Electrical and Electronics Engineering publications abstract of: 09-2017 sorted by title, page: 5

» Circular Patch Sensor Based on Distributed Fiber Optic Technology for Tensile and Bending Loads Identification
Abstract:
The design, manufacturing, and preliminary testing of a smart patch sensor named MonitoRing are herein presented. The sensor is conceived to identify amplitude and direction of structural loads by distributed strain profile detection along its circular geometry. The sensor is manufactured by using flexible glass/epoxy laminates hosting a single standard telecom fiber optic. The fiber optic is embedded according to three loops, different by radius and quote. The sensor is then externally bonded on a structural element and able to follow the deformations under tensile and bending loading condition. The optical Rayleigh backscattering technology provides an interrogation of strain with high spatial resolution all along the fiber path. The load and direction identification is hence, provided by comparing amplitude, phase and sign of deformation spectrum of each loop. Preliminary numerical and experimental result, are reported and analyzed for simple test cases.
Autors: Monica Ciminello;Paolo Bettini;Salvatore Ameduri;Antonio Concilio;
Appeared in: IEEE Sensors Journal
Publication date: Sep 2017, volume: 17, issue:18, pages: 5908 - 5914
Publisher: IEEE
 
» Classification of Error Correcting Codes and Estimation of Interleaver Parameters in a Noisy Transmission Environment
Abstract:
Channel encoder, which includes a forward error correcting (FEC) code followed by an interleaver, plays a vital role in improving the error performance of digital storage and communication systems. In most of the applications, the FEC code and interleaver parameters are known at the receiver to decode and de-interleave the information bits, respectively. But the blind/semi-blind estimation of code and interleaver parameters at the receiver will provide additional advantages in applications, such as adaptive modulation and coding, cognitive radio, non-cooperative systems, etc. The algorithms for the blind estimation of code parameters at the receiver had previously been proposed and investigated for known FEC codes. In this paper, we propose algorithms for the joint recognition of the type of FEC codes and interleaver parameters without knowing any information about the channel encoder. The proposed algorithm classify the incoming data symbols among block coded, convolutional coded, and uncoded symbols. Further, we suggest analytical and histogram approaches for setting the threshold value to perform code classification and parameter estimation. It is observed from the simulation results that the code classification and interleaver parameter estimation are performed successfully over erroneous channel conditions. The proposed histogram approach is more robust against the analytical approach for noisy transmission environment and system latency is one of the important challenges for the histogram approach to achieve better performance.
Autors: R. Swaminathan;A. S. Madhukumar;
Appeared in: IEEE Transactions on Broadcasting
Publication date: Sep 2017, volume: 63, issue:3, pages: 463 - 478
Publisher: IEEE
 
» Classification of User Trajectories in LTE HetNets Using Unsupervised Shapelets and Multiresolution Wavelet Decomposition
Abstract:
The classification of user trajectories in Long-Term Evolution (LTE) heterogeneous networks (HetNets) is investigated in this paper. We propose a methodology to classify user trajectories based on the measurement reports submitted to the serving base station as part of the handover process; we propose to consider each measurement report as a time series. This methodology allows base stations to automatically and autonomously discover the radio-frequency (RF) conditions of their cell edge (e.g., signal strength degradation and interference levels). We propose the application of machine learning and data mining techniques to identify patterns in the reference signal received power measurement reports submitted by users as they approach the edge of the service area. Our time-series clustering algorithm based on unsupervised shapelets and multiresolution wavelet decomposition provided superior performance compared to a discrete Fourier transform (DFT)-based clustering algorithm. Our algorithm was able to provide clustering results with an average accuracy of 95%. Furthermore, the quality measure of the resulting clusters was up to 75% better, compared to the clustering results provided by the DFT-based algorithm. We also proposed a novel methodology to calculate a suitable number of clusters with no prior knowledge regarding the data; an average accuracy close to 90% was achieved.
Autors: Diego Castro-Hernandez;Raman Paranjape;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Sep 2017, volume: 66, issue:9, pages: 7934 - 7946
Publisher: IEEE
 
» Clock Data Compensation Aware Digital Circuits Design for Voltage Margin Reduction
Abstract:
Tolerating timing error due to power supply noise (PSN) in digital circuits can be done with adding voltage margins. Conservative addition of voltage margins leads wastes of power reducing the battery life in Internet of Things (IoT) devices. This paper aims to provide guidelines to avoid over-design due to PSN especially for the low-cost IoT devices. To this end, we first present an accurate time-domain behavioral model of timing slack variation due to PSN accounting for the clock-data compensation. The accuracy of the model is verified against SPICE for complex designs, including AES engine and LEON3 processor. To prove the effectiveness of our model for reducing voltage margin, we utilize our model in standard VLSI design flow for various examples, such as timing slack versus noise frequency analysis, determining optimal value of an on-die capacitor, analyzing the effects of time borrowing technique, and PVT variation simulations. The analysis shows that the model helps reduce pessimism in estimated timing slack.
Autors: Taesik Na;Jong Hwan Ko;Saibal Mukhopadhyay;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Sep 2017, volume: 64, issue:9, pages: 2401 - 2413
Publisher: IEEE
 
» Cluster Head Enhanced Election Type-2 Fuzzy Algorithm for Wireless Sensor Networks
Abstract:
This approach presents a fully distributed clustering solution for wireless sensor networks. It relies on the results of an interval type-2 fuzzy logic system that gives each node the chance to be a cluster head. Taking into account the limited computational resources of the sensors, this inference system has been carefully adapted to be run in each node through a sampling process of the entire solution space of the fuzzy system. The input variables of the system are obtained from the information that each node derives from its performance metrics and those related to its neighbors. The acquisition of these last data does not incur in any additional control packets. The results obtained show a significant improvement in the network lifetime when compared with other recent approaches. This improvement takes place even when contrasting with centralized methods.
Autors: J. C. Cuevas-Martinez;A. J. Yuste-Delgado;A. Triviño-Cabrera;
Appeared in: IEEE Communications Letters
Publication date: Sep 2017, volume: 21, issue:9, pages: 2069 - 2072
Publisher: IEEE
 
» Clustering with Hypergraphs: The Case for Large Hyperedges
Abstract:
The extension of conventional clustering to hypergraph clustering, which involves higher order similarities instead of pairwise similarities, is increasingly gaining attention in computer vision. This is due to the fact that many clustering problems require an affinity measure that must involve a subset of data of size more than two. In the context of hypergraph clustering, the calculation of such higher order similarities on data subsets gives rise to hyperedges. Almost all previous work on hypergraph clustering in computer vision, however, has considered the smallest possible hyperedge size, due to a lack of study into the potential benefits of large hyperedges and effective algorithms to generate them. In this paper, we show that large hyperedges are better from both a theoretical and an empirical standpoint. We then propose a novel guided sampling strategy for large hyperedges, based on the concept of random cluster models. Our method can generate large pure hyperedges that significantly improve grouping accuracy without exponential increases in sampling costs. We demonstrate the efficacy of our technique on various higher-order grouping problems. In particular, we show that our approach improves the accuracy and efficiency of motion segmentation from dense, long-term, trajectories.
Autors: Pulak Purkait;Tat-Jun Chin;Alireza Sadri;David Suter;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Sep 2017, volume: 39, issue:9, pages: 1697 - 1711
Publisher: IEEE
 
» CMOS Compatible Electrostatically Formed Nanowire Transistor for Efficient Sensing of Temperature
Abstract:
A novel electrostatically formed nano-wire (EFN) transistor for temperature sensing is presented. The device is a silicon-on-insulator multigate field-effect transistor, in which a nanowire-shaped conducting channel vertical position and area are controlled by the bias applied to the back gate, and two junction-side gates. Our measurements depict temperature sensitivity of 7.7%/K for EFN transistors which is among the best reported values for semiconductor temperature sensing devices TMOS and FET’s. Optimal operational voltage biases and currents for the EFN transistor regimes are evaluated from measurements and analyzed using three dimensional (3D) electrostatic device simulations and developed analytical model.
Autors: Klimentiy Shimanovich;Tom Coen;Yonatan Vaknin;Alex Henning;Joseph Hayon;Yakov Roizin;Yossi Rosenwaks;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3836 - 3840
Publisher: IEEE
 
» Coastal Sea Ice Detection Using Ground-Based GNSS-R
Abstract:
Determination of sea ice extent is important both for climate modeling and transportation planning. Detection and monitoring of ice are often done by synthetic aperture radar imagery, but mostly without any ground truth. For the latter purpose, robust and continuously operating sensors are required. We demonstrate that signals recorded by ground-based Global Navigation Satellite System (GNSS) receivers can detect coastal ice coverage on nearby water surfaces. Beside a description of the retrieval approach, we discuss why GNSS reflectometry is sensitive to the presence of sea ice. It is shown that during winter seasons with freezing periods, the GNSS-R analysis of data recorded with a coastal GNSS installation clearly shows the occurrence of ice in the bay where this installation is located. Thus, coastal GNSS installations could be promising sources of ground truth for sea ice extent measurements.
Autors: Joakim Strandberg;Thomas Hobiger;Rüdiger Haas;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Sep 2017, volume: 14, issue:9, pages: 1552 - 1556
Publisher: IEEE
 
» Cognition-Enabled Robot Manipulation in Human Environments: Requirements, Recent Work, and Open Problems
Abstract:
Service robots are expected to play an important role in our daily lives as our companions in home and work environments in the near future. An important requirement for fulfilling this expectation is to equip robots with skills to perform everyday manipulation tasks, the success of which is crucial for most home chores, such as cooking, cleaning, and shopping. Robots have been used successfully for manipulation tasks in wellstructured and controlled factory environments for decades. Designing skills for robots working in uncontrolled human environments raises many potential challenges in various subdisciplines, such as computer vision, automated planning, and human-robot interaction. In spite of the recent progress in these fields, there are still challenges to tackle. This article outlines problems in different research areas related to mobile manipulation from the cognitive perspective, reviews recently published works and the state-of-the-art approaches to address these problems, and discusses open problems to be solved to realize robot assistants that can be used in manipulation tasks in unstructured human environments.
Autors: Mustafa Ersen;Erhan Oztop;Sanem Sariel;
Appeared in: IEEE Robotics & Automation Magazine
Publication date: Sep 2017, volume: 24, issue:3, pages: 108 - 122
Publisher: IEEE
 
» Cognitively Adjusting Imprecise User Preferences for Service Selection
Abstract:
Most state-of-the-art service selection approaches assume user preferences can be provided by the target user with sufficient precision and ignore historical service usage data for all users. It is desirable for ordinary users to possess a new service selection approach that can recommend satisfactory services to them even when their service selection preferences are specified imprecisely in terms of vagueness, inaccuracy, and incompleteness. This paper proposes a novel service selection approach that resolves the imprecise characteristics of user preferences and can recommend satisfactory services for users with varying cognitive levels in terms of service experience. The proposed service selection approach is comprised of four major tasks: 1) employ user-friendly linguistic variables to collect apparent user preferences (AUP) and convert the linguistic variables to standardized fuzzy weights as AUP weights; 2) evaluate all users’ respective cognitive levels for the target service type and obtain the cognitive level threshold for that type of services; 3) adjust the AUP weights based on the calculated cognitive levels and the threshold, and supplement the potential user preferences weights; and 4) prioritize candidate services per a user satisfaction maximization objective. In-depth comparative experimental evaluations were performed using two real-world datasets. The results show that our service selection model outperforms three other representative ones and could provide a stable and reliable selection of services for the users with low service cognitive levels.
Autors: Lingyan Zhang;Shangguang Wang;Raymond K. Wong;Fangchun Yang;Rong N. Chang;
Appeared in: IEEE Transactions on Network and Service Management
Publication date: Sep 2017, volume: 14, issue:3, pages: 717 - 729
Publisher: IEEE
 
» Collaborators & Friends: The General Meeting Brings Us Together [Leader's Corner]
Abstract:
Presents highlights of the PES society 2017 General Meeting.
Autors: Jessica Bian;
Appeared in: IEEE Power and Energy Magazine
Publication date: Sep 2017, volume: 15, issue:5, pages: 10 - 10
Publisher: IEEE
 
» Comb-Assisted Cyclostationary Analysis of Wideband RF Signals
Abstract:
Signals arising in nearly all disciplines, including telecommunications, mechanics, biology, astronomy, and nature are generally modulated, carrying corresponding signatures in both the temporal and spectral domains. This fact was long recognized by cyclostationary and cumulant analysis, providing qualitatively better means to separate stochastic from deterministically modulated radiation. In contrast to simple spectral analysis, the cyclostationary technique provides a high level of spectral discrimination, allowing for considerable signal selectivity even in the presence of high levels of background noise and interference. When performed with sufficient resolution, cyclostationary analysis also provides the ability for signal analysis and classification. Unfortunately, these advantages come at a cost of large computational complexity posing fundamental detection challenges. In the case of modern ultrawideband signals, the requirements for persistent cyclostationary analysis are considerably beyond the processing complexity of conventional electronics. Recognizing this limit, we report a new photonically assisted cyclostationary analyzer that eliminates the need for high-bandwidth digitization and real-time Fourier processors. The new receiver relies on mutually coherent frequency combs used to generate a Fourier representation of the received signal in a computation-free manner. With the advent of practical, cavity-free optical frequency combs, the complexity for cyclostationary analysis can be greatly reduced, paving a path toward persistent wideband cyclostationary analysis in an ultrawideband operating regime.
Autors: Daniel J. Esman;Vahid Ataie;Bill Ping-Piu Kuo;Eduardo Temprana;Nikola Alic;Stojan Radic;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:17, pages: 3705 - 3712
Publisher: IEEE
 
