Electrical and Electronics Engineering publications abstract of: 02-2018 sorted by title, page: 7

» Distributed Scheduling in Multiple Access With Bursty Arrivals Under a Maximum Delay Constraint
Abstract:
A time-slotted multiple access system with bursty data arrivals to the terminals is considered, where variable sized packets independently arrive in each slot at every transmitter. Each packet is required to be delivered to a common receiver within a certain number of slots specified by a maximum delay constraint. The terminals know only their own packet arrival process, i.e., the arrivals at the rest of the terminals are unknown to each transmitter, except for their probability distributions. For this interesting distributed multiple access model, we design novel online communication schemes which transport the arriving data without any outage, while respecting the delay constraint. In particular, the users choose their respective transmit powers in a distributed manner, ensuring at the same time that the joint power vector is sufficient to support the distributed choice of data rates employed in that slot. The proposed schemes are not only optimal in minimizing the average transmit sum power, but they also considerably outperform conventional orthogonal multiple access techniques like time-division multiple access. An optimal scheme for a multiple access channel with arrivals and time-varying fading is also presented, under a unit slot delay constraint.
Autors: Sakshi Kapoor;Sreejith Sreekumar;Sibi Raj B. Pillai;
Appeared in: IEEE Transactions on Information Theory
Publication date: Feb 2018, volume: 64, issue:2, pages: 1297 - 1316
Publisher: IEEE
 
» Distributed TOA-Based Positioning in Wireless Sensor Networks: A Potential Game Approach
Abstract:
In this letter, we solve the problem of positioning based on the time-of-arrival technique in wireless sensor networks. Different from the traditional estimation methods, the position of a target node is considered as a strategy of anchor nodes, and the cognition information is introduced to enrich positional information. After proposing the concept of consensus of cognition and consensus of measurements, we re-investigate the positioning problem from a game-theoretic perspective. It is proved that the proposed game is an exact potential game, which exhibits attractive properties about the Nash equilibrium (NE). Then, the best response algorithm is used to achieve the NE point. The simulation results indicate that the performance of positioning with a suitable tradeoff parameter is better than the performance of recursive least-squares algorithm in terms of positional accuracy and convergence rate.
Autors: Mingxing Ke;Yuhua Xu;Alagan Anpalagan;Dianxiong Liu;Yuli Zhang;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 316 - 319
Publisher: IEEE
 
» DIY for Engineers [MicroBusiness]
Abstract:
DIY is the abbreviation for “do it yourself.” I recently had a friend comment to me, “You do everything yourself.” That's not really true, but it's in my nature to want to do things myself. I suspect it's that way for many engineers; we chose engineering because we like to make things.
Autors: Fred Schindler;
Appeared in: IEEE Microwave Magazine
Publication date: Feb 2018, volume: 19, issue:1, pages: 14 - 16
Publisher: IEEE
 
» Double-Differential-Fed, Dual-Polarized Patch Antenna With 90 dB Interport RF Isolation for a 2.4 GHz In-Band Full-Duplex Transceiver
Abstract:
This letter presents a 2.4 GHz, dual-polarized microstrip patch antenna with extremely high interport isolation for a shared antenna architecture-based in-band full-duplex transceiver. The presented antenna configuration is based on four-ports linearly polarized single radiating element with differential feeding for both transmit and receive operation. The double-differential feeding using two identical 3 dB/180° ring hybrid couplers with nice amplitude and phase balance effectively suppresses the interport RF leakage to achieve very high isolation. The prototype of the proposed antenna architecture is implemented using a 1.6 mm thick general-purpose FR-4 substrate. The implemented antenna provides more than 90 and 80 dB interport RF isolation for 20 and 40 MHz bandwidths, respectively, in addition to more than 98 dB port-to-port peak isolation when measured inside an anechoic chamber. To the best of our knowledge, this is the highest amount of RF isolation reported for a single dual-polarized patch antenna.
Autors: Haq Nawaz;Ibrahim Tekin;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 287 - 290
Publisher: IEEE
 
» Double-Directional Dual-Polarimetric Cluster-Based Characterization of 70–77 GHz Indoor Channels
Abstract:
This paper presents 70–77 GHz wideband channel characteristics of delay, spatial, and polarimetric domains for small office and entrance hall scenarios. Based on measured multidimensional power spectra of delay, and directions (i.e., azimuth and elevation) of departure and of arrival, multipath clusters were detected using the K-means, threshold-based, and Gaussian-mixture-model clustering algorithms. The spatial positions and directions of clusters, including the first- and last-hop scatterers, are determined using a measurement-based ray tracer method. Our experimental analysis reveals that the composite and cluster-level channel behaviors are considerably dependent on the geometry of environments, the interaction/bouncing order between a wave and objects, the position of transmitter and receiver, the underlying antenna type, and the polarimetric combination. The angular spread of arrival is observed larger than that of departure, and the characteristics for the horizontal polarization are comparable with those for vertical polarization. Our results also manifest the merits of threshold-based clustering algorithm in terms of clusters’ compactness, separation, and exclusiveness. We further find that the identified interaction points exhibit excellent agreement with real physical objects existing in the environment. Based on these results, an indoor stochastic channel model is established not only for the composite parameters and cluster characteristics, but also for the first- and last-hop scatterers’ position, direction, and their dispersive statistics. This model can be used to generate channel realizations of reasonable spatial consistency.
Autors: Cen Ling;Xuefeng Yin;Robert Müller;Stephan Häfner;Diego Dupleich;Christian Schneider;Jian Luo;Hua Yan;Reiner Thomä;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 857 - 870
Publisher: IEEE
 
» Downlink Resource Allocation Under Time-Varying Interference: Fairness and Throughput Optimality
Abstract:
We address the problem of downlink resource allocation in the presence of time-varying interference. We consider a scenario where users served by a base station face interference from a neighboring base station. We model the interference from the neighboring base station as an ON/OFF renewal process, that arises due to its idle and busy cycles. The users feedback their downlink signal to interference plus noise ratio (SINR) values to their base station, but these values are outdated. In this setting, we characterize how the resource allocation layer can optimally exploit the reported SINR values, which could be unreliable due to time-varying interference. In particular, we propose resource allocation policies in two well-known paradigms. First, we address the problem of –fair scheduling, and propose a policy that ensures asymptotic convergence to the optimal –fair throughput. Second, we propose a throughput optimal resource allocation policy, i.e., a policy that can stably support the largest possible set of traffic rates under the interference scenario considered. Estimating the outage probability from the outdated SINR values plays an important role in both scheduling paradigms, and we accomplish this using tool from renewal theory.
Autors: Ravi Kiran Raman;Krishna Jagannathan;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 722 - 735
Publisher: IEEE
 
» DropBand: A Simple and Effective Method for Promoting the Scene Classification Accuracy of Convolutional Neural Networks for VHR Remote Sensing Imagery
Abstract:
The dropout and data augmentation techniques are widely used to prevent a convolutional neural network (CNN) from overfitting. However, the dropout technique does not work well when applied to the input channels of neural networks, and data augmentation is usually employed along the image plane. In this letter, we present DropBand, which is a simple and effective method of promoting the classification accuracy of CNNs for very-high-resolution remote sensing image scenes. In DropBand, more training samples are generated by dropping certain spectral bands out of original images. Furthermore, all samples with the same set of spectral bands are collected together to train a base CNN. The final prediction for a test sample is represented by the combination of outputs of all base CNNs. The experimental results for three publicly available data sets, i.e., the SAT-4, SAT-6, and UC-Merced image data sets, show that DropBand can significantly improve the classification accuracy of a CNN.
Autors: Naisen Yang;Hong Tang;Hongquan Sun;Xin Yang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Feb 2018, volume: 15, issue:2, pages: 257 - 261
Publisher: IEEE
 
» DSIP: A Scalable Inference Accelerator for Convolutional Neural Networks
Abstract:
This paper presents a scalable inference accelerator called a deep-learning specific instruction-set processor (DSIP) to support various convolutional neural networks (CNNs). For CNNs requiring a large amount of computations and memory accesses, a programmable inference system called master–slave instruction set architecture (ISA) is newly proposed to achieve high flexibility, processing speed, and energy efficiency. The master is responsible for sending and receiving feature maps in order to deal with neural networks in a scalable way, and the slave performs CNN operations, such as multiply accumulate, max pooling, and activation functions, on the features received from the master. The master–slave ISA maximizes computation speed by overlapping the off-chip data transmission and the CNN operations, and reduces power consumption by performing the convolution incrementally to reuse input and partial-sum data as maximally as possible. An inference system can be configured by connecting multiple DSIPs in a form of either 1-D or 2-D chain structure in order to enhance computation speed further. To evaluate the proposed accelerator, a prototype chip is implemented and evaluated for AlexNet. Compared to the state-of-the-art accelerator, the DSIP-based system enhances the energy efficiency by 2.17.
Autors: Jihyuck Jo;Soyoung Cha;Dayoung Rho;In-Cheol Park;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2018, volume: 53, issue:2, pages: 605 - 618
Publisher: IEEE
 
» Dual Compressed Sensing Method for Solving Electromagnetic Scattering Problems by Method of Moments
Abstract:
Rapid and accurate calculation of electromagnetic scattering problems over a wide incident angle range is a difficult but valuable subject in computational electromagnetics (CEM). Traditional methods need to calculate repeatedly at each finer angle step, which leads to low efficiency. Based on the recently proposed compressed sensing (CS) method in CEM, a new scheme is proposed to further improve the computation efficiency, in which CS is used two times to form an undetermined equation model and incident sources including much information of incident angles simultaneously. Theoretical frame and specific formulas are derived in detail, and numerical results verify that it provides an efficient technical route for solving electromagnetic scattering problems.
Autors: Xinyuan Cao;Mingsheng Chen;Xianliang Wu;Meng Kong;Jinhua Hu;Yanyan Zhu;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 267 - 270
Publisher: IEEE
 
» Dual of Defected Ground Structure for Coplanar Stripline
Abstract:
Defected ground structures (DGS) have been used with microstrip and coplanar waveguide (CPW), but until now no comparable structure has been demonstrated for coplanar stripline (CPS), probably because there is no “ground plane.” This letter introduces a dual of DGS for CPS with dual properties, or it acts as a shunt, series RLC circuit that creates an equivalent shunt short circuit at the resonant frequency, which is the dual of the DGS in microstrip or CPW.
Autors: George E. Ponchak;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Feb 2018, volume: 28, issue:2, pages: 105 - 107
Publisher: IEEE
 
» Dual-Band and Low-Profile Differentially Fed Slot Antenna for Wide-Angle Scanning Phased Array
Abstract:
A novel dual-band slot antenna with low profile is proposed. The slot antenna is constructed on dual-layer substrates, in which a metal cavity is fabricated by metalized vias. The antenna is fed by a differential scheme, so it can be easily integrated with other systems. The proposed antenna can operate at dual resonant frequencies because of the metal cavity and the radiating slot. A corresponding differential feeding network is constructed on another substrate. The half-power beamwidth of the slot antenna's radiation pattern is wide in the electric plane ( E-plane), and it is suitable to be applied to wide-angle scanning phased arrays. The phased array built by the slot antenna can realize wide-angle scanning within 3 dB peak gain fluctuation in the E -plane at both frequencies. Measured results show that the phased array can scan from –67° to 69° at 5.02 GHz and from –62° to 64° at 5.58 GHz.
Autors: Jiajia Guo;Shaoqiu Xiao;Shaowei Liao;Bingzhong Wang;Quan Xue;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 259 - 262
Publisher: IEEE
 
» Dual-Frequency Ultrasound Transducers for the Detection of Morphological Changes of Deep-Layered Muscles
Abstract:
It is evident that surface electromyography (sEMG)-based sensing approach for human–machine interfaces has some inherent limitations for applications requiring morphological changes information of deep-layered muscles, such as dexterous prosthetic hands. In this paper, the design, simulation, fabrication, and evaluation for a series of novel structured ultrasound transducers are conducted in order to develop a type of A-mode ultrasound transducers that overcome the drawbacks of the sEMG-based sensing. The transducers cover single-frequency and dual-frequency types. Their key parameters, the acoustic impedance and thickness of the matching layer, are simulated and verified by PZFlex. The parameters are designed as 0.3 times of the 1–3 composite piezoelectric’s acoustic impedance and 0.25 times of the wavelength, respectively. The characterizations of the dual-frequency transducers significantly outperform single-frequency transducers. The experiments of recognizing dexterous hand gesture are designed to detect morphological changes information of deep-layered muscles. The classification accuracy improvements with linear discrimination analysis are 7.3% and 4.7%, and with support vector machine are 14.1% and 13.4% for the horizontal stacked and annulus array. This preliminary study concludes that the dual-frequency transducers have huge potential for applications that need contraction information of deep-layered muscles over the single-frequency transducers, letting alone sEMG-based sensors.
Autors: Xueli Sun;Xingchen Yang;Xiangyang Zhu;Honghai Liu;
Appeared in: IEEE Sensors Journal
Publication date: Feb 2018, volume: 18, issue:4, pages: 1373 - 1383
Publisher: IEEE
 
