Electrical and Electronics Engineering publications abstract of: 01-2017 sorted by title, page: 9

» Impact of Directionality on Interference Mitigation in Full-Duplex Cellular Networks
Abstract:
In this paper, we consider two fundamental full-duplex (FD) architectures, two-node and three-node, in the context of cellular networks where the terminals employ directional antennas. The simultaneous transmission and reception of data in non-orthogonal channels makes FD radio a potential solution for the currently limited spectrum. However, its implementation generates high levels of interference either in the form of loopback interference (LI) from the output to the input antenna of a transceiver or in the form of co-channel interference in large-scale multicell networks due to the large number of active links. Using a stochastic geometry model, we investigate how directional antennas can control and mitigate the co-channel interference. Furthermore, we provide a model which characterizes the way directional antennas manage the LI in order to passively suppress it. Our results show that both architectures can benefit significantly by the employment of directional antennas. Finally, we consider the case where both architectures are employed in the network and derive the optimal values for the density fraction of each architecture, which maximize the success probability and the network throughput.
Autors: Constantinos Psomas;Mohammadali Mohammadi;Ioannis Krikidis;Himal A. Suraweera;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 487 - 502
Publisher: IEEE
 
» Impact of Fin Height and Fin Angle Variation on the Performance Matrix of Hybrid FinFETs
Abstract:
In this paper, we systematically examined the impact of fin height () and fin angle () on the ac performance parameters including total gate capacitance (), delay (), cutoff frequency (), energy (), total power (), and leakage power () of hybrid FinFETs at the supply voltage, with on-current . The delay, energy, and total power consumption are the primary factors limiting the operating frequency of the high-performance devices. Therefore, these electrical parameters are needed to be addressed in the architectural level of the fin based devices. In this paper, a calibrated numerical device simulation tool is used to achieve the best device performances of 14-nm hybrid FinFETs. From the simulated current–voltage (–) and capacitance–voltage (–) characteristics of hybrid FinFETs, the parameters , , , CV2, , and are extracted to analyze the effect of and on the performance matrices of these devices. In addition, this paper proposes an optimum structural configuration for 14-nm hybrid FinFET architecture for digital application perspective.
Autors: Kumar Prasannajit Pradhan;Samar K. Saha;Prasanna Kumar Sahu; Priyanka;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 52 - 57
Publisher: IEEE
 
» Impact of Full Duplex Scheduling on End-to-End Throughput in Multi-Hop Wireless Networks
Abstract:
There have been some rapid advances on the design of full duplex (FD) transceivers in recent years. Although the benefits of FD have been studied for single-hop wireless communications, its potential on throughput performance in a multi-hop wireless network remains unclear. As for multi-hop networks, a fundamental problem is to compute the achievable end-to-end throughput for one or multiple communication sessions. The goal of this paper is to offer some fundamental understanding on end-to-end throughput performance limits of FD in a multi-hop wireless network. We show that through a rigorous mathematical formulation, we can cast the multi-hop throughput performance problem into a formal optimization problem. Through numerical results, we show that in many cases, the end-to-end session throughput in a FD network can exceed of that in a half duplex (HD) network. Our finding can be explained by the much larger design space for scheduling that is offered by removing HD constraints in throughput maximization problem. The results in this paper offer some new understandings on the potential benefits of FD for end-to-end session throughput in a multi-hop wireless network.
Autors: Xiaoqi Qin;Huacheng Zeng;Xu Yuan;Brian Jalaian;Y. Thomas Hou;Wenjing Lou;Scott F. Midkiff;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 158 - 171
Publisher: IEEE
 
» Impact of Next-Generation Mobile Technologies on IoT-Cloud Convergence
Abstract:
Autors: M. Shamim Hossain;Changsheng Xu;Ying Li;Al-Sakib Khan Pathan;Josu Bilbao;Wenjun Zeng;Abdulmotaleb El Saddik;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2017, volume: 55, issue:1, pages: 18 - 19
Publisher: IEEE
 
» Impact of Parasitic Capacitance and Ferroelectric Parameters on Negative Capacitance FinFET Characteristics
Abstract:
In this letter, we present a compact model and analyze the impact of key parameters on negative capacitance FinFET (NC-FinFET) device operation. The developed model solves FinFET device electrostatics and Landau–Khalatnikov equations self-consistently. An experimental NC-FinFET device is accurately modeled and the experimentally calibrated parameters are used to analyze the NC-FinFETs device performance and its dependence on several key parameters.
Autors: Sourabh Khandelwal;Juan Pablo Duarte;Asif Islam Khan;Sayeef Salahuddin;Chenming Hu;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2017, volume: 38, issue:1, pages: 142 - 144
Publisher: IEEE
 
» Impact of Using Resistive Elements for Wideband Isolation Improvement
Abstract:
Improving the isolation between antenna elements in compact arrays has been a major focus of recent research. In this paper, we present ideas to improve the wideband isolation between closely spaced antennas. We do this by connecting lumped lossy (resistive) elements between the antenna feeds. A simple analytical expression is provided to compute the impact of resistive elements on efficiency to analyze the power lost in the resistive element. Three configurations of decoupling circuits are designed and fabricated for two closely spaced monopoles operating at 2.4 GHz. The decoupling circuit contains transmission lines of different lengths at the antenna inputs such that the mutual admittance between the antenna elements is: 1) resistive; 2) resistive and inductive; or 3) resistive and capacitive. Lumped elements are then connected between the transmission lines followed by matching circuit. This paper shows that with configurations 2) and 3), we can improve the wideband isolation compared with 1), as well as compared with using only lossless elements. The wideband isolation was improved by 17.6 dB across a 200-MHz band at 2.4 GHz, with a final isolation level of 20 dB over that band. Better than 30 dB isolation was achieved across a narrower band of 55 MHz. The proposed technique provides wideband isolation improvement for multiple-input multiple-output as well as narrowband performance with large isolation suitable for in-band full-duplex applications. The impact on efficiency is investigated to verify that the advantages from the improved wideband isolation outweigh the possible reduction in overall efficiency.
Autors: Sathya N. Venkatasubramanian;Linsheng Li;Anu Lehtovuori;Clemens Icheln;Katsuyuki Haneda;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2017, volume: 65, issue:1, pages: 52 - 62
Publisher: IEEE
 
» Impacts of Reduced Motor Cooling on Reliability
Abstract:
It has been well documented that bearing failures are the leading cause for grease lubricated motor repairs, and grease service life deterioration is a leading cause of bearing failures. Grease service life deteriorates rapidly with elevated operating temperatures, so it may be ascertained that a design change significantly reducing motor cooling would result in elevated bearing temperature, marginal lubrication, premature bearing failures, and reduced motor reliability. In recent years, the ever increasing drive for higher motor efficiencies has resulted in motor designs with less cooling capacity. A recent refinery motor reliability study confirms this correlation and highlights the issue with inadequately cooled motors. Results of the study reveal why new IEEE Standard 841 high-efficiency motors are at greater risk of a drive end bearing failure than the older motors they are replacing. The current IEEE Standard 841 allowable bearing temperature rise is exceedingly high (50 °C/90 °F rise on two-pole motors). To optimize bearing service life and motor reliability, this allowable temperature rise should be reduced significantly.
Autors: Ralph Gerstenkorn;Tyler Somes;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 739 - 744
Publisher: IEEE
 
» Impedance Spectroscopic Analysis of the InSe/ZnSe/InSe Interface
Abstract:
In this paper, n-InSe/p-ZnSe/n-InSe (npn) thin-film transistors (TFTs) are deposited onto cubic (111)-oriented Ag, Au, and Al thin-film substrates. The properties of the structures are explored by means of X-ray diffraction and impedance spectroscopy in the frequency range of 10–1800 MHz. Although the Ag, Au, and Al substrates are observed to be well aligned with the cubic ZnSe, the electrical properties of these TFT for the np (InSe/ZnSe) and npn interfaces are different. Namely, while the capacitance of the TFT deposited onto the Ag substrate exhibited positive values, the capacitance of the TFT deposited onto Au and Al films is negative in the range of 10–1100 and 800–1800 MHz, respectively. In addition, even though the impedance of the Ag/np/Ag and Ag/npn/Ag heterojunction monotonically decreased with the increasing frequency, the impedance of Au/np/Au and Au/npn/Au interfaces exhibited resonance peaks at 1211 and 1148 MHz, respectively. When the wave trap features are read from reflection spectra, it is observed that the Ag/npn/Ag and the Al/np/Ag exhibit low-pass filter properties and the Au/npn/Au behaves as a bandstop filter at a notch frequency of 1176 MHz. These properties nominate the npn transistors for use as microwave traps and as high-speed CMOS amplifiers.
Autors: Sabah E. Al Garni;Atef F. Qasrawi;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 244 - 249
Publisher: IEEE
 
» Implantable Microimaging Device for Observing Brain Activities of Rodents
Abstract:
In this review, we present an implantable microimaging device to observe brain activities of small experimental animals such as mice and rats. Three categories of such devices are described: an optical fiber system, a head-mountable fluorescent microscope, and an ultrasmall image sensor that can be directly implanted into the brain. Among them, we focus on the third one, because this is a powerful tool to explore brain activities in deep brain region in a freely moving mouse. The device structure and performance are shown with some examples of deep brain images of mice.
Autors: Jun Ohta;Yasumi Ohta;Hiroaki Takehara;Toshihiko Noda;Kiyotaka Sasagawa;Takashi Tokuda;Makito Haruta;Takuma Kobayashi;Yasemin M. Akay;Metin Akay;
Appeared in: Proceedings of the IEEE
Publication date: Jan 2017, volume: 105, issue:1, pages: 158 - 166
Publisher: IEEE
 
» Implementation and Switching Behavior of a PCB-DBC IGBT Module Based on the Power Chip-on-Chip 3-D Concept
Abstract:
With the emergence of new power semiconductor devices, the switching speeds in power converters are increasing. The stray inductances of switching cells must, therefore, be minimized to limit overvoltages on transistors. One relatively new approach, called power chip-on-chip (PCoC), considers the integration of power dies, one on top of the other, directly in the busbar. This allows for the reduction of the stray inductance. This paper first presents the implementation of a PCoC module using classical packaging techniques. Then, a description of the different technological steps for the realization is outlined. Finally, experimental characterization results confirm the lower stray inductances offered by the PCoC package compared with the planar one.
Autors: Jean-Louis Marchesini;Pierre-Olivier Jeannin;Yvan Avenas;Johan Delaine;Cyril Buttay;Raphaël Riva;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 362 - 370
Publisher: IEEE
 
» Implementation of NG9-1-1 in Rural America–The Counties of Southern Illinois: Experience and Opportunities
Abstract:
This article describes the deployment of a next generation 9-1-1 network in Southern Illinois. Thirteen counties and one municipality banded together to design, build, test and deploy this network, which provides voice, text, video and data services to emergency callers, call takers, and first responders. The author describes key challenges where contributions have been and will continue to be made through the collaboration of industry, academia, government, and standards bodies. Lessons learned and potential next steps are examined.
Autors: Barbara Kemp;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2017, volume: 55, issue:1, pages: 152 - 158
Publisher: IEEE
 
» Improved dynamic bandwidth allocation algorithm forXGPON
Abstract:
Passive optical networks (PONs) require a dynamic bandwidth allocation (DBA) algorithm at the optical line terminal for efficient utilizationofupstreambandwidth among the optical network units (ONUs) as per the quality of service requirements for each traffic class defined by PON standardizing bodies. The GigaPON access network (GIANT) was the first International Telecommunication Union compliant DBAalgorithm, which is further improved by Immediate Allocation with Colorless Grant (IACG) and Efficient Bandwidth Utilization (EBU) algorithms. However, the polling mechanism of IACG and EBU may not report the true bandwidthdemandofONUsduring a service interval. Furthermore, ONU scheduling mechanisms give preference to best effort traffic over the assured traffic during recursive allocation cycles in a service interval, which results in an increase in upstream delays for the assured traffic class. This paper presents an improved bandwidth utilization (IBU) algorithm, which rectifies these deficiencies with a novel polling and scheduling mechanism. Experimental results show that IBU improves the mean of upstream delays of type 2 traffic up to 98%, 93%, and 76% and up to 99%, 92%, and 73% for type 3 traffic compared to the GIANT, IACG, and EBU algorithms, respectively. IBU also shows the least frame loss compared to these state-of-the-art algorithms.
Autors: Rizwan Aslam Butt;Sevia Mahdaliza Idrus;Kashif Naseer Qureshi;Nadiatulhuda Zulkifli;Siti Hasunah Mohammad;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Jan 2017, volume: 9, issue:1, pages: 87 - 97
Publisher: IEEE
 
» Improved Power Quality Bridgeless Converter-Based SMPS for Arc Welding
Abstract:
This paper proposes a power-factor-corrected bridgeless (BL) switched-mode power supply (SMPS) for welding applications that possesses output voltage control and current limiting feature even during extreme overloading conditions at the output terminals. Eliminating an input diode bridge rectifier minimizes conduction losses and improves thermal utilization of semiconductor devices. The front-end of the proposed SMPS consists of a BL boost converter operating in a continuous conduction mode to attain unity power factor, while at the rear end a pulse width modulation isolated full bridge dc–dc converter is used to regulate the output voltage. The design and implementation of this BL arc welding power supply (AWPS) is presented showing its fast dynamic response to supply voltage and load variations. The performance of the proposed AWPS is examined in terms of power factor, total harmonic distortion of the supply current, efficiency, and output current limit over a wide range of line/load variations. Test results confirm the effectiveness of the proposed AWPS in maintaining an impeccable power quality at utility interface apart from achieving an excellent output voltage regulation and current limiting capability.
Autors: Swati Narula;Bhim Singh;G. Bhuvaneswari;Rahul Pandey;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 275 - 284
Publisher: IEEE
 