» Combined Active and Reactive Power Control of Wind Farms Based on Model Predictive Control
Abstract:
This paper proposes a combined wind farm controller based on Model Predictive Control (MPC). Compared with the conventional decoupled active and reactive power controls, the proposed control scheme considers the significant impact of active power on voltage variations due to the low ratio of wind farm collector systems. The voltage control is improved. Besides, by coordination of active and reactive powers, the Var capacity is optimized to prevent potential failures due to Var shortage, especially when the wind farm operates close to its full load. An analytical method is used to calculate the sensitivity coefficients to improve the computation efficiency and overcome the convergence problem. Two control modes are designed for both normal and emergency conditions. A wind farm with 20 wind turbines was used to verify the proposed combined control scheme.
Autors: Haoran Zhao;Qiuwei Wu;Jianhui Wang;Zhaoxi Liu;Mohammad Shahidehpour;Yusheng Xue;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 1177 - 1187
Publisher: IEEE
 
» Combined Current Sensing Method for the Three-Phase Quasi-Z-Source Inverter
Abstract:
The impedance-source network converter, utilizing a unique LC network and previously forbidden shoot-through states, provides the ability to buck and boost the input voltage in a single stage. However, the inrush shoot-through current (STC) in startup or transient process might cause undesired current stresses on converter devices. This paper focuses on the STC sensing for an effective inrush current limitation by the combined current sensing technique in the quasi-Z-source inverter. STC and phase currents for the inverter control strategy are obtained simultaneously. No extra hardware is needed and the effects of current sensor bandwidth and duty cycle on the sensing accuracy are analyzed mathematically. The voltage spike gets avoided by integrating the stray inductance into the impedance network. Finally, an STC control loop based on proposed method are embedded in the field-oriented control strategy. The inrush STC and the device current stress in the transient process get suppressed. Simulation and experimental results from a quasi-Z-source inverter validate the feasibility of the proposed methods.
Autors: Sideng Hu;Zipeng Liang;Xiangning He;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7152 - 7160
Publisher: IEEE
 
» Combined Redundancy Allocation and Maintenance Planning Using a Two-Stage Stochastic Programming Model for Multiple Component Systems
Abstract:
A new modeling approach is presented to optimally and simultaneously design the configuration of a multicomponent system and determine a maintenance plan with uncertain future stress exposure. Traditionally, analytical models for system design and maintenance planning are applied sequentially, but this new model provides an integrated approach to make decisions considering the lifecycle cost of the system. Specifically considering the influence of uncertain future usage stresses on component and system reliability, the integrated redundancy allocation and maintenance planning problem is formulated as a two-stage stochastic programming model with recourse. In this model, the system is exposed to uncertain usage scenarios with their associated probabilities of occurrence or likelihood. The decision variables for the first stage are the selection of component types and the number of components to be used in the system, and these variables are modeled before the uncertainty is revealed. The second-stage variables, involving a recourse function, are the preventive maintenance plan, which defines optimal maintenance times for planned replacement of components under distinct usage scenarios. Numerical examples and sensitivity analysis on series–parallel systems demonstrate applications of the proposed model and provide further insights. The comparisons of the proposed integrated approach to traditional sequential method show advantages of the proposed model in cost saving.
Autors: Xiaoqiang Bei;Nida Chatwattanasiri;David W. Coit;Xiaoyan Zhu;
Appeared in: IEEE Transactions on Reliability
Publication date: Sep 2017, volume: 66, issue:3, pages: 950 - 962
Publisher: IEEE
 
» Combining Improved Gray-Level Co-Occurrence Matrix With High Density Grid for Myoelectric Control Robustness to Electrode Shift
Abstract:
Pattern recognition-based myoelectric control is greatly influenced by electrode shift, which is inevitable during prosthesis donning and doffing. This study used gray-level co-occurrence matrix (GLCM) to represent the spatial distribution among high density (HD) electrodes and improved its calculation based on the using condition of myoelectric system, proposing a new feature, iGLCM, to improve the robustness of the system. The effects of its two parameters, quantization level and input data, were first evaluated and it was found that improved discrete Fourier transform (iDFT) performed better than the other three (time-domain, autoregressive, root mean square) as the input data of iGLCM, and increasing quantization level did not significantly decrease the error rate of iGLCM when it was above 8. The performance of iGLCM with iDFT as input data and 8 as quantization level was subsequently compared with previous robust approaches (time domain autoregressive, variogram, common spatial pattern and optimal less channel configuration) and its input data, iDFT. It was showed that iGLCM achieved comparable classification accuracy without shift, and significantly decreased the sensitivity to electrode shift with 1 cm (p < 0.05). More importantly, it could reduce the perpendicular shift distance to half interelectrode distance with the electrodes worn as a band around the circumference of the forearm. Combined with the small interelectrode distance of HD electrodes, it provided a way to control the effect of perpendicular shifts fundamentally, which were the main source of performance degradation. Finally, the analysis of feature space revealed that the robustness was improved by discarding information sensitivity to shift and keeping as much as useful information. This study highlighted the importance of HD electrodes in robust myoelectric control, and the outcome would help the design of robust control system based on pattern recognition and promote it- application in real-world condition.
Autors: Jiayuan He;Xiangyang Zhu;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Sep 2017, volume: 25, issue:9, pages: 1539 - 1548
Publisher: IEEE
 
» Combustion Diagnostics by Calibrated Radiation Sensing and Spectral Estimation
Abstract:
Optimization of combustion processes holds the promise of maximizing energy efficiency, at the same time lowering fuel consumption and residual gases emissions. In this context, the current common operation setting in combustion processes could be improved by the introduction of passive optical sensors, which can be located close the flame, thus eliminating the inherent transport delay in current setups that only infer the combustion quality by measuring residual gases emissions. However, there is a tradeoff for flame detection between spatial-spectral resolutions, depending on the optical sensor scheme. In this paper, we present the fundamentals to avoid this constraint, obtaining a combined high spectral and spatial resolution measurement suitable for combustion diagnostics and control. The core of this proposal is to use the flame images from a low-spectral resolution charge-coupled device camera, combined with a spectral recovery method. This method is based on the off-line samples measured on the continuous component of flame spectra, providing a set of vector basis to estimate a calibrated flame spectra at each pixel. The results of the spectral recovery process verify the suitability of the method in terms of goodness-of-fit coefficient and root mean square error metrics, enabling hyper-spectral measurements based on the combination of different optical sensors. Then, continuous estimated spectra along the flame are used to calculate the energy transfer released by radiation, useful for combustion diagnostics.
Autors: Hugo O. Garcés;Luis E. Arias;Alejandro J. Rojas;Juan Cuevas;Andrés Fuentes;
Appeared in: IEEE Sensors Journal
Publication date: Sep 2017, volume: 17, issue:18, pages: 5871 - 5879
Publisher: IEEE
 
» Comment on “Optimal Precoding for a QoS Optimization Problem in Two-User MISO-NOMA Downlink”
Abstract:
Recently, optimum non-orthogonal multiple access (NOMA) precoding for a two-user multiple-input single-output (MISO) downlink has been proposed by Chen et al. Reference [1, Proposition 1] demonstrates that strong duality holds for the MISO-NOMA precoding optimization problem. Hence, the proposed preocoding algorithm is not only locally optimal, but also globally optimal. However, the proof of this proposition is flawed. In this regard, we provide a corrected proof in this comment.
Autors: Zhiyong Chen;Zhiguo Ding;Peng Xu;Xuchu Dai;Jie Xu;Derrick Wing Kwan Ng;
Appeared in: IEEE Communications Letters
Publication date: Sep 2017, volume: 21, issue:9, pages: 2109 - 2111
Publisher: IEEE
 
» Comments on “Impact of Load Frequency Dependence on the NDZ and Performance of the SFS Islanding Detection Method”
Abstract:
We read with interest an article by Zeineldin and Salama, published in the IEEE Transactions on Industrial Electronics (vol. 58, no. 1, pp. 139–146, Jan. 2011) and tried to reproduce the results of this article for the needs of our own research. Unfortunately, we were led to think that the load model equations used by the authors contained an inconspicuous but significant mathematical error, leading to erroneous results and conclusion. This letter brings corrections to some figures and their analysis as well as the paper conclusion. The new results show that the load's frequency dependence has actually no significant impact on the NDZ of the SFS method.
Autors: Olivier Arguence;Bertrand Raison;Florent Cadoux;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7277 - 7279
Publisher: IEEE
 
» Comments on “Miniaturization of a 90° Hybrid Coupler With Improved Bandwidth Performance”
Abstract:
In the above paper [1], the authors proposed a quadrature phase difference equal power division-coupled line coupler. However, the design equations presented in [1, eq. (8)] seem to be erroneous, and the bound of electrical lengths is incorrect. Here, a correct set of design equations and electrical length bound have been provided based on [2, eq. (89)].
Autors: Rakesh Sinha;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Sep 2017, volume: 27, issue:9, pages: 857 - 858
Publisher: IEEE
 
» Commercial Off-the-Shelf Digital Cameras on Unmanned Aerial Vehicles for Multitemporal Monitoring of Vegetation Reflectance and NDVI
Abstract:
This paper demonstrates the ability to generate quantitative remote sensing products by means of an unmanned aerial vehicle (UAV) equipped with one unaltered and one near infrared-modified commercial off-the-shelf (COTS) camera. Radiometrically calibrated orthomosaics were generated for 17 dates, from which digital numbers were corrected to surface reflectance and to normalized difference vegetation index (NDVI). Validation against ground measurements showed that 84%–90% of the variation in the ground reflectance and 95%–96% of the variation in the ground NDVI could be explained by the UAV-retrieved reflectance and NDVI, respectively. Comparisons against Landsat 8 data showed relationships of for reflectance and for NDVI. It was not possible to generate a fully consistent time series of reflectance, due to variable illumination conditions during acquisition on some dates. However, the calculation of NDVI resulted in a more stable UAV time series, which was consistent with a Landsat series of NDVI extracted over a deciduous and evergreen woodland. The results confirm that COTS cameras, following calibration, can yield accurate reflectance estimates (under stable within-flight illumination conditions), and that consistent NDVI time series can be acquired in very variable illumination conditions. Such methods have significant potential in providing flexible, low-cost approaches to vegetation monitoring at fine spatial resolution and for user-controlled revisit periods.
Autors: Elias F. Berra;Rachel Gaulton;Stuart Barr;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Sep 2017, volume: 55, issue:9, pages: 4878 - 4886
Publisher: IEEE
 
» Common-Mode EMI Noise Modeling and Reduction With Balance Technique for Three-Level Neutral Point Clamped Topology
Abstract:
This paper develops a common-mode (CM) electromagnetic interference noise model for a three-level neutral point clamped topology. Compared with existing modeling techniques with only one CM noise source, two extra important CM noise sources and their characteristics are identified and derived for an accurate CM noise model. The impedances of CM noise path are also extracted. Based on the developed CM noise model, the CM noise spectrum can be well predicted. The effect of CM noise paths on CM noise is discussed based on two different LCL filters. A CM noise reduction technique with a balance bridge at a large impedance ratio is proposed based on the developed model. The technique can be easily implemented at low cost. Both simulations and experiments validate the developed theory and technique.
Autors: Huan Zhang;Le Yang;Shuo Wang;Joonas Puukko;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7563 - 7573
Publisher: IEEE
 
» Communicating With Employees: Resisting the Stereotypes of Generational Cohorts in the Workplace
Abstract:
Introduction: Stereotypes about generational cohorts have been spread widely among current literature; this study challenges those stereotypes and provides a simple method for managers to learn how to effectively communicate with, motivate, and retain employees, no matter what cohort they belong to. Research questions: (1) Do people in a particular generational cohort behave according to the stereotypes assigned to their cohort? (2) Do people in a particular generation believe that the stereotypes assigned to their generation are accurate? Literature review: Current literature promulgates generational stereotypes and encourages managers to learn about the differences of each cohort so that they can tailor their communication to each cohort. Knowing the differences allegedly provides managers of technical communication teams or any team with more effective strategies to communicate with, motivate, and retain members of each cohort. Much of the literature examined was not based on rigorous research, and some that was rigorous and empirical claims there are more similarities than differences among the cohorts. Methodology: The findings from this study are based on answers to surveys from 107 participants and semistructured interviews with eight of those participants who were employees at a software company or were students or employees at a local university. The findings challenge the stereotypes found in the current literature, specifically concerning longevity in a job and workplace compliance. Conclusions, limitations, and future research: Managers need to learn more about individual employees rather than relying on stereotypes of generational cohorts when communicating with employees. Learning about individuals is simple and can foster more effective communication, which will enhance employees' job satisfaction and engagement, and ultimately employee retention. As the research reported in this study shows, these are crucial variables to consider about- a person's tenure in a position and workplace compliance behavior but are not included by most when studying generational cohorts. Further research could help us learn how managers can best develop employees and recognize and reward employees' workplace achievements.
Autors: Rhonda Stanton;
Appeared in: IEEE Transactions on Professional Communication
Publication date: Sep 2017, volume: 60, issue:3, pages: 256 - 272
Publisher: IEEE
 
» Compact Bandpass Filter With High Selectivity Using Quarter-Mode Substrate Integrated Waveguide and Coplanar Waveguide
Abstract:
This letter presents a bandpass filter (BPF) based on a hybrid structure of quarter-mode substrate integrated waveguide (QMSIW) and coplanar waveguide (CPW). By incorporating two CPW resonators into two QMSIW resonators, the proposed filter obtains a high selectivity as the coupling between two CPW resonators is electric coupling, which helps to generate two transmission zeros. It also achieves compact layout as the embedded CPW resonators do not occupy extra area. In order to verify the design, a BPF with a center frequency of 8.7 GHz is fabricated and measured. The measured results show good agreement with the simulation results.
Autors: Zhaosheng He;Chang Jiang You;Supeng Leng;Xiang Li;Yong-Mao Huang;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Sep 2017, volume: 27, issue:9, pages: 809 - 811
Publisher: IEEE
 
