Electrical and Electronics Engineering publications abstract of: 01-2018 sorted by title, page: 6

» Deep Multiple Instance Learning-Based Spatial–Spectral Classification for PAN and MS Imagery
Abstract:
Panchromatic (PAN) and multispectral (MS) imagery classification is one of the hottest topics in the field of remote sensing. In recent years, deep learning techniques have been widely applied in many areas of image processing. In this paper, an end-to-end learning framework based on deep multiple instance learning (DMIL) is proposed for MS and PAN images’ classification using the joint spectral and spatial information based on feature fusion. There are two instances in the proposed framework: one instance is used to capture the spatial information of PAN and the other is used to describe the spectral information of MS. The features obtained by the two instances are concatenated directly, which can be treated as simple fusion features. To fully fuse the spatial–spectral information for further classification, the simple fusion features are fed into a fusion network with three fully connected layers to learn the high-level fusion features. Classification experiments carried out on four different airborne MS and PAN images indicate that the classifier provides feasible and efficient solution. It demonstrates that DMIL performs better than using a convolutional neural network and a stacked autoencoder network separately. In addition, this paper shows that the DMIL model can learn and fuse spectral and spatial information effectively, and has huge potential for MS and PAN imagery classification.
Autors: Xu Liu;Licheng Jiao;Jiaqi Zhao;Jin Zhao;Dan Zhang;Fang Liu;Shuyuan Yang;Xu Tang;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jan 2018, volume: 56, issue:1, pages: 461 - 473
Publisher: IEEE
 
» Deep Temporal Multimodal Fusion for Medical Procedure Monitoring Using Wearable Sensors
Abstract:
Process monitoring and verification have a wide range of uses in the medical and healthcare fields. Currently, such tasks are often carried out by a trained specialist, which makes them expensive, inefficient, and time-consuming. Recent advances in automated video- and multimodal-data-based action and activity recognition have made it possible to reduce the extent of manual intervention required to effectively carry out process supervision tasks. In this paper, we propose algorithms for automated egocentric human action and activity recognition from multimodal data, with a target application of monitoring and assisting a user perform a multistep medical procedure. We propose a supervised deep multimodal fusion framework that relies on concurrent processing of motion data acquired with wearable sensors and video data acquired with an egocentric or body-mounted camera. We demonstrate the effectiveness of the algorithm on a public multimodal dataset and conclude that automated process monitoring via the use of multiple heterogeneous sensors is a viable alternative to its manual counterpart. Furthermore, we demonstrate that the application of previously proposed adaptive sampling schemes to the video processing branch of the multimodal framework results in significant performance improvements.
Autors: Edgar A. Bernal;Xitong Yang;Qun Li;Jayant Kumar;Sriganesh Madhvanath;Palghat Ramesh;Raja Bala;
Appeared in: IEEE Transactions on Multimedia
Publication date: Jan 2018, volume: 20, issue:1, pages: 107 - 118
Publisher: IEEE
 
» DeepEyes: Progressive Visual Analytics for Designing Deep Neural Networks
Abstract:
Deep neural networks are now rivaling human accuracy in several pattern recognition problems. Compared to traditional classifiers, where features are handcrafted, neural networks learn increasingly complex features directly from the data. Instead of handcrafting the features, it is now the network architecture that is manually engineered. The network architecture parameters such as the number of layers or the number of filters per layer and their interconnections are essential for good performance. Even though basic design guidelines exist, designing a neural network is an iterative trial-and-error process that takes days or even weeks to perform due to the large datasets used for training. In this paper, we present DeepEyes, a Progressive Visual Analytics system that supports the design of neural networks during training. We present novel visualizations, supporting the identification of layers that learned a stable set of patterns and, therefore, are of interest for a detailed analysis. The system facilitates the identification of problems, such as superfluous filters or layers, and information that is not being captured by the network. We demonstrate the effectiveness of our system through multiple use cases, showing how a trained network can be compressed, reshaped and adapted to different problems.
Autors: Nicola Pezzotti;Thomas Höllt;Jan Van Gemert;Boudewijn P.F. Lelieveldt;Elmar Eisemann;Anna Vilanova;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 98 - 108
Publisher: IEEE
 
» Degradation Behavior of Lithium-Ion Batteries During Calendar Ageing—The Case of the Internal Resistance Increase
Abstract:
Lithium-ion batteries are regarded as the key energy storage technology for both e-mobility and stationary renewable energy storage applications. Nevertheless, Lithium-ion batteries are complex energy storage devices, which are characterized by a complex degradation behavior, which affects both their capacity and internal resistance. This paper investigates, based on extended laboratory calendar ageing tests, the degradation of the internal resistance of a lithium-ion battery. The dependence of the internal resistance increase on the temperature and state-of-charge level has been extensive studied and quantified. Based on the obtained laboratory results, an accurate semiempirical lifetime model, which is able to predict with high accuracy the internal resistance increase of the lithium-ion battery over a wide temperature range and for all state-of-charge levels, was proposed and validated.
Autors: Daniel-Ioan Stroe;Maciej Swierczynski;Søren Knudsen Kær;Remus Teodorescu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 517 - 525
Publisher: IEEE
 
» Delay Analysis and Time-Critical Protocol Design for In-Vehicle Power Line Communication Systems
Abstract:
With the emerging automated tasks in vehicle domain, the development of in-vehicle communications is increasingly important and subjected to new applications. The use of vehicular power lines has been a promising alternative to in-vehicle communications because of elimination of extra data cables. In this paper, we focus on the latest HomePlug Green PHY (HPGP) and explore its opportunity to support time-critical in-vehicle applications. Specifically, we apply network calculus to evaluate the worst access and queuing delay of various priority flows in vehicle bus networks. In order to maximize the bandwidth utility and satisfy the end-to-end hard delay requirements, we further propose a bandwidth efficient fair rate scheduling and delay sensitive traffic shaper. Performance evaluation supplemented by numerical and simulation results is also provided to show the advantage of HPGP and the proposed traffic shaper over the existing industry solutions.
Autors: Zhengguo Sheng;Daxin Tian;Victor C. M. Leung;Gaurav Bansal;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2018, volume: 67, issue:1, pages: 3 - 16
Publisher: IEEE
 
» Delay Effects on Consensus-Based Distributed Economic Dispatch Algorithm in Microgrid
Abstract:
For microgrids with connected but sparse communication networks, consensus-based approach can provide a distributed solution to the economic dispatch problem. However, as time delays in communication networks are nonnegligible, performances of consensus-based distributed economic dispatch algorithms are not well disclosed and investigated. Considering the effects of time delays, we first provide a novel consensus-based economic dispatch algorithm. The algorithm is fully distributed such that the optimal dispatch of energy resources in microgrid can be implemented in a distributed manner. The influence of time delays on distributed economic dispatch is strictly analyzed. The maximum allowable delay bounds are derived by applying the generalized Nyquist criterion. Several simulations are presented to verify the effectiveness of the algorithm and the correctness of the theoretical results.
Autors: Gang Chen;Zhongyuan Zhao;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 602 - 612
Publisher: IEEE
 
» Delay Monitoring System With Multiple Generic Monitors for Wide Voltage Range Operation
Abstract:
As the semiconductor process technology continuously scales down, circuit delay variations due to manufacturing and environmental variations become more and more serious. These delay variations are hardly predictable and thus require an additional design margin, which impedes the chance to reduce the area and power consumption of a chip. One of the best solutions to alleviate this problem is to measure circuit delays at run time and control the supply voltage accordingly through a closed-loop dynamic voltage and frequency scaling (DVFS) scheme. The key issue of this scheme is the delay mismatch between the monitoring circuit and the target block. A large delay mismatch might lose the advantage of the closed-loop DVFS. It becomes much worse as a circuit block operates in wider voltage range, from near-threshold voltage to super-overdrive voltage. This paper proposes novel delay monitoring systems with multiple generic monitors for wide voltage range operation, which provide a better delay correlation between the monitoring circuit and the target block compared to conventional monitoring approaches. The proposed approaches reduce the maximum error by up to 91% for a popular processor core in a 14-nm FinFET process technology, thereby bring a decrease of design margin, lower-power, and/or lower-cost design.
Autors: Jongho Kim;Kiyoung Choi;Yonghwan Kim;Wook Kim;Kyungtae Do;Jungyun Choi;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jan 2018, volume: 26, issue:1, pages: 37 - 49
Publisher: IEEE
 
» Deliverable Robust Ramping Products in Real-Time Markets
Abstract:
The increasing penetration of variable energy resources has led to more uncertainties in power systems. Flexible Ramping Products (FRP) have been adopted by several electricity markets to manage the uncertainties. We reveal that neglected line congestion for FRP may not only cause infeasibility, but also result in a failure of cost recovery. To address the deliverability issues on FRP, this paper proposes a new concept, Deliverable Robust Ramping Products (DRRP), in real-time markets. The DRRP includes generation ramping reserve and generation capacity reserve. The DRRP is deliverable and immunized against any predefined uncertainty. It also fully addresses the bid cost recovery issue caused by the line congestion in existing FRPs. The prices of DRRP are derived within the Affine Adjustable Robust Optimization (AARO) framework. These prices can be used to identify valuable reserves among available reserves and quantify the values of flexible resources that provide reserves. This paper also proposes a general approach to obtaining the time-decoupled prices for DRRP and generation, which can be used for the market settlement of the first interval only in real-time markets. Simulations on a 3-bus system and the IEEE 118-bus system are performed to illustrate the concept of DRRP and the advantages of DRRP compared to existing FRP.
Autors: Hongxing Ye;Zuyi Li;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 5 - 18
Publisher: IEEE
 
» Demand Response of Ancillary Service From Industrial Loads Coordinated With Energy Storage
Abstract:
As one of the featured initiatives in smart grids, demand response is enabling active participation of electricity consumers in the supply/demand balancing process, thereby enhancing the power system's operational flexibility in a cost-effective way. Industrial load plays an important role in demand response because of its intense power consumption, already existing advanced monitoring, and control infrastructure, and its strong economic incentive due to the high energy costs. As typical industrial loads, cement plants are able to quickly adjust their power consumption rate by switching on/off the crushers. However, in the cement plant as well as other industrial loads, switching on/off the loading units only achieves discrete power changes, which restricts the load from offering valuable ancillary services such as regulation and load following, as continuous power changes are required for these services. In this paper, we overcome this restriction of poor granularity by proposing methods that enable these loads to provide regulation or load following with the support of an onsite energy storage system.
Autors: Xiao Zhang;Gabriela Hug;J. Zico Kolter;Iiro Harjunkoski;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 951 - 961
Publisher: IEEE
 
» Demand-Side Management by Regulating Charging and Discharging of the EV, ESS, and Utilizing Renewable Energy
Abstract:
The evolution in microgrid technologies as well as the integration of electric vehicles (EVs), energy storage systems (ESSs), and renewable energy sources will all play a significant role in balancing the planned generation of electricity and its real-time use. We propose a real-time decentralized demand-side management (RDCDSM) to adjust the real-time residential load to follow a preplanned day-ahead energy generation by the microgrid, based on predicted customers’ aggregate load. A deviation from the predicted demand at the time of consumption is assumed to result in additional cost or penalty inflicted on the deviated customers. To develop our system, we formulate a game with mixed strategy which in the first phase (i.e., prediction phase) allows each customer to process the day ahead raw predicted demand to reduce the anticipated electricity cost by generating a flattened curve for its forecasted future demand. Then, in the second stage (i.e., allocation phase), customers play another game with mixed strategy to mitigate the deviation between the instantaneous real-time consumption and the day-ahead predicted one. To achieve this, customers exploit renewable energy and ESSs and decide optimal strategies for their charging/discharging, taking into account their operational constraints. RDCDSM will help the microgrid operator to better deal with uncertainties in the system through better planning its day-ahead electricity generation and purchase, thus increasing the quality of power delivery to the customer. We evaluate the performance of our method against a centralized allocation and an existing decentralized EV charge control noncooperative game method both of which rely on a day ahead demand prediction without any refinement. We run simulations with various microgrid configurations, by varying the load and generated power, and compare the outcomes.
Autors: Mosaddek Hossain Kamal Tushar;Adel W. Zeineddine;Chadi Assi;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 117 - 126
Publisher: IEEE
 
» Demodulation Approach for Slowly Sampled Sensorless Field-Oriented Control Systems Enabling Multiple-Frequency Injections
Abstract:
This paper describes a demodulation approach based on the least squares method for a saliency-based position estimation in slowly sampled field-oriented control systems. The proposed approach focuses on the sensorless control of electrical drives in which the sample rate of the control task chosen is slower than both the maximum possible update rate of the phase voltages and the maximum possible sample rate of the phase current measurement by a multiple. Under those conditions, it is possible to inject multiple-frequency carrier signals between two successive control sampling instances without affecting the control. Furthermore, a combined demodulation of these signals is enabled by exploiting the constant manipulated variables of the field-oriented control system during the injection sequence. With the proposed method, the signal-to-noise-ratio of the calculated rotor position as well as the acoustic noise produced by signal injections can be optimized. The approach is implemented in a field-oriented control for permanent magnet synchronous machines and is verified in experiments.
Autors: Marco Roetzer;Ulrich Vollmer;Ralph M. Kennel;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 732 - 744
Publisher: IEEE
 
» Demonstration of Constant 8 W/mm Power Density at 10, 30, and 94 GHz in State-of-the-Art Millimeter-Wave N-Polar GaN MISHEMTs
Abstract:
This paper reports on state-of-the-art millimeter-wave power performance of N-polar GaN-based metal–insulator–semiconductor high-electron-mobility transistors at 30 and 94 GHz. The performance is enabled by our N-polar deep recess structure, whereby a GaN cap layer is added in the access regions of the transistor to simultaneously enhance the access region conductivity while mitigating dc-to-RF dispersion. The impact of lateral scaling of the drain access region length is examined using the tradeoff between breakdown voltage and small-signal gain. Load-pull measurements are presented at 94 GHz, corresponding to the target device operating frequency in W-band, where the device demonstrated a peak power-added efficiency (PAE) of 28.8% at 16 V and record-high maximum output power density of 8 W/mm at 20 V. Additional load-pull measurements at 30 and 10 GHz demonstrate the viability of this device across a wide frequency range where the peak power remained constant at 8 W/mm and with peak PAEs of 56% and 58%, respectively.
Autors: Brian Romanczyk;Steven Wienecke;Matthew Guidry;Haoran Li;Elaheh Ahmadi;Xun Zheng;Stacia Keller;Umesh K. Mishra;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2018, volume: 65, issue:1, pages: 45 - 50
Publisher: IEEE
 