» Improved Realtime State-of-Charge Estimation of LiFePO $_{boldsymbol 4}$ Battery Based on a Novel Thermoelectric Model
Abstract:
Li-ion batteries have been widely used in electric vehicles, and battery internal state estimation plays an important role in the battery management system. However, it is technically challenging, in particular, for the estimation of the battery internal temperature and state-of-charge (SOC), which are two key state variables affecting the battery performance. In this paper, a novel method is proposed for realtime simultaneous estimation of these two internal states, thus leading to a significantly improved battery model for realtime SOC estimation. To achieve this, a simplified battery thermoelectric model is first built, which couples a thermal submodel and an electrical submodel. The interactions between the battery thermal and electrical behaviors are captured, thus offering a comprehensive description of the battery thermal and electrical behavior. To achieve more accurate internal state estimations, the model is trained by the simulation error minimization method, and model parameters are optimized by a hybrid optimization method combining a metaheuristic algorithm and the least-square approach. Further, time-varying model parameters under different heat dissipation conditions are considered, and a joint extended Kalman filter is used to simultaneously estimate both the battery internal states and time-varying model parameters in realtime. Experimental results based on the testing data of LiFePO batteries confirm the efficacy of the proposed method.
Autors: Cheng Zhang;Kang Li;Jing Deng;Shiji Song;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 654 - 663
Publisher: IEEE
 
» Improved Surface Modification of Polymer Films by Energy-Compressed Dielectric Barrier Discharge With Discharge-Time-Regulated Power Source
Abstract:
An energy-compressed dielectric barrier discharge (DBD) in the atmospheric-pressure air is established to improve the surface modification of the polymer films. The effective discharge time of per repetitive cycle in the DBD system is adjusted by employing an active regulated power source, which can compress the energy transferred to the DBD load in the time domain. The effect of the energy compression on the surface modification of the polyethylene films is studied at different energy densities and frequencies by using the contact angle measurement, the atomic force microscope, and the X-ray photoelectron spectroscope. The results show that, at the given energy density and frequency, the surface wettability is improved by increasing the energy compression degree due to the higher surface roughness and more oxygen-containing polar functional groups. Furthermore, less energy density is needed to achieve the same level of surface wettability by increasing the energy compression degree. The reasons for the high performance of the energy-compressed DBD are the increase of the reactive species density and the enhancement of the physical and chemical interactions. As a result, the energy-compressed DBD is a superior solution for the polymer surface modification.
Autors: Shiqiang Hao;Wuhua Li;Xiaowei Gu;Xiangning He;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2017, volume: 45, issue:1, pages: 60 - 67
Publisher: IEEE
 
» Improving 3D Character Posing with a Gestural Interface
Abstract:
The most time-consuming part of character animation is 3D character posing. Posing using a mouse is a slow and tedious task that involves sequences of selecting on-screen control handles and manipulating the handles to adjust character parameters, such as joint rotations and end effector positions. Thus, various 3D user interfaces have been proposed to make animating easier, but they typically provide less accuracy. The proposed interface combines a mouse with the Leap Motion device to provide 3D input. A usability study showed that users preferred the Leap Motion over a mouse as a 3D gestural input device. The Leap Motion drastically decreased the number of required operations and the task completion time, especially for novice users.
Autors: Mikko Kytö;Krupakar Dhinakaran;Aki Martikainen;Perttu Hämäläinen;
Appeared in: IEEE Computer Graphics and Applications
Publication date: Jan 2017, volume: 37, issue:1, pages: 70 - 78
Publisher: IEEE
 
» Improving Convergence and Simulation Time of Quantum Hydrodynamic Simulation: Application to Extraction of Best 10-nm FinFET Parameter Values
Abstract:
As electronic devices enter the deep nanometer regime, accurate and efficient device simulations become necessary to account for the emerging quantum effects. The traditional drift-diffusion and hydrodynamic (HD) device simulation models are not accurate in this regime. It is important to use the quantum HD (QHD) simulation model. However, this model suffers from poor convergence and high CPU times. To overcome these obstacles, in this paper, we propose a novel method to replace part of the QHD simulation that exhibits poor convergence behavior and high CPU time with HD simulation. In order to implement this, we capture the device states from the classical HD model and then apply the results as the initial guess to the QHD simulation, which is then solved by the Newton-Raphson method. This leads to significant improvements. The nonconvergence rate and the simulation time are reduced by 86.0% and 30.2%, respectively. As an application of the proposed methodology, we extract the best parameter values of both bulk and silicon-on-insulator FinFETs at the 10-nm technology node from their vast device design space.
Autors: Xiaoliang Dai;Niraj K. Jha;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jan 2017, volume: 25, issue:1, pages: 319 - 329
Publisher: IEEE
 
» Improving Orthorectification of UAV-Based Push-Broom Scanner Imagery Using Derived Orthophotos From Frame Cameras
Abstract:
Low-cost unmanned airborne vehicles (UAVs) are emerging as a promising platform for remote-sensing data acquisition to satisfy the needs of wide range of applications. Utilizing UAVs, which are equipped with directly georeferenced RGB-frame cameras and hyperspectral push-broom scanners, for precision agriculture and high-throughput phenotyping is an important application that is gaining significant attention from researchers in the mapping and plant science fields. The advantages of UAVs as mobile-mapping platforms include low cost, ease of storage and deployment, ability to fly lower and collect high-resolution data, and filling an important gap between wheel-based and manned-airborne platforms. However, limited endurance and payload are the main disadvantages of consumer-grade UAVs. These limitations lead to the adoption of low-quality direct georeferencing and imaging systems, which in turn will impact the quality of the delivered products. Thanks to recent advances in sensor calibration and automated triangulation, accurate mapping using low-cost frame imaging systems equipped with consumer-grade georeferencing units is feasible. Unfortunately, the quality of derived geospatial information from push-broom scanners is quite sensitive to the performance of the implemented direct georeferencing unit. This paper presents an approach for improving the orthorectification of hyperspectral push-broom scanner imagery with the help of generated orthophotos from frame cameras using tie point and linear features, while modeling the impact of residual artifacts in the direct georeferencing information. The performance of the proposed approach has been verified through real datasets that have been collected by quadcopter and fixed-wing UAVs over an agricultural field.
Autors: Ayman Habib;Weifeng Xiong;Fangning He;Hsiuhan Lexie Yang;Melba Crawford;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 262 - 276
Publisher: IEEE
 
» Improving Our Bodies, Our Meals, and Our Gadgets
Abstract:
This installment of Notes from the Community covers new pervasive technologies using metamaterials, flexible and stretchable electronics, sensors, robotics, 3D printing, tofu, and more.
Autors: Mary Baker;Justin Manweiler;
Appeared in: IEEE Pervasive Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 85 - 88
Publisher: IEEE
 
» Improving Pulp and Paper Plant MV Transformer Protection
Abstract:
In pulp and paper plants, power transformers play a critical role in process continuity. These transformers are subject to internal short circuits, external short circuits, and abnormal operating conditions. The following protection challenges to power transformers will be explored, and methods to improve the protection are provided. First, remanence in a current transformer (CT) may cause misoperation of phase differential protection due to compromised CT performance. Heavy through-faults, sympathetic inrush, and recovery inrush all cause high current. This, combined with high remanent flux, can create a security issue. IEEE CT performance calculations will be used to support the use of dual slope differential characteristics to promote secure differential protection operation when challenged with unequal CT performance. Second, on transformer energizing, the second harmonic current has been traditionally used as a means to prevent phase differential misoperation. Certain transformers may not exhibit high enough the second harmonic, causing a dependability issue if the restraint is set too low. The use of the second and fourth harmonics for inrush detection will be shown to enhance the reliability during energizing inrush situations. Third, overexcitation can occur from abnormal operation of the utility system or the plant's excitation control. Causes of overexcitation will be outlined and the use of volts per hertz protection is explored. With overexcitation occurring from system voltage rise, the phase differential protection has been traditionally blocked using the fifth harmonic restraint. This may cause an undesired nonoperation of the phase differential protection if an internal fault occurs while the transformer is overexcited, causing a delay in tripping and severe damage to the transformer. A technique using adaptive phase differential pickup value will be illustrated to overcome this challenge.�- A0;Finally, on resistance-grounded power transformers, phase differential protection sensitivity for ground faults near the neutral is decreased. The use of ground differential protection will be explored and the increased sensitivity gained will be demonstrated.
Autors: Wayne Hartmann;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 758 - 765
Publisher: IEEE
 
» IMS2016 Student Design Competitions
Abstract:
Presents information on the IMS 2016 Student Design competitions.
Autors: Rober Caverly;
Appeared in: IEEE Microwave Magazine
Publication date: Jan 2017, volume: 18, issue:1, pages: 56 - 57
Publisher: IEEE
 
» In Memoriam
Abstract:
Autors: Hideki Miyajima;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 3
Publisher: IEEE
 
» In Memoriam Soshin Chikazumi
Abstract:
Recounts the life and career of Soshin Chikazumi, the second president of the Magnetics Society of Japan.
Autors: Hideki Miyajima;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 3
Publisher: IEEE
 
» In-Band Wireless Information and Power Transfer With Lens Antenna Array
Abstract:
This letter studies a new wireless information and power transfer coexisting system, where two uncoordinated energy and information sources simultaneously transmit to the same receiver for energy harvesting and information reception, respectively. In such a setup, the information decoder could suffer from severe signal distortion due to the simultaneously received energy signal that is usually orders-of-magnitude stronger than the desired information signal. To tackle this practical issue, we propose a novel lens antenna array-enabled receiver, which exploits the angle-of-arrival-dependent energy focusing capability of lens array for the spatial separation of energy and information signals. In addition, an optimal power splitting-based scheme is proposed by taking into account the signal distortion effect at the receiver, which is applicable for both lens and conventional antenna arrays. Numerical results show that the proposed lens array receiver significantly outperforms that with the conventional uniform planar array in terms of an achievable rate-energy tradeoff.
Autors: Lu Yang;Yong Zeng;Rui Zhang;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 100 - 103
Publisher: IEEE
 
» In-Memory Parallel Processing of Massive Remotely Sensed Data Using an Apache Spark on Hadoop YARN Model
Abstract:
MapReduce has been widely used in Hadoop for parallel processing larger-scale data for the last decade. However, remote-sensing (RS) algorithms based on the programming model are trapped in dense disk I/O operations and unconstrained network communication, and thus inappropriate for timely processing and analyzing massive, heterogeneous RS data. In this paper, a novel in-memory computing framework called Apache Spark (Spark) is introduced. Through its merits of transferring transformation to in-memory datasets of Spark, the shortages are eliminated. To facilitate implementation and assure high performance of Spark-based algorithms in a complex cloud computing environment, a strip-oriented parallel programming model is proposed. By incorporating strips of RS data with resilient distributed datasets (RDDs) of Spark, all-level parallel RS algorithms can be easily expressed with coarse-grained transformation primitives and BitTorrent-enabled broadcast variables. Additionally, a generic image partition method for Spark-based RS algorithms to efficiently generate differentiable key/value strips from a Hadoop distributed file system (HDFS) is implemented for concealing the heterogeneousness of RS data. Data-intensive multitasking algorithms and iteration-intensive algorithms were evaluated on a Hadoop yet another resource negotiator (YARN) platform. Experiments indicated that our Spark-based parallel algorithms are of great efficiency, a multitasking algorithm took less than 4 h to process more than half a terabyte of RS data on a small YARN cluster, and 9*9 convolution operations against a 909-MB image took less than 260 s. Further, the efficiency of iteration-intensive algorithms is insensitive to image size.
Autors: Wei Huang;Lingkui Meng;Dongying Zhang;Wen Zhang;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 3 - 19
Publisher: IEEE
 
» In-Vehicle Emergency Call Services: eCall and Beyond
Abstract:
What is the status of in-vehicle emergency call services? Which standards are being adopted? Does the NG-911/112 architecture support such services? The objective of this article is to address these questions. To do so we review the evolution of eCall, compare approaches developed in different parts of the world, and discuss interoperability between selected systems. This study shows that it is challenging to compare and classify in-vehicle emergency call systems because of different standards, terminologies, and proprietary specifications. We conclude that the NG-911/112 framework provides the building blocks to support next generation eCall, and can contribute to a common standard for the interface between private service centers and public safety answering points.
Autors: Risto Oorni;Ana Goulart;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2017, volume: 55, issue:1, pages: 159 - 165
Publisher: IEEE
 
