Electrical and Electronics Engineering publications abstract of: 02-2018 sorted by title, page: 2

» A Novel Mutual Coupling Compensation Method for Underdetermined Direction of Arrival Estimation in Nested Sparse Circular Arrays
Abstract:
A simple mutual coupling (MC) compensation method for nested sparse circular arrays that is capable of underdetermined direction-of-arrival (DOA) estimation is proposed. Sparse signal reconstruction (SSR) has offered a renewed interest to the problem of DOA estimation. In SSR framework, DOA estimation is accomplished by finding the sparse coefficients of the array covariance vectors in an overcomplete basis, which achieves high resolution and is statistically robust even in low signal-to-noise ratio. We use a nested sparse circular array composed of dense and sparse parts, which obtains very low MC. Thus, we propose a banded-like circulant MC matrix (MCM), which has a very few MC coefficients. By incorporating the MCM in the DOA estimation problem, the proposed array’s capability of estimating more sources than sensors is improved. As compared with conventional methods, the proposed technique is cost effective and easy to implement, while achieving better performance. Simulation results show that a better underdetermined DOA estimation performance is achieved. We use two methods: subspace based method—MUSIC and SSR method -based optimization.
Autors: Thomas Basikolo;Koichi Ichige;Hiroyuki Arai;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 909 - 917
Publisher: IEEE
 
» A Novel Network Structure with Power Efficiency and High Availability for Data Centers
Abstract:
Designing a cost-effective network for data centers that can deliver sufficient bandwidth and provide high availability has drawn tremendous attentions recently. In this paper, we propose a novel server-centric network structure called RCube, which is energy efficient and can deploy a redundancy scheme to improve the availability of data centers. Moreover, RCube shares many good properties with BCube, a well known server-centric network structure, yet its network size can be adjusted more conveniently. We also present a routing algorithm to find paths in RCube and an algorithm to find multiple parallel paths between any pair of source and destination servers. In addition, we theoretically analyze the power efficiency of the network and availability of RCube under server failure. Our comprehensive simulations demonstrate that RCube provides higher availability and flexibility to make trade-off among many factors, such as power consumption and aggregate throughput, than BCube, while delivering similar performance to BCube in many critical metrics, such as average path length, path distribution and graceful degradation, which makes RCube a very promising empirical structure for an enterprise data center network product.
Autors: Zhenhua Li;Yuanyuan Yang;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Feb 2018, volume: 29, issue:2, pages: 254 - 268
Publisher: IEEE
 
» A Novel Self-Interference Cancellation Scheme for Channel-Unaware Differential Space-Time Two-Way Relay Networks
Abstract:
This paper considers channel-unaware two-way relay networks in which two single-antenna nodes exchange information via multiple non-regenerative relays, each with multiple antennas. A novel self-interference cancellation scheme for distributed differential space-time signalling is developed. Despite the absence of channel-state information, this scheme enables self-interference to be completely eliminated, thereby maximizing the signal-to-interference-plus-noise-ratio of the nodes. First, we obtain a lower bound on the pairwise error probability (PEP) under residual self-interference and we show that this bound approaches a non-zero constant at high signal-to-noise ratios (SNRs), indicating a zero diversity order and an asymptotic error floor. Second, we derive a necessary and sufficient condition for the proposed scheme to eliminate self-interference perfectly. Proper operation of this scheme requires the relays to have an even number of active antennas and for relays with odd number of active antennas, such a scheme does not exist. Third, we show that, when self-interference is cancelled perfectly, the error floor vanishes and an upper bound on the PEP approaches zero at high SNRs. In this case, it is shown that the diversity gain is equal to the number of relays and is independent of the number of antennas per relay. Finally, it is shown that the coding gain increases with increasing the number of antennas per relay and converges to a constant as the number of relay antennas becomes large.
Autors: Salime Bameri;Siamak Talebi;Ramy H. Gohary;Halim Yanikomeroglu;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 1226 - 1241
Publisher: IEEE
 
» A Novel Wide Duty Cycle Range Wide Band High Frequency Isolated Gate Driver for Power Converters
Abstract:
This paper presents a novel single source fed isolated gate driver circuit based on the dual-forward converter topology. The two forward converters are paralleled at the secondary side to achieve 0%–100 duty cycle range together with galvanic isolation. The gate driver switching frequency is independent of the main pulse-width modulation frequency (PWM). As a result, the gate driver switching devices and magnetics are designed for high frequencies independent of the main PWM frequency. At high frequencies, problems of resonance due to parasitics become significant. This paper discusses this problem and proposes a novel solution to mitigate it. In addition, this paper also presents a novel solution and circuit to produce negative gate pulse for miller clamp. The proposed circuit can be used for any application, irrespective of switching frequency, thus making it a wide band generalized gate driver. The circuit is analyzed and verified experimentally.
Autors: B. Satish Naik;S. Shan;L. Umanand;B. Subba Reddy;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 437 - 446
Publisher: IEEE
 
» A Numerically Efficient Method for Predicting the Scattering Characteristics of a Complex Metallic Target Located Inside a Large Forested Area
Abstract:
An efficient electromagnetic model for the scattering analysis of targets placed in large natural environments is presented. A hybrid formulation combining volume and surface integral equations is used to describe forest environment (dielectric objects) in which metallic structures are present. A large part of the forest can be analyzed electromagnetically by using the characteristic basis function method, whose use enables us to simulate the problem at hand and significantly reduce the dimension of the linear system that needs to be solved.
Autors: L. Hettak;H. Roussel;M. Casaletti;R. Mittra;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 1177 - 1185
Publisher: IEEE
 
» A Numerically Stable Solver for Positive Semidefinite Quadratic Programs Based on Nonnegative Least Squares
Abstract:
This paper proposes a new algorithm for solving convex quadratic programs (QP) subject to linear inequality and equality constraints. The method extends an approach recently proposed by the author for solving strictly convex QP's using nonnegative least squares, by making it numerically more robust and able to handle also the nonstrictly convex case, equality constraints, and warm starting from an initial guess. Robustness is achieved by introducing an outer proximal-point iteration scheme that regularizes the problem without altering the solution, and by adaptively weighting the least squares problems encountered while solving the problem. The performance of the resulting QP solver in terms of speed and robustness in the single precision arithmetic is assessed against other optimization algorithms tailored to embedded model predictive control applications.
Autors: Alberto Bemporad;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Feb 2018, volume: 63, issue:2, pages: 525 - 531
Publisher: IEEE
 
» A Parallel Stochastic Number Generator With Bit Permutation Networks
Abstract:
Stochastic computing (SC) is a promising paradigm to realize low-complexity digital circuits that are tolerant to soft errors. Stochastic circuits include a stochastic number generator (SNG) to generate a stochastic number that corresponds to a given binary number. Conventional SNGs, which employ linear feedback shift registers (LFSRs) to generate stochastic numbers in a serial manner would cost significantly in time. In this brief, a parallel SNG has been proposed, which can generate stochastic numbers in parallel by transforming the input binary number to a modified unary number and permuting it using a bit permutation network. Further, a method to share a single LFSR among multiple SNGs has been presented. Experimental results show that the proposed SNG can achieve improvement in SC correlation and energy-delay-product by 28.57% and , respectively, when compared to the existing shared LFSR-based SNG. For applications, such as edge detector, multiplier, and complex multiplication, the proposed SNG has achieved reduction in execution time and area-delay-product by up to and , respectively, as compared to others.
Autors: Vikash Sehwag;N. Prasad;Indrajit Chakrabarti;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Feb 2018, volume: 65, issue:2, pages: 231 - 235
Publisher: IEEE
 
» A Parametric Level Set Method for Electrical Impedance Tomography
Abstract:
This paper presents an image reconstruction method based on parametric level set (PLS) method using electrical impedance tomography. The conductivity to be reconstructed was assumed to be piecewise constant and the geometry of the anomaly was represented by a shape-based PLS function, which we represent using Gaussian radial basis functions (GRBF). The representation of the PLS function significantly reduces the number of unknowns, and circumvents many difficulties that are associated with traditional level set (TLS) methods, such as regularization, re-initialization and use of signed distance function. PLS reconstruction results shown in this article are some of the first ones using experimental EIT data. The performance of the PLS method was tested with water tank data for two-phase visualization and with simulations which demonstrate the most popular biomedical application of EIT: lung imaging. In addition, robustness studies of the PLS method w.r.t width of the Gaussian function and GRBF centers were performed on simulated lung imaging data. The experimental and simulation results show that PLS method has significant improvement in image quality compared with the TLS reconstruction.
Autors: Dong Liu;Anil Kumar Khambampati;Jiangfeng Du;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Feb 2018, volume: 37, issue:2, pages: 451 - 460
Publisher: IEEE
 
» A Part of the Energy "In Crowd": Changing People's Energy Behavior via Group-Based Approaches
Abstract:
One of the most critical and pressing solutions needed to address global climate change is the transition to secure, affordable, and sustainable-energy systems. This transition is usually considered a technological challenge because it involves the integration of renewable energy, a trend toward decentralizing energy generation, and more demandside participation. However, involving consumers in the transition is crucial for its success. For example, sustainable-energy transitions may require consumers to adopt sustainable-energy sources, technologies, and energy-efficiency measures as well as change their direct and indirect energy use behaviors to the limited and fluctuating supply of (renewable) energy. However, such behaviors may not always be easy for consumers to adopt, as they can entail personal sacrifice and discomfort or require them to change habits or infrastructure, which can be cognitively and financially demanding. To guarantee a sustainable future for all, it is critical that we understand what motivates consumers' energy behaviors and how we can promote consumers' motivation to engage in sustainable-energy behaviors and act beyond immediate personal interests.
Autors: Lise Jans;Thijs Bouman;Kelly Fielding;
Appeared in: IEEE Power and Energy Magazine
Publication date: Feb 2018, volume: 16, issue:1, pages: 35 - 41
Publisher: IEEE
 
» A Passive Wireless Microelectromechanical Pressure Sensor for Harsh Environments
Abstract:
A microelectromechanical systems (MEMS) capacitive-type passive wireless pressure sensor designed to operate in harsh environments at temperatures up to 1000 °C is presented. The pressure sensor has a sapphire-based diaphragm and structural body, and a platinum-based capacitive element. The capacitive element is configured as a part of a slot patch antenna that is designed to operate in a far-field sensing mechanism with a Ku-band electrical resonant frequency of 15 GHz. The electrical ground plane resides on the backside of the diaphragm, which deflects in response to an applied pressure. The electrical resonant frequency of the pressure sensor changes as a function of the applied pressure to the diaphragm. An increase in the applied pressure, for example, results in a decrease in the electrical resonant frequency. The sensitivity of the pressure sensor is related to the change in applied pressure to the change in the electrical resonant frequency. Three proof-of-concept dynamic pressure sensors are reported using silicon-based diaphragms with antenna diameters of 5.6, 5.7, and 5.8 mm, and measured sensitivities of 2.2, 2.2, and 5.1 kHz/Pa, respectively, up to 900 Pa. In addition, three proof-of-concept static pressure sensors are reported with corresponding measured sensitivities of 3.4, 3.1, and 2.5 kHz/Pa up to 900 Pa. A high-temperature dynamic pressure sensor designed for harsh environments is also reported using a sapphire-based diaphragm with an antenna diameter of 3.8 mm and measured sensitivity of 21.7 kHz/Pa up to 800 Pa. [2017-0210]
Autors: John E. Rogers;Yong-Kyu Yoon;Mark Sheplak;Jack W. Judy;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Feb 2018, volume: 27, issue:1, pages: 73 - 85
Publisher: IEEE
 
» A Piezoresistive Tactile Sensor Array for Touchscreen Panels
Abstract:
Touchscreen panels (TSPs), as human–machine interfaces, have been ubiquitously adopted in our daily life, especially in consumer electronics and numerous industrial applications. However, the lack of sensing the force information in conventional TSPs draws compromises in gesture strategies and user experiences, leading to complex gestures, multi-level menus, waiting and so on. This paper investigated a piezoresistive tactile sensor array, which sensed the force amplitude of a touch event with the location information using four tactile cells. The development of the sensor array prototype has been discussed, including the design, fabrication, packaging, and tests. Each sensor in the array was tested, demonstrating the sensitivity of 0.31 mV/mN in the normal direction. The responses of the sensor array to a 30-mN normal force at various locations along two diagonal lines have been tested, gathering high agreements with numerical solutions. The approach for quantifying the force and location information using a lookup table based on the least square method has been discussed by the probe tests with a 50-mN force in the normal direction on the sensor array. The sensor array showed the capability to achieve the location resolution of 2 mm with tested forces ranging from 0.01 to 0.25 N. The prototype of concept shed light on reducing the number of tactile cells for touchscreen applications. Further numerical analysis indicates the sensor array has the scalability for potential applications, in which a larger area of detection is needed without increasing the number of tactile cells.
Autors: Shichao Yue;Walied A. Moussa;
Appeared in: IEEE Sensors Journal
Publication date: Feb 2018, volume: 18, issue:4, pages: 1685 - 1693
Publisher: IEEE
 