» Density of Spherically Embedded Stiefel and Grassmann Codes
Abstract:
The density of a code is the fraction of the coding space covered by packing balls centered around the codewords. A high density indicates that a code performs well when used as a uniform point-wise discretization of an ambient space. This paper investigates the density of codes in the complex Stiefel and Grassmann manifolds equipped with the chordal distance arising from an Euclidean embedding, including the unitary group as a special case. The choice of distance enables the treatment of the manifolds as subspaces of Euclidean hyperspheres. In this geometry, the densest packings are not necessarily equivalent to maximum–minimum-distance codes. Computing a code’s density follows from computing: 1) the normalized volume of a metric ball and 2) the kissing radius, the radius of the largest balls one can pack around the codewords without overlapping. First, the normalized volume of a metric ball is evaluated by asymptotic approximations. The volume of a small ball can be well-approximated by the volume of a locally equivalent tangential ball. In order to properly normalize this approximation, the precise volumes of the manifolds induced by their spherical embedding are computed. For larger balls, a hyperspherical cap approximation is used, which is justified by a volume comparison theorem showing that the normalized volume of a ball in the Stiefel or Grassmann manifold is asymptotically equal to the normalized volume of a ball in its embedding sphere as the dimension grows to infinity. Then, bounds on the kissing radius are derived alongside corresponding bounds on the density. Unlike spherical codes or codes in flat spaces, the kissing radius of Grassmann or Stiefel codes cannot be exactly determined from its minimum distance. It is nonetheless possible to derive bounds on density as functions of the minimum distance. Stiefel and Grassmann codes have larger density than their image spherical codes when dimensions tend to infinity- Finally, the bounds on density lead to refinements of the standard Hamming bounds for Stiefel and Grassmann codes.
Autors: Renaud-Alexandre Pitaval;Lu Wei;Olav Tirkkonen;Camilla Hollanti;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2018, volume: 64, issue:1, pages: 225 - 248
Publisher: IEEE
 
» Dependability Assessment of SOA-Based CPS With Contracts and Model-Based Fault Injection
Abstract:
Engineering complex distributed systems is challenging. Recent solutions for the development of cyber-physical systems (CPS) in industry tend to rely on architectural designs based on service orientation, where the constituent components are deployed according to their service behavior and are to be understood as loosely coupled and mostly independent. In this paper, we develop a workflow that combines contract-based and CPS model-based specifications with service orientation, and analyze the resulting model using fault injection to assess the dependability of the systems. Compositionality principles based on the contract specification help us to make the analysis practical. The presented techniques are evaluated on two case studies.
Autors: Loris Dal Lago;Orlando Ferrante;Roberto Passerone;Alberto Ferrari;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 360 - 369
Publisher: IEEE
 
» Deploying Software Team Analytics in a Multinational Organization
Abstract:
Implementing a software engineering analytics solution poses challenges and offers significant value for the globally distributed software development organization at ABB. Because software development activities in agile methodologies revolve around the team, ABB decided to implement an analytics solution focused on team metrics as part of its Software Development Improvement Program. Using key indicators focused around team improvement, researchers found that teams could manage their activities with metrics such as cycle time. Key lessons learned include paying attention to visual design and navigation and providing drill-down capabilities for the user. This article is part of a special issue on Actionable Analytics for Software Engineering.
Autors: Vinay Augustine;John Hudepohl;Przemyslaw Marcinczak;Will Snipes;
Appeared in: IEEE Software
Publication date: Jan 2018, volume: 35, issue:1, pages: 72 - 76
Publisher: IEEE
 
» Derivative-Free Kalman Filtering Based Approaches to Dynamic State Estimation for Power Systems With Unknown Inputs
Abstract:
This paper proposes a decentralized derivative-free dynamic state estimation method in the context of a power system with unknown inputs, to address cases when system linearization is cumbersome or impossible. The suggested algorithm tackles situations when several inputs, such as the excitation voltage, are characterized by uncertainty in terms of their status. The technique engages one generation unit only and its associated measurements, and it remains totally independent of other system wide measurements and parameters, facilitating in this way the applicability of this process on a decentralized basis. The robustness of the method is validated against different contingencies. The impact of parameter errors, process, and measurement noise on the unknown input estimation performance is discussed. This understanding is further supported through detailed studies in a realistic power system model.
Autors: Georgios Anagnostou;Bikash C. Pal;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 116 - 130
Publisher: IEEE
 
» Design and Analysis of a Flux Reversal Machine With Evenly Distributed Permanent Magnets
Abstract:
In this paper, a flux reversal machine (FRM), which has a larger torque density and a smoother torque waveform than the conventional FRM, is introduced. The FRM has the same combinations of stator and rotor slots, winding pole pair, and permanent magnet (PM) usage as the conventional FRM, but has different PM arrangements, i.e., in the conventional FRM, a pair of PMs is mounted on the surface of each stator teeth while the PMs of the FRM introduced in this paper are evenly distributed along the inner surface of the stator. First, the origination from the conventional FRM to the proposed FRM is introduced. Then, the effects of the rotor slot number, split ratio, stator/rotor slot opening ratio, PM thickness, and pole arc on the average torque and cogging torque are investigated and analyzed, which give a reasonable prediction for maximum achievable power density and minimum possible cogging torque of the proposed FRM. Moreover, the proposed FRM is compared with a conventional FRM in terms of back electromotive force, rated torque, pulsating torque, power factor, and overload capabilities. Finally, a 12-stator-slot/17-rotor-slot FRM prototype is built to verify the theoretical analyses.
Autors: Dawei Li;Yuting Gao;Ronghai Qu;Jian Li;Yongsheng Huo;Han Ding;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 172 - 183
Publisher: IEEE
 
» Design and Analysis of Energy-Efficient Single-Pulse Piezoelectric Energy Harvester and Power Management IC for Battery-Free Wireless Remote Switch Applications
Abstract:
This paper presents a piezoelectric-based power management solution for battery-free wireless remote switches (BWSs). The proposed BWS IC, including a piezoelectric (PE) energy harvester and a buck converter, can collect the energy generated by a single PE-button press, and then supply that energy to a wireless transmitter to send a message. By combining a rectifier using the synchronized switch harvesting on inductor technique and a 6:1 series–parallel switched-capacitor converter, the proposed PE energy harvester can maximize the collected amount of energy, while supplying it at a low output voltage. In addition, by employing a switching-based start-up scheme and a variable ON-time pulse-frequency modulation scheme, the proposed buck converter can reduce the loss associated with charging the output capacitor during start-up, and then deliver the largest possible energy to the load, while maintaining low voltage ripples and high-power efficiency. A prototype BWS IC fabricated with high-voltage 250-nm CMOS technology was shown to be capable of harvesting a total energy of from a single button-pressing of a 300-mm2 lead magnesium niobate-lead titanate PE disc. More than was delivered to the load, sufficient to transmit a 4-B-long message via a 2.4-GHz wireless USB channel over a 10-m distance.
Autors: Minbok Lee;Joonseok Yang;Myeong-Jae Park;Sung-Youb Jung;Jaeha Kim;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jan 2018, volume: 65, issue:1, pages: 366 - 379
Publisher: IEEE
 
» Design and Analysis of FTZNN Applied to the Real-Time Solution of a Nonstationary Lyapunov Equation and Tracking Control of a Wheeled Mobile Manipulator
Abstract:
The Lyapunov equation is widely employed in the engineering field to analyze stability of dynamic systems. In this paper, based on a new evolution formula, a novel finite-time recurrent neural network (termed finite-time Zhang neural network, FTZNN) is proposed and studied for solving a nonstationary Lyapunov equation. In comparison with the original Zhang neural network (ZNN) model for a nonstationary Lyapunov equation, the convergence performance has a remarkable improvement for the proposed FTZNN model and can be accelerated to finite time. Besides, by solving the differential inequality, the time upper bound of the FTZNN model is computed theoretically and analytically. Simulations are conducted and compared to validate the superiority of the FTZNN model to the original ZNN model for solving the nonstationary Lyapunov equation. At last, the FTZNN model is successfully applied to online tracking control of a wheeled mobile manipulator.
Autors: Lin Xiao;Bolin Liao;Shuai Li;Zhijun Zhang;Lei Ding;Long Jin;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 98 - 105
Publisher: IEEE
 
» Design and Analysis of W-Band Injection-Locked Frequency Divider Using Split Transformer-Coupled Oscillator Technique
Abstract:
A W-band injection-locked frequency divider (ILFD) with low-power and wide locking range is presented in this paper. The operation frequency and locking range are enhanced by using split transformer-coupled oscillator. The optimum bias and the size of the injection transistor are chosen to achieve wider locking range without increasing chip area and dc power consumption. The proposed ILFD is implemented in 90-nm CMOS and exhibits 25.4% locking range from 75.1 to 99 GHz at an input power of 0 dBm without any tuning mechanism. The core dc power consumption is 2.45 mW with a supply voltage of 0.7 V and the core chip size is mm2.
Autors: Yu-Hsuan Lin;Huei Wang;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 177 - 186
Publisher: IEEE
 
» Design and Comparison of Three-Phase and Five-Phase FTFSCW-IPM Motor Open-End Winding Drive Systems for Electric Vehicles Applications
Abstract:
This paper proposes and compares two new fault-tolerant fractional-slot concentrated-winding interior permanent magnet (FTFSCW-IPM) motor open-end winding (OW) drive systems for electric vehicles. The proposed FTFSCW-IPM motors possess the merits of high efficiency, high power density, and strong fault-tolerant capacity. Also, to further improve the reliability of control system, an OW dual inverter drive system is adopted. Furthermore, to better and clearer illustrate the advantages and disadvantages of multiphase machine system, the comprehensive comparison of three-phase and five-phase FTFSCW-IPM motor OW drive systems is carried out from the perspective of motor design and control system. The topologies and the features of the proposed two FTFSCW-IPM motors are analyzed, and the static characteristics are investigated and compared by using the finite-element analysis (FEA). Then, the evaluation of their OW drive system performance is conducted and compared by the simulation based on the MATLAB/Simulink. Finally, the FEA and simulation results are validated by experiment on both prototypes.
Autors: Li Zhang;Ying Fan;Robert D. Lorenz;Ademir Nied;Ming Cheng;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2018, volume: 67, issue:1, pages: 385 - 396
Publisher: IEEE
 
» Design and Dynamic Characterization of an Orientation Insensitive Microwave Water-Cut Sensor
Abstract:
Modern reservoir management in oil and gas industry relies on accurate water fraction measurement which is produced as a by-product with oil. This paper presents a novel and contactless water fraction (also known as water-cut) measurement technique which is independent of geometric distribution of oil and water inside the pipe. The sensor is based on a modified T-resonator implemented directly on the pipe’s outer surface and whose resonance frequency decreases by increasing the water content in oil. The E-fields have been made to rotate and distribute well inside the pipe, despite having narrow and curved ground plane. It makes the sensor’s reading dependent only on the water fraction and not on the mixture distribution inside the pipe. That is why, the presented design does not require any flow conditioner to homogenize the oil/water mixture unlike many commercial water-cut (WC) sensors. The presented sensor has been realized by using extremely low-cost methods of screen printing and reusable 3-D printed mask. Complete characterization of the proposed WC sensor, both in horizontal and vertical orientations, has been carried out in an industrial flow loop. Excellent repeatability of the sensor’s response has been observed in “dispersed bubble” as well as in “stratified wavy” flow regimes. The performance test of the sensor confirms that the water fraction measurement is independent of the flow pattern, flow rate or orientation. The measured performance results of the sensor show full range accuracy of ±2%–3% while tested under random orientations and wide range of flow rates.
Autors: Muhammad Akram Karimi;Muhammad Arsalan;Atif Shamim;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 530 - 539
Publisher: IEEE
 
» Design and Implementation of Fourth Arm for Elimination of Bearing Current in NPC-MLI-Fed Induction Motor Drive
Abstract:
The exploration result of an increase in power electronics converter-based variable-speed drives for industrial applications reveals the impact of inverter-induced bearing current on the prevailing electric machine failure. The bearing current associated with drive systems is concerned about operating frequencies of the solid-state semiconductor switches, which may cause the electrostatic charge between stator and rotor, which eventually causes damage to windings and bearings. The various techniques comprised in the literature to suppress bearing currents are filter design, switching redundancy, common-mode circuitry, isolated grounding scheme, and grounding the motor shaft. From the literature, the pulse-width modulation inverter-injected common-mode voltage (CMV) is the main source of common-mode current, which causes the bearing current. Hence, the elimination of CMV paves the way for eliminating bearing current of the machine. This paper presents an innovative solution to suppress bearing currents by aiding a fourth arm circuitry to acquire near to zero potential (zero CMV) at machine neutral point. All the proposed circuitry and algorithm are simulated using MATLAB/Simulink and validation is done through a 2.5-kW neutral-point-clamped-multilevel inverter laboratory prototype using a Xilinx family SPARTAN-III-3A XC3SD1800A-FG676 digital signal processor-field programmable gate array board.
Autors: C. Bharatiraja;Raghu Selvaraj;Thanga Raj Chelliah;Josiah L. Munda;Mohd Tariq;Ali I. Maswood;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 745 - 754
Publisher: IEEE
 
» Design and Multiplierless Realization of Maximally Flat Sharpened-CIC Compensators
Abstract:
Polynomial sharpening is an efficient technique for improving folding band response of cascaded-integrator-comb (CIC) decimation filters. However, the sharpening of folding bands results in a high passband droop, which is intolerable in many applications. The droop can be reduced by connecting a symmetric finite-impulse-response filter called compensator in the cascade with the sharpened CIC (SCIC) filter. This brief presents a method for the design of such compensators, which is based on maximally flat error criterion. The compensator’s coefficients are obtained by solving a linear system of equations which is formed using a straightforward procedure. The coefficients obtained generally take real values. However, we show that for the SCIC filters incorporating integer or sum of powers of two (SPT) polynomial coefficients, and whose decimation factors are expressed as powers of two, the coefficients of corresponding maximally flat compensators are integers or SPT representable. For these types of SCIC filters, the optimum multiplierless structures of the compensators with three and five coefficients are described.
Autors: Goran Molnar;Aljosa Dudarin;Mladen Vucic;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2018, volume: 65, issue:1, pages: 51 - 55
Publisher: IEEE
 
