Electrical and Electronics Engineering publications abstract of: 02-2018 sorted by title, page: 12

» Impact of CSI Uncertainty on MCIK-OFDM: Tight Closed-Form Symbol Error Probability Analysis
Abstract:
This paper proposes a novel framework to analyze the symbol error probability (SEP) for multicarrier index keying orthogonal frequency-division multiplexing (MCIK-OFDM) systems. Considering two different types of detections such as the maximum likelihood (ML) and low-complexity greedy detectors (GD), we derive tight closed-form expressions for the average SEPs of MCIK-OFDM in the presence of channel state information (CSI) uncertainty. We undertake an asymptotic performance analysis with respect to three CSI conditions, which ensures to provide a comprehensive insight into the achievable diversity and coding gains as well as the impact of various CSI uncertainties on the SEP performance. The SEP performance comparison between the ML and GD is obtained under different CSI uncertainties. This interestingly reveals that the GD can achieve nearly optimal error performance as the -ary modulation size is large or even outperforms the ML under certain CSI conditions. Finally, the theoretical and asymptotic analysis are verified via simulation results, obtaining the high accuracy of the derived SEP.
Autors: Thien Van Luong;Youngwook Ko;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1272 - 1279
Publisher: IEEE
 
» Impact of Doping Concentration on Electronic Properties of Transition Metal-Doped Monolayer Molybdenum Disulfide
Abstract:
Doping engineering has been an emerging topic in monolayer molybdenum disulfide (mMoS2). However, the dopants used for an n- or p-type device and the effect of doping level are of great interests toward next-generation electronic devices. In this paper, we theoretically reveal the work function tunability of mMoS2 doped by 3d transition metals. We found that the titanium dopant forms a deep-level trap in the midgap of mMoS2 but turning into n-type donor levels in high doping concentration due to the stronger covalent bond and the stable surface morphology, which renders it the widest work function tunability among 3d transition metals. Overall, the n-type behavior is expected by doping with chromium, copper, scandium, and titanium, whereas nickel and zinc dopants lead to the p-type property. The findings feature the selection of dopants for the revolutionary device and highlight the impact of doping levels from the atomistic viewpoint.
Autors: Yi-Chia Tsai;Yiming Li;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 733 - 738
Publisher: IEEE
 
» Impact of I/Q Amplitude Imbalance on Coherent $Phi $ -OTDR
Abstract:
In this paper, the quadrature amplitude imbalance which may consist in I/Q demodulated phase-sensitive optical time-domain reflectometry (-OTDR) is analyzed, which may happen in both ac and dc components of received signals. Based on the analysis of imperfect coherent detection module, the impacts of each imbalance factor on the demodulated sensing results of -OTDR are discussed qualitatively and quantitatively. The amplitude mismatch of ac and dc components may incur the distortion of demodulated signals, while the effect caused by residual dc parts is significantly severer than the impacts of ac imbalance. When both factors are present simultaneously, the ac amplitude imbalance can further degrade the demodulated signals distorted by residual dc components. Furthermore, this paper proposes a corresponding method to characterize and compensate the amplitude imbalance dynamically, using the real-time data of -OTDR traces. This method is also feasible for other fiber-optic sensing/communication systems with coherent detection.
Autors: Yun Fu;Naitian Xue;Zinan Wang;Bin Zhang;Ji Xiong;Yunjiang Rao;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2018, volume: 36, issue:4, pages: 1069 - 1075
Publisher: IEEE
 
» Impact of Imperfect CSI on ASER of Hexagonal and Rectangular QAM for AF Relaying Network
Abstract:
In this letter, we derive the closed-form expression of outage probability for a dual-hop variable-gain amplify-and-forward relay network. The maximal ratio combining receiver over independent and non-identically distributed frequency flat Nakagami-m fading channels with integer-valued fading parameter and imperfect channel state information (CSI) is considered. Asymptotic analysis on outage probability is also performed. Average symbol error rate (ASER) expressions are derived for general-order hexagonal and rectangular QAM schemes using the cumulative distribution function-based approach. The impact of the fading parameter and imperfect CSI are highlighted on the system performance. Comparative analysis of ASER performance for different QAM constellations is also illustrated. Monte Carlo simulations are performed to validate the derived analytical results for both perfect and imperfect CSI.
Autors: Praveen Kumar Singya;Nagendra Kumar;Vimal Bhatia;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 428 - 431
Publisher: IEEE
 
» Impact of Power-Electronic Sources on Transmission Line Ground Fault Protection
Abstract:
Power-electronic sources, such as Type 3 wind turbine generators and static synchronous compensators (STATCOM), interface to the grid through, partial- or full-scale, and power converters that have inherently fast switching capability to control their output current during short circuits. The short-circuit current is a function of the specific converter control algorithm and differs significantly from the conventional rotating machine sources without converter interfaces. Therefore, if a transmission-line protection scheme is designed for conventional sources, (not taking into account these differences in short-circuit current characteristics), reliability can be at risk. Using real-life short-circuit currents on lines supplied by sources having a power converter interface, this paper illustrates the reliability risk to conventional line protection schemes, in particular, to those which use negative-sequence quantities for the detection of unbalanced faults. This paper discusses the protection schemes, adopted by BC Hydro–a large Canadian Electric Utility, for transmission lines interconnecting Type 3 wind turbine and STATCOM sources. Their application for ground faults is independent of the converter control algorithm as long as the source is interconnected to the grid via a transformer which is a source of zero-sequence current.
Autors: Mukesh Nagpal;Charles Henville;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 62 - 70
Publisher: IEEE
 
» Impact of the Fiber Coating on the Temperature Response of Distributed Optical Fiber Sensors at Cryogenic Ranges
Abstract:
The thermomechanical behavior of a standard single-mode fiber with different coating materials is theoretically analyzed under different temperature conditions. Results show that the thermal expansion/shrinkage of the fiber coating introduces an extra strain on the optical fiber and can modify its thermal response. Distributed fiber sensors based on coherent Rayleigh and Brillouin scatterings are employed to characterize the impact of different coatings on the temperature sensitivity. The standard coating with dual-layer demonstrates a little influence on the thermal response at room temperature due to the softness of primary coating, but it increases the temperature sensitivity by some 50% at ∼220 K as the primary coating becomes stiffer at low temperature. Optical fibers with aluminum and Ormocer coatings are also experimentally tested. All the measured results agree well with the theoretical analysis.
Autors: Xin Lu;Marcelo A. Soto;Luc Thévenaz;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2018, volume: 36, issue:4, pages: 961 - 967
Publisher: IEEE
 
» Impact of the Gate and Insulator Geometrical Model on the Static Performance and Variability of Ultrascaled Silicon Nanowire FETs
Abstract:
We investigate the effect of the geometrical model adopted for the gate electrode and for the insulator enveloping the access regions on the full-quantum simulation of ultrascaled nanowire FETs (NW-FETs). We compare the results obtained in the “minimal” geometry commonly used in simulations with those obtained in a more realistic one, able to fully account for the gate fringing effects. We evaluate the impact of the model geometry on the static performance of NW-FETs and discuss the interplay with the surface roughness and the random distribution of dopants. We find that the ratio evaluated in the minimal geometry can be remarkably underestimated in short devices, notably in the case of small length-to-width ratio. The roughness-induced current degradation and the sensitivity to the surface roughness variability can also suffer from nonnegligible underestimations when evaluated in this geometry. Finally, we point out that an inaccurate description of the device electrostatics is expected to result in an overestimation of the sensitivity to the doping-induced variability.
Autors: Demetrio Logoteta;Nicolas Cavassilas;Alessandro Cresti;Marco G. Pala;Marc Bescond;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 424 - 430
Publisher: IEEE
 
» Impedance Measures During in vitro Cochlear Implantation Predict Array Positioning
Abstract:
Objective: Improper electrode placement during cochlear implant (CI) insertion can adversely affect speech perception outcomes. However, the intraoperative methods to determine positioning are limited. Because measures of electrode impedance can be made quickly, the goal of this study was to assess the relationship between CI impedance and proximity to adjacent structures. Methods: An Advanced Bionics CI array was inserted into a clear, plastic cochlea one electrode contact at a time in a saline bath (nine trials). At each insertion depth, response to biphasic current pulses was used to calculate access resistance (Ra), polarization resistance (Rp), and polarization capacitance (Cp). These measures were correlated to actual proximity as assessed by microscopy using linear regression models. Results: Impedance increased with insertion depth and proximity to the inner wall. Specifically, Ra increased, Cp decreased, and Rp slightly increased. Incorporating all impedance measures afforded a prediction model (r = 0.88) while optimizing for sub-mm positioning afforded a model with 78.3% specificity. Conclusion: Impedance in vitro greatly changes with electrode insertion depth and proximity to adjacent structures in a predicable manner. Significance : Assessing proximity of the CI to adjacent structures is a significant first step in qualifying the electrode-neural interface. This information should aid in CI fitting, which should help maximize hearing and speech outcomes with a CI. Additionally, knowledge of the relationship between impedance and positioning could have utility in other tissue implants in the brain, retina, or spinal cord.
Autors: Christopher Kenneth Giardina;Elliot Samuel Krause;Kanthaiah Koka;Douglas Carl Fitzpatrick;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Feb 2018, volume: 65, issue:2, pages: 327 - 335
Publisher: IEEE
 
» Impedance-Based Fault Location Algorithm for Ground Faults in Series-Capacitor-Compensated Transmission Lines
Abstract:
Locating a fault in a series-capacitor-compensated transmission line (SCCTL) is a challenging task due to the action of a metal-oxide varistor a nonlinear element present as a part of the protection system of the series capacitor. In this paper, an accurate fault-location algorithm that uses synchronized measurements from both ends of the SCCTL is presented which provides fault-location results without using the model of MOV or natural fault loop for single-phase-to-ground, and double-phase-to-ground faults. Another salient feature of the proposed technique is that the subroutines for locating faults in different sections transmission line yield almost identical fault-location results regardless of which section the transmission line is faulted. The proposed technique could also be extended to the double-circuit transmission lines. First, the proposed technique is introduced and its features are elaborated through detailed mathematical analysis. Thereafter, a 500- system with an SCCTL is designed in PSCAD, while the fault-location algorithm is modeled in MATLAB. The proposed algorithm is tested through simulations covering various fault scenarios in an SCCTL. For performance evaluation, the comparative analysis of the proposed technique with a well-known existing technique is performed in this paper.
Autors: Tirath Pal S. Bains;Tarlochan S. Sidhu;Zhihan Xu;Ilia Voloh;Mohammad R. Dadash Zadeh;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 189 - 199
Publisher: IEEE
 
» Imperfect Information Dynamic Stackelberg Game Based Resource Allocation Using Hidden Markov for Cloud Computing
Abstract:
Existing static grid resource scheduling algorithms, which are limited to minimizing the makespan, cannot meet the needs of resource scheduling required by cloud computing. Current cloud infrastructure solutions provide operational support at the level of resource infrastructure only. When hardware resources form the virtual resource pool, virtual machines are deployed for use transparently. Considering the competing characteristics of multi-tenant environments in cloud computing, this paper proposes a cloud resource allocation model based on an imperfect information Stackelberg game (CSAM-IISG) using a hidden Markov model (HMM) in a cloud computing environment. CSAM-IISG was shown to increase the profit of both the resource supplier and the applicant. Firstly, we used the HMM to predict the service provider's current bid using the historical resources based on demand. Through predicting the bid dynamically, an imperfect information Stackelberg game (IISG) was established. The IISG motivates service providers to choose the optimal bidding strategy according to the overall utility, achieving maximum profits. Based on the unit prices of different types of resources, a resource allocation model is proposed to guarantee optimal gains for the infrastructure supplier. The proposed resource allocation model can support synchronous allocation for both multi-service providers and various resources. The simulation results demonstrated that the predicted price was close to the actual transaction price, which was lower than the actual value in the game model. The proposed model was shown to increase the profits of service providers and infrastructure suppliers simultaneously.
Autors: Wei Wei;Xunli Fan;Houbing Song;Xiumei Fan;Jiachen Yang;
Appeared in: IEEE Transactions on Services Computing
Publication date: Feb 2018, volume: 11, issue:1, pages: 78 - 89
Publisher: IEEE
 
» Implementation of ITER Fast Plant Interlock System Using FPGAs With CompactRIO
Abstract:
Interlocks are the instrumented functions of ITER that protect the machine against failures of the plant system components or incorrect machine operation. Regarding instrumentation and control, the interlock control system (ICS) ensures that no failure of the conventional ITER controls can lead to a serious damage of the machine integrity or availability. The ICS is in charge of the supervision and control of all the ITER components involved in the instrumented protection of the tokamak and its auxiliary systems. It is constituted by the central interlock system (CIS), different plant interlock systems (PISs), and its networks. The ICS does not include the sensors and actuators of the plant systems, but it is in charge of their control. The ITER interlock system shall be designed, built, and operated according to the highest quality standards. The international standard IEC-61508 has been chosen as the reference. In both CIS and PIS cases, two main architectures are used: 1) a slow architecture, for those functions with response time requirements slower than 100 ms (300 ms for central interlock functions), based on programmable logic controller technologies and 2) a fast architecture, based on field programmable gate array (FPGA) technologies, for the functions with faster requirement times. The proposed design for fast PIS is based on the use of reconfigurable input/output (RIO) technology from National Instruments (NI CompactRIO platform). In order to provide a high integrity solution, failure modes, effects, and diagnostic analysis (FMEDA) has been conducted to analyze the component behavior. According to the output of the FMEDA, a set of diagnostics has been defined and additional redundancy was added to the architecture to improve the integrity figures. The defined configuration has been called the “double-decker solution,” with two chassis running in parallel, communicated between them using a synchronous high-speed seria- line, and using redundant modules to implement the input and output measurements/excitations and redundant analog and digital modules to implement the diagnostics of these input/output modules. The integrity figures for the “double-decker” solution are obtained from the classification of the failure rates, obtaining for different configurations a safe failure fraction of 85% and a probability of dangerous failure per hour of less than 1E−07. The FPGA design includes all the hardware to support the data acquisition from the input modules, the implementation of the diagnostic functionalities for analog and digital modules, the voting schema, and the activation/deactivation of digital outputs. The platform includes an external test platform, also based on NI CompactRIO technology, to perform the validation of the system and to register the performance of different interlock functions implemented. The response time obtained for the transistor–transistor logic (TTL) input to TTL output interlock function ranges from 5 to ; for the analog input to TTL output, the response time is in the range of 41–, and for interlock functions using 24-V digital input to 24-V digital output, the time can rise up to .
Autors: E. Barrera;M. Ruiz;A. Bustos;M. Afif;B. Radle;J. L. Fernández-Hernando;I. Prieto;R. Pedica;J. M. Barcala;J. C. Oller;R. Castro;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Feb 2018, volume: 65, issue:2, pages: 796 - 804
Publisher: IEEE
 