» Compact Broadband Circularly Polarized Antenna With Parasitic Patches
Abstract:
A broadband circularly polarized (CP) antenna with compact size is proposed. The antenna is composed of a loop feeding structure which provides sequential phase, four driven patches, and four parasitic patches. The driven patches, which are capacitively coupled by the feeding loop, generate one CP mode due to the sequentially rotated structure and four parasitic patches are introduced to produce additional CP mode. By combining with the CP mode of the feeding loop, the axial ratio (AR) bandwidth is greatly broadened. An antenna prototype is fabricated to validate the simulated results. Experimental results show that the antenna achieves a broad impedance bandwidth of 19.5% from 5.13 to 6.24 GHz and a 3-dB AR bandwidth of 12.9% (5.38–6.12 GHz). In addition, the proposed antenna also has a flat gain within the operating frequency band and a compact size of at 5.5 GHz.
Autors: Kang Ding;Cheng Gao;Dexin Qu;Qin Yin;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Sep 2017, volume: 65, issue:9, pages: 4854 - 4857
Publisher: IEEE
 
» Compact Constant Weight Coding Engines for the Code-Based Cryptography
Abstract:
We present here a more memory efficient method for encoding binary information into words of prescribed length and weight. Existing solutions either require complicated float point arithmetic or additional memory overhead, making it a challenge for resource constrained computing environment. The solution we propose here solves these problems yet obtains better coding efficiency by a memory efficient approximation of the critical intermediate value in constant weight coding. For the time being, the design presented in this brief is the most compact one for any code-based encryption schemes.
Autors: Jingwei Hu;Ray C. C. Cheung;Tim Güneysu;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Sep 2017, volume: 64, issue:9, pages: 1092 - 1096
Publisher: IEEE
 
» Compact Dual-Band Dual-Polarized Interleaved Two-Beam Array With Stable Radiation Pattern Based on Filtering Elements
Abstract:
This paper presents a compact dual-band antenna array with dual polarizations and two beams for base-station applications. It consists of two subarrays operating at 3G (1710–2170 MHz) and long term evolution (2490–2690 MHz) bands. For size miniaturization, the elements of the two subarrays are interleaved with each other. The mutual coupling between the elements operating at different bands is suppressed by using filtering antennas with out-of-band radiation suppression. And the spacing between them can be decreased, resulting in array miniaturization. To obtain stable two-beam radiation patterns within the two operating bands, the beam-forming networks with little magnitude and phase imbalances are specially designed for each band. For demonstration, the proposed array is implemented. In the measurement, the array exhibits stable 10-dB beamwidth around 120° in the azimuth plane within the two entire bands. As a result, the two-beam radiation patterns satisfy the coverage requirement of 120° in the azimuth plane for base-station applications. Additionally, 16.4 dBi/15.5 dBi peak gains and around −10 dB cross levels at the junction of two beams are achieved within the two operating bands. Compared with typical industrial products, the proposed array features both compact size and stable radiation patterns. Moreover, the proposed method can easily be extended to multibeam base-station array designs.
Autors: Xiu-Yin Zhang;Di Xue;Liang-Hua Ye;Yong-Mei Pan;Yao Zhang;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Sep 2017, volume: 65, issue:9, pages: 4566 - 4575
Publisher: IEEE
 
» Compact Millimeter-Wave CMOS Wideband Three-Transmission-Zeros Bandstop Filter Using a Single Coupled-Line Unit
Abstract:
This brief presents the design and implementation of millimeter-wave ultra-wide bandstop filter (BSF) using a standard 0.18- CMOS technology. The BSF configuration consists of a single coupled-line resonator shorted at the middle, which operates as not only a resonant element but also an open stub. The BSF realizes three transmission zeros in the stopband that results in sharp skirt selectivity. The overall width of the filter is less than the width of a 50- line and occupies a compact area of , where is the guided wavelength at 60 GHz. Explicit design equations are derived analytically using lossless transmission model. A prototype wideband BSF with a 3-dB bandwidth of 110% at 60 GHz is realized on a thin-film microstrip structure. The impact of several CMOS process parameters on the designed filter is also examined.
Autors: Venkata Narayana Rao Vanukuru;Vamsi Krishna Velidi;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Sep 2017, volume: 64, issue:9, pages: 1022 - 1026
Publisher: IEEE
 
» Compact Modeling Source-to-Drain Tunneling in Sub-10-nm GAA FinFET With Industry Standard Model
Abstract:
We present a compact model for source-to-drain tunneling current in sub-10-nm gate-all-around FinFET, where tunneling current becomes nonnegligible. Wentzel–Kramers–Brillouin method with a quadratic potential energy profile is used to analytically capture the dependence on biases in the tunneling probability expression and simplify the equation. The calculated tunneling probability increases with smaller effective mass and with increasing bias. We at first use the Gaussian quadrature method to integrate Landauer’s equation for tunneling current computation without further approximations. To boost simulation speed, some approximations are made. The simplified equation shows a good accuracy and has more flexibility for compact model purpose. The model is implemented into industry standard Berkeley Short-channel IGFET Model-common multi-gate model for future technology node, and is validated by the full-band atomistic quantum transport simulation data.
Autors: Yen-Kai Lin;Juan Pablo Duarte;Pragya Kushwaha;Harshit Agarwal;Huan-Lin Chang;Angada Sachid;Sayeef Salahuddin;Chenming Hu;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3576 - 3581
Publisher: IEEE
 
» Compact Wideband Phase Shifter Using Microstrip Self-Coupled Line and Broadside-Coupled Microstrip/CPW for Multiphase Feed-Network
Abstract:
In this letter, a compact wideband phase shifter using a microstrip self-coupled line and a broadside-coupled microstrip/CPW (BCMC) structure is proposed for multiphase feed-network. With a uniform phase reference, such a phase shifter can achieve multiphase responses by adjusting instinct self- and broadside couplings for constant phase shifts within a wideband. Then, with the combination of proposed phase shifters and a microstrip Wilkinson power divider, a multiphase feed-network can be implemented. To verify the mechanisms mentioned earlier, a wideband feed-network is fabricated with measured multiphase responses (i.e., 0°, 5.625°, 11.25°, 22.5°, 45°, 90°, and 180°) and maximum insertion loss of 1.57 dB from 1.7 to 2.3 GHz.
Autors: Jie Zhou;Huizhen Jenny Qian;Xun Luo;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Sep 2017, volume: 27, issue:9, pages: 791 - 793
Publisher: IEEE
 
» Comparative Analyses of Bi-Tapered Fiber Mach–Zehnder Interferometer for Refractive Index Sensing
Abstract:
In this paper, a high sensitivity of splicing regions tapered photonic crystal fiber (PCF) Mach–Zehnder interfero- metric refractive index (RI) sensor is described and experimentally demonstrated. Compared with cascaded bi-tapered single-mode fiber (SMF) Mach–Zehnder interferometer (MZI), the splicing regions tapered PCF MZI have higher sensitivity for the reason that it can better control and excite higher order modes, and has lower energy loss than cascaded bi-tapered PCF in the process of light transmission. Experimental results indicate that the RI sensitivity of splicing regions tapered PCF MZI could be up to 240.16 nm/RIU which is almost four times of cascaded bi-tapered SMF in the RI range of 1.3333–1.3792. Meanwhile, this splicing region tapered PCF Mach–Zehnder interferometric RI sensor has the advantages of higher RI sensitivity, good linearity, simple in making, and more potential practical value in the measurement of external RI.
Autors: Qi Wang;Bo-Tao Wang;Ling-Xin Kong;Yong Zhao;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Sep 2017, volume: 66, issue:9, pages: 2483 - 2489
Publisher: IEEE
 
» Comparative Analysis of Partitioned Stator Flux Reversal PM Machine and Magnetically Geared Machine Operating in Stator-PM and Rotor-PM Modes
Abstract:
In this paper, the partitioned stator flux reversal permanent magnet (PM) (PS-FRPM) machine and the conventional magnetically geared (MG) machine operating in both stator-PM (SPM) and rotor-PM (RPM) modes are comparatively analyzed in terms of electromagnetic performance to provide design guides for an MG machine regarding an SPM- or RPM-type machine and a higher or lower gear ratio machine. It is found that an SPM-type machine is recommended since both PS-FRPM and MG machines operating in SPM modes have a higher phase back-EMF and hence torque than their RPM counterparts, respectively, as a result of a similar phase flux linkage but a higher electric frequency since the iron piece number is larger than the PM pole-pair number. Moreover, a smaller gear ratio machine is preferred from the perspective of a higher power factor and hence a lower inverter power rating, as the conventional MG machines with higher gear ratios suffer from larger flux-leakage, higher synchronous reactance and hence lower power factors, as well as higher iron losses, than the PS-FRPM machines. However, higher gear ratio machines feature lower cogging torques and torque ripples due to the smaller difference between the PM pole-pair number and iron piece number. Both prototypes of PS-FRPM machine operating in SPM mode and MG machine operating in RPM mode are built and tested to verify the finite element predicted results.
Autors: Zhongze Wu;Z. Q. Zhu;Hanlin Zhan;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 903 - 917
Publisher: IEEE
 
» Comparative Study of RESURF Si/SiC LDMOSFETs for High-Temperature Applications Using TCAD Modeling
Abstract:
This paper analyses the effect of employing an Si on semi-insulating SiC (Si/SiC) device architecture for the implementation of 600-V LDMOSFETs using junction isolation and dielectric isolation reduced surface electric field technologies for high-temperature operations up to 300 °C. Simulations are carried out for two Si/SiC transistors designed with either PN or silicon-on-insulator (SOI) and their equivalent structures employing bulk-Si or SOI substrates. Through comparisons, it is shown that the Si/SiC devices have the potential to operate with an off-state leakage current as low as the SOI device. However, the low-side resistance of the SOI LDMOSFET is smaller in value and less sensitive to temperature, outperforming both Si/SiC devices. Conversely, under high-side configurations, the Si/SiC transistors have resistances lower than that of the SOI at high substrate bias, and invariablewith substrate potential up to −200 V, which behaves similar to the bulk-Si LDMOS at 300 K. Furthermore, the thermal advantage of the Si/SiC over other structures is demonstrated by using a rectanglepower pulse setup in TechnologyComputer-Aided Design simulations.
Autors: C. W. Chan;F. Li;A. Sanchez;P. A. Mawby;P. M. Gammon;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3713 - 3718
Publisher: IEEE
 
» Comparison for 1/ ${f}$ Noise Characteristics of AlGaN/GaN FinFET and Planar MISHFET
Abstract:
DC and 1/ noise performances of the AlGaN/GaN fin-shaped field-effect transistor (FinFET) with fin width of 50 nm were analyzed. The FinFET exhibited approximately six times larger normalized drain current and transconductance, compared to those of the AlGaN/GaN planar metal-insulator-semiconductor heterostructure field-effect-transistor (MISHFET) fabricated on the same wafer. It was also observed that the FinFET exhibited improved noise performance with lower noise magnitude of /Hz when compared to the value of /Hz for the planar MISHFET. An intensive analysis indicated that both devices follow the carrier number fluctuation model, but the FinFET suffers much less charge trapping effect compared to the MISHFET (two orders lower charge trapping was observed). Moreover, the FinFET did not exhibit the Lorentz-like components, which explains that the depleted fin structure effectively prevents the carriers from being trapped into the underlying thick GaN buffer layer. On the other hand, the slope of the noise is 2 irrespective of drain voltage and apparently showed the Lorentz-like components, especially at high drain voltage in MISHFET device. This explains that the carrier trapping/detrapping between the 2-D electron gas channel and the GaN buffer layer is significant in MISHFET.
Autors: Sindhuri Vodapally;Christoforos G. Theodorou;Youngho Bae;Gérard Ghibaudo;Sorin Cristoloveanu;Ki-Sik Im;Jung-Hee Lee;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3634 - 3638
Publisher: IEEE
 
» Comparison of Canopy Cover Estimations From Airborne LiDAR, Aerial Imagery, and Satellite Imagery
Abstract:
Canopy cover is an important forest structure parameter for many applications in ecology, hydrology, and forest management. Light detection and ranging (LiDAR) is a promising tool for estimating canopy cover because it can penetrate forest canopy. Various algorithms have been developed to calculate canopy cover from LiDAR data. However, little attention was paid to evaluating how different factors, such as estimation algorithm, LiDAR point density and scan angle, influence canopy cover estimates; and how LiDAR-derived canopy cover differs from estimates using traditional methods, such as field measurements, aerial and satellite imagery. In this study, we systematically compared canopy cover estimations from LiDAR data, quick field measurements, aerial imagery, and satellite imagery using different algorithms. The results show that LiDAR-derived canopy cover estimates are marginally influenced by the estimation algorithms. LiDAR data with a point density of 1 point/m2 can generate comparable canopy cover estimates to data with a higher density. The uncertainty of canopy cover estimates from LiDAR data increased drastically as scan angles exceed 12°. Plot-level canopy cover estimates derived from quick field measurements do not have strong correlation with LiDAR-derived estimations. Both the aerial imagery-derived and satellite imagery-derived canopy cover estimates are comparable to LiDAR-derived canopy cover estimates at the forest stand scale, but tend to be overestimated in sparse forests and be underestimated in dense forests, particularly for the aerial imagery-derived estimates. The results from this study can provide practical guidance for the selection of data sources, sampling schemes, and estimation methods in regional canopy cover mapping.
Autors: Qin Ma;Yanjun Su;Qinghua Guo;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Sep 2017, volume: 10, issue:9, pages: 4225 - 4236
Publisher: IEEE
 