» Dual-Loop Digital Control of a Three-Phase Power Supply Unit With Reduced Sensor Count
Abstract:
Widespread deployment of voltage source inverter units in high penetration applications such as distributed generation and stand-alone renewable energy conditioning imposes stringent demands on reliability and output voltage regulation. Reported literature provides numerous solutions for output voltage regulation, which includes twin aspects of command tracking and output impedance control. Most of these methods rely on the measurement of at least two separate variables per phase, which compromises overall reliability. This paper focuses on a dual-loop voltage regulation approach requiring only output voltage measurement. The outer loop of a control scheme is used to assure prompt tracking of the inverter output voltage, whereas the inner derivative feedback loop improves system stability by damping the output filter resonance. Digital realization of this derivative term is generally a challenge with many methods currently developed for resolving it. These methods are, however, still facing drawbacks, which have inclusively been explained in this paper. Subsequently, a new digital derivative is proposed whose performance is predicted analytically and then validated through experimental results with a 7.5-kVA inverter prototype.
Autors: Sanjay Tolani;Sridhar Joshi;Parthasarathi Sensarma;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 367 - 375
Publisher: IEEE
 
» Dual-Mode Generalized Spatial Modulation MIMO for Visible Light Communications
Abstract:
In this letter, we propose the optimal constellation designs of the single-mode and dual-mode generalized spatial modulation (GSM) in terms of the average optical power for indoor visible light communication systems. At receiver, an ordered-block maximum likelihood detection is performed to balance the tradeoff between the performance and the computational complexity. Our simulation results show that the dual-mode scheme outperforms SM and single-mode GSM by about 4 and 2 dB, respectively, for 5 bit/s/Hz in terms of bit error rate.
Autors: C. Rajesh Kumar;R. K. Jeyachitra;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 280 - 283
Publisher: IEEE
 
» Dual-Operation Regime Thulium-Doped Fiber Laser and Its Applications in Cascaded Raman Light and Supercontinuum Generation
Abstract:
We report on a passively mode-locked thulium-doped fiber laser (TDFL) with dual operation regimes and applications in cascaded Raman light and supercontinuum generation. The mode-locking is initiated by using a semiconductor saturable absorber mirror (SESAM) and can operate at both fundamental mode-locking and noise-like twin-pulse regimes. Output power can be scaled up through two-stage amplifications, and then was further fed into a segment of ultrahigh numerical aperture (NA) single-mode fiber with a length of ∼30 m. At the fundamental mode-locking regime, two orders of stokes lights can be generated, centered at 2.13 and 2.35 μm, respectively, with a maximum total power of 3.75 W. At the noise-like twin-pulse regime, a near-infrared supercontinuum from 1.93 to 2.46 μm was generated with a maximum average output power of 2.5 W. It is, to the best of our knowledge, the first demonstration of both cascaded Raman light and supercontinuum generation with the same system.
Autors: Zhijian Zheng;Deqin Ouyang;Junqing Zhao;Peiguang Yan;Jinzhang Wang;Shenghua Lin;Shuangchen Ruan;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 9
Publisher: IEEE
 
» Dynamic Analysis of Small Wind Turbines Frequency Support Capability in a Low-Power Wind-Diesel Microgrid
Abstract:
When wind power accounts for a large portion of the islanded microgrid power, it may need to support the ac bus frequency regulation. The increasing penetration of variable speed wind turbines (WTs) in microgrids leads to a lower inertia, as the rotational speed of the turbine and the grid is decoupled by power electronic converters. Lower system inertia results in a larger and faster frequency deviation after occurrence of abrupt variations on generation and load. It is possible to implement control loops in the WT converters to provide a virtual inertia and support frequency regulation in the microgrid. This paper investigates the variables related to the frequency compensation capability of WT, such as kinetic energy, dc-link capacitance, turbine size, wind penetration, number of turbines, operating region along the power curve, power reserve and droop control gain, etc. The analysis is structured as a design of experiment (DOE) to have a clear and organized comparison of multiple system configurations. An optimal control technique is applied to provide fair comparison among the system variables. A flowchart explaining how the DOE and controllers gains were defined is provided.
Autors: Raffael Engleitner;Ademir Nied;Mariana Santos Matos Cavalca;Jean Patric da Costa;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 102 - 111
Publisher: IEEE
 
» Dynamic Linear Gradient Array for Traveling Wave Magnetic Particle Imaging
Abstract:
Magnetic particle imaging (MPI) is a young imaging modality using the nonlinear magnetization properties of superparamagnetic iron-oxide nanoparticles to acquire them. It is a highly sensitive and fast method allowing both a quantitative and a qualitative analysis of the measured signal. Since its first publication in 2005, several different scanner types have been presented. Most of them work with permanent magnets and therefore have a small field of view. In 2014, an alternative scanner concept, the traveling wave MPI (TWMPI), was presented, which allows scanning an entire mouse-sized volume at once. In this paper, a detailed description of the main field generator, the dynamic linear gradient array (dLGA), used for TWMPI is given. This paper guides the reader to the first dLGA prototype, deriving relations between the length of the dLGA and the diameter of the segment coils.
Autors: P. Vogel;P. Klauer;M. A. Rückert;T. A. Bley;W. H. Kullmann;P. M. Jakob;V. C. Behr;
Appeared in: IEEE Transactions on Magnetics
Publication date: Feb 2018, volume: 54, issue:2, pages: 1 - 9
Publisher: IEEE
 
» Dynamic Modeling and Feasibility Analysis of a Solid-State Transformer-Based Power Distribution System
Abstract:
This paper presents a comprehensive state-space dynamic model of a future power distribution system for plug-and-play interface of distributed renewable energy resources and distributed energy storage devices. The system, called the future renewable electric energy delivery and management (FREEDM) system, comprises of multiple solid-state transformers (SSTs), and load, generation, and storage connected to each SST in a distributed network. The system allows for high penetration of renewable generation with energy storage at the distribution level. A physics-based 70th-order state-space average model is first developed considering the physical and controller properties of a single-SST FREEDM system along with its distribution components. This fundamental model is then extended to build a multi-SST FREEDM system for feasibility and dynamics behavior analysis of the entire system, which is essential to ensure system power balance. The full average model with multiple SSTs has been incorporated in an IEEE 34 bus distribution testbed for a scaled analysis of the system.
Autors: Md Tanvir Arafat Khan;Alireza Afiat Milani;Aranya Chakrabortty;Iqbal Husain;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 551 - 562
Publisher: IEEE
 
» Dynamic Power Management and Control of a PV PEM Fuel-Cell-Based Standalone ac/dc Microgrid Using Hybrid Energy Storage
Abstract:
In this paper, a dynamic power management scheme (PMS) is proposed for a standalone hybrid ac/dc microgrid, which constitutes a photovoltaic (PV)-based renewable energy source, a proton exchange membrane fuel cell (FC) as a secondary power source, and a battery and a supercapacitor as hybrid energy storage. The power management algorithm accounts for seamless operation of the microgrid under various modes and state-of-charge limit conditions of hybrid energy storage when all the sources, storages, and loads are connected directly at the dc link. The PMS generates current references for dc converter current controllers of the FC, the battery, and the supercapacitor. The average and fluctuating power components are separated using a moving average filter. The dc-link voltage regulation under dynamic changes in load and source power variation is proposed. Also, PV power curtailment through control is formulated. The proposed power management is modified and extended to multiple PV generation systems and batteries, with all the sources and storages geographically distributed and operating under multitime-scale adaptive-droop-based control with supervisory control for mode transition. The proposed PMS is validated using simulation results. Also, field programmable gate array/Labview-based laboratory-scale experimental results are presented to validate the PMS under various critical conditions.
Autors: Rishi Kant Sharma;Sukumar Mishra;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 526 - 538
Publisher: IEEE
 
» Dynamic SCMA Codebook Assignment Methods: A Comparative Study
Abstract:
In this letter, we consider a sparse code multiple access (SCMA) system, in which we assign the subcarriers to users based on the available channel gains between the users and base station over all subcarriers, referred to as channel state information. The effect of this process, referred to here as codebook assignment, has not been considered before on link-level performance of an SCMA. We propose three codebook assignment methods and compare their performance with each other as well as with the conventional case, where no assignment is performed. It is shown that significant performance improvement is achieved when any of the proposed methods is deployed. Through one of the proposed methods, we show that a trade-off between user performance fairness and performance is achievable.
Autors: Milad Dabiri;Hamid Saeedi;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 364 - 367
Publisher: IEEE
 
» Dynamic Spectrum Reservation for CR Networks in the Presence of Channel Failures: Channel Allocation and Reliability Analysis
Abstract:
Providing channel access opportunities for new service requests and guaranteeing continuous connections for ongoing flows until service completion are two challenges for service provisioning in wireless networks. Channel failures, which are typically caused by hardware and software failures or/and by intrinsic instability in radio transmissions, can easily result in network performance degradation. In cognitive radio networks (CRNs), secondary transmissions are inherently vulnerable to connection breaks due to licensed users’ arrivals as well as channel failures. To explore the advantages of channel reservation on performance improvement in error-prone channels, we propose and analyze a dynamic channel reservation (DCR) algorithm and a dynamic spectrum access (DSA) scheme with three access privilege variations. The key idea of the DCR algorithm is to reserve a dynamically adjustable number of channels for the interrupted services to maintain service retainability for ongoing users or to enhance channel availability for new users. Furthermore, the DCR algorithm is embedded in the DSA scheme enabling spectrum access of primary and secondary users with different access privileges based on access flexibility for licensed shared access. The performance of such a CRN in the presence of homogeneous and heterogeneous channel failures is investigated considering different channel failure and repair rates.
Autors: Indika A. M. Balapuwaduge;Frank Y. Li;Vicent Pla;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 882 - 898
Publisher: IEEE
 
» Dynamically Adaptable Pipeline for Energy-Efficient Microarchitectures Under Wide Voltage Scaling
Abstract:
This paper introduces dynamically adaptable pipelines to enable microarchitecture-driven voltage scaling, adapting the microarchitecture to the most energy-efficient configuration for a time-varying throughput target or supply voltage requirement . Dynamic adaptation of the pipeline depth is introduced to curtail the contribution that dominates the overall energy (e.g., dynamic, clock, and leakage), as dictated by the throughput target and . Microarchitectural adaptation of the pipeline depth also flattens the energy dependence on around the minimum-energy point, thus facilitating nearly minimum-energy operation in the presence of inaccuracies in (e.g., discretization and non-idealities). Dynamically adaptable pipelines can be fully integrated with automated digital flows at design time and with dynamic voltage scaling schemes at run time. The proposed approach is demonstrated with a 256-point radix-4 fixed-point FFT engine on a 40-nm test chip. Measurements show energy savings up to 30% (38%) at iso-throughput (iso-voltage) in an area and the maximum performance penalty of 5% and 11%, respectively.
Autors: Saurabh Jain;Longyang Lin;Massimo Alioto;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2018, volume: 53, issue:2, pages: 632 - 641
Publisher: IEEE
 
» Dynamically Consistent Online Adaptation of Fast Motions for Robotic Manipulators
Abstract:
The planning and execution of real-world robotic tasks largely depends on the ability to generate feasible motions online in response to changing environment conditions or goals. A spline deformation method is able to modify a given trajectory so that it matches the new boundary conditions, e.g., on positions, velocities, accelerations, etc. At the same time, the deformed motion preserves velocity, acceleration, jerk, or higher derivatives of motion profile of the precalculated trajectory. The deformed motion possessing such properties can be expressed by translation of original trajectory and spline interpolation. This spline decomposition considerably reduces the computational complexity and allows real-time execution. Formal feasibility guarantees are provided for the deformed trajectory and for the resulting torques. These guarantees are based on the special properties of Bernstein polynomials used for the deformation and on the structure of the chosen computed-torque control scheme. The approach is experimentally evaluated in a number of planar volleyball experiments using 3 degree-of-freedom robots and human participants.
Autors: Alexander Pekarovskiy;Thomas Nierhoff;Sandra Hirche;Martin Buss;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 166 - 182
Publisher: IEEE
 
» Dynamically Regulating Mobile Application Permissions
Abstract:
Current smartphone operating systems employ permission systems to regulate how apps access sensitive resources. These systems are not well-aligned with users’ privacy expectations: users often have no idea how often and under what circumstances their personal data is accessed. We conducted a 131-person field study to devise ways to systematically reduce this disconnect between expectations and reality. We found that a significant portion of participants make contextual privacy decisions: when determining whether access to sensitive data is appropriate, they consider what they are doing on their phones at the time, including whether they are actively using the applications requesting their data. We show that current privacy mechanisms do not do a good job of accounting for these contextual factors, but that by applying machine learning to account for context, we can reduce privacy violations by 80, while also minimizing user involvement.
Autors: Primal Wijesekera;Arjun Baokar;Lynn Tsai;Joel Reardon;Serge Egelman;David Wagner;Konstantin Beznosov;
Appeared in: IEEE Security & Privacy
Publication date: Feb 2018, volume: 16, issue:1, pages: 64 - 71
Publisher: IEEE
 