» Design and Optimization for Vehicle Driving Cycle of Rare-Earth-Free SynRM Based on Coupled Lumped Thermal and Magnetic Networks
Abstract:
This study presents a range optimization of a synchronous reluctance motor and a permanent-magnet-assisted synchronous reluctance motor according to a standard driving cycle, and the solutions obtained are compared. The proposed approach avoids the use of a finite-element analysis during the optimization process, thus greatly reducing the time required to obtain the optimal solution. This paper validates the optimal motors obtained in different domains, since the methodology takes into account a multiphysics design. Using two coupled reluctance and thermal networks, all possible working points in the torque–speed plane are obtained taking into account thermal effects, magnetic saturation, iron losses, as well as voltage and current constraints imposed by the inverter. The proposed approach allows a fast comparison of the solutions attained. The design and optimization methodology presented in this study can be applied to any driving cycle.
Autors: Carlos López-Torres;Antonio Garcia Espinosa;Jordi-Roger Riba;Luis Romeral;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2018, volume: 67, issue:1, pages: 196 - 205
Publisher: IEEE
 
» Design and Optimization of SIW Center-Fed Series Rectangular Dielectric Resonator Antenna Array With 45° Linear Polarization
Abstract:
The modeling, design, and optimization of a new substrate integrated waveguide middle-fed series rectangular dielectric resonator antenna array with 45° linear polarization are presented. The implicit space mapping technique is applied for the optimization of the antenna array. A tunable circuit model is built, which serves as the coarse/surrogate mode, and a full-wave solver is used as the fine model. High design and optimization efficiency is demonstrated using an eight-element array. The reflection coefficient of the array antenna is optimized with only two iterations. The experimental data for the eight elements antenna array, operating at the millimeter-wave band (34–36 GHz), are used for the validation of both performance of the design and modeling techniques. The measured radiation pattern demonstrates a broadside beam with a maximum radiated gain of 13.55 dB over an operating impedance bandwidth of 2.2 GHz.
Autors: Mona S. Abdallah;Ying Wang;Wael M. Abdel-Wahab;Safieddin Safavi-Naeini;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 23 - 31
Publisher: IEEE
 
» Design and Optimization of VoD Schemes With Client Caching in Wireless Multicast Networks
Abstract:
Due to the explosive growth in multimedia traffic, the scalability of video-on-demand (VoD) services has become increasingly important. By exploiting the potential cache ability at the client side, the performance of VoD multicast delivery can be improved through video segment precaching. In this paper, we address the performance limits of client-caching-enabled VoD schemes in wireless multicast networks with asynchronous requests. Both reactive and proactive systems are investigated. Specifically, for the reactive system where videos are transmitted on demand, we propose a joint cache allocation and multicast delivery scheme to minimize the average bandwidth consumption under the zero-delay constraint. For the proactive system where videos are periodically broadcasted, a joint design of the cache-bandwidth allocation algorithm and the delivery mechanism is developed to minimize the average waiting time under the total bandwidth constraint. In addition to the full access pattern where clients view videos in their entirety, we further consider the access patterns with random endpoints, fixed-size intervals, and downloading demand, respectively. The impacts of different access patterns on the resource-allocation algorithm and the delivery mechanism are elaborated. Simulation results validate the accuracy of the analytical results and also provide useful insights in designing VoD networks with client caching.
Autors: Hao Feng;Zhiyong Chen;Hui Liu;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2018, volume: 67, issue:1, pages: 765 - 780
Publisher: IEEE
 
» Design and Performance Analysis of Three-Phase Solar PV Integrated UPQC
Abstract:
This paper deals with the design and performance analysis of a three-phase single stage solar photovoltaic integrated unified power quality conditioner (PV-UPQC). The PV-UPQC consists of a shunt and series-connected voltage compensators connected back-to-back with common dc-link. The shunt compensator performs the dual function of extracting power from PV array apart from compensating for load current harmonics. An improved synchronous reference frame control based on moving average filter is used for extraction of load active current component for improved performance of the PV-UPQC. The series compensator compensates for the grid side power quality problems such as grid voltage sags/swells. The compensator injects voltage in-phase/out of phase with point of common coupling (PCC) voltage during sag and swell conditions, respectively. The proposed system combines both the benefits of clean energy generation along with improving power quality. The steady state and dynamic performance of the system are evaluated by simulating in MATLAB-Simulink under a nonlinear load. The system performance is then verified using a scaled down laboratory prototype under a number of disturbances such as load unbalancing, PCC voltage sags/swells, and irradiation variation.
Autors: Sachin Devassy;Bhim Singh;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 73 - 81
Publisher: IEEE
 
» Design and Simulations of Ge2Sb2Te5 Vertical Photodetector for Silicon Photonic Platform
Abstract:
Here, we report design and simulations of a vertical photodetector based on amorphous Ge2Sb2Te5 (-GST) for silicon platform at telecommunication wavelength (1550 nm). In our investigations, it is found that -GST on silicon platform can be used as a waveguide photodetector with good responsivity and low dark current. Optimization of the structure is done to improve absorption, photocurrent, and corresponding electrical current at cathode. Our investigations reveal that ~150 nm is optimized thickness of -GST material for high responsivity (~48 A/W) when integrated on top of a single-mode silicon-on-insulator waveguide. This responsivity is comparable with existing avalanche photodiodes. With optimized dimensions, a good ratio of photocurrent to dark current is obtained. To the best of our knowledge, this is the first report on -GST-based photodetector.
Autors: Vibhu Srivastava;Manoj Tolani; Sunny;Rajesh Kumar;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 540 - 546
Publisher: IEEE
 
» Design and Testing of Novel Airborne Atmospheric Sensor Nodes
Abstract:
The design and test results are presented for a novel in situ atmospheric probe, called an environmental mote or eMote. This lightweight airborne atmospheric sensing mote has been designed for mass deployment over weather events of interest as part of a system known as GlobalSense, which aims to provide weather data with high spatial and temporal density. This letter describes the initial eMote design and ground-based test results of meteorological sensing functions. Future work to improve upon the system and move toward large-scale testing is outlined.
Autors: Michael Bolt;J. Craig Prather;Haley Harrell;Tyler Horton;John Manobianco;Mark L. Adams;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Jan 2018, volume: 15, issue:1, pages: 73 - 77
Publisher: IEEE
 
» Design and Tuning of Robust Fractional Order Controller for Autonomous Microgrid VSC System
Abstract:
A robust controller design for the voltage control of an autonomous three-phase voltage source converter (VSC) is proposed. As compared with the conventional proportional plus integral (PI) controllers, fractional order controllers make the VSC system robust due to their fractional characteristics. The fractional PI controller has an additional degree of freedom along with and gains of the conventional PI controller. Detailed modeling of a VSC is used in the controller design process so as it include inner current control and filter dynamics. The outer fractional voltage controller is designed such that the VSC system satisfies a required phase margin, with improved robustness in the system and capability to attenuate the noise. The overall system stability is analyzed using both bode plot and step response, and these responses are compared with a conventional PI controller. Further, the dynamic performance of the fractional controller is evaluated by simulating the nonlinear system. A hardware prototype is also developed to demonstrate the practical realization of the controller.
Autors: Deepak Pullaguram;Sukumar Mishra;Nilanjan Senroy;Monish Mukherjee;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 91 - 101
Publisher: IEEE
 
» Design of a Broadband Polarization-Reconfigurable Fabry–Perot Resonator Antenna
Abstract:
In this letter, a broadband polarization-reconfigurable Fabry–Perot (FP) resonator antenna is presented for WLAN/WiMAX applications. The open air-filled FP cavity is constructed by a partially reflective surface (PRS) layer directly placed over a fully reflective ground plane. A two-element patch array is employed to serve as a feeder. To achieve polarization reconfigurability, the feeding antenna is designed to have the capability of switching between horizontal linear polarization (HP) and vertical linear polarization (VP) by controlling the on/off states of four pairs of p-i-n diodes. By combining the frequency resonances of the FP cavity and the feeding antenna, the proposed FP resonator antenna obtains broadband performance. Furthermore, the proposed antenna achieves a broadband 3 dB gain bandwidth by designing the PRS layer to have a reflection phase with positive slope over as wide a frequency band as possible. The proposed antenna was fabricated and experimentally characterized. Measurements demonstrate that it achieves a −10 dB impedance bandwidth of 21 ranging from 2.2 to 2.72 GHz, which can well cover WLAN/WiMAX band of operation. The 3 dB gain bandwidths of 12.5 and 14.6 are obtained with peak realized gains of 15.1 and 14.8 dBi for the HP and VP, respectively.
Autors: Ruina Lian;Zhaoyang Tang;Yingzeng Yin;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Jan 2018, volume: 17, issue:1, pages: 122 - 125
Publisher: IEEE
 
» Design of a Dual-Mode Balun Bandpass Filter With High Selectivity
Abstract:
In this letter, a new dual-mode balun bandpass filter (BPF) with high selectivity is proposed. The balun BPF is mainly composed of two different types of microstrip-to-slotline transition structures, two identical dual-mode stub-loaded resonators, and a pair of balanced outputs. First, to convert unbalanced signals from port 1 into balanced signals between port 2 and port 3, two different types of microstrip-to-slotline transition structures are utilized. Afterward, two identical stub-loaded resonators are embedded in the circuit for realizing the dual-mode bandpass response. Furthermore, four transmission zeros generated outside the passband are wisely introduced and well elucidated, thus ensuring high selectivity performance. For demonstration, a sample of balun BPF centered at 2.78 GHz ( with 0.5-dB magnitude imbalance and 5° phase imbalance is designed, fabricated, and measured. Both simulation and measurement are in good agreements.
Autors: Haiyan Xu;Jianpeng Wang;Lei Zhu;Feng Huang;Wen Wu;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2018, volume: 28, issue:1, pages: 22 - 24
Publisher: IEEE
 
» Design of a High Extinction Ratio Tunable Graphene on White Graphene Polarizer
Abstract:
A thermally/electrically tunable graphene on white graphene polarizer is proposed, in which the resonant coupling between the plasmonic surface modes of the structure and the transverse electric (TE) [or transverse magnetic (TM)] polarized incident wave is used to absorb this polarization, while the TM (or TE) polarized incident wave is totally reflected. It is then shown that the thermal and electrical tunability of surface conductivity of graphene can be used to control the optical properties of the proposed polarizer, including the selection of the desired polarization, and adjusting the amplitude of the reflected (desired) polarization. The application of the hexagonal boron-nitride (white graphene) as the substrate of graphene increases the propagation of the surface waves of the structure, which in turn results in the very high polarization extinction ratio of 75 dB. Moreover, the ultra-small insertion loss of 0.022 dB and relatively large bandwidth of ~ 60 nm are calculated for the proposed polarizer.
Autors: Ali Farmani;Mehdi Miri;Mohammad Hossein Sheikhi;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2018, volume: 30, issue:2, pages: 153 - 156
Publisher: IEEE
 
» Design of a Notched-Band Vivaldi Antenna With High Selectivity
Abstract:
In this letter, a notched-band Vivaldi antenna with high-frequency selectivity is designed and investigated. To obtain two notched poles inside the stopband, an open-circuited half-wavelength resonator and a short-circuited stepped impedance resonator are properly introduced into the traditional Vivaldi antenna. By theoretically calculating the resonant frequencies of the two loaded resonators, the frequency locations of the two notched poles can be precisely determined, thus achieving a wideband antenna with a desired notched band. To validate the feasibility of this new approach, a notched band antenna with a fractional bandwidth of 145.8% is fabricated and tested. Results indicate that good frequency selectivity of the notched band from 4.9 to 6.6 GHz is realized, and the antenna exhibits good impedance match, high radiation gain, and excellent radiation directivity in the passband. Both the simulation and measurement results are provided with good agreement.
Autors: Yanhui Xu;Jianpeng Wang;Lei Ge;Xuedao Wang;Wen Wu;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Jan 2018, volume: 17, issue:1, pages: 62 - 65
Publisher: IEEE
 
» Design of a Vivaldi-Fed Hybrid Horn Antenna for Low-Frequency Gain Enhancement
Abstract:
This communication proposes the hybrid Vivaldi-fed horn antenna, which consists of the printed antipodal Vivaldi antenna (AVA) on an FR4 substrate for better matching performance in the low-frequency band and the horn antenna that surrounds the exterior of the AVA for increased gain performance in the high frequency. In order to verify the operating principle in the low-frequency band, an equivalent circuit of the proposed antenna is modeled and analyzed. The mode decomposition technique is then used to examine the radiation physics of the proposed antenna in high-frequency band. The measured reflection coefficients in the entire frequency range are less than −3 dB of the half-power reference (maximum of −4.11 dB). The measured gains of 2.12 dBi at 1 GHz and 7.84 dBi at 6 GHz are obtained. These results confirm that the better characteristics in low-frequency matching and high-frequency gain can be achieved by the proposed design.
Autors: Tae Heung Lim;Jong-Eon Park;Hosung Choo;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 438 - 443
Publisher: IEEE
 
» Design of Application-Specific Architectures for Networked Labs-on-Chips
Abstract:
Labs-on-Chips (LoCs) implement laboratory procedures on a single chip and are successfully used for chemical and biomedical applications. A promising and emerging realization of such chips are Networked LoCs (NLoCs) in which small volumes of fluids, so-called droplets, flow in closed channels of submillimeter diameters. NLoCs allow for an incubation and storage of assays over a long period of time and, hence, avoid evaporation and unwanted reactions. To increase the flexibility, effectiveness, and reusability, network functionalities allow to passively route droplets in channels and, hence, to dynamically select operations depending on the executed experiment. However, only manually designed architectures are considered for NLoCs thus far. They frequently suffer from large execution times and/or a high contamination of channels. To overcome these drawbacks, we propose the consideration of application-specific architectures for NLoCs. To this end, an automatic design method is proposed which, for a given set of experiments as well as constraints and objectives from the designer, is able to generate an optimized NLoC architecture realizing these experiments. Evaluations and case studies demonstrate the potential of the proposed solution for design exploration. Moreover, we are able to show that application-specific architectures are capable of realizing experiments in just a fraction of the time needed by architectures used thus far as well as with a substantially reduced contamination.
Autors: Andreas Grimmer;Werner Haselmayr;Andreas Springer;Robert Wille;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jan 2018, volume: 37, issue:1, pages: 193 - 202
Publisher: IEEE
 