» Improved AlGaN/GaN Metal–Oxide– Semiconductor High-Electron Mobility Transistors With TiO2 Gate Dielectric Annealed in Nitrogen
Abstract:
An AlGaN/GaN metal–oxide–semiconductor high-electron mobility transistor (MOS-HEMT) that uses a high-k TiO2 gate insulator is demonstrated. TiO2 films are annealed at 300 °C and 600 °C in N2 or O2 following the deposition of an oxide layer. Experimental results reveal that the 300 °C N2-annealed TiO2/GaN MOS capacitor has the smallest interface traps of any of the studied devices. The 300 °C N2-annealed oxide interlayers between the GaN and the gate metal reduce the gate leakage current and improve the dc, high-frequency, and noise characteristics. The gate leakage current of the 300 °C N2-annealed MOS-HEMT is more than 3 orders of magnitude less than that of the baseline HEMT. This brief is the first to fabricate a GaN-based MOS-HEMT using an N2-annealed TiO2 gate insulator.
Autors: Yu-Shyan Lin;Chi-Che Lu;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 783 - 787
Publisher: IEEE
 
» Improved Contrast-Enhanced Ultrasound Imaging With Multiplane-Wave Imaging
Abstract:
Contrast-enhanced ultrasound (CEUS) imaging has great potential for use in new ultrasound clinical applications such as myocardial perfusion imaging and abdominal lesion characterization. In CEUS imaging, contrast agents (i.e., microbubbles) are used to improve contrast between blood and tissue because of their high nonlinearity under low ultrasound pressure. However, the quality of CEUS imaging sometimes suffers from a low signal-to-noise ratio (SNR) in deeper imaging regions when a low mechanical index (MI) is used to avoid microbubble disruption, especially for imaging at off-resonance transmit frequencies. In this paper, we propose a new strategy of combining CEUS sequences with the recently proposed multiplane-wave (MW) compounding method to improve the SNR of CEUS in deeper imaging regions without increasing MI or sacrificing frame rate. The MW-CEUS method emits multiple Hadamard-coded CEUS pulses in each transmission event (i.e., pulse-echo event). The received echo signals first undergo fundamental bandpass filtering (i.e., the filter is centered on the transmit frequency) to eliminate the microbubble’s second-harmonic signals because they cannot be encoded by pulse inversion. The filtered signals are then Hadamard decoded and realigned in fast time to recover the signals as they would have been obtained using classic CEUS pulses, followed by designed recombination to cancel the linear tissue responses. The MW-CEUS method significantly improved contrast-to-tissue ratio and SNR of CEUS imaging by transmitting longer coded pulses. The image resolution was also preserved. The microbubble disruption ratio and motion artifacts in MW-CEUS were similar to those of classic CEUS imaging. In addition, the MW-CEUS sequence can be adapted to other transmission coding formats. These properties of MW-CEUS can potentially facilitate CEUS imaging for many clinical applications, especially assessing deep abdominal organs or the heart.
Autors: Ping Gong;Pengfei Song;Shigao Chen;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Feb 2018, volume: 65, issue:2, pages: 178 - 187
Publisher: IEEE
 
» Improved Estimation for Well-Logging Problems Based on Fusion of Four Types of Kalman Filters
Abstract:
The concept of information fusion has gained a widespread interest in many fields due to its complementary properties. It makes systems more robust against uncertainty. This paper presents a new approach for the well-logging estimation problem by using a fusion methodology. The natural gamma-ray tool (NGT) is considered as an important instrument in the well logging. The NGT detects changes in natural radioactivity emerging from the variations in concentrations of micronutrients as uranium (U), thorium (Th), and potassium (K). The main goal of this paper is to have precise estimation of the concentrations of , , and . Four types of Kalman filters are designed to estimate the elements using the NGT sensor. Then, a fusion of the Kalman filters is utilized into an integrated framework by an ordered weighted averaging (OWA) operator to enhance the quality of the estimations. A real covariance of the output error based on the innovation matrix is utilized to design weighting factors for the OWA operator. The simulation studies indicate not only a reliable performance of the proposed method compared with the individual Kalman filters but also a better response in contrast with previous fusion methodologies.
Autors: Sina Soltani;Mojtaba Kordestani;Paknoosh Karim Aghaee;Mehrdad Saif;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 647 - 654
Publisher: IEEE
 
» Improved Frequency Regulation in an Islanded Mixed Source Microgrid Through Coordinated Operation of DERs and Smart Loads
Abstract:
The advent of microgrids paved the way for energy decentralization and self-sufficiency among consumers. Reciprocating engine-driven synchronous generators (also known as gensets) are one of the most commonly found distributed energy resources (DERs) installed in a microgrid. A key concern in microgrid operation is the frequency regulation, especially when it is islanded from the main grid. In recent years, the inverter-based DERs have witnessed huge growth. When fast-responding inverter-based DERs are working in parallel with the slow-acting gensets within the islanded mixed source microgrid, many challenges exist in coordinating their operation. In particular, an inverter-based DER is susceptible to collapse due to its large transient loading and this can bring down the entire system. This paper investigates load sharing and proposes new techniques for improved frequency regulation in an islanded mixed source microgrid. An improved coordination scheme between DERs is presented in this paper by accounting for their inertial and governor response characteristics. The unequal transient load sharing between gensets and inverter-based DERs is redistributed to prevent system collapse as well as achieve desired frequency regulation. For dealing with extreme scenarios, a smart load shedding scheme is integrated into the coordinated operation of DERs.
Autors: Abrez Mondal;Mahesh S. Illindala;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 112 - 120
Publisher: IEEE
 
» Improved NO and NO2 Concentration Estimation for a Diesel-Engine-Aftertreatment System
Abstract:
The high nitrogen oxide () emission is one of the main issues for diesel engines. To reduce the emissions with an after-treatment system, the information of NO and NO2 concentrations plays an important role. In this paper, we investigate the NO and NO2 concentration estimation for a diesel-engine-after-treatment system with sensor measurements. The main objective is to estimate the NO and NO2 concentrations after diesel particulate filter (DPF) such that the selective catalytic reduction system can be benefited from the estimated concentrations. Since the diesel oxidation catalyst (DOC) is connected in series with DPF, the estimation work for DOC is also necessary. An empirical engine-out NO2/ ratio model is adopted to predict the inputs of DOC. By considering the main chemical reactions inside DOC and DPF, the NO and NO2 concentration models are obtained. The nonlinear models are converted into linear-parameter-varying forms. Then, a gain-scheduling Luenburger observer is proposed for the DOC and DPF. A practical assumption in which the system modeling and sensor measurements are not perfectly precise is made. Therefore, the gain-scheduling Luenburger observer does not directly share the weighting factors of the original system. By defining the estimation error, an augmented compact system is obtained. Both the stability and the energy-to-peak performance are investigated for the compact system. Based on the derived conditions, the observer design approach is proposed. Experimental studies and comparisons are given to validate the results. Compared with an existing work- the designed observer can improve the estimation performance significantly.
Autors: Hui Zhang;Junmin Wang;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Feb 2018, volume: 23, issue:1, pages: 190 - 199
Publisher: IEEE
 
» Improved Optimal Route Evaluation Method for Wireless Sensor Networks
Abstract:
It is well known that both a “minimal energy consuming path” and “balanced communication load among the nodes” are necessary criteria for route evaluation. To achieve acceptable performance, these two requirements must be well balanced. To provide this balance, we propose an improved optimal route evaluation method based on the principal component approach for wireless sensor networks. This method ensures a diversified evaluation and prompt dynamic load balance in different network monitoring environments. Further, the weighting factor of each evaluation indicator can be estimated using the principal component approach. This method can avoid the problem of requiring manual selection of weight factors based on experience, which lacks guidance based on scientific theories, is subjective, and may negatively affect evaluation precision. Comparison with other state-of-the-art algorithms confirms that the proposed evaluation function improves the performance of a network significantly.
Autors: Kui Liu;Chunfeng Wang;
Appeared in: IEEE Sensors Journal
Publication date: Feb 2018, volume: 18, issue:4, pages: 1747 - 1754
Publisher: IEEE
 
» Improved Prosthetic Control Based on Myoelectric Pattern Recognition via Wavelet-Based De-Noising
Abstract:
Real-time inference of human motor volition has great potential for the intuitive control of robotic devices. Toward this end, myoelectric pattern recognition (MPR) has shown promise in the control of prosthetic limbs. Interfering noise and susceptibility to motion artifacts have hindered the use of MPR outside controlled environments, and thus represent an obstacle for clinical use. Advanced signal processing techniques have been previously proposed to improve the robustness of MPR systems. However, the investigation of such techniques have been limited to offline implementations with long time windows, which makes real-time use unattainable. In this work, we present a novel algorithm using discrete and stationary wavelet transforms for MPR that can be executed in real-time. Our wavelet-based de-noising algorithm outperformed conventional band-pass filtering (up to 100 Hz) and improved real-time MPR in the presence of motion artifacts, as measured by the motion test. Improved signal-to-noise ratio was found not to be crucial in offline MPR, as machine learning algorithms can integrate high but consistent noise as part of the signal. However, varying interference is expected to occur in real life where signal processing algorithms, as the one introduced in this paper, would potentially have a positive impact. Furthermore implementation of these algorithms in a prosthetic embedded system is required to validate their feasibility and usability during activities of the daily living.
Autors: Julian Maier;Adam Naber;Max Ortiz-Catalan;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Feb 2018, volume: 26, issue:2, pages: 506 - 514
Publisher: IEEE
 
» Improved Responsivity Drop From 250 to 200 nm in Sputtered Gallium Oxide Photodetectors by Incorporating Trace Aluminum
Abstract:
A solar-blind photodetector (PD) based on the cosputtered aluminum–gallium oxide (AGO) material after thermal annealing at 900 °C has been demonstrated using a metal–semiconductor–metal structure. By incorporating optimum trace aluminum (Al), the AGO PD shows the peak responsivity (at 230 nm) of 1.38 A/W under a bias voltage of 5 V, which is 53.61 times greater than that of the PD from the gallium oxide (GO) film without incorporating any Al content. The photocurrent, dark current, and detectivity (at 5 V and 230 nm) of AGO PD are also improved to be 46.4, 0.83, and 96.5 times, respectively, greater than those of GO one. Unlike conventional GO samples revealing obvious drop in spectral response from 250 to 200 nm, the AGO PD with an Al/(Al + Ga) ratio of 1.8% exhibits a nearly flat responsivity curve in the deep ultraviolet region. This improvement is significant compared with previous reports for the GO and AGO PDs by other growth methods.
Autors: Shuo-Huang Yuan;Chao-Chun Wang;Shiau-Yuan Huang;Dong-Sing Wuu;
Appeared in: IEEE Electron Device Letters
Publication date: Feb 2018, volume: 39, issue:2, pages: 220 - 223
Publisher: IEEE
 
» Improved Subthreshold Swing and Short Channel Effect in FDSOI n-Channel Negative Capacitance Field Effect Transistors
Abstract:
Negative capacitance (NC) FETs with channel lengths from 30 nm to , gated with ferroelectric hafnium zirconium oxide are fabricated on fully depleted silicon-on-insulator (FDSOI) substrates. Enhanced capacitance due to NC, hysteresis-free operation, and improved subthreshold slope are observed. The NC effect leads to enhancement of drain current for small voltage operation. In addition, improved short channel performance is demonstrated owing to the reverse drain induced barrier lowering characteristics of the NC operation.
Autors: Daewoong Kwon;Korok Chatterjee;Ava J. Tan;Ajay K. Yadav;Hong Zhou;Angada B. Sachid;Roberto Dos Reis;Chenming Hu;Sayeef Salahuddin;
Appeared in: IEEE Electron Device Letters
Publication date: Feb 2018, volume: 39, issue:2, pages: 300 - 303
Publisher: IEEE
 
» Improved Super-Resolution Ultrasound Microvessel Imaging With Spatiotemporal Nonlocal Means Filtering and Bipartite Graph-Based Microbubble Tracking
Abstract:
Super-resolution ultrasound microvessel imaging with contrast microbubbles has recently been proposed by multiple studies, demonstrating outstanding resolution with high potential for clinical applications. This paper aims at addressing the potential noise issue in in vivo human super-resolution imaging with ultrafast plane-wave imaging. The rich spatiotemporal information provided by ultrafast imaging presents features that allow microbubble signals to be separated from background noise. In addition, the high-frame-rate recording of microbubble data enables the implementation of robust tracking algorithms commonly used in particle tracking velocimetry. In this paper, we applied the nonlocal means (NLM) denoising filter on the spatiotemporal domain of the microbubble data to preserve the microbubble tracks caused by microbubble movement and suppress random background noise. We then implemented a bipartite graph-based pairing method with the use of persistence control to further improve the microbubble signal quality and microbubble tracking fidelity. In an in vivo rabbit kidney perfusion study, the NLM filter showed effective noise rejection and substantially improved microbubble localization. The bipartite graph pairing and persistence control demonstrated further noise reduction, improved microvessel delineation, and a more consistent microvessel blood flow speed measurement. With the proposed methods and freehand scanning on a free-breathing rabbit, a single microvessel cross-sectional profile with full-width at half-maximum of could be imaged at approximately 2-cm depth (ultrasound transmit center frequency = 8 MHz, theoretical spatial resolution ). Cortical microvessels that are apart can also be clearly separated. These results suggest that the proposed methods have good potential in facilitating robust in vivo clinical super-resolution microvessel imaging.
Autors: Pengfei Song;Joshua D. Trzasko;Armando Manduca;Runqing Huang;Ramanathan Kadirvel;David F. Kallmes;Shigao Chen;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Feb 2018, volume: 65, issue:2, pages: 149 - 167
Publisher: IEEE
 