» Incident-Supporting Visual Cloud Computing Utilizing Software-Defined Networking
Abstract:
In the event of natural or man-made disasters, providing rapid situational awareness through video/image data collected at salient incident scenes is often critical to the first responders. However, computer vision techniques that can process the media-rich and data-intensive content obtained from civilian smartphones or surveillance cameras require large amounts of computational resources or ancillary data sources that may not be available at the geographical location of the incident. In this paper, we propose an incident-supporting visual cloud computing solution by defining a collection, computation, and consumption (3C) architecture supporting fog computing at the network edge close to the collection/consumption sites, which is coupled with cloud offloading to a core computation, utilizing software-defined networking (SDN). We evaluate our 3C architecture and algorithms using realistic virtual environment test beds. We also describe our insights in preparing the cloud provisioning and thin-client desktop fogs to handle the elasticity and user mobility demands in a theater-scale application. In addition, we demonstrate the use of SDN for on-demand compute offload with congestion-avoiding traffic steering to enhance remote user quality of experience in a regional-scale application. The optimization between fogs computing at the network edge with core cloud computing for managing visual analytics reduces latency, congestion, and increases throughput.
Autors: Rasha Gargees;Brittany Morago;Rengarajan Pelapur;Dmitrii Chemodanov;Prasad Calyam;Zakariya Oraibi;Ye Duan;Guna Seetharaman;Kannappan Palaniappan;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jan 2017, volume: 27, issue:1, pages: 182 - 197
Publisher: IEEE
 
» Incoherent Photonic Processing for Chirped Microwave Pulse Generation
Abstract:
We propose and experimentally demonstrate a fully reconfigurable generator of chirped microwave pulses based on the processing of an incoherent optical signal by means of a dispersive element with a non-uniform optical spectral shaping. The system performance has been proven by the generation of different chirped microwave pulses. Different capabilities of the system have been experimentally demonstrated as frequency tunability and time-bandwidth product control by means of the dispersive element and optical source power distribution. Furthermore, the possibility for generating chirped microwave pulses with positive and negative chirp characteristic has been shown achieving similar chirps in terms of magnitude but opposite sign. For it, the chirp characteristic is introduced by proper shaping of the optical source signal power distribution.
Autors: M. Rius;M. Bolea;J. Mora;J. Capmany;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2017, volume: 29, issue:1, pages: 7 - 10
Publisher: IEEE
 
» Incoherent Unit-Norm Frame Design via an Alternating Minimization Penalty Method
Abstract:
This letter is concerned with designing incoherent unit-norm frames, i.e., a set of vectors in a finite dimensional Hilbert space with unit norms and very low absolute pairwise correlations. Due to their widespread use in a variety of applications, including compressed sensing and coding theory, incoherent frame design has received considerable attention, and many algorithms have been proposed to this aim. In this letter, a new algorithm is presented which constructs incoherent frames by minimizing the maximum absolute pairwise correlations (mutual coherence) of the frame vectors. Our strategy is based on an alternating minimization penalty method, which admits efficient solvers using proximal algorithms. Experimental results on designing incoherent frames of various dimensions show that our algorithm outperforms some recent methods in the literature.
Autors: Mostafa Sadeghi;Massoud Babaie-Zadeh;
Appeared in: IEEE Signal Processing Letters
Publication date: Jan 2017, volume: 24, issue:1, pages: 32 - 36
Publisher: IEEE
 
» Incoming EIC Editorial
Abstract:
Presents the incoming editorial by the new Editor-In-Chief.
Autors: Sven Dickinson;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2017, volume: 39, issue:1, pages: 3 - 4
Publisher: IEEE
 
» Increasing DNS Security and Stability through a Control Plane for Top-Level Domain Operators
Abstract:
We present a control plane for operators of top-level domains (TLDs) in the DNS, such as “.org” and “.nl,” that enables them to increase the security and stability of their TLD by taking on the role of a threat intelligence provider. Our control plane is a novel system that extends a TLD operator’s traditional services and detects potential threats in the TLD by continuously analyzing the TLD operator’s two key datasets: the typically large amounts of DNS traffic that it handles and its database of registered domain names. The control plane shares information on discovered threats with other players in the TLD’s ecosystem and can also use it to dynamically scale the TLD operator’s DNS infrastructure. The control plane builds on a set of open source modules that we have developed on top of a Hadoop-based data storage cluster. These enable, for example, TLD operators to run and develop threat detectors and to easily import their DNS traffic into the control plane. Our control plane uses policies to protect the privacy of TLD users and is based on our operational experience of running .nl TLD (Netherlands), which we are also using as the use case for our implementation.
Autors: Cristian Hesselman;Giovane C. M. Moura;Ricardo de Oliveira Schmidt;Cees Toet;
Appeared in: IEEE Communications Magazine
Publication date: Jan 2017, volume: 55, issue:1, pages: 197 - 203
Publisher: IEEE
 
» Increasing flexibility and capacity in real PON deployments by using 2/4/8-PAM formats
Abstract:
Current passive optical networks (PONs) use on–off keying (OOK) modulation throughout the entire network regardless of actual path losses. Statistics of commercial gigabit passive optical network (GPON) deployments show significant path loss differences among the optical network units (ONUs). Flexible 4- and 8-level pulse amplitude modulation (4/8-PAM) allocation for the better-situated ONUs can significantly increase the PON’s aggregated data rate. By keeping to intensity modulation direct detection (IM-DD) modulation and a constant symbol rate, the introduction of adaptive, multilevel PAM does not require expensive optics investments; additionally, 8-PAM is made feasible with zero-overhead data-aided equalization. Two scenarios for distributing the extra capacity are explored: first, controlling the dynamic bandwidth allocation of the time division multiplexed PON (TDM-PON) to provide equal time-length slots to both 4/8-PAM ONUs and OOK ONUs, thereby providing maximum aggregated capacity increase; and second, setting up the dynamic bandwidth allocation to provide equal capacity slots to the various ONUs so the entire ONU population in the same PON can benefit from the extra capacity. Both scenarios result in a larger aggregated capacity of the PON and provide additional options for the network operator during the network design phase.
Autors: R. Van Der Linden;N. C. Tran;E. Tangdiongga;A. M. J. Koonen;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Jan 2017, volume: 9, issue:1, pages: A1 - A8
Publisher: IEEE
 
» Incremental Subgraph Feature Selection for Graph Classification
Abstract:
Graph classification is an important tool for analyzing data with structure dependency, where subgraphs are often used as features for learning. In reality, the dimension of the subgraphs crucially depends on the threshold setting of the frequency support parameter, and the number may become extremely large. As a result, subgraphs may be incrementally discovered to form a feature stream and require the underlying graph classifier to effectively discover representative subgraph features from the subgraph feature stream. In this paper, we propose a primal-dual incremental subgraph feature selection algorithm (ISF) based on a max-margin graph classifier. The ISF algorithm constructs a sequence of solutions that are both primal and dual feasible. Each primal-dual pair shrinks the dual gap and renders a better solution for the optimal subgraph feature set. To avoid bias of ISF algorithm on short-pattern subgraph features, we present a new incremental subgraph join feature selection algorithm (ISJF) by forcing graph classifiers to join short-pattern subgraphs and generate long-pattern subgraph features. We evaluate the performance of the proposed models on both synthetic networks and real-world social network data sets. Experimental results demonstrate the effectiveness of the proposed methods.
Autors: Haishuai Wang;Peng Zhang;Xingquan Zhu;Ivor Wai-Hung Tsang;Ling Chen;Chengqi Zhang;Xindong Wu;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Jan 2017, volume: 29, issue:1, pages: 128 - 142
Publisher: IEEE
 
» Inertia Provision and Estimation of PLL-Based DFIG Wind Turbines
Abstract:
This paper presents an alternative inertial control method for doubly fed induction generator (DFIG)-based wind turbines by directly adjusting the phase locked loop (PLL) response. The synthetic internal voltage vector of the wind turbine-driven DFIG is defined in the electromechanical timescale to present the dynamic properties. The phase angle motion equation is further deduced to depict the relationship between the contributed inertial response and the defined internal voltage. Based on the developed motion equation, the equivalent inertia is estimated and quantified, and further found to be significantly determined by the PLL parameters. Moreover, the effect of both PLL and active power control on the defined internal voltage dynamics is also described during the inertial response. Simulated results on a modified 3-machine, 9-node test system were conducted to validate the feasibility of the proposed inertial control method and the correctness of the developed inertial characteristics.
Autors: Wei He;Xiaoming Yuan;Jiabing Hu;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2017, volume: 32, issue:1, pages: 510 - 521
Publisher: IEEE
 
» Inference for Generalized Linear Models via Alternating Directions and Bethe Free Energy Minimization
Abstract:
Generalized linear models, where a random vector x is observed through a noisy, possibly nonlinear, function of a linear transform , arise in a range of applications in nonlinear filtering and regression. Approximate message passing (AMP) methods, based on loopy belief propagation, are a promising class of approaches for approximate inference in these models. AMP methods are computationally simple, general, and admit precise analyses with testable conditions for optimality for large i.i.d. transforms A. However, the algorithms can diverge for general A. This paper presents a convergent approach to the generalized AMP (GAMP) algorithm based on direct minimization of a large-system limit approximation of the Bethe free energy (LSL-BFE). The proposed method uses a double-loop procedure, where the outer loop successively linearizes the LSL-BFE and the inner loop minimizes the linearized LSL-BFE using the alternating direction method of multipliers (ADMM). The proposed method, called ADMM-GAMP, is similar in structure to the original GAMP method, but with an additional least-squares minimization. It is shown that for strictly convex, smooth penalties, ADMM-GAMP is guaranteed to converge to a local minimum of the LSL-BFE, thus providing a convergent alternative to GAMP that is stable under arbitrary transforms. Simulations are also presented that demonstrate the robustness of the method for non-convex penalties as well.
Autors: Sundeep Rangan;Alyson K. Fletcher;Philip Schniter;Ulugbek S. Kamilov;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2017, volume: 63, issue:1, pages: 676 - 697
Publisher: IEEE
 
» Influence of Lattice Mismatch in Preparation of the SmBiO3 Buffer Layer by a CSD Method
Abstract:
SmBiO3 (SBO) buffer layers have been prepared via a rapid chemical solution deposition (CSD) method on different substrates, such as LaAlO3 (LAO), yttrium-stabilized zirconium (YSZ), and NiO-buffered NiW (NiO/NiW). The SBO buffer layers deposited on LAO, YSZ, and NiO/NiW substrates have strong SBO (200) peaks and smooth surface. The SBO buffer layer is difficult to grow on the MgO substrate. The lattice mismatches between SBO buffer layers and different substrates have great influence on the epitaxial films quality. With the increase in lattice mismatch, the optimum texture temperature ranges become narrower, also the texture degrees of SBO epitaxial films decrease, and the SBO buffer layers become rougher.
Autors: Xiaolei Zhu;Ke Zhao;Liang Zheng;Ming Lei;Minghua Pu;Yong Zhang;Yong Zhao;
Appeared in: IEEE Transactions on Applied Superconductivity
Publication date: Jan 2017, volume: 27, issue:1, pages: 1 - 5
Publisher: IEEE
 
» Influence of LV Neutral Grounding on Global Earthing Systems
Abstract:
International Standards define a Global Earthing System as an earthing net created interconnecting local Earthing Systems (generally through the shield of MV cables and/or bare buried conductors). In Italy, the regulatory authority for electricity and gas requires distributors to guarantee the electrical continuity of LV neutral conductor. This requirement has led to the standard practice of realizing “reinforcement groundings” along the LV neutral conductor path and at users’ delivery cabinet. Moreover, in urban high-load scenarios (prime candidates to be part of a Global Earthing System), it is common that LV distribution scheme creates, through neutral conductors, an effective connection between grounding systems of MV/LV substations, modifying Global Earthing System consistency. The aim of this paper is to evaluate the effect, in terms of electrical safety, of the aforementioned LV neutral distribution scheme when an MV-side fault to ground occurs. For this purpose, simulations are carried out on a realistic urban test case and suitable evaluation indexes are proposed.
Autors: Giuseppe Cafaro;Pasquale Montegiglio;Francesco Torelli;Antonino Barresi;Pietro Colella;Angelo De Simone;Maria Luisa Di Silvestre;Luigi Martirano;Elena Reizl Morozova;Roberto Napoli;Giuseppe Parise;Luigi Parise;Enrico Pons;Eleonora Riva Sanseverino;Ri
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 22 - 31
Publisher: IEEE
 
» Influence of PM- and Armature Winding-Stator Positions on Electromagnetic Performance of Novel Partitioned Stator Permanent Magnet Machines
Abstract:
Since the permanent magnets (PMs) and armature windings of partitioned stator (PS) PM machines are located in two separate inner and outer stators, their positions can be exchanged to optimize the space utilization, especially in radial field rotating machines. Therefore, in this paper, the influence of PM and armature winding stator positions on the electromagnetic performance of PS-PM machines is investigated based on the novel PS-PM machines (PS-PMMs) with surface-mounted PM (SPM) stator. Similar to the single-stator surface-mounted PMMs (SS-PMMs), flexible rotor pole number, bipolar phase flux linkage, and symmetrical phase back electromotive force (EMF) are also obtained in PS-PMMs. Based on the same 12/10 stator/rotor pole number combination, PS-PMM-I (PMs located in the inner stator) and PS-PMM-II (PMs located in the outer stator) exhibit 120% and 160% higher phase back EMFs as well as 120% and 139% larger average torques, respectively, than the SS-PMM together almost without scarifying the PM utilization efficiency under the same machine size and the same rated copper loss. Further, the proposed PS-PMM-IIs have both higher phase back EMFs and larger average torques than PS-PMM-Is among all the main stator/rotor pole number combinations. Meanwhile, for both PS-PMM-Is and PS-PMM-IIs with 12-pole stator, the machines with the 11-pole rotor exhibit the optimal torque capabilities. Moreover, the reluctance torque is also negligible in the proposed PS-PMMs due to very low saliency ratio. The analyses are validated by experiment results of the prototype machine.
Autors: J. T. Shi;A. M. Wang;Z. Q. Zhu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 12
Publisher: IEEE
 