» Dynamics Model and Vibration Control of Piezoelectric Feeder in Semiconductor Manufacturing Assembly
Abstract:
A piezoelectric vibration feeder is a necessary device for semiconductor manufacturing assembly. Its function is to automatically transport individual chip parts by precision vibration instead of by manual operation. In this paper, a mechanical structure for the piezoelectric feeder and electrical controller is designed and a prototype is developed. A vibration simulation model is established in ANSYS by the finite element method (FEM), and the frequency and vibration modal is attained. The mass-elastic model is established and the frequency is calculated by the numerical method. To drive and control the vibration feeder, a hardware driver consisting of an ARM microcontroller, a sinusoidal pulse width modulation driver module, an inverter circuit of insulated gate bipolar transistor modules, and an LC filter is designed. To achieve resonant vibration, a self-tuned proportional integral derivative (PID) controller for frequency tracking is investigated using MATLAB Simulink simulation. The dynamics and performance of vibration control are then verified through experimental testing using a laser Doppler vibrometer and an impedance analyzer. The mechanical frequencies of the piezoelectric feeder in the FEM, the numerical model, and the experimental measurement are found to agree well. The PID controller used for frequency tracking ensures the resonant vibration, which improves the efficiency and robustness of the piezoelectric feeder.
Autors: Zhili Long;Hao Shen;Jianguo Zhang;Shuang Zhao;Yongcheng Lin;Zuohua Li;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Feb 2018, volume: 31, issue:1, pages: 97 - 107
Publisher: IEEE
 
» Easy PRAM-Based High-Performance Parallel Programming with ICE
Abstract:
Parallel machines have become more widely used. Unfortunately parallel programming technologies have advanced at a much slower pace except for regular programs. For irregular programs, this advancement is inhibited by high synchronization costs, non-loop parallelism, non-array data structures, recursively expressed parallelism and parallelism that is too fine-grained to be exploitable. We present ICE, a new parallel programming language that is easy-to-program, since: (i) ICE is a synchronous, lock-step language so there is no need for programmer-specified synchronization; (ii) for a PRAM algorithm its ICE program amounts to directly transcribing it; and (iii) the PRAM algorithmic theory offers unique wealth of parallel algorithms and techniques. We propose ICE to be a part of an ecosystem consisting of the XMT architecture, the PRAM algorithmic model, and ICE itself, that together deliver on the twin goal of easy programming and efficient parallelization of irregular programs. The XMT architecture, developed at UMD, can exploit fine-grained parallelism in irregular programs. We have built the ICE compiler which translates the ICE language into the multithreaded XMTC language; the significance of this is that multi-threading is a feature shared by practically all current scalable parallel programming languages thus providing a method to compile ICE code. As one indication of ease of programming, we observed a reduction in code size in 11 out of 16 benchmarks as compared to hand-optimized XMTC. For these programs, the average reduction in number of lines of code was 35.5 percent. The remaining 5 benchmarks had almost the same code size for both ICE and hand-optimized XMTC. Our main result is perhaps surprising: The run-time was comparable to XMTC with a 0.53 percent average gain for ICE across all benchmarks.
Autors: Fady Ghanim;Uzi Vishkin;Rajeev Barua;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Feb 2018, volume: 29, issue:2, pages: 377 - 390
Publisher: IEEE
 
» Eco-Driving Assistance System for a Manual Transmission Bus Based on Machine Learning
Abstract:
Driving assistance systems (DAS) is a key technology to improve fuel economy for in-use vehicles. This also reduces the operational cost of running a fleet of these vehicles, such as city buses. In this paper, we develop a novel white-box evaluation model using machine learning for a manual transmission bus based on previous research about fuel consumption sensitivity to driving style. Using the proposed evaluation model, an algorithm for learning path planning (LPP) for a driving style is also proposed. The LPP method plans a step-by-step shortest learning path for different driving styles to achieve eco-driving, while increasing the driver’s acceptance and adaptation of DAS. Simulation results based on vehicle and engine physical models show that the proposed evaluation model, a pure data model, can be used as an alternative to physical model for the eco-driving prompt strategy. The results of the verification show that the proposed strategy can progressively guide the driver to improve the fuel consumption by 6.25% with minimal changes to driver’s driving task and driving style.
Autors: Hongjie Ma;Hui Xie;David Brown;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Feb 2018, volume: 19, issue:2, pages: 572 - 581
Publisher: IEEE
 
» Edge Computing for the Internet of Things
Abstract:
Autors: Ju Ren;Yi Pan;Andrzej Goscinski;Raheem A. Beyah;
Appeared in: IEEE Network
Publication date: Feb 2018, volume: 32, issue:1, pages: 6 - 7
Publisher: IEEE
 
» Edge Computing Gateway of the Industrial Internet of Things Using Multiple Collaborative Microcontrollers
Abstract:
An Internet of Things gateway serves as a key intermediary between numerous smart things and their corresponding cloud networking servers. A typical conventional gateway system uses a high-level embedded microcontroller (MCU) as its core; that MCU performs low-level perception-layer device network management, upper-level cloud server functions, and remote mobile computation services. However, in edge computing, many factors need to be considered when designing an IoT gateway, such as minimizing the response time, the power consumption, and the bandwidth cost. Regarding system scalability, computational efficiency, and communication efficiency, solutions that use a single MCU cannot deliver IoT functionality such as big data collection, management, real-time communication, expandable peripherals, and various other services. Therefore, this article proposes an innovative multi-MCU system framework combining a field-programmable- gate-array-based hardware bridge and multiple scalable MCUs to realize an edge gateway of a smart sensor fieldbus network. Through distributed and collaborative computing, the multi-MCU edge gateway can efficiently perform fieldbus network management, embedded data collection, and networking communication, thereby considerably reducing the real-time power consumption and improving scalability compared to the existing industrial IoT solutions.
Autors: Ching-Han Chen;Ming-Yi Lin;Chung-Chi Liu;
Appeared in: IEEE Network
Publication date: Feb 2018, volume: 32, issue:1, pages: 24 - 32
Publisher: IEEE
 
» Editor's Note
Abstract:
Autors: Nei Kato;Mohsen Guizani;
Appeared in: IEEE Network
Publication date: Feb 2018, volume: 32, issue:1, pages: 3 - 3
Publisher: IEEE
 
» Editor-in-Chief Message: Embracing the Era of Intelligent Visual Technology and Systems
Abstract:
It is such a great honor and pleasure for me to assume the role of Editor-in-Chief of IEEE Transactions on Circuits and Systems for Video Technology (TCSVT), starting in January 2018. I have been involved in TCSVT for a long time, initially as a reader as early as in 1993 when I was still a graduate student, then as a long-time contributor in the role of an author and a reviewer, as an Associate Editor from 2002 to 2008, and later as a Deputy Editor-in-Chief from 2014 to 2017. I look forward to this exciting yet challenging opportunity to lead TCSVT to the next level.
Autors: Shipeng Li;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Feb 2018, volume: 28, issue:2, pages: 273 - 274
Publisher: IEEE
 
» Editorial
Abstract:
Dear fellow dielectricians, It will be an honor and a pleasure to serve as your DEIS president during 2018. My special thanks go to the DEIS Administrative Committee for entrusting me with this office; to the former presidents Simon Rowland, Frank Hegeler, and Paul Lewin and to the outgoing Standing-Committee chairs for their support and advice; and to the new administrative and technical vice presidents, Paul Gaberson and Brian Stewart, as well as the new secretary, Axel Mellinger, and the newly appointed or reappointed Standing-Committee chairs for kindly agreeing to dedicate valuable time as DEIS volunteers. I very much look forward to working with all of you. Together, we will make a difference.
Autors: Reimund Gerhard;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: Feb 2018, volume: 34, issue:1, pages: 4 - 4
Publisher: IEEE
 
» Editorial Celebrating 25 Years of the IEEE Transactions on Fuzzy Systems
Abstract:
Autors: J. BEZDEK;J. KELLER;N. PAL;C.-T. LIN;J. GARIBALDI;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Feb 2018, volume: 26, issue:1, pages: 1 - 5
Publisher: IEEE
 
» Editorial February 2018 Issue
Abstract:
This issue of the IEEE Transactions on Engineering Management includes 13 research articles. The relevance and usefulness of the articles are summarized.
Autors: Rajiv Sabherwal;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Feb 2018, volume: 65, issue:1, pages: 1 - 5
Publisher: IEEE
 
» Effect of a Trap Zone in Reducing Nanoparticle Contamination of Wafers and Photomasks in Parallel Airflowp
Abstract:
Particle contamination control is important for increasing the yield in semiconductor manufacturing. In this paper, a trap zone was suggested to reduce the level of particulate contamination of wafers and photomasks during transport in horizontal direction. Trap zone efficiency was numerically and theoretically analyzed by calculating local deposition velocity onto a critical surface representing a wafer or a photomask. The effects of diffusion, gravitational settling, convection, and thermophoresis on particle behavior were considered. The deposition velocity onto the critical surface was found to be effectively reduced with the use of the trap zone, especially for nanoparticles of large diffusivity. As the trap zone became longer, the degree of critical surface contamination by nanoparticles was estimated to be more reduced. An equation was suggested to estimate the reduction of particulate contamination of the critical surface as a function of the trap zone length. It is anticipated that the results of this paper are very helpful for designing wafer/photomask transport systems with a reduced level of contamination by nanoparticles.
Autors: Sang-Hee Woo;Jungsuk Lee;Se-Jin Yook;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Feb 2018, volume: 31, issue:1, pages: 87 - 96
Publisher: IEEE
 
» Effect of Control-Loops Interactions on Power Stability Limits of VSC Integrated to AC System
Abstract:
This paper investigates the effect of control-loops interactions on power stability limits of the voltage-source converter (VSC) as connected to an ac system. The focus is put on the physical mechanism of the control-loops interactions in the VSC, revealing that interactions among the control loops result in the production of an additional loop. The open-loop gain of the additional loop is employed to quantify the severity of the control-loop interactions. Furthermore, the power current sensitivity, closely related to control-loops interactions, is applied to estimate the maximum transferrable power of the VSC connected to an ac grid. On that basis, stability analysis results show that interactions between dc-link voltage control and phase-locked loop restrict the power angle to about 51° for stable operation with no dynamic reactive power supported. Conversely, the system is capable of approaching the ac-side maximum power transfer limits with alternating voltage control included. Simulations in MATLAB/Simulink are conducted to validate the stability analysis.
Autors: Yunhui Huang;Dong Wang;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 301 - 310
Publisher: IEEE
 
» Effect of La Addition on the Electrical Characteristics and Stability of Solution-Processed LaInO Thin-Film Transistors With High- ${k}$ ZrO2 Gate Insulator
Abstract:
In this paper, solution-processed ZrO2 thin films are used to be as insulting layers for lanthanum indium oxide (LaInO) thin-film transistors (TFTs) with different La doping contents. The influence of La addition on the electrical properties and stability under bias stress and temperatures stress for LaInO TFTs is investigated in detail. With the improvement of La doping contents, the saturation mobility () decreases from 48.8 to 32.7 cm2 and the threshold voltage (VT) increases from 1.12 to 1.76 V. When La doping concentration is 10 mol%, LaInO TFT has a small subthreshold swing of 0.12 V/dec. Meanwhile, the stability is improved obviously. It is attributed to the strong bonding strength of La–O relative to that of In–O, resulting in the reduction of trap states. X-ray photoelectron spectroscopy shows that the generation of oxygen vacancies can effectively be suppressed by La addition. The calculation of density of states and the measurement of the capacitance–voltage can also further confirm that the density of trap states is decreased by La addition, and thus the stability of LaInO TFTs can get an obvious improvement.
Autors: Cheng-Yu Zhao;Jun Li;De-Yao Zhong;Chuan-Xin Huang;Jian-Hua Zhang;Xi-Feng Li;Xue-Yin Jiang;Zhi-Lin Zhang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 526 - 532
Publisher: IEEE
 
» Effect of Motor Voltage Unbalance on Motor Vibration: Test and Evaluation
Abstract:
There have been many discussions on the importance of balanced power supply for both best performance and for lower vibration during operation of industrial motors in petrochemical duty and related installations. Results of tests that were conducted on several low-voltage IEEE 841 motors to observe the effect on vibration due to unbalanced power supply will be presented. Various increments of voltage imbalance from 1% up to 10% were tested and monitored on several pole speeds. This paper will present actual test data collected, along with a discussion on how these results relate and impact the various vibration testing and operational conditions provided within industry standards.
Autors: Matthew Campbell;Gabriel Arce;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 905 - 911
Publisher: IEEE
 
» Effective and Efficient Detection of Moving Targets From a UAV’s Camera
Abstract:
Accurate and fast detection of the moving targets from a moving camera are an important yet challenging problem, especially when the computational resources are limited. In this paper, we propose an effective, efficient, and robust method to accurately detect and segment multiple independently moving foreground targets from a video sequence taken by a monocular moving camera [e.g., onboard an unmanned aerial vehicle (UAV)]. Our proposed method advances the existing methods in a number of ways, where: 1) camera motion is estimated through tracking background keypoints using pyramidal Lucas–Kanade at every detection interval, for efficiency; 2) foreground segmentation is applied by integrating a local motion history function with spatio-temporal differencing over a sliding window for detecting multiple moving targets, while the perspective homography is used at image registration for effectiveness; and 3) the detection interval is adjusted dynamically based on a rule-of-thumb technique and considering camera setup parameters for robustness. The proposed method has been tested on a variety of scenarios using a UAV camera, as well as publically available data sets. Based on the reported results and through comparison with the existing methods, the accuracy of the proposed method in detecting multiple moving targets as well as its capability for real-time implementation has been successfully demonstrated. Our method is also robustly applicable to ground-level cameras for the ITS applications, as confirmed by the experimental results. More specifically, the proposed method shows promising performance compared with the literature in terms of quantitative metrics, while the run-time measures are significantly improved for real-time implementation.
Autors: Sara Minaeian;Jian Liu;Young-Jun Son;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Feb 2018, volume: 19, issue:2, pages: 497 - 506
Publisher: IEEE
 