» Improved Synapse Device With MLC and Conductance Linearity Using Quantized Conduction for Neuromorphic Systems
Abstract:
In this letter, we demonstrate the conductive-bridging RAM (CBRAM) with excellent multi-level cell (MLC) and linear conductance characteristics for an artificial synaptic device of neuromorphic systems. Our findings show that inherent characteristics of CBRAM can achieve the linear conductance and MLC characteristics as a product of an integer unit of the conductance. However, uncontrolled metal-ion injection into the switching layer results in a significant degradation of device uniformity, leading to degradation in the classification accuracy. Thus, we introduce a multi-layer CBRAM configuration (Cu/HfO2/Ta/Cu2S/W) to control the ionic motion in electrolytes. As a result of device engineering, highly improved classification accuracy is achieved using CIFAR-10 data set.
Autors: Seokjae Lim;Changhyuck Sung;Hyungjun Kim;Taesu Kim;Jeonghwan Song;Jae-Joon Kim;Hyunsang Hwang;
Appeared in: IEEE Electron Device Letters
Publication date: Feb 2018, volume: 39, issue:2, pages: 312 - 315
Publisher: IEEE
 
» Improved Visualization of Gastrointestinal Slow Wave Propagation Using a Novel Wavefront-Orientation Interpolation Technique
Abstract:
Objective: High-resolution mapping of gastrointestinal (GI) slow waves is a valuable technique for research and clinical applications. Interpretation of high-resolution GI mapping data relies on animations of slow wave propagation, but current methods remain as rudimentary, pixelated electrode activation animations. This study aimed to develop improved methods of visualizing high-resolution slow wave recordings that increases ease of interpretation. Methods: The novel method of “wavefront-orientation” interpolation was created to account for the planar movement of the slow wave wavefront, negate any need for distance calculations, remain robust in atypical wavefronts (i.e., dysrhythmias), and produce an appropriate interpolation boundary. The wavefront-orientation method determines the orthogonal wavefront direction and calculates interpolated values as the mean slow wave activation-time (AT) of the pair of linearly adjacent electrodes along that direction. Stairstep upsampling increased smoothness and clarity. Results: Animation accuracy of 17 human high-resolution slow wave recordings (64–256 electrodes) was verified by visual comparison to the prior method showing a clear improvement in wave smoothness that enabled more accurate interpretation of propagation, as confirmed by an assessment of clinical applicability performed by eight GI clinicians. Quantitatively, the new method produced accurate interpolation values compared to experimental data (mean difference 0.02 ± 0.05 s) and was accurate when applied solely to dysrhythmic data (0.02 ± 0.06 s), both within the error in manual AT marking (mean 0.2 s). Mean interpolation processing time was 6.0 s per wave. Conclusion and Significance: These novel methods provide a validated visualization platform that will improve analysis of high-resolution GI mapp- ng in research and clinical translation.
Autors: Terence P. Mayne;Niranchan Paskaranandavadivel;Jonathan C. Erickson;Gregory O'Grady;Leo K. Cheng;Timothy R. Angeli;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Feb 2018, volume: 65, issue:2, pages: 319 - 326
Publisher: IEEE
 
» Improvement of Energy Transfer in a Cavity-Type 915-MHz Microwave Plasma Source
Abstract:
An improvement in the energy transfer in a cavity-type microwave plasma source (MPS) operated at 915 MHz by a better design of the device, capable of ensuring a high microwave power coupling from the supply line to the sustained plasma was a goal of this paper. Our approach was twofold. First, numerical simulations of an electromagnetic field distribution inside a typical cavity-type MPS were carried out. The standard model of homogeneous plasma generated by the MPS and the two-port method was combined. This enabled estimating the concentration and collisions frequency of electrons in the plasma. Based on these data, a more energy efficient MPS could be designed. Second, to verify the numerical prediction, a modified version of the MPS was built and the improvement in the MPS energy efficiency was proved experimentally.
Autors: Robert Miotk;Mariusz Jasiński;Jerzy Mizeraczyk;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Feb 2018, volume: 66, issue:2, pages: 711 - 716
Publisher: IEEE
 
» Improvement of Power Quality by Using Advanced Reactive Power Compensation
Abstract:
In the same feeder, it will decline the power quality of power supply when the quality is poor at load side, which can cause other equipment malfunction and even damage devices. Therefore, a reactive power compensation method is suggested to improve the power quality of the electric arc furnace in a distribution power system. Both the static var compensator (SVC) and an active filter can modify power factor and balance three phase currents simultaneously. The active filter can solve the problem of instantaneous state of an SVC. Then, an SVC can reduce power quantity of the active filter. Finally, field measurement data in a metal factory were analyzed. Simulation results confirmed the feasibility of correcting the power factor and balancing load currents simultaneously using the proposed method.
Autors: Yu-Wei Liu;Shiuan-Hau Rau;Chi-Jui Wu;Wei-Jen Lee;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 18 - 24
Publisher: IEEE
 
» Improvement of Reflection Detection Success Rate of GNSS RO Measurements Using Artificial Neural Network
Abstract:
Global Navigation Satellite System (GNSS) radio occultation (RO) has been widely used in the prediction of weather, climate, and space weather, particularly in the area of tropospheric analyses. However, one of the issues with GNSS RO measurements is that they are interfered with by the signals reflected from the earth’s surface. Many RO events are subject to such interfered GNSS measurements, which are considerably difficult to extract from the GNSS RO measurements. To precisely identify interfered RO events, an improved machine learning approach—a gradient descent artificial neural network (ANN)-aided radio-holography method—is proposed in this paper. Since this method is more complex than most other machine learning methods, for improving its efficiency through the reduction in computational time for near-real-time applications, a scale factor and a regularization factor are also adjusted in the ANN approach. This approach was validated using Constellation Observing System for Meteorology, Ionosphere, and Climate/FC-3 atmPhs (level 1b) data during the period of day of year 172–202, 2015, and its detection results were compared with the flag data set provided by Radio Occultation Meteorology Satellite Application Facilities for the performance assessment and validation of the new approach. The results were also compared with those of the support vector machine method for improvement assessment. The comparison results showed that the proposed method can considerably improve both the success rate of GNSS RO reflection detection and the computational efficiency.
Autors: Andong Hu;Suqin Wu;Xiaoming Wang;Yan Wang;Robert Norman;Changyong He;Han Cai;Kefei Zhang;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 760 - 769
Publisher: IEEE
 
» Improvement of Threshold Voltage Reliability of 4H-SiC MOSFETs With Lanthanum Silicate by High Temperature Forming Gas Anneal
Abstract:
We report the effect of a high-temperature forming gas anneal (FGA) on the electrical characteristics and threshold voltage (VT) instability of high-mobility Si-face (0001) 4H-SiC metal oxide semiconductor field effect transistors (MOSFETs) with lanthanum silicate (LaSiOx). The MOSFET with LaSiOx after 800 °C FGA in 5% H2 and 95% N2 mixture shows significantly reduced VT shift under 3-MV/cm positive bias stressing from 2.78 to 1.65 V, while maintaining high field-effect mobility of 122.7 cm2/Vs and sufficiently positive VT of 2.76 V.
Autors: Xiangyu Yang;Bongmook Lee;Veena Misra;
Appeared in: IEEE Electron Device Letters
Publication date: Feb 2018, volume: 39, issue:2, pages: 244 - 247
Publisher: IEEE
 
» Improving Grid Power Availability in Rural Telecom Exchanges
Abstract:
India has seen a huge surge in the telecom sector with total rural telecom subscribers doubling from 200.81 million to 404.16 million between 2010 and 2015. Therefore, telecom exchanges are built throughout the country to support this development. With severe electric power shortages in rural India, it poses a challenge to power these exchanges. It is observed that power supply in rural areas is not always available in three phase and can sometimes be available in two or single phase depending on fault in the three-phase system. Currently, used power plants in telecom exchanges are not designed to adapt to these variable input phase conditions. In this paper, a method is proposed to modify the currently used power plants such that they easily adapt to variable input phase conditions. This will lead to the utmost utilization of grid power and save valuable diesel fuel used in back-up diesel generators. The proposed method is designed and verified to have reasonable input power quality as per international standards. A quantitative estimation of diesel savings is also presented to estimate the percentage of diesel savings as a function of power outage.
Autors: Santanu Mishra;Abhishek Maji;Soumya Shubhra Nag;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 636 - 646
Publisher: IEEE
 
» Improving Land Surface Temperature and Emissivity Retrieval From the Chinese Gaofen-5 Satellite Using a Hybrid Algorithm
Abstract:
Land surface temperature (LST) is a key surface feature parameter. Temperature and emissivity separation (TES) and split-window (SW) algorithms are two typical LST estimation algorithms that have been applied to a variety of sensors to generate LST products. The TES algorithm can synchronously obtain LST and emissivity, but it requires high accuracy for atmospheric correction of the thermal infrared (TIR) data and does not perform well for surfaces with low spectral emissivity contrast. On the contrary, the SW algorithm can retrieve LST without detailed atmospheric data because the linear or nonlinear combination of brightness temperatures in the two adjacent TIR channels can reduce the atmospheric effect; however, this algorithm requires prior accurate pixel emissivity. Combining the two algorithms can improve the accuracy of LST estimation because the emissivity calculated from the TES algorithm can be used in the SW algorithm, and the LST from the SW algorithm can then be applied to the TES algorithm as an initial value to refine emissivity and LST. This paper investigates the aforementioned hybrid algorithm using Chinese Gaofen-5 satellite data, which will provide four-channel data for TIR at 40 m for synchronously retrieving LST and emissivity. The results showed that the hybrid algorithm was less sensitive to instrument noise and atmospheric data error, and can obtain LST and emissivity with an error less than 1 K and 0.015, respectively, which is better than those obtained with the single TES or SW algorithm. Finally, the hybrid algorithm was tested in simulated image and ground-measured data, and obtained accurate results.
Autors: Huazhong Ren;Xin Ye;Rongyuan Liu;Jiaji Dong;Qiming Qin;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 1080 - 1090
Publisher: IEEE
 
» Improving Multipath Video Transmission With Raptor Codes in Heterogeneous Wireless Networks
Abstract:
Supported by the latest technical innovations mobile users are able to simultaneously receive real-time streaming services with different radio access technologies (e.g. LTE and Wi-Fi). The stream control transmission protocol (SCTP) is a vitally important transport protocol to enable concurrent multipath transfer (CMT) in heterogeneous wireless networks with multihomed terminals. However enabling CMT of real-time video streaming to multihomed mobiles is challenged with key technical dilemmas: 1) high-quality real-time video transmission is constrained by stringent requirements in delay and throughput; 2) wireless networks are bandwidth-limited and error-prone; and 3) the congestion control and packet retransmission modules in the SCTP may incur frequent deadline violations and throughput fluctuations. Motivated by addressing these challenging problems this research proposes a Video and Raptor code aware CMT (CMT-VR) solution. First we develop a mathematical model to formulate the utility maximization problem of multipath real-time video delivery over parallel wireless networks. Second we present a transmission framework that includes online packet scheduling Raptor coding adaptation and retransmission control algorithms. CMT-VR is distinct from the existing SCTPs in leveraging the video frame priority and rateless Raptor coding. The performance verification is conducted by means of system evaluations over real wireless networks and extensive semiphysical emulations in the Exata platform. Evaluation results demonstrate that CMT-VR achieves appreciable improvements over the reference schemes in perceived video quality goodput and end-to-end delay.
Autors: Jiyan Wu;Bo Cheng;Ming Wang;
Appeared in: IEEE Transactions on Multimedia
Publication date: Feb 2018, volume: 20, issue:2, pages: 457 - 472
Publisher: IEEE
 
» Improving Small-Signal Stability of an MMC With CCSC by Control of the Internally Stored Energy
Abstract:
The dc-side dynamics of modular multilevel converters (MMCs) can be prone to poorly damped oscillations or stability problems when the second-harmonic components of the arm currents are mitigated by a circulating current suppression controller (CCSC). This paper demonstrates that the source of these oscillations is the uncontrolled interaction of the dc-side current and the internally stored energy of the MMC, as resulting from the CCSC. Stable operation and improved performance of the MMC control system can be ensured by introducing the closed-loop control of the energy and the dc-side current. The presented analysis relies on a detailed state-space model of the MMC, which is formulated to obtain constant variables in steady state. The resulting state-space equations can be linearized to achieve a linear time invariant model, allowing for eigenvalue analysis of the small-signal dynamics of the MMC. Participation factor analysis is utilized to identify the source of the poorly damped dc-side oscillations, and indicates the suitability of introducing control of the internal capacitor voltage or the corresponding stored energy. An MMC connected to a dc power source with an equivalent capacitance, and operated with dc voltage droop in the active power flow control, is used as an example for the presented analysis. The developed small-signal models and the improvement in small-signal dynamics achieved by introducing control of the internally stored energy are verified by time-domain simulations in comparison to an electro-magnetic transient (EMT) simulation model of an MMC with 400 submodules per arm.
Autors: Julian Freytes;Gilbert Bergna;Jon Are Suul;Salvatore D’Arco;François Gruson;Frédéric Colas;Hani Saad;Xavier Guillaud;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 429 - 439
Publisher: IEEE
 
» Improving the Diversity of Faculty in Electrical and Computer Engineering (iREDEFINE ECE)
Abstract:
As women faculty in electrical and computer engineering (ECE), we have been involved in several efforts targeted at increasing the participation of women in ECE departments. For example, at Rutgers University, we have organized presentations and workshops for first year students that highlighted the societal aspects of ECE, such as bioelectrical engineering applications. Such focus did bear fruit; between 2010 and 2016, the sophomore female enrollment in ECE at Rutgers rose from 11% to 19%. At the University of San Diego, we have conducted research on the demographics and outcomes of undergraduate students in ECE, facilitated workshops to help faculty teach in more inclusive ways, and are currently working on a National Science Foundation (NSF)-funded effort to revolutionize engineering education [1]. Also, as chairs, we have been considering ways to diversify our faculty carefully considering the overall hiring process including innovative approaches such as cluster hires [2], paying close attention to the language used when advertising faculty positions, the discussions during the review of the candidates, the candidate selection criteria, and the interview process [3]. However, the number of diverse graduate students is small to begin with, and in an era in which companies have realized the value of diversity, academia has to compete with companies such as Google and Microsoft for the best Ph.D. graduates. Without a diverse faculty, we cannot sustain a diverse student body.
Autors: Athina Petropulu;Susan Lord;
Appeared in: Proceedings of the IEEE
Publication date: Feb 2018, volume: 106, issue:2, pages: 214 - 218
Publisher: IEEE
 