» Influence of Rotor Topologies and Cogging Torque Minimization Techniques in the Detection of Static Eccentricities in Axial-Flux Permanent-Magnet Machine
Abstract:
In this paper, the effect of static eccentricity on current harmonics and torque ripple in an axial-flux permanent-magnet machine with fractional-slot concentrated winding is investigated. Cogging torque minimization techniques are also explored in the presence of the anomaly to better understand their sensitivity to the condition. Also, the impact of single-sided and double-sided rotor topologies on both current harmonics and torque ripple is examined. It is found that static eccentricities incite significant increases in the amplitudes of space and subharmonics in the single-sided topology, which may be mitigated by the cogging torque minimization techniques. The double-sided topology is tolerant to the presence of static eccentricities unlike the single-sided topology; this is due to the opposing effect of the resulting asymmetrical properties of the air gap. Finally, this paper establishes a detection technique for static eccentricities in single-sided axial-flux permanent-magnet machine whereby the cogging torque minimization techniques do not impair on them.
Autors: Oladapo Omotade Ogidi;Paul S. Barendse;Mohamed Azeem Khan;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 161 - 170
Publisher: IEEE
 
» Influence of the Heterojunction Spacer on the Performance of AlGaN/GaN/AlGaN Resonant Tunneling Diodes
Abstract:
We report on a simulation for an aluminum gallium nitride (AlGaN)/gallium nitride (GaN) resonant tunneling diode (RTD) with a step heterojunction emitter spacer (SHES) at room temperature. An SHES and low Al component barriers were introduced in to AlGaN/GaN RTDs to improve the electronic injection efficiency in to the emitter, reduce the transit time in the collector depletion region, and achieve lattice matching. The substitution of the emitter spacer for the SHES alters the dominant transport mechanism, increases the tunneling current, and restrains the thermionic current. As a result, the peak current was 1.683 A at 0.39 V and the peak-to-valley current difference was 0.93 A.
Autors: Bo Gao;Yao Ma;Yang Liu;Min Gong;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 84 - 88
Publisher: IEEE
 
» Informed Fixed Scheduling for Faster Convergence of Shuffled Belief-Propagation Decoding
Abstract:
A novel informed fixed scheduling (IFS) scheme for shuffled belief-propagation (BP) decoding of binary low-density parity-check (LDPC) code is introduced to improve the BP decoding convergence. The IFS finds an appropriate order of variable nodes in accordance with the number of updated neighbors in the code graph, ensuring that the maximum number of latest message updates is utilized within a single iteration. This allows the utilization of most reliable message updates in a timely manner, leading to faster error-rate convergence. Simulation results show that the proposed IFS scheme improves the convergence speed of BP decoder by up to 20% for regular LDPC codes and 45% for irregular LDPC codes, without affecting the error-rate performance, at medium-to-high signal-to-noise ratio over binary-input additive white Gaussian noise channel.
Autors: Chaudhry Adnan Aslam;Yong Liang Guan;Kui Cai;Guojun Han;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 32 - 35
Publisher: IEEE
 
» Infrared and Terahertz Modulation Characteristics of n-GeBi/p-Si Photodiodes
Abstract:
In this paper, germanium–bismuth (Ge1–xBix, –0.32) is grown by low-temperature molecular beam epitaxy. Because Bi is an element belonging to group V, GeBi films show inherent n-type doping properties compared with GeSn ones. Inherent n-type Ge1–xBix films with a doping concentration of –/cm3 are epitaxially deposited on p-type Si substrates to form p-n junctions. Current–voltage measurements show that the dark current density of the diodes can approach 0.32 A/cm2. The influence of Bi concentration on the infrared (IR) and terahertz (THz) transmittance of the films is investigated. Near-IR (1–2 ) and mid/far-IR (2.6–10 ) responsivities of the films are 0.65 and 0.032 A/W, respectively. The THz wave transmittance is tuned by ~6%–8% by tailoring the bias voltage. A modulation depth of ~12% is obtained for a Ge0.78Bi0.22/p-Si diode. The dynamic modulation characteristics of n-Ge1–xBix/p-Si diodes are further investigated using a 340-GHz carrier. The experimental maximum THz wave modulation speed is up to 2 MHz. The present results demonstrate that n-GeBi- p-Si diodes are promising for both mid/far-IR photodetectors and broadband high-speed THz wave modulators.
Autors: Dainan Zhang;Lichuan Jin;Yulong Liao;Yang Liu;Tianlong Wen;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 176 - 181
Publisher: IEEE
 
» Initial Rotor Position Estimation Using Zero-Sequence Carrier Voltage for Permanent-Magnet Synchronous Machines
Abstract:
Both rotating and anticlockwise pulsating signal injection methods based on zero-sequence voltage sensing have been reported to have large signal-to-noise ratio and bandwidths, and great stability for the sensorless control of permanent-magnet synchronous machines. However, the initial rotor position estimation and magnetic polarity identification using zero-sequence voltage have not been investigated. Therefore, this paper presents two types of magnetic polarity identification methods, based on the amplitude variation of zero-sequence voltage due to saturation changing, and based on the secondary harmonics of zero-sequence voltage, for the two carrier injection methods, respectively. It is found that the amplitude variation based method using zero-sequence voltage has higher detection sensitivity for the real magnetic polarity compared to the conventional method using the carrier current. In contrast, the secondary harmonic based identification method using zero-sequence voltage for rotating signal injection has the advantage of fast response, and moreover has large signal amplitude and less distortion compared to the conventional secondary carrier current harmonics. However, the secondary harmonic method loses the capability for polarity detection for the anticlockwise pulsating injection method. Experiments are carried out on a laboratory permanent-magnet machine to verify the theoretical analyses.
Autors: Peilin Xu;Z. Q. Zhu;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 149 - 158
Publisher: IEEE
 
» Innovation in Transfer Assist Technologies for Persons with Severe Disabilities and Their Caregivers
Abstract:
When the human body is immobile, it deteriorates after a short period of time. Early and frequent mobilization of a patient or resident is thus critical to maintaining or regaining health. The effects of immobility are often a deterioration of numerous body systems and increased dependence on caregivers to assist with activities of daily living [1]. Complications associated with chronic immobility include patient injury, development of pressure ulcers, muscle atrophy, metabolic decline, joint contractures, microvascular dysfunction, atelectasis, thromboembolic disease, and psychological decline. These complications are exacerbated in the case of an obese patient.
Autors: Andrew Sivaprakasam;Hongwu Wang;Rory A. Cooper;Alicia M. Koontz;
Appeared in: IEEE Potentials
Publication date: Jan 2017, volume: 36, issue:1, pages: 34 - 41
Publisher: IEEE
 
» Innovative Robust Modulation Classification Using Graph-Based Cyclic-Spectrum Analysis
Abstract:
A novel automatic modulation classification method based on the graph presentation of the cyclic spectrum is proposed. In our proposed scheme, the periodicity and the symmetry of the cyclic spectrum will be exploited to establish a concise feature representation of multiple graphs. The modulated signal is first transformed from the cycle-frequency domain into the graph domain. Consequently, the concise graph-presentation, namely, a set of weighted directed rings, will be formulated as the robust features of the original signal. Those features can be easily expressed by the corresponding adjacency matrices. It can be verified that the adjacency matrices are sparse and the non-zero entries therein can be registered as the efficient feature parameters. Through the Hamming distance measure to enumerate the difference between the feature parameters resulting from the training data and the test data, one can perform the modulation classification. Monte Carlo simulation results demonstrate that our proposed method can achieve much better classification accuracy than the existing technique when the cyclic spectrum is used.
Autors: Xiao Yan;Guoyu Feng;Hsiao-Chun Wu;Weidong Xiang;Qian Wang;
Appeared in: IEEE Communications Letters
Publication date: Jan 2017, volume: 21, issue:1, pages: 16 - 19
Publisher: IEEE
 
» Instantaneous Baseline Damage Localization Using Sensor Mapping
Abstract:
In this paper, an instantaneously recorded baseline method is proposed using piezoelectric transducers for damage localization under varying temperature. This method eliminates need for baselines required when operating at different temperatures by mapping a baseline area onto the interrogation area. Instantaneously recorded baselines and current interrogation signals are calibrated based on the sensor mapping. This allows the extraction of damage scatter signal which is used to localize damage. The proposed method is used to localize actual impact damage on a composite plate under varying temperatures. The method is also applied to a stiffened fuselage panel to accurately localize impact damage.
Autors: Mohammad Saleh Salmanpour;Zahra Sharif Khodaei;Mohammad Hossein Aliabadi;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2017, volume: 17, issue:2, pages: 295 - 301
Publisher: IEEE
 
» Integrated Inductor and Capacitor With Co-Located Electric and Magnetic Fields
Abstract:
Passive components such as inductors and capacitors are fundamental components of nearly all power electronic conversion systems. This paper presents an innovative approach to highly integrated inductor (L) and capacitor (C) design by storing magnetic and electric field energy in a common volume, constituting a dual energy core (DEC). This is dissimilar from other integrated designs that primarily exploit a distributed parasitic capacitance between planar inductor windings, ultimately parsing electric, and magnetic fields into separate locations unnecessarily. The DEC enables a four terminal integrated LC device that may be applied in series, parallel, or in separate parts of the circuit, since its terminal characteristics appear as decoupled lumped elements. The fields in the core geometry are analytically modeled and the effects and tradeoffs of selecting different core parameters/dimensions are explored. Proof of concept prototypes of toroidal form factor demonstrate techniques for fabricating DEC integrated devices, and experimental measurements correlate with the analytical models used in the design process. A boost converter is constructed and tested with a prototype integrated device to demonstrate decoupled operation of the fields in the core on a large signal basis.
Autors: Andy Schroedermeier;Daniel C. Ludois;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 380 - 390
Publisher: IEEE
 
» Integrating Object Boundary in Super-Resolution Land-Cover Mapping
Abstract:
This paper proposes a novel class allocation strategy in units of object (UOO) for soft-then-hard super-resolution mapping (STHSRM). STHSRM involves two processes: 1) subpixel sharpening and 2) class allocation. The UOO is implemented in the second process by integrating the object boundaries as an additional structural constraint. First, UOO obtains the object boundaries from remote-sensing images by image segmentation. The number of subpixels within an object is then calculated for each class to meet the coherence constraint of fractional images imposed by soft classification. Finally, a linear optimization model is built for each object to obtain the optimal hard class labels of subpixels. A synthetic image and two real remote-sensing images are used to evaluate the effectiveness of UOO. The results are compared visually and quantitatively with two existing class allocation methods: 1) the highest attribute values first (HAVF) and 2) units of class (UOC). The experimental results show that UOO performs better than these two methods. UOO can better reduce the salt and pepper effect in resultant maps than both HAVF and UOC when dealing with real remote-sensing images. Moreover, UOO can better maintain the structure of land-cover patches, with smoother boundaries as compared with the two methods.
Autors: Yuehong Chen;Yong Ge;Yuanxin Jia;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 219 - 230
Publisher: IEEE
 
» Integration of Gate Recessing and In Situ Cl Doped Al2O3 for Enhancement-Mode AlGaN/GaN MOSHEMTs Fabrication
Abstract:
This letter demonstrates an integration process of in situ Cl doped Al2O3 and gate recess technique to fabricate the enhancement mode AlGaN/GaN MOSHEMTs. The Cl doped Al2O3 thin film is deposited by the ultrasonic spray pyrolysis deposition and characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The relative permittivity of Cl doped Al2O3 is higher than the pure Al2O3 and the output current is enhanced. The threshold voltage of the enhancement mode AlGaN/GaN MOSHEMT with the Cl doped Al2O3 gate dielectric layer rose from 0.2 to 1.3 V. Furthermore, the breakdown voltage of present enhancement mode AlGaN/GaN MOSHEMT reached 650 V. It was also found that the MOSHEMT with Cl doped Al2O3 has higher gate leakage than that with pure Al2O3. The thermal stability of threshold voltage and current collapse phenomenon is described in this letter.
Autors: Han-Yin Liu;Chih-Wei Lin;Wei-Chou Hsu;Ching-Sung Lee;Meng-Hsueh Chiang;Wen-Ching Sun;Sung-Yen Wei;Sheng-Min Yu;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2017, volume: 38, issue:1, pages: 91 - 94
Publisher: IEEE
 
» Intense-Mode Vacuum Arc Characterization by Using 2-D Electron and Vapor Density Image
Abstract:
Shack-Hartmann type laser wavefront sensors were applied to simultaneous single-shot imaging of 2-D electron and copper-vapor density distributions over intense-mode vacuum arc discharges with a pulsed current waveform of 800 A in peak and 24 in damping time constant. A parametric analysis of the ion current based on our experimental results suggested that the intense-mode arcs included highly energetic ions moving from cathodes to anodes with a high velocity of m/s and their proportion was larger than or comparable to slow ions with m/s drifted from anodes to cathodes by the electric fields. Furthermore, hydrodynamic calculation demonstrated that the copper vapor in the vacuum plasmas dissipated almost instantaneously in a time scale of and it was not residual metal medium but fresh one continuously supplied from the electrodes.
Autors: Yuki Inada;Tomoki Kamiya;Shigeyasu Matsuoka;Akiko Kumada;Hisatoshi Ikeda;Kunihiko Hidaka;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2017, volume: 45, issue:1, pages: 129 - 139
Publisher: IEEE
 
