Electrical and Electronics Engineering publications abstract of: 05-2017 sorted by title, page: 3

» An Overview of Dynamic-Linearization-Based Data-Driven Control and Applications
Abstract:
A brief overview on the model-based control and data-driven control methods is presented. The data-driven equivalent dynamic linearization, as a foundational analysis tool of data-driven control methods for discrete-time nonlinear systems, is introduced in detail with motivations and distinct features. The prototype model-free adaptive control schemes by using the dynamic linearization to an unknown nonlinear plant model, as well as the alternative model-free adaptive control methods by using the dynamic linearization to an unknown ideal nonlinear controller, are discussed. Furthermore, the extensions of the dynamic linearization to unknown nonlinear repetitive systems and the corresponding model-free adaptive iterative learning control methods are also overviewed and summarized. This work highlights the characteristics and comments of the different model-free adaptive control schemes in detail to facilitate the understanding of the readers. Finally, some perspectives on data-driven control methods in information-rich age are given.
Autors: Zhongsheng Hou;Ronghu Chi;Huijun Gao;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: May 2017, volume: 64, issue:5, pages: 4076 - 4090
Publisher: IEEE
 
» An RF-Powered FDD Radio for Neural Microimplants
Abstract:
We present a radio system that could be used in millimeter-scale wireless neural implants. The system is RF-powered and demonstrates Mbps data rates required for neuromodulation and recording applications. The radio transmits at 58 Mb/s and receives at 2.5 Mb/s maximum data rates. The transceiver uses a duplexer to achieve full-duplex communication via frequency-division duplexing at 1.74 and 1.86 GHz for TX and RX, respectively. The average power consumption of the transmitter is 93 at 58 Mb/s, while that of the receiver is 7.2 at 2.5 Mb/s. The transceiver was fabricated using 40-nm LP CMOS process and occupies 0.8 mm2 of die area. Including the off-chip duplexer, the system occupies 2 1.6 0.6 mm3.
Autors: Yashar Rajavi;Mazhareddin Taghivand;Kamal Aggarwal;Andrew Ma;Ada S. Y. Poon;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: May 2017, volume: 52, issue:5, pages: 1221 - 1229
Publisher: IEEE
 
» An RFID Based Smartphone Proximity Absence Alert System
Abstract:
We present the design, implementation, and evaluation of an RFID-based cellphone anti-lost and anti-theft measure. The cellphone owner is given an audio-visual alert at the very instant of the lost event, and the cellphone deduces the fact that it is away from its owner and executes the safety measures. This is realized by equipping the cellphone with a low-power RFID Reader and tagging the owner with a passive RFID token to determine a private space around him, which spans within 2-10 feet. We prototype an RFID Reader from discrete components under $60 which can transmit 30 dBm with 78 dBm sensitivity, and can also serve as an educational tool for academic learning. Our system works on automatic, timed, or accelerometer based thresholds. We interface our system with Samsung Galaxy Note2 and develop an Android User Interface. We carry out extensive indoor and outdoor experiments under static and dynamic scenarios to ascertain the Frontal and Angular ranges, energy and power consumption, and memory and computational overheads. Our salient contribution is a twofold probing scheme—a duty cycle approach that economizes battery overhead, mitigates false alarms and scans the tag for multiple times by leveraging the interrogation time and power. We argue that though our design is costly in power budget, it is highly economical on battery energy because of short interrogation cycles. We show that for 17 tag interrogations from 20-24 dBm, our scheme consumes 72.1 to 52.4 percent lower energy than a single Bluetooth device scan. For a fully embedded design, we propose System-on-Chip RFID solutions. We foresee our endeavor as a viable proximity absence detection scheme for short range applications and scenarios.
Autors: Muhammad Jawad Hussain;Li Lu;Shan Gao;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: May 2017, volume: 16, issue:5, pages: 1246 - 1257
Publisher: IEEE
 
» An SOI-MEMS Piezoelectric Torsional Stage With Bulk Piezoresistive Sensors
Abstract:
This paper presents a micro-electromechanical stage for out-of-plane positioning of microcantilevers designed for atomic force microscopes. The stage produces an out-of-plane displacement using a torsional mechanism that exploits piezoelectric clamped-guided beams as actuators. To measure the torsional displacement of the stage, novel differential piezoresistive sensors are implemented. These sensors feature clamped-guided beams that exploit the bulk piezoresistivity of silicon. Using this sensing concept eliminates the requirement to fabricate highly doped regions on the flexures. An analytical model is provided that describes the sensor’s linearity. The sensor, the microcantilevers, and the mechanical features of the stage are experimentally characterized. The first resonance frequency of the stage is located at 7.8 kHz, and a static out-of-plane displacement of more than 1.2 is obtained. In addition, the piezoresistive sensor captures the dynamics of the stage within a bandwidth of 13 kHz with a -resolution of 3 nm.
Autors: Mohammad Maroufi;S. O. Reza Moheimani;
Appeared in: IEEE Sensors Journal
Publication date: May 2017, volume: 17, issue:10, pages: 3030 - 3040
Publisher: IEEE
 
» An SQP Method Combined With Gradient Sampling for Small-Signal Stability Constrained OPF
Abstract:
Small-Signal Stability Constrained Optimal Power Flow (SSSC-OPF) can provide additional stability measures and control strategies to guarantee the system to be small-signal stable. However, due to the nonsmooth property of the spectral abscissa function, existing algorithms solving SSSC-OPF cannot guarantee convergence. To tackle this computational challenge of SSSC-OPF, we propose a Sequential Quadratic Programming (SQP) method combined with gradient sampling for SSSC-OPF. At each iteration of the proposed SQP, the gradient of the spectral abscissa function is randomly sampled at the current iterate and additional nearby points to make the search direction computation effective in nonsmooth regions. The method can guarantee SSSC-OPF is globally and efficiently convergent to stationary points with probability one. The effectiveness of the proposed method is tested and validated on WSCC 3-machine 9-bus system, New England 10-machine 39-bus system, and IEEE 54-machine 118-bus system.
Autors: Peijie Li;Junjian Qi;Jianhui Wang;Hua Wei;Xiaoqing Bai;Feng Qiu;
Appeared in: IEEE Transactions on Power Systems
Publication date: May 2017, volume: 32, issue:3, pages: 2372 - 2381
Publisher: IEEE
 
» An Ultra-Low Power 1.7-2.7 GHz Fractional-N Sub-Sampling Digital Frequency Synthesizer and Modulator for IoT Applications in 40 nm CMOS
Abstract:
This paper introduces an ultra-low power 1.7-2.7-GHz fractional-N sub-sampling digital PLL (SS-DPLL) for Internet-of-Things (IoT) applications targeting compliance with Bluetooth Low Energy (BLE) and IEEE802.15.4 standards. A snapshot time-to-digital converter (TDC) acts as a digital sub-sampler featuring an increased out-of-range gain and without any assistance from the traditional counting of DCO edges, thus further reducing power consumption. With a proposed DCO-divider phase rotation in the feedback path, the impact of the digital-to-time converter’s (DTC’s) non-linearity on the PLL is reduced and improves fractional spurs by at least 8 dB across BLE channels. Moreover, a “variable-preconditioned LMS” calibration algorithm is introduced to dynamically correct the DTC gain error with fractional frequency control word (FCW) down to 1/16384. Fabricated in 40 nm CMOS, the SS-DPLL achieves phase noise performance of −109 dBc/Hz at 1 MHz offset, while consuming a record-low power of 1.19 mW.
Autors: Yao-Hong Liu;Johan Van Den Heuvel;Takashi Kuramochi;Benjamin Busze;Paul Mateman;Vamshi Krishna Chillara;Bindi Wang;Robert Bogdan Staszewski;Kathleen Philips;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: May 2017, volume: 64, issue:5, pages: 1094 - 1105
Publisher: IEEE
 
» An Unbounded Frequency Detection Mechanism for Continuous-Rate CDR Circuits
Abstract:
A continuous-rate clock and data recovery (CDR) circuit with unbounded frequency detection mechanism is proposed herein. The unbounded frequency detection mechanism combines the digital quadricorrelator frequency detection and subharmonic tone frequency detection techniques. By adopting the unbounded frequency detector, this reference-less CDR circuit has no locking range limitation and provides an automatically bidirectional frequency detection characteristic. In addition, the CDR circuit can detect the frequency-hopping information without an additional transmitted control signal. Based on the proposed frequency detection methodology, a proof-of-concept CDR circuit is implemented to demonstrate the feasibility and effectiveness of the proposed design.
Autors: Yen-Long Lee;Soon-Jyh Chang;Yen-Chi Chen;Yu-Po Cheng;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: May 2017, volume: 64, issue:5, pages: 500 - 504
Publisher: IEEE
 
» An Upgraded ACA Algorithm in Complex Field and Its Statistical Analysis
Abstract:
An upgraded adaptive cross approximation (U-ACA) algorithm in complex field is proposed, including detailed discussion about both relative-error estimator and pivoting threshold. Two new relative-error estimators are constructed, and the range of the pivoting threshold is determined theoretically. Besides, a statistical analysis of the U-ACA algorithm for computational electromagnetics is provided to identify the credibility of existing relative-error estimators and new ones. The statistical experiments show that the U-ACA algorithm with either of the two new relative-error estimators is a more robust algorithm at present for applications in computational electromagnetics, compared with the previous ACA algorithm.
Autors: Hou-Xing Zhou;Guang-Yu Zhu;Wei-Bin Kong;Wei Hong;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: May 2017, volume: 65, issue:5, pages: 2734 - 2739
Publisher: IEEE
 
» Analysis and Control of a Novel Power Electronics Converter for Active Magnetic Bearing Drive
Abstract:
Magnetic bearing has been developed for high-speed rotational machinery and its power electronics drive is its key technology. In this paper, a novel converter with reduced switches for magnetic bearing drive is described. The principle of the magnetic bearing and its test rig were introduced and graphically illustrated at first. Then, based on the current unidirectional and phase-leg sharing principles, the novel converter topology for magnetic bearing drive together with the current control functions is introduced, including the steady state and dynamic performance. Less power electronics devices are required for this converter in comparison with conventional magnetic bearing drives. Simulation and experimental results have successfully validated the current control capability of magnetic bearing with the proposed converter. With the novel converter and the controller, magnetic bearing can deliver superior levitation and dynamic control performance. In the rotational test, the magnetic bearing has been controlled with position error less than 20% of the air gap up to 24 000 r/min on the test rig.
Autors: Dong Jiang;Parag Kshirsagar;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 2222 - 2232
Publisher: IEEE
 
» Analysis and Design of VCO-Based Phase-Domain $Sigma Delta $ Modulators
Abstract:
VCO-based phase-domain modulators employ the combination of a voltage-controlled-oscillator (VCO) and an up/down counter to replace the analog loop filter used in conventional modulators. Thanks to this highly digital architecture, they can be quite compact, and are expected to shrink even further with CMOS scaling. This paper describes the analysis and design of such converters. Trade-offs between design parameters and the impact of non-idealities, such as finite counter length and VCO non-linearity, are assessed through both theoretical analysis and behavioral simulations. The proposed design methodology is applied to the design of a phase-to-digital converter in a 40-nm CMOS process, which is used to digitize the output of a thermal-diffusivity temperature sensor, achieving ± 0.2° () phase inaccuracy from -40 to 125 °C and a sensor-limited resolution of 57 m° (RMS) within a 500-Hz bandwidth. Measurements on the prototype agree quite well with theoretical predictions, thus demonstrating the validity of the proposed design methodology.
Autors: Uğur Sönmez;Fabio Sebastiano;Kofi A. A. Makinwa;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: May 2017, volume: 64, issue:5, pages: 1075 - 1084
Publisher: IEEE
 
» Analysis Method of Mobile Phone Batteries Remaining State of Charge
Abstract:
The cell phone is among the electronics which have quickly attracted consumers throughout the world with an average usage time of a year and a half, generating with this, a considerable environmental impact. This paper presents a literature review on components of batteries, important factors in battery performance, state of charging and health determination. In this study, through the unloading constant current CC test, it was possible to obtain, in a fast and efficient way, the amount of energy remaining and the state of charge from the lithium-ion mobile batteries discarded by the population, showing that many of the discarded batteries could still be reused as an energy source.
Autors: Eduardo Luis Schneider;Rodolfo de Freitas Valle Dresch;Luiz Tiaraju dos Reis Loureiro;Renato Machado de Brito;
Appeared in: IEEE Latin America Transactions
Publication date: May 2017, volume: 15, issue:5, pages: 854 - 860
Publisher: IEEE
 
» Analysis of a Dual-Rotor, Toroidal-Winding, Axial-Flux Vernier Permanent Magnet Machine
Abstract:
In this paper, a vernier permanent magnet (VPM) machine with dual-rotor toroidal-winding axial-flux topology is analyzed. Through the combination of toroidal windings with the rotor-stator-rotor topology, the end winding length of the proposed machine is significantly reduced compared with that of the regular VPM machine. Based on the airgap permeance function, the back-EMF and torque expressions are derived and the nature of the machine is revealed. The influence of pole ratio (ratio of rotor pole pair number to stator pole pair number) and main geometric parameters, such as slot opening, magnet thickness, etc., on electromagnetic performance is then analytically investigated in detail. Both the quasi-three-dimensional (quasi-3D) finite element analysis (FEA) and 3-D FEA are applied to verify the derived equations. Finally, a prototype of the proposed machine has been manufactured and experimentally evaluated. The test results agree well with both theoretical and FEA analyses. With the current density of 5.8 A/mm 2 and slot fill factor of 0.35, the torque density of the proposed machine prototype can reach 31.9 kNm/m 3.
Autors: Tianjie Zou;Dawei Li;Ronghai Qu;Jian Li;Dong Jiang;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 1920 - 1930
Publisher: IEEE
 