» A Plug-and-Play Monitoring and Control Architecture for Disturbance Compensation in Rolling Mills
Abstract:
In modern industrial processes, production quality, system performance, process reliability, and safety issues have received considerable attention. This paper proposes a plug-and-play (PnP) monitoring and control architecture that results in a simple reliable design procedure. The proposed PnP architecture is integrated with process monitoring and control systems, by which system performance can be enhanced without modifying or replacing the existing control system. Based on the proposed PnP architecture, a PnP process monitoring and disturbance compensation for rolling mills is proposed. The performance and effectiveness of the proposed approach is demonstrated using an industrial rolling mill benchmark.
Autors: Hao Luo;Xu Yang;Minjia Krueger;Steven X. Ding;Kaixiang Peng;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Feb 2018, volume: 23, issue:1, pages: 200 - 210
Publisher: IEEE
 
» A Polynomial-Time Algorithm for Pliable Index Coding
Abstract:
In pliable index coding, we consider a server with messages and clients, where each client has as side information a subset of the messages. We seek to minimize the number of broadcast transmissions, so that each client can recover any one unknown message she does not already have. Previous work has shown that the pliable index coding problem is NP-hard and requires at most broadcast transmissions, which indicates exponential savings over the conventional index coding that requires in the worst case transmissions. In this paper, building on a decoding criterion that we propose, we first design a deterministic polynomial-time algorithm that can realize the exponential benefits, by achieving, in the worst case, a performance upper bounded by broadcast transmissions. We extend our algorithm to the -requests case, where each client requires unknown messages that she does not have, and show that our algorithm requires at most broadcast transmissions. We construct lower bound instances that require at least transmissions for linear pliable index coding and at least transmissions for the- -requests case, indicating that both our upper and lower bounds are polynomials of and differ within a factor of . We provide a probabilistic analysis over random instances and show that the required number of transmissions is almost surely , as compared with the for index coding. In addition, we show that these upper and lower bounds also hold for vector pliable index coding in the worst case instances and the random graph instances, implying that vector coding does not provide benefits in terms of these bounds. Our numerical experiments show that our algorithm outperforms existing algorithms for pliable index coding by up to 50% less transmissions.
Autors: Linqi Song;Christina Fragouli;
Appeared in: IEEE Transactions on Information Theory
Publication date: Feb 2018, volume: 64, issue:2, pages: 979 - 999
Publisher: IEEE
 
» A Power-Efficient Reconfigurable OTA-C Filter for Low-Frequency Biomedical Applications
Abstract:
A power-efficient operational-transconductance-amplifier-capacitor (OTA-C) filter for biomedical applications is presented with detailed noise analysis. This filter consists of a cascade of biquadratic sections, each of which is configured via a serial-peripheral-interface circuit embedded with non-volatile memories to provide low pass or bandpass response. All filter parameters, including the gains, natural frequency, and quality factor, are orthogonally adjustable by programming charges on floating-gate bias transistors. The reconfigurable biquadratic section is composed of four power-efficient linearized OTAs. Each OTA consists of complementary hextuple-diffusor-quadruple-differential-pairs (HDQDPs) and a floating-gate common-mode feedback scheme. A developed computer algorithm for transistor dimension optimization is adopted to extend the input linear range of the HDQDP based on nonlinearity cancellation. A prototype chip is designed and fabricated in a CMOS process to demonstrate reconfigurability and performance of the proposed filter. Each biquadratic section occupies with a frequency tuning range more than five decades. Measured spurious-free dynamic ranges (SFDR) at the low pass and bandpass outputs from one of the biquadratic sections are 52.6 and 54.55 dB, respectively, when the natural frequency is programmed at 2 kHz with power consumption of 107.2 nW. A fourth-order Chebyshev low pass and an eighth-order Butterworth bandpass responses are implemented with characterized SFDRs of 50.43 and 48.3 dB, respectively.
Autors: Sheng-Yu Peng;Yu-Hsien Lee;Tzu-Yun Wang;Hui-Chun Huang;Min-Rui Lai;Chiang-Hsi Lee;Li-Han Liu;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 543 - 555
Publisher: IEEE
 
» A Preamble Collision Resolution Scheme via Tagged Preambles for Cellular IoT/M2M Communications
Abstract:
In this paper, we propose a preamble (PA) collision resolution (PACR) scheme based on multiple timing advance (TA) values captured via tagged PAs. In the proposed PACR scheme, tags are embedded in random access (RA) PAs and multiple TA values are captured for a single detected PA during a tag detection procedure. The proposed PACR scheme significantly improves RA success probability for stationary machine nodes since the nodes using collided PAs can successfully complete the corresponding RAs using exclusive data resource blocks.
Autors: Han Seung Jang;Su Min Kim;Hong-Shik Park;Dan Keun Sung;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1825 - 1829
Publisher: IEEE
 
» A Prediction Backed Model for Quality Assessment of Screen Content and 3-D Synthesized Images
Abstract:
In this paper, we address problems associated with free-energy-principle-based image quality assessment (IQA) algorithms for objectively assessing the quality of Screen Content (SC) and three-dimensional (3-D) synthesized images and also propose a very fast and efficient IQA algorithm to address these issues. These algorithms separate an image into predicted and disorder residual parts and assume disorder residual part does not contribute much to the overall perceptual quality. These algorithms fail for quality estimation of SC images as information of textual regions in SC images are largely separated into the disorder residual part and less information in the predicted part and subsequently, given a negligible emphasis. However, this is in contrast with the characteristics of human vision. Since our eyes are well trained to detect text in daily life. So, our human vision has prior information about text regions and can sense small distortions in these regions. In this paper, we proposed a new reduced-reference IQA algorithm for SC images based upon a more perceptually relevant prediction model and distortion categorization, which overcomes problems with existing free-energy-principle-based predictors. From experiments, it is validated that the proposed model has a better capability of efficiently estimating the quality of SC images as compared to the recently developed reduced-reference IQA algorithms. We also applied the proposed algorithm to judge the quality of 3-D synthesized images and observed that it even achieves better performance than the full-reference IQA metrics specifically designed for the 3-D synthesized views.
Autors: Vinit Jakhetiya;Ke Gu;Weisi Lin;Qiaohong Li;Sunil Prasad Jaiswal;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Feb 2018, volume: 14, issue:2, pages: 652 - 660
Publisher: IEEE
 
» A Probabilistic Framework for Structural Analysis and Community Detection in Directed Networks
Abstract:
There is growing interest in structural analysis of directed networks. Two major points that need to be addressed are: 1) a formal and precise definition of the graph clustering and community detection problem in directed networks and 2) algorithm design and evaluation of community detection algorithms in directed networks. Motivated by these, we develop a probabilistic framework for structural analysis and community detection in directed networks based on our previous work in undirected networks. By relaxing the assumption from symmetric bivariate distributions in our previous work to bivariate distributions that have the same marginal distributions in this paper, we can still formally define various notions for structural analysis in directed networks, including centrality, relative centrality, community, and modularity. We also extend three commonly used community detection algorithms in undirected networks to directed networks: the hierarchical agglomerative algorithm, the partitional algorithm, and the fast unfolding algorithm. These are made possible by two modularity preserving and sparsity preserving transformations. In conjunction with the probabilistic framework, we show these three algorithms converge in a finite number of steps. In particular, we show that the partitional algorithm is a linear time algorithm for large sparse graphs. Moreover, the outputs of the hierarchical agglomerative algorithm and the fast unfolding algorithm are guaranteed to be communities. These three algorithms can also be extended to general bivariate distributions with some minor modifications. We also conduct various experiments by using two sampling methods in directed networks: 1) PageRank and 2) random walks with self-loops and backward jumps.
Autors: Cheng-Shang Chang;Duan-Shin Lee;Li-Heng Liou;Sheng-Min Lu;Mu-Huan Wu;
Appeared in: IEEE/ACM Transactions on Networking
Publication date: Feb 2018, volume: 26, issue:1, pages: 31 - 46
Publisher: IEEE
 
» A Probabilistic Framework for Tracking the Formation and Evolution of Multi-Vehicle Groups in Public Traffic in the Presence of Observation Uncertainties
Abstract:
Future self-driving cars and current ones with advanced driver assistance systems are expected to interact with other traffic participants, which often are multiple other vehicles. Object vehicle tracking forms a key part of resolving this interaction. Furthermore, descriptions of the vehicle group behaviors, like group formations or splits, can enhance the utility of the tracking information for further motion planning and control decisions. In this paper, we propose a probabilistic method to estimate the formation and evolution, including splitting, re-grouping, and so on, of object vehicle groups and the membership conditions for individual object vehicles forming the groups. A Bayesian estimation approach is used to first estimate the states of the individual vehicles in the presence of uncertainties due to sensor imperfections and other disturbances acting on the individual object vehicles. The closeness of the individual vehicles in both their positions and velocity is then evaluated by a probabilistic collision condition. Based on this, a density-based clustering approach is applied to identify the vehicle groups as well as the identity of the individual vehicles in each group. An estimation of the state of the group as well as of the group boundary is also given. Finally, detailed numerical experiments are included, including one on real-time traffic intersection data, to illustrate the workings and the performance of the proposed approach. The potential application of the approach in motion planning of autonomous vehicles is also highlighted.
Autors: Qian Wang;Beshah Ayalew;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Feb 2018, volume: 19, issue:2, pages: 560 - 571
Publisher: IEEE
 
» A Pulse Frequency Modulation Interpretation of VCOs Enabling VCO-ADC Architectures With Extended Noise Shaping
Abstract:
In this paper, we propose to study voltage controlled oscillators (VCOs) based on the equivalence with pulse frequency modulators (PFMs). This approach is applied to the analysis of VCO-based analog-to-digital converters (VCO-ADCs) and deviates significantly from the conventional interpretation, where VCO-ADCs have been described as the first-order modulators. A first advantage of our approach is that it unveils systematic error components not described by the equivalence with a conventional modulator. A second advantage is that, by a proper selection of the pulses generated by the PFM, we can theoretically construct an open loop VCO-ADC with an arbitrary noise shaping order. Unfortunately, with the exception of the first-order noise shaping case, the required pulse waveforms cannot easily be implemented on the circuit level. However, we describe circuit techniques to achieve a good approximation of the required pulse waveforms, which can easily be implemented by practical circuits. Finally, our approach enables a straightforward description of multistage modulator architectures, which is an alternative and practically feasible way to realize a VCO-ADC with extended noise shaping.
Autors: Eric Gutierrez;Luis Hernandez;Fernando Cardes;Pieter Rombouts;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 444 - 457
Publisher: IEEE
 
» A PV Residential Microinverter With Grid-Support Function: Design, Implementation, and Field Testing
Abstract:
Microinverter-based photovoltaic (PV) systems now represent about 8% of the U.S. residential market, and offer many advantages including safety, performance, and simplified installation. The next-generation of PV microinverter will include more ancillary functions to support grid stability and reliability in more distributed generation smart-grid systems. A commercial ready PV microinverter not only focuses on efficiency and cost, but also on reliability, manufacturability, compliance of various grid-code, and electromagnetic interference regulations. This paper presents a detailed design and development process of a microinverter system from concept all the way to final commercial-ready prototype. Various design tradeoffs such as topology, control, filter solutions and power supplies, and mechanical packaging are provided. The required prototype testing and final system field tests are also presented. The presented design and test process intends to accelerate the future microinverter system design and development toward a commercial ready product.
Autors: Dong Dong;Mohammed S. Agamy;Maja Harfman-Todorovic;Xiaohu Liu;Luis Garces;Rui Zhou;Philip Cioffi;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 469 - 481
Publisher: IEEE
 
» A QCM Sensor Array-Based Electronic Tongue With the Optimized Oscillator Circuit Using FPGA
Abstract:
In this paper, an electronic tongue (ET) based on a quartz-crystal microbalance (QCM) sensor array was designed and the methods for sensor data analysis were described. In this regard, as chemical sensors, QCM crystals coated with three different phthalocyanines were employed to discriminate toxic chemicals in liquid media. For sensors’ preparation, an automatic coating instrument was developed based on the airbrush technique. The oscillator circuits used in the coating instrument and measurement setup were optimized to minimize the noise and mutual interference of the other oscillator circuits in the sensor array. The designed measurement system, which was responsible for collecting and storing data, communicating with a computer, consisted of a field-programmable gate-array-based control unit. The measurement system collected training data from the sensor array, and then computer application using MATLAB used an artificial neural network to find the composition of toxic chemicals in the sample water. The measurement system was tested for three different toxic chemicals, and the average success rate in predicting them was 4.08%. The desired chemicals can be detectable by preparing the necessary sensor array with the proposed ET.
Autors: Fırat Aydemir;Mehmet Ali Ebeoğlu;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Feb 2018, volume: 67, issue:2, pages: 431 - 438
Publisher: IEEE
 