» Design of Dual-Loaded RFID Tag for Higher Order Modulations
Abstract:
A touchstone for selecting two scattering states for scalar differential backscattering in passive scatterers was introduced by Green in 1963. According to this model, a scatterer has one global minimum and one global maximum scattering states on its plane. The variation of radar cross section (RCS) of the scatterer between these two states is monotonic. Thus, to achieve to the highest differential backscattering the scatterer should switch between these two states. In this paper, we verify, by measurements and simulations, that a linear half-wave dipole antenna behaves as predicted by the Green model. However, we show that the RCS of a T-match bow tie antenna over its plane cannot be modeled by the Green model and instead the antenna has two maximum scattering states on its plane. In the next step, we use dual loading on the T-match bowtie antenna structure. By appropriate selection of the loads, the antenna can provide various scattering states with various magnitudes in 360° phase span in its in-phase and quadrature plane. This feature of the proposed antenna can be used to increase the modulation depth up to 170%, provide a quasi-32-quasi-quadrature amplitude shift keying, and increase the coverage range in backscattering links.
Autors: Shadi Ebrahimi-Asl;Mohammad Tayeb Ghasr;Maciej J. Zawodniok;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 410 - 419
Publisher: IEEE
 
» Design of Five-Way Bagley Polygon Power Dividers in Rectangular Waveguide
Abstract:
Power combiners are in general complex to manufacture and do not show a compact structure when more than two output ports are needed. To overcome these problems, the design of a five-way Bagley polygon in rectangular waveguide is presented. The proposed geometry is simple, suitable for an efficient optimization, and allows its fabrication by milling. A five-way Ku-band -plane rectangular waveguide Bagley polygon for a 17% fractional bandwidth is designed, manufactured, and measured. The measured results show return loss better than 28 dB and amplitude and phase imbalances below ±0.2 dB and ±5°, respectively, which, along with the waveguide low losses, leads to a 98% efficiency as power combiner.
Autors: Ana Buesa-Zubiria;Jaime Esteban;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 116 - 127
Publisher: IEEE
 
» Design of Frequency Selective Surface Structure With High Angular Stability for Radome Application
Abstract:
A design method for frequency selective surface (FSS) structure with high angular stability has been proposed in this letter. In the proposed method, bandwidth angular stability of FSS structure has been improved by adopting the bandwidth compensation technique, and structural parameters can be obtained with a curve-fitting method from the desired resonate frequency and bandwidth. Discussions on improving the bandwidth design accuracy have been presented. By taking bandwidth angular stability into consideration, the structure designed by the proposed method is more suitable to construct FSS radome. For verification, an FSS structure operating at 15 GHz with a bandwidth of 2 GHz has been designed, fabricated, and measured. Good agreements between the simulated and measured results can be observed.
Autors: Ning Liu;Xianjun Sheng;Chunbo Zhang;Dongming Guo;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Jan 2018, volume: 17, issue:1, pages: 138 - 141
Publisher: IEEE
 
» Design of Frequency-and Polarization-Reconfigurable Antenna Based on the Polarization Conversion Metasurface
Abstract:
A frequency- and polarization-reconfigurable antenna composed of a metasurface, a planar slot antenna, and a metallic reflector is proposed in this letter. The metasurface is made up of 64 identical patches, and all the patches are on the top surface of the substrate. In order to extend the bandwidth of the antenna, the planar slot antenna adopts a double-slot structure. The reconfiguration of frequency and polarization can be achieved by adjusting the relative positions between the metasurface and the planar slot antenna. The antenna can be reconfigured to linear polarization, and left-hand and right-hand circular polarizations. At the same time, the gain of the antenna is improved. In order to verify this method, a frequency- and polarization-reconfigurable antenna is designed. Simulation and experimental results show that the polarization reconfiguration can be achieved from 8 to 11.2 GHz (fractional bandwidth of 33.33%) by adjusting the distance among the metasurface, source antenna, and metallic reflector. The maximum gain can achieve 16.5 dBi.
Autors: Chun Ni;Ming Sheng Chen;Zhong Xiang Zhang;Xian Liang Wu;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Jan 2018, volume: 17, issue:1, pages: 78 - 81
Publisher: IEEE
 
» Design of GaN-Based Multicolor Tunnel-Junction Light-Emitting Diodes
Abstract:
The design of monolithic multicolor tunnel-junction (TJ) light-emitting diodes (LEDs) are investigated numerically. This paper primarily aims to design and study monolithic TJ LED devices that possess high luminous efficiency and wide color gamut using a simple fabrication process. First, the characteristics of green and blue single LEDs are explored. Nonuniform carrier distribution inside quantum wells (QWs), which is due to the deep QWs and severe polarization effect, is observed for both single LEDs under study. Based on structural analysis of the single LEDs, streamline dual-color and broadband TJ LED structures, in which the blue unit LED has two pairs of 3-nm-thick QWs and the green unit LED has 3-nm-thick single QW, are designed and investigated. Specifically, monolithic dual-color blue/green (459/530 nm) TJ LED is proposed and analyzed using effective n+-GaN/i-In0.2 Ga0.8N/p+-GaN TJ. Furthermore, broadband TJ LED with simulated full width at half maximum of around 100 nm is achieved.
Autors: Ya-Hsuan Shih;Jih-Yuan Chang;Yen-Kuang Kuo;Fang-Ming Chen;Man-Fang Huang;Ming-Lun Lee;Jinn-Kong Sheu;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2018, volume: 65, issue:1, pages: 165 - 171
Publisher: IEEE
 
» Design of Low-Power Low-Area Tunable Active RC Filters
Abstract:
A method to design low-power low-area active RC filters is presented. The output voltages of the operational amplifiers are scaled and buffered, allowing the use of single stage topologies for less power consumption and eliminating the compensation capacitor. Tuning of the filter characteristic is also done by switching the currents through the output buffers, which removes the need for capacitor banks. The advantages of the proposed method are incorporated to present a general low-power biquad with small die area. The biquad section is then used to design a low-power baseband filter for Bluetooth receivers with 600-KHz cutoff frequency. The fourth-order filter, fabricated in a 0.18- CMOS process, consumes 0.5 mW with a die area of 0.13 mm.
Autors: Amirhossein Rasekh;M. Sharif Bakhtiar;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2018, volume: 65, issue:1, pages: 6 - 10
Publisher: IEEE
 
» Design of Scalable Hardware-Efficient Compressive Sensing Image Sensors
Abstract:
This paper presents a new compressive sensing (CS) measurement method for image sensors, which limits pixel summation within neighbor pixels and follows regular summation patterns. Simulations with a large set of benchmark images show that the proposed method leads to improved image quality. Circuit implementation for the proposed CS measurement method is presented with the use of current mode pixel cells; and the resultant CS image sensor circuit is significantly simpler than existing designs. With compression rates of 4 and 8, the developed CS image sensors can achieve 34.2- and 29.6-dB PSNR values with energy consumption of 1.4 and 0.73 per frame, respectively.
Autors: Stefan Leitner;Haibo Wang;Spyros Tragoudas;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 641 - 651
Publisher: IEEE
 
» Design of Sparse Halbach Magnet Arrays for Portable MRI Using a Genetic Algorithm
Abstract:
Permanent magnet arrays offer several attributes attractive for the development of a low-cost portable MRI scanner for brain imaging. They offer the potential for a relatively lightweight, low to mid-field system with no cryogenics, a small fringe field, and no electrical power requirements or heat dissipation needs. The cylindrical Halbach array, however, requires external shimming or mechanical adjustments to produce B0 fields with standard MRI homogeneity levels (e.g., 0.1 ppm over field of view), particularly when constrained or truncated geometries are needed, such as a head-only magnet where the magnet length is constrained by the shoulders. For portable scanners using rotation of the magnet for spatial encoding with generalized projections, the spatial pattern of the field is important since it acts as the encoding field. In either a static or rotating magnet, it will be important to be able to optimize the field pattern of cylindrical Halbach arrays in a way that retains construction simplicity. To achieve this, we present a method for designing an optimized cylindrical Halbach magnet using the genetic algorithm (GA) to achieve either homogeneity (for standard MRI applications) or a favorable spatial encoding field pattern (for rotational spatial encoding applications). We compare the chosen designs against a standard, fully populated sparse Halbach design, and evaluate optimized spatial encoding fields using point-spread-function and image simulations. We validate the calculations by comparing to the measured field of a constructed magnet. The experimentally implemented design produced fields in good agreement with the predicted fields, and the GA was successful in improving the chosen metrics. For the uniform target field, an order of magnitude homogeneity improvement was achieved compared to the un-optimized, fully populated design. For the rotational encoding design, the resolution uniformity is improved by 95% compared to - uniformly populated design.
Autors: Clarissa Zimmerman Cooley;Melissa W. Haskell;Stephen F. Cauley;Charlotte Sappo;Cristen D. Lapierre;Christopher G. Ha;Jason P. Stockmann;Lawrence L. Wald;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2018, volume: 54, issue:1, pages: 1 - 12
Publisher: IEEE
 
» Design of TE-Polarized Bessel Antenna in Microwave Range Using Leaky-Wave Modes
Abstract:
In this paper, we present a transverse electric (TE)-polarized Bessel-beam antenna in the microwave range based on a leaky radial waveguide. According to the dispersion equation, an inductive sheet over a ground plane is needed. To achieve the inductive sheet, a grid structure printed on a dielectric substrate is designed. Besides, the radial waveguide is coaxially fed with a quasi-loop shaped structure to excite TE mode. The proposed antenna is investigated by simulation and measurement. In the measurement, a small loop is used to probe near magnetic field, and accurate measured magnetic intensity profiles are presented. The measurements show that TE-polarized Bessel beams can be launched within the nondiffractive range of 145 mm () at 5.8 GHz.
Autors: Ping Lu;Damien Voyer;Arnaud Bréard;Julien Huillery;Bruno Allard;Xuefang Lin-Shi;Xue-Song Yang;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 32 - 41
Publisher: IEEE
 
» Design of Vector Field for Different Subphases of Gait and Regeneration of Gait Pattern
Abstract:
In this paper, we have designed the vector fields (VFs) for all the six joints (hip, knee, and ankle) of a bipedal walking model. The bipedal gait is the manifestation of temporal changes in the six joints angles, two each for hip, knee, and ankle values and it is a combination of seven different discrete subphases. Developing the correct joint trajectories for all the six joints was difficult from a purely mechanics-based model due to its inherent complexities. To get the correct and exact joint trajectories, it is very essential for a modern bipedal robot to walk stably. By designing the VF correctly, we are able to get the stable joint trajectory ranges and able to reproduce angle ranges from theses designed VFs. This is purely a data driven computational modeling approach, which is based on the hypothesis that morphologically similar structure (human-robot) can adopt similar gait patterns. To validate the correctness of the design, we have applied all the possible combination of joint trajectories to HOAP-2 bipedal robot, which could walk successfully maintaining its stability. The VF provides joint trajectories for a particular joint. The results show that our data driven computational model is able to provide the correct joints angle ranges, which are stable.

Note to Practitioners—In this research, we have developed the vector field (VF) for each joint (hip, knee, and ankle) of a biped, which plays an important role in walking. The idea is noble and based on data driven computational model. The generated trajectories are applied on HOAP-2 bipedal humanoid robot and compare the two joint trajectories from VF with HOAP-2 model and hybrid automata model.

Autors: Vijay Bhaskar Semwal;Chandan Kumar;Piyush Kumar Mishra;Gora Chand Nandi;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2018, volume: 15, issue:1, pages: 104 - 110
Publisher: IEEE
 
» Design of Wideband Circularly Polarized Antenna Using Coupled Rotated Vertical Metallic Plates
Abstract:
A simple structure composed of four rotated metallic plates is proposed to enhance the bandwidth of circularly polarized (CP) crossed-dipole antenna. The metallic plates are vertically added on the ground plane in a sequential rotation way, surrounding the primary radiator of the crossed-dipole antenna. Owing to the coupling with the radiator, orthogonal currents can be induced on the metallic plates. Additional impedance and axial ratio passbands can, therefore, be generated beside the original operating band, enhancing its bandwidth substantially. As the metallic plates are mounted on the ground plane, no extra footprint is needed, making the area of the wideband antenna very compact. Simulation and measured results show that by using this simple structure, the operating bandwidth of CP crossed-dipole antenna can be enhanced significantly from ~30% to 106.1%. The structure is also applicable to the intrinsically narrowband patch antennas.
Autors: Yong Mei Pan;Wan Jun Yang;Shao Yong Zheng;Peng Fei Hu;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 42 - 49
Publisher: IEEE
 
» Design Optimization of a High-Speed Synchronous Reluctance Machine
Abstract:
Synchronous reluctance machines, including the permanent-magnet-assisted variants, are competitive motor topologies if the application requires high efficiency and a cost-effective solution with a high flux-weakening capability. However, increasing operating speeds incur challenging design and development decisions, mainly in order to find design solutions that ensure the machine's structural integrity without compromising the overall performance. In this paper, a comprehensive design procedure for high-speed synchronous reluctance machines is presented. In order to validate the procedure, a 5-kW 80 000-r/min machine is considered. The proposed strategy consists of a two-step procedure in which the electromagnetic and structural designs have been properly decoupled, dividing the design space in two subsets. Each subset mainly affects the electromagnetic or the structural performances. Several structural design optimizations have been then performed with the aim of finding the optimal tradeoff between the rotor geometrical complexity (that defines the required computational resources) and the electromagnetic performance. The reported experimental tests of the prototyped machine validate the proposed design strategy, which can be used as general guidelines on the structural design of synchronous reluctance machines.
Autors: Mauro Di Nardo;Giovanni Lo Calzo;Michael Galea;Chris Gerada;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 233 - 243
Publisher: IEEE
 
» Design Techniques for Signal Reflection Suppression in High-Speed 25-Gb/s Laser Drivers in CMOS
Abstract:
In this letter, we propose design techniques to suppress high-speed signal reflections observed in direct-modulated laser drivers. The first technique utilizes active back-termination (ABT) to absorb the reflected energy from the laser impedance mismatch. In the second design, capacitively coupled pre-emphasis (CCPE) is proposed to cancel the transient over-shooting observed from the bond-wire reflections. In order to evaluate these techniques, the two 25-Gb/s CMOS laser drivers are designed and fabricated in a standard 65-nm process. Experimental results show that both drivers exhibit clear 25.78-Gb/s optical eye-diagrams with >4 dB extinction ration, and also exhibit significant improvement in jitter performance when the ABT or CCPE is enabled.
Autors: Jingbo Shi;Bozhi Yin;Nan Qi;Rui Bai;Zhiyong Li;Zhiliang Hong;Patrick Yin Chiang;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2018, volume: 30, issue:1, pages: 39 - 42
Publisher: IEEE
 