» Analysis of a Statistical Relationship Between Dose and Error Tallies in Semiconductor Digital Integrated Circuits for Application to Radiation Monitoring Over a Wireless Sensor Network
Abstract:
Mass production of widely used semiconductor digital integrated circuits (ICs) has lowered unit costs to the level of ordinary daily consumables of a few dollars. It is therefore reasonable to contemplate the idea of an engineered system that consumes unshielded low-cost ICs for the purpose of measuring gamma radiation dose. Underlying the idea is the premise of a measurable correlation between an observable property of ICs and radiation dose. Accumulation of radiation-damage-induced state changes or error events is such a property. If correct, the premise could make possible low-cost wide-area radiation dose measurement systems, instantiated as wireless sensor networks (WSNs) with unshielded consumable ICs as nodes, communicating error events to a remote base station. The premise has been investigated quantitatively for the first time in laboratory experiments and related analyses performed at the Canadian Nuclear Laboratories. State changes or error events were recorded in real time during irradiation of samples of ICs of different types in a 60Co gamma cell. From the error-event sequences, empirical distribution functions of dose were generated. The distribution functions were inverted and probabilities scaled by total error events, to yield plots of the relationship between dose and error tallies. Positive correlation was observed, and discrete functional dependence of dose quantiles on error tallies was measured, demonstrating the correctness of the premise. The idea of an engineered system that consumes unshielded low-cost ICs in a WSN, for the purpose of measuring gamma radiation dose over wide areas, is therefore tenable.
Autors: Karen Colins;Liqian Li;Yu Liu;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: May 2017, volume: 64, issue:5, pages: 1151 - 1158
Publisher: IEEE
 
» Analysis of Direct-On-Line Synchronous Reluctance Machine Start-Up Using a Magnetic Field Decomposition
Abstract:
Direct-on-line synchronous reluctance machines combine the characteristics of induction machines and synchronous reluctance machines. Saturation of core materials, the eddy currents, and the asymmetry of the rotor core and cage make it difficult to predict which kind of loads a machine can synchronize. In this paper, the start-up of a direct-on-line synchronous reluctance machine is analyzed with a magnetic field decomposition that makes it possible to quantify and isolate forces between any two distinct parts of an electric machine using a transient time-stepping finite element field solution. The results show explicitly which portion of the torque is produced by the rotor core and which by the rotor cage. Compared with conventional average torque analyses (also known as pseudo-constant-speed or quasi-steady-state analyses) used to distinguish between the torque on the rotor core and cage, the proposed method makes no assumptions on the state of the machine. This results in a more detailed view of the starting transient.
Autors: Juha Tampio;Tero Känsäkangas;Saku Suuriniemi;Jere Kolehmainen;Lauri Kettunen;Jouni Ikäheimo;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 1852 - 1859
Publisher: IEEE
 
» Analysis of Dynamic Processes in Single-Cell Electroporation and Their Effects on Parameter Selection Based on the Finite-Element Model
Abstract:
Pulsed electric fields have recently been the focus of considerable attention because of their potential application in biomedicine. However, their practical clinical applications are limited by poor understanding of the interaction mechanism between pulsed electric fields and cells, particularly in the process of electroporation and its effect on parameter selection. This paper established a multishelled dielectric model based on finite elements to simulate and analyze the processes involved in electroporation. In particular, the processes include the dynamic development of the pore radius and electroporation region: the distribution of recoverable, nonrecoverable, and nonelectroporation areas on the cell; and the influence of pulse parameters on varying degrees of electroporation. Results showed that membrane conductivity, pore density, transmembrane potential, and distribution of pore radii are functions of time and position on the cell. The electroporation areas were divided into recoverable, nonrecoverable, and no-electroporation pores. For , 1.5-kV/cm pulse was observed in the regions exposed to sufficiently high transmembrane voltage (1 V), electroporation occurred, membrane conductivity and pore density (up to rapidly increased with time, and electroporation areas increased gradually and were mainly distributed in the range 0°–70° (recoverable pore [0°, 35°], nonrecoverable pore [35°, 70°], and no-electroporation pore [70°, 90°]). Electric field strength was the major factor that induced electroporation, particularly in the recoverable pore, but it had minimal effect on pore- expansion. However, pulse duration affects the nonrecoverable pore, such that the high-intensity wide pulse is more useful in the field of irreversible electroporation. The high-intensity short pulse can increase permeability and maintain cell viability.
Autors: Chenguo Yao;Hongmei Liu;Yajun Zhao;Yan Mi;Shoulong Dong;Yanpeng Lv;
Appeared in: IEEE Transactions on Plasma Science
Publication date: May 2017, volume: 45, issue:5, pages: 889 - 900
Publisher: IEEE
 
» Analysis of Metasurfaces at Oblique Incidence
Abstract:
The theory of analytical modeling of periodic metasurfaces for normal incidence is extended to the general oblique case. The metasurface is considered as a periodic planar array with electrically small dipolar scatterers. The induced polarization currents are calculated by combining the information obtained from the response of individual scatterer to the incident wave and the interaction of scatterers with each other. All required interaction coefficients for the most general analysis of metasurfaces are analytically derived. The expressions in terms of the polarization currents are presented for the reflected/transmitted fields from metasurfaces at oblique illumination. Although theoretically known that adding normal polarization currents to the tangential ones will not provide extra degrees of freedom in the manipulation of the reflection and transmission properties of metasurfaces, in most practical applications, it is required to consider both tangential as well as normal polarization currents. Thus, the effect of oblique illumination in the modification of normal and tangential polarization currents is clarified. Our theory is used to analyze two canonical examples of bianisotropic metasurfaces composed of chiral and omega inclusions. The results of this paper provide an effective tool to push the analysis as well as the synthesis of metasurfaces one step forward.
Autors: Mohammad Yazdi;Mohammad Albooyeh;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: May 2017, volume: 65, issue:5, pages: 2397 - 2404
Publisher: IEEE
 
» Analysis of Proportional Fair Scheduling Under Bursty On-Off Traffic
Abstract:
Proportional fair scheduling (PFS) has been adopted as a standard solution for fair resource allocation in modern wireless cellular networks. With the emergence of heterogeneous networks with widely varying user loads, it is of great importance to characterize the performance of PFS under bursty traffic, which is the case in most wireless streaming and data transfer services. In this letter, we provide the first analytical solution to the performance of PFS under bursty on-off traffic load. We use the Gaussian approximation model to derive a closed-form expression of the achievable user data rates. In order to further improve the accuracy of our baseline analytical solution for multi-cell networks, we design a hybrid approximation by employing multi-interference analysis. The simulation results verify that our model guarantees extremely low data rate estimation error, which is further insensitive to changes in session duration, traffic load and user density.
Autors: Fei Liu;Janne Riihijärvi;Marina Petrova;
Appeared in: IEEE Communications Letters
Publication date: May 2017, volume: 21, issue:5, pages: 1175 - 1178
Publisher: IEEE
 
» Analysis of Recurrent Neural Networks for Probabilistic Modeling of Driver Behavior
Abstract:
The validity of any traffic simulation model depends on its ability to generate representative driver acceleration profiles. This paper studies the effectiveness of recurrent neural networks in predicting the acceleration distributions for car following on highways. The long short-term memory recurrent networks are trained and used to propagate the simulated vehicle trajectories over 10-s horizons. On the basis of several performance metrics, the recurrent networks are shown to generally match or outperform baseline methods in replicating driver behavior, including smoothness and oscillatory characteristics present in real trajectories. This paper reveals that the strong performance is due to the ability of the recurrent network to identify recent trends in the ego-vehicle's state, and recurrent networks are shown to perform as, well as feedforward networks with longer histories as inputs.
Autors: Jeremy Morton;Tim A. Wheeler;Mykel J. Kochenderfer;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: May 2017, volume: 18, issue:5, pages: 1289 - 1298
Publisher: IEEE
 
» Analysis of Spectral and Energy Efficiency Tradeoff in Single-Line Rate WDM Links
Abstract:
This paper investigates, through simulations, the tradeoff between energy efficiency (EE) and the overall spectral efficiency (SE) of fiber optic links for a given capacity and a link length. The comparison is made for various modulation formats, span lengths, and with/without using forward error correction (FEC). The power consumption of the different system components is estimated from the data sheets of the state-of-the-art equipment. Results show that the use of long single-mode fiber spans (i.e., more than 40 km) improves EE when coherent modulation formats are used. However, with noncoherent formats, the span length must be selected depending on SE, aggregated traffic amount needs to be transmitted, and link length. For almost all modulation formats, FEC reduces the overall energy consumption despite being one of the main power consumers in fiber optic communication systems. The power consumption of 3Rs becomes particularly important when the linear crosstalk limits the system reach. In all other cases, the power consumption of transponders and optical line amplifiers is dominating, but their contribution changes depending on the aggregated traffic amount and system reach.
Autors: Aleksejs Udalcovs;Richard Schatz;Lena Wosinska;Paolo Monti;
Appeared in: Journal of Lightwave Technology
Publication date: May 2017, volume: 35, issue:10, pages: 1847 - 1857
Publisher: IEEE
 
» Analysis of Subchannel Correlation in Dual-Polarised MIMO Systems via a Polarisation Diversity Scheme
Abstract:
A polarisation diversity combing scheme for dual-polarised multiple-input and multiple-output channels in small cell environments introduced and evaluated. The scheme is based on post analysis of channel measurement data captured from scenarios and includes indoor-to-indoor, indoor-to-outdoor, and indoor–outdoor–indoor propagation. An analysis of link signal strength and correlation with respect to frequency and polarisation revealed profound differences between copolarised and cross-polarised links in terms of received signal strength and correlation between frequencies. Utilizing these differences, a polarisation diversity combing scheme is evaluated which is shown to produce an average of 10.6-dB polarisation diversity gain.
Autors: Cheng Fang;Enjie Liu;Masood Ur Rehman;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: May 2017, volume: 65, issue:5, pages: 2635 - 2644
Publisher: IEEE
 
» Analysis of Zeros in a Boost DC–DC Converter: State Diagram Approach
Abstract:
This brief presents the analysis of zeros present in boost dc–dc converters that are operating in continuous inductor current mode. It proposes the utilization of the concept of multiple forward pathways from input to output to analyze the origin of the resulting zeros and determine their locations. This brief provides insight into the various zeros present in the boost converter through a state diagram approach.
Autors: Vikas Paduvalli;R. J. Taylor;Poras T. Balsara;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: May 2017, volume: 64, issue:5, pages: 550 - 554
Publisher: IEEE
 
» Analysis on Special Protection Scheme of Korea Electric Power System by Fully Utilizing STATCOM in a Generation Side
Abstract:
Increase in power demand has required providing infrastructure, such as huge power plants and transmission lines. However, the recent trends in power system planning and operation are being toward maximum utilization of existing electricity infrastructure with tight operating margins because of new constraints placed by economic, political, and environmental issues. This might cause serious stability problems when a severe fault or a sudden outage of critical lines occurs. Therefore, the special protection scheme (SPS) has been used by generator tripping and successive load shedding to prevent a large-scale blackout by the cascading effect. If the number of tripping generators in the SPS operation is reduced, the enormous cost of power outage can be saved. This paper analyzes the enhancement of SPS via the transient stability improvement by the static synchronous compensator (STATCOM) applied to a generation side of Korea electric power system. First, its characteristic related to the SPS is described. Then, the proper capacity of STATCOM is determined with the equal area criterion to reduce the number of tripping generators. Also, the new control method for STATCOM is proposed for its full utilization. Finally, its effectiveness is verified by the case study with the practical data of Korea electric power system.
Autors: Dong-Hee Choi;Soo Hyoung Lee;Yong Cheol Kang;Jung-Wook Park;
Appeared in: IEEE Transactions on Power Systems
Publication date: May 2017, volume: 32, issue:3, pages: 1882 - 1890
Publisher: IEEE
 
» Analysis, Prototyping, and Experimental Characterization of an Adaptive Hybrid Electromagnetic Damper for Automotive Suspension Systems
Abstract:
In this paper, the concept of hybrid electromagnetic damping is explored and experimentally evaluated. The aim of the hybrid electromagnetic damping concept is to address the adaptive damping problem in vehicle suspension systems. In order to reach optimal performance, the damping characteristics of the vehicle suspension system must be capable of adaptively increasing or decreasing the amount of energy being absorbed by the system. For the sake of having the requisite functionality of variable damping, a multitude of solutions have been implemented, proposed, and evaluated at both the commercial and academic research levels. These solutions have met the variable damping requirements, but still, there are several crucial drawbacks associated with them. To overcome the shortcomings associated with the aforementioned variable damping solutions, a hybrid design consisting of a conventional hydraulic damper and a linear motor topology is fused together to build a hybrid variable damper. In the proposed hybrid electromagnetic design, the oil in the system acts as bias to provide fail-safe operation for the system, and the linear motor topology allows the requisite variable damping requirement to be achieved with the additional capacity for recovering energy from the system. We present an extended analysis of the electromagnetic damping component of the hybrid damper that can serve as a potent tool for the designers who seek to maximize the adaptability (and regeneration capacity) of the hybrid damper. Afterwards, based on the proposed hybrid electromagnetic concept, the design and fabrication of the first prototype are illustrated. An experimental setup and a test protocol are prepared, and different experiments are conducted to characterize the damping properties of hydraulic and electromagnetic components. Furthermore, friction forces, as well as power capacities, are scrutinized. The results indicate that the hybrid electromagnetic damper prototype is capable of prov- ding a variable damping coefficient in a range of 1302–1540 Ns/m.
Autors: Ehsan Asadi;Roberto Ribeiro;Mir Behrad Khamesee;Amir Khajepour;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 3703 - 3713
Publisher: IEEE
 