» Improving the SSD Performance by Exploiting Request Characteristics and Internal Parallelism
Abstract:
With the explosive growth in the data volume, the I/O bottleneck has become an increasingly daunting challenge for big data analytics. It is urgent and important to introduce high-performance flash-based solid state drives (SSDs) into the storage systems. However, since the existing systems are primarily designed for conventional magnetic hard disk drives, directly incorporating SSDs in the existing systems cannot fully exploit SSDs’ performance advantages. In this paper, we propose a new I/O scheduler for SSDs, namely Amphibian, that exploits the high-level request characteristics and low-level parallelism of flash chips to improve the performance of SSD-based storage systems. Amphibian includes two performance enhancement schemes: 1) size-based request ordering, which prioritizes requests with small sizes in processing and 2) garbage collection (GC)-aware request dispatching that delays issuing requests to flash chips that are in the GC state. These two schemes employed in Amphibian significantly reduce the average waiting times of the requests from the host. Our extensive evaluation results derived from three types of SSDs show that, compared with the existing I/O schedulers, Amphibian greatly improves both throughput and average response times for SSD-based storage systems, thus improving the I/O performance of the systems.
Autors: Bo Mao;Suzhen Wu;Lide Duan;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Feb 2018, volume: 37, issue:2, pages: 472 - 484
Publisher: IEEE
 
» Improving TMPA 3B43 V7 Data Sets Using Land-Surface Characteristics and Ground Observations on the Qinghai–Tibet Plateau
Abstract:
The accurate knowledge of precipitation information over the Qinghai–Tibet Plateau, where the rain gauge networks are limited, is vital for various applications. While satellite-based precipitation estimates provide high spatial resolution (0.25°), large uncertainties and systematic anomalies still exist over this critical area. To derive more accurate monthly precipitation estimates, a spatial data-mining algorithm was used to remove the obvious anomalies compared with their neighbors from the original Tropical Rainfall Measuring Mission (TRMM) multisatellite precipitation analysis (TMPA) 3B43 V7 data at an annual scale, as the TMPA data are more accurate than other satellite-based precipitation estimates. To supplement the international exchange stations, additional ground observations were used to calibrate and improve the TMPA data with anomalies removed at an annual scale. Finally, a disaggregation strategy was adopted to derive monthly precipitation estimates based on the calibrated TMPA data. We concluded that: 1) the obvious anomalies compared with their neighbors could be removed from the original TMPA data sets and 2) the calibrated results were of a higher quality than the original TMPA data in each month from 2000 to 2013. The improved TMPA 3B43 V7 data sets over the Qinghai–Tibet plateau, named NITMPA3B43_QTP, are available at http://agri.zju.edu.cn/NITMPA3B43_QTP/.
Autors: Ziqiang Ma;Lianqing Zhou;Wu Yu;Yuanyuan Yang;Hongfeng Teng;Z. Shi;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Feb 2018, volume: 15, issue:2, pages: 178 - 182
Publisher: IEEE
 
» Improving Transparency and Efficiency in IT Security Management Resourcing
Abstract:
The authors propose a resource management process for information security management systems to more transparently plan and assign costs of controls. The process relies on and is compliant with international standards of the ISO/IEC 27000 family and can be implemented by all organizations regardless of type, size, or nature.
Autors: Knut Haufe;Srdan Dzombeta;Knud Brandis;Vladimir Stantchev;Ricardo Colomo-Palacios;
Appeared in: IT Professional
Publication date: Feb 2018, volume: 20, issue:1, pages: 53 - 62
Publisher: IEEE
 
» IMS2017 Student Design Competition Results
Abstract:
Presents information on the IMS2017 Student Design Competition.
Autors: Robert Caverly;
Appeared in: IEEE Microwave Magazine
Publication date: Feb 2018, volume: 19, issue:1, pages: 67 - 68
Publisher: IEEE
 
» IMU-Based Wrist Rotation Control of a Transradial Myoelectric Prosthesis
Abstract:
This paper describes a control method intended to facilitate improved control of a myoelectric prosthesis containing a wrist rotator. Rather than exclusively utilizing electromyogram (EMG) for the control of all myoelectric components (e.g., a hand and a wrist), the proposed controller utilizes inertial measurement (from six-axis inertial measurement unit (IMU)) to sense upper arm abduction/adduction, and uses this input to command a wrist rotation velocity. As such, the controller essentially substitutes shoulder abduction/adduction in place of agonist/antagonist EMG to control wrist angular velocity, which preserves EMG for control of the hand (or other arm components). As a preliminary assessment of efficacy, the control method was implemented on a transradial prosthesis prototype with a powered wrist rotator and hand, and experimentally assessed on five able-bodied subjects who wore the prototype using an able-bodied adaptor and one transradial amputee subject while performing assessments representative of activities of daily living. The assessments compared the (timed) performance of the combined EMG/ IMU-based control method with a (conventional) sequential EMG control approach. Results of the assessment indicate that the able-bodied subjects were able to perform the tasks 33% faster on average with the EMG/IMU-based method, relative to a conventional sequential EMG method. The same assessment was subsequently conducted using a single transradial amputee subject, which resulted in similar performance trends, although with a somewhat lessened effect size—specifically, the amputee subject was on average 22% faster in performing tasks with the IMU-based controller.
Autors: Daniel A. Bennett;Michael Goldfarb;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Feb 2018, volume: 26, issue:2, pages: 419 - 427
Publisher: IEEE
 
» In Vivo Characterization of a Wireless Telemetry Module for a Capsule Endoscopy System Utilizing a Conformal Antenna
Abstract:
This paper describes the design, fabrication, packaging, and performance characterization of a conformal helix antenna created on the outside of a capsule endoscope designed to operate at a carrier frequency of 433 MHz within human tissue. Wireless data transfer was established between the integrated capsule system and an external receiver. The telemetry system was tested within a tissue phantom and in vivo porcine models. Two different types of transmission modes were tested. The first mode, replicating normal operating conditions, used data packets at a steady power level of 0 dBm, while the capsule was being withdrawn at a steady rate from the small intestine. The second mode, replicating the worst-case clinical scenario of capsule retention within the small bowel, sent data with stepwise increasing power levels of –10, 0, 6, and 10 dBm, with the capsule fixed in position. The temperature of the tissue surrounding the external antenna was monitored at all times using thermistors embedded within the capsule shell to observe potential safety issues. The recorded data showed, for both modes of operation, a low error transmission of 10−3 packet error rate and 10−5 bit error rate and no temperature increase of the tissue according to IEEE standards.
Autors: Julia Faerber;Gerard Cummins;Sumanth Kumar Pavuluri;Paul Record;Adrian R. Ayastuy Rodriguez;Holly S. Lay;Rachael McPhillips;Benjamin F. Cox;Ciaran Connor;Rachael Gregson;Richard Eddie Clutton;Sadeque Reza Khan;Sandy Cochran;Marc P. Y. Desmulliez;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Feb 2018, volume: 12, issue:1, pages: 95 - 105
Publisher: IEEE
 
» In-Line Tunable Nematic Liquid Crystal Fiber Optic Device
Abstract:
This paper has been focused on design, fabrication, and characterization of a new in-line tunable nematic liquid crystal fiber optic device. The application of a biconical optical fiber taper as a core surrounded by liquid crystals’ molecules as cladding gives the possibility to voltage control of spectral characteristics including system losses and its polarization in an optical visible wavelength range from 500 to 700 nm. The device is based on a standard single mode telecommunication fiber and a special, nematic liquid crystalline mixture of a 1550C1 type. The temperature and time course of liquid crystal mixture investigation of the proposed element are also included in the paper.
Autors: Joanna E. Moś;Mariusz Florek;Katarzyna Garbat;Karol A. Stasiewicz;Noureddine Bennis;Leszek R. Jaroszewicz;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2018, volume: 36, issue:4, pages: 891 - 897
Publisher: IEEE
 
» Inadequate Software Testing Can Be Disastrous [Essay]
Abstract:
Writing code is just one part of the software development lifecycle. The testing phase occurs at the end of the process, but it is equally important. Testing uncovers errors and verifies software; it provides an opportunity to fix problems and make improvements. Unfortunately, testing is sometimes overlooked, and software errors occur. Activision learned this difficult lesson when it failed to fully test its video game. Recent history has shown that even more disastrous results can occur from inadequate software testing.
Autors: Edwin Torres;
Appeared in: IEEE Potentials
Publication date: Feb 2018, volume: 37, issue:1, pages: 9 - 47
Publisher: IEEE
 
» Incentive Mechanism and Rating System Design for Crowdsourcing Systems: Analysis, Tradeoffs and Inference
Abstract:
Macrotasking crowdsourcing systems like Elance and Fiverr serve as efficient platforms for requesters to outsource challenging and innovative tasks that require special skills to workers. It is widely practiced in such systems that requesters reward workers based on requesters’ assessment on solution quality. The challenge is that requesters’ assessment may not be accurate to reflect the intrinsic quality of a solution due to human factors like personal preferences or biases. In this work, we consider answering the following questions: How to design a mechanism to incentivize workers provide high quality solutions in the presence of such human factors? How to formally study the impact of human factors on workers’ financial incentive to participate? We design a mechanism to incentivize workers to provide high-quality contributions, which is robust to human factors. Our incentive mechanism consists of a “task bundling scheme” and a “rating system”, which reward workers based on requesters’ rating on the solution quality. We propose a probabilistic model to capture human factors, and quantify their impact on the incentive mechanism. We formulate an optimization framework to select appropriate rating system parameters, which can be viewed as a tradeoff between “system efficiency”, i.e., the total number of tasks can be solved given a fixed reward budget, and the “rating system complexity”, which determines the human cognitive cost and time in expressing ratings. We also formulate an optimization framework to select appropriate bundling size, which can tradeoff system efficiency against service delay (i.e., the waiting time to form a task bundle). Finally, we con- uct experiments on a dataset from Elance. Experimental results show that our incentive mechanism achieves at least 99.95 percent of the theoretical maximum system efficiency with a service delay of at most 2.3639 hours. Furthermore, we discover that the rating system in Elance is too complex, and it should be simplified to a binary rating system (i.e., two rating points).
Autors: Hong Xie;John C. S. Lui;
Appeared in: IEEE Transactions on Services Computing
Publication date: Feb 2018, volume: 11, issue:1, pages: 90 - 102
Publisher: IEEE
 
» Incorporation of Prior Knowledge of Signal Behavior Into the Reconstruction to Accelerate the Acquisition of Diffusion MRI Data
Abstract:
Diffusion MRI data are generally acquired using hyperpolarized gases during patient breath-hold, which yields a compromise between achievable image resolution, lung coverage, and number of -values. In this paper, we propose a novel method that accelerates the acquisition of diffusion MRI data by undersampling in both the spatial and -value dimensions and incorporating knowledge about signal decay into the reconstruction (SIDER). SIDER is compared with total variation (TV) reconstruction by assessing its effect on both the recovery of ventilation images and the estimated mean alveolar dimensions (MADs). Both methods are assessed by retrospectively undersampling diffusion data sets (=8) of healthy volunteers and patients with Chronic Obstructive Pulmonary Disease (COPD) for acceleration factors between x2 and x10. TV led to large errors and artifacts for acceleration factors equal to or larger than x5. SIDER improved TV, with a lower solution error and MAD histograms closer to those obtained from fully sampled data for acceleration factors up to x10. SIDER preserved image quality at all acceleration factors, although images were slightly smoothed and some details were lost at x10. In conclusion, we developed and validated a novel compressed sensing method for lung MRI imaging and achieved high acceleration factors, which can be used to increase the amount of data acquired during breath-hold. This methodology is expected to improve the accuracy of estimated lung microstructure dimensions and provide more options in the study of lung diseases with MRI.
Autors: Juan F. P. J. Abascal;Manuel Desco;Juan Parra-Robles;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Feb 2018, volume: 37, issue:2, pages: 547 - 556
Publisher: IEEE
 
» Indented Antenna Arrays for High Isolation: The Growing Interest in Simultaneous-Transmit-and-Receive-Based Full-Duplex Communication Systems
Abstract:
In full-duplex communication systems, reflections of transmitted waves as a result of the antenna mismatch may leak into the receiver and create strong on-site interferences. Such reflections cannot be suppressed by conventional frontend isolation techniques even with ideal circulators. Indented antenna arrays are thus proposed to destructively combine the reflection from each antenna element and prevent them from negatively impacting the receiver sensitivity. The essential idea is to break the symmetry between the transmitting and receiving paths by using an antenna aperture that is curved by indenting the antenna elements. Because of this asymmetry, all of the elements contribute to the wave transmission and reception in phase, whereas the reflections from those elements are out of phase and cancel each other out. With indented antenna configurations, broadband isolation between the transmitting and receiving paths can be achieved for both monostatic and bistatic antenna settings. The improvement is obtained without sacrificing antenna radiation patterns or polarizations. Measured results with a four-element indented quasi-Yagi antenna array operating from 3.2 to 3.4 GHz are presented. The results have demonstrated a 13-dB improvement on the antenna return loss of a single array, a 15-dB transmit/receive isolation improvement in a monostatic array, including circulators, and a 20-dB transmit/receive isolation improvement for a bistatic array without using circulators.
Autors: Qiang Xu;Mathew Biedka;Yuanxun Ethan Wang;
Appeared in: IEEE Antennas and Propagation Magazine
Publication date: Feb 2018, volume: 60, issue:1, pages: 72 - 80
Publisher: IEEE
 
» Independently Tunable Ultrasharp Double Fano Resonances in Coupled Plasmonic Resonator System
Abstract:
A coupled plasmonic resonator system is investigated by both the finite element method (FEM) and the multimode interference coupled-mode theory (MICMT). The resonator system is made up of a cross rectangular cavity on two metal–insulator–metal (MIM) waveguides separated by a metal baffle. The asymmetric cross rectangular in the structure induces an additional Fano resonance in the transmission spectrum, which only single Fano resonance arises in the structure consisted of the symmetric cross-rectangular cavities. The positions of double Fano resonances in the transmission spectrum can be manipulated independently by changing the size of the horizontal rectangular cavity. It is of great help for designing photonic component at fixed wavelengths. The proposed structure based on our independently tunable double Fano resonances has a wide application in the sensors, splitters, switches, and nano-photonic integrated circuits devices.
Autors: Hongxue Fu;Shilei Li;Yilin Wang;Gang Song;Pengfei Zhang;Lulu Wang;Li Yu;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 9
Publisher: IEEE
 