» Comparison of Collision-Free and Contention-Based Radio Access Protocols for the Internet of Things
Abstract:
The fifth-generation (5G) cellular networks will face the challenge of integrating the traditional broadband services with the Internet of Things (IoT), which is characterized by sporadic uplink transmissions of small data packets. Indeed, the access procedure of the previous generation cellular network (4G) is not able to support IoT traffic efficiently, because it requires a large amount of signaling for the connection setup before the actual data transmission. In this context, we introduce two innovative radio access protocols for sporadic transmissions of small data packets, which are suitable for 5G networks, because they provide a resource-efficient packet delivery exploiting a connectionless approach. The core of this paper resides in the derivation of an analytical framework to evaluate the performance of all the aforementioned protocols. The final goal is the comparison between 4G and 5G radio access solutions employing both our analytical framework and computer simulations. The performance evaluation results show the benefits of the protocols envisioned for 5G in terms of signaling overhead and access latency.
Autors: Marco Centenaro;Lorenzo Vangelista;Stephan Saur;Andreas Weber;Volker Braun;
Appeared in: IEEE Transactions on Communications
Publication date: Sep 2017, volume: 65, issue:9, pages: 3832 - 3846
Publisher: IEEE
 
» Comparison of Constant-Posture Force-Varying EMG-Force Dynamic Models About the Elbow
Abstract:
Numerous techniques have been used to minimize error in relating the surface electromyogram (EMG) to elbow joint torque. We compare the use of three techniques to further reduce error. First, most EMG-torque models only use estimates of EMG standard deviation as inputs. We studied the additional features of average waveform length, slope sign change rate and zero crossing rate. Second, multiple channels of EMG from the biceps, and separately from the triceps, have been combined to produce two low-variance model inputs. We contrasted this channel combination with using each EMG separately. Third, we previously modeled nonlinearity in the EMG-torque relationship via a polynomial. We contrasted our model versus that of the classic exponential power law of Vredenbregt and Rau (1973). Results from 65 subjects performing constant-posture, force-varying contraction gave a “baseline” comparison error (i.e., error with none of the new techniques) of 5.5 ± 2.3% maximum flexion voluntary contraction (%MVCF). Combining the techniques of multiple features with individual channels reduced error to 4.8 ± 2.2 %MVCF, while combining individual channels with the power-law model reduced error to 4.7 ± 2.0 %MVCF. The new techniques further reduced error from that of the baseline by %.
Autors: Chenyun Dai;Berj Bardizbanian;Edward A. Clancy;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Sep 2017, volume: 25, issue:9, pages: 1529 - 1538
Publisher: IEEE
 
» Comparison of High-Speed Electrical Motors for a Turbo Circulator Application
Abstract:
This paper presents an analysis of three different electrical machine topologies for a turbo circulator application. The electrical machines are designed to operate with 6 kW output power at 120 000 r/min. This paper demonstrates the design aspects of one solid rotor squirrel cage induction motor and two permanent magnet synchronous machines. The machines are compared using electromagnetic, thermal, and mechanical analyses. The benefits and disadvantages of each topology under study are discussed. For other high-speed applications presented, a comparative approach helps in selecting the suitable electrical machine topology by analyzing the performance criteria discussed. The prototype construction of one of the topologies is analyzed.
Autors: Nikita Uzhegov;Jan Barta;Jiri Kurfürst;Cestmir Ondrusek;Juha Pyrhönen;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Sep 2017, volume: 53, issue:5, pages: 4308 - 4317
Publisher: IEEE
 
» Comparison of TerraSAR-X and ALOS PALSAR Differential Interferometry With Multisource DEMs for Monitoring Ground Displacement in a Discontinuous Permafrost Region
Abstract:
Differential synthetic aperture radar interferometry (DInSAR) has shown its capability in monitoring ground displacement caused by the freeze-thaw cycle in the active layer of permafrost regions. However, the unique landscape in the discontinuous permafrost zone increases the difficulty of applying DInSAR to detect ground displacements. In this study, datasets from two radar systems, X-band TerraSAR-X and L-band ALOS PALSAR, were used to evaluate the influencing factors and application conditions for DInSAR in the discontinuous permafrost environment based on a large number of analyzed interferograms. Furthermore, the impact of different DEMs on the application of DInSAR was illustrated by comparing the high-resolution LiDAR-DEM, TanDEM-X DEM, and SRTM DEM. The results demonstrate that temporal decorrelation and strong volume decorrelation in areas with developed vegetation highly constrains the application of X-band data. In terrain with more developed vegetation (such as shrubs and spruce), the X-band differential phase becomes linked to the canopy rather than the topography, whereas L-band data show promising results in retrieving topography-related displacement. By comparing the displacement velocity maps of the two sensors and referencing in situ measurements, we demonstrated that the ALOS PALSAR results capture the permafrost-induced terrain movement characteristics and values in the correct range. Moreover, the influence of soil moisture and vegetation phenology on the accuracy of displacement retrievals using the L-band data are illustrated and discussed. The analyses confirm that the L-band has strong advantages over the X-band in monitoring displacements in discontinuous permafrost environments.
Autors: Lingxiao Wang;Philip Marzahn;Monique Bernier;Andres Jacome;Jimmy Poulin;Ralf Ludwig;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Sep 2017, volume: 10, issue:9, pages: 4074 - 4093
Publisher: IEEE
 
» Comparison of Two-Individual Current Control and Vector Space Decomposition Control for Dual Three-Phase PMSM
Abstract:
The relationship between the two-individual current control and the vector space decomposition (VSD) control for a dual three-phase permanent magnet synchronous machine (PMSM) is investigated in this paper. It is found that the VSD control is more flexible in controlling the fundamental current in subplane and the fifth, seventh current harmonics in subplane with different proportional and integral (PI) gains, while the two-individual current control is comparable with the VSD control in having the same PI gains in the and subplanes. It is also found that the two-individual current control may have potential instability issues due to the mutual coupling between the two sets of three-phase windings. If the mutual coupling between the two sets is weak to some extent, then the two-individual current control could have the same dynamic performance as the VSD control without the stability issues. Experiments are conducted on a prototype dual three-phase PMSM to validate the theoretical analysis.
Autors: Yashan Hu;Z. Q. Zhu;Milijana Odavic;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Sep 2017, volume: 53, issue:5, pages: 4483 - 4492
Publisher: IEEE
 
» Comparison of X-Band and L-Band Soil Moisture Retrievals for Land Data Assimilation
Abstract:
This paper explores for the first time assimilation of the X-band soil moisture retrievals by the advanced microwave scanning radiometer-Earth observing system and the advanced microwave scanning radiometer 2 in Environment Canada's standalone Modélisation Environmentale Surface et Hydrologie model over the Great Lakes basin, in comparison with the assimilation of L-band soil moisture retrievals from the soil moisture and ocean salinity mission. A priori rescaling on satellite retrievals is performed by matching their cumulative distribution function (CDF) to the model surface soil moisture's CDF, in order to reduce the satellite-model bias in the assimilation system. The satellite retrievals, the open-loop model soil moisture (no assimilation), and the assimilation soil moisture estimates are validated against point-scale in situ measurements, in terms of the daily-spaced anomaly time series correlation coefficient R (soil moisture skill). Results show that assimilating X-band retrievals can improve the model soil moisture skill for both surface and root zone soil layers. The assimilation of L-band retrievals results in greater soil moisture skill improvement ΔR A-M (the assimilation skill minus the skill for the open loop model) than the assimilation of X-band products does, although the sensitivity of the assimilation to the satellite retrieval capability may become progressively weaker as the open-loop skill increases. The joint assimilation of X-band and L-band retrievals does not necessarily yield the greatest skill improvement. Overall, ΔRA-M exhibits a strong dependence upon the difference between the satellite retrieval skill and the open-loop surface soil moisture skill.
Autors: Xiaoyong Xu;Bryan A. Tolson;Jonathan Li;Bruce Davison;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Sep 2017, volume: 10, issue:9, pages: 3850 - 3860
Publisher: IEEE
 
» Comparison on the Synchronization of Two Parallel GaAs Photoconductive Semiconductor Switches Excited by Laser Diodes
Abstract:
In this letter, the synchronization of GaAs photoconductive semiconductor switches in two electrically driven configurations for laser diodes excitation is investigated. Comparisons on the synchronization are carried out by varying the bias electric field and optical excitation energy. The optimum synchronization of 296 ps is achieved at 1.2 kV with optical excitation energy of . The results demonstrate the relationship between the synchronization and transient carriers’ population ratio among the intervalley.
Autors: Wei Shi;Yu Ji;Ming Xu;Cui Chen;Junjun Shi;Shaoqiang Wang;Rujun Liu;
Appeared in: IEEE Electron Device Letters
Publication date: Sep 2017, volume: 38, issue:9, pages: 1274 - 1277
Publisher: IEEE
 
» Comparison Study of Noncontact Vital Signs Detection Using a Doppler Stepped-Frequency Continuous-Wave Radar and Camera-Based Imaging Photoplethysmography
Abstract:
In this paper, we compare the performance of radar and optical (camera based) techniques in detecting vital signs such as respiratory rate (RR), heart rate (HR), and blood oxygen saturation (SpO2). Specifically, we investigate the application of ultrawideband stepped-frequency continuous-wave radar and imaging photoplethysmography (iPPG) techniques to measure vital signs. The radar performance can be enhanced by using phase information of backscattered signal instead of its amplitude. On the other hand, the iPPG system can be enhanced by using more than one camera and utilizing very selective narrowband filters coupled with good illumination. In either system, use of advanced signal processing is required to improve accuracy. Generally, HR and RR can be accurately read by either microwave radar or optical techniques with 500 lx illumination level to have < ±2% error up to 2 m distance between the subject and the system, but optical technique errors increase significantly to < ±15% for <200 lx. However, each system has its unique advantages as the radar can be used for seeing-through walls and optical technique is uniquely capable of measuring SpO2).
Autors: Lingyun Ren;Lingqin Kong;Farnaz Foroughian;Haofei Wang;Paul Theilmann;Aly E. Fathy;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3519 - 3529
Publisher: IEEE
 
» Compensation of Long-Term Memory Effects on GaN HEMT-Based Power Amplifiers
Abstract:
The long-term memory effects of gallium nitride (GaN) transistors have prevented its use in situations where the modulated envelope signal has a wide amplitude variation over time, such as in time division duplex systems. These long-term memory effects are generally attributed to electron trapping in GaN high electron-mobility transistors (HEMT), which have shown to be very difficult to compensate, especially in cellular base station transmitters known to be subjected to highly restrictive linearity specifications. On top of the electron trapping effects, we show that thermal effects can also induce long-term memory behaviors, which should also be accounted for when linearizing these devices. Because the conventional behavioral modeling approach has been incapable to compensate these long-term memory effects on GaN HEMT-based power amplifiers (PAs), we started by investigating the physical mechanisms responsible for these semiconductor impairments in GaN devices. This physics-based knowledge was then used to design new predistorter models that could effectively compensate those PAs subjected to GaN trapping and thermal effects. In this paper, we describe the new predistortion models for PA linearization, as well as the characterization methods used to determine their parameters. To validate the linearization effectiveness of the proposed model, several high power GaN-based PAs are tested with multicarrier GSM signals, and their linearization results are compared against other state-of-the-art models, evidencing a clear and significant improvement. In fact, to the authors’ knowledge, the proposed approach is the first one to reduce the PA distortion effects due to GaN long-term memory effects to such low levels, allowing a comfortable compliance with the imposed linearity masks.
Autors: Filipe M. Barradas;Luís C. Nunes;Telmo R. Cunha;Pedro M. Lavrador;Pedro M. Cabral;José C. Pedro;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3379 - 3388
Publisher: IEEE
 
» Complete Electrical Arc Hazard Classification System and Its Application
Abstract:
The standard for electrical safety in the workplace, National Fire Protection Association 70E, and relevant Occupational Safety and Health Act electrical safety standards evolved in the U.S. over the past 40 years to address the hazards of 60-Hz power that are faced primarily by electricians, linemen, and others performing facility and utility work. This leaves a substantial gap in the management of other types of electrical hazards including battery banks, dc power systems, capacitor banks, and solar power systems. Although many of these systems are fed by 50/60-Hz energy, we find substantial use of electrical energy, and the use of capacitors, inductors, batteries, solar, and radiofrequency (RF) power. The electrical hazards of these forms of electricity and their systems are different than for 50/60 Hz ac power. At the IEEE Electrical Safety Workshop in 2009, we presented a comprehensive approach to classifying the electrical shock hazards of all types of electricity, including various waveforms and various types of sources of electrical energy. That paper introduced a new comprehensive electrical shock hazard classification system that used a combination of voltage, shock current available, fault current available, power, energy, and waveform to classify all forms of electrical hazards with a focus on the shock hazard. That paper was based on research conducted over the past 100 years and on decades of experience. This paper continues the effort in understanding and managing all forms of injury from all forms of electricity with the introduction of a comprehensive approach to classifying all forms of injury from the electrical arc, including thermal, blast pressure, hearing, radiation, and shrapnel injury. The general term “arc” is divided into the arc, arc flash, and arc blast as a first subdivision of type of source of injury. Then, the parameters of voltage, short-circuit current, energy, waveform, gap distance, gap geom- try, enclosure geometry, and time are used to choose various approaches to analysis. Recent efforts to understand, model, and estimate injury for these types of systems are reviewed. Most of the focus to understand and predict injury for dc, capacitor, solar, and RF arc hazards has been only in the past 10 years. A comprehensive approach to analyzing all forms of injury from all forms of electrical arcs is presented.
Autors: Lloyd B. Gordon;Kyle D. Carr;Nicole Graham;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Sep 2017, volume: 53, issue:5, pages: 5078 - 5087
Publisher: IEEE
 