» Analytic $JV$ -Characteristics of Ideal Intermediate Band Solar Cells and Solar Cells With Up and Downconverters
Abstract:
The ideal diode equation is regularly used to describe the -characteristic of single junction solar cells. The connection between the diode equation and fundamental physics is the application of the Boltzmann approximation to describe the fluxes of photons emitted by the cell. In this paper, this approximation is used to derive analytic -characteristics for three photovoltaic high-efficiency concepts, intermediate band solar cells, and solar cells optically coupled to up and downconverters. These three concepts share the common feature that they allow excitation of electrons between at least three energy levels, which assures a better utilization of the solar spectrum and leads to limiting efficiencies surpassing the Shockley–Queisser limit. Although being considerablysimpler to implementand use, the resulting -characteristics reproduce the limiting efficiencies obtained from full detailed balancemodels. The simplicity facilitates the intuitive understanding of such devices. The presented models also have the potential to serve as a useful framework for further modeling, through savings in computation time and complexity.
Autors: Rune Strandberg;
Appeared in: IEEE Transactions on Electron Devices
Publication date: May 2017, volume: 64, issue:5, pages: 2275 - 2282
Publisher: IEEE
 
» Analytic Approximations for Real-Time Area Light Shading
Abstract:
We introduce analytic approximations for accurate real-time rendering of surfaces lit by non-occluded area light sources. Our solution leverages the Irradiance Tensors developed by Arvo for the shading of Phong surfaces lit by a polygonal light source. Using a reformulation of the 1D boundary edge integral, we develop a general framework for approximating and evaluating the integral in constant time using simple peak shape functions. To overcome the Phong restriction, we propose a low cost edge splitting strategy that accounts for the spherical warp introduced by the half vector parametrization. Thanks to this novel extension, we accurately approximate common microfacet BRDFs, providing a practical method producing specular stretches that closely match the ground truth in real-time. Finally, using the same approximation framework, we introduce support for spherical and disc area light sources, based on an original polygon spinning method supporting non-uniform scaling operations and horizon clipping. Implemented on a GPU, our method achieves real-time performances without any assumption on area light shape nor surface roughness.
Autors: Pascal Lecocq;Arthur Dufay;Gaël Sourimant;Jean-Eudes Marvie;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: May 2017, volume: 23, issue:5, pages: 1428 - 1441
Publisher: IEEE
 
» Analytic Modeling for Nanoscale Resistive Filament Variation in ReRAM With Stochastic Differential Equation
Abstract:
Nanoscale filament is the active area in oxygen vacancy type resistance random access memory (ReRAM), which is formed stochastically during electric test after being fabricated in a clean room. That is, the filament dimension cannot be controlled with a designed mask pattern. Here, we introduce a formula to describe the current cycle-to-cycle trajectories based on a stochastic differential equation (SDE) with microscopic structure parameters: filament dimension and oxygen vacancy concentration. Since ReRAM conduction follows hopping, the filament can be described by a random resistance network (RRN). The stochastic configuration of an RRN follows the Brownian motion, which is the key parameter in the diffusion of SDE. The formula provides a practically quantitative filament characterization method, which is verified by direct observation of the filament in actual devices. Based on the formula, we can predict ReRAM endurance with the given microscopic structure parameters.
Autors: Zhiqiang Wei;Koji Eriguchi;
Appeared in: IEEE Transactions on Electron Devices
Publication date: May 2017, volume: 64, issue:5, pages: 2201 - 2206
Publisher: IEEE
 
» Analytical and Experimental Investigations on Mitigation of Interference in a DBF MIMO Radar
Abstract:
As driver assistance systems and autonomous driving are on the rise, radar sensors become a common device for automobiles. The high sensor density leads to the occurrence of interference, which decreases the detection capabilities. Here, digital beamforming (DBF) is applied to mitigate such interference. A DBF system requires a calibration of the different receiving channels. It is shown how this calibration completely changes the DBF beam pattern required to cancel interferences, if the system has no IQ receiver. Afterward, the application of DBF on a multiple-input multiple-output (MIMO) radar is investigated. It is shown that only the real aperture and not the virtual one can be used for interference suppression, leading to wide notches in the pattern. However, for any target the large virtual aperture can be exploited, even if interferers are blinded out. Moreover, the wide notches for interference suppression of the real aperture appear narrow in the virtual aperture for target localization. The results are verified by measurements with time-multiplexing MIMO radar.
Autors: Jonathan Bechter;Muhammad Rameez;Christian Waldschmidt;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: May 2017, volume: 65, issue:5, pages: 1727 - 1734
Publisher: IEEE
 
» Analytical Expressions for Joint Distributions in Probabilistic Load Flow
Abstract:
Adopting the Gaussian mixture model, we derive an analytical expression for the joint probability density function of active power on multiple transmission lines, in the presence of non-Gaussian stochastic power injections. The corresponding joint cumulative distribution function is further obtained by multiple integrals. Results of the proposed method coincide with that of Monte Carlo simulations.
Autors: Zhiwen Wang;Chen Shen;Feng Liu;Feng Gao;
Appeared in: IEEE Transactions on Power Systems
Publication date: May 2017, volume: 32, issue:3, pages: 2473 - 2474
Publisher: IEEE
 
» Analytical Methods for Characterizing Frequency Dynamics in Islanded Microgrids With Gensets and Energy Storage
Abstract:
Microgrids with increased penetration of renewables experience serious challenges due to large frequency excursions under power system disturbances. An energy storage system can provide frequency regulation, but the effectiveness depends on whether it is configured for the grid-forming or grid-following mode of operation. For this purpose, two critical parameters are studied for frequency regulation in distribution systems; first, the initial rate-of-change-of-frequency (ROCOF), and second, the minimum value of frequency, also known as frequency nadir, following a load change. The aim of this paper is to identify analytical methods for accurately calculating the frequency parameters like ROCOF and frequency nadir. Reduced-order models are developed to determine the frequency deviation against power system disturbances. The results are verified against simulation models validated by testing at the Consortium for Electric Reliability Technology Solutions Microgrid test bed.
Autors: Ajit A. Renjit;Abrez Mondal;Mahesh S. Illindala;Amrit S. Khalsa;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 1815 - 1823
Publisher: IEEE
 
» Analytical Model of Mid-Infrared Surface Plasmon Modes in a Cylindrical Long-Range Waveguide With Double-Layer Graphene
Abstract:
An optical waveguide for working in mid-infrared range is highly desirable. However, such a waveguide is required to yield a long propagation distance and deep subwavelength confinement. Although the graphene-based surface plasmon polariton (SPP) waveguides have exhibited some potential in this regard, their propagation lengths are currently insufficient (∼100 μm). In this paper, we propose a graphene-based cylindrical long-range SPP (LRSPP) waveguide, which is composed of a cylindrical silicon nanowire core surrounded by an inner graphene layer, a silica layer, and an outer graphene layer from inside to out. First, the electromagnetic field equation and the dispersion equation of this waveguide are derived. Then, combining these derived equations with the numerical simulation, the propagation properties of the LRSPP and the short-range SPP modes are analyzed. The results show that the proposed waveguide with the LRSPP fundamental mode has a notable advantage for simultaneously achieving a larger propagation length (∼10 μm) and a deep subwavelength confinement (, where is the diffraction-limited mode area). This waveguide has potential for application in high-density photonic integrated circuits in the mid-infrared range.
Autors: Jian-Ping Liu;Xiang Zhai;Fang Xie;Ling-Ling Wang;Sheng-Xuan Xia;Hong-Ju Li;Xin Luo;Xiong-Jun Shang;
Appeared in: Journal of Lightwave Technology
Publication date: May 2017, volume: 35, issue:10, pages: 1971 - 1979
Publisher: IEEE
 
» Analytical Modeling of Interturn Short Circuit for Multiphase Fault-Tolerant PM Machines With Fractional Slot Concentrated Windings
Abstract:
Interturn short-circuit faults that occur inside stator coils are difficult to cope with compared with terminal short-circuit faults. A general analytical model for interturn short-circuit faults is developed that employs a novel T-type equivalent circuit. When this model is used to investigate the impact of interturn short-circuit faults in permanent-magnet (PM) machines with fractional slot concentrated windings (FSCW), the model delivers fault response predictions that agree very well with results from the finite element analysis. The model is used to show that the 24-slot/14-pole FSCW PM machine is vulnerable to very high interturn fault currents, even when the remaining turns are shorted, offsetting its advantage of low magnetic coupling between phases. FSCW-PM machines that employ aligned coils in phase windings can effectively suppress their interturn fault currents. Experimental verifications are provided for the 24-slot/22-pole FSCW PM prototype machine (with two aligned coils per phase) under the single-turn short-circuit fault.
Autors: Fan Wu;Ping Zheng;Thomas M. Jahns;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 1994 - 2006
Publisher: IEEE
 
» Analytical Prediction of Magnetic Field Distribution in Spoke-Type Permanent-Magnet Synchronous Machines Accounting for Bridge Saturation and Magnet Shape
Abstract:
This paper presents an analytical model for the prediction of magnetic field distribution in spoke-type permanent-magnet synchronous machines with rectangular magnets and magnetic bridges. The influence of saturation is considered. The magnetic bridges are equivalent to fan-shaped saturation regions. On the basis of the same pole-arc angle and identical magnetic energy, one rectangular magnet is simplified to two fan-shaped regions. The entire field domain is divided into eight types of simple subdomains, i.e., shaft, inner magnetic bridge, inner fan-shaped magnet, outer fan-shaped magnet, outer magnetic bridge, air gap, slot opening, and slot. The effect of magnetic field caused by armature reaction on the saturation of magnetic bridges is considered. The analytical expression of each subdomain is derived and the field solution is obtained by the boundary conditions. The analytical results at the no-load and on-load conditions are verified with the finite-element method.
Autors: Peixin Liang;Feng Chai;Yi Li;Yulong Pei;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: May 2017, volume: 64, issue:5, pages: 3479 - 3488
Publisher: IEEE
 
» Analytical Rotor Position Estimation for SRM Based on Scaling of Reluctance Characteristics From Torque-Balanced Measurement
Abstract:
In this paper, a novel analytical method is proposed for rotor position estimation of switched reluctance machine (SRM). The nonlinear reluctance characteristic of the SRM is divided into two parts, namely air gap and iron core, and analyzed in detail from the aspect of magnetic field. According to the inherent features of the reluctance characteristic, it is analytically expressed based on scaling. Two segments are considered, which are expressed as a linear function and a quadratic function, respectively. Then, the analytical expressions of rotor position are derived for each segment. The effectiveness of the proposed analytical estimation method is evaluated with detailed simulations and experiments under different operating conditions. The proposed method is accurate and just requires the reluctance characteristic at four or even two rotor positions, which can be conveniently measured by the torque-balanced method.
Autors: Shoujun Song;Shuo Chen;Weiguo Liu;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: May 2017, volume: 64, issue:5, pages: 3524 - 3536
Publisher: IEEE
 
» Analyzing Eye-Tracking Information in Visualization and Data Space: From Where on the Screen to What on the Screen
Abstract:
Eye-tracking data is currently analyzed in the image space that gaze-coordinates were recorded in, generally with the help of overlays such as heatmaps or scanpaths, or with the help of manually defined areas of interest (AOI). Such analyses, which focus predominantly on where on the screen users are looking, require significant manual input and are not feasible for studies involving many subjects, long sessions, and heavily interactive visual stimuli. Alternatively, we show that it is feasible to collect and analyze eye-tracking information in data space. Specifically, the visual layout of visualizations with open source code that can be instrumented is known at rendering time, and thus can be used to relate gaze-coordinates to visualization and data objects that users view, in real time. We demonstrate the effectiveness of this approach by showing that data collected using this methodology from nine users working with an interactive visualization, was well aligned with the tasks that those users were asked to solve, and similar to annotation data produced by five human coders. Moreover, we introduce an algorithm that, given our instrumented visualization, could translate gaze-coordinates into viewed objects with greater accuracy than simply binning gazes into dynamically defined AOIs. Finally, we discuss the challenges, opportunities, and benefits of analyzing eye-tracking in visualization and data space.
Autors: Sayeed Safayet Alam;Radu Jianu;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: May 2017, volume: 23, issue:5, pages: 1492 - 1505
Publisher: IEEE
 