» A Randomized Algorithm for Parsimonious Model Identification
Abstract:
Identifying parsimonious models is generically a “hard” nonconvex problem. Available approaches typically rely on relaxations such as Group Lasso or nuclear norm minimization. Moreover, incorporating stability and model order constraints into the formalism in such methods entails a substantial increase in computational complexity. Motivated by these challenges, in this paper we present algorithms for parsimonious linear time invariant system identification aimed at identifying low-complexity models which i) incorporate a priori knowledge on the system (e.g., stability), ii) allow for data with missing/nonuniform measurements, and iii) are able to use data obtained from several runs of the system with different unknown initial conditions. The randomized algorithms proposed are based on the concept of atomic norm and provide a numerically efficient way to identify sparse models from large amounts of noisy data.
Autors: Burak Yılmaz;Korkut Bekiroglu;Constantino Lagoa;Mario Sznaier;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Feb 2018, volume: 63, issue:2, pages: 532 - 539
Publisher: IEEE
 
» A Rationale for Acceleration Feedback in Force Control of Series Elastic Actuators
Abstract:
Series elastic actuators (SEAs) have become fundamental components in robots that physically interact with unstructured environments and humans. Force control of SEAs is indeed an active area of research. This paper proposes a theoretical foundation for acceleration feedback (AF) in SEA force control. Even if AF already appeared in early works on SEAs, its advantages have not been properly highlighted in the literature. In particular, this paper formally motivates improved performance robustness and transparency exactly as if using a softer and lighter actuator. Taking advantage of AF, we propose a generic control architecture characterized by impressive performance robustness in spite of even high environment uncertainties. A comparison with state-of-the-art force control solutions such as disturbance observers and adaptive controllers is reported using a comprehensive set of simulations and experiments. As a result, AF methods exhibit the higher performance robustness and accuracy. Beside this outcome, AF controllers are extremely easy to implement and the rise of low-cost miniaturized accelerometers based on micro electro-mechanical systems (MEMS) represents an additional motivations for their use.
Autors: Andrea Calanca;Paolo Fiorini;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 48 - 61
Publisher: IEEE
 
» A Real-Time Heterogeneous Emulator of a High-Fidelity Utility-Scale Variable-Speed Variable-Pitch Wind Turbine
Abstract:
Wind energy has the highest development rates of renewables. The increasing complexity of wind turbine (WT) systems requires careful analysis and design with thorough testing and certification procedures. Hardware emulators contribute to safe and cost-effective assessment and testing of WT in research and industry. Most of the available emulators concentrate on emulating electrical subsystems with simplified mechanical models. In this paper, a real-time (RT) heterogeneous emulator that combines RT discrete-time step simulation and a high-fidelity linear parameter-varying model of a utility-scale WT system is proposed and implemented on a heterogeneous CPU/GPU platform. The RT emulator is built on an embedded NVIDIA Jetson TK1 board for a National Renewable Energy Laboratory 5-MW WT as a case study. The proposed emulator is capable of further integration of electrical models and control systems of WT.
Autors: Mohammed Moness;Muhammad Osama Mahmoud;Ahmed Mahmoud Moustafa;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Feb 2018, volume: 14, issue:2, pages: 437 - 447
Publisher: IEEE
 
» A Regression-Based High-Pass Modulation Pansharpening Approach
Abstract:
Pansharpening usually refers to the fusion of a high spatial resolution panchromatic (PAN) image with a higher spectral resolution but coarser spatial resolution multispectral (MS) image. Owing to the wide applicability of related products, the literature has been populated by many papers proposing several approaches and studies about this issue. Many solutions require a preliminary spectral matching phase wherein the PAN image is matched with the MS bands. In this paper, we propose and properly justify a new approach for performing this step, demonstrating that it yields state-of-the-art performance. The comparison with existing spectral matching procedures is performed by employing four data sets, concerning different kinds of landscapes, acquired by the Pléiades, WorldView-2, and GeoEye-1 sensors.
Autors: Gemine Vivone;Rocco Restaino;Jocelyn Chanussot;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 984 - 996
Publisher: IEEE
 
» A Ring Oscillator-Based Identification Mechanism Immune to Aging and External Working Conditions
Abstract:
Physically unclonable functions (PUFs) are one of the most important breakthrough for security of devices as they represent a low-cost means to provide authentication and secure storage. PUFs measure nano-scale mismatches that are inherently caused by the manufacturing process. However, the mechanisms exploited by PUF circuits depend on the working conditions, such as temperature, device aging, and current flow, making them unreliable and, hence preventing their wider employment. One of the most investigated PUF exploits pairs of ring oscillators (ROs): frequencies measured from each pair are compared for extracting one response bit. However, extracted bit-strings are not suitable for authentication purposes as they may change during time. In this paper, we propose a new identification mechanism, based on ROs, which is immune to aging and working conditions. Through a mathematical demonstration and an extensive experimental campaign, which involved real field programmable gate array devices, we demonstrate its ability to reliably accomplish identification of silicon devices.
Autors: Mario Barbareschi;Giorgio Di Natale;Lionel Torres;Antonino Mazzeo;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 700 - 711
Publisher: IEEE
 
» A Robust and Efficient Algorithm for Coprime Array Adaptive Beamforming
Abstract:
Coprime array offers a larger array aperture than uniform linear array with the same number of physical sensors, and has a better spatial resolution with increased degrees of freedom. However, when it comes to the problem of adaptive beamforming, the existing adaptive beamforming algorithms designed for the general array cannot take full advantage of coprime feature offered by the coprime array. In this paper, we propose a novel coprime array adaptive beamforming algorithm, where both robustness and efficiency are well balanced. Specifically, we first decompose the coprime array into a pair of sparse uniform linear subarrays and process their received signals separately. According to the property of coprime integers, the direction-of-arrival (DOA) can be uniquely estimated for each source by matching the super-resolution spatial spectra of the pair of sparse uniform linear subarrays. Further, a joint covariance matrix optimization problem is formulated to estimate the power of each source. The estimated DOAs and their corresponding power are utilized to reconstruct the interference-plus-noise covariance matrix and estimate the signal steering vector. Theoretical analyses are presented in terms of robustness and efficiency, and simulation results demonstrate the effectiveness of the proposed coprime array adaptive beamforming algorithm.
Autors: Chengwei Zhou;Yujie Gu;Shibo He;Zhiguo Shi;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1099 - 1112
Publisher: IEEE
 
» A Robust Dynamic Edge Network Architecture for the Internet of Things
Abstract:
A massive number of devices are expected to fulfill the missions of sensing, processing and control in cyber-physical IoT systems with new applications and connectivity requirements. In this context, scarce spectrum resources must accommodate high traffic volume with stringent requirements of low latency, high reliability, and energy efficiency. Conventional centralized network architectures may not be able to fulfill these requirements due to congestion in backhaul links. This article presents a novel design of an RDNA for IoT that leverages the latest advances of mobile devices (e.g., their capability to act as access points, storing and computing capabilities) to dynamically harvest unused resources and mitigate network congestion. However, traffic dynamics may compromise the availability of terminal access points and channels, and thus network connectivity. The proposed design embraces solutions at the physical, access, networking, application, and business layers to improve network robustness. The high density of mobile devices provides alternatives for close connectivity, reducing interference and latency, and thus increasing reliability and energy efficiency. Moreover, the computing capabilities of mobile devices project smartness onto the edge, which is desirable for autonomous and intelligent decision making. A case study is included to illustrate the performance of RDNA. Potential applications of this architecture in the context of IoT are outlined. Finally, some challenges for future research are presented.
Autors: Beatriz Lorenzo;Juan Garcia-Rois;Xuanheng Li;Javier Gonzalez-Castano;Yuguang Fang;
Appeared in: IEEE Network
Publication date: Feb 2018, volume: 32, issue:1, pages: 8 - 15
Publisher: IEEE
 
» A Robust Multibit Multiplicative Watermark Decoder Using a Vector-Based Hidden Markov Model in Wavelet Domain
Abstract:
The vector-based hidden Markov model (HMM) is a powerful statistical model for characterizing the distribution of the wavelet coefficients, since it is capable of capturing the subband marginal distribution as well as the inter-scale and cross-orientation dependencies of the wavelet coefficients. In this paper we propose a scheme for designing a blind multibit watermark decoder incorporating the vector-based HMM in wavelet domain. The decoder is designed based on the maximum likelihood criterion. A closed-form expression is derived for the bit error rate and validated experimentally with Monte Carlo simulations. The performance of the proposed watermark detector is evaluated using a set of standard test images and shown to outperform the decoders designed based on the Cauchy or generalized Gaussian distributions without or with attacks. It is also shown that the proposed decoder is more robust against various kinds of attacks compared with the state-of-the-art methods.
Autors: Marzieh Amini;M. Omair Ahmad;M.N.S. Swamy;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Feb 2018, volume: 28, issue:2, pages: 402 - 413
Publisher: IEEE
 
» A Scalable In-Memory Logic Synthesis Approach Using Memristor Crossbar
Abstract:
Because of their resistive switching properties and ease of controlling the resistive states, memristors have been proposed in nonvolatile storage as well as logic design applications. Memristors can be fabricated in a crossbar and suitable voltages applied to the row and column nanowires to control their states. This makes it possible to move toward new non-von Neumann-type architectures, usually referred to as in-memory computing, where logic operations can be performed directly on the storage fabric. In this paper, a scalable design flow for in-memory computing has been proposed, where a given multioutput logic function is synthesized as a netlist of NOT/NOR gates and then mapped to the crossbar using the Memristor-Aided loGIC (MAGIC) design style. The memristors corresponding to the primary inputs are initialized a priori. Subsequently, the required gate operations are performed by applying suitable row and column voltages in sequence. Two alternate mapping schemes have been analyzed. The switching characteristics of MAGIC NOR gates have been evaluated using circuit simulation under the Cadence Virtuoso environment. Experimental evaluation on ISCAS’85 benchmarks reports the average improvements of 27.7%, 34.6%, and 26.2%, respectively over a recently published work with respect to the number of memristors, number of cycles, and total energy dissipation, respectively. It may be noted that the energy consumption of the gates used in the proposed approach (NOT and NOR) is significantly higher than that using CMOS technology.
Autors: Rahul Gharpinde;Phrangboklang Lynton Thangkhiew;Kamalika Datta;Indranil Sengupta;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Feb 2018, volume: 26, issue:2, pages: 355 - 366
Publisher: IEEE
 
» A Scalable Multicore Architecture With Heterogeneous Memory Structures for Dynamic Neuromorphic Asynchronous Processors (DYNAPs)
Abstract:
Neuromorphic computing systems comprise networks of neurons that use asynchronous events for both computation and communication. This type of representation offers several advantages in terms of bandwidth and power consumption in neuromorphic electronic systems. However, managing the traffic of asynchronous events in large scale systems is a daunting task, both in terms of circuit complexity and memory requirements. Here, we present a novel routing methodology that employs both hierarchical and mesh routing strategies and combines heterogeneous memory structures for minimizing both memory requirements and latency, while maximizing programming flexibility to support a wide range of event-based neural network architectures, through parameter configuration. We validated the proposed scheme in a prototype multicore neuromorphic processor chip that employs hybrid analog/digital circuits for emulating synapse and neuron dynamics together with asynchronous digital circuits for managing the address-event traffic. We present a theoretical analysis of the proposed connectivity scheme, describe the methods and circuits used to implement such scheme, and characterize the prototype chip. Finally, we demonstrate the use of the neuromorphic processor with a convolutional neural network for the real-time classification of visual symbols being flashed to a dynamic vision sensor (DVS) at high speed.
Autors: Saber Moradi;Ning Qiao;Fabio Stefanini;Giacomo Indiveri;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Feb 2018, volume: 12, issue:1, pages: 106 - 122
Publisher: IEEE
 
» A Self-Adaptive Online Brain–Machine Interface of a Humanoid Robot Through a General Type-2 Fuzzy Inference System
Abstract:
This paper presents a self-adaptive autonomous online learning through a general type-2 fuzzy system (GT2 FS) for the motor imagery (MI) decoding of a brain-machine interface (BMI) and navigation of a bipedal humanoid robot in a real experiment, using electroencephalography (EEG) brain recordings only. GT2 FSs are applied to BMI for the first time in this study. We also account for several constraints commonly associated with BMI in real practice: 1) the maximum number of EEG channels is limited and fixed; 2) no possibility of performing repeated user training sessions; and 3) desirable use of unsupervised and low-complexity feature extraction methods. The novel online learning method presented in this paper consists of a self-adaptive GT2 FS that can autonomously self-adapt both its parameters and structure via creation, fusion, and scaling of the fuzzy system rules in an online BMI experiment with a real robot. The structure identification is based on an online GT2 Gath–Geva algorithm where every MI decoding class can be represented by multiple fuzzy rules (models), which are learnt in a continous (trial-by-trial) non-iterative basis. The effectiveness of the proposed method is demonstrated in a detailed BMI experiment, in which 15 untrained users were able to accurately interface with a humanoid robot, in a single session, using signals from six EEG electrodes only.
Autors: Javier Andreu-Perez;Fan Cao;Hani Hagras;Guang-Zhong Yang;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Feb 2018, volume: 26, issue:1, pages: 101 - 116
Publisher: IEEE
 