» Complex Delta–Sigma-Based Transmitter With Enhanced Linearity Performance Using Pulsed Load Modulation Power Amplifier
Abstract:
This paper proposes a linear and efficient transmitter prototype based on pulsed load modulation (PLM) power amplifier (PA). The proposed transmitter setup utilizes the complex delta–sigma (DS) modulation as a signal processing technique instead of the envelope DS modulation for higher linearity performance. Using the complex DS modulation technique reduces the in-band quantization noise significantly at the output of the modulator and consequently, enhances the linearity of the transmitter. To validate the proposed technique, the linearity and efficiency performance of the complex DS modulator (CDSM)-based transmitter are compared with the performance of its envelope DS modulator (EDSM) counterpart in measurement. For this paper, an efficient and linear PLM PA is designed and fabricated using GaAs E-pHEMT transistors. For a Long-Term Evolution (LTE) uplink standard signal with 3-MHz bandwidth and 7-dB peak-to-average power ratio, the CDSM-based transmitter achieves the drain efficiency and power added efficiency of 46% and 42%, respectively, at an average output power of 25.1 dBm. The comparison measurement study of EDSM-based transmitter and the CDSM-based transmitter with the LTE uplink signal shows about 11-dB improvement in the signal-to-noise and distortion ratio of the output signal. The measurement results for LTE signals were able to pass the spectral requirements defined by the standard without applying predistortion techniques.
Autors: Maryam Jouzdani;Mohammad Mojtaba Ebrahimi;Mohamed Helaoui;Fadhel M. Ghannouchi;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3324 - 3335
Publisher: IEEE
 
» Composability Verification of Multi-Service Workflows in a Policy-Driven Cloud Computing Environment
Abstract:
The emergence of cloud computing infrastructure and Semantic Web technologies has created unprecedented opportunities for composing large-scale business processes and workflow-based applications that span multiple organizational domains. A key challenge related to composition of such multi-organizational business processes and workflows is posed by the security and access control policies of the underlying organizational domains. In this paper, we propose a framework for verifying secure composability of distributed workflows in an autonomous multi-domain environment. The objective of workflow composability verification is to ensure that all the users or processes executing the designated workflow tasks conform to the time-dependent security policy specifications of all collaborating domains. A key aspect of such verification is to determine the time-dependent schedulability of distributed workflows, assumed to be invoked on a recurrent basis. We use a two-step approach for verifying secure workflow composability. In the first step, a distributed workflow is decomposed into domain-specific projected workflows and is verified for conformance with the respective domain's security and access control policy. In the second step, the cross-domain dependencies amongst the workflow tasks performed by different collaborating domains are verified.
Autors: Basit Shafiq;Sameera Ghayyur;Ammar Masood;Zahid Pervaiz;Abdulrahman Almutairi;Farrukh Khan;Arif Ghafoor;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Sep 2017, volume: 14, issue:5, pages: 478 - 493
Publisher: IEEE
 
» Comprehensive Capacitance–Voltage Simulation and Extraction Tool Including Quantum Effects for High- $k$ on SixGe1−x and InxGa1−xAs: Part II—Fits and Extraction From Experimental Data
Abstract:
Capacitance-voltage (–) measurement and analysis is highly useful for determining important information about MOS gate stacks. Parameters such as the equivalent oxide thickness (EOT), substrate doping density, flatband voltage, fixed oxide charge, density of interface traps (), and effective gate work function can all be extracted from experimental – curves. However, to extract these gate-stack parameters accurately, the correct models must be utilized. In Part I, we described the modeling and implementation of a – code that can be used for alternative channel semiconductors in conjunction with high- gate dielectrics and metal gates. Importantly, this new code (CV ACE) includes the effects of nonparabolic bands and quantum capacitance, enabling accurate models to be applied to experimental – curves. In this paper, we demonstrate the capabilities of this new code to extract accurate parameters, including EOT and profiles from experimental high- on Ge and In0.53<- sub>Ga0.47As gate stacks.
Autors: Sarkar R. M. Anwar;William G. Vandenberghe;Gennadi Bersuker;Dmitry Veksler;Giovanni Verzellesi;Luca Morassi;Rohit V. Galatage;Sumit Jha;Creighton Buie;Adam T. Barton;Eric M. Vogel;Christopher L. Hinkle;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3794 - 3801
Publisher: IEEE
 
» Comprehensive Capacitance–Voltage Simulation and Extraction Tool Including Quantum Effects for High-k on SixGe1−x and InxGa1−xAs: Part I—Model Description and Validation
Abstract:
High-mobility alternative channel materials to silicon are critical to the continued scaling of MOS devices. The analysis of capacitance–voltage (C–V) measurements on these new materials with high-k gate dielectrics is a critical technique to determine many important gate-stack parameters. While there are very useful C–V analysis tools available to the community, these tools are all limited in their applicability to alternative semiconductor channel MOS gate-stack analysis since they were developed for silicon. Here, we report on a new comprehensive C–V simulation and extraction tool, called CV Alternative Channel Extraction (ACE), that incorporates a wide range of semiconductors and dielectrics with the capability to implement customized gate stacks. Fermi–Dirac carrier statistics, nonparabolic bands, and quantum mechanical effects are all implemented with options to turn each of these off as the user desires. Interface state capacitance () is implemented using a common model for systems like Si and Ge. A more complex model is also implemented for III–Vs that accurately captures frequency dispersion in accumulation that arises from tunneling. CV ACE enables extremely fast simulation and extraction and can accommodate measurements performed at variable temperatures and frequencies to allow for a more accurate extraction of interface state density ().
Autors: Sarkar R. M. Anwar;William G. Vandenberghe;Gennadi Bersuker;Dmitry Veksler;Giovanni Verzellesi;Luca Morassi;Rohit V. Galatage;Sumit Jha;Creighton Buie;Adam T. Barton;Eric M. Vogel;Christopher L. Hinkle;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3786 - 3793
Publisher: IEEE
 
» Compressed Level Crossing Sampling for Ultra-Low Power IoT Devices
Abstract:
Level crossing sampling (LCS) is a power-efficient analog-to-digital conversion scheme for spikelike signals that arise in many Internet of Things-enabled automotive and environmental monitoring applications. However, LCS scheme requires a dedicated time-to-digital converter with large dynamic range specifications. In this paper, we present a compressed LCS that exploits the signal sparsity in the time domain. At the compressed sampling stage, a continuous-time ternary encoding scheme converts the amplitude variations into a ternary timing signal that is captured in a digital random sampler. At the reconstruction stage, a low-complexity split-projection least squares (SPLSs) signal reconstruction algorithm is presented. The SPLS splits random projections and utilizes a standard least squares approach that exploits the ternary-valued amplitude distribution. The SPLS algorithm is hardware friendly, can be run in parallel, and incorporates a low-cost k-term approximation scheme for matrix inversion. The SPLS hardware is analyzed, designed, and implemented in FPGA, achieving the highest data throughput and the power efficiency compared with the prior arts. Simulations of the proposed sampler in an automotive collision warning system demonstrate that the proposed compressed LCS can be very power efficient and robust to wireless interference, while achieving an approximately eightfold data volume compression when compared with Nyquist sampling approaches.
Autors: Jun Zhou;Amir Tofighi Zavareh;Robin Gupta;Liang Liu;Zhongfeng Wang;Brian M. Sadler;Jose Silva-Martinez;Sebastian Hoyos;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Sep 2017, volume: 64, issue:9, pages: 2495 - 2507
Publisher: IEEE
 
» Compressed Training Adaptive Equalization: Algorithms and Analysis
Abstract:
We propose “compressed training adaptive equalization” as a novel framework to reduce the quantity of training symbols in a communication packet. It is a semi-blind approach for communication systems employing time-domain/frequency-domain equalizers, and founded upon the idea of exploiting the magnitude boundedness of digital communication symbols. The corresponding algorithms are derived by combining the least-squares-cost-function measuring the training symbol reconstruction performance and the infinity-norm of the equalizer outputs as the cost for enforcing the special constellation boundedness property along the whole packet. In addition to providing a framework for developing effective adaptive equalization algorithms based on convex optimization, the proposed method establishes a direct link with compressed sensing by utilizing the duality of the and norms. This link enables the adaptation of recently emerged -norm-minimization-based algorithms and their analysis to the channel equalization problem. In particular, we show for noiseless/low noise scenarios, the required training length is on the order of the logarithm of the channel spread. Furthermore, we provide approximate performance analysis by invoking the recent MSE results from the sparsity-based data processing literature. Provided examples illustrate the significant training reductions by the proposed approach and demonstrate its potential for high bandwidth systems with fast mobility.
Autors: Baki B. Yilmaz;Alper T. Erdogan;
Appeared in: IEEE Transactions on Communications
Publication date: Sep 2017, volume: 65, issue:9, pages: 3907 - 3921
Publisher: IEEE
 
» Condition Codes Evaluation on Dynamic Binary Translation for Embedded Platforms
Abstract:
A widely recognized issue when implementing dynamic binary translation is the condition codes (CCs) or flag bits emulation. The authors in the literature have approached this problem with software optimization techniques based on dataflow analysis, instruction set architecture (ISA) extensions and additional dedicated hardware, i.e., field-programmable gate array. We introduce a novel technique to handle CCs using commercial off-the-shelf architectural debug hardware as a triggering mechanism while assessing and comparing it with two existent CCs evaluation methods on the resource-constrained embedded systems arena. Our method is functionality-wise comparable with reconfigurable hardware modules or ISA extensions in open architectures and is source architecture independent, with possible applications in other use scenarios, such as application debugging and instrumentation.
Autors: Filipe Salgado;Tiago Gomes;Sandro Pinto;Jorge Cabral;Adriano Tavares;
Appeared in: IEEE Embedded Systems Letters
Publication date: Sep 2017, volume: 9, issue:3, pages: 89 - 92
Publisher: IEEE
 
» Conflict-Free Loop Mapping for Coarse-Grained Reconfigurable Architecture with Multi-Bank Memory
Abstract:
Coarse-grained reconfigurable architecture (CGRA) is a promising architecture with high performance, high power-efficiency and attraction of flexibility. The computation-intensive parts of an application (e.g., loops) are often mapped on CGRA for acceleration. Due to the high parallel data access demands, the architecture with multi-bank memory is proposed to improve parallelism. For CGRA with multi-bank memory, a joint solution, which simultaneously considers the memory partitioning and modulo scheduling, is proposed to achieve a valid mapping with better performance. In this solution, the modulo scheduling and operator scheduling are used to achieve a valid loop mapping and a valid data placement without any memory access conflicts. By avoiding the pipelining stalls caused by conflicts, the performance of loop mapping is greatly improved. The experimental results on benchmarks of the Livermore, Polybench and Mediabench show that our approach can improve the performance of loops on CGRA to 1.89, 1.49 and 1.37 compared with REGIMap, HTDM and REGIMap with memory partitioning, at cost of an acceptable increase in compilation time.
Autors: Shouyi Yin;Xianqing Yao;Tianyi Lu;Dajiang Liu;Jiangyuan Gu;Leibo Liu;Shaojun Wei;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Sep 2017, volume: 28, issue:9, pages: 2471 - 2485
Publisher: IEEE
 
» Confusion-Matrix-Based Kernel Logistic Regression for Imbalanced Data Classification
Abstract:
There have been many attempts to classify imbalanced data, since this classification is critical in a wide variety of applications related to the detection of anomalies, failures, and risks. Many conventional methods, which can be categorized into sampling, cost-sensitive, or ensemble, include heuristic and task dependent processes. In order to achieve a better classification performance by formulation without heuristics and task dependence, we propose confusion-matrix-based kernel logistic regression (CM-KLOGR). Its objective function is the harmonic mean of various evaluation criteria derived from a confusion matrix, such criteria as sensitivity, positive predictive value, and others for negatives. This objective function and its optimization are consistently formulated on the framework of KLOGR, based on minimum classification error and generalized probabilistic descent (MCE/GPD) learning. Due to the merits of the harmonic mean, KLOGR, and MCE/GPD, CM-KLOGR improves the multifaceted performances in a well-balanced way. This paper presents the formulation of CM-KLOGR and its effectiveness through experiments that comparatively evaluated CM-KLOGR using benchmark imbalanced datasets.
Autors: Miho Ohsaki;Peng Wang;Kenji Matsuda;Shigeru Katagiri;Hideyuki Watanabe;Anca Ralescu;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Sep 2017, volume: 29, issue:9, pages: 1806 - 1819
Publisher: IEEE
 
» Conic Programming-Based Lagrangian Relaxation Method for DCOPF With Transmission Losses and its Zero-Gap Sufficient Condition
Abstract:
This paper presents a fast optimization approach framework for the DC optimal power flow (DCOPF) with the consideration of transmission losses, which is confronted with nonconvex quadratically constrained quadratic programming. Specifically, a second-order cone programming-based Lagrangian relaxation method is employed to obtain the lower bound of the original DCOPF. Furthermore, a sufficient condition for the zero-gap relaxation is derived, which is easy to be satisfied in practice. Finally, the comparison with existing DCOPF solvers shows that the proposed method could achieve the global optimal solution and jump out of the local optimality. Also, the comparison with the widely used semidefinite programming relaxation approach indicates that the proposed relaxation method needs less dummy variables, and thus can be more efficiently solved and more applicable for large-scale power systems.
Autors: Tao Ding;Chaoyue Zhao;Tianen Chen;Ruifeng Liu;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3852 - 3861
Publisher: IEEE
 