» Design, Fabrication, and Characterization of a Low-Temperature Curable Magnetic Composite for Power Electronics Integration
Abstract:
To simplify the integration process of embedding magnetic components in power electronics converters, we fabricated a magnetic-filled-benzocyclobutene composite that can be cured at temperatures below 250 °C without pressure. The magnetic fillers used in the formulation were a round-shaped particle of permalloy and a flake-shaped particle of Metglas 2705 M. To guide the formulation, we first constructed 3-D finite-element models of the composite consisting of periodic unit cells of magnetic particles and flakes in the polymer matrix and used Ansoft Maxwell to simulate magnetic properties of the composite. Then, flowable pastes of the composite with varying amounts of Metglas in the magnetic fillers up to 12.5 wt% were prepared, and toroid cores were poured and cured at 250 °C. Subsequently, magnetic properties of the cores, i.e., complex permeability and core loss density, were measured. We found that the real part of the composite’s relative permeability increased with Metglas addition, reaching a value of 26 at 12.5%. However, the core loss data at 1 and 5 MHz showed that the addition of Metglas flakes also increased the core loss density. The measured properties were consistent with the Maxwell simulation results. Microstructures of the cores were examined by scanning electron microscopy. We found that the magnetic particles were uniformly dispersed and isolated by the polymer, which explained the high electrical resistivities of the composite and relatively low core loss densities due to suppression of inter-particle eddy-current losses.
Autors: Yi Yan;Weizhen Sun;Shan Gao;Ting Ge;Khai D. T. Ngo;Guo-Quan Lu;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2018, volume: 54, issue:1, pages: 1 - 6
Publisher: IEEE
 
» Detecting Flooding Attack and Accommodating Burst Traffic in Delay-Tolerant Networks
Abstract:
Delay-tolerant network (DTN) is developed to cope with intermittent connectivity and long delay in wireless networks. Due to limited connectivity, DTN is vulnerable to flooding attack in which malicious nodes flood the network with superfluous data to deplete the network resources. Existing works mitigate internal flooding attacks by rate limit to constrain the number of messages that nodes can generate per time slot. However, rate limit cannot flexibly accommodate burst traffic in which nodes may have sending demands higher than the rate limit for a short period. In this paper, we propose flooding detection based on encounter records (FDER) to detect flooding attack and yet allow legitimate burst traffic simultaneously. Nodes exchange their histories of encounter records (ER), which record the sent messages during their previous encounters. The ER history is used to infer a node's new message transmission rate over time and the number of forwarded replicas per message. The adversary nodes that send too many messages or replicas can thus be detected. Since ERs serve as useful tools for monitoring the sending behavior of nodes over a long time period, FDER could detect the burst traffic violation efficiently. We also design fairness policy (FP)—a fairness forwarding policy to ensure fairness in the delivery performance fairness between nodes with normal traffic and those with burst traffic. FP uses ER information to observe nodes’ rate of new message generation and adjust their forwarding priorities accordingly. Simulation results show that FDER can detect flooding attack at a higher accuracy and a lower delay compared to a state-of-the-art scheme with affordable overhead. Moreover, FP could mitigate the smart flooding attack and still provide the performance fairness to support bursty traffic scenario.
Autors: Thi Ngoc Diep Pham;Chai Kiat Yeo;Naoto Yanai;Toru Fujiwara;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2018, volume: 67, issue:1, pages: 795 - 808
Publisher: IEEE
 
» Detection of an Intruder and Prediction of His State of Motion by Using Seismic Sensor
Abstract:
Detection of intruders and predicting their activities are the first and foremost needs of surveillance. An embedded system employing geophone, adaptive event extraction, and robust machine learning algorithms have made it possible not only to detect the presence of a potentially harmful intruder but also to predict to a high degree of accuracy, his state of motion, and to take counter action at the earliest. This paper aims to be an in-depth study of this simple yet effective technique of intruder detection and its subsequent predictive analysis of motion which should come as a handy aid to security solutions all-around. The proposed event extraction technique detects footfall events and extracts portions of the signal that correspond to an event. Using the classifier SVM-RBF and the proposed event extraction technique the presence of an intruder can be predicted with an accuracy of 86% from a signal of length 2 s and its state of motion with an accuracy of 77% from a signal of length 6 s.
Autors: Bodhibrata Mukhopadhyay;Sahil Anchal;Subrat Kar;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 703 - 712
Publisher: IEEE
 
» Detection of Digitally Phase-Modulated Signals Utilizing Mechanical Vibration of CNT Cantilever
Abstract:
Communication between tiny sensor nodes is an important function in future sensing applications and services. This paper contributes to the design of both the front end and the demodulator of nanoscale receivers. A nanoscale phase detector is proposed that provides two important functions at nanoscale: reception of an incoming carrier signal in the megahertz band, and detection of the carrier phase which contains the information of the transmitted digital data. These two functions are achieved by the mechanical vibration of the tip of a carbon nanotube. The proposed detector was theoretically analyzed in terms of its communication aspects; although a digitally phase-modulated signal could be detected in nanoscale, the effective received signal power showed to be strongly reduced in a key performance measure in communication systems, bit error rate. However, the present analysis reveals that the output of the proposed detector has two frequency components, which describe the transmitted data. To take the advantage of this characteristic, a demodulator using maximum-ratio combining is introduced in this paper. The optimal weights used to combine the components were analytically derived to improve the bit error rate performance. The effectiveness of the nanoscale phase detector is numerically demonstrated, and the gain relative to the demodulation achieved using a conventional simple correlator is established.
Autors: Yukihiro Tadokoro;Yutaka Ohno;Hiroya Tanaka;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jan 2018, volume: 17, issue:1, pages: 84 - 92
Publisher: IEEE
 
» Detection of Orbital Angular Momentum With Metasurface at Microwave Band
Abstract:
An orbital angular momentum (OAM) detection approach at microwave band is proposed. A transmittance function is exploited to model a transmissive metasurface. Then, the metasurface is designed to convert an OAM wave to multiple waves, only one of which is Gaussian. The radiation direction of the Gaussian wave is distinguishable according to the order of incident OAM. Consequently, by locating the Gaussian wave, the incident OAM can be conveniently determined. We use a simple field source to simulate the incident OAM wave in full-wave simulation. It largely simplifies the simulation process when an incident wave carrying OAM is needed. Both numerical and full-wave simulation results are provided to validate our design, and they show good agreement with each other. Then, the metasurface is optimized for high directivity. Our work can provide an efficient and effective way for OAM detection in radio communications.
Autors: Menglin L. N. Chen;Li Jun Jiang;Wei E. I. Sha;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Jan 2018, volume: 17, issue:1, pages: 110 - 113
Publisher: IEEE
 
» Detection of Root Orientation Using Ground-Penetrating Radar
Abstract:
Due to its in situ and nondestructive nature, ground-penetrating radar (GPR) has recently been applied to the field investigation of plant roots. The discrepancy between the roots and surrounding soils creates a dielectric constant contrast, forming clear hyperbolic reflections on the GPR radargram. The intensity and shape of the reflecting signals from roots are substantially affected by the root orientation as well as the relative geometry between the root in the subsurface and the GPR survey direction on the ground surface. However, no previous study has utilized the information on the intensity and shape of a root’s GPR reflection to map its orientation, which is crucial in interpreting radargrams and rebuilding 3-D root system architecture. In this paper, a mathematical formulation of hyperbolic reflection formed by a single root was first deduced based on the principles of electromagnetic wave propagation. Then, using this formulation, curve fitting was conducted on both simulated and field collected data sets by GPR. Information on the horizontal orientation and vertical inclination of a single root was acquired according to the formulation coefficient retrievals. Conditions for this method of application and factors impacting the extraction of root orientation information were analyzed. The results indicated fairly precise root orientation estimations. The proposed method has extended the application of GPR in root investigation, thus advancing the frontier of noninvasive root system architecture mapping.
Autors: Qixin Liu;Xihong Cui;Xinbo Liu;Jin Chen;Xuehong Chen;Xin Cao;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jan 2018, volume: 56, issue:1, pages: 93 - 104
Publisher: IEEE
 
» Detector Based Radio Tomographic Imaging
Abstract:
Received signal strength based radio tomographic imaging is a popular device-free indoor localization method which reconstructs the spatial loss field of the environment using measurements from a dense wireless network. Existing methods achieve high accuracy localization using a complex system with many sophisticated components. In this work, we propose an alternative and simpler imaging system based on link level occupancy detection. First, we introduce a single-bounce reflection based received signal strength model, which allows relating received signal strength variations to a large region around the link-lines. Then, based on the model, we present methods for all system components including a classifier, a detector, a back-projection based reconstruction algorithm, and a localization method. The introduced system has the following advantages over the other imaging based methods: i) a simple image reconstruction method that is straightforward to implement; ii) significantly lower computational complexity such that no floating point multiplication is required; iii) each link's measured data are compressed to a single bit, providing improved scalability; and iv) physically significant and repeatable parameters. The proposed method is validated using measurement data. Results show that the proposed method achieves the above advantages without loss of accuracy compared to the other available methods.
Autors: Hüseyin Yiğitler;Riku Jäntti;Ossi Kaltiokallio;Neal Patwari;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2018, volume: 17, issue:1, pages: 58 - 71
Publisher: IEEE
 
» Detector Blur and Correlated Noise Modeling for Digital Breast Tomosynthesis Reconstruction
Abstract:
This paper describes a new image reconstruction method for digital breast tomosynthesis (DBT). The new method incorporates detector blur into the forward model. The detector blur in DBT causes correlation in the measurement noise. By making a few approximations that are reasonable for breast imaging, we formulated a regularized quadratic optimization problem with a data-fit term that incorporates models for detector blur and correlated noise (DBCN). We derived a computationally efficient separable quadratic surrogate (SQS) algorithm to solve the optimization problem that has a non-diagonal noise covariance matrix. We evaluated the SQS-DBCN method by reconstructing DBT scans of breast phantoms and human subjects. The contrast-to-noise ratio and sharpness of microcalcifications were analyzed and compared with those by the simultaneous algebraic reconstruction technique. The quality of soft tissue lesions and parenchymal patterns was examined. The results demonstrate the potential to improve the image quality of reconstructed DBT images by incorporating the system physics model. This paper is a first step toward model-based iterative reconstruction for DBT.
Autors: Jiabei Zheng;Jeffrey A. Fessler;Heang-Ping Chan;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2018, volume: 37, issue:1, pages: 116 - 127
Publisher: IEEE
 
» Determination of Minimum Detectable Deformation of Terrestrial Laser Scanning Based on Error Entropy Model
Abstract:
Terrestrial laser scanning (TLS) is a widely used remote sensing technique which can produce very dense point cloud data very promptly and is particularly suited for surface deformation monitoring. Deformation magnitude is typically estimated by comparing TLS scans over the same area but at different time epochs of interest. However, there is an issue related to such a method, which is not clear that whether the difference between two successive surveys results from the surface deformation. Hence, it is vital to determine the minimum detectable deformation (MDD) by a TLS device with a given registration and point cloud error level. In this paper, the MDD is determined based on the computation of the point cloud error entropy. The performance of the proposed method is extensively evaluated numerically using simulated plane board deformation point clouds under a range of distances and incidence angles. This proposed method was also successfully applied to deformation monitoring of one landslide test site located in the Wuhan University of Technology. The experimental results demonstrate that the theoretical MDD has a good match with the actual deformation, and the deformation greater than MDD can be accurately detected by the TLS device.
Autors: Xijiang Chen;Kegen Yu;Hao Wu;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jan 2018, volume: 56, issue:1, pages: 105 - 116
Publisher: IEEE
 
» Determination of Nerve Fiber Diameter Distribution From Compound Action Potential: A Continuous Approach
Abstract:
When a signal is initiated in the nerve, it is transmitted along each nerve fiber via an action potential (called single fiber action potential (SFAP)) which travels with a velocity that is related with the diameter of the fiber. The additive superposition of SFAPs constitutes the compound action potential (CAP) of the nerve. The fiber diameter distribution (FDD) in the nerve can be computed from the CAP data by solving an inverse problem. This is usually achieved by dividing the fibers into a finite number of diameter groups and solve a corresponding linear system to optimize FDD. However, number of fibers in a nerve can be measured sometimes in thousands and it is possible to assume a continuous distribution for the fiber diameters which leads to a gradient optimization problem. In this paper, we have evaluated this continuous approach to the solution of the inverse problem. We have utilized an analytical function for SFAP and an assumed a polynomial form for FDD. The inverse problem involves the optimization of polynomial coefficients to obtain the best estimate for the FDD. We have observed that an eighth order polynomial for FDD can capture both unimodal and bimodal fiber distributions present in vivo, even in case of noisy CAP data. The assumed FDD distribution regularizes the ill-conditioned inverse problem and produces good results.
Autors: M. Kerem Ün;Hamed Kaghazchi;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Jan 2018, volume: 26, issue:1, pages: 77 - 83
Publisher: IEEE
 
» Determination of the oxidation induction time of mineral insulating oils using a modified EN 14112 method
Abstract:
The most common cause of chemical aging of insulating oils is oxidation. Inhibited oils are insulating oils to which an oxidation inhibitor such as 2,6 ditertiary-butyl phenol or 2,6 dietertiary-butyl cresol has been added in order to slow the rate of oxidation [1]–[3]. The oxidation induction time (OIT) is the time at which the oxidation inhibitor has been exhausted.
Autors: Helena M. Wilhelm;Paulo O. Fernandes;Leandro G. Feitosa;Geovana C. Dos Santos;Giorgi Dal Pont;Andreza Balielo;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: Jan 2018, volume: 34, issue:1, pages: 7 - 14
Publisher: IEEE
 
» Development and Evaluation of an Axial Gap Motor Using Neodymium Bonded Magnet
Abstract:
In general, radial gap motors employing neodymium sintered permanent magnet (Nd sintered PM) are used to achieve high torque density in many applications. However, the motors are not suited to a flat, disk-like shape because the dead space, such as the coil ends, occupies most of the motor volume. Therefore, axial gap motors are frequently used for flat shape instead of radial gap motors. Nd sintered PM is a well-known high-performance magnet that has high residual magnetic flux density, but eddy current loss easily occurs in the magnet because of its high conductivity. In axial gap motors for industrial applications, it is difficult to take measures against eddy current loss of Nd sintered PM in terms of cost. Therefore, general axial gap motors employing Nd sintered PM often have unsatisfactory characteristics, such as low efficiency, even though the motor produces high torque. On the other hand, radial gap motors can take measures to suppress eddy current in PMs easily if radial gap motors employ interior permanent magnet structure. Accordingly, this paper discusses an axial gap motor employing neodymium bonded permanent magnet (Nd bonded PM) for flat shape. Compared with Nd sintered PM, Nd bonded PM has lower residual magnetic flux density, but also lower cost. In addition, Nd bonded PM has extremely low eddy current loss due to its low conductivity. It is found from three-dimensional finite element analysis and experimental results that the axial gap motor employing Nd bonded PM can achieve higher torque and higher efficiency compared with the radial gap motor employing Nd sintered PM with the same PM weight and a flat shape.
Autors: Ren Tsunata;Masatsugu Takemoto;Satoshi Ogasawara;Asako Watanabe;Tomoyuki Ueno;Koji Yamada;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jan 2018, volume: 54, issue:1, pages: 254 - 262
Publisher: IEEE
 