» Index-Based Network Aligner of Protein-Protein Interaction Networks
Abstract:
Network Alignment over graph-structured data has received considerable attention in many recent applications. Global network alignment tries to uniquely find the best mapping for a node in one network to only one node in another network. The mapping is performed according to some matching criteria that depend on the nature of data. In molecular biology, functional orthologs, protein complexes, and evolutionary conserved pathways are some examples of information uncovered by global network alignment. Current techniques for global network alignment suffer from several drawbacks, e.g., poor performance and high memory requirements. We address these problems by proposing IBNAL, Indexes-Based Network ALigner, for better alignment quality and faster results. To accelerate the alignment step, IBNAL makes use of a novel clique-based index and is able to align large networks in seconds. IBNAL produces a higher topological quality alignment and comparable biological match in alignment relative to other state-of-the-art aligners even though topological fit is primarily used to match nodes. IBNAL’s results confirm and give another evidence that homology information is more likely to be encoded in network topology than sequence information.
Autors: Ahed Elmsallati;Abdulghani Msalati;Jugal Kalita;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Feb 2018, volume: 15, issue:1, pages: 330 - 336
Publisher: IEEE
 
» Induced Eddy Currents in Simple Conductive Geometries: Mathematical Formalism Describes the Excitation of Electrical Eddy Currents in a Time-Varying Magnetic Field
Abstract:
A complete mathematical formalism is introduced to describe the excitation of electrical eddy currents due to a time-varying magnetic field. The process works by applying a quasistatic approximation to Ampere's law and then segregating the magnetic field into impressed and induced terms. The result is a nonhomogeneous vector Helmholtz equation that can be analytically solved for many practical geometries. Four demonstration cases are then solved under a constant excitation field over all space.
Autors: James R. Nagel;
Appeared in: IEEE Antennas and Propagation Magazine
Publication date: Feb 2018, volume: 60, issue:1, pages: 81 - 88
Publisher: IEEE
 
» Inferring the Functions of Proteins from the Interrelationships between Functional Categories
Abstract:
This study proposes a new method to determine the functions of an unannotated protein. The proteins and amino acid residues mentioned in biomedical texts associated with an unannotated protein can be considered as characteristics terms for , which are highly predictive of the potential functions of . Similarly, proteins and amino acid residues mentioned in biomedical texts associated with proteins annotated with a functional category can be considered as characteristics terms of . We introduce in this paper an information extraction system called IFP_IFC that predicts the functions of an unannotated protein by representing and each functional category by a vector of weights. Each weight reflects the degree of association between a c- aracteristic term and (or a characteristic term and ). First, IFP_IFC constructs a network, whose nodes represent the different functional categories, and its edges the interrelationships between the nodes. Then, it determines the functions of by employing random walks with restarts on the mentioned network. The walker is the vector of . Finally, is assigned to the functional categories of the nodes in the network that are visited most by the walker. We evaluated the quality of IFP_IFC by comparing it experimentally with two other systems. Results showed marked improvement.
Autors: Kamal Taha;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Feb 2018, volume: 15, issue:1, pages: 157 - 167
Publisher: IEEE
 
» Inferring Unknown Biological Function by Integration of GO Annotations and Gene Expression Data
Abstract:
Characterizing genes with semantic information is an important process regarding the description of gene products. In spite that complete genomes of many organisms have been already sequenced, the biological functions of all of their genes are still unknown. Since experimentally studying the functions of those genes, one by one, would be unfeasible, new computational methods for gene functions inference are needed. We present here a novel computational approach for inferring biological function for a set of genes with previously unknown function, given a set of genes with well-known information. This approach is based on the premise that genes with similar behaviour should be grouped together. This is known as the guilt-by-association principle. Thus, it is possible to take advantage of clustering techniques to obtain groups of unknown genes that are co-clustered with genes that have well-known semantic information (GO annotations). Meaningful knowledge to infer unknown semantic information can therefore be provided by these well-known genes. We provide a method to explore the potential function of new genes according to those currently annotated. The results obtained indicate that the proposed approach could be a useful and effective tool when used by biologists to guide the inference of biological functions for recently discovered genes. Our work sets an important landmark in the field of identifying unknown gene functions through clustering, using an external source of biological input. A simple web interface to this proposal can be found at http://fich.unl.edu.ar/sinc/webdemo/gamma-am/.
Autors: Guillermo Leale;Ariel Emilio Bayá;Diego H. Milone;Pablo M. Granitto;Georgina Stegmayer;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Feb 2018, volume: 15, issue:1, pages: 168 - 180
Publisher: IEEE
 
» Influencing Sources for Dark Current Transport and Avalanche Mechanisms in Planar and Mesa HgCdTe p-i-n Electron-Avalanche Photodiodes
Abstract:
In this paper, both planar and mesa homojunction p-i-n HgCdTe electron-avalanche photodiodes (e-APDs) are fabricated and investigated to better understand the dark current transport and electron-avalanche mechanisms of the devices and optimize the structures. The experiment results are agreed well by simulated – characteristics based on established numerical models. Our results show that the multiplication region fabrication process leads to enormous characteristic difference between planar and mesa diodes. Shockley–Read–Hall and trap-assisted tunneling current are the main components of dark current for the planar/mesa junction under low bias voltage, and dark current is mainly influenced by band-to-band tunneling and avalanche current when higher reverse bias is added. In addition, we found that the difference between the uniformity of the electric field distributions in multiplication regions is the primary reason for the differences of the dark current. It was also proved that the dark current of planar e-APDs is dramatically affected by the junction corners, and mesa e-APDs dark current is found to be greatly dependent on the multiplication region thickness. Our work provides a great deal of theoretical basis for dark current formation and the avalanche mechanism of HgCdTe e-APDs.
Autors: Qing Li;Jiale He;Weida Hu;Lu Chen;Xiaoshuang Chen;Wei Lu;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 572 - 576
Publisher: IEEE
 
» Information Spreading Forensics via Sequential Dependent Snapshots
Abstract:
Mining the characteristics of information spreading in networks is crucial in communication studies, network security management, epidemic investigations, etc. Previous works are restrictive because they mainly focused on the information source detection using either a single observation, or multiple but independent observations of the underlying network while assuming a homogeneous information spreading rate. We conduct a theoretical and experimental study on information spreading, and propose a new and novel estimation framework to estimate 1) information spreading rates, 2) start time of the information source, and 3) the location of information source by utilizing multiple sequential and dependent snapshots where information can spread at heterogeneous rates. Our framework generalizes the current state-of-the-art rumor centrality [1] and the union rumor centrality [2]. Furthermore, we allow heterogeneous information spreading rates at different branches of a network. Our framework provides conditional maximum likelihood estimators for the above three metrics and is more accurate than rumor centrality and Jordan center in both synthetic networks and real-world networks. Applying our framework to the Twitter’s retweet networks, we can accurately determine who made the initial tweet and at what time the tweet was sent. Furthermore, we also validate that the rates of information spreading are indeed heterogeneous among different parts of a retweet network.
Autors: Kechao Cai;Hong Xie;John C. S. Lui;
Appeared in: IEEE/ACM Transactions on Networking
Publication date: Feb 2018, volume: 26, issue:1, pages: 478 - 491
Publisher: IEEE
 
» InGaP/AlGaInP Quantum Well Discrete Mode Laser Diode Emitting at 689 nm
Abstract:
A discrete-mode laser diode, fabricated in the In0.6Ga0.4P/AlGaInP multiple quantum well system, emitting a single mode at $lambda =689$ nm is reported. The laser has an ex-facet output power >10 mW at 30 °C and operates mode hop free in the temperature range 0 °C to 50 °C.
Autors: Richard Phelan;Michael Gleeson;Diarmuid Byrne;John O’Carroll;Philip Long;Lina Maigyte;Robert Lennox;Kevin Carney;Chris Herbert;Jim Somers;Brian Kelly;
Appeared in: IEEE Photonics Technology Letters
Publication date: Feb 2018, volume: 30, issue:3, pages: 235 - 237
Publisher: IEEE
 
» Instrumentation and measurement testing in the real-time lab for automation of complex power systems
Abstract:
This paper presents an overview of the portion of the real-time simulation laboratory of the Institute for Automation of Complex Power Systems at RWTH Aachen University, dedicated to the testing of instrumentation, measurement and monitoring applications. Its key feature is the ability to test monitoring systems and complex monitoring methods as integrated systems as well as a set of individual components. This is made possible by testing platforms that accommodate a mix of interoperable real and real-time simulated components and include communications, databases, and protocols that are representative of the field deployment of the monitoring system.
Autors: Ferdinanda Ponci;Abhinav Sadu;Robert Uhl;Markus Mirz;Andrea Angioni;Antonello Monti;
Appeared in: IEEE Instrumentation & Measurement Magazine
Publication date: Feb 2018, volume: 21, issue:1, pages: 17 - 24
Publisher: IEEE
 
» Integrated Design of Event-Triggered Closed-Loop Subspace Predictive Control Scheme
Abstract:
This paper proposes a novel event-triggered closed-loop subspace predictive control algorithm for linear discrete-time systems with an unknown plant model. The integrated observer-based event-triggered system is designed only with the system input and output data. The designed event-triggered law is dependent on the defined input error based on the input-to-state stable Lyapunov (ISS-Lyapunov) function. The receding horizon principle in the typical predictive control is substituted by the event-triggered law, which can considerably reduce the computation load and the time consumption while it maintains its stability and optimality. Moreover, a possible fault detection scheme is also proposed based on the event-triggered law. The simulation results illustrate the effect and the improved performance of the proposed scheme.
Autors: Zhe Li;Guang-Hong Yang;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Feb 2018, volume: 23, issue:1, pages: 80 - 88
Publisher: IEEE
 
» Integrated HVDC Circuit Breakers With Current Flow Control Capability
Abstract:
Two key problems in meshed high-voltage direct current (HVDC) transmission grids are managing line power flows and protection against dc faults. Current flow controllers (CFCs) will be required to balance cable currents in meshed dc grids, in order to prevent individual line power capacity limits restricting overall power flow in the grid. Direct current circuit breakers (DCCBs) will be also required to protect HVDC grids from dc faults. This paper demonstrates that the current flow controller functionality can be added into a hybrid CB's design. This paper proposes integrating an interline CFC into the load commutation switch (LCS) of a hybrid DCCB. The integrated design LCS/CFC is analyzed and a state-space model is derived. The control of the CFC is designed and the performance of the LCS/CFC during normal operation is verified by means of MATLAB Simulink and PSCAD simulations. A comparison of the integrated LCS/CFC and the separate design is given. The case studies show a reduction in total power losses, and improved protection operation times can be achieved.
Autors: Oliver Cwikowski;Joan Sau-Bassols;Bin Chang;Eduardo Prieto-Araujo;Mike Barnes;Oriol Gomis-Bellmunt;Roger Shuttleworth;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 371 - 380
Publisher: IEEE
 
» Integrated Polarized Skylight Sensor and MIMU With a Metric Map for Urban Ground Navigation
Abstract:
This paper presents a novel multi-sensor navigation system for the urban ground vehicle. The integration system can combine the measurements from a polarized skylight sensor, an inertial sensor, and a monocular camera. Utilizing the polarized skylight sensor, we propose a robust orientation algorithm with the total least squares to provide the orientation constraint for the integrating system. In our algorithm, the ambiguity problem of polarized orientation is solved without any other sensor. In order to enhance the algorithm’s robustness in the urban environment, we also propose a real-time method that uses the gradient of the degree of the polarization to remove the obstacles. With a monocular camera, we build a metric map and recognize places in the map to provide the position constraint for the integrating system. We develop the Kalman filter to integrate these constraints with the inertial navigation results to estimate the orientation and position for the ground vehicle. The results demonstrate that our proposed system outperforms other vision-based navigation algorithms–the RMSE of the position error is 2.04 m (0.01% of the travelled distance) and the RMSE of the orientation error is 0.84°. Finally, we present interesting insights gained with respect to the further work in sensors and robotics.
Autors: Chen Fan;Xiaoping Hu;Xiaofeng He;Lilian Zhang;Junxiang Lian;
Appeared in: IEEE Sensors Journal
Publication date: Feb 2018, volume: 18, issue:4, pages: 1714 - 1722
Publisher: IEEE
 
» Integrated Systems-in-Package: Heterogeneous Integration of Millimeter-Wave Active Circuits and Passives in Fan-Out Wafer-Level Packaging Technologies
Abstract:
Recent advances in silicon semiconductor technology with transit and maximum oscillation frequencies above 300 GHz have enabled the integration of complex transceiver front ends operating in the millimeter-wave (mmW) regime for a variety of applications. Among these, the most prominent frequency ranges (and their associated applications) are currently the 60-GHz short-range communication frequency band [1]-[2] and E-band wireless back-haul solutions [3]-[4], as well as the 76-81-GHz band for automotive radar sensor realizations [5]-[6].
Autors: Amelie Hagelauer;Maciej Wojnowski;Klaus Pressel;Robert Weigel;Dietmar Kissinger;
Appeared in: IEEE Microwave Magazine
Publication date: Feb 2018, volume: 19, issue:1, pages: 48 - 56
Publisher: IEEE
 
» Integrated Tin Monoxide P-Channel Thin-Film Transistors for Digital Circuit Applications
Abstract:
High-performance integrated tin monoxide bottom-gate staggered p-channel thin-film transistors (TFTs) are realized and reported. The active layer has been formed by thermal vacuum evaporation and rapid thermal annealing under a continuous nitrogen flow, resulting in field-effect mobilities up to 1.6 cm2/() and contact resistances of around . The integration of these TFTs in elementary building blocks for digital circuit applications such as inverters and ring-oscillators is demonstrated, resulting in stage delays down to 300 ns. Furthermore, a unipolar p-type-only 8-bit radio frequency identification code generator is realized, achieving 12.2 kb/s and comprising 294 tin monoxide TFTs.
Autors: Maarten Rockelé;Karolien Vasseur;Alexander Mityashin;Robert Müller;Adrian Chasin;Manoj Nag;Ajay Bhoolokam;Jan Genoe;Paul Heremans;Kris Myny;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 514 - 519
Publisher: IEEE
 