» Effective Doping Concentration Theory: A New Physical Insight for the Double-RESURF Lateral Power Devices on SOI Substrate
Abstract:
Double-reduced surface field (D-RESURF) technique aims to increase the doping concentration of drift regions and maintain a high breakdown voltage. However, conventional 2-D models are too complicated and unable to elaborate its physical meaning. Hence, the D-RESURF effective doping concentration (EDC) theory is proposed in this paper to explore the physical insight of the D-RESURF effect by equating the sophisticated 2-D structure to a simple 1-D RESURF model with segmented-doped p-n junction. The EDC indicates that an NPNP structure may exist because of the influence of the P-top region. Thus, two electric field valleys and one electric field peak can be formed on the surface. Based on the theory, a 1-D analytical model is presented to qualitatively and quantitatively explore the impact of D-RESURF effect on breakdown mechanism of silicon on insulator lateral double diffusion MOS. The results obtained by the proposed model are found to be sufficiently accurate comparing with TCAD simulation results.
Autors: Jun Zhang;Yu-Feng Guo;David Z. Pan;Ke-Meng Yang;Xiao-Juan Lian;Jia-Fei Yao;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 648 - 654
Publisher: IEEE
 
» Effective Learner-Centered Approach for Teaching an Introductory Digital Systems Course
Abstract:
In the Internet era, students have increasingly lost interest in traditional lectures; as a consequence, their learning motivation and exam performance have decreased. The widespread adoption of learner-centered teaching methods that address this issue faces certain barriers, including: 1) the significant faculty effort necessary to prepare e-learning materials; 2) significant extra time required for active online communication with students; 3) student resistance to taking an active role in their education; and 4) lecturers’ common belief that learner-centered teaching activities do not allow discussion of all the required topics. This paper presents a case study based on one offering of an introductory digital systems course taught with a combination of learner-centered strategies selected to overcome these barriers and improve student performance. These measures included: 1) improving the student-teacher relationship; 2) applying intriguing, inductive, and counterintuitive approaches to introducing new concepts; 3) adopting puzzle-based quizzes integrated with peer instruction; 4) using an audience response system; 5) replacing certain lectures with tutorials; 6) reducing course duration; and 7) using a graphics tablet. The results obtained demonstrate significant improvements in lecture attendance and in student performance. The author believes that the approach presented here can benefit other engineering educators in similar courses.
Autors: Piotr Dȩbiec;
Appeared in: IEEE Transactions on Education
Publication date: Feb 2018, volume: 61, issue:1, pages: 38 - 45
Publisher: IEEE
 
» Effective Removal of Gordon–Haus Jitter in Mode-Locked Fiber Lasers
Abstract:
We demonstrate the effective removal of Gordon–Haus (GH) jitter in mode-locked fiber lasers based on the narrow bandpass filtering, verified from large positive dispersion to large negative dispersion. Simulations and experiments indicate that there exists an optimum filtering bandwidth for the near-zero GH jitter along with the constant directly coupled jitter. The corresponding measured root-mean-square timing jitter (10 kHz to 10 MHz) is restrained within 0.6 dB, even though the net dispersion is largely varied by 70% of the intracavity fiber dispersion. The demonstrated effective GH jitter elimination free of the dispersion management gives an easy way for the low-jitter laser design and the related high-precision applications outside the laboratory.
Autors: Peng Qin;Sijia Wang;Minglie Hu;Youjian Song;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 8
Publisher: IEEE
 
» Effects of Magnetostriction on Electromagnetic Motor Vibration at Sideband Frequencies
Abstract:
This paper discusses the effects of magnetostrictions (MSs) on the vibrations of stator core of electric motor driven by pulse width modulation controllers. Special attention is given to the vibration shapes at the sideband frequencies of the switching frequency. First, based on the measured vibration shapes of an electric motor, it is shown that the vibration shapes at the sideband frequencies are strongly affected by the electromagnetic force (EM) distribution. Next, we estimate the vibration shapes of the stator by conducting coupled magnetostatic and structural finite-element analyses. It is shown that the computed and the measured vibration shapes at each sideband frequency are in good agreement. It is then demonstrated that the contributions of the EM and the MS on the stator vibration shape at each side band frequency can clearly be explained by the phase pattern of magnetic flux density on the stator teeth and back yoke of the stator core.
Autors: Masakatsu Kuroishi;Akira Saito;
Appeared in: IEEE Transactions on Magnetics
Publication date: Feb 2018, volume: 54, issue:2, pages: 1 - 8
Publisher: IEEE
 
» Efficient Algorithms for Sequence Analysis with Entropic Profiles
Abstract:
Entropy, being closely related to repetitiveness and compressibility, is a widely used information-related measure to assess the degree of predictability of a sequence. Entropic profiles are based on information theory principles, and can be used to study the under-/over-representation of subwords, by also providing information about the scale of conserved DNA regions. Here, we focus on the algorithmic aspects related to entropic profiles. In particular, we propose linear time algorithms for their computation that rely on suffix-based data structures, more specifically on the truncated suffix tree (TST) and on the enhanced suffix array (ESA). We performed an extensive experimental campaign showing that our algorithms, beside being faster, make it possible the analysis of longer sequences, even for high degrees of resolution, than state of the art algorithms.
Autors: Cinzia Pizzi;Mattia Ornamenti;Simone Spangaro;Simona E. Rombo;Laxmi Parida;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Feb 2018, volume: 15, issue:1, pages: 117 - 128
Publisher: IEEE
 
» Efficient and Privacy-Preserving Outsourced Calculation of Rational Numbers
Abstract:
In this paper, we propose a framework for efficient and privacy-preserving outsourced calculation of rational numbers, which we refer to as POCR. Using POCR, a user can securely outsource the storing and processing of rational numbers to a cloud server without compromising the security of the (original) data and the computed results. We present the system architecture of POCR and the associated toolkits required in the privacy preserving calculation of integers and rational numbers to ensure that commonly used outsourced operations can be handled on-the-fly. We then prove that the proposed POCR achieves the goal of secure integer and rational number calculation without resulting in privacy leakage to unauthorized parties, and demonstrate the utility and the efficiency of POCR using simulations.
Autors: Ximeng Liu;Kim-Kwang Raymond Choo;Robert H. Deng;Rongxing Lu;Jian Weng;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Feb 2018, volume: 15, issue:1, pages: 27 - 39
Publisher: IEEE
 
» Efficient Coding Architectures for Reed–Solomon and Low-Density Parity-Check Decoders for Magnetic and Other Data Storage Systems
Abstract:
High-performance error correction codes are used in high-density data storage devices to overcome noise and channel impairments. In this paper, we develop novel and efficient decoding architectures for Reed–Solomon (RS) and low-density parity-check (LDPC) codes that are used in almost all data storage devices. First, we present a high-speed low-latency hard-decision-based pipelined RS decoder architecture that computes the error locator polynomial in exactly clock cycles without parallelism. The RS decoder is a two-stage pipelined engine operating at the least latency possible, thereby, significantly reducing the size of the delay buffer. The RS decoder is implemented using Cadence tools and Kintex-7 field programmable gate array (FPGA). The technology-scaled normalized throughput of the pipelined RS decoder is almost two times compared with the existing decoders. The overall processing latency is reduced by almost 80% compared with the existing designs. Second, we design a high-throughput LDPC decoder using layered and non-layered min-sum algorithm based on non-uniform quantization (NUQ) on an FPGA kit. Unlike the standard state-of-the-art uniform quantization used in virtually all decoder circuits, our NUQ technique: 1) achieves a slight performance improvement of ~0.1 dB in the signal-to-noise ratio using equal number of bits and 2) yields 20% area savings (using 1 bit less) for the block RAMs used for storing intermediate check node and variable node messages.
Autors: Arijit Mondal;Satyannarayana Thatimattala;Vamshi Krishna Yalamaddi;Shayan Srinivasa Garani;
Appeared in: IEEE Transactions on Magnetics
Publication date: Feb 2018, volume: 54, issue:2, pages: 1 - 15
Publisher: IEEE
 
» Efficient Decoupling Capacitor Placement Based on Driving Point Impedance
Abstract:
With rapidly increasing switching speeds and surge current requirements, placement of local decoupling capacitors is becoming critically important in high-speed low-power designs. In this paper, utilizing the driving-point impedance (viewed from the device pin) as a metric, a new method is presented for the placement of decoupling capacitors in parallel-plate power ground pairs of high-speed circuits. In the proposed approach, instead of using the traditional trial-and-error method to identify an appropriate placement distance, the process is formulated in the form of a transcendental function. The resulting function is solved using Newton–Raphson (N-R) iterations to give a direct solution for the distance. Also, an analytical representation based on Hankel functions for the driving point impedance and its derivatives is developed to speed up the N-R iterations. The proposed method is validated by comparing the results with the full-wave electromagnetic simulations.
Autors: Ihsan Erdin;Ramachandra Achar;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Feb 2018, volume: 66, issue:2, pages: 669 - 677
Publisher: IEEE
 
» Efficient Distributed All-Pairs Algorithms: Management Using Optimal Cyclic Quorums
Abstract:
All Pairs problems occur in many research fields. The all-pairs problem requires all data elements to be paired with all other data elements. With the advent of new data intensive big data applications and increase in data size, methods to reduce memory foot print and distribute to work equally across compute nodes are needed. In this paper, we propose cyclic quorum sets for all-pairs algorithm computations to reduce memory foot print. We show that the cyclic quorum sets have a unique all-pairs property that allows for minimal data replication. The cyclic quorums set based computing requires only size memory, up to 50 percent smaller than the dual array implementations proposed earlier, and significantly smaller than solutions requiring all data in each node. Computation can be distributed efficiently and more importantly and are communication-less after initial data distribution, which is a huge advantage in minimizing computation time. Scaling from 16 to 512 cores (1 to 32 compute nodes), our application experiments on a real dataset demonstrated scalability with greater than 150x (super-linear) speedup with less than 1/4th the memory usage per node in our experiments.
Autors: Cory James Kleinheksel;Arun K. Somani;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Feb 2018, volume: 29, issue:2, pages: 391 - 404
Publisher: IEEE
 
» Efficient Modeling and Analysis of the Multiple Air Hole Effect in Substrate-Integrated Waveguide
Abstract:
A wide spectrum of potential applications using substrate-integrated waveguide (SIW) technologies in conjunction with air hole regions is introduced, and an efficient analysis method to cope with the multiple air hole effect in the SIW is proposed where we present the generalized wave equation satisfying the boundary and phase matching conditions to solve the multiple air interface problem, which provides highly accurate dispersion characteristics over the whole frequency band. The proposed approach is compared with a commercial software and verified by measurement results from the fabricated samples using Taconic/RF30-7H substrate, and is confirmed to give excellent agreement. Hence, the proposed method is effective for optimum design of SIW circuits for the purpose of low-loss and broadband applications.
Autors: Jin-Yang Kim;Dong-Wan Chun;Hai-Young Lee;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Feb 2018, volume: 28, issue:2, pages: 93 - 95
Publisher: IEEE
 
» Efficient Receive Antenna Selection for Pre-Coding Aided Spatial Modulation
Abstract:
Developed from the recently emerged pre-coding aided spatial modulation (PSM) concept, a class of efficient receives antenna selection (ERAS) techniques are devised. Aiming at approaching the optimal RAS performance in context of the PAM system, we derive the upper bound performance of RAS-PAM in two different ways, by utilizing the condition number and eigenvalue and Wishart distribution feature for the channel matrix. Our performance results demonstrate that the proposed ERAS techniques are capable of effectively improving the transmission performance in comparison with conventional RAS-PSM systems.
Autors: Peibo Wen;Xu He;Yue Xiao;Ping Yang;Rong Shi;Ke Deng;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 416 - 419
Publisher: IEEE
 
» Efficient Recommendation of Aggregate Data Visualizations
Abstract:
Data visualization is a common and effective technique for data exploration. However, for complex data, it is infeasible for an analyst to manually generate and browse all possible visualizations for insights. This observation motivated the need for automated solutions that can effectively recommend such visualizations. The main idea underlying those solutions is to evaluate the utility of all possible visualizations and then recommend the top-k visualizations. This process incurs high data processing cost, that is further aggravated by the presence of numerical dimensional attributes. To address that challenge, we propose novel view recommendation schemes, which incorporate a hybrid multi-objective utility function that captures the impact of numerical dimension attributes. Our first scheme, Multi-Objective View Recommendation for Data Exploration (MuVE), adopts an incremental evaluation of our multi-objective utility function, which allows pruning of a large number of low-utility views and avoids unnecessary objective evaluations. Our second scheme, upper MuVE (uMuVE), further improves the pruning power by setting the upper bounds on the utility of views and allowing interleaved processing of views, at the expense of increased memory usage. Finally, our third scheme, Memory-aware uMuVE (MuMuVE), provides pruning power close to that of uMuVE, while keeping memory usage within a pre-specified limit.
Autors: Humaira Ehsan;Mohamed A. Sharaf;Panos K. Chrysanthis;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Feb 2018, volume: 30, issue:2, pages: 263 - 277
Publisher: IEEE
 