» Anatomical Directional Dissimilarities in Tri-axial Swallowing Accelerometry Signals
Abstract:
Swallowing accelerometry is a noninvasive approach currently under consideration as an instrumental screening test for swallowing difficulties, with most current studies focusing on the swallowing vibrations in the anterior–posterior (A-P) and superior–inferior (S-I) directions. However, the displacement of the hyolaryngeal structure during the act of swallowing in patients with dysphagia involves declination of the medial–lateral (M-L), which suggests that the swallowing vibrations in the M-L direction have the ability to reveal additional details about the swallowing function. With this motivation, we performed a broad comparison of the swallowing vibrations in all three anatomical directions. Tri-axial swallowing accelerometry signals were concurrently collected from 72 dysphagic patients undergoing videofluoroscopic evaluation of swallowing (mean age: 63.94 ± 12.58 years period). Participants swallowed one or more thickened liquids with different consistencies including thin–thick liquids, nectar-thick liquids, and pudding-thick liquids with either a comfortable self-selected volume from a cup or a controlled volume by the examiner from a 5-ml spoon. Swallows were grouped based on the viscosity of swallows and the participant’s stroke history. Then, a comprehensive set of features was extracted in multiple signal domains from 881 swallows. The results highlighted inter-axis dissimilarities among tri-axial swallowing vibrations including the extent of variability in the amplitude of signals, the degree of predictability of signals, and the extent of disordered behavior of signals in time-frequency domain. First, the upward movement of the hyolaryngeal structure, representing the S-I signals, were actually more variable in amplitude and showed less predictable behavior than the sideways and forward movements, representing the A-P and M-L signals, duri- g swallowing. Second, the S-I signals, which represent the upward movement of the hyolaryngeal structure, behaved more disordered in the time-frequency domain than the sideways movement, M-L signals, in all groups of study except for the pudding swallows in the stroke group. Third, considering the viscosity and the participant’s pathology, thin liquid swallows in the nonstroke group presented the most directional differences among all groups of study. In summary, despite some directional dissimilarities, M-L axis accelerometry characteristics are similar to those of the two other axes. This indicates that M-L axis characteristics, which cannot be observed in videofluoroscopic images, can be adequately derived from the A-P and S-I axes.
Autors: Faezeh Movahedi;Atsuko Kurosu;James L. Coyle;Subashan Perera;Ervin Sejdić;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: May 2017, volume: 25, issue:5, pages: 447 - 458
Publisher: IEEE
 
» Angled 3D Glass-to-Silicon Photonics Coupling Interface
Abstract:
A numerical study on the design of a novel low-loss, low-cost, and low fabrication complexity, angled 3D Glass-to-SiPh coupling interface is demonstrated. The interface is composed of a 2° angled 3D glass waveguide and a thin-silicon-on-insulator platform flip-chip assembled in close proximity. The overall structure is designed and optimized based on the maximization of the coupling strength ( as well as the calculation of a constant loss taper (CLT) silicon taper. The reported maximum conversion efficiency is 85.7% for 1.55- central wavelength and is almost flat across the entire -band. The results were obtained using a 3D eigenmode expansion (3D-EME) propagation solver and were verified through the 3D finite-difference time-domain (3D-FDTD) simulation method.
Autors: G. Poulopoulos;D. Kalavrouziotis;J. R. Macdonald;P. Mitchell;N. Psaila;H. Avramopoulos;
Appeared in: IEEE Photonics Technology Letters
Publication date: May 2017, volume: 29, issue:9, pages: 763 - 766
Publisher: IEEE
 
» Anomaly Detection in Traffic Scenes via Spatial-Aware Motion Reconstruction
Abstract:
Anomaly detection from a driver's perspective when driving is important to autonomous vehicles. As a part of Advanced Driver Assistance Systems (ADAS), it can remind the driver about dangers in a timely manner. Compared with traditional studied scenes such as a university campus and market surveillance videos, it is difficult to detect an abnormal event from a driver's perspective due to camera waggle, abidingly moving background, drastic change of vehicle velocity, etc. To tackle these specific problems, this paper proposes a spatial localization constrained sparse coding approach for anomaly detection in traffic scenes, which first measures the abnormality of motion orientation and magnitude, respectively, and then fuses these two aspects to obtain a robust detection result. The main contributions are threefold, as follows. 1) This work describes the motion orientation and magnitude of the object, respectively, in a new way, which is demonstrated to be better than the traditional motion descriptors. 2) The spatial localization of an object is taken into account considering the sparse reconstruction framework, which utilizes the scene's structural information and outperforms the conventional sparse coding methods. 3) Results of motion orientation and magnitude are adaptively weighted and fused by a Bayesian model, which makes the proposed method more robust and able to handle more kinds of abnormal events. The efficiency and effectiveness of the proposed method are validated by testing on nine difficult video sequences that we captured ourselves. Observed from the experimental results, the proposed method is more effective and efficient than the popular competitors and yields a higher performance.
Autors: Yuan Yuan;Dong Wang;Qi Wang;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: May 2017, volume: 18, issue:5, pages: 1198 - 1209
Publisher: IEEE
 
» Antenna Cross-Polar Requirements for 3-PolD Weather Radar Measurements
Abstract:
The analysis and correction of the bias occurring in weather radar polarimetric measurements is a challenging problem. Polarization coupling due to the cross-polar radiation pattern of the radar's antenna is known to be responsible for errors in the estimation of the polarimetric covariance matrix, and consequently in the hydrometeor classification and quantification, either when using the ATSR or the SHV method. An alternative method for Doppler and polarimetric measurements based on transmitting three different polarizations (3-PolD) has been proven to provide accurate polarimetric covariance matrix estimates without making any hypothesis about the target polarimetric response or its Doppler spectrum. This method does not reduce the Doppler capabilities or the unambiguous range of the radar despite alternately transmitting 3-PolD. These characteristics have encouraged evaluating the polarimetric parameter biases due to cross-polar radiation when this method is used. Biases are calculated considering reflector antenna systems as well as phased-array antenna systems. The results show that this method may guarantee a tolerable bias level even with a poor co- to cross-polar antenna pattern ratio.
Autors: José M. Pidre;María Vera Isasa;Verónica Santalla del Río;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: May 2017, volume: 55, issue:5, pages: 2682 - 2692
Publisher: IEEE
 
» Antenna Selection in MIMO Cognitive AF Relay Networks With Mutual Interference and Limited Feedback
Abstract:
This letter studies antenna selection in amplify-and-forward multiple-input multiple-output cooperative cognitive radio system under mutual primary-secondary interference. Two power allocation methods are adopted at the secondary transmitters, assuming perfect and limited feedback from the primary receiver. For both methods, outage, and error performance analysis is conducted, where simple, closed-form expressions are derived over Rayleigh fading channels. In addition, asymptotic analysis is performed to get insights about the diversity gain and the effects of key parameters, including the primary receiver feedback and the number of the antennas. Our analytical results, which are validated with simulations, show the effective impact of the proposed model on enhancing the overall system performance.
Autors: Eylem Erdogan;Ali Afana;Salama Ikki;Halim Yanikomeroglu;
Appeared in: IEEE Communications Letters
Publication date: May 2017, volume: 21, issue:5, pages: 1111 - 1114
Publisher: IEEE
 
» Antenna Selection in RF-Chain-Limited MIMO Interference Networks Under Interference Alignment
Abstract:
In multiple-input multiple-output (MIMO) systems, the deployment of multiple radio-frequency (RF) chains is much more expensive than that of multiple antennas. Antenna selection (AS) is a low-cost low-complexity method to exploit the diversity gain in MIMO systems with sufficient antennas but limited RF chains. Among the AS algorithms, decremental AS has been shown to be near-optimal compared with exhaustive search. In this paper, we study AS in MIMO interference networks applying the interference alignment (IA) scheme. IA aligns and zero-forces the interference via transmitter–receiver beamforming and achieves a maximum degree of freedom. The feasibility and alignment topology of IA is dependent on the active antenna configuration. For users in tightly feasible systems, IA can be resumed after AS by adapting the beamformers locally, and the exact transmission rate can be known. For users in superfeasible systems, we derive the expected rate under IA conditioned on local channel state information (CSI). Adopting the rate or expected rate as selection criterion, we propose the decremental AS algorithms achieving a twofold complexity reduction. Simulation results and complexity analysis show that the algorithms achieve near-optimal performance at low complexity.
Autors: Mengjie Xie;Tat-Ming Lok;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 3856 - 3870
Publisher: IEEE
 
» Application of Infrared Thermography to Failure Detection in Industrial Induction Motors: Case Stories
Abstract:
Infrared thermography has been extensively applied over decades to areas such as maintenance of electrical installations. Its use in electrical machinery has been mainly circumscribed to the detection of faults in static machines, such as power transformers. However, with regard to the predictive maintenance of rotating electrical machines, its use has been much more limited. In spite of this fact, the potential of this tool, together with the progressive decrease in the price of infrared cameras, makes this technique a very interesting option to at least complement the diagnosis provided by other well-known techniques, such as current or vibration data analysis. In this context, infrared thermography has recently shown potential for the detection of motor failures including misalignments, cooling problems, bearing damages, or connection defects. This work presents several industrial cases that help to illustrate the effectiveness of this technique for the detection of a wide range of faults in field induction motors. The data obtained with this technique made it possible to detect the presence of faults of diverse nature (electrical, mechanical, thermal, and environmental); these data were very useful to either diagnose or complement the diagnosis provided by other tools.
Autors: David López-Pérez;Jose Antonino-Daviu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 1901 - 1908
Publisher: IEEE
 
» Application of the Thermal Fin Approximation to Modeling Voice Coil Magnetic Fields and Performance
Abstract:
This paper develops an approximate analytical model to describe the magnetic fluxes, forces, and armature reaction in cylindrical voice coil actuators and related electric machines. Magnetic flux is assumed to either lie in an inner region of the actuator and parallel to its axis, or in an outer region of the actuator and oriented radially. A differential reluctance model is derived for this set of assumptions, with a structure and solution set similar to those involved in extended-surface heat transfer (“fins”) and lossy transmission lines. Particular solutions for the force constant, motor constant, coil inductance, and variable-reluctance force are found for a symmetric motor with opposed axial permanent magnets on either side of an iron flux concentrator. The model results for this topology are validated using finite-element analysis and experimental measurements from a prototype.
Autors: Bryan P. Ruddy;
Appeared in: IEEE Transactions on Magnetics
Publication date: May 2017, volume: 53, issue:5, pages: 1 - 8
Publisher: IEEE
 
» Application of VPM for Scattering From Tapered Cylindrical Components of Vegetation
Abstract:
To advance the investigation of vegetated terrain using polarimetric remote sensing techniques, it is important to determine the electromagnetic properties of key constituents, such as branches and trunks, which may be realistically modeled by tapered cylinders. To this end, we apply our previously proposed virtual partition method (VPM). Numerical simulations demonstrate that VPM possesses the desired features, such as high fidelity prediction of the scattering amplitude function and fulfillment of energy conservation as well as the reciprocity theorem. It thus may be helpful in the pursuit of better coherent scattering models of vegetated terrain, a finer understanding of PolInSAR imagery, and a better characterization of scattering mechanisms.
Autors: Chao Yang;Yang Du;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 654 - 658
Publisher: IEEE
 
» Apply or Die: On the Role and Assessment of Application Papers in Visualization
Abstract:
Application-oriented papers provide an important way to invigorate and cross-pollinate the visualization field, but the exact criteria for judging an application paper's merit remain an open question. This article builds on a panel at the 2016 IEEE Visualization Conference entitled "Application Papers: What Are They, and How Should They Be Evaluated?" that sought to gain a better understanding of prevalent views in the visualization community. This article surveys current trends that favor application papers, reviews the benefits and contributions of this paper type, and discusses their assessment in the review process. It concludes with recommendations to ensure that the visualization community is more inclusive to application papers.
Autors: Gunther H. Weber;Sheelagh Carpendale;David Ebert;Brian Fisher;Hans Hagen;Ben Shneiderman;Anders Ynnerman;
Appeared in: IEEE Computer Graphics and Applications
Publication date: May 2017, volume: 38, issue:3, pages: 96 - 104
Publisher: IEEE
 
» Approaches to Co-Evolution of Metamodels and Models: A Survey
Abstract:
Modeling languages, just as all software artifacts, evolve. This poses the risk that legacy models of a company get lost, when they become incompatible with the new language version. To address this risk, a multitude of approaches for metamodel-model co-evolution were proposed in the last 10 years. However, the high number of solutions makes it difficult for practitioners to choose an appropriate approach. In this paper, we present a survey on 31 approaches to support metamodel-model co-evolution. We introduce a taxonomy of solution techniques and classify the existing approaches. To support researchers, we discuss the state of the art, in order to better identify open issues. Furthermore, we use the results to provide a decision support for practitioners, who aim to adopt solutions from research.
Autors: Regina Hebig;Djamel Eddine Khelladi;Reda Bendraou;
Appeared in: IEEE Transactions on Software Engineering
Publication date: May 2017, volume: 43, issue:5, pages: 396 - 414
Publisher: IEEE
 
» Approximate MMSE Estimator for Linear Dynamic Systems With Gaussian Mixture Noise
Abstract:
In this work, we propose an approximate minimum mean-square error filter for linear dynamic systems with Gaussian Mixture (GM) noise. The proposed estimator tracks each component of the GM posterior with an individual filter and minimizes the trace of the covariance matrix of the bank of filters, as opposed to minimizing the MSE of individual filters filters in the commonly used Gaussian sum filter (GSF). Hence, the spread of means in the proposed method is smaller than that of GSF which makes it more robust to removing components. Consequently, reduction schemes with lower computational complexity can be used with the proposed filter without losing estimation accuracy and precision. This is supported through simulations on synthetic data as well as experimental data related to an indoor localization system. Additionally, we show that in two limit cases the state estimation provided by our proposed method converges to that of GSF, and we provide simulation results supporting this in other cases.
Autors: Leila Pishdad;Fabrice Labeau;
Appeared in: IEEE Transactions on Automatic Control
Publication date: May 2017, volume: 62, issue:5, pages: 2457 - 2463
Publisher: IEEE
 