» Intensity and Compactness Enabled Saliency Estimation for Leakage Detection in Diabetic and Malarial Retinopathy
Abstract:
Leakage in retinal angiography currently is a key feature for confirming the activities of lesions in the management of a wide range of retinal diseases, such as diabetic maculopathy and paediatric malarial retinopathy. This paper proposes a new saliency-based method for the detection of leakage in fluorescein angiography. A superpixel approach is firstly employed to divide the image into meaningful patches (or superpixels) at different levels. Two saliency cues, intensity and compactness, are then proposed for the estimation of the saliency map of each individual superpixel at each level. The saliency maps at different levels over the same cues are fused using an averaging operator. The two saliency maps over different cues are fused using a pixel-wise multiplication operator. Leaking regions are finally detected by thresholding the saliency map followed by a graph-cut segmentation. The proposed method has been validated using the only two publicly available datasets: one for malarial retinopathy and the other for diabetic retinopathy. The experimental results show that it outperforms one of the latest competitors and performs as well as a human expert for leakage detection and outperforms several state-of-the-art methods for saliency detection.
Autors: Yitian Zhao;Yalin Zheng;Yonghuai Liu;Jian Yang;Yifan Zhao;Duanduan Chen;Yongtian Wang;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2017, volume: 36, issue:1, pages: 51 - 63
Publisher: IEEE
 
» Interaction Models and Automated Control under Partial Observable Environments
Abstract:
The problem of automatically constructing a software component such that when executed in a given environment satisfies a goal, is recurrent in software engineering. Controller synthesis is a field which fits into this vision. In this paper we study controller synthesis for partially observable LTS models. We exploit the link between partially observable control and non-determinism and show that, unlike fully observable LTS or Kripke structure control problems, in this setting the existence of a solution depends on the interaction model between the controller-to-be and its environment. We identify two interaction models, namely Interface Automata and Weak Interface Automata, define appropriate control problems and describe synthesis algorithms for each of them.
Autors: Daniel Ciolek;Victor Braberman;Nicolás D’Ippolito;Nir Piterman;Sebastián Uchitel;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Jan 2017, volume: 43, issue:1, pages: 19 - 33
Publisher: IEEE
 
» Interactive Exploration of 3D Scanned Baggage
Abstract:
An interactive visualization system can support volumetric data exploration in airport security screenings by addressing the challenges unique to the baggage inspection. The proposed system includes a set of interaction techniques that combine the direct manipulation of voxels and their interactive visualization. The system's final tools and GUI design incorporate feedback from airport personnel and were validated by real-world users in terms of effectiveness and ease of use.
Autors: Michael Traoré;Christophe Hurter;
Appeared in: IEEE Computer Graphics and Applications
Publication date: Jan 2017, volume: 37, issue:1, pages: 27 - 33
Publisher: IEEE
 
» Interface Magnetic and Electrical Properties of CoFeB /InAs Heterostructures
Abstract:
Amorphous magnetic CoFeB ultrathin films have been synthesized on the narrow band gap semiconductor InAs(100) surface, and the nature of the interface magnetic anisotropy and electrical contact has been studied. Angle-dependent hysteresis loops reveal that the films have an in-plane uniaxial magnetic anisotropy (UMA) with the easy axis along the InAs [0-11] crystal direction. The UMA was found to be dependent on the annealing temperatures of the substrates, which indicates the significant role of the Fe, Co-As bonding at the interface related to the surface condition of the InAs(100). – measurements show an ohmic contact interface between the CoFeB films and the InAs substrates, which is not affected by the surface condition of the InAs (100).
Autors: Zhenyao Wu;Xuezhong Ruan;Hongqing Tu;Pei Yang;Xiaoqian Zhang;Wenqing Liu;Bo Liu;Junran Zhang;Liang He;Jun Du;Rong Zhang;Yongbing Xu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2017, volume: 53, issue:1, pages: 1 - 4
Publisher: IEEE
 
» Interference and Resource Management Through Sleep Mode Selection in Heterogeneous Networks
Abstract:
This paper investigates the capacity and energy consumption metrics of small-cell networks that are enabled with sleep mode (SL) functionality. A novel method is introduced to systematically and accurately identify the potential SL cells that can maximize the spectrum reuse efficiency without the need for an exhaustive search. The performance of the proposed technique is assessed and compared with the always-on approach and an optimal benchmark. The results show that the proposed method significantly outperforms the always-on system and approaches the performance of the optimal benchmark with notably reduced computational burden.
Autors: Aysha Ebrahim;Emad Alsusa;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 257 - 269
Publisher: IEEE
 
» Interference-Constrained Pricing for D2D Networks
Abstract:
The concept of device-to-device (D2D) communications underlaying cellular networks opens up potential benefits for improving system performance but also brings new challenges, such as interference management. In this paper, we propose a pricing framework for interference management from the D2D users to the cellular system, where the base station (BS) protects itself (or its serving cellular users) by pricing the cross-tier interference caused from the D2D users. A Stackelberg game is formulated to model the interactions between the BS and D2D users. Specifically, the BS sets prices to maximize its revenue (or any desired utility) subject to an interference temperature constraint. For given prices, the D2D users competitively adapt their power allocation strategies for individual utility maximization. We first analyze the competition among the D2D users by noncooperative game theory and an iterative-based distributed power allocation algorithm is proposed. Then, depending on how much network information the BS knows, we develop two optimal algorithms, one for uniform pricing with limited network information and the other for differentiated pricing with global network information. The uniform pricing algorithm can be implemented by a fully distributed manner and requires minimum information exchange between the BS and D2D users, and the differentiated pricing algorithm is partially distributed and requires no iteration between the BS and D2D users. Then, a suboptimal differentiated pricing scheme is proposed to reduce complexity and it can be implemented in a fully distributed fashion. Extensive simulations are conducted to verify the proposed framework and algorithms.
Autors: Yuan Liu;Rui Wang;Zhu Han;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 475 - 486
Publisher: IEEE
 
» Interpreting Temporal Changes of Atmospheric CO2 Over Fire Affected Regions Based on GOSAT Observations
Abstract:
The carbon dioxide (CO2) emissions released from biomass burning significantly affect the temporal variations of atmospheric CO2 concentrations. Based on a long-term (July 2009–June 2015) retrieved data sets by the greenhouse gases observing satellite (GOSAT), the seasonal cycle and interannual variations of column-averaged volume mixing ratios of atmospheric carbon dioxide (XCO2) in four fire affected continental regions were analyzed. The results showed that Northern Africa (NA) had the largest seasonal variations after removing its regional trend of XCO2 with peak-to-peak amplitude of 6.2 ppm within the year, higher than central South America (CSA) (2.4 ppm), Southern Africa (SA) (3.8 ppm), and Australia (1.7 ppm). The detrended regional XCO2 (XCO2) was found to be positively correlated with the fire CO2 emissions during the fire activity period but with different seasonal variabilities. NA recorded the largest change of seasonal variations of XCO2 with a total of 12.8 ppm during fire seasons, higher than CSA, SA, and Australia with 5.4, 6.7, and 2.2 ppm, respectively. During the fire episode, the positive XCO2 was noticed during June–November in CSA, December to next June in NA, and May–November in SA. The Pearson correlation coefficients between the variations of XCO2 and fire CO2 emissions achieved the best correlations in SA ( and ). This letter revealed that fire CO2 emissions and GOSAT XCO2 presented consistent seasonal variations.
Autors: Yusheng Shi;Tsuneo Matsunaga;Hibiki Noda;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jan 2017, volume: 14, issue:1, pages: 77 - 81
Publisher: IEEE
 
» Intra-MARIO: A Fast Mobility Management Protocol for 6LoWPAN
Abstract:
One of the major challenges in 6LoWPAN is to provide continuous services while mobile nodes’ movements with minimizing network inaccessible time caused due to handoffs. Even though MIPv6, HMIPv6, and PMIPv6 are commonly accepted standards to address this in IP networks, they cannot inherently avoid the degradation in communication quality during handoff, since they are not designed with consideration of constrained node networks like 6LoWPAN. In this paper, we propose a new fast mobility management protocol for 6LoWPAN, named intra-MARIO. To minimize handoff delay and enhance service availability, intra-MARIO introduces three important components, which are a fast rejoin scheme for handoff management with an adaptive polling based movement detection and multi-hop pointer forwarding schemes for location management. To justify the effectiveness, we have conducted extensive simulations by comparing intra-MARIO with prior schemes like a basic mobility management scheme and a PMIPv6-based protocol. We then implement intra-MARIO on top of our 6LoWPAN platform (SNAIL) and evaluate the performance of intra-MARIO. The results highlight that intra-MARIO reduces overall handoff delay with low power consumption and minimizes packet losses during handoffs, compared to prior mobility protocols.
Autors: Minkeun Ha;Seong Hoon Kim;Daeyoung Kim;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2017, volume: 16, issue:1, pages: 172 - 184
Publisher: IEEE
 
» Introduction to the January Special Issue on the 2016 IEEE International Solid-State Circuits Conference
Abstract:
The IEEE International Solid-State Circuits Conference (ISSCC) is the premier global forum for presenting advances in solid-state circuits and system-on-a-chip. Every year since its first issue, the IEEE Journal of Solid-State Circuits has highlighted some well-received papers from the most recent ISSCC in special issues. This Special Issue covers the ISSCC Conference held in San Francisco, CA, USA, on February 5–9, 2016.
Autors: Dennis Sylvester;Dejan Marković;Roman Genov;Atsushi Kawasumi;Subhasish Mitra;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jan 2017, volume: 52, issue:1, pages: 3 - 7
Publisher: IEEE
 
» Introduction to the OFC 2016 special issue
Abstract:
The OFC 2016 Special Issue is a collection of outstanding optical networking papers based on OFC 2016 invited papers and the most highly ranked OFC contributed papers. The papers in this special issue cover a broad range of topics including elastic optical networks, network virtualization, software-defined networking, and network optimization.
Autors: Ori Gerstel;Pat Iannone;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Jan 2017, volume: 9, issue:1, pages: OFC1 - OFC1
Publisher: IEEE
 
» Intuitive Formulation of Discontinuous Galerkin Surface Integral Equations for Electromagnetic Scattering Problems
Abstract:
An intuitive formulation of discontinuous Galerkin surface integral equation (DG-SIE) method is proposed in this paper, which is established by performing singularity extraction and singling out the infinitely large term in the entries of the impedance matrices associated with the SIEs, which are popular in solving electromagnetic scattering problems. Nonoverlapping trial and test functions defined on triangles are employed without requirements of the surface current (normal) continuity across their internal boundary contours. The proposed SIE-DG formulation is very flexible and is validated by examples of perfect electrically conducting targets in both conformal and nonconformal meshes.
Autors: Gaobiao Xiao;Yibei Hou;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2017, volume: 65, issue:1, pages: 287 - 294
Publisher: IEEE
 
» Inverse Scattering for Monochromatic Phaseless Measurements
Abstract:
An inverse method and measurement setup for profile and constitutive parameters reconstruction from monochromatic phaseless information is presented. The method is based on the minimization of a cost function that relates the measured field with the one scattered by a model of the object under test (OUT), where the position, contour, and constitutive parameters are the unknowns. As a result, phaseless information is directly related to the inverse problem unknowns, thus avoiding the need of an intermediate phase retrieval step. Due to the nonlinear nature of the cost function, global optimization techniques, such as the particle swarm optimization and differential evolution algorithms, have been considered for cost function minimization. An exhaustive analysis of the cost function behavior as a function of the electric size of the OUT is presented, discussing the optimal OUT size where the proposed methodology provides accurate profile and constitutive parameters reconstruction. The proposed methodology is conceived to use it together with a simple, low-cost measurement setup for fast characterization of perfect electric conductor and dielectric objects. Measurement examples are presented aiming to prove the feasibility of the described measurement setup.
Autors: Yuri Álvarez;María García-Fernández;Lorenzo Poli;Cebrián García-González;Paolo Rocca;Andrea Massa;Fernando Las-Heras;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2017, volume: 66, issue:1, pages: 45 - 60
Publisher: IEEE
 
» Investigating PV Generation Induced Voltage Volatility for Customers Sharing a Distribution Service Transformer
Abstract:
The number of grid-connected rooftop solar photovoltaic (PV) systems is expected to increase significantly in the next few years. Many studies have been conducted on analyzing transmission level voltage stability with high PV penetration, and recent efforts have also analyzed voltage stability at the medium- and low-voltage distribution levels. However, those studies have not considered detailed distribution secondary modeling extending from the primary feeder to the service transformer and all the way through the distribution secondary connections and service drops. This study investigates how variable rooftop solar PV generation impacts voltages at customers sharing a service transformer. Several different types of secondary system topologies are taken into account. A set of rules is presented that can be used to ascertain the level of voltage volatility expected as the solar PV generation varies.
Autors: Abhineet Parchure;Stephen J. Tyler;Melissa A. Peskin;Kaveh Rahimi;Robert P. Broadwater;Murat Dilek;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 71 - 79
Publisher: IEEE
 