» Connected Vehicular Transportation: Data Analytics and Traffic-Dependent Networking
Abstract:
With onboard operating systems becoming increasingly common in vehicles, the realtime broadband infotainment and intelligent transportation system (ITS) service applications in fast-moving vehicles become ever demanding, and they are expected to significantly improve the efficiency and safety of our daily on-road lives. The emerging ITS and vehicular applications (e.g., trip planning), however, require substantial efforts in real-time pervasive information collection and big data processing to allow quick decision making and feedback to fast-moving vehicles, which imposes significant challenges on the development of an efficient vehicular communication platform. In this article, we present TrasoNET, an integrated network framework that provides real-time intelligent transportation services to connected vehicles by exploring the data analytics and networking techniques. TrasoNET is built upon two key components. The first guides vehicles to the appropriate access networks by exploring the real-time status of local traffic, specific user preferences, service applications, and network conditions. The second mainly involves a distributed automatic access engine, which enables individual vehicles to make distributed access decisions based on recommendations, local observations, and historic information. We highlight the application of TrasoNET in a case study on real-time traffic sensing based on real traces of taxis.
Autors: Cailian Chen;Tom Hao Luan;Xinping Guan;Ning Lu;Yunshu Liu;
Appeared in: IEEE Vehicular Technology Magazine
Publication date: Sep 2017, volume: 12, issue:3, pages: 42 - 54
Publisher: IEEE
 
» Connecting Things to the IoT by Using Virtual Peripherals on a Dynamically Multithreaded Cortex M3
Abstract:
The Internet of Things communicates with the world by using a wide range of different sensors and actuators. These interfaces are based on a wide range of various protocols, such as I2C, SPI, RS232, 1-wire, and so on. There are two conceptional different solutions to provide these interfaces. One is to use dedicated hardware for it. An example would be to use a peripheral on a system-on-a-chip (SoC). All SoC providers offer the families of SoC solutions with different kind of hardware peripheral combinations. The alternative concept it to run virtual peripherals as a software routine on a CPU, preferable on a multithreaded CPU. C-Slow Retiming (CSR) is a known design transformation to generate multithreaded CPUs. This paper argues, that system hyper pipelining overcomes the limitations of CSR by adding thread stalling, bypassing, and reordering techniques to better cope with the challenges of multithreading. This dynamic multithreaded environment is ideal for running virtual peripheral. The benefits of using system hyper pipelining for virtual peripherals are demonstrated on a Cortex M3-based system.
Autors: Tobias Strauch;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Sep 2017, volume: 64, issue:9, pages: 2462 - 2469
Publisher: IEEE
 
» Considering Backhaul [Book\Software Reviews]
Abstract:
This book offers a comprehensive guide to the subject of microwave backhaul. Design information on this subject is sparse, and it is not easy to collect and interpret. This fact was the driving force behind the creation of this book, which focuses on the electronics of backhaul and describes in detail all the subsystems responsible for transforming the information signal that comes from baseband processing into an electromagnetic wave traveling through the air. Electronics for Microwave Backhaul presents an overview of the evolution of the electronics for microwave radios, from their initial development to present implementations and future trends. The authors have stayed abreast of current real-world industry products and present many real-world solutions to the design issues.
Autors: James Chu;
Appeared in: IEEE Microwave Magazine
Publication date: Sep 2017, volume: 18, issue:6, pages: 125 - 126
Publisher: IEEE
 
» Constant Compositions in the Sphere Packing Bound for Classical-Quantum Channels
Abstract:
The sphere packing bound, in the form given by Shannon, Gallager, and Berlekamp, was recently extended to classical-quantum channels, and it was shown that this creates a natural setting for combining probabilistic approaches with some combinatorial ones such as the Lovász theta function. In this paper, we extend the study to the case of constant-composition codes. We first extend the sphere packing bound for classical-quantum channels to this case, and we then show that the obtained result is related to a variation of the Lovász theta function studied by Marton. We then propose a further extension to the case of varying channels and codewords with a constant conditional composition given a particular sequence. This extension is finally applied to auxiliary channels to deduce a bound, which is useful in the low rate region and which can be interpreted as an extension of the Elias bound.
Autors: Marco Dalai;Andreas Winter;
Appeared in: IEEE Transactions on Information Theory
Publication date: Sep 2017, volume: 63, issue:9, pages: 5603 - 5617
Publisher: IEEE
 
» Constant Current Fast Charging of Electric Vehicles via a DC Grid Using a Dual-Inverter Drive
Abstract:
Existing integrated chargers are configured to charge from single- or three-phase ac networks. With the rapid emergence of dc grids, there is growing interest in the development of high-efficiency low-cost integrated chargers interfaced with dc power outlets. This paper introduces a new integrated charger offering electric vehicle fast charging from emerging dc distribution networks. In absence of a dc grid, the charger can alternatively be fed from a simple uncontrolled rectifier. The proposed charger leverages the dual-inverter topology previously developed for high-speed drive applications. By connecting the charger inlet to the differential ends of the traction inverters, charging is enabled for a wide battery voltage range previously unattainable using an integrated charger based on the single traction drive. An 11-kW experimental setup demonstrates rapid charging using constant current control and energy balancing of dual storage media. To minimize the harmonic impact of the charger on the dc distribution network, a combination of complementary and interleaved switching methods is demonstrated.
Autors: Ruoyun Shi;Sepehr Semsar;Peter W. Lehn;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 6940 - 6949
Publisher: IEEE
 
» Constellation Design Enhancement for Color-Shift Keying Modulation of Quadrichromatic LEDs in Visible Light Communications
Abstract:
Quadrichromatic light-emitting diode (QLED) cluster is a four-color solid-state apparatus suitable for simultaneous illumination and communications. Unlike traditional red/green/blue (RGB) LEDs, its extra color provides not only one new wavelength-division multiplexing data channel but also better color quality in illumination. Taking full consideration of the high quality of color rendering index (CRI) requirement with tunable color temperature (CT), this paper investigates the constellation design of color shift keying (CSK) to maximize the minimum pairwise Euclidean distance (MED) for communication performance optimization. Beyond existing works, maintaining a high-level CRI with a specified CT complicates our design optimization problem. We propose to transform the CRI requirement into a set of linear constraints on one of the LED source composition while jointly incorporating the CT constraints. Both simulation results and prototype CSK communication testbed measurements based on commercial multicolor LEDs (LUMILEDS Luxeon C) illustrate that, under the same luminous flux and CT conditions, our proposed flux independent CSK constellation for QLEDs can significantly enhance the MED, bit error rate, and illumination color qualities.
Autors: Xiao Liang;Ming Yuan;Jiaheng Wang;Zhi Ding;Ming Jiang;Chunming Zhao;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:17, pages: 3650 - 3663
Publisher: IEEE
 
» Construction $\pi _{A}$ and $\pi _{D}$ Lattices: Construction, Goodness, and Decoding Algorithms
Abstract:
A novel construction of lattices is proposed. This construction can be thought of as a special class of Construction A from codes over finite rings that can be represented as the Cartesian product of linear codes over , respectively, and hence is referred to as Construction . The existence of a sequence of such lattices that is good for channel coding (i.e., Poltyrev-limit achieving) under multistage decoding is shown. A new family of multilevel nested lattice codes based on Construction lattices is proposed and its achievable rate for the additive white Gaussian noise channel is analyzed. A generalization named Construction is also investigated, which subsumes Construction A with codes over prime fields, Construction D, and Construction as special cases.
Autors: Yu-Chih Huang;Krishna R. Narayanan;
Appeared in: IEEE Transactions on Information Theory
Publication date: Sep 2017, volume: 63, issue:9, pages: 5718 - 5733
Publisher: IEEE
 
» Construction of Highly Nonlinear 1-Resilient Boolean Functions With Optimal Algebraic Immunity and Provably High Fast Algebraic Immunity
Abstract:
In 2013, Tang, Carlet, and Tang [IEEE TIT 59(1): 653–664, 2013] presented two classes of Boolean functions. The functions in the first class are unbalanced and the functions in the second one are balanced. Both of those two classes of functions have high nonlinearity, high algebraic degree, optimal algebraic immunity, and high fast algebraic immunity. However, they are not 1-resilient which represents a drawback for their use as filter functions in stream ciphers. In this paper, we first propose a large family of 1-resilient Boolean functions having high lower bound on nonlinearity, optimal algebraic immunity, and optimal algebraic degree, that is, meeting the Siegenthaler bound. Most notably, we can mathematically prove that every function in variables belonging to this family has fast algebraic immunity no less than , which is the first time that an infinite family of 1-resilient functions with provably high fast algebraic immunity has been invented. Furthermore, we exhibit a subclass of the family which has higher lower bound on nonlinearity than all the known 1-resilient functions with (potentially) optimal algebraic immunity and potentially high fast algebraic immunity.
Autors: Deng Tang;Claude Carlet;Xiaohu Tang;Zhengchun Zhou;
Appeared in: IEEE Transactions on Information Theory
Publication date: Sep 2017, volume: 63, issue:9, pages: 6113 - 6125
Publisher: IEEE
 
» Continued Dispute on Preferred Vehicle-to-Vehicle Technologies [Connected Vehicles]
Abstract:
As reported in the June issue of IEEE Vehicular Technology Magazine [1], the National Highway Traffic Safety Administration (NHTSA) Department of Transportation has issued a proposed rule, "The Federal Motor Vehicle Safety Standard (FMVSS); Vehicle-to-Vehicle (V2V) Communications," that would require automakers to include V2V technologies in all new light-duty vehicles. The proposed rule was open for public comments until 12 April and received several replies, which were most notably from four different stakeholders, reflecting the still-ongoing heated debate about sharing the intelligent transport systems (ITS) frequency band in the United States.
Autors: Elisabeth Uhlemann;
Appeared in: IEEE Vehicular Technology Magazine
Publication date: Sep 2017, volume: 12, issue:3, pages: 17 - 20
Publisher: IEEE
 
» Continuous Estimation of Human Multi-Joint Angles From sEMG Using a State-Space Model
Abstract:
Due to the couplings among joint-relative muscles, it is a challenge to accurately estimate continuous multi-joint movements from multi-channel sEMG signals. Traditional approaches always build a nonlinear regression model, such as artificial neural network, to predict the multi-joint movement variables using sEMG as inputs. However, the redundant sEMG-data are always not distinguished; the prediction errors cannot be evaluated and corrected online as well. In this work, a correlation-based redundancy-segmentation method is proposed to segment the sEMG-vector including redundancy into irredundant and redundant subvectors. Then, a general state-space framework is developed to build the motion model by regarding the irredundant subvector as input and the redundant one as measurement output. With the built state-space motion model, a closed-loop prediction-correction algorithm, i.e., the unscented Kalman filter (UKF), can be employed to estimate the multi-joint angles from sEMG, where the redundant sEMG-data are used to reject model uncertainties. After having fully employed the redundancy, the proposed method can provide accurate and smooth estimation results. Comprehensive experiments are conducted on the multi-joint movements of the upper limb. The maximum RMSE of the estimations obtained by the proposed method is 0.16±0.03, which is significantly less than 0.25±0.06 and 0.27±0.07 (p < 0.05) obtained by common neural networks.
Autors: Qichuan Ding;Jianda Han;Xingang Zhao;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Sep 2017, volume: 25, issue:9, pages: 1518 - 1528
Publisher: IEEE
 
» Control and Emulation of Small Wind Turbines Using Torque Estimators
Abstract:
Soft-stall control of small wind turbines is a method to protect the generation system and/or load from excessive wind speeds and wind gusts without discontinuing power generation. Soft-stall can be activated due to an excess of the power and/or torque/current. This paper proposes a method to improve the existing soft-stall methods for over torque/current protection using a turbine torque estimator. In addition, this paper also proposes two methods to emulate the wind turbine inertia without communications between the load drive (wind turbine emulator) and the generation system controller. This will allow the evaluation of the proposed methods in working conditions.
Autors: Juan M. Guerrero;Carlos Lumbreras;David Díaz Reigosa;Pablo Garcia;Fernando Briz;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Sep 2017, volume: 53, issue:5, pages: 4863 - 4876
Publisher: IEEE
 
» Control of Junction Temperature and Its Rate of Change at Thermal Boundaries via Precise Loss Manipulation
Abstract:
To optimize the lifetime of switching power semiconductors, this paper presents a methodology to control power device junction temperature and its change during power cycles at thermal boundaries. This paper proposes a supervisory state machine to interrupt nominal system-level control only when temperature bounds are exceeded, and coordinates smooth transitions as and approach their respective boundaries. To ensure that thermal states are regulated via precise and independent modulation of conduction and switching loss elements, decoupling methods are proposed. Also proposed is a control law that closes a control loop on the rate of change state , and introduces active thermal capacitance and conductance into the closed-loop thermal system dynamics. Experimental evaluation of the proposed system illustrates well damped and responses, and gradual adjustment of the manipulated inputs switching frequency and duty ratio. Finally, comparison with a current limit-based regulation method illustrates how the proposed system allows power converters to push harder against their thermal limits.
Autors: Timothy Allen Polom;Boru Wang;Robert D. Lorenz;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Sep 2017, volume: 53, issue:5, pages: 4796 - 4806
Publisher: IEEE
 
» Control of Mutual Coupling in High-Field MRI Transmit Arrays in the Presence of High-Permittivity Liners
Abstract:
In high-field magnetic resonance imaging, transmit arrays and high-permittivity inserts are often used together to mitigate the effects of RF field inhomogeneities due to short wavelength. However, array performance is limited by mutual impedance between elements which must be closely spaced around the volume of interest. Mutual impedance plays a substantial role at high frequencies and is increased by the presence of dielectric pads which are used to increase the homogeneity of the RF magnetic field. This paper describes a decoupling strategy for an eight-channel transmit/receive array in the presence of a high permittivity dielectric liner. The elements are decoupled using capacitive bridges between adjacent elements. In spite of the higher mutual impedance due to the liner, both mutual resistance and reactance can be removed between adjacent elements (isolation better than 30 dB), and coupling between nonadjacent elements is maintained below 15 dB. The effects of decoupling on the transmit performance of the array in presence of high permittivity liners are investigated in terms of coupling, magnetic field intensity, SAR and transmit efficiencies.
Autors: Atefeh Kordzadeh;Nicola De Zanche;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3485 - 3491
Publisher: IEEE
 