» Efficient Wideband Computation of Electromagnetic Scattering by Finite Periodic Structures Combining ASED Basis Function With Frequency-Independent Reaction
Abstract:
An efficient wideband electromagnetic scattering analysis method for finite periodic structures by combining the accurate subentire-domain (ASED) basis function with the frequency-independent reaction (FIR) is presented. The ASED basis function is suitable for analyzing finite periodic structures with less unknowns than the conventional method of moments (MoM). Its efficiency is very high. However, it is a single-frequency technique and is still time-consuming for frequency sweep. The FIR can accelerate the frequency sweep, in which the exponential of the Green function is expanded in Taylor series. The impedance element is formulated as the sum of the series, where each term is the product of the geometry-dependent element and the phase factor. Recomputation of the former one is unnecessary during frequency sweep. Thus, it is very efficient. To test the accuracy of the proposed algorithm, several examples are implemented. Numerical results show that the results obtained using the proposed method agree well with those computed using the ASED basis function and conventional MoM. The efficiency of the proposed technique is also validated.
Autors: Ping Du;Gang Zheng;Cheng Wang;Wei Jie Fu;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 234 - 237
Publisher: IEEE
 
» ElasticCore: A Dynamic Heterogeneous Platform With Joint Core and Voltage/Frequency Scaling
Abstract:
Heterogeneous architectures have emerged as a promising solution to address the dark silicon challenge by providing customized cores for each running application. To harness the power of heterogeneity, a critical challenge is simultaneously fine-tuning several parameters at the application, architecture, system, as well as circuit levels for heterogeneous architectures that improve the energy-efficiency envelope. To address this challenge, an ElasticCore platform is described where core resources along with the operating voltage and frequency settings are scaled to match the application behavior at run-time. A quantile linear regression model for power and performance prediction is used to guide the adaptation of the core resources, along with the operating voltage and frequency, to improve the energy efficiency. In addition, the dynamically scalable partitions of the ElasticCore are powered with multiple on-chip voltage regulators with high-power conversion efficiency that are able to realize fast dynamic voltage/frequency scaling. The results indicate that ElasticCore predicts application power and performance behavior with a small error at run-time across all studied benchmarks and achieves, on average close to 93% energy efficiency, as compared to an architecture with the Oracle power and performance predictor.
Autors: Mohammad Khavari Tavana;Mohammad Hossein Hajkazemi;Divya Pathak;Ioannis Savidis;Houman Homayoun;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Feb 2018, volume: 26, issue:2, pages: 249 - 261
Publisher: IEEE
 
» Electrically Small, Low-Profile, Huygens Circularly Polarized Antenna
Abstract:
The design, simulation studies, and experimental verification of an electrically small, low-profile, broadside-radiating Huygens circularly polarized (HCP) antenna are reported. To realize its unique circular polarization cardioid-shaped radiation characteristics in a compact structure, two pairs of the metamaterial-inspired near-field resonant parasitic elements, the Egyptian axe dipole (EAD) and the capacitively loaded loop (CLL), are integrated into a crossed-dipole configuration. The EAD (CLL) elements act as the orthogonal electric dipole (magnetic dipole) radiators. Balanced broadside-radiated electric and magnetic field amplitudes with the requisite 90° phase difference between them are realized by exciting these two pairs of electric and magnetic dipoles with a specially designed, unbalanced crossed-dipole structure. The electrically small (ka = 0.73) design operates at 1575 MHz. It is low profile , and its entire volume is only . A prototype of this optimized HCP antenna system was fabricated, assembled, and tested. The measured results are in good agreement with their simulated values. They demonstrate that the prototype HCP antenna resonates at 1584 MHz with a 0.6 dB axial ratio, and produces the predicted Huygens cardioid-shaped radiation patterns. The measured peak realized LHCP gain was 2.7 dBic, and the associated front-to-back ratio was 17.7 dB.
Autors: Wei Lin;Richard W. Ziolkowski;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 636 - 643
Publisher: IEEE
 
» Electrifying Water Buses: A Case Study on Diesel-to-Electric Conversion in Venice
Abstract:
This study presents the conversion of a diesel-based watercraft for public transportation in Venice, Italy, to an electric propulsion technology, with a view to wide future adoption of electrical transportation. It takes into account energy-storage systems, electrical machines, and drives and examines them in light of economic, environmental, and social issues. Some alternative solutions based on hybrid diesel-electric and full-electric (FE ) powertrains are compared in terms of weight, cost, and payback times. The comparison shows that a hybrid diesel-engine lithium (Li) battery (LB) is the best option for an easy first implementation, even when considering the existing infrastructure.
Autors: Massimo Guarnieri;Mattia Morandin;Antonio Ferrari;Pierpaolo Campostrini;Silverio Bolognani;
Appeared in: IEEE Industry Applications Magazine
Publication date: Feb 2018, volume: 24, issue:1, pages: 71 - 83
Publisher: IEEE
 
» Electron Acceleration and Diffusion in the Gyrophase Space by Low-Frequency Electromagnetic Waves
Abstract:
Charged particle acceleration is a fundamental issue in many fields ranging from particle physics to spacecraft propulsion. In this paper, the interaction between electromagnetic waves and relativistic electrons is numerically studied. The effect of the initial gyrophase in a dipole magnetic field on electron acceleration by wave–particle interaction is found in a test particle code with various wave amplitudes. It is indicated that the initial gyrophase of the electrons plays a crucial role in the acceleration process.
Autors: Hua Huang;Xiao-Tian Gao;Xiao-Gang Wang;Zhi-Bin Wang;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Feb 2018, volume: 46, issue:2, pages: 225 - 229
Publisher: IEEE
 
» Electronic Interface for a Gas Sensor System Based on 32 MHz QCMs: Design and Calibration
Abstract:
This paper describes the design and development of a system of gas sensors based on quartz crystal microbalances (QCMs) to be used for the measurement of gas, vapors, and their mixtures. This system’s architecture manages an array composed of eight QCMs with a resonance frequency of about 32 MHz. Custom oscillator circuits were designed and built to drive the QCMs. A data acquisition stage was developed to collect the output frequencies of the QCMs array and to visualize and store the data. The QCMs have been functionalized with eight different types of anthocyanins, using two different techniques. Three of the QCMs composing the array have been tested, and their performance is compared to a previous array based on 20-MHz QCMs. One of the QCMs, covered via drop casting, when tested in a calibration experiment, shown an improved performance consisting in a ratio of 4.92 between 32- and 20-MHz sensitivities. This number confirmed the ratio of 5.76 theoretically calculated using Sauerbrey’s law. The other two QCMs tested were covered via spray casting, giving resolution of tens of ppb, comparable with the previous release.
Autors: Giorgio Pennazza;Marco Santonico;Alessandro Zompanti;Simone Grasso;Arnaldo D’Amico;
Appeared in: IEEE Sensors Journal
Publication date: Feb 2018, volume: 18, issue:4, pages: 1419 - 1426
Publisher: IEEE
 
» Electronically Tunable Fully Integrated Fractional-Order Resonator
Abstract:
A fully integrated implementation of a parallel fractional-order resonator that employs together a fractional-order capacitor and a fractional-order inductor is proposed in this brief. The design utilizes current-controlled operational transconductance amplifiers as building blocks, designed, and fabricated in AMS CMOS process and based on a second-order approximation of a fractional-order differentiator/integrator magnitude optimized in the range 10 Hz–700 Hz. An attractive benefit of the proposed scheme is its electronic tuning capability.
Autors: Georgia Tsirimokou;Costas Psychalinos;Ahmed S. Elwakil;Khaled N. Salama;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Feb 2018, volume: 65, issue:2, pages: 166 - 170
Publisher: IEEE
 
» Elevating Learner Achievement Using Formative Electronic Lab Assessments in the Engineering Laboratory: A Viable Alternative to Weekly Lab Reports
Abstract:
A laboratory pedagogy interweaving weekly student portfolios with onsite formative electronic laboratory assessments (ELAs) is developed and assessed within the laboratory component of a required core course of the electrical and computer engineering (ECE) undergraduate curriculum. The approach acts to promote student outcomes, and neutralize academic integrity violations, while refocusing instructor and teaching assistant roles toward high-gain instructional activities, such as personalized student tutoring. A mixed-method study evaluated the learning effectiveness and student satisfaction using biweekly ELAs versus traditional laboratory reports in a large-enrollment () undergraduate computer engineering laboratory course. The results of the evaluation indicate statistically significant effects on both learning outcomes and student satisfaction from the use of formative assessments in laboratory delivery, which were corroborated by the instructor’s reflections. Students in the ELA with tutoring enabled delivery cohort performed better on the post-test and were more satisfied with the laboratory assessment design and assistance received in laboratory than those in the control cohort. The findings offer a promising alternative for ECE and engineering laboratory instruction that fosters gains in practical skills and content mastery.
Autors: Baiyun Chen;Ronald F. DeMara;Soheil Salehi;Richard Hartshorne;
Appeared in: IEEE Transactions on Education
Publication date: Feb 2018, volume: 61, issue:1, pages: 1 - 10
Publisher: IEEE
 
» Empirical Model for Electrical Activation of Aluminum- and Boron-Implanted Silicon Carbide
Abstract:
Accurate modeling of the electrical properties of impurities in semiconductors is essential for the mandatory support of the development of novel semiconductor devices by means of simulations. An appropriate modeling approach to determine the activation rate of dopants in silicon carbide is currently not available, which limits the predictability of process simulations. To remedy this fact, we propose an empirical model for the electrical activation of aluminum and boron impurities in silicon carbide for various annealing temperatures and total doping concentrations. The differences of the two acceptor-type dopants are discussed according to the model predictions and the activation ratios for various processing parameters are presented. The model was implemented into Silvaco’s simulation platform Victory Process and evaluated with respect to published experimental findings.
Autors: Vito Šimonka;Andreas Hössinger;Josef Weinbub;Siegfried Selberherr;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 674 - 679
Publisher: IEEE
 
» Employing DC Transmission in Long Distance AC Motor Drives: Analysis of the Copper Economy and Power Losses Reduction in Mining Facilities
Abstract:
High-frequency problems related to pulse-width modulation motor drive systems with long cables are widely discussed in the literature and very harmful to the system components, resulting in motor insulation failures, bearing damage, and electromagnetic interference, among others. As a solution, in a previous work, an alternative system configuration was proposed in which the rectifier and the inverter are separated through a long dc cable, the inverter being located at the motor terminals. Thus, besides the mitigation of all these problems, the proposed topology also features the additional benefit of reducing the cable power losses and the amount of copper required for the power transmission. In this context, this paper evaluates the copper economy obtained through this alternative drive configuration and presents a case study involving real motor drive systems situated in mining plants, whose actual cost of the cables is compared with that of the alternative configuration.
Autors: Vinicius Cardoso de Paula;Hélder de Paula;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 841 - 847
Publisher: IEEE
 
» Enabling a Nationwide Radio Frequency Inventory Using the Spectrum Observatory
Abstract:
Knowledge about active radio transmitters is critical for multiple applications: spectrum regulators can use this information to assign spectrum, licensees can identify spectrum usage patterns and provision their future needs, and dynamic spectrum access applications can efficiently pick operating frequency. To achieve these goals, we need a system that continuously senses and characterizes the radio spectrum. Current measurement systems, however, do not scale over time, frequency and space and cannot perform transmitter detection. We address these challenges with the Spectrum Observatory, an end-to-end system for spectrum measurement and characterization. This paper details the design and integration of the Spectrum Observatory, and describes and evaluates the first unsupervised method for detailed characterization of arbitrary transmitters called TxMiner. We evaluate TxMiner on real-world spectrum measurements collected by the Spectrum Observatory between 30 MHz and 6 GHz and show that it identifies transmitters robustly. Furthermore, we demonstrate the Spectrum Observatory’s capabilities to map the number of active transmitters and their frequency and temporal characteristics, to detect rogue transmitters, and identify opportunities for dynamic spectrum access.
Autors: Mariya Zhivkova Zheleva;Ranveer Chandra;Aakanksha Chowdhery;Paul Garnett;Anoop Gupta;Ashish Kapoor;Matt Valerio;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Feb 2018, volume: 17, issue:2, pages: 362 - 375
Publisher: IEEE
 
» Endocardial Energy Harvesting by Electromagnetic Induction
Abstract:
Objective: cardiac pacemakers require regular medical follow-ups to ensure proper functioning. However, device replacements due to battery depletion are common and account for ∼25% of all implantation procedures. Furthermore, conventional pacemakers require pacemaker leads which are prone to fractures, dislocations or isolation defects. The ensuing surgical interventions increase risks for the patients and costs that need to be avoided. Methods: in this study, we present a method to harvest energy from endocardial heart motions. We developed a novel generator, which converts the heart's mechanical into electrical energy by electromagnetic induction. A mathematical model has been introduced to identify design parameters strongly related to the energy conversion efficiency of heart motions and fit the geometrical constraints for a miniaturized transcatheter deployable device. The implemented final design was tested on the bench and in vivo. Results : the mathematical model proved an accurate method to estimate the harvested energy. For three previously recorded heart motions, the model predicted a mean output power of 14.5, 41.9, and 16.9 μW. During an animal experiment, the implanted device harvested a mean output power of 0.78 and 1.7 μW at a heart rate of 84 and 160 bpm, respectively. Conclusion: harvesting kinetic energy from endocardial motions seems feasible. Implanted at an energetically favorable location, such systems might become a welcome alternative to extend the lifetime of cardiac implantable electronic device. Significance: the presented endocardial energy harvesting concept has the potential to turn pacemakers into battery- and leadless systems and thereby eliminate two major drawbacks of contemporary systems.
Autors: Adrian Zurbuchen;Andreas Haeberlin;Lukas Bereuter;Alois Pfenniger;Simon Bosshard;Micha Kernen;Paul Philipp Heinisch;Juerg Fuhrer;Rolf Vogel;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Feb 2018, volume: 65, issue:2, pages: 424 - 430
Publisher: IEEE
 