» Investigating Surface Loss Effects in Superconducting Transmon Qubits
Abstract:
Superconducting qubits are sensitive to a variety of loss mechanisms including dielectric loss from interfaces. By changing the physical footprint of the qubit, it is possible to modulate sensitivity to surface loss. Here, we show a systematic study of planar superconducting transmons of differing physical footprints to optimize the qubit design for maximum coherence. We find that qubits with small footprints are limited by surface loss and that qubits with large footprints are limited by other loss mechanisms, which are currently not understood.
Autors: Jay M. Gambetta;Conal E. Murray;Y.-K.-K. Fung;Douglas T. McClure;Oliver Dial;William Shanks;Jeffrey W. Sleight;Matthias Steffen;
Appeared in: IEEE Transactions on Applied Superconductivity
Publication date: Jan 2017, volume: 27, issue:1, pages: 1 - 5
Publisher: IEEE
 
» Investigation of a Five-Phase E-Core Hybrid-Excitation Flux-Switching Machine for EV and HEV Applications
Abstract:
In this paper, to improve flux-regulation and constant-power speed range, a 10-stator-pole/18-rotor-pole five-phase hybrid-excitation flux-switching (HEFS) machine with “E”-core stator cell is proposed and analyzed. The topology and operation principle are investigated first. Then, the different armature winding connection methods are evaluated to reduce the total harmonic distortions of phase permanent magnet (PM) flux linkages. Furthermore, based on a simplified magnetic circuit, the analytical power-sizing equations are derived to determine the main design dimensions and parameters of E-core HEFS machines with given performance specifications. The electromagnetic performance, including the conventional static characteristics, such as phase PM flux, back electro-motive-force, cogging torque, electromagnetic torque, and flux-regulation capability, is analyzed by means of two-dimensional (2-D) and 3-D finite-element analysis to take end effect into account. The predicted results indicate that the proposed five-phase E-core HEFS machine exhibits improved flux-regulation capacity and wide range of speed regulation. The performances of HEFS machine are verified by experimental results on a prototype machine. Therefore, the HEFS machine is a promising candidate for electric vehicle and hybrid electric vehicle applications especially for direct-driven systems where the wide range of speed regulation and high-efficiency performance are crucial.
Autors: Wei Hua;Peng Su;Minghao Tong;Jianjian Meng;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 124 - 133
Publisher: IEEE
 
» Investigation of Geometry and Current Density Effects in a Pulsed Electrothermal Plasma Source Using a 2-D Simulation Model
Abstract:
Electrothermal (ET) plasma discharges have application to mass acceleration technologies relevant to military ballistics and magnetic confinement fusion reactor operation. ET plasma discharges are initiated in capillary geometries by passing large currents (order of tens of kiloamperes) along the capillary axis. A partially ionized plasma then forms and radiates heat to the capillary walls inducing ablation. Ablated particles enter the capillary plasma source and cause a pressure surge that can propel pellets to velocities exceeding 2 km/s. These devices present several advantages over other mass accelerator technologies due to their simple design and ability to achieve high projectile launch frequencies. In order to investigate the operation of ET plasma discharges in more detail than previously possible, a 2-D, multifluid model has been developed to simulate the plasma-fluid dynamics that develop in these devices during operation. In this paper, the 2-D simulation model is used to investigate the effect of source geometry and current density on discharge characteristics. Peak pressure and electric field magnitudes for pulsed discharge operation are shown to scale well with theoretical and empirical scaling laws for steady-state discharge operation. The pulse shape of the source internal pressure is shown to change significantly with increasing source radius. The behavior of other plasma parameters is investigated. In addition, observations of the departure from the ablation-controlled arc regime are presented. This analysis suggests that, for the current pulse length investigated, source radii higher than 4 mm require significantly more current density in order to produce sufficient ablation to stabilize the plasma discharge.
Autors: Micah J. Esmond;A. Leigh Winfrey;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2017, volume: 45, issue:1, pages: 121 - 128
Publisher: IEEE
 
» Investigation of Negative Capacitance Gate-all-Around Tunnel FETs Combining Numerical Simulation and Analytical Modeling
Abstract:
A short-channel negative capacitance gate-all-around tunnel field-effect transistor (NC-GAA-TFET) with a ferroelectric gate stack is proposed. Device performance is investigated by integrating three-dimensional (3-D) numerical simulation and the 1D Landau–Khalatnikov equation. It is shown that the NC-GAA-TFET has a steeper subthreshold swing and higher on-state current compared to conventional GAA-TFETs, and demonstrates no hysteretic behavior. Relevant analytical models, including the electrostatic potential model and the shortest tunnel path length (lsp), are developed to explain the device's operating principles and design optimization issues. Results from the analytical electrostatic potential model agree well with those of the numerical simulation. Furthermore, the analytical calculation shows that gate controllability over the channel is enhanced and the lsp value is significantly reduced as the thickness of the ferroelectric dielectric increases, resulting in better device characteristics. These results demonstrate the tremendous potential of NC-GAA-TFETs in low-power applications.
Autors: Chunsheng Jiang;Renrong Liang;Jun Xu;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jan 2017, volume: 16, issue:1, pages: 58 - 67
Publisher: IEEE
 
» Investigation of Nonreciprocal Dispersion Phenomena in Anisotropic Periodic Structures Based on a Curvilinear FDFD Method
Abstract:
The aim of this paper is the investigation of nonreciprocal phenomena in anisotropically loaded 2-D periodic structures. For this purpose, our well-established 2-D curvilinear finite difference frequency domain method is combined with periodic boundary conditions and extended toward the eigenanalysis of periodic structures loaded with both isotropic and general anisotropic materials. The periodic structures are simulated in a 2-D domain, while uniformity is considered along the third axis. The propagation constant along the third axis can either be zero (in-plane-propagation) or nonzero (out-of-plane propagation). Particular effort was devoted to the identification of the appropriate irreducible Brillouin zone to be scanned during the eigenanalysis. It was herein realized that similar to geometrically artificial crystal anisotropy, the wave propagation directional asymmetries modify the irreducible Brillouin zone in the microwave regime as well. Both gyrotropic and particularly magnetized ferrite as well as full tensor anisotropic (arbitrarily biased ferrite) material loadings are investigated through the eigenanalysis of different periodic structures, including strip grating. Interesting nonreciprocal backward wave and unidirectional phenomena are justified as expected.
Autors: Panagiotis C. Theofanopoulos;Christos S. Lavranos;Kyriakos E. Zoiros;Georgios C. Trichopoulos;Gérard Granet;George A. Kyriacou;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2017, volume: 65, issue:1, pages: 36 - 49
Publisher: IEEE
 
» Investigation of the p-GaN Gate Breakdown in Forward-Biased GaN-Based Power HEMTs
Abstract:
In this letter, we report a detailed experimental investigation of the time-dependent breakdown induced by forward gate stress in GaN-based power HEMTs with a p-type gate, controlled by a Schottky metal/p-GaN junction. When a high stress voltage is applied on the gate, a large voltage drop and an electric field occur in the depletion region of the p-GaN close to the metal interface, promoting the formation of a percolation path. We have investigated the mechanisms underlying the gate breakdown by adopting different stress conditions, analyzing the influence of the temperature, and investigating the activation energy of the traps. In addition, thanks to this approach, the device lifetime has been evaluated and an original empirical model, representing the relationship between the gate leakage current and the time to failure, has been proposed.
Autors: Andrea Natale Tallarico;Steve Stoffels;Paolo Magnone;Niels Posthuma;Enrico Sangiorgi;Stefaan Decoutere;Claudio Fiegna;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2017, volume: 38, issue:1, pages: 99 - 102
Publisher: IEEE
 
» Investigations of Near Miss Incidents—New Facility Construction and Commissioning Activities
Abstract:
Multiple electrical incidents occurred during construction and commissioning activities at a new production facility. This paper describes the investigations and findings while highlighting similarities between the incidents, designing for safety, and management of electrical safety during the transfer of construction to commissioning activities.
Autors: Josh D. Popp;Mark S. Scarborough;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 615 - 621
Publisher: IEEE
 
» Investigations on Optimal Pulse Width Modulation to Minimize Total Harmonic Distortion in the Line Current
Abstract:
High-power and high-speed motor drives have only a few switching transitions in each line cycle. Pulse width modulation (PWM) waveforms with positive voltage transition at the positive zero crossing of the fundamental voltage (type-A) are generally considered for PWM waveform with an even number of switching angles per quarter, whereas waveforms with negative voltage transition at the positive zero crossing (type-B) are considered for an odd number of switching angles per quarter. Optimal switching angles to minimize the total harmonic distortion (THD) in motor current are reported for both type-A and type-B waveforms of pulse numbers () of 5, 7, 9, and 11. Based on simulation and experimental studies on a kW induction motor (IM) drive, optimal type-A and type-B PWM methods are shown to be better than each other in different modulation ranges for each pulse number. The space vector based analysis of optimal type-A and type-B waveforms brings out the optimal vector sequence at any modulation index for a given . Findings of the space vector based analysis lead to a new approach for determining optimal switching angles with much reduced computational effort. Compared to sine-triangle PWM, deployment of optimal vector sequences in an IM drive, having a maximum switching frequency of 250 Hz, leads to significant reduction in both THD of line current as well as motor losses over a wide range of speeds and load conditions.
Autors: Avanish Tripathi;G. Narayanan;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2017, volume: 53, issue:1, pages: 212 - 221
Publisher: IEEE
 
» Iso-Trapping Measurement Technique for Characterization of Self-Heating in a GaN HEMT
Abstract:
The temperature response of field-effect transistors (FETs) to instantaneous power dissipation has been shown to be significant at high frequencies, even though the self-heating process has a very slow time constant. This affects intermodulation at high frequencies. A major difficulty in characterizing the self-heating process in microwave FETs is to differentiate between the self-heating and charge-trapping rates. An iso-trapping measurement technique is proposed by which it becomes possible to characterize the self-heating process in an FET in isolation from the effect of the charge-trapping process in the FET. The results of iso-trapping measurements performed on a GaN high-electron-mobility transistor are presented, and used to successfully characterize the self-heating process.
Autors: Sayed Ali Albahrani;Anthony Parker;Michael Heimlich;Bryan Schwitter;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2017, volume: 64, issue:1, pages: 102 - 108
Publisher: IEEE
 
» Iterative Control for Networked Heterogeneous Multi-Agent Systems With Uncertainties
Abstract:
This note addresses the convergence of iterative control for networked, heterogeneous, multi-agent systems, where each agent has potentially different dynamics and dissimilar uncertainties. The major contribution of this work is to quantify the acceptable modeling uncertainty for ensuring convergence of the proposed iterative approach for collaborative tracking. Convergence conditions are established for the case when inversion-based iterative control of each individual agent (designed separately, independent of the iterative controllers of the other agents) are conjoined using a network graph structure.
Autors: Santosh Devasia;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2017, volume: 62, issue:1, pages: 431 - 437
Publisher: IEEE
 
» IZDPWM-Based Feedforward Controller for Grid-Connected Inverters Under Unbalanced and Distorted Conditions
Abstract:
In grid-connected inverters, a feedforward controller accurately compensates for a large number of the harmonic components of the injected current. This controller is fast and directly tackles the grid dynamic voltage disturbances without doing any further harmonic analysis. A feedforward controller was introduced to a three-phase grid connection with a wye configuration; however, for the widespread delta connections, such a scheme is less established. Moreover, the nonsinusoidal profile of the grid voltage waveform makes the online conversion of line-to-line values into phase values impossible. In this paper, implicit zero-sequence discontinuous pulse width modulation (IZDPWM) based feedforward control is implemented on the two-level grid-connected inverter. Regardless of the grid topology, the IZDPWM-based controller ensures sinusoidal current injection to the grid under balanced, unbalanced, and distorted conditions.
Autors: Alireza Shayestehfard;Saad Mekhilef;Hazlie Mokhlis;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Jan 2017, volume: 64, issue:1, pages: 14 - 21
Publisher: IEEE
 
» Jacques arsene d’arsonval: his life and contributions to electrical instrumentation in physics and medicine. part ii: communications equipment and electrical measuring instruments [scanning our past]
Abstract:
In 1877, d’Arsonval examined the possibilities for using the recently invented telephone in his studies on the electrical properties of muscle contraction. The telephone seemed at first to be a mere improvement on the telegraph, until alternative uses, including those intended to improve health, well-being, safety, or security, were discovered. Physicians were among the first to employ telephones as conversational instruments, but they also thought about the potential of these instruments to be used in medical practice as diagnostic tools. However, when applying it to the chest of a healthy person, no sounds—whether of breathing, voice, or cough —could be heard; it was clear that sounds could be heard just as well, or better, through the stethoscope [1].
Autors: Simón Reif-Acherman;
Appeared in: Proceedings of the IEEE
Publication date: Jan 2017, volume: 105, issue:1, pages: 167 - 175
Publisher: IEEE
 
» Joint MR-PET Reconstruction Using a Multi-Channel Image Regularizer
Abstract:
While current state of the art MR-PET scanners enable simultaneous MR and PET measurements, the acquired data sets are still usually reconstructed separately. We propose a new multi-modality reconstruction framework using second order Total Generalized Variation (TGV) as a dedicated multi-channel regularization functional that jointly reconstructs images from both modalities. In this way, information about the underlying anatomy is shared during the image reconstruction process while unique differences are preserved. Results from numerical simulations and in-vivo experiments using a range of accelerated MR acquisitions and different MR image contrasts demonstrate improved PET image quality, resolution, and quantitative accuracy.
Autors: Florian Knoll;Martin Holler;Thomas Koesters;Ricardo Otazo;Kristian Bredies;Daniel K Sodickson;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2017, volume: 36, issue:1, pages: 1 - 16
Publisher: IEEE
 