» A Semi-Anaytical Model for the Analysis of a Permanent Magnet Tubular Linear Generator
Abstract:
In this paper, the authors introduce a semianalytical model for the analysis and the design of a permanent magnet (PM) tubular linear generator intended for electrical energy generation from sea waves. The translator of the analyzed machine is constituted by axially magnetized ferrite PMs with alternating polarity and soft magnetic pole pieces in between; a two-pole, double-layer, three-phase winding is located in the slots of the stator. The presented model, based on the use of the Carter coefficient and of the Fourier transform in the direction of the motion, is able to take into account the end effects due to the finite length of the stator. The presence of slots and teeth is subsequently considered by some postprocessing calculation carried on the results of the semianalytical model. Comparison with a finite element analysis and measurements taken on a prototype has been performed to validate the presented model. The model can be easily extended to other translator typologies, e.g., to air core translator with Halbach array of NdFeB PMs.
Autors: Antonino Musolino;Marco Raugi;Rocco Rizzo;Luca Sani;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 204 - 212
Publisher: IEEE
 
» A Sensitive Dynamic and Active Pixel Vision Sensor for Color or Neural Imaging Applications
Abstract:
Applications requiring detection of small visual contrast require high sensitivity. Event cameras can provide higher dynamic range (DR) and reduce data rate and latency, but most existing event cameras have limited sensitivity. This paper presents the results of a 180-nm Towerjazz CIS process vision sensor called SDAVIS192. It outputs temporal contrast dynamic vision sensor (DVS) events and conventional active pixel sensor frames. The SDAVIS192 improves on previous DAVIS sensors with higher sensitivity for temporal contrast. The temporal contrast thresholds can be set down to 1% for negative changes in logarithmic intensity (OFF events) and down to 3.5% for positive changes (ON events). The achievement is possible through the adoption of an in-pixel preamplification stage. This preamplifier reduces the effective intrascene DR of the sensor (70 dB for OFF and 50 dB for ON), but an automated operating region control allows up to at least 110-dB DR for OFF events. A second contribution of this paper is the development of characterization methodology for measuring DVS event detection thresholds by incorporating a measure of signal-to-noise ratio (SNR). At average SNR of 30 dB, the DVS temporal contrast threshold fixed pattern noise is measured to be 0.3%–0.8% temporal contrast. Results comparing monochrome and RGBW color filter array DVS events are presented. The higher sensitivity of SDAVIS192 make this sensor potentially useful for calcium imaging, as shown in a recording from cultured neurons expressing calcium sensitive green fluorescent protein GCaMP6f.
Autors: Diederik Paul Moeys;Federico Corradi;Chenghan Li;Simeon A. Bamford;Luca Longinotti;Fabian F. Voigt;Stewart Berry;Gemma Taverni;Fritjof Helmchen;Tobi Delbruck;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Feb 2018, volume: 12, issue:1, pages: 123 - 136
Publisher: IEEE
 
» A Sensor-Assisted Emergency Guiding System: Sensor-Centric or User-Centric?
Abstract:
The goal of sensor-assisted emergency guiding systems is to guide people to exits as soon as possible in emergencies (e.g., fires in buildings). Sensors are deployed in a smart environment to monitor and detect hazards. Sensors collaborate with each other to compute guiding paths for people in case of emergencies. To achieve this goal, this paper focuses on the sensor-assisted guiding problem, which studies how to guide people to exits quickly. Thus, the sensor-assisted guiding problem is analyzed from two different aspects: the sensor-centric guiding problem and the user-centric guiding problem. The former is to find a guiding direction for each single sensor for evacuating people nearby, whereas the latter is to find a personalized guiding direction for each individual user. In other words, the number of guiding directions provided by each single sensor in the sensor-centric guiding problem is limited, whereas this constraint is relaxed in the user-centric guiding problem. This paper proves that the sensor-centric guiding problem is NP-hard. When the constraint is relaxed, a user-centric guiding system is more efficient. Then, this paper designs a localized user-centric guiding protocol, which allows each sensor to provide more than one guiding direction for personalized guiding. The key idea of the proposed protocol is to estimate the evacuation time in a distributed manner. Extensive simulation results show that the proposed solution can significantly reduce the evacuation time by compared to typical sensor-centric approaches. Finally, the implemented prototype indicates that proposed protocol is lightweight and can work with real sensor platforms.
Autors: Fang-Jing Wu;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1598 - 1611
Publisher: IEEE
 
» A Silicon-Based Low-Power Broadband Transimpedance Amplifier
Abstract:
The analysis, design, and implementation of a 50-Gb/s transimpedance amplifier (TIA) in a 0.13- SiGe BiCMOS process are presented. The proposed TIA, designed for use in a single-channel optical communication network, is comprised of three stages including: 1) a shunt-peaked, shunt-series feedback stage incorporating a transformer-based positive feedback; 2) an -degenerated common-emitter stage; and 3) an inductively degenerated emitter follower. The TIA chip integrates an on-chip 100-fF input capacitor to emulate the photo-detector junction capacitor, and achieves a measured transimpedance gain of 41 dB and an input-referred current-noise spectral density of 39.8 pA/ over a 50-GHz bandwidth. The TIA achieves an open eye at 50 Gbps with random jitter of 2.3-ps rms (including the jitter contribution of the test fixture). The prototype chip occupies 0.58 mm2 (including pads) of die area and dissipates 24 mW of dc power from a 2-V supply voltage (i.e., less than 0.5 pJ/bit).
Autors: Alireza Karimi-Bidhendi;Hossein Mohammadnezhad;Michael M. Green;Payam Heydari;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 498 - 509
Publisher: IEEE
 
» A Simple Tri-Polarization Reconfigurable Magneto-Electric Dipole Antenna
Abstract:
A simple magneto-electric (ME) dipole antenna with reconfigurable polarizations has been designed. The proposed ME dipole antenna mainly comprises three pairs of horizontal rectangular patches, a Γ-shaped feed, a metallic cavity, and four PIN diodes. By independently controlling the on/off state of the PIN diodes, the horizontal rectangular patches can be connected/disconnected, thus exhibiting linear polarization, right-hand circular polarization, and left-hand circular polarization. The experimental results demonstrate that the proposed ME dipole antenna has a wide effective bandwidth of 33.9% from 1.74 to 2.45 GHz for both S11 ≤ −10 dB and axial ratio ≤3 in all polarization states, and a stable gain of 8.2 ± 0.8 dBi. Good unidirectional radiation characteristic and low backlobe level are achieved over the whole operating frequency band. A prototype was fabricated, and good agreement between measured and simulated results validates polarization diversity of the proposed antenna.
Autors: Yan Shi;Yi Cai;Xiang-Fan Zhang;Kai Kang;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 291 - 294
Publisher: IEEE
 
» A Simplified FRI Sampling System for Pulse Streams Based on Constraint Random Modulation
Abstract:
The recent finite rate of innovation (FRI) framework provides effective sub-Nyquist sampling of pulse streams, allowing recovery of such signals from a set of Fourier coefficients. In this brief, a multi-channel FRI sampling system is presented to sample distinct bands of Fourier coefficients. This is achieved through modulating the desired spectrum band to baseband and then filtering with a low-pass filter. However, the modulation process will lead to the spectrum aliasing and unavailability. A modulation frequency selection strategy is proposed to solve this problem, which allows obtaining reconfigurable Fourier coefficients from the aliasing spectrum. Combining with multi-channel structure, we present a simple and efficient way to sample distinct bands of the pulse streams’ spectrum. Finally, a design and implementation of the hardware prototype is presented. Simulation and hardware experiment results demonstrate the effectiveness and robustness of our system.
Autors: Guoxing Huang;Ning Fu;Liyan Qiao;Jie Cao;Chuanzhi Fan;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Feb 2018, volume: 65, issue:2, pages: 256 - 260
Publisher: IEEE
 
» A Simplified Photonic Approach to Measuring the Microwave Doppler Frequency Shift
Abstract:
A novel approach for measuring the microwave Doppler frequency shift (DFS) based on a dual-drive Mach-Zehnder modulator (DDMZM) is proposed and demonstrated. The value and direction of the DFS can be simultaneously measured with high precision by using a reference signal. In the DDMZM, the transmitted signal and reference signal are applied to one radio frequency (RF) port, while the echo signal is applied to the other RF port. Then, the generated optical signals are sent to a low-speed photodetecter, and the beat frequency between the transmitted and echo signals is equal to the value of DFS, while the direction of DFS can be distinguished by comparing the two beat frequencies generated by the transmitted signal with reference signal and the echo signal with reference signal, respectively. The DFS from -100 to +100 kHz at the carrier frequency of 10, 14, and 18 GHz is successfully measured, and the maximal error is less than 1.0 Hz.
Autors: Lu Xu;Yuan Yu;Haitao Tang;Xinliang Zhang;
Appeared in: IEEE Photonics Technology Letters
Publication date: Feb 2018, volume: 30, issue:3, pages: 246 - 249
Publisher: IEEE
 
» A Single Color Camera Stereo Vision System
Abstract:
In this paper, a novel single color camera stereo vision system is proposed. Two planar mirrors are used to create double views (blue and red views). A dichroic filter (DF) is used to combine them and eliminate their interference. The double views can then be captured by a color camera through blue and red channels. When the DF transmits the red light, refraction would occur. During calibration, we separate the calibration process: calibrate the virtual red camera and the virtual blue camera in order, and then calibrate their pose relationship. The refraction is removed in this process. Moreover, when computing the 3-D position of a point, the measurement error caused by the refraction is also considered. In this experiment, the interference between the blue- and red-channels is shown to be negligible. We verified the proposed vision system on the standard spherical and cylindrical surfaces. It is shown that the measurement accuracy is improved when the effect of refraction is considered. In addition, the noise robustness of this proposed system is also tested. The measurement accuracy would not be affected severely, if the standard deviation of the uniformly distributed random noise is less than 0.035. Finally, the proposed system is employed to measure the profile of a flower model. The proposed system has potential industrial applications.
Autors: Fuqiang Zhong;Chenggen Quan;
Appeared in: IEEE Sensors Journal
Publication date: Feb 2018, volume: 18, issue:4, pages: 1474 - 1482
Publisher: IEEE
 
» A Single Layer 3-D Touch Sensing System for Mobile Devices Application
Abstract:
Touch sensing has been widely implemented as a main methodology to bridge human and machine interactions. The traditional touch sensing range is 2-D and therefore limits the user experience. To overcome these limitations, we propose a novel 3-D contactless touch sensing called Airtouch system, which improves user experience by remotely detecting single/multi-finger position. A single layer touch panel with triangle-shaped electrodes is proposed to achieve multitouch detection capability as well as manufacturing cost reduction. Moreover, an oscillator-based-capacitive touch sensing circuit is implemented as the sensing hardware with the bootstrapping technique to eliminate the interchannel coupling effects. To further improve the system accuracy, a grouping algorithm is proposed to group the useful channels’ data and filter out hardware noise impact. Finally, improved algorithms are proposed to eliminate the fringing capacitance effect and achieve accurate finger position estimation. EM simulation proved that the proposed algorithm reduced the maximum systematic error by 11 dB in the horizontal position detection. The proposed system consumes 2.3 mW and is fully compatible with existing mobile device environments. A prototype is built to demonstrate that the system can successfully detect finger movement in a vertical direction up to 6 cm and achieve a horizontal resolution up to 0.6 cm at 1 cm finger-height. As a new interface for human and machine interactions, this system offers great potential in finger movement detection and gesture recognition for small-sized electronics and advanced human interactive games for mobile device.
Autors: Li Du;Chun-Chen Liu;Yan Zhang;Yilei Li;Yuan Du;Yen-Cheng Kuan;Mau-Chung Frank Chang;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Feb 2018, volume: 37, issue:2, pages: 286 - 296
Publisher: IEEE
 
» A Single-Point, Multiparameter, Fiber Optic Sensor Based on a Combination of Interferometry and LSPR
Abstract:
We demonstrate a new single-point, multiparameter, fiber optic sensor concept based on a combination of interferometric and plasmonic sensor modalities on an optical fiber end face. The sensor consists of an extrinsic Fabry–Perot interferometer in the form of a hemispherical stimuli-responsive hydrogel with immobilized gold nanoparticles (GNPs). The GNPs exhibit local surface plasmon resonance (LSPR) that is sensitive toward the local refractive index (RI) of the surrounding environment, whereas the stimuli-responsive hydrogel is sensitive toward specific chemical compounds. We evaluate the quality of the interferometric and LSPR signals as a function of GNP concentration and of hydrogel swelling degree stimulated by ethanol solutions. The GNPs have little influence on the visibility of the Fabry–Perot etalon. The swelling degree of the hydrogel, with corresponding bulk RI changes, has little influence on the local surface RI of the GNPs. We expect this novel sensor concept to be of great value for biosensors for medical applications.
Autors: Harald Ian Muri;Andon Bano;Dag Roar Hjelme;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2018, volume: 36, issue:4, pages: 1159 - 1167
Publisher: IEEE
 