» Integration of Contextual Knowledge in Unsupervised Subpixel Classification: Semivariogram and Pixel-Affinity Based Approaches
Abstract:
This letter investigates the use of coarse-image features for predicting class labels at a given finer spatial scale. In this regard, two unsupervised subpixel mapping approaches, a semivariogram method, and a pixel-affinity based method are proposed. Furthermore, segmentation-based spectral unmixing is explored so as to address the spectral variability and nonconvexity of classes. In addition, the gradient information is employed to resolve uncertainties in the unmixing process. The proposed modifications based on pixel-affinity and semivariogram have produced an accuracy improvement of 5% or more over the state-of-the-art approaches.
Autors: P. V. Arun;K. M. Buddhiraju;A. Porwal;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Feb 2018, volume: 15, issue:2, pages: 262 - 266
Publisher: IEEE
 
» Integration of LoRaWAN and 4G/5G for the Industrial Internet of Things
Abstract:
Current forecasts predict that the Industrial Internet of Things will account for about 10 billion devices by 2020. Simultaneously, unlicensed low-power wide area networks are gaining momentum due to their low cost, low power, and long range characteristics, which are suitable for many IIoT applications, in addition to the usage of unlicensed bands. In this article, a solution is proposed to seamlessly integrate LoRaWAN, an open and standardized LPWAN technology, with 4G/5G mobile networks, thus allowing mobile network operators to reutilize their current infrastructures. This proposal is transparent to LoRaWAN end devices and to the EPC, since only the LoRaWAN gateway needs to be modified. The gateway acts as an evolved Node B from the core network perspective, implementing part of the eNB protocol stack. All data packets transported over the core network are both encrypted and integrity protected, hence achieving end-toend security. As a proof of concept, this solution has been implemented and validated with an open source EPC.
Autors: Jorge Navarro-Ortiz;Sandra Sendra;Pablo Ameigeiras;Juan M. Lopez-Soler;
Appeared in: IEEE Communications Magazine
Publication date: Feb 2018, volume: 56, issue:2, pages: 60 - 67
Publisher: IEEE
 
» Intelligent Detail Enhancement for Exposure Fusion
Abstract:
Multiscale exposure fusion is a fast approach to fuse several differently exposed images captured at the same high dynamic range (HDR) scene into a high-quality low-dynamic range (LDR) image. The fused image is expected to include all details of the input images. However the details in the brightest and darkest regions are usually not well preserved. Adding details that are extracted from the input images to the fused image is an efficient approach to overcome the problem. In this paper a new gradient domain weighted least square based image smoothing algorithm is proposed to extract the details in the brightest and darkest regions of the HDR scene. The extracted details are then added to an image that is produced using an edge-preserving smoothing pyramid based multiscale exposure fusion algorithm. Experimental results show that the proposed detail enhanced exposure fusion algorithm can preserve details in saturated regions especially the brightest regions better than the state-of-the-art multiscale exposure fusion algorithms.
Autors: Fei Kou;Zhe Wei;Weihai Chen;Xingming Wu;Changyun Wen;Zhengguo Li;
Appeared in: IEEE Transactions on Multimedia
Publication date: Feb 2018, volume: 20, issue:2, pages: 484 - 495
Publisher: IEEE
 
» Interaction Between Inertia, Viscosity, and Elasticity in Soft Robotic Actuator With Fluidic Network
Abstract:
Soft robotics is an emerging bioinspired concept of actuation, with promising applications for robotic locomotion and manipulation. Focusing on actuation by pressurized embedded fluidic networks, existing works examine quasi-static locomotion by inviscid fluids. This paper presents analytic formulation and closed-form solutions of an elastic actuator with pressurized fluidic networks, while accounting for the effects of solid inertia and elasticity, as well as fluid viscosity. This allows modeling the system's step response and frequency response as well as suggesting mode elimination and isolation techniques. The theoretical results describing the viscous–elastic–inertial dynamics of the actuator are illustrated by experiments. The approach presented in this paper may pave the way for the design and implementation of soft robotic legged locomotion that exploits dynamic effects.
Autors: Benny Gamus;Lior Salem;Eran Ben-Haim;Amir D. Gat;Yizhar Or;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 81 - 90
Publisher: IEEE
 
» Interference Management for In-Band Full-Duplex Vehicular Access Networks
Abstract:
We consider in-band full-duplex (FD) vehicular access networks in which a FD vehicular access point (AP) with high mobility simultaneously supports half-duplex (HD) downlink and uplink users with low mobility. We assume no self-interference due to FD operation at the AP and no channel state information known at the transmit side (no channel state information at the transmitter side). We completely characterize the sum degrees of freedom (DoF) by proposing an optimal blind interference alignment scheme, which exploits the difference of channel's temporal correlations between the AP and users, and establishing the matching upper bound on the sum DoF. Performance evaluation shows that the proposed scheme improves the sum rate at the finite signal-to-noise ratio regime compared to the conventional HD system.
Autors: Minho Yang;Sang-Woon Jeon;Dong Ku Kim;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1820 - 1824
Publisher: IEEE
 
» Interference Modeling in an Urban Microcell With Full-Dimensional MIMO
Abstract:
In this paper, we study the uplink performance in a three-dimensional (3-D) urban microcell. The single-antenna users are distributed according to a 3-D Poisson point process inside the cell. Each user has a probability to experience a line-of-sight (LoS) channel or a fading channel, and transmits to the multiantenna base station (BS) utilizing fractional power control. The BS deploys a large 2-D planar antenna array and performs 3-D beamforming (BF) to receive the signals of all users in the cell sector. Under such a setting, we study the interference incurred by the cochannel users in the cell sector to a randomly located target user. In particular, we show that the interference incurred by the LoS interferers to a LoS target user is associated with the 3-D BF antenna pattern. This type of interference is determined by the separation between the locations of the target user and interferer, and hence it is heavily dependent on the cell geometry. We exploit the massive MIMO regime and present a good approximation to model the LoS interference. We further resort to stochastic geometry to analyze the coverage probability and the rate per user in the cell.
Autors: Yeqing Hu;Yi Hong;Jamie Evans;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1347 - 1362
Publisher: IEEE
 
» Interferometric Optical Gyroscope Based on an Integrated Si3N4 Low-Loss Waveguide Coil
Abstract:
We describe the measurement and characterization of an interferometric optical gyroscope that uses an integrated 3-m large-area silicon nitride waveguide coil with waveguide loss <0.78 dB/m that is compatible with wafer-scale integration. The angle random walk and bias instability were measured to be 8.52°/h1/2 and 58.7°/h, respectively. The measured performance is comparable to that of a commercial rate grade gyroscope, demonstrating that chip-scale integration is a feasible path to low cost, low power, compact implementation of optical gyroscope, and realization of longer coils will expand use of this technology to more demanding navigation applications.
Autors: Sarat Gundavarapu;Michael Belt;Taran A. Huffman;Minh A. Tran;Tin Komljenovic;John E. Bowers;Daniel J. Blumenthal;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2018, volume: 36, issue:4, pages: 1185 - 1191
Publisher: IEEE
 
» Interleaving and Error Concealment to Mitigate the Impact of Packet Loss in Resource-Constrained TDLAS/WMS Data Acquisition
Abstract:
Tomographic imaging of pollutant gas emissions from aeroengines is attractive for the development of engines and fuels. A 126-beam tomographic setup has previously been proposed utilizing tunable diode laser absorption spectroscopy aiming for fast spatially resolved measurement of CO2 concentration. The custom data acquisition system uses a distributed architecture with at-site digital lock-in amplification, but remains resource constrained. A calibrated model is fitted to quadrature the first and second harmonic data, however, packet loss in ethernet and/or wireless networks can cause nondeterministic errors in the curve fitting and increased errors in recovered gas concentrations. Packet loss in this case, is a product of the available protocol, the high-vibration and high-noise industrial testing environment, the high network utilization expected, and the interrupt behavior of the embedded microprocessors. In this paper, the structure of the data acquisition system and the curve fitting approach are briefly discussed. Packet loss is then performed numerically to demonstrate the introduction of errors, as this cannot be swept experimentally without introducing other factors and increasing additive noise. An interleaving and error concealment mitigation approach is reported, that reduces this error, and can be applied to other resource-constrained remote acquisition systems such as Internet of Things applications. This approach is evaluated over parameters including extent of packet loss, interleaving ratio, and number of wavelength samples per packet. Viewing packet loss as a measurement SNR modifier, interleaving is shown to recover some SNR, but is ultimately limited. Processing of the received data using error concealment prior to spectrographic fitting is shown to increase tolerance.
Autors: Edward M. D. Fisher;Thomas Benoy;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Feb 2018, volume: 67, issue:2, pages: 439 - 448
Publisher: IEEE
 
» Intermediate DC-Link Capacitor Reduction in a Two-Stage Cascaded AC/DC Converter for More Electric Aircrafts
Abstract:
In this paper, an innovative method to minimize the intermediate dc-link capacitance in a cascaded two-stage combination of a three-phase six-switch power factor correction (PFC) and phase-shifted full-bridge (PSFB) dc/dc stage is introduced and analyzed. The proposed strategy has a significant impact on the minimization of the overall system weight and volume. Fundamentally, the method is based on minimizing the switching fundamental component of the dc-link current and is established by imposing a separate constraint on the phase duty ratios without compromising the unity PFC action. Furthermore, the control loop takes care of regulating the intermediate dc-link voltage along with the final output voltage. A 6 kW laboratory prototype of the integrated three-phase PFC and PSFB dc/dc as a part of auxiliary power unit in more-electric airplanes is developed and designed to validate the proposed algorithm. The experimental results show a conversion efficiency of 95.4% at full load, input total harmonic distortion of 4.1%, power factor of 0.998, output voltage ripple of ±1%, and a reduction of dc-link capacitor by 60%.
Autors: Ayan Mallik;Alireza Khaligh;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 935 - 947
Publisher: IEEE
 
» Internet of things for smart ports: Technologies and challenges
Abstract:
Nowadays, the Internet of Things (IoT) can be considered an important technological revolution related to smart cities, smart homes, smart factories and smart ports implementations. As the presence of smart sensing systems in ports becomes a reality, different operation areas are working today in automatic mode. Examples of challenging projects related to smart ports in the IoT era can be found from Europe to Asia, to Australia, and to North America; in all of these new architecture implementations, sensing technologies play a key role. This paper highlights the main requirements and the key ideas for each ports, sensing solution and also the challenges related to the calibration and testing of distributed sensing systems associated with the main equipment that compose the world largest ports, such as quayside cranes, automated guided vehicles for container handling and yard cranes. Details of the architecture and operations and sensing systems for smart ports are described. Communication standards for smart ports are discussed, and smart ports implementation examples regarding structural health monitoring are considered. Conclusions and future research opportunities in the IoT era are addressed in the final section of the paper.
Autors: Yongsheng Yang;Meisu Zhong;Haiqing Yao;Fang Yu;Xiuwen Fu;Octavian Postolache;
Appeared in: IEEE Instrumentation & Measurement Magazine
Publication date: Feb 2018, volume: 21, issue:1, pages: 34 - 43
Publisher: IEEE
 
» Interval Type-2 Mutual Subsethood Fuzzy Neural Inference System (IT2MSFuNIS)
Abstract:
This paper presents an interval type-2 mutual subsethood fuzzy neural inference system (IT2MSFuNIS). A mutual subsethood measure between two interval type-2 fuzzy sets (IT2 FS) has been derived and has been used in determining the similarity between the IT2 FS inputs and IT2 FS antecedents. The consequent weights are taken to be interval sets. The inputs to the system are fuzzified into IT2 FSs with Gaussian primary membership function having fixed center and uncertain variance. Aggregation of type-2 mutual subsethood based activation spreads is performed using product operator. The output is obtained using simplified type-reduction followed by defuzzification. The system learns using memetic procedure involving differential evolution for global search and gradient descent for local exploitation in solution space. The mathematical modeling and empirical studies of IT2MSFuNIS bring forth its efficacy in problems pertaining to function approximation, time-series prediction, control, and classification. Comparisons with other type-1 and type-2 neuro-fuzzy systems verify that IT2MSFuNIS compares excellently with other models with a performance better than most of them both in terms of total number of trainable parameters and result accuracy. Empirical studies indicate the intelligent decision making capability of the proposed model. The main contribution of this paper lies in the identification of mutual subsethood to find out the correlation between IT2 FSs and to find out its applicability in diverse application domains. The improved performance of the proposed method can be attributed to the better contrast handling capacity of mutual subsethood method and uncertainty handling capacity of IT2 FSs. The integration of mutual subsethood with interval type-2 fuzzy logic puts forth a novel model with various merits as demonstrated amply with the help of well-known problems reported in the literature.
Autors: Vuppuluri Sumati;C. Patvardhan;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Feb 2018, volume: 26, issue:1, pages: 203 - 215
Publisher: IEEE
 
» Intraoperative Tissue Young’s Modulus Identification During Needle Insertion Using a Laterally Actuated Needle
Abstract:
Needle insertion is a common minimally invasive medical procedure used for therapy and diagnosis. Among the therapeutic procedures is prostate brachytherapy, during which needle insertion is applied to implant radioactive seeds within the prostate. During insertion, the needle tends to deflect from a desired straight path, thus causing misplacement of the seeds. While currently the needle is steered manually to correct for needle deflection, robotic assistance can be used toward this goal. A requirement for accurate robotic needle steering is needle deflection estimation or prediction obtained from needle deflection modeling. Various mechanics-based deflection models based on needle–tissue interactions have been introduced in the literature. Many models require the tissue Young’s modulus as a parameter input that can be measured or quantified using methods of varying limitations with regard to complexity or access in the operating room. This paper proposes an intraoperative method for the identification of tissue Young’s modulus using lateral actuation of the needle. The needle–tissue system’s response in terms of needle deflection and thus tissue displacement is observed during lateral needle displacement. The tissue Young’s modulus is then identified based on the energy stored in the needle–tissue system. Using this method, the actuated needle itself is the tool used to obtain the tissue Young’s modulus, facilitating clinical implementation. Experimental studies are presented to confirm a high accuracy of the identified tissue Young’s modulus when compared with an independent measurement. Moreover, the prediction accuracy of a deflection model that is calibrated with the proposed method is verified experimentally.
Autors: Thomas Lehmann;Carlos Rossa;Nawaid Usmani;Ron S. Sloboda;Mahdi Tavakoli;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Feb 2018, volume: 67, issue:2, pages: 371 - 381
Publisher: IEEE
 