» Ends and Means
Abstract:
Even the smallest coding mistake can cause huge problems when it slips by testing. Finding it can be difficult, and retesting the fixed system can be expensive, but this certainly isn't true for every type of problem. A defect found and fixed during coding is a fairly routine occurrence and not costlier than a defect found and fixed during design. Quite the opposite is usually true.
Autors: Gerard J. Holzmann;
Appeared in: IEEE Software
Publication date: Feb 2018, volume: 35, issue:1, pages: 14 - 17
Publisher: IEEE
 
» Energy Consumption Enhancement of Reverse-Biased Silicon-Based Mach–Zehnder Modulators Using Corrugated Slow Light Waveguides
Abstract:
The energy efficiency of silicon modulators can be enhanced by increasing the doping level. As an alternative solution, slow light modulators based on corrugated waveguides can also be used for improving the energy efficiency. Using numerical and analytical tools, we show that for the same level of energy consumption reduction, the loss coefficient and the loss-modulation efficiency for the slow-light modulators are smaller than those for the modulators with an increased doping level. It is shown that the slow light structures with medium slow down factors (specifically slowdown factors of less than 6) can be reasonable candidates for enhancing the modulator's energy efficiency. For example, an energy consumption of less than 100 fJ/bit can be achieved at a slow-down factor of 6, using a doping level of 5 × 1017 cm-3 for acceptors and 1 × 1018 cm-3 for donors.
Autors: Reza Hosseini;Levon Mirzoyan;Kambiz Jamshidi;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 7
Publisher: IEEE
 
» Energy Efficiency in Cache-Enabled Small Cell Networks With Adaptive User Clustering
Abstract:
Using a network of cache enabled small cells, traffic during peak hours can be reduced by proactively fetching the content that is most likely to be requested. In this paper, we aim to explore the impact of proactive caching on an important metric for future generation networks, namely, energy efficiency (EE). We argue that, exploiting the spatial repartitions of users in addition to the correlation in their content popularity profiles, can result in considerable improvement of the achievable EE. In this paper, the optimization of EE is decoupled into two related subproblems. The first one addresses the issue of content popularity modeling. While most existing works assume similar popularity profiles for all users, we consider an alternative framework in which, users are clustered according to their popularity profiles. In order to showcase the utility of the proposed clustering, we use a statistical model selection criterion, namely, Akaike information criterion. Using stochastic geometry, we derive a closed-form expression of the achievable EE and we find the optimal active small cell density vector that maximizes it. The second subproblem investigates the impact of exploiting the spatial repartitions of users. After considering a snapshot of the network, we formulate a combinatorial problem that optimizes content placement in order to minimize the transmission power. Numerical results show that the clustering scheme considerably improves the cache hit probability and consequently the EE, compared with an unclustered approach. Simulations also show that the small base station allocation algorithm improves the energy efficiency and hit probability.
Autors: Salah Eddine Hajri;Mohamad Assaad;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 955 - 968
Publisher: IEEE
 
» Energy-Efficient and Distributed Network Management Cost Minimization in Opportunistic Wireless Body Area Networks
Abstract:
Mobility induced by limb/body movements in Wireless Body Area Networks (WBANs) significantly affects the link-quality of intra-BAN and inter-BAN communication units, which, in turn, affects the Quality-of-Service (QoS) of each WBAN, in terms of reliability, efficient data transmission and network throughput guarantees. Further, the variation in link-quality between WBANs and Access Points (APs) makes the WBAN-equipped patients more resource-constrained in nature, which also increases the data dissemination delay. Therefore, to minimize the data dissemination delay of the network, WBANs send patients’ physiological data to local servers using the proposed opportunistic transient connectivity establishment algorithm. Additionally, limb/body movements induce dynamic changes to the on-body network topology, which, in turn, increases the network management cost and decreases the life-time of the sensor nodes periodically. Also, mutual and cross technology interference among coexisting WBANs and other radio technologies increases the energy consumption rate of the sensor nodes and also the energy management cost. To address the problem of increased network management cost and data dissemination delay, we propose a network management cost minimization framework to optimize the network throughput and QoS of each WBAN. The proposed framework attempts to minimize the dynamic connectivity, interference management, and data dissemination costs for opportunistic WBAN. We have, theoretically, analyzed the performance of the proposed framework to provide reliable data transmission in opportunistic WBANs. Simulation results show significant improvement in the network performance compared to the existing solutions.
Autors: Amit Samanta;Sudip Misra;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Feb 2018, volume: 17, issue:2, pages: 376 - 389
Publisher: IEEE
 
» Energy-Efficient Sensor Data Collection Approach for Industrial Process Monitoring
Abstract:
The use of wireless sensor network for industrial applications has attracted much attention from both academic and industrial sectors. It enables a continuous monitoring, controlling, and analyzing of the industrial processes, and contributes significantly to finding the best performance of operations. Sensors are typically deployed to gather data from the industrial environment and to transmit it periodically to the end user. Since the sensors are resource constrained, effective energy management should include new data collection techniques for an efficient utilization of the sensors. In this paper, we propose adaptive data collection mechanisms that allow each sensor node to adjust its sampling rate to the variation of its environment, while at the same time optimizing its energy consumption. We provide and compare three different data collection techniques. The first one uses the analysis of data variances via statistical tests to adapt the sampling rate, whereas the second one is based on the set-similarity functions, and the third one on the distance functions. Both simulation and real experimentations on telosB motes were performed in order to evaluate the performance of our techniques. The obtained results proved that our proposed adaptive data collection methods can reduce the number of acquired samples up to 80% with respect to a traditional fixed-rate technique. Furthermore, our experimental results showed significant energy savings and high accurate data collection compared to existing approaches.
Autors: Hassan Harb;Abdallah Makhoul;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Feb 2018, volume: 14, issue:2, pages: 661 - 672
Publisher: IEEE
 
» Engineering the Structural Nonlinearity Using Multimodal-Shaped Springs in MEMS
Abstract:
The purpose of this paper is to introduce a novel technique to engineer in a precise way the structural nonlinearity in MEMS springs. To perform the adjustment of structural nonlinearity, the idea of using a sine-shaped beam following the combination of the natural bending modes of a straight one is explored to create a multimodal-shaped spring. The basic analytical model of multimodal beam bending is introduced and validated with finite element modeling. Proposed multimodal springs are fabricated by deep reactive ion etching on silicon on insulator wafer and their force-displacement characteristics are extracted using a force probe, with the resulting curves being close to the ones predicted by the theoretical calculations. The presented spring allows the engineering of structural nonlinearity by varying the amplitudes of the different modes used as initial shape. Thus, a straightforward method to create any type of structural nonlinearity starting from fully bistable up to the linear case, without the need to combine springs of several types, reducing the complexity of the targeted systems and their footprint. The proposed methodology was used to successfully design a suspension spring that exhibits flat force-displacement region with the aim to increase the bandwidth of vibrational energy harvesters. [2017-0250]
Autors: Bogdan Vysotskyi;Fabien Parrain;Denis Aubry;Philippe Gaucher;Xavier Le Roux;Elie Lefeuvre;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Feb 2018, volume: 27, issue:1, pages: 40 - 46
Publisher: IEEE
 
» Enhance In-Hand Dexterous Micromanipulation by Exploiting Adhesion Forces
Abstract:
Micromanipulation plays a key role in the development of complex and assembled microsystems. However, current micromanipulation solutions are often limited to small rotation amplitudes and to simple shaped objects (such as cubes). Our approach consists of developing in-hand micromanipulation techniques using dexterous microhands to manipulate arbitrary shaped objects and to perform large rotations. This paper focuses on the trajectory generation of a dexterous microhand to achieve automated repositioning by taking advantage of adhesion forces. The results on the generated trajectories show that adhesion forces can be exploited to enhance the manipulation possibilities. Moreover, experiments show that planed rotations are performed at more than using an open-loop control. Dexterous micromanipulation is a promising way to perform complex manipulation tasks in microscale.
Autors: Jean-Antoine Seon;Redwan Dahmouche;Michaël Gauthier;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 113 - 125
Publisher: IEEE
 
» Enhanced Electrical Performance and Negative Bias Illumination Stability of Solution-Processed InZnO Thin-Film Transistor by Boron Addition
Abstract:
In this paper, boron-doped indium–zinc–oxide (InZnO) thin-film transistors (BIZO TFTs) were fabricated by solution process. The electrical performance and stability under the negative bias illumination stress (NBIS) have been greatly improved by B doping. The BIZO TFT with 5 mol.% B doping ratio shows a superior electrical performance with a field-effect mobility of 10.15 cm2/, a threshold voltage of 3.29 V, a subthreshold swing of 0.35 V/decade, and an ON/OFF ratio of 108. Furthermore, the 5 mol.% BIZO TFT shows only a −1.59 V shift of the threshold voltage, compared with a large negative shift of −4.24 V for pure IZO TFTs. The enhancement of electrical performance and stability under NBIS is due to the reduction of oxygen vacancies, which are suppressed by B doping. The density of states is calculated to further validate the improved electrical performance and NBIS stability of BIZO TFTs.
Autors: De-Yao Zhong;Jun Li;Cheng-Yu Zhao;Chuan-Xin Huang;Jiang-Hua Zhang;Xi-Feng Li;Xue-Yin Jiang;Zhi-Lin Zhang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 520 - 525
Publisher: IEEE
 
» Enhanced Hydrated Lime—A Simple Solution for Acid Gas Compliance
Abstract:
The U.S. landscape of environmental regulations is complex and continues to evolve requiring more stringent acid gas emission limits than ever. Current regulations include acid gas emission requirements via the Portland Cement National Emission Standard for Hazardous Air Pollutants, consent decrees, and revised operating permits, where operational modifications are made requiring additional acid gas removal. As a result of the need to comply with these increasingly stringent acid gas emission limits, there is a growing desire for a relatively simple solution. Dry sorbent injection (DSI) technology offers a low capital cost solution with a relatively small equipment footprint, low power consumption, and ease of retrofit to a majority of existing facilities. As DSI technology has matured, the systems have become more reliable and advancements in calcium based sorbents have provided new compliance solutions that were not available in past years. The optimization of the physical properties of enhanced hydrated lime products has demonstrated upward of 90% sulfur dioxide and 95+% hydrochloric acid reduction with the DSI technology over a range of applications, and has been consistently successful achieving cement plant's acid gas removal needs to meet their regulatory requirements.
Autors: Gerald Hunt;Johan J. Heiszwolf;Melissa Sewell;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 796 - 807
Publisher: IEEE
 
» Enhanced Model and Real-Time Simulation Architecture for Modular Multilevel Converter
Abstract:
This paper presents i) an equivalent model of the half-bridge modular multilevel converter (HB-MMC) which is suitable for real-time applications, ii) a hybrid central-processing unit/field-programmable gate array (CPU/FPGA)-based architecture for real-time simulation of electromagnetic transients of systems which include HB-MMC, and iii) a novel arrangement for sorting results referred to as the “sub-module (SM) rank list”, which tackles the bottleneck for parallel implementation of the MMC arm model solver on the FPGA. The Adam–Bashforth (AB) method is used for numerical integration of the HB-SM capacitor model. The second-order AB method provides a constant admittance matrix of the HB-MMC and, thus, reduces computational burden while offering the same accuracy as that of the widely used Trapezoidal method. The CPU/FPGA-based architecture is optimized to obtain maximum parallelism of the HB-MMC model implementation, adopting a standard, single-precision, floating-point computational engine. The proposed sorting arrangement is independent of the utilized sorting algorithm and its application to the odd–even bubble sorting scheme is presented in this paper. The proposed architecture offers a simulation time-step of 825 ns while including the sorting module as the SM capacitor voltage-balancing control unit. This enables accurate analysis of MMC controls based on either software-in-the-loop or hardware-in-the-loop approaches. Performance and accuracy of the MMC model and the hybrid CPU/FPGA-based architecture are evaluated based on a set of case studies on a 401-level HB-MMC-based HVDC station and verified based on offline simulation results in the PSCAD/EMTDC environment.
Autors: Mojtaba Ashourloo;Ramin Mirzahosseini;Reza Iravani;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 466 - 476
Publisher: IEEE
 
» Enhancement of a Continuous Liquid Level Sensor Based on a Macro-Bend Polymer Optical Fiber Coupler
Abstract:
An approach to improve the side-coupling ratio of the macro-bend polymer optical fiber (POF) coupler is proposed in this paper. Two naked POFs are twisted and twined around a cylinder to achieve continuous liquid level sensing. Through filling the gap between the two twisted POFs with UV optical cement, both the sensitivity and the measurement range are increased substantially. The reversibility is also improved since the gap is eliminated, and little liquid can exist in the structure with the liquid level decreasing. The design turns out to be a good method to enhance the performance, and could also be applied in the displacement or stress sensing field.
Autors: Yingzi Zhang;Yulong Hou;Yanjun Zhang;Yanjun Hu;Liang Zhang;Xiaolong Gao;Huixin Zhang;Wenyi Liu;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 6
Publisher: IEEE
 