» A Smooth EKV-Based DC Model for Accurate Simulation of Printed Transistors and Their Process Variations
Abstract:
A printed electronics technology has the advantage of additive and extremely low-cost fabrication compared with the conventional silicon technology. Specifically, printed electrolyte-gated field-effect transistors (EGFETs) are attractive for low-cost applications in the Internet-of-Things domain as they can operate at low supply voltages. In this paper, we propose an empirical dc model for EGFETs, which can describe the behavior of the EGFETs smoothly and accurately over all regimes. The proposed model, built by extending the Enz–Krummenacher–Vittoz model, can also be used to model process variations, which was not possible previously due to fixed parameters for near threshold regime. It offers a single model for all the operating regions of the transistors with only one equation for the drain current. Additionally, it models the transistors with a less number of parameters but higher accuracy compared with existing techniques. Measurement results from several fabricated EGFETs confirm that the proposed model can predict the – more accurately compared with the state-of-the-art models in all operating regions. Additionally, the measurements on the frequency of a fabricated ring oscillator are only 4.7% different from the simulation results based on the proposed model using values for the switching capacitances extracted from measurement data, which shows more than improvement compared with the state-of-the-art model.
Autors: Farhan Rasheed;Mohammad Saber Golanbari;Gabriel Cadilha Marques;Mehdi B. Tahoori;Jasmin Aghassi-Hagmann;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 667 - 673
Publisher: IEEE
 
» A Software-Defined Frequency-Reconfigurable Meandered Printed Monopole
Abstract:
In this letter, a frequency-reconfigurable printed meandered monopole structure is presented. The antenna structure is composed of three radiating parts that are connected through two integrated PIN diodes. Such integration allows the antenna to reconfigure its operation within four frequency bands that correspond to various LTE, UMTS, and GSM channels. A graphical user interface (GUI) using Java is employed to control the states of the switches. The interface allows the control of a microcontroller to supply appropriate current to each of the two diodes. The GUI also simulates a cognitive radio environment where the activation of the corresponding PIN diodes is determined by the users’ activities. A prototype is fabricated and tested as a proof of concept where measured results agree with simulated data.
Autors: Y. Tawk;A. El-Amine;S. Saab;J. Costantine;F. Ayoub;C. G. Christodoulou;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 327 - 330
Publisher: IEEE
 
» A Software-Defined Multi-Element VLC Architecture
Abstract:
In the modern era of RF spectrum crunch, VLC is a recent and promising alternative technology that operates at the visible light spectrum. Thanks to its unlicensed and large bandwidth, VLC can deliver high throughput, better energy efficiency, and low-cost data communications. In this article, a hybrid RF/VLC architecture is considered that can simultaneously provide lighting and communication coverage across a room. The considered architecture involves a novel multi-element hemispherical bulb design, which can transmit multiple data streams over LED modules. Simulations considering various VLC transmitter configurations and topologies show that good link quality and high spatial reuse can be maintained in typical indoor communication scenarios.
Autors: Sifat Ibne Mushfique;Prabath Palathingal;Yusuf Said Eroglu;Murat Yuksel;Ismail Guvenc;Nezih Pala;
Appeared in: IEEE Communications Magazine
Publication date: Feb 2018, volume: 56, issue:2, pages: 196 - 203
Publisher: IEEE
 
» A Spectroscopy and Microscopy Study of Parylene-C OFETs for Explosive Sensing
Abstract:
In this paper, we have explored Parylene-C (PC) as a sensing material for its unique signature and selectivity for explosive sensing. We have used a bi-layer deposition process to fabricate bottom-gate-top-contact organic field effect transistor (OFET) structures. Opening of dangling bonds on subjecting PC to plasma oxidation (POPC) renders these molecules to be employed as a receptor material in sensing vapors of both explosives and non-explosives, such as Trinitrotoulene (TNT), 1,3,5 trinitro-1,3,5-triazacyclohexane(RDX), PETN, Dinitrobenzene (DNB), Nitrobenzene (NB), Benzoquinone (BQ), and Benzophenone (BP). The change in: 1) the vibrational modes of the molecule by infrared spectroscopy; 2) surface potential of POPC by Kelvin probe force microscopy (KPFM); and 3) electrical characterization by I–V measurements of PC-based OFET on exposing to vapors have been systematically studied. Different signatures for all the analytes have been observed while exact and perfect selectivity for TNT, RDX were found from I–V studies and for PETN by KPFM studies. Thus, the OFET device-based chemical sensors demonstrated here with improved sensitivity and excellent selectivity, stand as promising candidates for explosives detection.
Autors: Sandeep G. Surya;Sunil Kumar Samji;Pasam Dhamini;Bs Pavan Ganne;Prashant Sonar;V. Ramgopal Rao;
Appeared in: IEEE Sensors Journal
Publication date: Feb 2018, volume: 18, issue:4, pages: 1364 - 1372
Publisher: IEEE
 
» A Stable FDTD Method With Embedded Reduced-Order Models
Abstract:
The computational efficiency of the finite-difference time-domain (FDTD) method can be significantly reduced by the presence of complex objects with fine features. Small geometrical details impose a fine mesh and a reduced time step, significantly increasing computational cost. Model order reduction has been proposed as a systematic way to generate compact models for complex objects, by which one can then instantiate into a main FDTD mesh. However, the stability of FDTD with embedded reduced models remains an open problem. We propose a systematic method to generate reduced models for FDTD domains, and embed them into a main FDTD mesh with guaranteed stability up to the Courant–Friedrichs–Lewy (CFL) limit of the fine mesh. With a simple perturbation technique, the CFL of the whole scheme can be further extended beyond the fine grid’s CFL limit. Reduced models can be created for arbitrary domains containing inhomogeneous and lossy materials. Numerical tests confirm the stability of the proposed method and its potential to accelerate multiscale FDTD simulations.
Autors: Xinyue Zhang;Fadime Bekmambetova;Piero Triverio;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 827 - 837
Publisher: IEEE
 
» A Stochastic Home Energy Management System Considering Satisfaction Cost and Response Fatigue
Abstract:
Home energy management (HEM) systems enable residential consumers to participate in demand response programs (DRPs) more actively. However, HEM systems confront some practical difficulties due to the uncertainty related to renewable energies as well as the uncertainty of consumers’ behavior. Moreover, the consumers aim for the highest level of comfort and satisfaction in operating their electrical appliances. In addition, technical limits of the appliances must be considered. Furthermore, DR providers aim at keeping the participation of consumers in DRPs and minimize the “response fatigue” phenomenon in the long-term period. In this paper, a stochastic model of an HEM system is proposed by considering uncertainties of electric vehicles availability and small-scale renewable energy generation. The model optimizes the customer's cost in different DRPs, while guarantees the inhabitants’ satisfaction by introducing a response fatigue index. Different case studies indicate that the implementation of the proposed stochastic HEM system can considerably decrease both the customers’ cost and response fatigue.
Autors: Miadreza Shafie-Khah;Pierluigi Siano;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Feb 2018, volume: 14, issue:2, pages: 629 - 638
Publisher: IEEE
 
» A Suction-Fixing, Stiffness-Tunable Liver Manipulator for Laparoscopic Surgeries
Abstract:
This paper presents a novel liver manipulator featuring suction fixing, stiffness tuning, and pneumatic actuation. In a liver-manipulation process, the manipulator begins in a low-stiffness state and is then pneumatically actuated to fit suction pads to the liver surface. At this point, the manipulator vacuums external air through the suction pads to adhere to the liver surface and then turns to a high-stiffness state to hold the liver tenaciously. Stiffness tuning is achieved with two cloth-rubber beams, which are contained within a closed elastic tube. Sucking the air between the beams increases the stiffness by 4.2 times. Experimental results demonstrate liver manipulation improvement in terms of holding stability and being less invasive.
Autors: Joonhwan Kim;Yoshikazu Nakajima;Kenta Kobayashi;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Feb 2018, volume: 23, issue:1, pages: 262 - 273
Publisher: IEEE
 
» A Survey on Access Control in Fog Computing
Abstract:
Fog computing has emerged as an attractive solution to the distributed application of the Internet of Things, and could provide low-latency, highly mobile, and geo-distributed services distinguished from the cloud. While fog computing offers numerous benefits, it also faces various security challenges, of which access control is one of the fundamental requirements since it is concerned with authorizing users to access resources in the open fog environment. This article provides a comprehensive survey of access control of users' data in the environment of fog computing with the aim of highlighting security problems and challenges. It discusses the definition, architecture, and characteristics of fog computing, based on which typical requirements and essential models of access control are addressed. Finally, it highlights known access control schemes in the environment of fog computing, and identifies existing unresolved problems as future directions.
Autors: Peng Zhang;Joseph K. Liu;F. Richard Yu;Mehdi Sookhak;Man Ho Au;Xiapu Luo;
Appeared in: IEEE Communications Magazine
Publication date: Feb 2018, volume: 56, issue:2, pages: 144 - 149
Publisher: IEEE
 
» A Switchable-Frequency Slot-Ring Antenna Element for Designing a Reconfigurable Array
Abstract:
A frequency-reconfigurable slot-ring antenna switching between L- and C-bands is presented. The aperture of an L-band slot-ring antenna can be reconfigured to a 2 × 2 C -band slot-ring antenna array by changing the states of 16 p-i-n diode switches. This antenna operates at 1.76/5.71 GHz with a fractional bandwidth of 8.6%/11.5% in the L/ C-band operating states, respectively. The measured realized gain and radiation efficiency are 0.1/4.2 dBi and 66.6%/80.7%, respectively. The antenna element spacing at 5.71 GHz is 0.36λ0, which enables beamsteering without grating lobes. This shared-aperture antenna is scalable to a larger array with element spacing of less than half-wavelength in both frequency bands.
Autors: Mahmoud Shirazi;Junyi Huang;Tianjiao Li;Xun Gong;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 229 - 233
Publisher: IEEE
 
» A Switched Capacitor Energy Harvester Based on a Single-Cycle Criterion for MPPT to Eliminate Storage Capacitor
Abstract:
A single-cycle criterion maximum power point tracking (MPPT) technique is proposed to eliminate the need for bulky on-chip capacitors in the energy harvesting system for Internet of Everything (IoE). The conventional time-domain MPPT features ultra-low power consumption; however, it also requires a nanofarad-level capacitor for fine time resolution. The proposed maximum power monitoring does not rely on the time-domain, but on logic criterion that can be simply determined by a finite-state machine where the maximum photovoltaic (PV) power occurs at minimum conversion ratio and maximum switching frequency. Single-cycle is used as the criterion to determine the magnitude of the output power. Practical concerns, such as self-startup and self-sustaining capabilities are here addressed by proper design of the reconfigurable switched capacitor power converter. A hysteretic control not only regulates the output, but also avoids the loading condition in IoE applications. This harvester simultaneously addresses the challenges including self-startup, self-sustaining capability, and regulated output without using a storage capacitor. Compared with various PV cells, the power conversion efficiency has a peak value of 72%, which remains above 60% for a wide harvesting voltage and power range. The chip area is as small as 0.552 mm2.
Autors: Xiaosen Liu;Krishnan Ravichandran;Edgar Sánchez-Sinencio;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 793 - 803
Publisher: IEEE
 
» A Systems Theoretic Approach to the Security Threats in Cyber Physical Systems Applied to Stuxnet
Abstract:
Cyber physical systems (CPSs) are increasingly being adopted in a wide range of industries such as smart power grids. Even though the rapid proliferation of CPSs brings huge benefits to our society, it also provides potential attackers with many new opportunities to affect the physical world such as disrupting the services controlled by CPSs. Stuxnet is an example of such an attack that was designed to interrupt the Iranian nuclear program. In this paper, we show how the vulnerabilities exploited by Stuxnet could have been addressed at the design level. We utilize a system theoretic approach, based on prior research on system safety, that takes both physical and cyber components into account to analyze the threats exploited by Stuxnet. We conclude that such an approach is capable of identifying cyber threats towards CPSs at the design level and provide practical recommendations that CPS designers can utilize to design a more secure CPS.
Autors: Arash Nourian;Stuart Madnick;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Feb 2018, volume: 15, issue:1, pages: 2 - 13
Publisher: IEEE
 