» Arc Fault Detection Method Based on CZT Low-Frequency Harmonic Current Analysis
Abstract:
This paper presents a method for the detection of series arc faults in electrical circuits, which has been developed starting from an experimental characterization of the arc fault phenomenon and an arcing current study in several test conditions. Starting from this, the authors have found that is it possible to suitably detect arc faults by means of a high-resolution low-frequency harmonic analysis of current signal, based on chirp zeta transform, and a proper set of indicators. The proposed method effectiveness is shown by means of experimental tests, which were carried in both arcing and nonarcing conditions and in the presence of different loads, chosen according to the UL 1699 standard requirements.
Autors: Giovanni Artale;Antonio Cataliotti;Valentina Cosentino;Dario Di Cara;Salvatore Nuccio;Giovanni Tinè;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: May 2017, volume: 66, issue:5, pages: 888 - 896
Publisher: IEEE
 
» Arc-Flash Mitigation: A Systematic Approach for Company Standard Power System Schemes
Abstract:
Arc-flash hazard assessment studies involving a very large oil and gas company's equipment rated 38 kV and below revealed locations with excessive arcflash incident energy. After conducting many additional studies of power distribution systems for various plants (e.g., refineries, gas plants, gas-oil separation plants, and natural gas liquid plants), we realized that dangerous locations (greater than 40 cal/cm<sup>2</sup>) are somewhat consistent among various plant types. This knowledge makes planning and budgeting for implementing arc-flash mitigation predictable from a corporate perspective. Specific arc-flash mitigation techniques can be embedded in the specifications of new projects as well as company material standards to avoid unnecessary retrofit activities after installation. Maintenance personnel can also be effectively trained on arc-flash mitigation and safe work practices when consistent solutions are implemented. This article demonstrates a systematic approach to address dangerous arc-flash locations for corporate planning purposes and provides practical mitigation solutions that can be applied at many company facilities.
Autors: Rakan El-Mahayni;Jamal Bugshan;Ritchie Pragale;
Appeared in: IEEE Industry Applications Magazine
Publication date: May 2017, volume: 23, issue:3, pages: 24 - 32
Publisher: IEEE
 
» Architectural Principles for Energy-Aware Internet-Scale Applications
Abstract:
Optimizing the energy consumption of today's Internet-scale systems will require a radical approach that considers the whole system. To address system-level energy efficiency, software architects can follow three simple design principles. A case study illustrates the possible savings.
Autors: Rabih Bashroush;Eoin Woods;
Appeared in: IEEE Software
Publication date: May 2017, volume: 34, issue:3, pages: 14 - 17
Publisher: IEEE
 
» Are There Many Real Innovators Nowadays?
Abstract:
Academia struggles to produce innovative work leading to highimpact publications. In the meantime, the goal of every researcher is to make as significant an impact as is possible, gauged mainly by a high number of citations. Another parameter is the visibility of the conferences or journals that researchers choose to publish their findings.
Autors: Vasileios Theodosiadis;
Appeared in: IEEE Potentials
Publication date: May 2017, volume: 36, issue:3, pages: 41 - 43
Publisher: IEEE
 
» ARFTG 2017
Abstract:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Autors: Peter H. Aaen;Nick Ridler;
Appeared in: IEEE Microwave Magazine
Publication date: May 2017, volume: 18, issue:3, pages: 98 - 100
Publisher: IEEE
 
» ASRQ: Automatic Segment Repeat Request for IEEE 802.15.4-Based WBAN
Abstract:
In a wireless body area network (WBAN), high data reliability and long operating time are important requirements. The retransmission process of the default Automatic Repeat reQuest (ARQ) mechanism in IEEE 802.15.4 is a suitable method to ensure the data reliability of WBAN communications, where frame loss can occur frequently. However, retransmitting the entire DATA frame is energy inefficient due to the fact that the most of payload data within lost frames are only partially corrupted. Therefore, this paper proposes the automatic segment repeat request scheme for the IEEE 802.15.4-based WBANs. The proposed scheme partitions the data payload into segments when the channel condition is bad, and retransmits only the corrupted segment(s). This reduces the size of the retransmitted frames, which improves frame reception rate and decreases the amount of transmitted traffic, and thus energy consumption. Our experiments using a real IEEE 802.15.4-based WBAN test bed show that the proposed method provides higher transmission reliability and lower power consumption than the default IEEE 802.15.4 ARQ mechanism.
Autors: Byoungseon Kim;Ben Lee;Jinsung Cho;
Appeared in: IEEE Sensors Journal
Publication date: May 2017, volume: 17, issue:9, pages: 2925 - 2935
Publisher: IEEE
 
» Assessment of the Electrical Performance of Short Channel InAs and Strained Si Nanowire FETs
Abstract:
We present a numerical study aimed to benchmark short gate InAs nanowire-FETs (NW-FETs) against their strained Si (sSi) counterpart. Our full-quantum simulations focus on both gate-length scaling and device variability and include the impact of electron–phonon scattering and surface roughness (SR). Interestingly, we found that SR improves the subthreshold-voltage swing (SS) of short gate-length InAs devices by inducing a reduced source-to-drain tunneling. Hence, InAs NW-FETs exhibit a larger immunity to the roughness-induced degradation of the ON-current, whereas they suffer froma larger OFF-current and SS variabilitywith respect to the sSi ones. According to our results, InAs NW-FETs could compete with sSi NW-FETs only for very short gate lengths, when the device performance is significantly degraded, while for longer devices sSi NW-FETs remain a more effective and reliable choice due to the higher gate overdrive charge.
Autors: Corentin Grillet;Demetrio Logoteta;Alessandro Cresti;Marco G. Pala;
Appeared in: IEEE Transactions on Electron Devices
Publication date: May 2017, volume: 64, issue:5, pages: 2425 - 2431
Publisher: IEEE
 
» Asymmetric Junctions in Metallic–Semiconducting–Metallic Heterophase MoS2
Abstract:
Symmetry of the source–channel and drain–channel junction is a unique property of a metal-oxide-semiconductor field effect transistor (MOSFET), which needs to be preserved while realizing sub-decananometer channel length devices using advanced technology. Employing experimental-findings-driven atomistic modeling techniques, we demonstrate that such symmetry might not be preserved in an atomically thin phase-engineered MoS2-based MOSFET. It originates from the two distinct atomic patterns at phase boundaries ( and *) when the semiconducting phase (channel) is sandwiched between the two metallic phases (source and drain). We develop a geometrically optimized atomic model of two independent heterophase structures comprising and * interfaces and study their electrical characteristics using density functional theory-nonequilibriumGreen’s function formalism. We further study the effect of semiconductor doping on the transmission of those planar devices and show that irrespective of the doping concentration, these heterophase structures exhibit asymmetric barrier heights. Our findings could be useful for designing integrated circuits using such advanced transistors.
Autors: Dipankar Saha;Santanu Mahapatra;
Appeared in: IEEE Transactions on Electron Devices
Publication date: May 2017, volume: 64, issue:5, pages: 2457 - 2460
Publisher: IEEE
 
» Asymptotic Stability of Perturbation-Based Extremum-Seeking Control for Nonlinear Plants
Abstract:
We introduce a perturbation-based extremum-seeking controller for general nonlinear dynamical plants with an arbitrary number of tunable plant parameters. The controller ensures asymptotic convergence of the plant parameters to their performance-optimizing values for any initial plant condition under the assumptions in this work. The key to this result is that the amplitude and the frequencies of the perturbations, as well as other tuning parameters of the controller, are time varying. Remarkably, the time-varying tuning parameters can be chosen such that asymptotic convergence is achieved for all plants that satisfy the assumptions, thereby guaranteeing stability of the resulting closed-loop system of plant and controller regardless of tuning.
Autors: Mark Haring;Tor Arne Johansen;
Appeared in: IEEE Transactions on Automatic Control
Publication date: May 2017, volume: 62, issue:5, pages: 2302 - 2317
Publisher: IEEE
 
» Asynchronous Distributed Optimization Via Randomized Dual Proximal Gradient
Abstract:
In this paper we consider distributed optimization problems in which the cost function is separable, i.e., a sum of possibly non-smooth functions all sharing a common variable, and can be split into a strongly convex term and a convex one. The second term is typically used to encode constraints or to regularize the solution. We propose a class of distributed optimization algorithms based on proximal gradient methods applied to the dual problem. We show that, by choosing suitable primal variable copies, the dual problem is itself separable when written in terms of conjugate functions, and the dual variables can be stacked into non-overlapping blocks associated to the computing nodes. We first show that a weighted proximal gradient on the dual function leads to a synchronous distributed algorithm with local dual proximal gradient updates at each node. Then, as main paper contribution, we develop asynchronous versions of the algorithm in which the node updates are triggered by local timers without any global iteration counter. The algorithms are shown to be proper randomized block-coordinate proximal gradient updates on the dual function.
Autors: Ivano Notarnicola;Giuseppe Notarstefano;
Appeared in: IEEE Transactions on Automatic Control
Publication date: May 2017, volume: 62, issue:5, pages: 2095 - 2106
Publisher: IEEE
 
» Attention-Weighted Texture and Depth Bit-Allocation in General-Geometry Free-Viewpoint Television
Abstract:
In a free-viewpoint television network, each viewer chooses its point of view from which to watch a scene. We use the concept of total observed distortion, wherein we aim to minimize the distortion of the view observed by the viewers as opposed to the distortion of each camera, to develop an optimized bit-rate allocation for each camera. Our attention-weighted approach effectively gives more bits to the cameras that are more watched. The more concentrated the viewer distribution, the larger the bit-rate savings, for a given total observed distortion, compared with the uniform rate allocation. We analyze and model the distortion of a synthesized view as a function of the distortions (both in texture and/or depth) of the nearby cameras. Based on such models, we develop optimal rate-allocation methods for texture images, considering a uniform bit allocation for depth, and for both texture and depth simultaneously. Simulation results are shown, demonstrating not only the correctness of the optimized solution, but also measuring its improvement against uniform rate allocation for a few viewer distributions.
Autors: Camilo Dorea;Ricardo L. de Queiroz;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: May 2017, volume: 27, issue:5, pages: 1055 - 1065
Publisher: IEEE
 
» Attentive Contexts for Object Detection
Abstract:
Modern deep neural network-based object detection methods typically classify candidate proposals using their interior features. However, global and local surrounding contexts that are believed to be valuable for object detection are not fully exploited by existing methods yet. In this work, we take a step towards understanding what is a robust practice to extract and utilize contextual information to facilitate object detection in practice. Specifically, we consider the following two questions: “how to identify useful global contextual information for detecting a certain object?” and “how to exploit local context surrounding a proposal for better inferring its contents?” We provide preliminary answers to these questions through developing a novel attention to context convolution neural network (AC-CNN)-based object detection model. AC-CNN effectively incorporates global and local contextual information into the region-based CNN (e.g., fast R-CNN and faster R-CNN) detection framework and provides better object detection performance. It consists of one attention-based global contextualized (AGC) subnetwork and one multi-scale local contextualized (MLC) subnetwork. To capture global context, the AGC subnetwork recurrently generates an attention map for an input image to highlight useful global contextual locations, through multiple stacked long short-term memory layers. For capturing surrounding local context, the MLC subnetwork exploits both the inside and outside contextual information of each specific proposal at multiple scales. The global and local context are then fused together for making the final decision for detection. Extensive experiments on PASCAL VOC 2007 and VOC 2012 well demonstrate the superiority of the proposed AC-CNN over well-established baselines.
Autors: Jianan Li;Yunchao Wei;Xiaodan Liang;Jian Dong;Tingfa Xu;Jiashi Feng;Shuicheng Yan;
Appeared in: IEEE Transactions on Multimedia
Publication date: May 2017, volume: 19, issue:5, pages: 944 - 954
Publisher: IEEE
 
» Attributed Scattering Center Extraction Algorithm Based on Sparse Representation With Dictionary Refinement
Abstract:
Compared with the point-scattering model, the attributed scattering center model (ASCM) is able to describe the frequency and aspect dependence of canonical scattering objects using solutions from both physical optics and the geometric theory of diffraction. As the ASCM is complicated, it may increase the dimension of the parameterized dictionary, which will increase the cost of computation and storage significantly. Aiming at this problem, a novel sparse representation-based algorithm, combined with an alternative optimization and dictionary refinement, is proposed. Utilizing the orthogonal matching pursuit algorithm combined with relaxation algorithm, the solution to the sparse signal recovery problem can be obtained. Numerical results on both electromagnetic computation data and measured SAR data verify the validity of the proposed algorithm.
Autors: Hongwei Liu;Bo Jiu;Fei Li;Yinghua Wang;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: May 2017, volume: 65, issue:5, pages: 2604 - 2614
Publisher: IEEE
 