» Joint multi-layer survivability techniques for IP-over-elastic-optical- networks
Abstract:
The traffic in metro and core networks is forecasted to grow in volume but also in dynamicity. Network operators dimension their optical networks and their IP edges for the expected traffic peak, and also reserve additional resources for the required survivability level. The latter is typically done by protection mechanisms at the optical or IP layer only. Multi-layer proactive restoration techniques can reduce the cost by enabling resource sharing while providing the same level of survivability. In this work we formulate the multi-layer survivability problem for an IP-over-elastic-optical-network and present ILP formulations to solve it, targeting two survivability levels: (i) single optical link and (ii) single optical link or optical and IP node failure. The proposed ILP algorithms are also distinguished with respect to their failure consideration point: (i) sequential, where we assume that the network is dimensioned for normal operation and then re-dimensioned to be resilient, and (ii) joint, where the network is dimensioned in a single step, considering normal and all single failure operation. We exploit the proactive (a priori provisioning) restoration concept to achieve sharing of the backup resources among different failure states. The proposed multi-layer techniques enable even higher efficiency, exploiting the IP grooming capabilities to enable the sharing of backup resources for a specific failure state but also the sharing of primary and backup resources. Compared to traditional single-layer protection approaches, the proposed joint multi-layer techniques were shown to yield significant cost savings.
Autors: P. Papanikolaou;K. Christodoulopoulos;E. Varvarigos;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Jan 2017, volume: 9, issue:1, pages: A85 - A98
Publisher: IEEE
 
» Joint Multiple Symbol Differential Detection and Channel Decoding for Noncoherent UWB Impulse Radio by Belief Propagation
Abstract:
This paper proposes a belief propagation (BP) message passing algorithm-based joint multiple symbol differential detection (MSDD) and channel decoding scheme for noncoherent differential ultra-wideband impulse radio (UWB-IR) systems. MSDD is an effective means to improving the performance of noncoherent differential UWB-IR systems. To optimize the overall detection and decoding performance, this paper proposes a novel soft-in soft-out (SISO) MSDD scheme for noncoherent differential UWB-IR. We first propose a new sampling mechanism for the noncoherent auto-correlation receiver to sample the received UWB-IR signal. The proposed sampling mechanism can exploit the dependences (imposed by the differential modulation) among data symbols throughout the whole packet. The signal probabilistic model has a hidden Markov chain structure. We use a factor graph to represent this hidden Markov chain. Then, we apply BP message passing algorithm on the factor graph to develop an SISO MSDD scheme, which is easy to integrate with SISO channel decoding to form a joint MSDD and channel decoding scheme. Performance results of bit error rate simulations and EXIT chart analyses indicate the performance advantages of our scheme over the previous MSDD scheme.
Autors: Taotao Wang;Tiejun Lv;Hui Gao;Shengli Zhang;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 293 - 306
Publisher: IEEE
 
» Joint Multiuser Detection of Multidimensional Constellations Over Fading Channels
Abstract:
We investigate the error performance of multidimensional constellations in the multiple access and broadcast channels. More specifically, we provide closed-form expressions for the pairwise error probability (PEP) of the joint maximum likelihood detection, for multiuser signaling in the presence of additive white Gaussian noise and Rayleigh fading. Arbitrary numbers of users and multidimensional signal sets are assumed, while the provided formula for the PEP is a function of the dimension-wise distances of the multidimensional constellation. Furthermore, a useful upper bound on the average symbol error probability is also obtained through the union bound. The analysis is applied to the sparse code multiple access systems. The analytical results are validated successfully through simulations, and show their importance in the multidimensional constellation design.
Autors: Jinchen Bao;Zheng Ma;George K. Karagiannidis;Ming Xiao;Zhongliang Zhu;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2017, volume: 65, issue:1, pages: 161 - 172
Publisher: IEEE
 
» Joint Optimal Transmission Power and Sensing Time for Energy Efficient Spectrum Sensing in Cognitive Radio System
Abstract:
Joint optimal transmission power and sensing time of energy efficient spectrum sensing for a cognitive radio (CR) system is considered. The design problem is formulated as a function of two variables subjected to primary user protection constraints. An iterative algorithm with low computational complexity is proposed to determine the joint optimal transmission power and sensing time that maximizes the energy efficiency for a single CR system. Simulation results of the proposed algorithm are provided, evaluated, and compared with those of existing algorithms.
Autors: Faroq Awin;Esam Abdel-Raheem;Majid Ahmadi;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2017, volume: 17, issue:2, pages: 369 - 376
Publisher: IEEE
 
» Joint Turbo Decoding for Overloaded MIMO-OFDM Systems
Abstract:
To achieve an excellent error-correcting capability, the Third-Generation Partnership Project (3GPP) Long-Term Evolution (LTE) employs turbo codes as its forward error correction (FEC) standard. In addition, to achieve higher throughput, the LTE also implements multiple-input–multiple-output (MIMO) systems. Although a conventional turbo decoding scheme gives satisfactory performance in ideal MIMO systems, significant performance degradation occurs in an overloaded MIMO system when the number of transmit antennas is larger than that of receive antennas. In this paper, a joint decoding scheme for turbo codes, i.e., so-called joint turbo decoding, is proposed. In joint turbo decoding, calculations of soft information are conducted for each combination of bits from all streams instead of separately between each stream. In addition, to combine the trellis diagrams from all the streams, a super-trellis diagram is employed. The numerical results obtained through computer simulation show that the proposed scheme performs better than the conventional scheme, particularly in the case of an overloaded MIMO system. In the MIMO system with four transmit and two receive antennas, up to 2-dB performance enhancement can be attained at a bit error rate (BER) of 10−5. The proposed scheme also obtains improved throughput with a throughput/(SNR/stream) ratio close to the theoretical capacity of overloaded MIMO systems.
Autors: Ilmiawan Shubhi;Yukitoshi Sanada;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 433 - 442
Publisher: IEEE
 
» Kalman Filtered Bio Heat Transfer Model Based Self-adaptive Hybrid Magnetic Resonance Thermometry
Abstract:
To develop a self-adaptive and fast thermometry method by combining the original hybrid magnetic resonance thermometry method and the bio heat transfer equation (BHTE) model. The proposed Kalman filtered Bio Heat Transfer Model Based Self-adaptive Hybrid Magnetic Resonance Thermometry, abbreviated as KalBHT hybrid method, introduced the BHTE model to synthesize a window on the regularization term of the hybrid algorithm, which leads to a self-adaptive regularization both spatially and temporally with change of temperature. Further, to decrease the sensitivity to accuracy of the BHTE model, Kalman filter is utilized to update the window at each iteration time. To investigate the effect of the proposed model, computer heating simulation, phantom microwave heating experiment and dynamic in-vivo model validation of liver and thoracic tumor were conducted in this study. The heating simulation indicates that the KalBHT hybrid algorithm achieves more accurate results without adjusting to a proper value in comparison to the hybrid algorithm. The results of the phantom heating experiment illustrate that the proposed model is able to follow temperature changes in the presence of motion and the temperature estimated also shows less noise in the background and surrounding the hot spot. The dynamic in-vivo model validation with heating simulation demonstrates that the proposed model has a higher convergence rate, more robustness to susceptibility problem surrounding the hot spot and more accuracy of temperature estimation. In the healthy liver experiment with heating simulation, the RMSE of the hot spot of the proposed model is reduced to about 50% compared to the RMSE of the original hybrid model and the convergence time becomes only about one fifth of the hybrid model. The proposed model is able to improve the accuracy of the original hybrid algorithm and accelerate the co- vergence rate of MR temperature estimation.
Autors: Yuxin Zhang;Shuo Chen;Kexin Deng;Bingyao Chen;Xing Wei;Jiafei Yang;Shi Wang;Kui Ying;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2017, volume: 36, issue:1, pages: 194 - 202
Publisher: IEEE
 
» Key Abstractions for IoT-Oriented Software Engineering
Abstract:
Despite the progress in Internet of Things (IoT) research, a general software engineering approach for systematic development of IoT systems and applications is still missing. A synthesis of the state of the art in the area can help frame the key abstractions related to such development. Such a framework could be the basis for guidelines for IoT-oriented software engineering.
Autors: Franco Zambonelli;
Appeared in: IEEE Software
Publication date: Jan 2017, volume: 34, issue:1, pages: 38 - 45
Publisher: IEEE
 
» Kief Morris on Infrastructure as Code
Abstract:
Cloud specialist Kief Morris joins Software Engineering Radio host Sven Johann to discuss the benefits of infrastructure as code, including security, auditability, testing, documentation, and traceability.
Autors: Sven Johann;
Appeared in: IEEE Software
Publication date: Jan 2017, volume: 34, issue:1, pages: 117 - 120
Publisher: IEEE
 
» KKCV-GA-Based Method for Optimal Analog Test Point Selection
Abstract:
A novel diagnosis oriented method for optimal analog test point selection is proposed. The method uses a kernel density estimation on -nearest neighbors-based cross-validation to evaluate the diagnostic capability of the selected test points, and then employs a genetic algorithm to search the quasi-optimal solution with the maximum diagnostic capability under a limited number of test points. Experimental results show that better solutions in terms of the diagnostic accuracies of the advanced intelligent classifiers can be obtained, and the knowledge of critical test points is revealed, which supports further improvement of the optimization, not only to increase the probability of reaching the global optimal solutions but also to reduce the time costs. In addition, with the precise estimation of the diagnostic capability, the proposed method can also be used to verify the results produced by other methods in this field.
Autors: Xiaofeng Tang;Aiqiang Xu;Shuangcheng Niu;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2017, volume: 66, issue:1, pages: 24 - 32
Publisher: IEEE
 
» Knowledge-Enhanced Mobile Video Broadcasting Framework With Cloud Support
Abstract:
The convergence of mobile communications and cloud computing facilitates the cross-layer network design and content-assisted communication. Mobile video broadcasting can benefit from this trend by utilizing joint source-channel coding and strong information correlation in clouds. In this paper, a knowledge-enhanced mobile video broadcasting (KMV-Cast) is proposed. The KMV-Cast is built on a linear video transmission instead of a traditional digital video system, and exploits the hierarchical Bayesian model to integrate the correlated information into the video reconstruction at the receiver. The correlated information is distilled to obtain its intrinsic features, and the Bayesian estimation algorithm is used to maximize the video quality. The KMV-Cast system consists of both likelihood broadcasting and prior knowledge broadcasting. The simulation results show that the proposed KMV-Cast scheme outperforms the typical linear video transmission scheme called Softcast, and achieves 8 dB more of the peak signal-to-noise ratio (PSNR) gain at low-SNR channels (i.e., −10 dB), and 5 dB more of PSNR gain at high-SNR channels (i.e., 25 dB). Compared with the traditional digital video system, the proposed scheme has 7 dB more of PSNR gain than the JPEG2000 + 802.11a scheme at a 10-dB channel SNR.
Autors: Xin-Lin Huang;Jun Wu;Fei Hu;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jan 2017, volume: 27, issue:1, pages: 6 - 18
Publisher: IEEE
 
» LaSalle-Type Theorem and Its Applications to Infinite Horizon Optimal Control of Discrete-Time Nonlinear Stochastic Systems
Abstract:
Based on discrete martingale theory, the LaSalle-type theorem for general discrete-time stochastic systems is obtained and the almost sure stability is in turn discussed. As applications, infinite horizon nonlinear optimal regulator is investigated, and a dynamical programming equation called the Hamilton-Jacobi-Bellman equation is also derived for discrete-time nonlinear stochastic optimal control.
Autors: Weihai Zhang;Xiangyun Lin;Bor-Sen Chen;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2017, volume: 62, issue:1, pages: 250 - 261
Publisher: IEEE
 
» Lawn care for the lazy [Past Forward]
Abstract:
The most miraculous thing at the 1960 Miracle Garden Exhibition in Paris had to be the H.C. Webb & Co. radio-controlled electric lawn mower. The machine, which ran off an electric motor powered by two 12-volt car batteries, was by all accounts quite successful. Somehow, though, it failed to inspire a new era of sedentary lawn care, much to the disappointment of suburban teenagers everywhere.
Autors: Evan Ackerman;
Appeared in: IEEE Spectrum
Publication date: Jan 2017, volume: 54, issue:1, pages: 64 - 64
Publisher: IEEE
 
» Layered Constructions for Low-Delay Streaming Codes
Abstract:
We study error correction codes for multimedia streaming applications where a stream of source packets must be transmitted in real-time, with in-order decoding, and strict delay constraints. In our setup, the encoder observes a stream of source packets in a sequential fashion, and channel packets must be transmitted between the arrival of successive source packets. Each channel packet can depend on all the source packets observed up to and including that time, but not on any future source packets. The decoder must reconstruct the source stream with a delay of packets. We consider a class of packet erasure channels with burst and isolated erasures, where the erasure patterns are locally constrained. Our proposed model provides a tractable approximation to statistical models, such as the Gilbert–Elliott channel, for capacity analysis. When , i.e., when the source-packet arrival and channel-packet transmission rates are equal, we establish upper and lower bounds on the capacity, that are within one unit of the decoding delay . We also establish necessary and sufficient conditions on the column distance and column span of a convolutional code to be feasible, and in turn establish a fundamental tradeoff between these. Our proposed codes—maximum distance and span codes—achieve a near-optimal tradeoff between the column distance and column span, and involve a layered construction. When , we establish the capacity for the burst-erasure channel and an achievable rate in the general case. Extensive numerical simulations o er Gilbert–Elliott and Fritchman channel models suggest that our codes also achieve significant gains in the residual loss probability over statistical channel models.
Autors: Ahmed Badr;Pratik Patil;Ashish Khisti;Wai-Tian Tan;John Apostolopoulos;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2017, volume: 63, issue:1, pages: 111 - 141
Publisher: IEEE
 