» Intrinsically Safe Grounding Systems and Global Grounding Systems
Abstract:
This paper introduces a characterization of grounding systems (GSs) and defines their condition of “conventionally safe” and “intrinsically safe.” A single GS and a set of GSs are intrinsically safe if they guarantee touch/step voltages permanently permissible for an assigned ground fault value. A new definition of global grounding systems (GGSs) is proposed, revising that offered by the Standards IEC 61936-1/EN 50522. A safety criterion, useful for urban and industrial areas with reduced accessibility, allows identifying the safety zone of influence, and the intrinsically safe condition of a single GS and of a GGS, constituted by a set of interconnected single GSs.
Autors: Giuseppe Parise;Luigi Parise;Luigi Martirano;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 25 - 31
Publisher: IEEE
 
» Introducing a Stable Bootstrap Validation Framework for Reliable Genomic Signature Extraction
Abstract:
The application of machine learning methods for the identification of candidate genes responsible for phenotypes of interest, such as cancer, is a major challenge in the field of bioinformatics. These lists of genes are often called genomic signatures and their linkage to phenotype associations may form a significant step in discovering the causation between genotypes and phenotypes. Traditional methods that produce genomic signatures from DNA Microarray data tend to extract significantly different lists under relatively small variations of the training data. That instability hinders the validity of research findings and raises skepticism about the reliability of such methods. In this study, a complete framework for the extraction of stable and reliable lists of candidate genes is presented. The proposed methodology enforces stability of results at the validation step and as a result, it is independent of the feature selection and classification methods used. Furthermore, two different statistical tests are performed in order to assess the statistical significance of the observed results. Moreover, the consistency of the signatures extracted by independent executions of the proposed method is also evaluated. The results of this study highlight the importance of stability issues in genomic signatures, beyond their prediction capabilities.
Autors: Nikolaos-Kosmas Chlis;Ekaterini S. Bei;Michalis Zervakis;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Feb 2018, volume: 15, issue:1, pages: 181 - 190
Publisher: IEEE
 
» Introducing the Internet of Things Department
Abstract:
The Internet of Things is a new department with the mission of presenting fresh ideas and applications from a practitioner point of view. The authors are interested in showcasing articles about real, implemented Internet of Things (IoT) systems.
Autors: Phillip A. Laplante;Ben Amaba;
Appeared in: IT Professional
Publication date: Feb 2018, volume: 20, issue:1, pages: 15 - 18
Publisher: IEEE
 
» Introducing the IT Economics Department
Abstract:
The new IT Economics department seeks to advance the understanding of various microeconomic and macroeconomic issues that IT managers need to examine in their decisions to adopt and implement information and communications technology-related systems, services, processes, and practices.
Autors: Nir Kshetri;
Appeared in: IT Professional
Publication date: Feb 2018, volume: 20, issue:1, pages: 83 - 87
Publisher: IEEE
 
» Introducing the Student Forum Column
Abstract:
Student Forum is a new column that intends to connect IT students with industry, government, and academia.
Autors: Gustavo Rossi;
Appeared in: IT Professional
Publication date: Feb 2018, volume: 20, issue:1, pages: 80 - 82
Publisher: IEEE
 
» Introduction to the IEEE CIS TC on Smart World (SWTC) [Society Briefs]
Abstract:
Presents information on the CIS Smart World.
Autors: Jianhua Ma;Cesare Alippi;Laurence T. Yang;Huansheng Ning;Kevin I-Kai Wang;
Appeared in: IEEE Computational Intelligence Magazine
Publication date: Feb 2018, volume: 13, issue:1, pages: 7 - 9
Publisher: IEEE
 
» Introduction to the Issue on Machine Learning for Cognition in Radio Communications and Radar
Abstract:
Autors: S. Kokalj-Filipovic;M. S. Greco;H. V. Poor;G. Stantchev;L. Xiao;
Appeared in: IEEE Journal of Selected Topics in Signal Processing
Publication date: Feb 2018, volume: 12, issue:1, pages: 3 - 5
Publisher: IEEE
 
» Introduction to the Special Issue on Applications of Mechatronic and Embedded Systems (MESA) in ITS
Abstract:
Embedded systems result from the integration between mechanical and electronic components (hardware) and the information-driven functions (software). Embedded systems play a key role in the development of mechatronic systems, which involves finding an optimal balance between the basic mechanical structure, sensor and actuators, automatic digital information processing and control.
Autors: Massimo Bertozzi;Bo Chen;Primo Zingaretti;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Feb 2018, volume: 19, issue:2, pages: 530 - 532
Publisher: IEEE
 
» Investigating Route Cache in Named Data Networking
Abstract:
Named data networking is a new communication paradigm for the future networking architecture, which shifts the networking from a host-oriented architecture to an information-centric one. Its data transmission is realized via name-based routing and forwarding. This, however, brings severe challenges to the scalability of the forwarding information base (FIB) because the name space is infinite and can be several orders of magnitude larger than the IP counterpart. This letter tries to mitigate the FIB explosion problem and achieve high-speed forwarding by adding route cache to the FIB design. We proposed two approaches to tackle the cache hiding problem rooted from the longest prefix matching on names of arbitrary length: the atomic caching that groups multiple overlapping prefixes as a unit for cache operation, and the on-the-fly caching that caches only the most specific prefixes. Trace-driven simulation using an HTTP request trace from China Mobile demonstrated the feasibility and effectiveness of our design.
Autors: Xin Chen;Guoqiang Zhang;Huajun Cui;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 296 - 299
Publisher: IEEE
 
» Investigation and Comparison of $varphi $ -OTDR and OTDR-Interferometry via Phase Demodulation
Abstract:
We investigate and compare the -optical time domain reflectometry (OTDR) and OTDR-interferometry methods, both using phase demodulation, for distributed acoustic sensing. By theoretical analysis and experiments we show that, while both -OTDR and OTDR-interferometry give proper instantaneous amplitude, frequency, and phase properties of the acoustic signal, OTDR-interferometry produces larger signals and offers higher sensitivity, better signal-to-noise-ratio, and larger demodulated signal width than -OTDR due to the introduction of the interferometer. This work enables the selection of the better method for distributed acoustic sensing for different situations of surface, seabed, and downhole environments.
Autors: Chen Wang;Ying Shang;Wen-An Zhao;Xiao-Hui Liu;Chang Wang;Gang-Ding Peng;
Appeared in: IEEE Sensors Journal
Publication date: Feb 2018, volume: 18, issue:4, pages: 1501 - 1505
Publisher: IEEE
 
» Investigation of Cycling-Induced Dummy Cell Disturbance in 3D NAND Flash Memory
Abstract:
The disturbance mechanism of dummy cell during memory cell cycling has been investigated in 3D NAND flash. Edge dummy cell (DMY) threshold voltage increasing was observed during cell program and erase cycling, which leads to a reduced string current and read failure. According to experiment and TCAD analysis, two mechanisms were identified to contribute to the dummy disturbance: one is the tunneling of electrons from the adjacent gate to the trapping layer during cell erase condition, which was also observed in 2D NAND; the other one is the lateral charge spreading from the trapping layer of edge cell to DMY, which is a new observation for the junction-less 3D NAND with continuous nitride trapping layer. Furthermore, an optimal DMY bias scheme under erase operation is demonstrated to suppress the disturbance.
Autors: Xingqi Zou;Lei Jin;Dandan Jiang;Yu Zhang;Guoxing Chen;Zongliang Huo;
Appeared in: IEEE Electron Device Letters
Publication date: Feb 2018, volume: 39, issue:2, pages: 188 - 191
Publisher: IEEE
 
» Investigation of Porous Silicon-Based Edge Termination for Planar-Type TRIAC
Abstract:
This paper aims to investigate a porous silicon (PS)-based edge termination for planar type ac switch. TRIAC device prototypes, specifically dedicated to evaluate blocking performances, are fabricated by integrating electrochemical etching in device processing. A mixed porous morphology containing micro-, meso-, and macropores is obtained in a p-Type through-wafer-diffused via after anodization. The fabricated prototypes show PS-dependent blocking capabilities. The possible impacts of the anodization conditions and the physical features of PS on the electrical characteristics are discussed in detail. Low leakage currents () have been demonstrated up to several hundred voltages for both bias polarities. The forward blocking voltage decreases with increasing PS thickness, while an opposite trend is observed for the reverse blocking voltage. This paper confirms the interest of PS as a potential insulating material for power device manufacture.
Autors: Bin Lu;Samuel Ménard;Benjamin Morillon;Daniel Alquier;Gaël Gautier;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 655 - 659
Publisher: IEEE
 
» Investigation of Using IEC 61850-Sampled Values for Implementing a Transient-Based Protection Scheme for Series-Compensated Transmission Lines
Abstract:
This paper investigates the applicability of IEC 61850-9-2 LE-sampled values in transients-based protection by implementing a line protection intelligent electronic device (IED), incorporating a transients-based hybrid protection algorithm suitable for series-compensated transmission lines. The IED is capable of subscribing, decoding, and processing sampled values to be used in the implemented protection algorithms. The proposed method of protection can distinguish between internal and external faults by comparing the polarities of wavelet coefficients of the line currents at either end of the line. The power system section, which the proposed protection scheme is tested upon, is implemented in a real-time digital simulator. Attention is given to replicate the constraints faced by an actual relay in the implementations of the IED. The results indicate that IEC 61850-sampled values can be effectively used in a transients-based protection scheme that is capable of operating under challenging conditions.
Autors: Sachintha Kariyawasam;Athula D. Rajapakse;Nuwan Perera;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 93 - 101
Publisher: IEEE
 
» Investigation on Current Crowding Effect in IGBTs
Abstract:
This paper investigates the influences of various topside cell structures of insulated gate bipolar transistor (IGBT) on the current crowding effect during high current turn-OFF by symmetrical multicell numerical simulations. It is observed that lower breakdown electric field in the drift region can reduce the negative differential resistance in the forward blocking curve and therefore suppress the current crowding effect during high current turn-OFF. We refer to this characteristic as the self-suppressing current crowding effect (SSCCE). Different topside cell structures of IGBT have considerable influence on the SSCCE. A modest increment of the SSCCE by proper topside structure design provides an alternative solution to improve the ruggedness of IGBT, especially for the strong punchthrough or low current gain IGBTs.
Autors: Fei Yang;Hong Chen;Xiaoli Tian;Yun Bai;Yangjun Zhu;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 636 - 640
Publisher: IEEE
 
» IoT Goes Nuclear: Creating a Zigbee Chain Reaction
Abstract:
In this article, we describe a new type of attack on IoT devices, which exploits their ad hoc networking capabilities via the Zigbee wireless protocol, and thus cannot be monitored or stopped by standard Internet-based protective mechanisms. We developed and verified the attack using the Philips Hue smart lamps as a platform, by exploiting a major bug in the implementation of the Zigbee Light Link protocol, and a weakness in the firmware update process. By plugging in a single infected lamp anywhere in the city, an attacker can create a chain reaction in which a worm can jump from any lamp to all its physical neighbors, and thus stealthily infect the whole city if the density of smart lamps in it is high enough. This makes it possible to turn all the city’s smart lights on or off, to brick them, or to use them to disrupt nearby Wi-Fi transmissions.
Autors: Eyal Ronen;Adi Shamir;Achi-Or Weingarten;Colin O’Flynn;
Appeared in: IEEE Security & Privacy
Publication date: Feb 2018, volume: 16, issue:1, pages: 54 - 62
Publisher: IEEE
 
» iRazor: Current-Based Error Detection and Correction Scheme for PVT Variation in 40-nm ARM Cortex-R4 Processor
Abstract:
This paper presents iRazor, a lightweight error detection and correction approach, to suppress the cycle time margin that is traditionally added to very large scale integration systems to tolerate process, voltage, and temperature variations. iRazor is based on a novel current-based detector, which is embedded in flip-flops on potentially critical paths. The proposed iRazor flip-flop requires only three additional transistors, yielding only 4.3% area penalty over a standard D flip-flop. The proposed scheme is implemented in an ARM Cortex-R4 microprocessor in 40 nm through an automated iRazor flip-flop insertion flow. To gain an insight into the effectiveness of the proposed scheme, iRazor is compared to other popular techniques that mitigate the impact of variations, through the analysis of the worst case margin in 40 silicon dies. To the best of the authors’ knowledge, this is the first paper that compares the measured cycle time margin and the power efficiency improvements offered by frequency binning and various canary approaches. Results show that iRazor achieves 26%–34% performance gain and 33%–41% energy reduction compared to a baseline design across the 0.6- to 1-V voltage range, at the cost of 13.6% area overhead.
Autors: Yiqun Zhang;Mahmood Khayatzadeh;Kaiyuan Yang;Mehdi Saligane;Nathaniel Pinckney;Massimo Alioto;David Blaauw;Dennis Sylvester;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2018, volume: 53, issue:2, pages: 619 - 631
Publisher: IEEE
 
» ISAR Imaging Algorithm of Multiple Targets with Complex Motions Based on the Fractional Tap Length Keystone Transform
Abstract:
Complex motions of targets cause migration through resolution cells which leads to the inverse synthetic aperture radar (ISAR) image blurred and makes difficulties to follow-up work such as identification, recognition, and classification. In this paper, a novel ISAR imaging algorithm based on the fractional tap length keystone transform (FTLKT) is proposed for multiple targets with complex motions. In noncooperation case, different targets behave variously. For phase coupling of different orders, the proposed algorithm first employs FTLKT to achieve decoupling of the frequency and slow time variable, then detection of Doppler peaks is applied for ambiguity resolution of different targets. According to this, focused ISAR images of different targets are obtained. Simulation results demonstrate the validity of the proposed algorithm.
Autors: Jia Zhao;Min Zhang;Xin Wang;
Appeared in: IEEE Transactions on Aerospace and Electronic Systems
Publication date: Feb 2018, volume: 54, issue:1, pages: 64 - 76
Publisher: IEEE
 
» Isolation Enhancement in Dual-Band Microstrip Antenna Array Using Asymmetric Loop Resonator
Abstract:
This letter presents the design of a wideband decoupling element for mutual coupling reduction in microstrip antenna arrays. The proposed decoupling unit cell consists of an asymmetric loop resonator with a coupled microstrip line for wide stopband characteristics from 2 to 5 GHz. The bandgap characteristic of the decoupling element is analyzed, and the results are presented. Furthermore, the resonator is deployed in a two-element dual-band microstrip antenna array, and mutual coupling reduction is demonstrated. The decoupling unit cell has a lateral dimension of 2.84 mm and hence enables the packing of antenna elements in very close proximity with reduced mutual coupling. The proposed solution offers additional isolation greater than 15 dB in a V-slot loaded dual-band antenna with edge-to-edge element spacing of . The prototype dual-band antenna array with decoupling element is fabricated, and the simulation results are validated using experimental measurements.
Autors: B. Lakshmi Dhevi;Kuttathati Srinivasan Vishvaksenan;Kalidoss Rajakani;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 238 - 241
Publisher: IEEE
 