» A Technique for Designing Multilayer Multistopband Frequency Selective Surfaces
Abstract:
A systematic technique for designing and optimizing multilayer frequency selective surfaces (FSSs) with low overall profile is presented. Periodic scatterers in the shape of loaded dipoles (dogbones) are used on each layer to create a single-stopband response. Multiple such layers are cascaded together to create the desired multistopband response. An equivalent circuit model for a multilayer FSS that explicitly and intuitively accounts for electromagnetic coupling interactions between the layers is proposed and investigated. This model is used in a novel design method, which precompensates for the effect of coupling during circuit-based design stage rather than postcompensating through iterative full-wave (FW) optimization after the design stage, as in most traditional approaches. As a consequence, this approach has the potential to greatly speed up the design process by enabling considerable simplifications during FW simulations. The proposed method is used to design several ultralow-profile triple-layer, triple-stopband surfaces intended for Wi-Fi applications. The interlayer spacing is as low as at the highest operating band (5.2 GHz), making the overall thickness extremely small. The unit cell size for the designs is about at 5.2 GHz. The designs are fabricated and tested to validate the proposed methodology.
Autors: Gengyu Xu;Sean Victor Hum;George V. Eleftheriades;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 780 - 789
Publisher: IEEE
 
» A Template-Based Design Methodology for Graph-Parallel Hardware Accelerators
Abstract:
Graph applications have been gaining importance in the last decade due to emerging big data analytics problems such as Web graphs, social networks, and biological networks. For these applications, traditional CPU and GPU architectures suffer in terms of performance and power consumption due to irregular communications, random memory accesses, and load balancing problems. It has been shown that specialized hardware accelerators can achieve much better power and energy efficiency compared to the general purpose CPUs and GPUs. In this paper, we present a template-based methodology specifically targeted for hardware accelerator design of big-data graph applications. Important architectural features that are key for energy efficient execution are implemented in a common template. The proposed template-based methodology is used to design hardware accelerators for different graph applications with little effort. Compared to an application-specific high-level synthesis methodology, we show that the proposed methodology can generate hardware accelerators with up to better energy efficiency and requires less design effort.
Autors: Andrey Ayupov;Serif Yesil;Muhammet Mustafa Ozdal;Taemin Kim;Steven Burns;Ozcan Ozturk;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Feb 2018, volume: 37, issue:2, pages: 420 - 430
Publisher: IEEE
 
» A Templating System to Generate Provenance
Abstract:
prov-templateis a declarative approach that enables designers and programmers to design and generate provenance compatible with the prov standard of the World Wide Web Consortium. Designers specify the topology of the provenance to be generated by composing templates, which are provenance graphs containing variables, acting as placeholders for values. Programmers write programs that log values and package them up in sets of bindings, a data structure associating variables and values. An expansion algorithm generates instantiated provenance from templates and sets of bindings in any of the serialisation formats supported by prov. A quantitative evaluation shows that sets of bindings have a size that is typically 40 percent of that of expanded provenance templates and that the expansion algorithm is suitably tractable, operating in fractions of milliseconds for the type of templates surveyed in the article. Furthermore, the approach shows four significant software engineering benefits: separation of responsibilities, provenance maintenance, potential runtime checks and static analysis, and provenance consumption. The article gathers quantitative data and qualitative benefits descriptions from four different applications making use of prov-template. The system is implemented and released in the open-source library ProvToolbox for provenance processing.
Autors: Luc Moreau;Belfrit Victor Batlajery;Trung Dong Huynh;Danius Michaelides;Heather Packer;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Feb 2018, volume: 44, issue:2, pages: 103 - 121
Publisher: IEEE
 
» A Tensor-Based Holistic Edge Computing Optimization Framework for Internet of Things
Abstract:
Balancing the costs of different objectives in EC requires comprehensive and global analysis. This article investigates the holistic EC optimization problem for IoT. First, a triple-plane EC architecture for IoT is proposed including the edge device plane, edge server plane, and cloud plane, respectively, which is conducive to collaboratively accomplishing the EC applications. Then five tensor-based representation models are constructed to represent the complex relationships and resolve the heterogeneity of different devices. Afterward, we construct a generalized and holistic EC optimization model based on the constructed tensors including energy consumption, execution time, system reliability, and quality of experience. Finally, a customized optimization framework is proposed in which the optimization objectives can be arbitrarily combined according to practical applications. A case study is conducted to evaluate the performance of the proposed scheme; results demonstrate that it significantly outperforms the state-of-the-art cloud-assisted mobile computing scheme and holistic mobile cloud computing scheme.
Autors: Huazhong Liu;Laurence T. Yang;Man Lin;Dexiang Yin;Yimu Guo;
Appeared in: IEEE Network
Publication date: Feb 2018, volume: 32, issue:1, pages: 88 - 95
Publisher: IEEE
 
» A Theoretical Framework for Change Detection Based on a Compound Multiclass Statistical Model of the Difference Image
Abstract:
The change detection (CD) problem is very important in the remote sensing domain. The advent of a new generation of multispectral (MS) sensors has given rise to new challenges in the development of automatic CD techniques. In particular, typical approaches to CD are not able to well model and properly exploit the increased radiometric resolution characterizing new data as this results in a higher sensitivity to the number of natural classes that can be statistically modeled in the images. In this paper, we introduce a theoretical framework for the description of the statistical distribution of the difference image as a compound model where each class is determined by temporally correlated class transitions in the bitemporal images. The potential of the proposed framework is demonstrated on the very common problem of binary CD based on setting a threshold on the magnitude of the difference image. Here, under some simplifying assumptions, a multiclass distribution of the magnitude feature is derived and an unsupervised method based on the expectation–maximization algorithm and Bayes decision is proposed. Its effectiveness is demonstrated on a large variety of data sets from different MS sensors. In particular, experimental tests confirm that: 1) the fitting of the magnitude distribution significantly improves if compared with already existing models and 2) the overall CD error is close to the optimal value.
Autors: Massimo Zanetti;Lorenzo Bruzzone;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 1129 - 1143
Publisher: IEEE
 
» A Three-Dimensional Arrayed Microfluidic Blood–Brain Barrier Model With Integrated Electrical Sensor Array
Abstract:
Objective: The blood–brain barrier (BBB) poses a unique challenge to the development of therapeutics against neurological disorders due to its impermeabi-lity to most of the chemical compounds. Most in vitro BBB models have limitations in mimicking in vivo conditions and functions. Here, we show a co-culture microfluidic BBB-on-a-chip that provides interactions between neurovascular endothelial cells and neuronal cells across a porous polycarbonate membrane, which better mimics the in vivo conditions, as well as allows in vivo level shear stress to be applied. Methods: A 4 × 4 intersecting microchannel array forms 16 BBB sites on a chip, with a multielectrode array integrated to measure the transendothelial electrical resistance (TEER) from all 16 different sites, which allows label-free real-time analysis of the barrier function. Primary mouse endothelial cells and primary astrocytes were co-cultured in the chip while applying in vivo level shear stress. The chip allows the barrier function to be analyzed through TEER measurement, dextran permeability, as well as immunostaining. Results: Co-culture between astrocytes and endothelial cells, as well as in vivo level shear stress applied, led to the formation of tighter junctions and significantly lower barrier permeability. Moreover, drug testing with histamine showed increased permeability when using only endothelial cells compared to almost no change when using co-culture. Conclusion: Results show that the developed BBB chip more closely mimics the in vivo BBB environment. Significance: The developed multisite BBB chip is expected to be used for screening drug by more accurately predicting their permeability through BBB as well as their toxicity.
Autors: Sehoon Jeong;Sunja Kim;John Buonocore;Jaewon Park;C. Jane Welsh;Jianrong Li;Arum Han;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Feb 2018, volume: 65, issue:2, pages: 431 - 439
Publisher: IEEE
 
» A Three-Dimensional Magnetic Tweezer System for Intraembryonic Navigation and Measurement
Abstract:
Magnetic micromanipulation has the advantage of untethered control, high precision, and biocompatibility and has recently undergone great advances. The magnetic micromanipulation task to tackle in this paper is to three dimensionally navigate a 5-m magnetic bead inside a mouse embryo and accurately apply forces to intraembryonic structures to perform mechanical measurements at multiple locations. Existing technologies are not able to achieve these navigation and measurement goals because of poor magnetic force scaling and/or lacking the capability of applying an accurately controlled force. This paper reports a three-dimensional magnetic tweezer system that enables, for the first time, intraembryonic magnetic navigation and force application. A single magnetic bead was introduced into a mouse embryo via robotic microinjection. The magnetic tweezer system accurately controlled the position of the magnetic bead via visually servoed magnetic control. By moving the magnetic bead with known forces inside the embryo, cytoplasm viscosity was measured, which is eight times the viscosity of water. For performing mechanical measurements on the cellular structures inside the mouse embryo, the system should be capable of applying forces up to 120 pN with a resolution of 4 pN. The results revealed that the middle region is significantly more deformable than the side regions of the inner cell mass.
Autors: Xian Wang;Mengxi Luo;Han Wu;Zhuoran Zhang;Jun Liu;Zhensong Xu;Wesley Johnson;Yu Sun;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 240 - 247
Publisher: IEEE
 
» A Three-Dimensional-FEM Model With Experimentally Determined Material Parameters of an FBG Sensor Element in a Panda-Type Fiber
Abstract:
A 20-mm-long 3D-FEM model of a Panda fiber was developed to improve the understanding of multiparameter sensing in attached or embedded polarization maintaining (PM) fibers. Previously unknown but for FEM modeling critical material parameters of the fiber's stress applying parts (SAP) were determined by a combination of measurements and simulations. The methodology gave evidence of a doping concentration of about 24 mole-% B2O3 in the SAPs for the specific type of PM fiber used. The model was evaluated for axial strains up to 1600 μstrain, axial stress up to 170 MPa, and in a temperature range from –40 to 160 °C. The simulated changes in the Bragg wavelengths of the slow and the fast axes and the change of their separation due to applied axial strain, stress, and temperature variations were in good agreement with measured data. A reliable 3D-FEM model of an FBG in a Panda fiber is now available that can be integrated into larger FEM models of embedded or surface-glued sensors fibers of type Panda. The model can be used to predict the influences of any arbitrary mechanical loads on an FBG in a Panda-type fiber at different temperatures.
Autors: Barbara Hopf;Bennet Fischer;Markus Lindner;Alexander Wilhelm Koch;Johannes Roths;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2018, volume: 36, issue:4, pages: 1076 - 1083
Publisher: IEEE
 
» A Tightly Integrated Multilayer Battery Antenna for RFID Epidermal Applications
Abstract:
For the acceptance of biointegrated devices in daily life, radio systems must be developed, which are minimally invasive to the skin, and they must have ultralow-profile local power sources to support data-logging functionality without compromising shape conformability. This contribution proposes a tightly integrated multilayer battery-antenna system ( mm2), that is, ultrathin (just ), flexible, and lighter than 1 , making it suitable for epidermal applications. The negative electrode (anode) current collector of the battery is a radio frequency identification tag antenna coated by a conductive polymer (Pedot:PSS) working as anode material. Since the battery is a dynamic device, subjected to discharging, the antenna design must include the variable dielectric properties of the conductive polymer which are here first characterized in the UHF band for real charge/discharge battery conditions. The communication performance of the prototype composite device is hence evaluated through the measurement of the realized gain of the tag antenna (−19.6 dBi at 870 MHz) when it is placed directly onto a volunteer’s forearm. The read range of 1.3–3 m is suitable for occasional data download from the epidermal data logger when the user comes close to a reader-equipped gate.
Autors: Maria Cristina Caccami;Matteo P. Hogan;Maria Alfredsson;Gaetano Marrocco;John C. Batchelor;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 609 - 617
Publisher: IEEE
 
» A Transformerless High-Voltage DC–DC Converter for DC Grid Interconnection
Abstract:
This paper presents a transformerless high-voltage dc–dc converter based on cascaded sub-modules. It is intended for interconnecting high-voltage or medium-voltage dc grids. The proposed dc–dc converter consists of two phase legs, each of which consists of an upper arm and a lower arm with their middle nodes crossly connected through a branch of active sub-modules. By properly controlling the output voltage of the cross-connected branch, a trapezoidal ac current is induced to interact with the ac voltage components in the upper and lower arm for rebalancing the power amongst converter arms. The features of modular design, single-stage power conversion, and transformerless structure make the proposed dc–dc converter gain the outstanding merits of wide voltage ratio range, high system efficiency, and light converter weight. A control scheme is also elaborated for guaranteeing the normal operation of the proposed dc–dc converter. A 100-kV 100-MW simulation model performed in MATLAB/Simulink verifies the feasibility of the proposed dc–dc converter. Experimental results obtained from a 100-V 1-kW laboratory setup also confirm the validation of the proposal.
Autors: Sixing Du;Bin Wu;Navid R. Zargari;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 282 - 290
Publisher: IEEE
 