» Development of a 0.6-MV Ultracompact Magnetic Core Pulsed Transformer for High-Power Applications
Abstract:
The generation of high-power electromagnetic waves is one of the major applications in the field of high-intensity pulsed power. The conventional structure of a pulsed power generator contains a primary energy source and a load separated by a power-amplification system. The latter performs time compression of the slow input energy pulse and delivers a high-intensity power output to the load. Usually, either a Marx generator or a Tesla transformer is used as a power amplifier. In the present case, a system termed “module oscillant utilisant une nouvelle architecture” (MOUNA) uses an innovative and very compact resonant pulsed transformer to drive a dipole antenna. This paper describes the ultracompact multiprimary winding pulsed transformer developed in common by the Université de Pau and Hi Pulse Company that can generate voltage pulses of up to 0.6 MV, with a rise time of less than 270 ns. The transformer design has four primary windings, with two secondary windings in parallel, and a Metglas 2605SA1 amorphous iron magnetic core with an innovative biconic geometry used to optimize the leakage inductance. The overall unit has a weight of 6 kg and a volume of only 3.4 L, and this paper presents in detail its design procedure, with each of the main characteristics being separately analyzed. In particular, simple but accurate analytical calculations of both the leakage inductance and the stray capacitance between the primary and secondary windings are presented and successfully compared with CST-based results. Phenomena such as the core losses and saturation induction are also analyzed. The resonant power-amplifier output characteristics are experimentally studied when attached to a compact capacitive load, coupled to a capacitive voltage probe developed jointly with Loughborough University. Finally, an LTspice-based model of the power amplifier is introduced and its predictions are compared with results obtaine- from a thorough experimental study.
Autors: Laurent Pécastaing;Marc Rivaletto;Antoine Silvestre de Ferron;Romain Pecquois;Bucur M. Novac;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2018, volume: 46, issue:1, pages: 156 - 166
Publisher: IEEE
 
» Development of a high-performance indirectly hydrogen-cooled turbine generator [News from Japan]
Abstract:
Global warming caused by CO2 emission, and continuously growing power demands world-wide, are of considerable concern. Among the various types of electric power generation systems, thermal power generation is the largest emitter of CO2. Thus reducing the CO2 emission from thermal power generation plants by increasing their efficiency is an important task for the manufacturers of such plants. Thermal power plants and turbine generators are therefore required to supply electric power more efficiently, where efficiency is defined as generator efficiency.
Autors: Y. Ohki;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: Jan 2018, volume: 34, issue:1, pages: 61 - 63
Publisher: IEEE
 
» Development of a Novel Single-Channel, 24 cm2, SiPM-Based, Cryogenic Photodetector
Abstract:
We report on the realization of a novel silicon photomultiplier (SiPM)-based, cryogenic photosensor with an active area of 24 cm2 that operates as a single-channel analog detector. The device is capable of single-photon counting with a signal-to-noise ratio better than 13, a dark rate lower than Hz/mm2, and an overall photon detection efficiency significantly larger than traditional photomultiplier tubes. This development makes SiPM-based photosensors strong candidates for the next generation of dark matter and neutrino detectors, which will require multiple square meters of photosensitive area, low levels of intrinsic radioactivity, and a limited number of detector channels.
Autors: Marco D’Incecco;Cristiano Galbiati;Graham K. Giovanetti;George Korga;Xinran Li;Andrea Mandarano;Alessandro Razeto;Davide Sablone;Claudio Savarese;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Jan 2018, volume: 65, issue:1, pages: 591 - 596
Publisher: IEEE
 
» Development of a Traction Control System Using a Special Type of Sliding Mode Controller for Hybrid 4WD Vehicles
Abstract:
Using a special type of sliding mode controller, a new type of traction control system (TCS) for hybrid four-wheel drive vehicles is developed. This paper makes two major contributions. First, a new electric powertrain architecture with an in-wheel motor at the front wheels and a clutch on the rear of the transmission is proposed for maximum traction force. The in-wheel motors are controlled to cycle near the optimal slip point. Based on the cycling patterns of the front wheels, the desired wheel speed for rear wheel is defined. The rear wheels are controlled to track this defined speed by controlling the clutch torque. Unlike conventional TCS algorithms, the proposed method exploits clutch control instead of brake control. Second, a special type of sliding mode controller which uses a nonlinear characteristic of the tire is proposed. An important distinction between the proposed sliding mode control method and other conventional feedback controllers is that the former does not depend on feedback error but provides the same functionality. Therefore, the practical aspects are emphasized in this paper. The developed method is confirmed in simulations, and the results reveal that the proposed method opens up opportunities for new types of TCS.
Autors: Kyoungseok Han;Mooryong Choi;Byunghwan Lee;Seibum B. Choi;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2018, volume: 67, issue:1, pages: 264 - 274
Publisher: IEEE
 
» Dielectric Characterization of RF-Printed Circuit Board Materials by Microstrip Transmission Lines and Conductor-Backed Coplanar Waveguides Up to 110 GHz
Abstract:
This paper introduces a method for determining the attenuation constant and the dielectric permittivity (Dk) by microstrip lines and/or conductor-backed coplanar waveguides. The method considers several effects (surface waves, frequency-dependent conductance, inductance, and resistance) for obtaining the attenuation constant of the line and the Dk of the substrate out of measurements. For the compensation of conductor properties, an easily applicable formula for any low loss transmission line is derived that avoids extensive simulations. The validity of the method is shown by measurements of two RF-substrate materials up to 110 GHz. The resulting Dk not only shows excellent agreement with available data sheet values, but also extends the investigated frequency range.
Autors: Oliver Huber;Thomas Faseth;Gottfried Magerl;Holger Arthaber;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 237 - 244
Publisher: IEEE
 
» Differentially Private MIMO Filtering for Event Streams
Abstract:
Rigorous privacy-preserving mechanisms that can process and analyze dynamic data streams in real time are required to encourage a wider adoption of many large-scale monitoring and control systems recording the detailed activities of their users, such as intelligent transportation systems, smart grids, or smart buildings. Motivated by scenarios where signals originate from many sensors capturing privacy-sensitive events about individuals and several statistics of interest need to be continuously published in real time, we consider the problem of designing multi-input multi-output (MIMO) systems processing event streams, while providing certain differential privacy guarantees on the input signals. We show how to construct and optimize MIMO extensions of the zero-forcing mechanism, which we previously proposed for single-input single-output systems. Some of these extensions can take a statistical model of the input signals into account. We illustrate our privacy-preserving filter design methodology in two examples: privately monitoring and forecasting occupancy in a building equipped with multiple motion detection sensors, and analyzing the activity of a Markov chain model of a simple shared processing server.
Autors: Jerome Le Ny;Meisam Mohammady;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2018, volume: 63, issue:1, pages: 145 - 157
Publisher: IEEE
 
» Digital Background Calibration With Histogram of Decision Points in Pipelined ADCs
Abstract:
This brief presents a digital background calibration technique for pipelined analog-to-digital converters (ADCs). It is a histogram-based technique and called the correction with histogram of decision points (CHDP). In this method, the capacitor mismatch and residue amplifier gain error and nonlinearity are corrected by estimating the output code of decision points in the residue characteristic. In order to achieve adequate points, the threshold level of sub-ADC is changed and to increase the estimation accuracy, an algorithm named the mapping histogram is presented. CHDP does not require any special analog circuit and its digital logic is simple. Behavioral simulation results of a 12-bit 100 MS/s pipelined ADC indicate that the proposed calibration scheme improves signal-to-noise and distortion ratio and spurious free dynamic range from 34.1 and 35 dB to 68.2 and 75.8 dB, respectively, while needing about samples for the calibration of five stages.
Autors: Peyman Gholami;Mohammad Yavari;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2018, volume: 65, issue:1, pages: 16 - 20
Publisher: IEEE
 
» Digital Complex Delta–Sigma Modulators With Highly Configurable Notches for Multi-Standard Coexistence in Wireless Transmitters
Abstract:
This paper presents a complex delta–sigma modulator (CDSM) designed for integration in a digital transmitter chain targeting multi-standard coexistence with nearby receivers. The use of a DSM has the advantage of increased performance in terms of signal-to-noise-ratio in the band of interest. However, the resulting out-of-band noise becomes an issue for multi-standard coexistence, thus increasing the complexity of the subsequent filtering stage. This constraint could be relaxed in the DSM stage, by placing a complex zero near the frequency band, where a low noise level is needed. This is achieved by cross coupling the in-phase (I) and quadrature (Q) channels, thus obtaining a CDSM. A review of known design methods for CDSM revealed limitations regarding the poles/zeros optimization, and the configurability of the complex zeros placement. The proposed architecture introduces two additional cross couplings from the I and Q quantizers outputs in order to decorrelate the zeros placement and the poles optimization problem. Hence, the improved CDSM can be implemented using existing optimization tools, which reduces considerably the number of iterations and the computational effort. In addition, the resulting modulator can target different coexistence scenarios without the need of redesign, unlike other known methods. Simulation results show a noise level reduction of approximately 20–30-dB near specific frequency bands by the proposed CDSM scheme with respect to standard DSM. Finally, we show an efficient coarse/fine configurability mechanism, which is obtained when introducing additional delays in the cross-coupling paths.
Autors: Răzvan-Cristian Marin;Antoine Frappé;Andreas Kaiser;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jan 2018, volume: 65, issue:1, pages: 343 - 352
Publisher: IEEE
 
» Digital Imaging Tool to Enhance Otolith Microstructure for Estimating Age in Days in Juvenile and Adult Fish
Abstract:
Age estimation based on fish otolith microstructure analysis is a very repetitive and time-consuming task. The lack of appropriate image analysis software, capable of both overlaying a number of images automatically and recording a high number of daily increments, has been a significant limitation in counting and measuring daily growth increments in large otoliths from juvenile and adult fish individuals. This paper presents a new software to assist marine biologists with faster, more efficient, and more reliable microstructure readings of fish otoliths. Open source code is preferred so that software packages can be updated with new image processing algorithms developed by the scientific community. The approach consists of three steps: 1) a single grayscale digital image combining images of different parts of the same fish otolith is obtained using the blind image registration technique fast normalized cross correlation; 2) the growth rings of the image are enhanced for age estimation purposes, using the adaptive histogram equalization technique; and 3) a semiautomatic interactive tool draws a simple polygonal chain along which the microstructures are easily identifiable and the points of interest can be marked, whose data will be saved automatically. This new tool opens up the opportunity of aging juvenile and adult fish individuals at regular intervals by counting growth rings in the otolith microstructure and facilitates working with other calcified pieces of marine species that exhibit a daily ring pattern, such as cephalopod beaks and mollusk shells.
Autors: Enrique Nava;Elisa I. Villar;María C. Clemente;Javier Rey;Alberto García;Lourdes Fernández-Peralta;Carmen G. Piñeiro;Pablo Otero;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Jan 2018, volume: 43, issue:1, pages: 48 - 55
Publisher: IEEE
 
» Dimensionality Reduction on SPD Manifolds: The Emergence of Geometry-Aware Methods
Abstract:
Representing images and videos with Symmetric Positive Definite (SPD) matrices, and considering the Riemannian geometry of the resulting space, has been shown to yield high discriminative power in many visual recognition tasks. Unfortunately, computation on the Riemannian manifold of SPD matrices –especially of high-dimensional ones– comes at a high cost that limits the applicability of existing techniques. In this paper, we introduce algorithms able to handle high-dimensional SPD matrices by constructing a lower-dimensional SPD manifold. To this end, we propose to model the mapping from the high-dimensional SPD manifold to the low-dimensional one with an orthonormal projection. This lets us formulate dimensionality reduction as the problem of finding a projection that yields a low-dimensional manifold either with maximum discriminative power in the supervised scenario, or with maximum variance of the data in the unsupervised one. We show that learning can be expressed as an optimization problem on a Grassmann manifold and discuss fast solutions for special cases. Our evaluation on several classification tasks evidences that our approach leads to a significant accuracy gain over state-of-the-art methods.
Autors: Mehrtash Harandi;Mathieu Salzmann;Richard Hartley;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2018, volume: 40, issue:1, pages: 48 - 62
Publisher: IEEE
 
» Direct and Two-Step Positioning in Visible Light Systems
Abstract:
Visible light positioning (VLP) systems based on light emitting diodes can facilitate high accuracy localization services for indoor scenarios. In this paper, direct and two-step positioning approaches are investigated for both synchronous and asynchronous VLP systems. First, the Cramér–Rao lower bound (CRLB) and the direct positioning-based maximum likelihood estimator are derived for 3-D localization of a visible light communication receiver in a synchronous scenario by utilizing information from both time delay parameters and channel attenuation factors. Then, a two-step position estimator is designed for synchronous VLP systems by exploiting the asymptotic properties of time-of-arrival and received signal strength estimates. The proposed two-step estimator is shown to be asymptotically optimal, i.e., converges to the direct estimator at high signal-to-noise ratios. In addition, the CRLB and the direct and two-step estimators are obtained for positioning in asynchronous VLP systems. It is proved that the two-step position estimation is optimal in asynchronous VLP systems for practical pulse shapes. Various numerical examples are provided to illustrate the improved performance of the proposed estimators with respect to the current state-of-the-art and to investigate their robustness against model uncertainties in VLP systems.
Autors: Musa Furkan Keskin;Sinan Gezici;Orhan Arikan;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2018, volume: 66, issue:1, pages: 239 - 254
Publisher: IEEE
 
» Direct Least Square Fitting of Hyperellipsoids
Abstract:
This paper presents two new computationally efficient direct methods for fitting n-dimensional ellipsoids to noisy data. They conduct the fitting by minimizing the algebraic distance in subject to suitable quadratic constraints. The hyperellipsoid-specific (HES) method is an elaboration of existing ellipse and 3D ellipsoid-specific fitting methods. It is shown that HES is ellipsoid-specific in n-dimensional space. A limitation of HES is that it may provide biased fitting results with data originating from an ellipsoid with a large ratio between the longest and shortest main axis. The sum-of-discriminants (SOD) method does not have such a limitation. The constraint used by SOD rejects a subset of non-ellipsoidal quadrics, which enables a high tendency to produce ellipsoidal solutions. Moreover, a regularization technique is presented to force the solutions towards ellipsoids with SOD. The regularization technique is compatible also with several existing 2D and 3D fitting methods. The new methods are compared through extensive numerical experiments with n-dimensional variants of three commonly used direct fitting approaches for quadratic surfaces. The results of the experiments imply that in addition to the superior capability to create ellipsoidal solutions, the estimation accuracy of the new methods is better or equal to that of the reference approaches.
Autors: Martti Kesäniemi;Kai Virtanen;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2018, volume: 40, issue:1, pages: 63 - 76
Publisher: IEEE
 