» Enhancement of Intercellular Electrical Synchronization by Conductive Materials in Cardiac Tissue Engineering
Abstract:
Objective: cardiac tissue regeneration for the treatment of cardiovascular diseases has been of great research interest. Under the hypothesis that electrical synchronization of cardiac cells can be aided by conductive materials, electrically conductive scaffolds have been frequently used to improve cardiac tissue regeneration. However, theoretical analysis is presently absent in examining the underlying mechanism and rationally guiding the design of these conductive scaffolds. Methods: here, equivalent-circuit models are proposed, in which two adjacent groups of cardiomyocytes are grown either on a bulk conductive substrate or around conductive nanostructures. When one group of cells leads with action potentials, the membrane depolarization of the following group is investigated. Results: this study reveals that membrane depolarization of the following group is most sensitive to seal resistance to the substrate while surface roughness and conductivity of the material have less influence. In addition, it is found that a multiple-cell group is easier to be depolarized by its adjacent beating cardiomyocytes. For nanostructure-bridged cardiac cells, substantial depolarization occurs only with a seal resistance larger than 1013 Ω/sqr, which is contradictory to many reported estimations. Conclusion: this work theoretically confirms the positive role of conductive scaffolds and nanostructures in aiding electrical synchronization of cardiac cells and reveals that its performance mainly relies on the cell-device interface. Significance: this work provides a theoretical basis for the rational design of electroactive scaffolds for enhanced cardiac tissue engineering.
Autors: Yu Wu;Liang Guo;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Feb 2018, volume: 65, issue:2, pages: 264 - 272
Publisher: IEEE
 
» Enhancing Selectivity in Big Data
Abstract:
Today’s companies collect immense amounts of personal data and enable wide access to it within the company. This exposes the data to external hackers and privacy-transgressing employees. This study shows that, for a wide and important class of workloads, only a fraction of the data is needed to approach state-of-the-art accuracy. We propose selective data systems that are designed to pinpoint the data that is valuable for a company’s current and evolving workloads. These systems limit data exposure by setting aside the data that is not truly valuable.
Autors: Mathias Lecuyer;Riley Spahn;Roxana Geambasu;Tzu-Kuo Huang;Siddhartha Sen;
Appeared in: IEEE Security & Privacy
Publication date: Feb 2018, volume: 16, issue:1, pages: 34 - 42
Publisher: IEEE
 
» Enhancing the Student Learning Experience in Software Engineering Project Courses
Abstract:
Carrying out real-world software projects in their academic studies helps students to understand what they will face in industry, and to experience first-hand the challenges involved when working collaboratively. Most of the instructional strategies used to help students take advantage of these activities focus on supporting agile programming, which is appropriate for capstone courses. This is not always recommended in initial software engineering project courses, however, where novice developers run projects in teams while simultaneously taking other courses. To enhance the learning and teamwork experience in this latter instructional scenario, this paper proposes a formative monitoring method, reflexive weekly monitoring (RWM), for use in project courses that involve disciplined software processes and loosely coupled work. RWM uses self-reflection and collaborative learning practices to help students be aware of their individual and team performance. RWM was applied in a case study over nine consecutive semesters. The results obtained indicate that RWM was effective in enhancing the learning experience in the instructional scenario studied. While students in the monitored teams were more effective and coordinated, and experienced a higher sense of team belonging and satisfaction, little evidence was found of them being more productive than students working in non-monitored teams.
Autors: Maíra Marques;Sergio F. Ochoa;María Cecilia Bastarrica;Francisco J. Gutierrez;
Appeared in: IEEE Transactions on Education
Publication date: Feb 2018, volume: 61, issue:1, pages: 63 - 73
Publisher: IEEE
 
» Ensemble of ESA/AATSR Aerosol Optical Depth Products Based on the Likelihood Estimate Method With Uncertainties
Abstract:
Within the European Space Agency Climate Change Initiative (CCI) project Aerosol_cci, there are three aerosol optical depth (AOD) data sets of Advanced Along-Track Scanning Radiometer (AATSR) data. These are obtained using the ATSR-2/ATSR dual-view aerosol retrieval algorithm (ADV) by the Finnish Meteorological Institute, the Oxford-Rutherford Appleton Laboratory (RAL) Retrieval of Aerosol and Cloud (ORAC) algorithm by the University of Oxford/RAL, and the Swansea algorithm (SU) by the University of Swansea. The three AOD data sets vary widely. Each has unique characteristics: the spatial coverage of ORAC is greater, but the accuracy of ADV and SU is higher, so none is significantly better than the others, and each has shortcomings that limit the scope of its application. To address this, we propose a method for converging these three products to create a single data set with higher spatial coverage and better accuracy. The fusion algorithm consists of three parts: the first part is to remove the systematic errors; the second part is to calculate the uncertainty and fusion of data sets using the maximum likelihood estimate method; and the third part is to mask outliers with a threshold of 0.12. The ensemble AOD results show that the spatial coverage of fused data set after mask is 148%, 13%, and 181% higher than those of ADV, ORAC, and SU, respectively, and the root-mean-square error, mean absolute error, mean bias error, and relative mean bias are superior to those of the three original data sets. Thus, the accuracy and spatial coverage of the fused AOD data set masked with a threshold of 0.12 are improved compared to the original data set. Finally, we discuss the selection of mask thresholds.
Autors: Yanqing Xie;Yong Xue;Yahui Che;Jie Guang;Linlu Mei;Dave Voorhis;Cheng Fan;Lu She;Hui Xu;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 997 - 1007
Publisher: IEEE
 
» Equivalent Circuit of the Neuro-Electronic Junction for Signal Recordings From Planar and Engulfed Micro-Nano-Electrodes
Abstract:
In the latest years, several attempts to develop extracellular microtransducers to record electrophysiological activity of excitable cells have been done. In particular, many efforts have been oriented to increase the coupling conditions, and, thus, improving the quality of the recorded signal. Gold mushroom-shaped microelectrodes (GMμE) are an example of nano-devices to achieve those requirements. In this study, we developed an equivalent electrical circuit of the neuron–microelectrode system interface to simulate signal recordings from both planar and engulfed micro-nano-electrodes. To this purpose, models of the neuron, planar, gold planar microelectrode, and GMμE, neuro-electronic junction (microelectrode–electrolyte interface, cleft effect, and protein-glycocalyx electric double layer) are presented. Then, neuronal electrical activity is simulated by Hspice software, and analyzed as a function of the most sensitive biophysical models parameters, such as the neuron–microelectrode cleft width, spreading and seal resistances, ion-channel densities, double-layer properties, and microelectrode geometries. Results are referenced to the experimentally recorded electrophysiological neuronal signals reported in the literature.
Autors: Giuseppe Massobrio;Sergio Martinoia;Paolo Massobrio;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Feb 2018, volume: 12, issue:1, pages: 3 - 12
Publisher: IEEE
 
» Ergodic Rate of Millimeter Wave Ad Hoc Networks
Abstract:
In this paper, we use a stochastic geometry approach to quantify the ergodic rate of each user in an outdoor mm-wave ad hoc network. For a variety of use cases, it is reasonable to assume users will be clustered around a central point (e.g., WiFi hotspot or clusterhead) rather than uniformly distributed. Our results indicate that, in contrast to sub-6-GHz networks, clustered mm-wave ad hoc networks tolerate the increased interference because directional antenna arrays reduce the interference. For certain antenna array configurations and user densities, uncoordinated users within a cluster outperform TDMA. Additionally, we derive a scaling law for uniform mm-wave ad hoc networks and propose a heuristic scaling for clustered networks. The per user ergodic rate remains constant if mm-wave antenna arrays scale sub-linearly with the number of users for uniform networks or linearly in clustered networks as users are added to the cluster. Last, we compute expressions that quantify the loss in ergodic rate per user when alignment error occurs at the receiver and transmitter. Our results show that even relatively small errors in alignment can lead to significant ergodic rate reduction.
Autors: Andrew Thornburg;Robert W. Heath;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 914 - 926
Publisher: IEEE
 
» Estimating the specific heat capacity and heating of electronic sensors and devices
Abstract:
Most sensors have three functional parts: the sensor part, signal conditioning part and interface part (Fig. 1). The sensor part senses the physical phenomena and transforms it typically into electric form. The signal condition part amplifies, linearizes and scales the electric signal. The interface part can be a simple mechanical connector, (field) bus adapter or in a wireless sensor, a radio module. Signal conditioning and interface parts are in most cases implemented by electronics.
Autors: Ilkka Korhonen;Jero Ahola;
Appeared in: IEEE Instrumentation & Measurement Magazine
Publication date: Feb 2018, volume: 21, issue:1, pages: 54 - 62
Publisher: IEEE
 
» Evaluation of DC Collector-Grid Configurations for Large Photovoltaic Parks
Abstract:
This paper presents a detailed comparison between the conventional ac collector-grid configuration and two proposed dc collector-grid configurations for large photovoltaic (PV) parks. One complete year of measured weather data at two different locations, one very sunny and the other with relatively less sun, is used for the evaluation. An already validated PV performance model is used to estimate the expected energy yield of the PV park for the given environmental and connection conditions. Loss mechanisms in different grid components in the three configurations are discussed based on the developed models. These components include the inverters, transformers, cables, and dc–dc converters. A comparison of the total losses in these components helps to identify the configuration that has the potential to operate at higher efficiency and, hence, generate maximum revenue. The economic viability metrics are calculated and a sensitivity analysis is carried out using the Monte Carlo method with a uncertainty in the considered cost and energy yield parameters.
Autors: Hafiz Abu Bakar Siddique;Rik W. De Doncker;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 311 - 320
Publisher: IEEE
 
» Evaluation of Local Error Estimators for the RWG-Based EFIE
Abstract:
Several error estimators suitable for use with the adaptive refinement solution of the electric field integral equation (EFIE) are investigated. The estimators are evaluated using a series of test problems for which correlation coefficients and scatter plots are computed. In addition, two new discontinuity estimators are introduced based on the combination of the charge discontinuity with the current or current discontinuity. The evaluations show that simple discontinuity estimators are as accurate for adaptive refinement as the EFIE residual estimator, and are far more computationally efficient.
Autors: Sang Kyu Kim;Andrew F. Peterson;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 819 - 826
Publisher: IEEE
 
» Evaluation of Parallel Level Sets and Bowsher’s Method as Segmentation-Free Anatomical Priors for Time-of-Flight PET Reconstruction
Abstract:
In this article, we evaluate Parallel Level Sets (PLS) and Bowsher’s method as segmentation-free anatomical priors for regularized brain positron emission tomography (PET) reconstruction. We derive the proximity operators for two PLS priors and use the EM-TV algorithm in combination with the first order primal-dual algorithm by Chambolle and Pock to solve the non-smooth optimization problem for PET reconstruction with PLS regularization. In addition, we compare the performance of two PLS versions against the symmetric and asymmetric Bowsher priors with quadratic and relative difference penalty function. For this aim, we first evaluate reconstructions of 30 noise realizations of simulated PET data derived from a real hybrid positron emission tomography/magnetic resonance imaging (PET/MR) acquisition in terms of regional bias and noise. Second, we evaluate reconstructions of a real brain PET/MR data set acquired on a GE Signa time-of-flight PET/MR in a similar way. The reconstructions of simulated and real 3D PET/MR data show that all priors were superior to post-smoothed maximum likelihood expectation maximization with ordered subsets (OSEM) in terms of bias-noise characteristics in different regions of interest where the PET uptake follows anatomical boundaries. Our implementation of the asymmetric Bowsher prior showed slightly superior performance compared with the two versions of PLS and the symmetric Bowsher prior. At very high regularization weights, all investigated anatomical priors suffer from the transfer of non-shared gradients.
Autors: Georg Schramm;Martin Holler;Ahmadreza Rezaei;Kathleen Vunckx;Florian Knoll;Kristian Bredies;Fernando Boada;Johan Nuyts;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Feb 2018, volume: 37, issue:2, pages: 590 - 603
Publisher: IEEE
 
» Evaluation of the Potential of Dipole Field Navigation for the Targeted Delivery of Therapeutic Agents in a Human Vascular Network
Abstract:
Magnetically guided agents in the vascular network are expected to enable the targeted delivery of therapeutics to localized regions while avoiding their systemic circulation. Due to the small size of the medically applicable superparamagnetic microscale agents required to reach the smaller arteries, high magnetic fields and gradients are required to reach saturation magnetization and generate sufficient directional forces, respectively, for their effective navigation in the vascular environment. Currently, the only method that provides both a high field and high magnetic gradient strengths in deep tissues at the human scale is known as dipole field navigation (DFN). This method relies on the controlled distortion of the field inside a magnetic resonance imaging scanner by precisely positioning ferromagnetic cores around the patient. This paper builds on previous works that have experimentally demonstrated the feasibility of the method and proposed optimization algorithms for placing the cores. The maximum gradient strengths that can be generated for single and multibifurcation vascular routes are investigated while considering the major constraints on core positions (limited space in the scanner, magnetic interactions). Using disc cores, which were previously shown particularly effective for the DFN, results show that gradient strengths exceeding 400 mT/m (a tenfold increase with respect to typical gradients generated by clinical MRI scanners) can be achieved at 10 cm inside the patient, but decrease as the complexity of the vascular route increases. The potential of the method is evaluated for targeting regions of a vascular model of a human liver, segmented from clinical data, with encouraging results showing strengths up to 150 mT/m for generating gradients at three consecutive bifurcations within 20° of average gradient direction error.
Autors: Maxime Latulippe;Sylvain Martel;
Appeared in: IEEE Transactions on Magnetics
Publication date: Feb 2018, volume: 54, issue:2, pages: 1 - 12
Publisher: IEEE
 