» Attribution Mechanisms for Ancillary Service Costs Induced by Variability in Power Delivery
Abstract:
The increased penetration of renewable energy sources in existing power systems has led to necessary developments in electricity market mechanisms. Most importantly, renewable energy generation is increasingly made accountable for deviations between scheduled and actual energy generation. However, there is no mechanism to enforce accountability for the additional costs induced by power fluctuations. These costs are socialized and eventually supported by electricity customers. We propose some metrics for assessing the contribution of all market participants to power regulation needs, as well as an attribution mechanism for fairly redistributing related power regulation costs. We discuss the effect of various metrics used by the attribution mechanisms, and we illustrate, in a game-theoretical framework, their consequences on the strategic behavior of market participants. We also illustrate, by using the case of Western Denmark, how these mechanisms may affect revenues of the various market participants.
Autors: Francesca Bona;Nicolas Gast;Jean-Yves Le Boudec;Pierre Pinson;Dan-Cristian Tomozei;
Appeared in: IEEE Transactions on Power Systems
Publication date: May 2017, volume: 32, issue:3, pages: 1891 - 1901
Publisher: IEEE
 
» Auditory-Inspired Speech Envelope Extraction Methods for Improved EEG-Based Auditory Attention Detection in a Cocktail Party Scenario
Abstract:
This paper considers the auditory attention detection (AAD) paradigm, where the goal is to determine which of two simultaneous speakers a person is attending to. The paradigm relies on recordings of the listener’s brain activity, e.g., from electroencephalography (EEG). To perform AAD, decoded EEG signals are typically correlated with the temporal envelopes of the speech signals of the separate speakers. In this paper, we study how the inclusion of various degrees of auditory modelling in this speech envelope extraction process affects the AAD performance, where the best performance is found for an auditory-inspired linear filter bank followed by power law compression. These two modelling stages are computationally cheap, which is important for implementation in wearable devices, such as future neuro-steered auditory prostheses. We also introduce a more natural way to combine recordings (over trials and subjects) to train the decoder, which reduces the dependence of the algorithm on regularization parameters. Finally, we investigate the simultaneous design of the EEG decoder and the audio subband envelope recombination weights vector using either a norm-constrained least squares or a canonical correlation analysis, but conclude that this increases computational complexity without improving AAD performance.
Autors: Wouter Biesmans;Neetha Das;Tom Francart;Alexander Bertrand;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: May 2017, volume: 25, issue:5, pages: 402 - 412
Publisher: IEEE
 
» Auto-configurable optical amplifier for simple network operation and flexible access network design of a passive optical network
Abstract:
In this paper, we propose an auto-configurable optical amplifier (AC-OA) for passive optical networks (PONs); the value of optical attenuation is automatically controlled to prevent optical overloading of the OA. The AC-OA has a variable optical attenuator (VOA) at the input and a controller synchronized with an external facility database (FDB). The controller obtains the infrastructure information of each ONU and calculates the optimum setting for the input VOA. This structure enables the AC-OA to autonomously react to the spectrum being used. We simulate AC-OA operation based on the parameters of a commercial access network and evaluate the installation-cost reduction possible.
Autors: Takuya Tsutsumi;Yu Nakayama;Shunsuke Kanai;Manabu Kubota;Akihiro Otaka;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: May 2017, volume: 9, issue:5, pages: 446 - 455
Publisher: IEEE
 
» Autocalibrated Sampling Rate Conversion in the Frequency Domain [Tips & Tricks]
Abstract:
Frequency-domain sampling rate conversion (SRC) can be conveniently implemented by manipulating the discrete Fourier transform (DFT) of the input signal. This method has achieved the advantages of using less computation to obtain more accurate converted output. Conversion errors are mainly produced from the formulation process of the DFT of the output signal. This article presents a sparsity-based scheme to appropriately and automatically calibrate the conversion errors to make further improvement on the conversion accuracy at the cost of more computational complexity. The experimental results demonstrate that the proposed scheme can significantly decrease the meansquare errors (MSEs) and is particularly effective on minimizing the MSEs of phase spectrum.
Autors: Lifan Zhao;Xiumei Li;Lu Wang;Guoan Bi;
Appeared in: IEEE Signal Processing Magazine
Publication date: May 2017, volume: 34, issue:3, pages: 101 - 106
Publisher: IEEE
 
» Autofocusing and Polar Body Detection in Automated Cell Manipulation
Abstract:
Autofocusing and feature detection are two essential processes for performing automated biological cell manipulation tasks. In this paper, we have introduced a technique capable of focusing on a holding pipette and a mammalian cell under a bright-field microscope automatically, and a technique that can detect and track the presence and orientation of the polar body of an oocyte that is rotated at the tip of a micropipette. Both algorithms were evaluated by using mouse oocytes. Experimental results show that both algorithms achieve very high success rates: 100% and 96%. As robust and accurate image processing methods, they can be widely applied to perform various automated biological cell manipulations.
Autors: Zenan Wang;Chen Feng;Wei Tech Ang;Steven Yih Min Tan;Win Tun Latt;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: May 2017, volume: 64, issue:5, pages: 1099 - 1105
Publisher: IEEE
 
» Automated Assessment of Disease Progression in Acute Myeloid Leukemia by Probabilistic Analysis of Flow Cytometry Data
Abstract:
Objective: Flow cytometry (FC) is a widely acknowledged technology in diagnosis of acute myeloid leukemia (AML) and has been indispensable in determining progression of the disease. Although FC plays a key role as a posttherapy prognosticator and evaluator of therapeutic efficacy, the manual analysis of cytometry data is a barrier to optimization of reproducibility and objectivity. This study investigates the utility of our recently introduced nonparametric Bayesian framework in accurately predicting the direction of change in disease progression in AML patients using FC data. Methods: The highly flexible nonparametric Bayesian model based on the infinite mixture of infinite Gaussian mixtures is used for jointly modeling data from multiple FC samples to automatically identify functionally distinct cell populations and their local realizations. Phenotype vectors are obtained by characterizing each sample by the proportions of recovered cell populations, which are, in turn, used to predict the direction of change in disease progression for each patient. Results: We used 200 diseased and nondiseased immunophenotypic panels for training and tested the system with 36 additional AML cases collected at multiple time points. The proposed framework identified the change in direction of disease progression with accuracies of 90% (nine out of ten) for relapsing cases and 100% (26 out of 26) for the remaining cases. Conclusions: We believe that these promising results are an important first step toward the development of automated predictive systems for disease monitoring and continuous response evaluation. Significance: Automated measurement and monitoring of therapeutic response is critical not only for objective evaluation of disease status prognosis but also for timely assessment of treatment strategies.
Autors: Bartek Rajwa;Paul K. Wallace;Elizabeth A. Griffiths;Murat Dundar;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: May 2017, volume: 64, issue:5, pages: 1089 - 1098
Publisher: IEEE
 
» Automated Disease Identification With 3-D Optical Imaging: A Medical Diagnostic Tool
Abstract:
Digital holographic microscopy is an ideal tool for 3-D cell imaging and characterization. It provides a host of cell parameters based on cell morphology and its temporal dynamics or time variation. These parameters can be used to study and quantify cell growth and cell physiology. When coupled with classification algorithms, this technique can also be used to identify and classify cells such as blood cells for automated disease identification. A compact, portable version of this 3-D optical imaging system has the potential to become a device for compact field portable biological data collection, analysis, and cell identification leading to disease diagnosis with mobile devices, low cost instruments for deployment in remote areas with limited access to healthcare to combat disease. In this paper, we present an overview of our reported work on the development of digital holographic microscopes and their applications in 3-D cell imaging, cell parameter extraction and cell classification for potential automated disease identification.
Autors: Arun Anand;Inkyu Moon;Bahram Javidi;
Appeared in: Proceedings of the IEEE
Publication date: May 2017, volume: 105, issue:5, pages: 924 - 946
Publisher: IEEE
 
» Automatic Detection of 3D Quality Defects in Stereoscopic Videos Using Binocular Disparity
Abstract:
The 3D video quality issues that may disturb the human visual system and negatively impact the 3D viewing experience are well known and become more relevant as the availability of 3D video content increases, primarily through 3D cinema, but also through 3D television. In this paper, we propose four algorithms that exploit available stereo disparity information, in order to detect disturbing stereoscopic effects, namely, stereoscopic window violations, bent window effects, uncomfortable fusion object objects, and depth jump cuts on stereo videos. After detecting such issues, the proposed algorithms characterize them, based on the stress they cause to the viewer’s visual system. Qualitative representative examples, quantitative experimental results on a custom-made video data set, a parameter sensitivity study, and comments on the computational complexity of the algorithms are provided, in order to assess the accuracy and the performance of stereoscopic quality defect detection.
Autors: Sotirios Delis;Ioannis Mademlis;Nikos Nikolaidis;Ioannis Pitas;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: May 2017, volume: 27, issue:5, pages: 977 - 991
Publisher: IEEE
 
» Automatic Detection of Ship Targets Based on Wavelet Transform for HF Surface Wavelet Radar
Abstract:
High-frequency surface wave radar (HFSWR) has a vital civilian and military significance for continuous maritime surveillance of activities within exclusive economic zone. However, HFSWR has lower spatial and temporal resolutions and the received signals are strongly polluted by different clutter and background noise. Therefore, ship target detection by HFSWR has become a challenging task. This letter presents an automatic ship target detection algorithm based on discrete wavelet transform (DWT). First, a peak signal-to-noise ratio-based algorithm is proposed to automatically determine the optimal scale of DWT for extraction of ship targets. Second, the high-frequency coefficients of DWT at the optimal scale are processed by a fuzzy set-based method to enhance the useful target information and depress the unwanted background noises. Third, a target-highlighted image is reconstructed by ignoring all the low-frequency coefficients and performing inverse DWT only to the enhanced high-frequency coefficients. Finally, the targets are extracted by adaptive threshold segmentation of the final target-highlighted image. Experimental results show that the proposed approach can automatically extract ship targets effectively for range Doppler images with complex background, and has a better target detection performance than the previous wavelet-based algorithm, thereby providing a new reliable image processing-based method of ship target detection for HFSWR.
Autors: Qingzhong Li;Wandong Zhang;Ming Li;Jiong Niu;Q. M. Jonathan Wu;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 714 - 718
Publisher: IEEE
 
» Automatic Gauge Control under Laterally Asymmetric Rolling Conditions Combined with Feedforward
Abstract:
The most common and well proven control strategy for thickness control in industrial rolling mills is the automatic gauge controller (AGC). However, it is still unclear how to use AGC for the control of asymmetries in lateral direction. How should the controller react to different thickness estimations at both sides of the mill? Such laterally asymmetric rolling conditions may originate from strip track-off, asymmetric friction in the mill stand, or a wedge-shaped entry profile of the strip thickness. In this paper, three control approaches are discussed. Two different setups of AGC are compared and a feedforward (FF) approach is developed for lateral asymmetries of the entry thickness profile. Simulation studies based on a validated mill stand model demonstrate the benefit of combining AGC with a feedforward controller to compensate for asymmetries.
Autors: Katharina Prinz;Andreas Steinboeck;Martin Müller;Andreas Ettl;Andreas Kugi;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 2560 - 2568
Publisher: IEEE
 
» Automatic Reference Image Selection for Color Balancing in Remote Sensing Imagery Mosaic
Abstract:
Selection of a reference image is an important step in color balancing. However, the past research and currently available methods do not focus on it, leading to the lack of an effective way to select the reference image for color balancing in remote sensing imagery mosaic. This letter proposes a novel automatic reference image selection method that aims to select the reference images by assessing multifactors according to the land surface types of the target images. The proposed method addresses the limitations caused by the use of a single assessment factor as well as the selection of a single image as the reference in traditional methods. In addition, the proposed method has a wider range of applications than those requiring no reference image. The visual experimental results indicate that the proposed method can select the suitable reference images, which benefits the color balancing result, and outperforms the other comparative methods. Moreover, the absolute mean value of skewness metric of the proposed method is 0.0831, which is lower than the values of the other comparison methods. It indicates that the result of the proposed method had the best performance in the color information. The quantitative analyses with the metric of absolute difference of mean value indicate that the proposed method has a good ability in maintaining the spectral information, and the spectral changing rates had been reduced at least 10.66% by the proposed method when compared with the other methods.
Autors: Lei Yu;Yongjun Zhang;Mingwei Sun;Yihui Lu;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 729 - 733
Publisher: IEEE
 
» Automotive Software
Abstract:
This theme issue addresses automotive IT and software development. What technologies and principles deliver value, and how can you introduce them at a fast pace?
Autors: Christof Ebert;John Favaro;
Appeared in: IEEE Software
Publication date: May 2017, volume: 34, issue:3, pages: 33 - 39
Publisher: IEEE
 
» Autonomous System for Interpretation of Measurements Based on Adaptive Device
Abstract:
The monitoring and interpretation of electrical signals have been evolving nowadays. In this paper, an autonomous system based on the concepts of adaptivity has been developed with the goal to perform signal interpretation. The method consists in to receive signals acquired in the field through the sensors installed. From the processing carried out by the knowledge base deployed, the method is able to detect anomalies in the measured point and emits alarms or even actions to be accomplished by the engineer team. The experimental results validate the application of the adaptive method for monitoring and interpretation of signals.
Autors: Sidnei Nicoli;Jose Antonio Jardini;Romulo Goncalves Lins;
Appeared in: IEEE Latin America Transactions
Publication date: May 2017, volume: 15, issue:5, pages: 861 - 868
Publisher: IEEE
 