» A Two-Phase Fuzzy Clustering Algorithm Based on Neurodynamic Optimization With Its Application for PolSAR Image Segmentation
Abstract:
This paper presents a two-phase fuzzy clustering algorithm based on neurodynamic optimization with its application for polarimetric synthetic aperture radar (PolSAR) remote sensing image segmentation. The two-phase clustering algorithm starts with the linear-assignment initialization phase with the least similar cluster representatives to remedy the inconsistency of clustering results from random initialization and is, then, followed with multiple-kernel fuzzy C-means clustering. By incorporating multiple kernels in the clustering framework, various features are incorporated cohesively. A winner-takes-all neural network is employed to acquire the highest kernel weights and associated cluster centers and membership matrices, which enables better characterization and adaptability in each individual cluster. Simulation results for UCI benchmark datasets and PolSAR remote sensing image segmentation are reported to substantiate the effectiveness and the superiority of the proposed clustering algorithm.
Autors: Jianchao Fan;Jun Wang;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Feb 2018, volume: 26, issue:1, pages: 72 - 83
Publisher: IEEE
 
» A Two-Port Nonlinear Dynamic Behavioral Model of RF PAs Subject to Wideband Load Modulation
Abstract:
This work presents a full two-port, i.e., double input-double output, behavioral modeling approach suitable for radio frequency power amplifiers (PAs) in the presence of dynamic load modulation (DLM). The formulation of the model, based on a first-order approximation of a modified Volterra series, accounts for the nonlinear distortion determined by large-signal operation under mismatched conditions, and also for the memory effects stimulated by a modulated PA input signal, or by the dynamic variations of the PA load. By following an exhaustive procedure defined in the frequency domain, the model of a general purpose commercial PA is extracted over 160 MHz of modulation bandwidth (BW) with nonlinear vector network analyzer measurements. Validation results under 20-MHz BW multisine excitation and injected 80-MHz BW multisine load modulation show improved prediction capabilities with respect to quasi-static or single-input descriptions, allowing for reliable system-level simulations in the presence of DLM.
Autors: Gian Piero Gibiino;Konstanty Łukasik;Paweł Barmuta;Alberto Santarelli;Dominique M. M.-P. Schreurs;Fabio Filicori;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Feb 2018, volume: 66, issue:2, pages: 831 - 844
Publisher: IEEE
 
» A Two-Stage Quasi-Resonant Dual-Buck LED Driver With Digital Control Method
Abstract:
A two-stage quasi-resonant LED driver with a digital control method is proposed in this paper. The first stage of this converter is a boost circuit with a power factor correction function, and the second stage is a dual-buck circuit that works in a quasi-resonant zero voltage switching state. Because of the soft-switching characteristics of the converter, switching losses are reduced and efficiency is significantly improved. A digital control method is adopted to detect the peak value of inductor current and enhance system reliability. Moreover, because LEDs are always driven by a current source, a current loop is designed to maintain constant output current. IRS2104 is chosen as the drive chip and the microcontroller is AT90PWM216, which can improve the quality of the drive signals. The output of the converter is a square wave that drives two branches of antiparallel LEDs. A 60-W prototype was designed to demonstrate the theoretical analysis. The obtained power factor was as high as 0.987 and the efficiency reached 92.3%.
Autors: Yijie Wang;Shanshan Gao;Shu Zhang;Dianguo Xu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2018, volume: 54, issue:1, pages: 787 - 795
Publisher: IEEE
 
» A Unified Optimal Control Approach for Maximum Endurance and Maximum Range
Abstract:
This paper proposes a unified optimal control framework that can be used to formulate and solve aircraft performance problems, such as maximum endurance and maximum range, for both propeller-driven airplanes and jet-propelled aircraft. It is proved in this paper that such problems have a common mathematical formulation and, under strict convexity assumptions, they have a unique feedback solution for the speed as a function of weight. The feedback solution yields an analytic expression for the optimal speed. For maximum endurance, the solution corresponds to the minimization of the rate of fuel consumption per unit time. For maximum range, the rate of fuel consumption per unit distance is minimized. Moreover, the optimal solution for maximum range will be interpreted geometrically using the concept of convex conjugate function and Legendre transformation. Although the optimal control framework is illustrated for maximum range and maximum endurance, it is a general approach that can be used for other aircraft performance problems.
Autors: Luis Rodrigues;
Appeared in: IEEE Transactions on Aerospace and Electronic Systems
Publication date: Feb 2018, volume: 54, issue:1, pages: 385 - 391
Publisher: IEEE
 
» A Unified Scalable Quasi-Ballistic Transport Model of GFET for Circuit Simulations
Abstract:
A unified quasi-ballistic transport model is developed for single- and double-gate graphene field-effect transistors (GFETs) using the McKelvey flux theory approach. The proposed model is compact, scalable, and compatible for the simulation of – characteristics of GFET for all regions of device operation. The drain current equation () incorporates the formulation of quasi-thermal velocity, quasi-ballistic mobility of charge carrier (describe the carrier transport of 2-D material like graphene), and source/drain backscattering coefficient. This model is also capable to describe the mobility of graphene material in degenerate and nondegenerate states. The GFET with different channel lengths, widths, and oxide thicknesses is simulated using this model for single- and double-gate devices. The proposed model synchronized with experimental results and explains the peculiar transport characteristics of GFET with normalized root-mean-square error less than 9%.
Autors: Abhishek Kumar Upadhyay;Ajay Kumar Kushwaha;Santosh Kumar Vishvakarma;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 739 - 746
Publisher: IEEE
 
» A Uniplanar Left-Handed Metamaterial for Terrestrial Microwave Links
Abstract:
This letter reveals a mm2 metamaterial unit cell using coupled rectangular split-ring resonator (SRR), fabricated on only one side of the epoxy resin fiber substrate material. The proposed design consists of two separate SRRs outside and three split array rectangles with a small rectangle inside. It gives a wide magnetic repose throughout the C-band (4–8 GHz) microwave frequency spectrum. In the lower frequency band, the inclusion shows a negative epsilon, and in the upper frequency band, it shows double-negative characteristics (bandwidths of 0.72, 0.52, 0.2, and 0.71 GHz) with low losses in the C-band frequency range. The perceptible novelty of the proposed metastructure is achieved negative permeability throughout the whole C-band maintaining an effective medium ratio of 4.5.
Autors: Farhad Bin Ashraf;Touhidul Alam;Mohammad Tariqul Islam;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Feb 2018, volume: 28, issue:2, pages: 108 - 110
Publisher: IEEE
 
» A Universal Destriping Framework Combining 1-D and 2-D Variational Optimization Methods
Abstract:
Striping effects are a common phenomenon in remote-sensing imaging systems, and they can exhibit considerable differences between different sensors. Such artifacts can greatly degrade the quality of the measured data and further limit the subsequent applications in higher level remote-sensing products. Although a lot of destriping methods have been proposed to date, a few of them are robust to different types of stripes. In this paper, we conduct a thorough feature analysis of stripe noise from a novel perspective. With regard to the problem of striping diversity and complexity, we propose a universal destriping framework. In the proposed destriping procedure, a 1-D variational method is first designed and utilized to estimate the statistical feature-based guidance. The guidance information is then incorporated into 2-D optimization to control the image estimation for a reliable and clean output. The iteratively reweighted least-squares method and alternating direction method of multipliers are exploited in the proposed approach to solve the minimization problems. Experiments under various cases of simulated and real stripes confirm the effectiveness and robustness of the proposed model in terms of the qualitative and quantitative comparisons with other approaches.
Autors: Xinxin Liu;Huanfeng Shen;Qiangqiang Yuan;Xiliang Lu;Chunping Zhou;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2018, volume: 56, issue:2, pages: 808 - 822
Publisher: IEEE
 
» A Variable-Clock-Cycle-Path VLSI Design of Binary Arithmetic Decoder for H.265/HEVC
Abstract:
The next-generation 8K ultra-high-definition video format involves an extremely high bit rate, which imposes a high throughput requirement on the entropy decoder component of a video decoder. Context adaptive binary arithmetic coding (CABAC) is the entropy coding tool in the latest video coding standards including H.265/High Efficiency Video Coding and H.264/Advanced Video Coding. Due to critical data dependencies at the algorithm level, a CABAC decoder is difficult to be accelerated by simply leveraging parallelism and pipelining. This letter presents a new very-large-scale integration arithmetic decoder, which is the most critical bottleneck in CABAC decoding. Our design features a variable-clock-cycle-path architecture that exploits the differences in critical path delay and in probability of occurrence between various types of binary symbols (bins). The proposed design also incorporates a novel data-forwarding technique (rLPS forwarding) and a fast path-selection technique (coarse bin type decision), and is enhanced with the capability of processing additional bypass bins. As a result, its maximum throughput achieves 1010 Mbins/s in 90-nm CMOS, when decoding 0.96 bin per clock cycle at a maximum clock rate of 1053 MHz, which outperforms previous works by 19.1%.
Autors: Jinjia Zhou;Dajiang Zhou;Shuping Zhang;Shinji Kimura;Satoshi Goto;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Feb 2018, volume: 28, issue:2, pages: 556 - 560
Publisher: IEEE
 
» A Wearable Multi-Site System for NMES-Based Hand Function Restoration
Abstract:
Reaching and grasping impairments significantly affect the quality of life for people who have experienced a stroke or spinal cord injury. The long-term well-being of patients varies greatly according to the restorable residual capabilities. Electrical stimulation could be a promising solution to restore motor functions in these conditions, but its use is not clinically widespread. Here, we introduce the HandNMES, an electrode array (EA) for neuromuscular electrical stimulation (NMES) aimed at grasp training and assistance. The device was designed to deliver electrical stimulation to extrinsic and intrinsic hand muscles. Six independent EAs, positioned on the user forearm and hand, deliver NMES pulses originating from an external stimulator equipped with demultiplexers for interfacing with a large number of electrodes. The garment was designed to be adaptable to user needs and anthropometric characteristics; size, shape, and contact materials can be customized, and stimulation characteristics such as intensity of stimulation and virtual electrode location, and size can be adjusted. We performed extensive tests with nine healthy subjects showing the efficacy of the HandNMES in terms of stimulation performance and personalization. Because encouraging results were achieved, in the coming months, the HandNMES device will be tested in pilot clinical trials.
Autors: Andrea Crema;Nebojša Malešević;Ivan Furfaro;Flavio Raschellà;Alessandra Pedrocchi;Silvestro Micera;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Feb 2018, volume: 26, issue:2, pages: 428 - 440
Publisher: IEEE
 
» A Wearable Piezoelectric Energy Harvester Rectified by a Dual-Gate Thin-Film Transistor
Abstract:
This paper addresses a wearable piezoelectric energy harvester that combines a PVDF piezoelectric charge generator with an a-Si:H dual-gate thin-film transistor as a rectifier. An analytical model and equivalent circuit elaborate their working principle and device physics. A preliminary experimental study proves the device concept and demonstrates that such a harvester is capable of generating microwatt-range power with a simple 90° finger bending action. Coupled with low-cost and large-area fabrication processes, a pixelated energy-harvesting array can be potentially achievable, making it a promising alternative to energy sources for wearable electronics.
Autors: Emad Iranmanesh;Ahmed Rasheed;Weiwei Li;Kai Wang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2018, volume: 65, issue:2, pages: 542 - 546
Publisher: IEEE
 
» A Wide-Range Model for Metal-Oxide Surge Arrester
Abstract:
This paper presents an electric model of a metal-oxide surge arrester (MOSA). The proposed electric model accurately represents the MOSA in a wide range of frequencies and amplitudes. The model was developed and validated based on MOSA electrical behavior in each one of the three operating regions of the zinc-oxide (ZnO) surge arresters, and in a database composed of voltage and current waveforms measured from tests performed in 12 ZnO varistors having different physical dimensions and electrical characteristics—from five different manufacturers. These varistors were subjected to different voltage levels in the low current region, and multilevel amplitude of switching current impulses (30/60 s), lightning current impulses (8/20 s), high current impulses (4/10 s), and fast-front current impulses (1.5/26 s and 3/6 s) encompass the three regions of operation and a wide range of frequencies and amplitudes. The results provided by the MOSA wide-range (MWR) model were compared with those obtained in the laboratory. The MWR model has shown good agreement in terms of waveform, peak value, and absorbed energy for the evaluated cases.
Autors: Valdemir S. Brito;George R. S. Lira;Edson G. Costa;Marcelo J. A. Maia;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Feb 2018, volume: 33, issue:1, pages: 102 - 109
Publisher: IEEE
 