» Direct Measurements of Adiabatic Temperature Change in Ni49.9Mn37.03Sb12.3Fe0.77 Alloy due to Magnetocaloric Effect in the Temperature Range of Martensitic Transformation
Abstract:
The magnetic and magnetocaloric measurements are reported for Ni49.9Mn37.03Sb12.3Fe0.77. The application of magnetic field was found to result in a shift of characteristic temperatures of the martensitic transformation (MT) by 0.7 K/T. Direct measurements of magnetocaloric effect (MCE) were employed to evaluate potential of this alloy for magnetic refrigeration. Peak values of MCE in magnetic field of 5 T were determined to be ~ −0.6 K in the interval of MT, and ~1 K in the vicinity of Curie temperature.
Autors: S. M. Konoplyuk;A. V. Mashirov;A. P Kamantsev;V. V. Koledov;A. V. Koshelev;V. G. Shavrov;V. V. Kokorin;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2018, volume: 54, issue:1, pages: 1 - 4
Publisher: IEEE
 
» Direction Finding for Wideband Source Signals via Steered Effective Projection
Abstract:
A direction-of-arrival (DOA) estimation method for wideband source signals is proposed in the paper based on broadside steering. The steered effective noise subspace is constructed for each steering angle by collecting a certain number of subordinate eigenvectors of the steered array output covariance matrix according to the effective rank of its noise free version. The steered effective projection (STEP) based wideband direction finding then is realized as the steered effective noise subspace towards a true DOA of signal is shown to be: 1) orthogonal to a 1-D subspace spanned by an all-one vector with one single signal present and 2) approximately orthogonal to a 1-D subspace spanned by an all-one vector in the presence of multiple uncorrelated signals. The STEP method requires no preliminary DOA estimates for data focusing. It differs from the existing effective subspace based broad-band signal-subspace spatial spectrum (BASS-ALE) technique in three respects: 1) STEP employs the steered array output covariance matrices towards all the scanning angles while BASS-ALE takes into account only the (focused) array output covariance matrix; 2) STEP performs frequency independent effective subspace projections by constructing the steered effective noise subspace towards each scanning angle while BASS-ALE uses frequency dependent effective subspace projection by constructing only one (focused) effective noise subspace; and 3) STEP can be realized by spatial-only processing while BASS-ALE needs spatio-temporal joint processing to avoid ambiguity in frequency-angle pairs. The performance of the STEP method has been evaluated by extensive simulations, and compared with some current popular wideband DOA estimators.
Autors: Bingjie Yin;Yougen Xu;Yulin Huang;Ying Lu;Zhiwen Liu;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 741 - 751
Publisher: IEEE
 
» Direction-of-Arrival Estimation Enhancement for Closely Spaced Electrically Small Antenna Array
Abstract:
In this paper, compact direction finding systems using a scatterer of a high dielectric constant in between adjacent closely spaced electrically small antennas are examined. By adding a high-permittivity scatterer, the directional sensitivity can be enhanced. However, due to limited physical dimension, an electrically small antenna has highly reactive impedance. To enhance the received power level, a matching network is included. The highest directional sensitivity satisfying a given power constraint is compared for with and without scatterer cases. In addition, widely used matching approaches such as multiport-conjugate matching (MCM), self-conjugate matching (SCM), and eigenmode decoupling matching are investigated to increase the received power. The impact of these matching networks on the directional sensitivity is studied. The power and the directional-sensitivity bandwidth after matching are also analyzed. Finally, the two-monopole and a high-permittivity scatterer system with SCM and MCM circuits is fabricated and tested.
Autors: Xiaoju Yu;Hao Xin;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 477 - 484
Publisher: IEEE
 
» Direction-of-Arrival Estimation in Conformal Microstrip Patch Array Antenna
Abstract:
The direction-of-arrival (DOA) estimation of a conformal antenna array with directive elements is studied in this communication. The two-dimension Cramer–Rao lower bound (CRLB) is derived for a conformal antenna array by using the active directive radiation patterns of the array elements and compared with the isotropic ones. Moreover, the MUSIC method is used to confirm the CRLB results. Without loss of generality, the CRLB of a truncated hexagonal pyramid conformal array with seven patches is investigated which verify the significant effect of the directive elements in the DOA estimation accuracy rather than that of the isotropic ones. The simulation results prove that this conformal array achieves better DOA estimation performance rather than that of the planar array antenna especially at the horizon angles. Moreover, the conformal antenna array tilt angle is studied to achieve the optimum conformal array structure which depicts a tradeoff between the DOA estimation accuracy at low and high incident angles.
Autors: Sirous Mohammadi;Armin Ghani;Seyed Hassan Sedighy;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 511 - 515
Publisher: IEEE
 
» Directional Enhancement Analysis of All-Dielectric Optical Nanoantennas Based on SIE Formulation
Abstract:
Recent advances in optical nanoantennas made of high-permittivity low-loss dielectric particles have demanded efficient numerical modeling techniques for electromagnetic radiation and scattering simulations. Here, the facing requirements of fast convergence of iteration methods and good accuracy of results, a modified surface integral equation for high-permittivity objects has been presented. Moreover, based on the proposed surface integral equation, a full study of the dependence of the radiation pattern on the relative permittivity and wavelength has been performed for a single-dielectric nanoparticle with the excitation of an electric dipole source. Then, the directional enhancement of radiation is explored from Yagi-Uda geometry systems made of nanoparticles with optimal permittivities for reflector and directors.
Autors: Xin Qi;Zaiping Nie;Yongpin Chen;Xiaofeng Que;Jun Hu;Yue Wang;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2018, volume: 30, issue:1, pages: 123 - 126
Publisher: IEEE
 
» Discrete Fresnel Transform Spread OFDM for Coherent Optical Fiber Communication
Abstract:
In the polarization-division multiplexed coherent optical fiber communication, conventional orthogonal frequency-division multiplexing (OFDM) and discrete Fourier transform spread OFDM (DFT-S-OFDM) sacrifice the baud rate with either zero-padded subcarriers in the high-frequency region to mitigate the frequency fading, or with a large cyclic prefix (CP) to eliminate the residual inter-symbol interference (ISI). In this letter, we propose a discrete Fresnel transform spread OFDM (DFnT-S-OFDM) scheme, which spreads information over both temporal and frequency dimensions. A low-complexity encoder was also developed for the proposed precoding scheme. Simulations show that DFnT-S-OFDM is more resilient against the frequency fading than OFDM and against the residual ISI than DFT-S-OFDM. Therefore, it maximizes the net data rate by reducing the CP length or increasing the useful signal bandwidth.
Autors: Yukui Yu;Wei Wang;Xing Ouyang;Zhenpeng Wang;Jian Zhao;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2018, volume: 30, issue:1, pages: 91 - 94
Publisher: IEEE
 
» Discrete Power Control and Transmission Duration Allocation for Self-Backhauling Dense mmWave Cellular Networks
Abstract:
Wireless self-backhauling is a promising solution for dense millimeter wave (mmWave) small cell networks, the system efficiency of which, however, depends upon the balance of resources between the backhaul link and access links of each small cell. In this paper, we address the discrete power control and non-unified transmission duration allocation problem for self-backhauling mmWave cellular networks, in which each small cell is allowed to adopt individual transmission duration allocation ratio according to its own channel and load conditions. We first formulate the considered problem as a non-cooperative game with a common utility function. We prove the feasibility and existence of the pure strategy Nash equilibrium (NE) of game under some mild conditions. Then, we design a centralized resource allocation algorithm based on the best response dynamic and a decentralized resource allocation algorithm (DRA) based on control-plane/user-plane split architecture and log-linear learning to obtain a feasible pure strategy NE of game . For speeding up convergence and reducing signaling overheads, we reformulate the considered problem as a non-cooperative game with local interaction, in which only local information exchange is required. Based on DRA, we design a concurrent DRA to obtain the best feasible pure strategy NE of game . Furthermore, we extend the proposed algorithms to the discrete power control and unified transmission duration allocation optimization problem. Extensive simulations are conducted with different syste- configurations to demonstrate the convergence and effectiveness of the proposed algorithms.
Autors: Yanping Liu;Xuming Fang;Ming Xiao;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2018, volume: 66, issue:1, pages: 432 - 447
Publisher: IEEE
 
» Discriminative Dimensionality Reduction for Multi-Dimensional Sequences
Abstract:
Since the observables at particular time instants in a temporal sequence exhibit dependencies, they are not independent samples. Thus, it is not plausible to apply i.i.d. assumption-based dimensionality reduction methods to sequence data. This paper presents a novel supervised dimensionality reduction approach for sequence data, called Linear Sequence Discriminant Analysis (LSDA). It learns a linear discriminative projection of the feature vectors in sequences to a lower-dimensional subspace by maximizing the separability of the sequence classes such that the entire sequences are holistically discriminated. The sequence class separability is constructed based on the sequence statistics, and the use of different statistics produces different LSDA methods. This paper presents and compares two novel LSDA methods, namely M-LSDA and D-LSDA. M-LSDA extracts model-based statistics by exploiting the dynamical structure of the sequence classes, and D-LSDA extracts the distance-based statistics by computing the pairwise similarity of samples from the same sequence class. Extensive experiments on several different tasks have demonstrated the effectiveness and the general applicability of the proposed methods.
Autors: Bing Su;Xiaoqing Ding;Hao Wang;Ying Wu;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2018, volume: 40, issue:1, pages: 77 - 91
Publisher: IEEE
 
» Disinformatics: The Discipline behind Grand Deceptions
Abstract:
We need to bring serious study of misinformation and deception into the academy for analysis. A new discipline might be just the vehicle.
Autors: Hal Berghel;
Appeared in: Computer
Publication date: Jan 2018, volume: 51, issue:1, pages: 89 - 93
Publisher: IEEE
 
» Dispersion Analysis of 2-D Glide-Symmetric Corrugated Metasurfaces Using Mode-Matching Technique
Abstract:
In this letter, wave propagation in 2-D doubled corrugated metasurfaces, including glide-symmetric corrugated metasurfaces, embedded in a thin parallel plate waveguide have been analyzed using the mode matching method. The general dispersion equation for propagation at different directions is derived and dispersion surfaces have been obtained for three different cases. The results are in good agreement with reference results obtained using CST Microwave Studio. Moreover, the method is accurate and computationally much faster than CST Microwave Studio and similar commercial software.
Autors: Fatemeh Ghasemifard;Martin Norgren;Oscar Quevedo-Teruel;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jan 2018, volume: 28, issue:1, pages: 1 - 3
Publisher: IEEE
 
» Distinguishing Cyanobacterial Bloom From Floating Leaf Vegetation in Lake Taihu Based on Medium-Resolution Imaging Spectrometer (MERIS) Data
Abstract:
Based on field measurements of water surface reflectance spectra in Lake Taihu, we construct a model for distinguishing between cyanobacterial bloom and floating leaf vegetation by combining a chlorophyll spectral index with a baseline of phycocyanin. In situ measurements validation results show that this model performs well in distinguishing cyanobacterial bloom from floating leaf vegetation in Lake Taihu. We apply this model to 52 remote sensing images from the Medium-Resolution Imaging Spectrometer (MERIS) from 2003 to 2011. Using two different accuracy evaluation methods, we find an average recognition accuracy of more than 80% for cyanobacterial bloom and floating leaf vegetation when using optimal index thresholds. Using an average index threshold to extract cyanobacterial bloom and floating leaf vegetation from the images, the relative accuracies are 78.8% and 74.6%, respectively. If more efficiency is desired, these average thresholds can be used, which is convenient for batch processing and automated extraction of cyanobacterial bloom and floating leaf vegetation from remote sensing data. The overall distribution of cyanobacterial bloom and floating leaf vegetation in Lake Taihu from 2003 to 2011 is determined by overlapping the distribution maps from individual images, and the results of our analysis are consistent with previously published results. In addition, our analysis shows that this model is immune to perturbations from thin clouds and aerosols.
Autors: Qing Zhu;Junsheng Li;Fangfang Zhang;Qian Shen;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jan 2018, volume: 11, issue:1, pages: 34 - 44
Publisher: IEEE
 
» Distortion Correction in Fetal EPI Using Non-Rigid Registration With a Laplacian Constraint
Abstract:
Geometric distortion induced by the main B0 field disrupts the consistency of fetal echo planar imaging (EPI) data, on which diffusion and functional magnetic resonance imaging is based. In this paper, we present a novel data-driven method for simultaneous motion and distortion correction of fetal EPI. A motion-corrected and reconstructed T2 weighted single shot fast spin echo (ssFSE) volume is used as a model of undistorted fetal brain anatomy. Our algorithm interleaves two registration steps: estimation of fetal motion parameters by aligning EPI slices to the model; and deformable registration of EPI slices to slices simulated from the undistorted model to estimate the distortion field. The deformable registration is regularized by a physically inspired Laplacian constraint, to model distortion induced by a source-free background B0 field. Our experiments show that distortion correction significantly improves consistency of reconstructed EPI volumes with ssFSE volumes. In addition, the estimated distortion fields are consistent with fields calculated from acquired field maps, and the Laplacian constraint is essential for estimation of plausible distortion fields. The EPI volumes reconstructed from different scans of the same subject were more consistent when the proposed method was used in comparison with EPI volumes reconstructed from data distortion corrected using a separately acquired B0 field map.
Autors: Maria Kuklisova-Murgasova;Georgia Lockwood Estrin;Rita G. Nunes;Shaihan J. Malik;Mary A. Rutherford;Daniel Rueckert;Joseph V. Hajnal;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2018, volume: 37, issue:1, pages: 12 - 19
Publisher: IEEE
 
» Distributed Control of PEV Charging Based on Energy Demand Forecast
Abstract:
This paper presents a new distributed smart charging strategy for grid integration of plug-in electric vehicles (PEVs). The main goal is to smooth the daily grid load profile while ensuring that each PEV has a desired state of charge level at the time of departure. Communication and computational overhead, and PEV user privacy are also considered during the development of the proposed strategy. It consists of two stages: 1) an offline process to estimate a reference operating power level based on the forecasted mobility energy demand and base loading profile, and 2) a real-time process to determine the charging power for each PEV so that the aggregated load tracks the reference loading level. Tests are carried out both on primary and secondary distribution networks for different heuristic charging scenarios and PEV penetration levels. Results are compared to that of the optimal solution and other state-of-the-art techniques in terms of variance and peak values, and shown to be competitive. Finally, a real vehicle test implementation is done using a commercial-of-the-shelf charging station and an electric vehicle.
Autors: Mithat C. Kisacikoglu;Fatih Erden;Nuh Erdogan;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 332 - 341
Publisher: IEEE
 