» AZO Thin Film Transistor Performance Enhancement by Capping an Aluminum Layer
Abstract:
Coplanar bottom-gate aluminum-zinc-oxide (AZO) thin film transistors (TFTs) with aluminum (Al) capping layers were fabricated in this work. The influences of the Al capping layer thickness and the post-annealing condition on the performance of the AZO-TFTswere investigated. Results show that the performance of the AZO-TFTs are enhanced significantly by introducing the Al capping layer on back channel, with saturation mobility increasing dramatically from 0.128 to 12.6 cm2/. The enhancement is ascribed to the diffusion of Al atoms into the AZO thin film and thus induced crystallization improvement.
Autors: Wen Yu;Dedong Han;Junchen Dong;Yingying Cong;Guodong Cui;Yi Wang;Shengdong Zhang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: May 2017, volume: 64, issue:5, pages: 2228 - 2232
Publisher: IEEE
 
» Bag-of-Discriminative-Words (BoDW) Representation via Topic Modeling
Abstract:
Many of the words in a given document either deliver facts (objective) or express opinions (subjective), respectively, depending on the topics they are involved in. For example, given a bunch of documents, the word “bug” assigned to the topic “order Hemiptera” apparently remarks one object (i.e., one kind of insects), while the same word assigned to the topic “software” probably conveys a negative opinion. Motivated by the intuitive assumption that different words have varying degrees of discriminative power in delivering the objective sense or the subjective sense with respect to their assigned topics, a model named as discriminatively objective-subjective LDA (dosLDA) is proposed in this paper. The essential idea underlying the proposed dosLDA is that a pair of objective and subjective selection variables are explicitly employed to encode the interplay between topics and discriminative power for the words in documents in a supervised manner. As a result, each document is appropriately represented as “bag-of-discriminativewords” (BoDW). The experiments reported on documents and images demonstrate that dosLDA not only performs competitively over traditional approaches in terms of topic modeling and document classification, but also has the ability to discern the discriminative power of each word in terms of its objective or subjective sense with respect to its assigned topic.
Autors: Yueting Zhuang;Hanqi Wang;Jun Xiao;Fei Wu;Yi Yang;Weiming Lu;Zhongfei Zhang;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: May 2017, volume: 29, issue:5, pages: 977 - 990
Publisher: IEEE
 
» Balancing Security and Usability in Encrypted Email
Abstract:
End-to-end encryption is the best way to protect digital messages. Historically, end-to-end encryption has been extremely difficult for people to use, but recent tools have made it more broadly accessible, largely by employing key-directory services. These services sacrifice some security properties for convenience. The authors wanted to understand how average users think about these tradeoffs. They conducted a 52-person user study and found that participants could learn to understand properties of different encryption models. Users also made coherent assessments about when different tradeoffs might be appropriate. Participants recognized that the less-convenient exchange model was more secure overall, but considered the registration model's security sufficient for most everyday purposes.
Autors: Wei Bai;Doowon Kim;Moses Namara;Yichen Qian;Patrick Gage Kelley;Michelle L. Mazurek;
Appeared in: IEEE Internet Computing
Publication date: May 2017, volume: 21, issue:3, pages: 30 - 38
Publisher: IEEE
 
» Baltic Sea Ice Concentration Estimation Using SENTINEL-1 SAR and AMSR2 Microwave Radiometer Data
Abstract:
Sea ice concentration (SIC) is an important sea ice parameter for sea ice navigation, environmental research, and weather and ice forecasting. We have developed and tested a method for estimation of the Baltic Sea SIC using SENTINEL-1 synthetic aperture radar (SAR) and Advanced Microwave Scanning Radiometer 2 passive microwave radiometer (MWR) data. Here, we present the method and results for January 2016. Ice concentration grids of Finnish Meteorological Institute daily ice charts have been used as reference data in this paper. We present a comparison of four SIC estimation methods with our reference data. In addition to the combined SAR/MWR SIC estimation method, we also compare SIC estimates produced using SAR alone and two MWR-based methods. The main target of this paper was to develop and test a high-resolution SIC estimation method suitable for operational use.
Autors: Juha Karvonen;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: May 2017, volume: 55, issue:5, pages: 2871 - 2883
Publisher: IEEE
 
» Band Assignment Approaches for Hyperspectral Sharpening
Abstract:
Classical pansharpening algorithms constitute a class of image fusion methods that have been widely investigated in the literature. They have been developed for combining a single- and a multichannel image (panchromatic (PAN) and multispectral (MS), respectively), but can be adapted to the sharpening of hyperspectral (HS) data, both through companion PAN and MS images. We focus in this letter on the HS/MS fusion, showing that the assignation of the MS channel to each HS band is a key step, and investigate several alternatives to make this choice. The assignment algorithms are tested in conjunction with both component substitution and multiresolution analysis pansharpening methods and assessed on images acquired by the Hyperion and ALI sensors. The numerical evaluation shows that the best results can be obtained by optimizing the spectral angle mapper metric confirming that classical methods represent a reliable basis for the development of novel sharpening algorithms.
Autors: Daniele Picone;Rocco Restaino;Gemine Vivone;Paolo Addesso;Mauro Dalla Mura;Jocelyn Chanussot;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 739 - 743
Publisher: IEEE
 
» Bathymetry Determination From Marine Radar Image Sequences Using the Hilbert Transform
Abstract:
This letter presents an image processing technique based on the theory of the Hilbert transform to determine the coastal bathymetry from marine radar image sequences. Use of the Hilbert transform enables the difficulties and complications of inhomogeneous image analysis to be avoided. In addition, a number of steps and complex computations can be avoided using the numerical algorithm of the Hilbert transform. Because the Hilbert transform is suitable for only monocomponent signals, we first applied the image procedure to decompose the irregular wave patterns into different single wave period images. Analysis of the simulated wave field and radar image sequences demonstrated that there was a high correlation between the estimated depths and reference depths. The causes for errors in the bathymetry estimations are also discussed.
Autors: Li-Chung Wu;Dong-Jiing Doong;Jong-Hao Wang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 644 - 648
Publisher: IEEE
 
» Bayesian Time-of-Flight for Realtime Shape, Illumination and Albedo
Abstract:
We propose a computational model for shape, illumination and albedo inference in a pulsed time-of-flight (TOF) camera. In contrast to TOF cameras based on phase modulation, our camera enables general exposure profiles. This results in added flexibility and requires novel computational approaches. To address this challenge we propose a generative probabilistic model that accurately relates latent imaging conditions to observed camera responses. While principled, realtime inference in the model turns out to be infeasible, and we propose to employ efficient non-parametric regression trees to approximate the model outputs. As a result we are able to provide, for each pixel, at video frame rate, estimates and uncertainty for depth, effective albedo, and ambient light intensity. These results we present are state-of-the-art in depth imaging. The flexibility of our approach allows us to easily enrich our generative model. We demonstrate this by extending the original single-path model to a two-path model, capable of describing some multipath effects. The new model is seamlessly integrated in the system at no additional computational cost. Our work also addresses the important question of optimal exposure design in pulsed TOF systems. Finally, for benchmark purposes and to obtain realistic empirical priors of multipath and insights into this phenomena, we propose a physically accurate simulation of multipath phenomena.
Autors: Amit Adam;Christoph Dann;Omer Yair;Shai Mazor;Sebastian Nowozin;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: May 2017, volume: 39, issue:5, pages: 851 - 864
Publisher: IEEE
 
» Beehive: Erasure Codes for Fixing Multiple Failures in Distributed Storage Systems
Abstract:
In distributed storage systems, erasure codes have been increasingly deployed to tolerate server failures without loss of data. Traditional erasure codes, such as Reed-Solomon codes, suffer from a high volume of network transfer and disk I/O to recover unavailable data at failed storage servers. Typically, unavailable data at different failed storage servers in a distributed storage system are fixed separately. It has been shown that it is possible to reduce the volume of network transfer significantly by reconstructing data from multiple storage servers at the same time. However, there has been no construction of erasure codes to achieve it without imposing strict constraints on system parameters. In this paper, we propose Beehive codes, designed for optimizing the volume of network transfers to fix the data on multiple failed storage servers. Beehive codes can be constructed over a wide range of system parameters at code rate no more than 0.5, while incurring slightly more storage overhead than Reed-Solomon codes. To achieve the optimal storage overhead as Reed-Solomon codes, we further extend vanilla Beehive codes to MDS Beehive codes, which incurs near-optimal volumes of network transfers during reconstruction. We implement both Beehive and MDS Beehive Codes in C++ and evaluate their performance on Amazon EC2. Our evaluation results have clearly shown that the volume of both network transfers and disk I/O can be conserved by a substantial margin.
Autors: Jun Li;Baochun Li;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: May 2017, volume: 28, issue:5, pages: 1257 - 1270
Publisher: IEEE
 
» Being a Supercook: Joint Food Attributes and Multimodal Content Modeling for Recipe Retrieval and Exploration
Abstract:
This paper considers the problem of recipe-oriented image-ingredient correlation learning with multi-attributes for recipe retrieval and exploration. Existing methods mainly focus on food visual information for recognition while we model visual information, textual content (e.g., ingredients), and attributes (e.g., cuisine and course) together to solve extended recipe-oriented problems, such as multimodal cuisine classification and attribute-enhanced food image retrieval. As a solution, we propose a multimodal multitask deep belief network (TDBN) to learn joint image-ingredient representation regularized by different attributes. By grouping ingredients into visible ingredients (which are visible in the food image, e.g., “chicken” and “mushroom”) and nonvisible ingredients (e.g., “salt” and “oil”), TDBN is capable of learning both midlevel visual representation between images and visible ingredients and nonvisual representation. Furthermore, in order to utilize different attributes to improve the intermodality correlation, TDBN incorporates multitask learning to make different attributes collaborate each other. Based on the proposed TDBN, we exploit the derived deep features and the discovered correlations for three extended novel applications: 1) multimodal cuisine classification; 2) attribute-augmented cross-modal recipe image retrieval; and 3) ingredient and attribute inference from food images. The proposed approach is evaluated on the construct- d Yummly dataset and the evaluation results have validated the effectiveness of the proposed approach.
Autors: Weiqing Min;Shuqiang Jiang;Jitao Sang;Huayang Wang;Xinda Liu;Luis Herranz;
Appeared in: IEEE Transactions on Multimedia
Publication date: May 2017, volume: 19, issue:5, pages: 1100 - 1113
Publisher: IEEE
 
» Benefit Points: The Best Part of the Story
Abstract:
Delivering valuable software to your customer is the first priority in agile management and development. The product owner is involved along the way, and backlogs are prioritized, with the best of intentions to maximize business value early and eliminate waste. Yet in many IT development projects, bewilderment remains as to how to express business value in process decisions and the delivered system. Also, projects continue to implement functionality that's off the mark or never used. This situation occurs because there isn't sufficient methodological support to determine and monitor business value or to link business value decisions to the development project's mechanics. However, researchers have developed a bundle of easy-to-use core practices that help systematize a project's evolving knowledge. Although these practices are simple, they provide powerful support for monitoring project progress on both the realized business value and the realized costs.
Autors: Jo Erskine Hannay;Hans Christian Benestad;Kjetil Strand;
Appeared in: IEEE Software
Publication date: May 2017, volume: 34, issue:3, pages: 73 - 85
Publisher: IEEE
 
» Bespoke Lenses Based on Quasi-Conformal Transformation Optics Technique
Abstract:
In this paper, a systematic method to design a quasi-optimum lens profile based on quasi-conformal transformation optics technique for a given excitation is presented. This method is applied to a number of conventional antennas, such as an aperture and a log-spiral slot. In all these configurations, an increase of the directivity is observed. Furthermore, using this method, a quasi-optimum graded index lens for a broadband enhanced leaky slot excitation is designed and the results are compared with a hyperhemispherical lens with and without matching layers. Our proposed methodology demonstrates to be able to increase the directivity, to reduce the sidelobes and the cross polarization in a broad bandwidth from 20 to 70 GHz. Due to the continuously changed dielectric constant of the lens profile, reflections are also reduced considerably inside the lens.
Autors: Mahsa Ebrahimpouri;Oscar Quevedo-Teruel;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: May 2017, volume: 65, issue:5, pages: 2256 - 2264
Publisher: IEEE
 
» Better Now Than Later: Managing Technical Debt in Systems Development
Abstract:
Technical debt is incurred when development project tasks are deferred either unintentionally or deliberately. Detecting and mitigating this debt, including controlling it through risk management techniques, can help avoid or address common project pitfalls, such as late delivery, team burnout, and cost overruns.
Autors: Richard E. Fairley;Mary Jane Willshire;
Appeared in: Computer
Publication date: May 2017, volume: 50, issue:5, pages: 80 - 87
Publisher: IEEE
 
» Blind Estimation of the HPA Operating Point in Multicarrier Satellite Transponders
Abstract:
Satellite operators need to know the operating point of a transponder to provide a good transmission quality. Especially in satellite networks with many small carriers in one transponder, the estimation is challenging because of gain compression, capture effects or unknown attenuation in the transmission channel. We propose a blind estimator based on signal statistics to overcome these problems. The new estimator is independent of a-priori information about the carrier modulation and the absolute power of the received signal. The method is applicable to existing satellites because we only use a simulation model of the transponder together with the sampled receive signal for the estimation process.
Autors: Matthias G. Schraml;Andreas Knopp;
Appeared in: IEEE Communications Letters
Publication date: May 2017, volume: 21, issue:5, pages: 1051 - 1054
Publisher: IEEE
 