» Layered Space Shift Keying Modulation Over MIMO Channels
Abstract:
Space shift keying (SSK) modulation is an emerging transmission technique for multiple-input multiple-output (MIMO) wireless channels, which exploits the spatial domain to convey information. In this paper, we present a layered space shift keying (LSSK) modulation scheme to fully exploit the spatial domain to transmit information bits, where a layered architecture is developed to achieve spatial multiplexing transmission in an SSK system. Specifically, LSSK leverages the rotated signals predetermined at the transceiver to identify different layers and improve the bit-error-rate (BER) performance. The layered signals are directly generated by the proposed LSSK modulation method with a low computational overhead. Furthermore, we propose a layered-and-joint (LJ) near-optimal detection algorithm based on the layered architecture of LSSK to reduce the detection complexity. In LJ detection, layered detection is performed to find a set of detection candidates for each layer, and then, joint detection is performed with these candidates. We show that the performance of LJ detection is quite close to that of optimal maximum-likelihood detection with significantly reduced detection complexity for high-spectrum-efficiency scenarios. Results demonstrate that the proposed LSSK scheme substantially improves the spectrum efficiency of an SSK system and outperforms other existing MIMO schemes.
Autors: Shu Fang;Lei Li;Su Hu;Jianhua Tang;Zongdi Yue;Gang Feng;Ashish Pandharipande;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2017, volume: 66, issue:1, pages: 159 - 174
Publisher: IEEE
 
» Layman Analytics System: A Cloud-Enabled System for Data Analytics Workflow Recommendation
Abstract:
In today’s big data era, there is a tremendously huge amount of data available. Layman users lack not only the knowledge and experience in data analytics to make sense of these data but also the computational resources for executing the analytics. In this paper, we propose and develop a layman analytics system (LAS), which provides the layman users with a scalable and ready-to-use analytics tool to automatically generate analytics workflows for classification tasks. The LAS is designed to benefit from existing open-source data analytics tools using generic ontological modeling of analytics operators from these tools as well as adaptive constraint refinement for metadata learning. Moreover, the LAS can be deployed on both public and private clouds to cater to the need of scalable computing and easy maintenance. To demonstrate the performance of the LAS, we conducted experiments with 114 data sets obtained from the University of California Irvine Machine Learning Repository. The workflows generated by the LAS were benchmarked against the OpenML whereby each data set has a range of classification accuracy obtained using classifiers designed and fine-tuned by data experts. The comparisons showed that 87 out of 114 data sets have exceeded the 50th percentile of the benchmark data. Among these 87 data sets, the LAS outperforms the 90th percentile of the benchmarks on 49 data sets.
Autors: Theint Theint Aye;Gary Kee Khoon Lee;Yi Su;Tianyou Zhang;Chonho Lee;Henry Kasim;Ivan Hoe;Francis Bu-Sung Lee;Terence Gih Guang Hung;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2017, volume: 14, issue:1, pages: 160 - 170
Publisher: IEEE
 
» Layout Symmetries: Quantification and Application to Cancel Nonlinear Process Gradients
Abstract:
This paper presents criteria, using simple integer arithmetic, to determine if a layout of a pair of devices broken into multiple, identical sections cancels the effect of nonlinear process gradients. These criteria allow quantification of 12 layout symmetries that can be leveraged to cancel specific process gradient components. “Dispersion,” the degree to which device segments are distributed throughout a layout, is also quantified in a simple and intuitive way, and used to identify which of multiple gradient canceling layouts is best. Techniques to construct maximally dispersive quadratic gradient canceling layouts with arbitrary numbers of rows and columns are presented.
Autors: Colin C. McAndrew;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jan 2017, volume: 36, issue:1, pages: 1 - 14
Publisher: IEEE
 
» LazyCtrl: A Scalable Hybrid Network Control Plane Design for Cloud Data Centers
Abstract:
The advent of software defined networking enables flexible, reliable and feature-rich control planes for data center networks. However, the tight coupling of centralized control and complete visibility leads to a wide range of issues among which scalability has risen to prominence due to the excessive workload on the central controller. By analyzing the traffic patterns from a couple of production data centers, we observe that data center traffic is usually highly skewed and thus edge switches can be clustered into a set of communication-intensive groups according to traffic locality. Motivated by this observation, we present LazyCtrl, a novel hybrid control plane design for data center networks where network control is carried out by distributed control mechanisms inside independent groups of switches while complemented with a global controller. LazyCtrl aims at bringing laziness to the global controller by dynamically devolving most of the control tasks to independent switch groups to process frequent intra-group events near the datapath while handling rare inter-group or other specified events by the controller. We implement LazyCtrl and build a prototype based on Open vSwitch and Floodlight. Trace-driven experiments on our prototype show that an effective switch grouping is easy to maintain in multi-tenant clouds and the central controller can be significantly shielded by staying “lazy”, with its workload reduced by up to 82 percent.
Autors: Kai Zheng;Lin Wang;Baohua Yang;Yi Sun;Steve Uhlig;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jan 2017, volume: 28, issue:1, pages: 115 - 127
Publisher: IEEE
 
» LBP-Structure Optimization With Symmetry and Uniformity Regularizations for Scene Classification
Abstract:
Local binary pattern (LBP) and its variants have been widely used in many visual recognition tasks. Most existing approaches utilize predefined LBP structures to extract LBP features. Recently, data-driven LBP structures have shown promising results. However, due to the limited number of training samples, data-driven structures may overfit the training samples, hence could not generalize well on the novel testing samples. To address this problem, we propose two structural regularization constraints for LBP-structure optimization: symmetry constraint and uniformity constraint. These two constraints are inspired by predefined LBP structures, which convey the human prior knowledge on designing LBP structures. The LBP-structure optimization is casted as a binary quadratic programming problem and solved efficiently via the branch-and-bound algorithm. The evaluation on two scene-classification datasets demonstrates the superior performance of the proposed approach compared with both predefined LBP structures and unconstrained data-driven LBP structures.
Autors: Jianfeng Ren;Xudong Jiang;Junsong Yuan;
Appeared in: IEEE Signal Processing Letters
Publication date: Jan 2017, volume: 24, issue:1, pages: 37 - 41
Publisher: IEEE
 
» Leaky Buffer: A Novel Abstraction for Relieving Memory Pressure from Cluster Data Processing Frameworks
Abstract:
The shift to the in-memory data processing paradigm has had a major influence on the development of cluster data processing frameworks. Numerous frameworks from the industry, open source community and academia are adopting the in-memory paradigm to achieve functionalities and performance breakthroughs. However, despite the advantages of these in-memory frameworks, in practice they are susceptible to memory-pressure related performance collapse and failures. The contributions of this paper are two-fold. First, we conduct a detailed diagnosis of the memory pressure problem and identify three preconditions for the performance collapse. These preconditions not only explain the problem but also shed light on the possible solution strategies. Second, we propose a novel programming abstraction called the leaky buffer that eliminates one of the preconditions, thereby addressing the underlying problem. We have implemented a leaky buffer enabled hashtable in Spark, and we believe it is also able to substitute the hashtable that performs similar hash aggregation operations in any other programs or data processing frameworks. Experiments on a range of memory intensive aggregation operations show that the leaky buffer abstraction can drastically reduce the occurrence of memory-related failures, improve performance by up to 507 percent and reduce memory usage by up to 87.5 percent.
Autors: Zhaolei Liu;T. S. Eugene Ng;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jan 2017, volume: 28, issue:1, pages: 128 - 140
Publisher: IEEE
 
» Learning Bayesian Network Structures to Augment Aircraft Diagnostic Reference Models
Abstract:
Fault detection and isolation schemes are designed to detect the onset of adverse events during operations of complex systems, such as aircraft and industrial processes. The state-of-the-art fault diagnosis systems on aircraft combine an expert-created reference model of the associations between faults and symptoms, and a Naïve Bayes reasoner. For complex systems with many dependencies between components, the expert-generated reference models are often incomplete, which hinders timely and accurate fault diagnosis. Mining aircraft flight data is a promising approach to finding these missing relations between symptoms and data. However, mining algorithms generate a multitude of relations, and only a small subset of these relations may be useful for improving diagnoser performance. In this paper, we adopt a knowledge engineering approach that combines data mining methods with human expert input to update an existing reference model and improve the overall diagnostic performance. We discuss three case studies to demonstrate the effectiveness of this method.
Autors: Daniel L. C. Mack;Gautam Biswas;Xenofon D. Koutsoukos;Dinkar Mylaraswamy;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2017, volume: 14, issue:1, pages: 358 - 369
Publisher: IEEE
 
» Let There Be Light—Optoprobes for Neural Implants
Abstract:
Over the past decades, optical technologies have entered neural implant technologies. Applications such as optogenetics, near-infrared spectroscopy (NIRS), and direct-near-infrared stimulation (NIS) request technical devices that combine electrical and optical recording as well as stimulation capabilities using light sources and/or optical sensors. Optoprobes are the technical devices that meet these requirements. This paper provides basic insights into optogenetic mechanisms, the background of NIRS and NIS, and focuses on fundamental requirements of technical systems from a biological background. The state of the art of optoprobes is reviewed and attention is drawn on the potential long-term stability of these technical devices for chronic neural implants. Further, material selection for stiff and flexible devices, applicable light sources, waveguide and coupling concepts, packaging paradigms as well as system assembly and integration aspects are discussed in view of biocompatible and biostable devices. This paper also considers the physical background of light scattering and heat generation when light sources are implanted into biological tissue.
Autors: Marie T. Alt;Eva Fiedler;Linda Rudmann;Juan S. Ordonez;Patrick Ruther;Thomas Stieglitz;
Appeared in: Proceedings of the IEEE
Publication date: Jan 2017, volume: 105, issue:1, pages: 101 - 138
Publisher: IEEE
 
» Leveraging Social Communities for Optimizing Cellular Device-to-Device Communications
Abstract:
Device-to-device (D2D) communications over the licensed wireless spectrum has been recently proposed as a promising technology to meet the capacity crunch of next generation cellular networks. However, due to the high mobility of cellular devices, establishing and ensuring the success of D2D transmission become a major challenge. To this end, in this paper, a novel framework is proposed to enable devices to form multi-hop D2D connections in an effort to maintain sustainable communication in the presence of device mobility. To solve the problem posed by device mobility, in contrast to existing works, which mostly focus on physical domain information, a durable community-based approach is introduced taking social encounters into context. It is shown that the proposed scheme can derive an optimal solution for time sensitive content transmission while also minimizing the cost that the base station pays in order to incentivize users to participate in D2D. Simulation results show that the proposed social community aware approach yields significant performance gain, in terms of the amount of traffic offloaded from the cellular network to the D2D tier, compared with the classical social-unaware methods.
Autors: Md Abdul Alim;Tianyi Pan;My T. Thai;Walid Saad;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2017, volume: 16, issue:1, pages: 551 - 564
Publisher: IEEE
 
» LiDAR Data Filtering and DTM Generation Using Empirical Mode Decomposition
Abstract:
LiDAR technology is advancing. As a result, researchers can benefit from high-resolution height data from Earth’s surface. Digital terrain model (DTM) generation and point classification (filtering) are two important problems for LiDAR data. These are connected problems since solving one helps solving the other. Manual classification of LiDAR point data could be time consuming and prone to errors. Hence, it would not be feasible. Therefore, researchers proposed several methods to solve DTM generation and point classification problems. Although these methods work fairly well in most cases, they may not be effective for all scenarios. To contribute in this research topic, a novel method based on two-dimensional (2-D) empirical mode decomposition (EMD) is proposed in this study. Local, nonlinear, and nonstationary characteristics of EMD allow better DTM generation. The proposed method is tested on two publicly available LiDAR dataset, and promising results are obtained. Besides, the proposed method is compared with other methods in the literature. Comparison results indicate that the proposed method has certain advantages in terms of performance.
Autors: Abdullah H. Özcan;Cem Ünsalan;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2017, volume: 10, issue:1, pages: 360 - 371
Publisher: IEEE
 
» Limitations of Highly-Available Eventually-Consistent Data Stores
Abstract:
Modern replicated data stores aim to provide high availability, by immediately responding to client requests, often by implementing objects that expose concurrency. Such objects, for example, multi-valued registers (MVRs), do not have sequential specifications. This paper explores a recent model for replicated data stores that can be used to precisely specify causal consistency for such objects, and liveness properties like eventual consistency, without revealing details of the underlying implementation. The model is used to prove the following results: 1) An eventually consistent data store implementing MVRs cannot satisfy a consistency model strictly stronger than observable causal consistency (). is a model somewhat stronger than causal consistency, which captures executions in which client observations can use causality to infer concurrency of operations. This result holds under certain assumptions about the data store. 2) Under the same assumptions, an eventually consistent and causally consistent replicated data store must send messages of size linear in the size of the system: If objects, each -bit in size, are supported by replicas, then there is an execution in which an -bit message is sent.
Autors: Hagit Attiya;Faith Ellen;Adam Morrison;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jan 2017, volume: 28, issue:1, pages: 141 - 155
Publisher: IEEE
 

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