» Distributed Diameter Subcoil Twisted Loop Antenna in Nonradiative WPT
Abstract:
This letter focuses on the high-frequency wireless power transfer by electromagnetic induction and its dependence on the lateral misalignment and tilt of the small receiving coil relative to the transmitting coil. We combine two structures, the twisted loop antenna (TLA) and subcoils of a distributed diameter coil (DDC) for transmitting designs. Our system is then referred to as TLA-DDC. The radius of the subcoils is parametrically varied for different distances between the coils and performed in two positions for each distance (coaxial position when the receiving coil is parallel to the plane of the transmitting coil, and center position for the perpendicular orientation of both coils). Then, using different radii for the transmitting DDC TLA when the receiving coil is moved onto its surface allows us to obtain a greater value of efficiency at different positions: up to 2.4 times for the peak value and 1.5 for the average value for receiving coil in parallel plane. The efficiency of the magnetic coupling is determined by means of power efficiency with a comparison between the DDC TLA antennas and a standard coil antenna corresponding to the same inductance value.
Autors: Marjorie Grzeskowiak;Antoine Diet;Megdouda Benamara;Patrick Poulichet;Christophe Conessa;Stéphane Protat;Marc Biancheri-Astier;Francisco de Oliveira Alves;Yann Le Bihan;Gaelle Lissorgues;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Jan 2018, volume: 17, issue:1, pages: 4 - 7
Publisher: IEEE
 
» Distributed Event-Based State Estimation for Networked Systems: An LMI Approach
Abstract:
In this paper, a dynamic system is controlled by multiple sensor-actuator agents, each of them commanding and observing parts of the system's input and output. The different agents sporadically exchange data with each other via a common bus network according to local event-triggering protocols. From these data, each agent estimates the complete dynamic state of the system and uses its estimate for feedback control. We propose a synthesis procedure for designing the agents’ state estimators and the event triggering thresholds. The resulting distributed and event-based control system is guaranteed to be stable and to satisfy a predefined estimation performance criterion. The approach is applied to the control of a vehicle platoon, where the method's tradeoff between performance and communication and the scalability in the number of agents are demonstrated.
Autors: Michael Muehlebach;Sebastian Trimpe;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2018, volume: 63, issue:1, pages: 269 - 276
Publisher: IEEE
 
» Distributed Hybrid Scheduling in Multi-Cloud Networks Using Conflict Graphs
Abstract:
Recent studies on cloud-radio access networks assume either signal-level or scheduling-level coordination. This paper considers a hybrid coordinated scheme as a means to benefit from both policies. Consider the downlink of a multi-cloud radio access network, where each cloud is connected to several base-stations (BSs) via high capacity links and, therefore, allows for joint signal processing within the cloud transmission. Across the multiple clouds, however, only scheduling-level coordination is permitted, as low levels of backhaul communication are feasible. The frame structure of every BS is composed of various time/frequency blocks, called power-zones (PZs), which are maintained at a fixed power level. This paper addresses the problem of maximizing a network-wide utility by associating users to clouds and scheduling them to the PZs, under the practical constraints that each user is scheduled to a single cloud at most, but possibly to many BSs within the cloud, and can be served by one or more distinct PZs within the BSs’ frame. This paper solves the problem using graph theory techniques by constructing the conflict graph. The considered scheduling problem is, then, shown to be equivalent to a maximum-weight independent set problem in the constructed graph, which can be solved using efficient techniques. This paper then proposes solving the problem using both optimal and heuristic algorithms that can be implemented in a distributed fashion across the network. The proposed distributed algorithms rely on the well-chosen structure of the constructed conflict graph utilized to solve the maximum-weight independent set problem. Simulation results suggest that the proposed optimal and heuristic hybrid scheduling strategies provide appreciable gain as compared with the scheduling-level coordinated networks, with a negligible degradation to signal-level coordination.
Autors: Ahmed Douik;Hayssam Dahrouj;Tareq Y. Al-Naffouri;Mohamed-Slim Alouini;
Appeared in: IEEE Transactions on Communications
Publication date: Jan 2018, volume: 66, issue:1, pages: 209 - 224
Publisher: IEEE
 
» Distributed Joint Source-Channel Decoding Using Systematic Polar Codes
Abstract:
This letter proposes a novel joint decoding scheme for correlated sources using systematic polar codes. In the proposed scheme, each source independently encodes its message into a systematic polar code word and sends the codeword via a binary-input additive white Gaussian noise channel to the common destination, where adaptive cyclic redundancy check-aided successive cancellation list (CA-SCL) decoders are employed. During the iterative decoding process, the log likelihood ratios (LLRs) fed to each adaptive CA-SCL decoder are iteratively combined with the extrinsic LLRs from other decoders. The correlation among the sources is exploited to improve the decoding performance. Simulation results show that, in comparison with independent decoding, the proposed scheme can achieve significantly improved decoding performance without increased complexity.
Autors: Liqiang Jin;Pei Yang;Hongwen Yang;
Appeared in: IEEE Communications Letters
Publication date: Jan 2018, volume: 22, issue:1, pages: 49 - 52
Publisher: IEEE
 
» Distributed Linearized Alternating Direction Method of Multipliers for Composite Convex Consensus Optimization
Abstract:
Given an undirected graph of agents connected with edges in , we study how to compute an optimal decision on which there is consensus among agents and that minimizes the sum of agent-specific private convex composite functions , where belongs to agent-. Assuming only agents connected by an edge can communicate, we propose a distributed proximal gradient algorithm (DPGA) for consensus optimization over both unweighted and weighted static (undirected) communication networks. In one iteration, each agent- computes the prox map of and gradient of , and this is followed by local communication with neighboring agents. We also study its stochastic gradient variant, SDPGA, which can only access to noisy estimates of at each agent-. This computational model abstracts a number of applications in distributed sensing, machine learning and statistical inference. We show ergodic convergence in both suboptimality error and consensus violation for the DPGA and SDPGA with rates and , respectively.
Autors: N. S. Aybat;Z. Wang;T. Lin;S. Ma;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2018, volume: 63, issue:1, pages: 5 - 20
Publisher: IEEE
 
» Distributed Measurement of Fermi–Pasta–Ulam Recurrence in Optical Fibers
Abstract:
We experimentally demonstrate the distributed measurement of Fermi–Pasta–Ulam (FPU) recurrence in an optical fiber. Square-shaped pulses with weak modulation are injected into a single-mode fiber to exhibit FPU recurrence. Rayleigh backscattering signals of various sidebands are recorded to measure the power vibration along the optical fiber. The validity of the distributed method is confirmed both by the numerical simulation and the cutting-back method. Compared with the traditional cutting-back method, the distributed method has significant advantages, such as short measurement time, low cost, and good repeatability. We also believe that the distributed method has a great potential for the measurement of other nonlinear effects in optical fiber.
Autors: Xiaoyang Hu;Wei Chen;Yang Lu;Zhijie Yu;Mo Chen;Zhou Meng;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2018, volume: 30, issue:1, pages: 47 - 50
Publisher: IEEE
 
» Distributed Multiuser Computation Offloading for Cloudlet-Based Mobile Cloud Computing: A Game-Theoretic Machine Learning Approach
Abstract:
In this paper, we investigate the problem of multiuser computation offloading for cloudlet-based mobile cloud computing in a multichannel wireless contention environment. The studied system is fully distributed so that each mobile device user can make the offloading decisions based only on its individual information, and without information exchange. We first formulate this multiuser computation offloading decision making problem as a noncooperative game. After analyzing the structural property of the formulated game, we show that it is an exact potential game, and has at least one pure-strategy Nash equilibrium point (NEP). To achieve the NEPs in a fully distributed environment, we propose a fully distributed computation offloading (FDCO) algorithm based on machine learning technology. We then theoretically analyze the performance of the proposed FDCO algorithm in terms of the number of beneficial cloudlet computing mobile devices and the system-wide execution cost. Finally, simulation results validate the effectiveness of our proposed algorithm compared with counterparts.
Autors: Huijin Cao;Jun Cai;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jan 2018, volume: 67, issue:1, pages: 752 - 764
Publisher: IEEE
 
» Distributed Partitioning Algorithms for Locational Optimization of Multiagent Networks in SE(2)
Abstract:
This paper is concerned with the development of distributed spatial partitioning algorithms for locational optimization problems involving networks of agents with planar rigid body dynamics subject to communication constraints. The domain of the problems we consider is a three-dimensional (3-D) nonflat manifold embedded in the state space of the agents, which we refer to as the terminal manifold. The approach we propose allows us to associate the partition of the 3-D terminal manifold, which is induced by a nonquadratic proximity metric and comprised of nonconvex cells, with a one-parameter family of partitions of 2-D flat manifolds, which are induced by (parametric) quadratic proximity metrics and comprised of convex polygonal cells. By exploiting the special structure of the parametric partitions, we develop distributed partitioning algorithms that converge in a finite number of steps. Subsequently, we utilize the solutions to the latter problems to solve a class of locational optimization problems over the terminal manifold. Numerical simulations that illustrate the capabilities of the proposed algorithms are also presented.
Autors: Efstathios Bakolas;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2018, volume: 63, issue:1, pages: 101 - 116
Publisher: IEEE
 
» Distributed Sequential Estimation in Wireless Sensor Networks
Abstract:
This paper considers the problem of decentralized sequential estimation in dynamic wireless sensor networks. A coherent medium access control layer is considered, and optimal linear precoder and decoder matrices are designed to minimize the mean square error (MSE) in an online setting. Different from the state-of-the-art decentralized estimators, the proposed framework is flexible enough to handle time-varying parameters, channel gains, and power constraints. Although the general transceiver design problem is nonconvex, a fast block coordinate descent-based method is proposed that incurs very low complexity and yields near-optimal solutions. Motivated by the need to reduce the communication overhead incurred by the centralized schemes, two fully distributed transceiver design algorithms that make use of the constrained linear minimum MSE machinery are also advocated. The resulting approximate precoders are not only near optimal but can also be calculated locally at each sensor. Finally, the entire framework is generalized so as to allow tracking of parameters that follow a known state-space model. Extensive simulations are provided to demonstrate the efficacy of the proposed class of algorithms.
Autors: Javed Akhtar;Ketan Rajawat;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2018, volume: 17, issue:1, pages: 86 - 100
Publisher: IEEE
 
» Distribution Optimal Power Flow With Real-Time Price Elasticity
Abstract:
This letter investigates a new class of optimal power flow problem for distribution systems, where elastic loads respond to real-time nodal prices by adjusting their demands. A fixed-point iteration algorithm is suggested to identify an equilibrium. A concise criterion is devised to judge convergence.
Autors: Wei Wei;Jianhui Wang;Lei Wu;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 1097 - 1098
Publisher: IEEE
 
» Distributionally Robust Contingency-Constrained Unit Commitment
Abstract:
This paper proposes a distributionally robust optimization approach for the contingency-constrained unit commitment problem. In our approach, we consider a case where the true probability distribution of contingencies is ambiguous, i.e., difficult to accurately estimate. Instead of assigning a (fixed) probability estimate for each contingency scenario, we consider a set of contingency probability distributions (termed the ambiguity set) based on the security criterion and moment information. Our approach considers all possible distributions in the ambiguity set, and is hence distributionally robust. Meanwhile, as this approach utilizes moment information, it can benefit from available data and become less conservative than the robust optimization approaches. We derive an equivalent reformulation and study a Benders’ decomposition algorithm for solving the model. Furthermore, we extend the model to incorporate wind power uncertainty. The case studies on a 6-Bus system and the IEEE 118-Bus system demonstrate that the proposed approach provides less conservative unit commitment decisions as compared with the robust optimization approach.
Autors: Chaoyue Zhao;Ruiwei Jiang;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 94 - 102
Publisher: IEEE
 
» Distributionally Robust Optimal Bidding of Controllable Load Aggregators in the Electricity Market
Abstract:
An optimal bidding model of controllable loads is proposed to minimize the worst-case conditional expectation of electricity purchase cost simultaneously in day-ahead and real-time markets. By reformulating the worst-case conditional value-at-risk (CVaR) constraints, a solvable semi-definite program (SDP) is presented to relax the moment uncertainty of electricity price and simultaneously determine the optimal day-ahead bid and real-time increment/decrement bid.
Autors: Hongming Yang;Shiming Zhang;Duo Qiu;Junhua Zhao;Mingyong Lai;Zhao Yang Dong;Zhao Hui Dong;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 1089 - 1091
Publisher: IEEE
 
» Disturbance Compensation With Finite Spectrum Assignment for Plants With Input Delay
Abstract:
This paper presents a method for compensation of unknown bounded smooth disturbances for linear time invariant (LTI) plants with known parameters in the presence of constant and known input delay. The proposed control law is a sum of the classical predictor suggested by Manitius and Olbrot for finite spectrum assignment and a disturbance compensator. The disturbance compensator is a novel control law based on the auxiliary loop for disturbance extraction and on the disturbance prediction. A numerical implementation of the integral terms in the predictor-based control law is studied and sufficient conditions in terms of linear matrix inequalities are provided for an estimate on the maximum delay that preserves the stability. Numerical examples illustrate the efficiency of the method.
Autors: Igor Furtat;Emilia Fridman;Alexander Fradkov;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2018, volume: 63, issue:1, pages: 298 - 305
Publisher: IEEE
 

Publication archives by date

  2018:   January     February     March     April     May     June     July     August     September     October     November     December    

  2017:   January     February     March     April     May     June     July     August     September     October     November     December    

  2016:   January     February     March     April     May     June     July     August     September     October     November     December    

  2015:   January     February     March     April     May     June     July     August     September     October     November     December    

  2014:   January     February     March     April     May     June     July     August     September     October     November     December    

  2013:   January     February     March     April     May     June     July     August     September     October     November     December    

  2012:   January     February     March     April     May     June     July     August     September     October     November     December    

  2011:   January     February     March     April     May     June     July     August     September     October     November     December    

  2010:   January     February     March     April     May     June     July     August     September     October     November     December    

  2009:   January     February     March     April     May     June     July     August     September     October     November     December    

 
0-C     D-L     M-R     S-Z