production losses, and the quality of the delivered frequency control. The results show that for primary control, low static gain in the governors results in poor quality and a large amount of load cycles of the units. High static gain, on the other hand, increases the production losses. The control work of the fleet can be reduced by using a proper balance of primary and secondary control gain on each unit, although the intuitive results from linear models exaggerate this effect. Automatic secondary control improves the system frequency quality but also increases the wear.
Autors: Linn Saarinen;Per Norrlund;Weijia Yang;Urban Lundin;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 430 - 439
Publisher: IEEE
 
» Always-On 12-nW Acoustic Sensing and Object Recognition Microsystem for Unattended Ground Sensor Nodes
Abstract:
This paper presents an ultra-low power acoustic sensing and object recognition microsystem for Internet of Things applications. The microsystem is targeted for unattended ground sensor nodes where long-term (decades) life time is desired without the need for battery replacement. The system incorporates an microelectromechanical systems microphone as a frontend sensor along with active circuitry to identify target objects. We introduce an algorithm-circuit cross optimization to realize a 12-nW stand-alone microsystem that integrates the analog frontend with the digital backend signal classifier. The frequency-domain analysis of target audio signals reveals that the system can operate with a relatively low bandwidth (<500 Hz) and SNR (>3 dB) which significantly relaxes power constraints on both analog frontend and digital backend circuits. To further relax the current requirement of the preceding amplifier, we propose an 8-bit SAR-analog-to-digital converter that is designed to have a highly reduced sampling capacitance (<50 fF). For the digital backend, we propose a feature extractor using the serialized tones-of-interest discrete Fourier transform, replacing a conventional high-power/area-consuming parallel feature extraction using the fast Fourier transform. This approach reduces area and thus leakage power which often dominates the overall power consumption. The proposed system successfully identifies a number of target objects including an electrical generator, a small car, and a truck with >95% reliability and consumes only 12 nW with continuous monitoring.
Autors: Seokhyeon Jeong;Yu Chen;Taekwang Jang;Julius Ming-Lin Tsai;David Blaauw;Hun-Seok Kim;Dennis Sylvester;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2018, volume: 53, issue:1, pages: 261 - 274
Publisher: IEEE
 
» Amateur Drone Surveillance: Applications, Architectures, Enabling Technologies, and Public Safety Issues: Part 1
Abstract:
The articles in this special section present the most recent advances in amateur drone surveillance network architecture and technologies. The advancement in communication, networking and sensing technologies has attracted researchers, hobbyists, and investors to deploy mini-drones, a.k.a. unmanned air vehicles (UAVs). Drones have boundless viable applications due to their small size and ability to fly without an on-board pilot such as in agriculture, surveillance, and numerous public services. The use of drones for achieving high speed wireless communication is one of the most significant applications for next-generation communication systems (5G). However, their deployment poses several public safety threats to national institutions such as atomic plants, historic places, and the homes of public officials because of their ability to carry explosives and other destructive chemicals. To cope with these security threats, the deployment of surveillance drones is required to monitor amateur drones. The main motivation of deploying surveillance drones is to keep an eye on amateur drones, which can cause serious disasters if no precautionary measures are taken on time. The increasing use of surveillance drones presents challenges such as robust detection, tracking, intruder localization, and jamming. The accuracy of detection is a basic requirement of the system. In general, accurate detection is time-consuming. In fact, a precise moving object detection method makes tracking more reliable and faster, and supports correct classification, which is quite important for surveillance drones to be successful.
Autors: Zeeshan Kaleem;Mubashir Husain Rehmani;Ejaz Ahmed;Abbas Jamalipour;Joel J. P. C. Rodrigues;Hassna Moustafa;Wael Guibene;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2018, volume: 56, issue:1, pages: 14 - 15
Publisher: IEEE
 
» Amine-Functionalized Fe2O3–SiO2 Core–Shell Nanoparticles With Tunable Sizes
Abstract:
Iron oxide magnetic nanoparticles (MNPs) coated with uniform silica shell were synthesized through thermal decomposition and inverse microemulsion methods. The iron oxide MNPs were further coated with silica shells through hydrolysis reaction. For the resulting core–shell MNPs, size regulation of both the magnetic core and the porous shell were achieved, enabling the modulation of their magnetic properties and magnetic interactions. Core–shell MNPs were finally functionalized with amine groups, and immobilized on gold surface due to charge-neutral amine/gold interactions. It was observed that the immobilization process was enhanced under external magnetic field.
Autors: Yun Teng;Chengpeng Jiang;Antonio Ruotolo;Philip W. T. Pong;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jan 2018, volume: 17, issue:1, pages: 69 - 77
Publisher: IEEE
 
» Amplitude and Frequency Estimation of Exponentially Decaying Sinusoids
Abstract:
An online method for amplitude and frequency estimation of exponentially decaying sinusoids is proposed with a moving-window discrete Fourier transform (MWDFT) filter and frequency-locked loop. The tuned filter characteristics of MWDFT is modified into more flat characteristic around the center frequency with negative feedback, which increases the bandwidth of the filter. An adaptive sampling pulse adjustment mechanism is incorporated in the proposed structure for online estimation of frequency. Hence, the frequency error was exploited to achieve synchronization between in-phase component of MWDFT and input signal of estimation. The amplitude is estimated in online from the in-phase and quadrature-phase components of MWDFT. The performance of the proposed method is compared with the existing techniques and experimentally validated on single-link flexible manipulator system for the online estimation of frequency and amplitude of tip deflection signal. The experimental investigation prove that the proposed online technique performs well over the existing techniques.
Autors: Shikha Tomar;Parasuraman Sumathi;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2018, volume: 67, issue:1, pages: 229 - 237
Publisher: IEEE
 

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