» Blind Interference Alignment for Multiuser MISO Indoor Visible Light Communications
Abstract:
A filter-pair-based blind interference alignment scheme is proposed to improve the achievable degree of freedom (DoF) in multiuser multiple-input single-output indoor visible light communications. In the proposed scheme, the transmitter does not need to know channel state information. Different transmit sub-channels employ different pulse-shaping filters, and each user is equipped with multiple receive filters. The transmitter sends signals according to the predesigned strategy, and each user sets the receive mode by choosing the corresponding receive filter. Optical orthogonal frequency division multiplexing is employed in the proposed scheme to combat the intersymbol interference in high-speed transmissions, and the maximum achievable spectrum efficiency (SE) of the proposed scheme is analyzed. Simulation results validate that the proposed scheme can achieve higher SE and more DoF than the orthogonal multiple access schemes.
Autors: Liang Wu;Zaichen Zhang;Jian Dang;Huaping Liu;
Appeared in: IEEE Communications Letters
Publication date: May 2017, volume: 21, issue:5, pages: 1039 - 1042
Publisher: IEEE
 
» Blind Sharpness Prediction for Ultrahigh-Definition Video Based on Human Visual Resolution
Abstract:
We explore a no-reference sharpness assessment model for predicting the perceptual sharpness of ultrahigh-definition (UHD) videos through analysis of visual resolution variation in terms of viewing geometry and scene characteristics. The quality and sharpness of UHD videos are influenced by viewer perception of the spatial resolution afforded by the UHD display, which depends on viewing geometry parameters including display resolution, display size, and viewing distance. In addition, viewers may perceive different degrees of quality and sharpness according to the statistical behavior of the visual signals, such as the motion, texture, and edge, which vary over both spatial and temporal domains. The model also accounts for the resolution variation associated with fixation and foveal regions, which is another important factor affecting the sharpness prediction of UHD video over the spatial domain and which is caused by the nonuniform distribution of the photoreceptors. We calculate the transition of the visually salient statistical characteristics resulting from changing the display’s screen size and resolution. Moreover, we calculated the temporal variation in sharpness over consecutive frames in order to evaluate the temporal sharpness perception of UHD video. We verify that the proposed model outperforms other sharpness models in both spatial and temporal sharpness assessments.
Autors: Haksub Kim;Jongyoo Kim;Taegeun Oh;Sanghoon Lee;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: May 2017, volume: 27, issue:5, pages: 951 - 964
Publisher: IEEE
 
» Block-Matching Distortion Correction of Echo-Planar Images With Opposite Phase Encoding Directions
Abstract:
By shortening the acquisition time of MRI, Echo Planar Imaging (EPI) enables the acquisition of a large number of images in a short time, compatible with clinical constraints as required for diffusion or functional MRI. However such images are subject to large, local distortions disrupting their correspondence with the underlying anatomy. The correction of those distortions is an open problem, especially in regions where large deformations occur. We propose a new block-matching registration method to perform EPI distortion correction based on the acquisition of two EPI with opposite phase encoding directions (PED). It relies on new transformations between blocks adapted to the EPI distortion model, and on an adapted optimization scheme to ensure an opposite symmetric transformation. We present qualitative and quantitative results of the block-matching correction using different metrics on a phantom dataset and on in-vivo data. We show the ability of the block-matching to robustly correct EPI distortion even in strongly affected areas.
Autors: Renaud Hédouin;Olivier Commowick;Elise Bannier;Benoit Scherrer;Maxime Taquet;Simon K. Warfield;Christian Barillot;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: May 2017, volume: 36, issue:5, pages: 1106 - 1115
Publisher: IEEE
 
» BlockPy: An Open Access Data-Science Environment for Introductory Programmers
Abstract:
Non-computer science majors often struggle to find relevance in traditional computing curricula that tend to emphasize abstract concepts, focus on nonpractical entertainment, or rely on decontextualized settings. BlockPy, a web-based, open access Python programming environment, supports introductory programmers in a data-science context through a dual block/text programming view. The web extra at https://youtu.be/RzaOPqOpMoM illustrates BlockPy features discussed in the article.
Autors: Austin Cory Bart;Javier Tibau;Eli Tilevich;Clifford A. Shaffer;Dennis Kafura;
Appeared in: Computer
Publication date: May 2017, volume: 50, issue:5, pages: 18 - 26
Publisher: IEEE
 
» Book Reviews [7 Books Reviewed]
Abstract:
Books reviewed are: Photovoltaic Laboratory-Safety, Code-Compliance,and Commercial Off-the-Shelf Equipment, by P. T. Parrish, CRC Press Taylor & Francis Group; Dielectrics in Electric Fields,2nd Edition by, G. G. Raju CRC Press Taylor & Francis Group; Advanced Piezoelectric Materials-Science and Technology by K. Uchino, editor Woodhead Publishing; Introduction to Modern Power Electronics, 3rd Edition, by A. M. Trzynadlowski John Wiley & Sons Inc.; Engineering Electrodynamics, by J. Turowski and M. Turowski CRC Press Taylor & Francis Group; Discharge in Long Air Gaps-Modeling and Applications, by A. Beroual and I. Fofana IOP Publishing; Impedance Source Power Electronic Converters by Y. Liu, H. Abu-Rub, F. Blaabjerg, O.Ellabban, and P. C. Loh, John Wiley & Sons Inc.
Autors: John J. Shea;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: May 2017, volume: 33, issue:3, pages: 42 - 47
Publisher: IEEE
 
» Breezing My Way as a Solution Architect: A Retrospective on Skill Development and Use
Abstract:
Solution architecture is a team effort balancing various forces. Solution architects must consciously cultivate skills cutting across technical, social, and behavioral domains. In this article, Raghuraman Krishnamurthy discusses eight such skills that will likely be helpful.
Autors: Raghuraman Krishnamurthy;
Appeared in: IEEE Software
Publication date: May 2017, volume: 34, issue:3, pages: 9 - 13
Publisher: IEEE
 
» Brevity, Clarity, Engagement: The IMS2017 Three Minute Thesis Competition
Abstract:
Presents information on the IMS 2017 Conference.
Autors: John W. Bandler;Erin M. Kiley;
Appeared in: IEEE Microwave Magazine
Publication date: May 2017, volume: 18, issue:3, pages: 85 - 87
Publisher: IEEE
 
» Broadband Analog Network Coding With Robust Processing for Two-Way Relay Networks
Abstract:
In this letter, we study the robust processing for a single carrier two-way relay network with broadband analog network coding and imperfect channel state information. Based on a statistical model for channel estimation error, we derive the optimal coefficients of self interference cancellation and linear frequency domain equalization in the sense of minimizing the conditional mean square error given a channel estimate. Simulation results show that the proposed robust design can achieve better bit error rate performance than the conventional non-robust scheme.
Autors: Jiejun Qin;Yu Zhu;Pengfei Zhe;
Appeared in: IEEE Communications Letters
Publication date: May 2017, volume: 21, issue:5, pages: 1115 - 1118
Publisher: IEEE
 
» Broadband and Wavelength-Dependent Chalcogenide Optical Fiber Couplers
Abstract:
We present optical fiber couplers made of As2Se3 glass. Broadband and wavelength-dependent couplers are fabricated from fibers of engineered core/cladding diameter ratios. Coupling ratios at the through-cross ports ranging from 50%–50% down to 1%–99% are achieved. The transparency of As2Se3 glass over the spectral range of 1.5–12.0 makes it a material of prime interest for the fabrication of mid-infrared couplers.
Autors: Farzan Tavakoli;Alexandre Rekik;Martin Rochette;
Appeared in: IEEE Photonics Technology Letters
Publication date: May 2017, volume: 29, issue:9, pages: 735 - 738
Publisher: IEEE
 
» Broadband CMOS Schottky-Diode Star Mixer Using Coupled-CPW Marchand Dual-Baluns
Abstract:
A broadband CMOS Marchand dual-balun using stacked broadside couplers for low odd-mode impedance with surrounded ground planes for high even-mode impedance is employed to achieve a high coupling coefficient needed for a Marchand dual-balun. The demonstrated Marchand dual-balun using 0.18- CMOS technology is designed at 30-GHz center frequency with an insertion loss of 11.5- and 10-dB input return loss bandwidth of over 120%. The bandwidth of 1-dB amplitude imbalance and 10° phase difference are over 100%. A broadband CMOS Schottky-diode star mixer is implemented with two Marchand dual-baluns at RF and local oscillator (LO) ports. As a result, the Schottky-diode star mixer shows conversion loss of 14 dB, LO-to-RF isolation of 26 dB, LO-to-IF isolation of 45 dB, and RF-to-IF isolation of 42 dB within 27-GHz operating bandwidth, respectively.
Autors: Yu-Chih Hsiao;Chinchun Meng;Yong-Hao Peng;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: May 2017, volume: 27, issue:5, pages: 500 - 502
Publisher: IEEE
 
» Broadband Dual-Port Intermodulation Generator for Passive Intermodulation Measurements
Abstract:
A dual-port tunable intermodulation (IM) generator is reported. This IM generator employs a coupling network to distribute carrier waves and IM. The proposed coupling network is constructed by cascading four parallel-coupled directional couplers, while a Schottky diode is working as a tunable IM source. By adjusting the IM performance of diode using bias voltage and distributing IM along symmetrical IM paths, a pair of tunable IM signals is introduced into passive IM (PIM) test loop simultaneously, they can serve as bidirectional IM reference in dual-port PIM measurements. The provided IM3 can be tuned to be lower than −112 dBm at dBm at either 710 or 2550 MHz, while their dynamic IM3 range can reach about 20 dB at dBm. The work promotes the application of IM predistortion techniques and provides a solution to realize dual-port dynamic IM calibration in PIM test.
Autors: Xiong Chen;Yongning He;Wanzhao Cui;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: May 2017, volume: 27, issue:5, pages: 518 - 520
Publisher: IEEE
 
» Broadband Microwave Signal Processing Based on Photonic Dispersive Delay Lines
Abstract:
The development of communications technologies has led to an ever-increasing demand for a higher speed and wider bandwidth of microwave signal processors. To overcome the inherent electronic speed limitations, photonic techniques have been developed for processing of ultrabroadband microwave signals. A dispersive delay line (DDL) is a key photonic device that can be used to implement signal processing functions, such as time reversal, time delay, dispersion compensation, Fourier transformation, and pulse compression. Compared with an electrical delay line, a photonic DDL has a much wider bandwidth and can be used for processing a microwave signal with a much wider bandwidth. In this paper, we review our recent work using photonic DDLs for processing of broadband microwave signals. Two types of DDLs are to be discussed, a linearly chirped fiber Bragg grating-based DDL and an optical dispersive loop-based DDL. Signal processing functions including microwave time reversal, microwave temporal convolution, time-stretched sampling, microwave waveform generation with an extended temporal duration, and wideband true-time delay beamforming are discussed.
Autors: Jiejun Zhang;Jianping Yao;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: May 2017, volume: 65, issue:5, pages: 1891 - 1903
Publisher: IEEE
 
» Broadcast Erasure Channel With Feedback and Message Side Information, and Related Index Coding Result
Abstract:
We consider the -receiver broadcast erasure channel with feedback and message side information at the receivers prior to beginning of transmission. Specifically, the transmitter must deliver different, independent messages to each of the receivers, and each receiver knows a function of these messages before transmission begins. This situation can arise in multi-hop wireless networks, where a receiver may overhear transmissions consisting of possibly encoded combinations of messages (e.g., encoded using a network coding technique) prior to beginning of transmission over a given broadcast channel. We provide an outer bound to the capacity region of this system. For the case, where each message consists of a number of symbols taking values in a finite field and each receiver knows linear combinations of these symbols, the outer bound is given in terms of ranks of matrices expressing the linear combinations. For the latter case and when , the outer bound is tight under mild conditions on the limiting behavior of the ranks of matrices expressing the side information. We provide a capacity achieving code for this case. The special case, where each receiver either knows the entire message of another receiver or has no information about it, constitutes a generalization of the index coding problem that incorporates channel erasures. For this instance, and when there are no channel errors, we show that the outer bound reduces to the known maximum weighted acyclic induced subgraph bound.
Autors: Athanasios Papadopoulos;Leonidas Georgiadis;
Appeared in: IEEE Transactions on Information Theory
Publication date: May 2017, volume: 63, issue:5, pages: 3161 - 3180
Publisher: IEEE
 
» Buckle Up: The Smart Grid Rollout Begins [In My View]
Abstract:
A valuable set of matured smart grid concepts has emerged from the significant trial-and-demonstration programs around the world. An investment in rollout programs is now required to deliver the full value of these initial investments to electricity customers. Managing the risks and making an effective transition to the smarter grid are significant challenges but a growing body of experience, strong principles, and effective solutions to the issues are helping to make smart grids business as usual. Innovative grid solutions trials create real operating environments for assessing the technical and commercial performance of solutions to industry problems. They also enhance basic technological understanding, leading to improved design and production quality of rollout-ready solutions.
Autors: Graham Ault;
Appeared in: IEEE Power and Energy Magazine
Publication date: May 2017, volume: 15, issue:3, pages: 104 - 100
Publisher: IEEE
 
» Build your own Amazon Echo - Turn a PI into a voice controlled gadget [Resources_Hands on]
Abstract:
As a young man, I yearned for a machine like the ship's computer on Star Trek: a gadget that can listen and obey a human voice, and answer in kind. Fifteen years ago, after reading about university researchers who had gotten voice-controlled artificial intelligence systems working, I taught myself Linux and set up a server in my attic in the hope that the technology had arrived to let me build such a thing myself. It had not.
Autors: W. Wayt Gibbs;
Appeared in: IEEE Spectrum
Publication date: May 2017, volume: 54, issue:5, pages: 20 - 21
Publisher: IEEE
 

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