» Evaluation of the Role of Deep Trap State Using Analytical Model in the Program/Erase Cycling of NAND Flash Memory and Its Process Dependence
Abstract:
A method to analyze the kinetics of the charge accumulation in the tunnel oxide by the nand flash memory program and erase (P/E) cycling is proposed. Both electron trapping and detrapping processes are required to be considered owing to the oxide high electric field during P/E cycles. Consequently, the electron trapping in the deep trap state is concluded, whose trap energy () is more than 3.5 eV. Furthermore, the as-grown trap state density (), the trapping capture cross section (), and the number of trapped positive charges can also be extracted to explain the tunneling current modulation and the shift by oxide-trapped charges under the P/E stress. The trapped electrons are mainly distributed in the center of tunnel oxide, and the distributed area extends as the P/E bias increases. In addition, the dependence of oxidation process is also shown. Both thermal dry and plasma oxidation have almost the same value of ( cm2). However, 30% reduction of is shown in plasma oxidation ( cm−3) when compared with thermal dry oxidation ( cm−3).
Autors: Bo-Jun Yang;Yu-Ting Wu;Yung-Yueh Chiu;Tse-Mien Kuo;Jung-Ho Chang;Pin-Yao Wang;Riichiro Shirota;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 499 - 506
Publisher: IEEE
 
» Evaluations of a Class of Integrals That Arise in Wave Scattering Problems by Using the Taylor Product Theorem
Abstract:
Taylor product theorem is applied to the evaluation of a class of integrals that arise in high-frequency wave scattering problems. We expand a term under the integral into exponentiated powers of that are suitable for term-by-term integrations. We utilize the expansion in an example and make accuracy and speed analysis.
Autors: Ali Uzer;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 1031 - 1034
Publisher: IEEE
 
» Event-Based Model Predictive Tracking Control of Nonholonomic Systems With Coupled Input Constraint and Bounded Disturbances
Abstract:
This paper studies the event-based model predictive control (EMPC) for tracking of nonholonomic mobile robot with coupled input constraint and bounded disturbances. First, an event-triggering mechanism is presented by designing a threshold for the error between the actual trajectory and the predicted one, aiming at reducing the computational load. Second, a model predictive control strategy is developed based on the event-triggering mechanism. Recursive feasibility is guaranteed by designing a robust terminal region and the proper parameters. We show that the tracking system is practically stable and also provides a convergence region for the tracking error. The convergence region indicates that the tracking performance is negatively related to the minimal interevent time as well as the bound of the disturbances. Finally, simulation results show that the computation load is significantly reduced and illustrate the efficiency of our proposed strategy.
Autors: Zhongqi Sun;Li Dai;Yuanqing Xia;Kun Liu;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Feb 2018, volume: 63, issue:2, pages: 608 - 615
Publisher: IEEE
 
» Event-Triggered Protocol for the Consensus of Multi-Agent Systems With State-Dependent Nonlinear Coupling
Abstract:
This paper proposes an event-triggered protocol to achieve consensus in multi-agent system, in which neighboring agents are coupled via a nonlinear function with local passivity. It is mathematically proved that the proposed protocol guarantees average consensus in the system, excluding the existence of Zeno phenomenon. As a practical application, the scheme is applied to achieve synchronization in the Kuramoto oscillator network. Phase agreement is obtained for oscillators with identical natural frequency. For oscillators with non-identical natural frequencies, their phases are confined in a bounded range and their frequencies reach an average of their natural frequencies. To further demonstrate the generality of the scheme, another multi-agent system with coupling based on exponential and tangent functions is also presented. All the simulation results verify the condition of consensus and confirm the effectiveness of the scheme.
Autors: Qiang Jia;Wallace K. S. Tang;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 723 - 732
Publisher: IEEE
 
» Evidence of Variabilities in EEG Dynamics During Motor Imagery-Based Multiclass Brain–Computer Interface
Abstract:
Inter-subject and inter-session variabilities pose a significant challenge in electroencephalogram (EEG)-based brain–computer interface (BCI) systems. Furthermore, high dimensional EEG montages introduce huge computational burden due to excessive number of channels involved. Two experimental, i.e., inter-session and inter-subject, variabilities of EEG dynamics during motor imagery (MI) tasks are investigated in this paper. In particular, the effect on the performance of the BCIs due to day-to-day variability in EEG dynamics during the alterations in cognitive stages is explored. In addition, the inter-subject BCIs feasibility between cortically synchronized and desynchronized subject pairs on pairwise performance associativity is further examined. Moreover, the consequences of integrating spatial brain dynamics of varying the number of channels - from specific regions of the brain - are also discussed in case of both the contexts. The proposed approach is validated on real BCI data set containing EEG data from four classes of MI tasks, i.e., left/right hand, both feet, and tongue, subjected prior to a preprocessing of three different spatial filtering techniques. Experimental results have shown that a maximum classification accuracy of around 58% was achieved for the inter-subject experimental case, whereas a 31% deviation was noticed in the classification accuracies across two sessions during the inter-session experimental case. In conclusion, BCIs, without the subject-and session-specific calibration and with lesser number of channels employed, play a vital role while promoting a generic and efficient framework for plug and play use.
Autors: Simanto Saha;Khawza Iftekhar Uddin Ahmed;Raqibul Mostafa;Leontios Hadjileontiadis;Ahsan Khandoker;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Feb 2018, volume: 26, issue:2, pages: 371 - 382
Publisher: IEEE
 
» Evolution of Global Product Development Networks: An Exploratory Study
Abstract:
Global Product Development (GPD) networks have evolved to satisfy the unique requirements essential to the successful adoption of corporate outsourcing and offshoring during development processes. Having reviewed the relevant literature associated with GPD, this paper seeks to contribute to the understanding of organizational considerations taken by GPD networks during their transitional processes. A retrospective case study analysis was conducted with 17 Italian companies classified into six GPD configurations (named the “Chess matrix”). Each classification was based on both developmental localization (local versus global) and product development process fragmentation; development activities are either entirely performed within the same development lab, eventually with the contribution of support/adaptive units, or they are split among development units. Using this classification system, an evolutionary model was adopted to illustrate the dynamic paths companies follow when transitioning toward new GPD configurations. With this framework and categorization process, it was deduced that three main variables drove each of the 17 companies: 1) market needs; 2) market extension; and 3) internal needs. These variables were determined based on the GPD approach each company adopted in pursuit of a stable profitable configuration that was achieved by either deliberately remaining in a certain configuration or by employing an evolutionary GPD development configuration. In recognizing that there is not a singularly optimal stable configuration, it is essential to recognize and identify the individual drivers being pursued by each enterprise when implementing specific configurations. Further research will be devoted to more extensively elaborate the paths within a larger sample of companies to identify unrevealed paths and drivers that move companies in their product development globalization efforts.
Autors: Margherita Pero;Monica Rossi;Sergio Terzi;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Feb 2018, volume: 65, issue:1, pages: 34 - 45
Publisher: IEEE
 
» Evolutionary Stability of Reputation-Based Incentive Mechanisms in P2P Systems
Abstract:
Free riding is a severe problem in P2P systems. Although many incentive mechanisms based on reputation have been proposed to mitigate problem of free riding, reputation management fails to evolve as an evolutionary stable strategy (ESS) due to cost involved in keeping track of reputation. We prove that a system setting with one time entry fee, imposed on new comers and distributed among the peers that calculate reputation, makes reputation-based resource allocation an ESS. Then, we simulate the system model using evolutionary dynamics for its performance evaluation.
Autors: Antriksh Goswami;Gopal Sharan Parashari;Ruchir Gupta;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 268 - 271
Publisher: IEEE
 
» Exact Bit Error Rate Analysis for Color Shift Keying Modulation
Abstract:
In this letter, we present a new method to derive the exact analytical expression for the bit error rate (BER) of the color shift keying (CSK) modulation scheme over additive white Gaussian noise channel. We first exploit the coplanarity of CSK symbols, and build up a 2-D graphically symmetric space to simplify the BER analysis in the 3-D space of the signal transmitted via the red, green, and blue light beams. Thanks to the graphical symmetry of the symbols in the 2-D space, the symbol transition probabilities can be evaluated with less complexity. Then, with the aid of decision region partitioning, the exact symbol transition probabilities can be calculated. At last, the exact BER can be obtained by the weighted sum of all the symbol transition probabilities with the corresponding Hamming distances. Simulations are performed, and the results demonstrate that our presented BER analysis achieves more exact performance evaluation in both high and low signal-to-noise ratio regimes than the counterparts in other papers.
Autors: Jian Tang;Lin Zhang;Zhiqiang Wu;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 284 - 287
Publisher: IEEE
 
» Exact Calculation of Noise Maps and ${g}$ -Factor in GRAPPA Using a ${k}$ -Space Analysis
Abstract:
Characterization of the noise distribution in magnetic resonance images has multiple applications, including quality assurance and protocol optimization. Noise characterization is particularly important in the presence of parallel imaging acceleration with multi-coil acquisitions, where the noise distribution can contain severe spatial heterogeneities. If the parallel imaging reconstruction is a linear process, an accurate noise analysis can be carried out by taking into account the correlations between all the samples involved. However, for -space-based techniques such as generalized autocalibrating partially parallel acquisition (GRAPPA), the exact analysis has been considered computationally prohibitive due to the very large size of the noise covariance matrices required to characterize the noise propagation from -space to image space. Previously proposed methods avoid this computational burden by formulating the GRAPPA reconstruction as a pixel-wise linear operation performed in the image space. However, these methods are not exact in the presence of non-uniform sampling of -space (e.g., containing a calibration region). For this reason, in this paper, we develop an accurate characterization of the noise distribution for self-calibrated parallel imaging in the presence of arbitrary Cartesian sampling patterns. By exploiting the symmetries and separability in the noise propagation process, the proposed method is computationally efficient and does not require large matrices. Under the assumption of a fixed reconstruction kernel, this method provides the precise distribution of the noise variance for each coil’s image. These coil-by-coil noise maps are subsequently combined according to the coil combination approach- used in image reconstruction, and therefore can be applied with both complex coil combination and root-sum-of-squares approaches. In this paper, we present the proposed noise characterization method and compare it to previous techniques using Monte Carlo simulations as well as phantom acquisitions.
Autors: Iñaki Rabanillo;Santiago Aja-Fernández;Carlos Alberola-López;Diego Hernando;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Feb 2018, volume: 37, issue:2, pages: 480 - 490
Publisher: IEEE
 
» Examining the Impact of a Crude Oil Spill on the Permittivity Profile and Normalized Radar Cross Section of Young Sea Ice
Abstract:
An oil-in-sea ice mesocosm experiment was conducted at the University of Manitoba Sea-Ice Environmental Research Facility from January to March 2016 in which geophysical and electromagnetic parameters of the ice were measured, and general observations about the oil-contaminated ice were made. From the experimental measurements, the presence of crude oil appears to affect the temperature and bulk salinity profiles as well as the normalized radar cross section (NRCS) of the contaminated young sea ice. The measured temperature and bulk salinity profiles of the ice, as well as the crude oil distribution within the ice, were used to model the permittivity profile of the oil-contaminated ice by adapting two mixture models commonly used to describe sea ice to account for the presence of oil. Permittivity modeling results were used to simulate the NRCS of the oil-contaminated sea ice in an effort to determine the accuracy of the models. In addition, the application of X-ray microtomography in modeling the dielectric profile of oil-contaminated sea ice was examined. The sensitivity of the permittivity models for oil-contaminated sea ice to changes in temperature, frequency, and oil volume fraction was also examined.
Autors: Thomas D. Neusitzer;Nariman Firoozy;Tyler M. Tiede;Durell S. Desmond;Marcos J. L. Lemes;Gary A. Stern;Søren Rysgaard;Puyan Mojabi;David G. Barber;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 921 - 936
Publisher: IEEE
 
» Exclusion of Linear Acceleration Signal in the MEMS Thermal Gyroscope
Abstract:
This letter identifies the source of linear acceleration signal in the microelectromechanical systems (MEMS) thermal gyroscope and provides a real-time solution to exclude it. The main culprit of the undesired acceleration signal is found to be lack of rotational symmetry due to Manhattan sensor topology. A higher level of symmetry is obtained by constructing a hybrid gyroscope using two individual devices operating in tandem but 180° out-of-phase. A precision rotary stage is used to test the duo. The experiments confirmed that higher symmetry is promising in excluding the acceleration signal. Compared with a single device, the hybrid gyroscope demonstrated 16-fold reduction in the acceleration signal and 5-fold improved acceleration to rotation sensitivities. [2017-0171]
Autors: Jamal Bahari;Carlo Menon;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Feb 2018, volume: 27, issue:1, pages: 19 - 21
Publisher: IEEE
 

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