» Control of Widely Tunable Lasers With High-Q Resonator as an Integral Part of the Cavity
Abstract:
We have designed and fabricated widely tunable semiconductor laser with a high-Q resonator as an integral part of the laser cavity. Wide tuning is realized by utilizing the Vernier effect of two rings with slightly different circumferences. A third ring with considerably larger circumference, and, consequently, higher Q is introduced inside the laser cavity. We study the control of such a laser and show that it is straightforward provided that the integrated laser has on-chip monitor photodiodes. This further shows the benefits of full integration as inclusion of additional monitor photodetectors is straightforward with no extra processing steps. As the complexity of photonic-integrated chips increases, the inclusion of more monitor photodetectors for control is necessary.
Autors: Tin Komljenovic;Songtao Liu;Erik Norberg;Gregory A. Fish;John E. Bowers;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:18, pages: 3934 - 3939
Publisher: IEEE
 
» Control Scheme for Open-Ended Induction Motor Drives With a Floating Capacitor Bridge Over a Wide Speed Range
Abstract:
An electric drive for high-speed applications is analyzed in this paper. The drive consists of a dual two-level inverter with a floating bridge, fed by a single voltage source, and a three-phase induction motor with open-ended stator windings. The floating bridge compensates the reactive power of the motor, so that the main inverter operates at unity power factor and fully exploits its current capability. The constant power speed range of the motor can be significantly extended depending on the dc-link voltage of the floating inverter. The details of the control system are examined and the feasibility of an electric drive is experimentally assessed.
Autors: Michele Mengoni;Albino Amerise;Luca Zarri;Angelo Tani;Giovanni Serra;Domenico Casadei;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Sep 2017, volume: 53, issue:5, pages: 4504 - 4514
Publisher: IEEE
 
» Control Strategy for a Modified Cascade Multilevel Inverter With Dual DC Source for Enhanced Drivetrain Operation
Abstract:
This paper presents a new control strategy for a modified cascade multilevel inverter used in drivetrain operations. The proposed inverter is a three-phase bridge with its dc link fed by a dc source (battery), and each phase series-connected to an H-bridge fed with a floating dc source (ultracapacitor). To exploit the potentials of the inverter for enhanced drivetrain performance, a sophisticated yet efficient modulation method is proposed to optimize energy transfer between the dc sources and with the load (induction motor) during typical operations, and to minimize switching losses and harmonics distortion. Detailed analysis of the proposed control method is presented, which is supported by experimental verifications.
Autors: Maciej S. Bendyk;Patrick Chi-Kwong Luk;Mohammed H. Alkhafaji;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Sep 2017, volume: 53, issue:5, pages: 4655 - 4664
Publisher: IEEE
 
» Control Strategy to Eliminate Impact of Voltage Measurement Errors on Grid Current Performance of Three-Phase Grid-Connected Inverters
Abstract:
This study proposes an advanced current control strategy for three-phase grid-connected inverters to reject the impact of the dc offsets and scaling errors in the grid voltage measurement on the grid current performance. The proposed current controller designed in the synchronous (d-q) reference frame is developed with a proportional integral (PI) plus three vector PI controllers. The PI controller regulates the fundamental current to follow its reference, meanwhile, three vector PI controllers tuned at the fundamental grid frequency (), , are employed to eliminate the dc, unbalance, harmonic components in the grid current. As a result, the three-phase grid currents are controlled to be balanced, sinusoidal, and extremely low dc component despite the presence of the dc offset and scaling errors in the grid voltage measurement and distorted grid voltage conditions. The main advantage of the proposed control scheme is that it is developed without the need of additional hardware circuit, dc extraction, and harmonic detection scheme so that it can be integrated into the existing grid-connected inverter system without extra cost. The effectiveness of the suggested solution is verified by experimental results under various grid voltage conditions and the grid voltage measurement errors.
Autors: Quoc-Nam Trinh;Fook Hoong Choo;Peng Wang;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7508 - 7519
Publisher: IEEE
 
» Controller-centric combinatorial wrap-around interaction testing to evaluate a stateful PCE-based transport network architecture
Abstract:
The objective of this paper is to develop a controller-centric combinatorial wrap-around interaction testing methodology for a stateful path computation element (PCE)-based transport network architecture. By exploiting the internal contexts of the controller-centric network in conjunction with combinatorial, wrap-around, and interaction testing methodologies, the proposed testing methodology helps test engineers build a highly configurable testing environment, select high-quality test cases to obtain the best possible combination of interactions, and prune fault cases or useless cases from all possible test cases throughout the entire development process as gray-box testing. The experimental results verify that the combined testing methodology effectively evaluates the controller-centric network for all testing processes in a completely controlled environment.
Autors: Jin Seek Choi;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Sep 2017, volume: 9, issue:9, pages: 792 - 802
Publisher: IEEE
 
» Controlling Soft Robots: Balancing Feedback and Feedforward Elements
Abstract:
Soft robots (SRs) represent one of the most significant recent evolutions in robotics. Designed to embody safe and natural behaviors, they rely on compliant physical structures purposefully designed to embody desirable and sometimes variable impedance characteristics. This article discusses the problem of controlling SRs. We start by observing that most of the standard methods of robotic control-e.g., high-gain robust control, feedback linearization, backstepping, and active impedance control-effectively fight against or even completely cancel the physical dynamics of the system, replacing them with a desired model. This defeats the purpose of introducing physical compliance. After all, what is the point of building soft actuators if we then make them stiff by control?
Autors: Cosimo Della Santina;Matteo Bianchi;Giorgio Grioli;Franco Angelini;Manuel Catalano;Manolo Garabini;Antonio Bicchi;
Appeared in: IEEE Robotics & Automation Magazine
Publication date: Sep 2017, volume: 24, issue:3, pages: 75 - 83
Publisher: IEEE
 
» Cooperation of Wind Power and Battery Storage to Provide Frequency Regulation in Power Markets
Abstract:
In the future power system with high penetration of renewables, renewable energy is expected to undertake part of the responsibility for frequency regulation, just as the conventional generators. Wind power and battery storage are complementary in accuracy and durability when providing frequency regulation. Therefore, it would be profitable to combine wind power and battery storage as a physically connected entity or a virtual power plant to provide both energy and frequency regulation in the markets. This paper proposes a real-time cooperation scheme to exploit their complementary characteristics and an optimal bidding strategy for them in joint energy and regulation markets, considering battery cycle life. The proposed cooperation scheme is adopted in a real-time battery operating simulation and then incorporated into the optimal bidding model. The scheme could improve the wind regulation performance score and allow for more regulation bids without affecting the battery life, thus significantly increasing the overall revenue. The validity of the proposed scheme and strategy are proved by the case study.
Autors: Guannan He;Qixin Chen;Chongqing Kang;Qing Xia;Kameshwar Poolla;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3559 - 3568
Publisher: IEEE
 
» Cooperation-Based Probabilistic Caching Strategy in Clustered Cellular Networks
Abstract:
This letter will discuss the probabilistic caching strategies in spatially clustered cellular networks. Thanks to the content preference of mobile users, proactive caching can be adopted as a promising technique to diminish the backhaul traffic and to decrease the content delivery latency. However, basically there are two obstacles to accomplish the caching policy, i.e., the limited storage capacity of small cells to cache large amount of multimedia contents, and the too small number of users under each base station to imply the content aggregation effect. Traditional caching strategies of the base station only concern its local requests from the connected users through wireless links, but neglect the potential benefit from the cluster feature of the network infrastructure and user traffic demand. In this letter, we proposed a new policy called "Caching as a Cluster", where small cells can exchange content with each other to fulfill every user request within the cluster of base stations. Intuitively, this cooperation between base stations makes a difference to decrease the content delivery latency of mobile users in clustered cellular networks as testified in our numerical simulation.
Autors: Yifan Zhou;Zhifeng Zhao;Rongpeng Li;Honggang Zhang;Yves Louet;
Appeared in: IEEE Communications Letters
Publication date: Sep 2017, volume: 21, issue:9, pages: 2029 - 2032
Publisher: IEEE
 
» Cooperation-Driven Distributed Control Scheme for Large-Scale Wind Farm Active Power Regulation
Abstract:
Being more actively involved in the electricity market and power systems, wind farms are urgently expected to have similar controllable behavior to conventional generations so that demand assigned by the system operator can be met. However, determining the method of dispatching the reference among the widely spread and low-rating wind turbines is difficult. This paper provides a cooperation-driven distributed control scheme for wind farm active power regulation. Instead of competing with neighboring controllers completely, the control strategy evaluates system-wide impacts of local control actions, and aims to achieve coordinated control effect. In addition, the kinetic energy storage potential in a wind turbine is tapped to provide a buffer for power dispatch. Case studies demonstrate that a large wind farm can be effectively controlled to accurately track the demand power through the proposed control scheme.
Autors: Xiaodan Gao;Ke Meng;Zhao Yang Dong;Dongxiao Wang;Mohamed Shawky El Moursi;Kit Po Wong;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 1240 - 1250
Publisher: IEEE
 
» Cooperative Jamming for Secure Communication With Finite Alphabet Inputs
Abstract:
This letter considers cooperative jamming to secure communication in the presence of multiple eavesdroppers with finite alphabet inputs. Considering the global constraint, the joint design of artificial noise covariance matrices and power allocation between the source and the relays is studied. Specifically, we transformed the problem of artificial noise design into a semi-definite programming problem, which is efficiently solved by standard optimization method. Besides, the power allocation between the source and relays is derived by utilizing the relationship between mutual information and minimum mean square error. Furthermore, a two-step algorithm is developed to enhance the achievable secrecy rate of cooperative jamming wireless network. Numerical examples demonstrate the proposed algorithm achieves a significant gain over the conventional counterparts in terms of secrecy rate.
Autors: Kuo Cao;Yueming Cai;Yongpeng Wu;Weiwei Yang;
Appeared in: IEEE Communications Letters
Publication date: Sep 2017, volume: 21, issue:9, pages: 2025 - 2028
Publisher: IEEE
 
» Cooperative Multicast With Location Aware Distributed Mobile Relay Selection: Performance Analysis and Optimized Design
Abstract:
Mobile relay (MR) selection is critical to the performance and realization of two-stage cooperative multicast (CM). Targeting at the energy efficiency and simplified realization, a location-aware distributed (LAD) MR selection method is proposed, where successful mobile stations (MSs) at the first stage that are farther from the base station would activate themselves to be MRs with higher probabilities. Assuming that the number of MRs close to an unsuccessful MS follows Poisson Point Process distribution, based on stochastic geometry, the coverage performance of two-stage CM with LAD MR selection can be numerically evaluated. Moreover, given the analytical results, an optimized LAD MR selection scheme can be designed, aiming at minimizing the total power consumption of two-stage CM. Numerical and simulation results verify that the analysis based on stochastic geometry is accurate. Overall, the optimized LAD MR scheme provides better energy efficiency and coverage performance than existing distributed MR schemes.
Autors: Yiqing Zhou;Hang Liu;Zhengang Pan;Lin Tian;Jinglin Shi;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Sep 2017, volume: 66, issue:9, pages: 8291 - 8302
Publisher: IEEE
 
» Coordinated Control Strategies for Offshore Wind Farm Integration via VSC-HVDC for System Frequency Support
Abstract:
Coordinated control strategies to provide system inertia support for main grid from offshore wind farm that is integrated through HVdc transmission is the subject matter of this paper. The strategy that seeks to provide inertia support to the main grid through simultaneous utilization of HVdc capacitors energy, and wind turbines (WTs) inertia without installing the remote communication of two HVdc terminals is introduced in details. Consequently, a novel strategy is proposed to improve system inertia through sequentially exerting dc capacitors energy and then WTs inertia via a cascading control scheme. Both strategies can effectively provide inertia support while the second one minimizes the control impacts on harvesting wind energy with the aid of communication between onshore and offshore ac grids. Case studies of a wind farm connecting with a HVdc system considering sudden load variations have been successfully conducted to compare and demonstrate the effectiveness of the control strategies in DIgSILENT/PowerFactory.
Autors: Yujun Li;Zhao Xu;Jacob Østergaard;David J. Hill;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 843 - 856
Publisher: IEEE
 
» Coordinated Multi-Area Economic Dispatch via Critical Region Projection
Abstract:
A coordinated economic dispatch method for multiarea power systems is proposed. Choosing boundary phase angles as coupling variables, the proposed method exploits the structure of critical regions in local problems defined by active and inactive constraints. For a fixed boundary state given by the coordinator, local operators compute the coefficients of critical regions containing the boundary state and the optimal value functions then communicate them to the coordinator who in turn optimizes the boundary state to minimize the overall cost. By iterating between local operators and the coordinator, the proposed algorithm converges to the global optimal solution in finite steps, and it requires limited information sharing.
Autors: Ye Guo;Lang Tong;Wenchuan Wu;Boming Zhang;Hongbin Sun;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3736 - 3746
Publisher: IEEE
 
» Coordination Over Multi-Agent Networks With Unmeasurable States and Finite-Level Quantization
Abstract:
In this note, the coordination of linear discrete-time multi-agent systems over digital networks is investigated with unmeasurable states in agents' dynamics. The quantized-observer based communication protocols and Certainty Equivalence principle based control protocols are proposed to characterize the inter-agent communication and the cooperative control in an integrative framework. By investigating the structural and asymptotic properties of the equations of stabilization and estimation errors, which are nonlinearly coupled by the finite-level quantization scheme, some necessary conditions and sufficient conditions are given for the existence of such communication and control protocols to ensure the inter-agent state observation and cooperative stabilization. It is shown that these conditions come down to the simultaneous stabilizability and the detectability of the dynamics of agents and the structure of the communication network.
Autors: Yang Meng;Tao Li;Ji-Feng Zhang;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Sep 2017, volume: 62, issue:9, pages: 4647 - 4653
Publisher: IEEE
 