» Isolation Improvement Techniques for Wideband Millimeter-Wave Repeaters
Abstract:
Two passive approaches for improving the isolation between flush-mounted transmitting (TX) and receiving (RX) antennas over 45–110 GHz are investigated. Both configurations exploit a reactive impedance surface (RIS) that suppresses TM polarized surface waves propagating on the ground plane between the TX and RX antennas. Quarter-wavelength corrugated one-dimensional (1-D) RIS is shown to improve isolation by ∼20 dB in an octave bandwidth (45–90 GHz), whereas concentric corrugations around the antennas improve isolation over the same bandwidth with better antenna radiation characteristics at the low end. On the other hand, an isolation improvement of ∼15 dB over the entire bandwidth is obtained with an array of grounded circular patches 2-D RIS. Computational studies are validated with measurements of quad-ridge horns with 3-D printed corrugations and printed circuit board 2-D RIS patches.
Autors: Sara Manafi;Muhannad A. Al-Tarifi;Dejan S. Filipovic;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 355 - 358
Publisher: IEEE
 
» ISOMAP-Based Spatiotemporal Modeling for Lithium-Ion Battery Thermal Process
Abstract:
The real-time monitoring of temperature distribution in lithium-ion batteries (LIBs) is crucial for their safety and optimal operation in electrical vehicles. An accurate and effective thermal model is needed for online temperature monitoring since limited sensors are available in vehicle application. In this paper, a data-based spatiotemporal modeling method is researched for online estimation of temperature distribution of LIBs. First, Isometric Mapping (ISOMAP) method is used for time/space separation and model reduction. Then, the low-dimensional representation can be obtained in terms of ISOMAP based mapping functions. The unknown temporal dynamics in the low-dimensional space can be approximated using neural network model with parameters trained using extreme learning machine (ELM) algorithm. Finally, the spatiotemporal model of the thermal process can be reconstructed by integrating the neural network model and the mapping functions. The generalization bound of the proposed spatiotemporal model can be analyzed using Rademacher complexity. Simulation results showed that the proposed modeling method can model the LIB thermal process very well.
Autors: Kang-Kang Xu;Han-Xiong Li;Zhen Liu;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Feb 2018, volume: 14, issue:2, pages: 569 - 577
Publisher: IEEE
 
» Isomorphic Multiplicative Transitivity for Intuitionistic and Interval-Valued Fuzzy Preference Relations and Its Application in Deriving Their Priority Vectors
Abstract:
Intuitionistic fuzzy preference relations (IFPRs) are used to deal with hesitation, while interval-valued fuzzy preference relations (IVFPRs) are for uncertainty in multicriteria decision making (MCDM). This paper aims to explore the isomorphic multiplicative transitivity for IFPRs and IVFPRs, which builds the substantial relationship between hesitation and uncertainty in MCDM. To do that, the definition of the multiplicative transitivity property of IFPRs is established by combining the multiplication of intuitionistic fuzzy sets and Tanino's multiplicative transitivity property of fuzzy preference relations. It is proved to be isomorphic to the multiplicative transitivity of IVFPRs derived via Zadeh's extension principle. The use of the multiplicative transitivity isomorphism is twofold: 1) to discover the substantial relationship between IFPRs and IVFPRs, which will bridge the gap between hesitation and uncertainty in MCDM problems; and 2) to strengthen the soundness of the multiplicative transitivity property of IFPRs and IVFPRs by supporting each other with two different reliable sources, respectively. Furthermore, based on the existing isomorphism, the concept of multiplicative consistency for IFPRs is defined through a strict mathematical process, and it is proved to satisfy the following several desirable properties: weak transitivity, max–max transitivity, and center-division transitivity. A multiplicative consistency-based multiobjective programming (MOP) model is investigated to derive the priority vector from an IFPR. This model has the advantage of not losing information, as the priority vector representation coincides with that of the input information, which was not the case with the existing methods, where crisp priority vectors were derived as a consequence of the modeling transitivity just for the intuitionistic membership function and not for the intuitionistic nonmembership fun- tion. Finally, a numerical example concerning green supply selection is given to validate the efficiency and practicality of the proposed multiplicative consistency MOP model.
Autors: Jian Wu;Francisco Chiclana;Huchang Liao;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Feb 2018, volume: 26, issue:1, pages: 193 - 202
Publisher: IEEE
 
» IT Formulae for Gamma Target: Mutual Information and Relative Entropy
Abstract:
In this paper, we introduce new Stein identities for gamma target distribution as well as a new non-linear channel specifically designed for gamma inputs. From these two ingredients, we derive an explicit and simple formula for the derivative of the input-output mutual information of this non-linear channel with respect to the channel quality parameter. This relation is reminiscent of the well-known link between the derivative of the input-output mutual information of additive Gaussian noise channel with respect to the signal-to-noise ratio and the minimum mean-square error. The proof relies on a rescaled version of De Bruijn identity for gamma target distribution together with a stochastic representation for the gamma-specific Fisher information. Finally, we are able to derive precise bounds and asymptotics for the input-output mutual information of the non-linear channel with gamma inputs.
Autors: Benjamin Arras;Yvik Swan;
Appeared in: IEEE Transactions on Information Theory
Publication date: Feb 2018, volume: 64, issue:2, pages: 1083 - 1091
Publisher: IEEE
 
» IT Professional Enters its 20th Year with Confidence
Abstract:
Incoming editor in chief Irena Bojanova presents an overview of IT Pro’s current state and where the magazine is headed.
Autors: Irena Bojanova;
Appeared in: IT Professional
Publication date: Feb 2018, volume: 20, issue:1, pages: 5 - 8
Publisher: IEEE
 
» Iterative Demodulation and Decoding Algorithm for 3GPP/LTE-A MIMO-OFDM Using Distribution Approximation
Abstract:
Soft iterative detection/decoding algorithms are fundamentally necessary for multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) adopted in the Third Generation Long Term Evolution (LTE)-Advanced in order to increase the capacity and achieve high data rates. However, their high performance critically requires log likelihood ratio computations with prohibitive complexity. This challenge will be addressed in this paper. We first use the assumption of Gaussian transmit symbols to show the equivalence among several existing algorithms. We next develop a non-Gaussian approximation for high-order constellations, which paves the way for interference cancellation-based detectors. Based on both Gaussian and non-Gaussian approximations, we thus develop several capacity-achieving iterative MIMO-OFDM demodulation and decoding algorithms. To this end, we adopt -best algorithms to take advantage of both the types of approximations and the list decoder. Unlike existing algorithms, our proposed -best algorithms make use of the a priori probabilities to generate the list. Simulations of standard-compliant LTE systems demonstrate that the proposed algorithms outperform the existing ones.
Autors: Tao Cui;Feifei Gao;Arumugam Nallanathan;Hai Lin;Chintha Tellambura;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 1331 - 1342
Publisher: IEEE
 
» Iterative Graph-Based Filtering for Image Abstraction and Stylization
Abstract:
In this brief, motivated by the recent advances in graph signal processing, we address the problem of image abstraction and stylization. A novel unified graph-based multi-layer framework is proposed to perform iterative filtering without requiring any weight updates. The proposed graph-based filtering approach is shown to be superior to other existing methods due to iteratively using the filtered Laplacian in order to enhance the smoothened image signal at each layer. In order to render real images into painterly style ones and create a simple stylized format from color images, the low-contrast regions of an image are first smoothened using the proposed iterative graph filters in either vertex or spectral domains. The abstracted image is then quantized and sharpened using the proposed iterative highpass graph filter. The effectiveness of the graph-based image stylization method is verified through several experiments. It is shown that the proposed method can yield significantly improved visual quality for stylized images as compared to other existing methods.
Autors: Hamidreza Sadreazami;Amir Asif;Arash Mohammadi;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Feb 2018, volume: 65, issue:2, pages: 251 - 255
Publisher: IEEE
 
» iTune: Engineering the Performance of Xen Hypervisor via Autonomous and Dynamic Scheduler Reconfiguration
Abstract:
Despite the widespread use of server virtualization technologies in cloud data centers, system administrators experience multiple challenges in configuring the hypervisor’s scheduler parameters to optimize its performance. Manually tuning the scheduler’s parameters is a common practice, however, this approach is not effective particularly when dealing with dynamically changing workload and resource utilizations on the host machines. This problem becomes even harder if cloud resources are overbooked while hosting both latency-sensitive and batched applications. To address these issues, this paper presents iTune, which is a framework for engineering the performance of a hypervisor intelligently via autonomous scheduler configurations. Concretely, iTune optimizes the Xen hypervisor’s scheduler configuration parameters autonomously through a three phase process comprising: (1) Discoverer, which monitors and saves the resource usage history of the host machines and groups set of related host machine workloads, (2) Optimizer, where optimum Xen scheduler configuration parameters for each workload cluster are explored by employing a simulated annealing machine learning algorithm, and (3) Observer, where iTune monitors the resource usage of host machines online, classifies them into one of the categories found in the Discoverer phase, and loads the optimum scheduler parameters determined in the Optimizer phase. Experimental results validate our claims.
Autors: Faruk Caglar;Shashank Shekhar;Aniruddha S. Gokhale;
Appeared in: IEEE Transactions on Services Computing
Publication date: Feb 2018, volume: 11, issue:1, pages: 103 - 116
Publisher: IEEE
 
» JFETIDG: A Compact Model for Independent Dual-Gate JFETs With Junction or MOS Gates
Abstract:
This paper presents the details of JFETIDG, a compact model for independent dual-gate junction field-effect transistors with any combination of p-n junction or MOS gates. JFETIDG accounts for nonlinearity from depletion pinching, velocity saturation, and self-heating, and includes extensive modeling of geometry and temperature dependences, parasitics, noise, and statistical variations. We also demonstrate that it accurately models long channel junctionless MOS transistors. The model is verified by comparison with TCAD simulations and experimental data. Verilog-A code for JFETIDG is available in the public domain.
Autors: Kejun Xia;Colin C. McAndrew;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 747 - 755
Publisher: IEEE
 
» Joint 2-D DOA and TOA Estimation for Multipath OFDM Signals Based on Three Antennas
Abstract:
A method for estimating the 2-D direction- and time-of-arrival of orthogonal frequency division multiplexing (OFDM) signals that utilizes only three antennas is proposed. An array manifold matrix is first constructed not only based on the symmetry of circular geometry but also the time diversity of every OFDM subcarrier, so that the array aperture can be greatly increased. A virtual spatial smoothing method is then used to partition the array manifold matrix into structurally identical sub-array manifold matrix, so that coherent multipaths can be correctly estimated by incorporating the eigenstructure-based techniques on the average of the sub-array covariance matrices. Simulation results are provided to demonstrate the effectiveness of the proposed method.
Autors: Longliang Chen;Wangdong Qi;En Yuan;Yuexin Zhao;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 324 - 327
Publisher: IEEE
 
» Joint Admission Control and Resource Allocation in Edge Computing for Internet of Things
Abstract:
The IoT is a novel platform for making objects more intelligent by connecting to the Internet. However, mass connections, big data processing, and huge power consumption restrict the development of IoT. In order to address these challenges, this article proposes a novel ECIoT architecture. To further enhance the system performance, radio resource and computational resource management in ECIoT are also investigated. According to the characteristics of the ECIoT, we mainly focus on admission control, computational resource allocation, and power control. To improve the performance of ECIoT, cross-layer dynamic stochastic network optimization is studied to maximize the system utility, based on the Lyapunov stochastic optimization approach. Evaluation results are provided which demonstrate that the proposed resource allocation scheme can improve throughput, reduce end-to-end delay, and also achieve an average throughput and delay trade-off. Finally, the future research topics of resource management in ECIoT are discussed.
Autors: Shichao Li;Ning Zhang;Siyu Lin;Linghe Kong;Ajay Katangur;Muhammad Khurram Khan;Minming Ni;Gang Zhu;
Appeared in: IEEE Network
Publication date: Feb 2018, volume: 32, issue:1, pages: 72 - 79
Publisher: IEEE
 
» Joint Altitude and Beamwidth Optimization for UAV-Enabled Multiuser Communications
Abstract:
We study multiuser communication systems enabled by an unmanned aerial vehicle (UAV) that is equipped with a directional antenna of adjustable beamwidth. We propose a fly-hover-and-communicate protocol, where the ground terminals are partitioned into disjoint clusters that are sequentially served by the UAV as it hovers above the corresponding cluster centers. We jointly optimize the UAV’s flying altitude and antenna beamwidth for throughput optimization in three fundamental multiuser communication models, namely, UAV-enabled downlink multicasting, downlink broadcasting, and uplink multiple access. Results show that the optimal UAV altitude and antenna beamwidth critically depend on the communication model considered.
Autors: Haiyun He;Shuowen Zhang;Yong Zeng;Rui Zhang;
Appeared in: IEEE Communications Letters
Publication date: Feb 2018, volume: 22, issue:2, pages: 344 - 347
Publisher: IEEE
 
» Joint Dynamic Rate Control and Transmission Scheduling for Scalable Video Multirate Multicast Over Wireless Networks
Abstract:
In this paper we consider the time-varying characteristics of practical wireless networks and propose a joint dynamic rate allocation and transmission scheduling optimization scheme for scalable video multirate multicast based on opportunistic routing (OR) and network coding. With OR the decision of optimal routes for scalable video coding layered streaming is integrated into the joint optimization formulation. The network throughput is also increased by taking advantage of the broadcast nature of the wireless shared medium and by network coding operations in intermediate nodes. To maximize the overall video reception quality among all destinations the proposed scheme can jointly optimize the video reception rate the associated routes to different destinations and the time fraction scheduling of transmitter sets that are concurrently transmitting in the shared wireless medium. By using dual decomposition and primal-dual update approach we develop a cross-layer algorithm in a fully distributed manner. Simulation results demonstrate significant network multicast throughput improvement and adaptation to dynamic network changes relative to existing optimization schemes.
Autors: Chenglin Li;Hongkai Xiong;Junni Zou;Dapeng Oliver Wu;
Appeared in: IEEE Transactions on Multimedia
Publication date: Feb 2018, volume: 20, issue:2, pages: 361 - 378
Publisher: IEEE
 

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