» CoRQ: Enabling Runtime Reconfiguration Under WCET Guarantees for Real-Time Systems
Abstract:
Real-time systems have an increasing demand for predictable performance. Only recently novel models and analyses were proposed that make the performance benefits of runtime-reconfigurable architectures accessible for optimized worst-case execution time (WCET) guarantees. However, the implicit assumption in these works is that the process of reconfiguration itself complies with execution time guarantees. The realization of a reconfiguration controller that fulfills these assumptions and that is amenable to WCET guarantees is so far unavailable. In this letter, we detail the challenges of runtime reconfiguration in real-time systems and show that conflicts while accessing a shared main memory during reconfiguration can lead to a slowdown of more than in reconfiguration bandwidth. We present concepts that enable runtime reconfiguration under WCET guarantees and release our implementation of these concepts as open source.
Autors: Marvin Damschen;Lars Bauer;Jörg Henkel;
Appeared in: IEEE Embedded Systems Letters
Publication date: Sep 2017, volume: 9, issue:3, pages: 77 - 80
Publisher: IEEE
 
» Correcting Instrumental Variation and Time-Varying Drift Using Parallel and Serial Multitask Learning
Abstract:
When instruments and sensor systems are used to measure signals, the posterior distribution of test samples often drifts from that of the training ones, which invalidates the initially trained classification or regression models. This may be caused by instrumental variation, sensor aging, and environmental change. We introduce transfer-sample-based multitask learning (TMTL) to address this problem, with a special focus on applications in machine olfaction. Data collected with each device or in each time period define a domain. Transfer samples are the same group of samples measured in every domain. They are used by our method to share knowledge across domains. Two paradigms, parallel and serial transfer, are designed to deal with different types of drift. A dynamic model strategy is proposed to predict samples with known acquisition time. Experiments on three real-world data sets confirm the efficacy of the proposed methods. They achieve good accuracy compared with traditional feature-level drift correction algorithms and typical labeled-sample-based MTL methods, with few transfer samples needed. TMTL is a practical algorithm framework which can greatly enhance the robustness of sensor systems with complex drift.
Autors: Ke Yan;David Zhang;Yong Xu;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Sep 2017, volume: 66, issue:9, pages: 2306 - 2316
Publisher: IEEE
 
» Correcting Satellite Passive Microwave Brightness Temperatures in Forested Landscapes Using Satellite Visible Reflectance Estimates of Forest Transmissivity
Abstract:
Forest cover attenuation of microwave emission is a significant challenge to the estimation of snow accumulation from remote sensing microwave observations because canopy biomass attenuates the understory snowcover emission and produces additional emission to that generated by the snowpack and subnivean surface. Transmissivity of radiation is an important variable that describes how a tree canopy attenuates microwave emission from the ground. Although it can be measured in the field or estimated by models using field data at the in situ scale, the estimation of transmissivity at regional to global scales is a challenge. Following the work of Metsämäki et al. (2005), a transmissivity model that uses reflectance data from the moderate resolution imaging spectroradiometer is applied to estimate transmissivity at global scales. The influence of the vegetation attenuation and the emission on the brightness temperature (Tb), which is observed by advanced microwave scanning radiometer-Earth observing system sensor , can be calculated by comparing the Tb of the ground below-canopy with the Tb above the forest canopy during the presnow season. Linear regression models derived between transmissivity estimates and the had significant R 2 values of 0.76 (0.96) at 18 GHz vertical (horizontal) polarization and 0.91 (0.91) at 36 GHz vertical (horizontal) polarization.
Autors: Qinghuan Li;Richard E. J. Kelly;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Sep 2017, volume: 10, issue:9, pages: 3874 - 3883
Publisher: IEEE
 
» Correction to “Automatic Quality Assessment of Echocardiograms Using Convolutional Neural Networks: Feasibility on the Apical Four-Chamber View”
Abstract:
In the above paper [1], the first footnote should have indicated the following information: A. H. Abdi and C. Luong are joint first authors.
Autors: A. H. Abdi;C. Luong;T. Tsang;G. Allan;S. Nouranian;J. Jue;D. Hawley;S. Fleming;K. Gin;J. Swift;R. Rohling;P. Abolmaesumi;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Sep 2017, volume: 36, issue:9, pages: 1992 - 1992
Publisher: IEEE
 
» Correction to “Fast Mode Selection for HEVC Intra-Frame Coding With Entropy Coding Refinement Based on a Transparent Composite Model”
Abstract:
After our internal code cross-check, we have recently found some mistakes in [1, Table VIII] and [1, Figs. 12 and 13]. As such, we have reimplemented the ideas and methods stated in [1]. The corrected Table VIII and Figs. 12 and 13 are now shown in this correction. Our code is also available from http://multicom.uwaterloo.ca. To reflect this correction, the following changes have to be made accordingly throughout the paper [1].
Autors: Nan Hu;En-Hui Yang;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Sep 2017, volume: 27, issue:9, pages: 2055 - 2056
Publisher: IEEE
 
» Corrections on “Symbol Flipping Decoding Algorithms Based on Prediction for Non-Binary LDPC Codes”
Abstract:
Due to a production error, an equation in the above paper [1] appeared incorrectly. Below is the correct version.
Autors: S. Wang;Q. Huang;Z. Wang;
Appeared in: IEEE Transactions on Communications
Publication date: Sep 2017, volume: 65, issue:9, pages: 4099 - 4099
Publisher: IEEE
 
» Corrections to “A 10/20/30/40 MHz Feed-Forward FIR DAC Continuous-Time $\Delta \Sigma $ ADC With Robust Blocker Performance for Radio Receivers”
Abstract:
In [1], Table I compares the state of the art in CT ADCs. Unfortunately, due to a mistake, the FOM [Schreier] (dB) reported is 3 dB below its actual value. Table I in [1] is reprinted as Table I. The authors regret their mistake.
Autors: Sebastian Loeda;Jeffrey Harrison;Franck Pourchet;Andrew Adams;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Sep 2017, volume: 52, issue:9, pages: 2515 - 2515
Publisher: IEEE
 
» Corrections to “Multilevel MVDC Link Strategy of High-Frequency-Link DC Transformer Based on Switched Capacitor for MVDC Power Distribution”
Abstract:
Presents corrections to the paper, “Multilevel MVDC Link Strategy of High-Frequency-Link DC Transformer Based on Switched Capacitor for MVDC Power Distribution,” (Wang, Y., et al), IEEE Trans. Ind. Electron. vol. 64, no. 4, pp. 2829–2835, Apr. 2017.
Autors: Yu Wang;Qiang Song;Qianhao Sun;Biao Zhao;Jianguo Li;Wenhua Liu;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7280 - 7280
Publisher: IEEE
 
» Corrections to “Fundamental Efficiency Limits for Small Metallic Antennas”
Abstract:
In [1], it was stated that “An attempt to establish bounds on the maximum achievable gain and efficiency using a “loss merit factor” is reported in [2]. However, the results are clearly unphysical, since a single turn loop antenna can surpass these fundamental limits when ” [3].
Autors: Carl Pfeiffer;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Sep 2017, volume: 65, issue:9, pages: 4958 - 4958
Publisher: IEEE
 
» Corrections to “Resource Allocation for D2D-Enabled Vehicular Communications”
Abstract:
In the above paper [1], the text discussion of several equations were misrepresented. Below is the corrected text of Sections III and IV, in which the errors appear.
Autors: L. Liang;G. Y. Li;W. Xu;
Appeared in: IEEE Transactions on Communications
Publication date: Sep 2017, volume: 65, issue:9, pages: 4096 - 4098
Publisher: IEEE
 
» Correntropy Maximization via ADMM: Application to Robust Hyperspectral Unmixing
Abstract:
In hyperspectral images, some spectral bands suffer from low signal-to-noise ratio due to noisy acquisition and atmospheric effects, thus requiring robust techniques for the unmixing problem. This paper presents a robust supervised spectral unmixing approach for hyperspectral images. The robustness is achieved by writing the unmixing problem as the maximization of the correntropy criterion subject to the most commonly used constraints. Two unmixing problems are derived: the first problem considers the fully constrained unmixing, with both the nonnegativity and sum-to-one constraints, while the second one deals with the nonnegativity and the sparsity promoting of the abundances. The corresponding optimization problems are solved using an alternating direction method of multipliers (ADMM) approach. Experiments on synthetic and real hyperspectral images validate the performance of the proposed algorithms for different scenarios, demonstrating that the correntropy-based unmixing with ADMM is particularly robust against highly noisy outlier bands.
Autors: Fei Zhu;Abderrahim Halimi;Paul Honeine;Badong Chen;Nanning Zheng;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Sep 2017, volume: 55, issue:9, pages: 4944 - 4955
Publisher: IEEE
 
» Cost-Effective Enhancement on Both Yield and Reliability for Cache Designs Based on Performance Degradation Tolerance
Abstract:
Guaranteeing functional correctness of cache memories is crucial for computer designs. In the literature, there have been several works addressing this issue. However, fault tolerability of these methods may be limited. In this paper, we present a new cache architecture that has flexible tolerability. Moreover, by using the proposed architecture, both yield and reliability of the cache can be enhanced simultaneously. In our cache, a particular type of cache blocks called tolerable block is further identified among the faulty ones. Such blocks can still be used during cache access in our architecture, while accessing to intolerable blocks will result in additional cache misses, and therefore performance degradation. The number of tolerable cache blocks is thus critical for the achievable yield and reliability enhancement, as well as the incurred cost on performance. In this work, error correcting code (ECC) methods are employed to increase the number of tolerable blocks. In particular, we propose to embed the required check bits in one of the cache ways. Analysis results show that this embedding method only incurs minor performance degradation, while the incurred area overhead due to ECC can thus be significantly reduced from 5.92% to only 0.92%. General applicability of the embedding method to ordinary ECC methods is also investigated. Experimental results show that the performance degradation can be reduced from 16% to only 1.53% by using the proposed cache. This leads to great tolerability improvement, and thus the yield and reliability are enhanced very significantly when compared with the previous work.
Autors: Tong-Yu Hsieh;Tsung-Liang Chih;Mei-Jung Wu;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Sep 2017, volume: 25, issue:9, pages: 2434 - 2448
Publisher: IEEE
 
» Cost-Efficient Cellular Networks Powered by Micro-Grids
Abstract:
This paper investigates a cellular network powered by a micro-grid (MG) in the context of green communications, which integrates the conventional generators, energy storage devices, and renewable energy generators, so as to supply electricity to base stations (BSs). Under this model, we study the efficiency aspect of the MG-powered cellular network from the economical perspective. Specifically, the concept of cost efficiency (CE) is employed to measure the sum rate delivered per dollar. Then, our goal is to maximize this CE subject to a series of constraints, including multi-variable coupling and time coupling constraints. Particularly, we assume the zero-forcing beamforming scheme employed by the BSs. To address this established fractional CE optimization problem, we first apply the Dinkelbach method, and then propose a low-complexity algorithm based on the alternating direction method of multipliers approach to jointly schedule power generation in the MG and optimize transmit power for BSs. We introduce a number of auxiliary variables to design a special variable splitting scheme so that the coupling inequality constraints can be separable among two variable sets. Consequently, the proposed algorithm only incorporates simple updates in each step and thus can be implemented in a parallel and completely distributed fashion. Simulation results demonstrate the convergence and energy scheduling performance of the proposed algorithm.
Autors: Ling Zhang;Yunlong Cai;Qingjiang Shi;Guanding Yu;Geoffrey Ye Li;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Sep 2017, volume: 16, issue:9, pages: 6047 - 6061
Publisher: IEEE
 
» Coupled Split-Ring Resonator Circular Polarization Selective Surface
Abstract:
A novel class of circular polarization selective surfaces (CPSSs) consisting of a pair of planar split-ring resonator arrays is proposed. A significant advantage of the proposed structure over existing designs is its manufacturing simplicity compatible with standard printed technology processes. Its operating principle is reviewed alongside that of the Pierrot cell and in light of the linear polarization reflection and transmission characteristics of CPSSs. Guidelines for the initial design of the proposed CPSS concept are thus derived. Further design considerations and tradeoffs are also discussed. The validity of the concept is confirmed by means of a design example entailing a right-hand CPSS at 20 GHz. Full-wave simulation results and experimental testing on a fabricated prototype are presented and agree well with the theoretical predictions.
Autors: Wenxing Tang;George Goussetis;Nelson J. G. Fonseca;Hervé Legay;Elena Sáenz;Peter de Maagt;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Sep 2017, volume: 65, issue:9, pages: 4664 - 4675
Publisher: IEEE
 
» Coupling Quality [Enigmas, etc.]
Abstract:
Various puzzles, games, humorous definitions, or mathematical that should engage the interest of readers.
Autors: Takashi Ohira;
Appeared in: IEEE Microwave Magazine
Publication date: Sep 2017, volume: 18, issue:6, pages: 154 - 154
Publisher: IEEE
 
» Coverage Contribution Area Based $k$ -Coverage for Wireless Sensor Networks
Abstract:
Coverage is a primary metric for ensuring the quality of services provided by a wireless sensor network (WSN). In this paper, we focus on the -coverage problem, which requires a selection of a minimum subset of nodes among the deployed ones such that each point in the target region is covered by at least nodes. We present both centralized and distributed protocols to tackle this fundamental problem. Our protocols are based on a novel concept of Coverage Contribution Area, which helps to get a lower sensor spatial density. Furthermore, our protocols take the residual energies of the sensors into consideration. This consideration combined with the low sensor spatial density ensures that our protocols can prolong the network lifetime to a greater extent, which is crucial to WSNs due to the limited energy supply and the difficulties of energy recharging. We also conduct extensive simulations to verify our proposed algorithms, and the results show that they are superior over existing ones.
Autors: Jiguo Yu;Shengli Wan;Xiuzhen Cheng;Dongxiao Yu;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Sep 2017, volume: 66, issue:9, pages: 8510 - 8523
Publisher: IEEE
 

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