» A Wideband Reconfigurable Antenna With 360° Beam Steering for 802.11ac WLAN Applications
Abstract:
A novel 360° beam steering patch antenna with parasitic elements is presented in this paper. The designed antenna consists of a radiating patch and six parasitic elements, each of which is connected through a group of shorting vias controlled by p-i-n diode switches. By switching on the desired groups of the shorting vias, the electric field distribution inside substrate cavity appears at the desired beam direction. Rotationally switching on the groups of the shorting vias, the performance of 360° beam scanning is realized. To further understand operating mechanism, the antenna is modeled with equivalent circuit in terms of the on and off status of a sector of the antenna, which can be used as a design guide for shorting-vias-controlled reconfigurable microstrip patch antennas. The fabricated antenna achieves a bandwidth of 14.5%, a peak gain of 10 dBi, and the efficiency of 80.5%. The achieved beamwidths are 42° and 97° in azimuth and elevation planes, respectively. With an ability of being steered around zenith axis at six directions, the scanned beam range covers the entire 360°. The physical dimension is only for the size and for the profile. This antenna operates from 5.1 to 5.9 GHz and has significant meaning in the IEEE 802.11ac wireless local area network applications due to its capabilities of generating 360° steered beams.
Autors: Yang Yang;Xi Zhu;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2018, volume: 66, issue:2, pages: 600 - 608
Publisher: IEEE
 
» A ZF-Based Precoding Scheme With Phase Noise Suppression for Massive MIMO Downlink Systems
Abstract:
In wireless communications, massive multiple-input multiple-output (MIMO) systems in which the base station (BS) is equipped with a large number of antennas can provide significant spectral and energy efficiency by means of simple signal processing. Therefore, massive MIMO is an attractive technology for next-generation wireless communication systems and for green communications. However, phase noise (PN) introduced by the impairment of oscillators can cause a severe performance loss in wireless communication systems. Solving the PN problem for massive MIMO systems in both the downlink and uplink is challenging as it is a multivariate joint PN estimation and data detection problem. The optimal solution is difficult to derive and may lead to high complexity. In this paper, we propose a zero-forcing (ZF) based precoding scheme with PN suppression to solve the PN problem for massive MIMO downlink systems. By using the ideal PN free output signal-to-noise ratio (SNR) of the ZF precoding as a performance upper bound, analytical and numerical results show that when the required SNR is satisfied, the output SNR of the proposed scheme can approach the upper bound, except for very large PN variances. Moreover, the complexity of the proposed scheme is low on both the BS and the user sides, and the BS does not need any feedback information from the users.
Autors: Yi-Fan Wang;Ju-Hong Lee;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1158 - 1173
Publisher: IEEE
 
» Absorption Enhancement for Black Phosphorus Active Layer Based on Plasmonic Nanocavity
Abstract:
In this letter, we propose a strategy to enhance absorption in the black phosphorus absorber based on a nanocavity structure. By introducing a porous silver layer, an enhanced broadband light absorption can be obtained in the spectral range of 520–820 nm. The optical characteristics of the black phosphorus absorptive layer are thoroughly analyzed by absorption spectra, electric intensity distribution, and power flow distribution. Numerical and analytical analysis revealed that the optical absorption of the black phosphorus layer with a porous silver layer can be enhanced by 50% and 396% at the resonant wavelength of 690 nm for p-polarized and s-polarized incidences, respectively, when compared to that without a silver layer. Furthermore, the short-circuit current density () was calculated for the proposed architecture. The peak value of was more than 18 mA/cm2. It is demonstrated that this super absorption structure could find important applications on plasmonic-assisted photovoltaic devices or other opto-electronic devices, which will promote the development of ultrathin on-chip energy harvesting and new thin-film active devices.
Autors: Cizhe Fang;Yan Liu;Genquan Han;Yao Shao;Yan Huang;Jincheng Zhang;Yue Hao;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 10
Publisher: IEEE
 
» AC-POCA: Anticoordination Game Based Partially Overlapping Channels Assignment in Combined UAV and D2D-Based Networks
Abstract:
Device-to-device (D2D)-enabled wireless networks are becoming increasingly popular. However, in remote, rural, and disaster affected areas, it is difficult to construct such wireless networks due to the unavailability or inadequacy of cellular infrastructures. Unmanned aerial vehicles (UAVs) can be a good candidate to promptly construct the D2D-enabled wireless network. However, the assignment of the radio channels of the nodes (i.e., UAVs and user terminals) is challenging due to the availability of only a limited number of orthogonal channels and the interference issue resulted from using arbitrary channels. Furthermore, the dynamic topology and high mobility of nodes in such a combined UAV and D2D-based network make conventional channel assignment (CA) algorithm no longer suitable. In this paper, we formally address this problem, and demonstrate how partially overlapping channels (POCs) and game theory can be exploited to alleviate the problem. In this vein, we propose a distributed anticoordination game based POC assignment algorithm referred to as AC-POCA. In our proposed AC-POCA, the nodes use only local information to play the game, and reach a steady state, uniqueness of which is verified through analysis. Also, the upper bound of AC-POCA (i.e., price of anarchy) is analytically evaluated, which is corroborated by simulation results. In addition, simulation results demonstrate the effectiveness of AC-POCA in terms of good throughput and low signaling overhead in a dynamic environment.
Autors: Fengxiao Tang;Zubair Md. Fadlullah;Nei Kato;Fumie Ono;Ryu Miura;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1672 - 1683
Publisher: IEEE
 
» Academic FabLabs for industry 4.0: Experience at University of Naples Federico II
Abstract:
From FabLabs new and important business opportunities can emerge in the world of Adaptive Manufacturing and the Internet of Things (IoT), by leveraging the services provided by large information technology (IT) companies, such as cloud computing. FabLabs aim to foster the creation of small start-ups, able to survive in a global market with rising fierce competition. Therefore, governance action is needed to facilitate this migration to the market through regulatory measures (economic support for youth start-ups, business accelerators, co-working spaces, incubators, and so on). What is most important, and scarcely realized, is the specific training of young IT engineers intended to grow into makers. The experience gained at the University of Naples Federico II in Naples, Italy in this area is described in this paper. A new model of teaching for students pursuing the Master of Science Degrees in Electrical and Information Engineering was proposed, aimed at reproducing the aspects, the problems, and the interactions unique to small IT business, and later giving rise to a FabLAB.
Autors: Leopoldo Angrisani;Pasquale Arpaia;Francesco Bonavolonta;Rosario Schiano Lo Moriello;
Appeared in: IEEE Instrumentation & Measurement Magazine
Publication date: Feb 2018, volume: 21, issue:1, pages: 6 - 13
Publisher: IEEE
 
» Accelerated Parameter Mapping of Multiple-Echo Gradient-Echo Data Using Model-Based Iterative Reconstruction
Abstract:
A new reconstruction method, coined MIRAGE, is presented for accurate, fast, and robust parameter mapping of multiple-echo gradient-echo (MEGE) imaging, the basis sequence of novel quantitative magnetic resonance imaging techniques such as water content and susceptibility mapping. Assuming that the temporal signal can be modeled as a sum of damped complex exponentials, MIRAGE performs model-based reconstruction of undersampled data by minimizing the rank of local Hankel matrices. It further incorporates multi-channel information and spatial prior knowledge. Finally, the parameter maps are estimated using nonlinear regression. Simulations and retrospective undersampling of phantom and in vivo data affirm robustness, e.g., to strong inhomogeneity of the static magnetic field and partial volume effects. MIRAGE is compared with a state-of-the-art compressed sensing method, -ESPIRiT. Parameter maps estimated from reconstructed data using MIRAGE are shown to be accurate, with the mean absolute error reduced by up to 50% for in vivo results. The proposed method has the potential to improve the diagnostic utility of quantitative imaging techniques that rely on MEGE data.
Autors: Markus Zimmermann;Zaheer Abbas;Krzysztof Dzieciol;N. Jon Shah;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Feb 2018, volume: 37, issue:2, pages: 626 - 637
Publisher: IEEE
 
» Accumulated Angle Factor-Based Beamforming to Improve the Visualization of Spinal Structures in Ultrasound Images
Abstract:
In recent years, ultrasound has been increasingly used to guide needle insertion procedures for spinal anesthesia. The primary anatomical targets are facet joints and epidural spaces. For these procedures, accurate visualization of the spine anatomy is of critical importance. Challenges arising from the interactions between the ultrasound beam and spinal structures including tilt caused by specular reflections, off-axis interference, and reverberations often result in weakened and blurred vertebra surfaces. Previously, adaptive beamforming methods have been proposed to improve the resolution and contrast. However, most of these methods are not specialized for improving the contrast of specular targets like bones. In this paper, we propose an accumulated angle factor (AAF)-based beamforming method customized for bone surface enhancement. This approach applies a Hilbert transform on delay compensated channel data across the receive aperture. The accumulated phase change across the receive aperture is then calculated and utilized as the weight in the beamforming output. We compared our method with classical delay and sum (DAS) beamforming method and adaptive beamforming methods such as Wiener, phase coherence factor (PCF), CF, and generalized CF (GCF) beamforming. In 12 volunteer data sets, the mean contrast ratio between the vertebrae surface and the surrounding tissue for DAS, Wiener, PCF, CF, GCF, and the proposed AAF methods are 0.49, 0.64, 0.82, 0.77, 0.76, and 0.91, respectively. The contrast is significantly improved in the proposed method.
Autors: Bo Zhuang;Robert Rohling;Purang Abolmaesumi;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Feb 2018, volume: 65, issue:2, pages: 210 - 222
Publisher: IEEE
 
» Accuracy of Angle Rate Measurements Using a Distributed Radar With a Correlation Receiver
Abstract:
Direct measurements of the angle rate of moving objects using a distributed radar have recently been demonstrated in theory and practice. In this letter, the theoretical accuracy of angle rate measurements using a simple correlation receiver is derived and compared to the theoretical accuracy of a more general but less intuitive root-multiplier receiver described in previous work. In particular, the correlation receiver bound on angle rate accuracy is shown to be dependent on the radiation intensity of the electric field rather than the field itself, as is the case for the root-multiplier receiver. The result is that the correlation receiver does not as closely represent the optimal form to achieve the theoretical bound on measurement accuracy. However, despite this, it is shown that there are clear operational regions where the correlation receiver nonetheless outperforms the more general root-multiplier receiver.
Autors: Matthew D. Sharp;Jeffrey A. Nanzer;
Appeared in: IEEE Antennas and Wireless Propagation Letters
Publication date: Feb 2018, volume: 17, issue:2, pages: 209 - 212
Publisher: IEEE
 
» Accurate Analysis of Crosstalk Between LP$_{11}$ Quasi-Degenerate Modes Due to Offset Connection Using True Eigenmodes
Abstract:
Linearly polarized (LP) modes in few-mode fibers are not true eigenmodes but approximated modes constituting of linear combinations of true eigenmodes. Therefore, the vector field profile in a few-mode fiber must be expressed in terms of the true eigenmodes with complex amplitudes involving a phase difference corresponding to the propagation distance. Owing to this property of LP mode propagation, the propagation characteristics of few-mode fibers cannot be accurately analyzed using conventional LP modes. In this study, the crosstalk between LP quasi-degenerate modes due to offset connection is accurately analyzed using matrix formalism expressing the linear combination of true eigenmodes. The difference in the analytical results between the LP modes and the eigenmodes revealed that the propagation of few-mode fibers should be analyzed using true eigenmodes.
Autors: Seiya Miura;Tatsuhiko Watanabe;Yasuo Kokubun;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 11
Publisher: IEEE
 
» Accurate Modeling of GaN HEMT RF Behavior Using an Effective Trapping Potential
Abstract:
This paper investigates the back-gating effects due to traps, and presents a new nonlinear trap modeling approach suitable for gallium nitride (GaN) high electron mobility transistors (HEMTs). It is shown that the traps have nonidentical influence on the channel compared with the gate. The potential due to trapped electrons in the buffer and the gate–source voltage need to be differentiated to model their respective influence on conductivity of the 2-D electron gas. Hence, the back-gating potential due to traps cannot be included in the transistor model by directly offsetting the gate–source voltage. A new modulation factor is therefore introduced to create an effective back-gating potential, and thereby improve the modeling of trapping effects. The proposed nonlinear trap model is shown to accurately predict the trapping behavior for a large voltage operating region. A detailed procedure is presented to derive the model parameters from basic device measurements. The model is experimentally validated and shown to accurately predict dc-, pulsed-IV, and large-signal waveform performance for a commercial GaN HEMT.
Autors: Ankur Prasad;Mattias Thorsell;Herbert Zirath;Christian Fager;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Feb 2018, volume: 66, issue:2, pages: 845 - 857
Publisher: IEEE
 
» Achieving Full-Duplex Communication: Magnetless Parametric Circulators for Full-Duplex Communication Systems
Abstract:
In a crowded electromagnetic spectrum with ever-increasing demand for higher data rates to enable multimedia-rich applications and services, the efficient use of wireless resources becomes crucial. For this reason, full-duplex communication [1]-[4], which increases the capacity of transmission channels by operating the uplink and downlink simultaneously on the same frequency channel (see Figure 1), is returning to the spotlight after decades of being presumed impractical. This long-held assumption resulted mainly from the need for large isolation (IX) between the transmit (Tx) and receive (Rx) nodes [also known as self-interference cancellation (SIC)], which typically needs to be greater than 100 dB, a challenging task that requires several innovations at the network and physical layer levels.
Autors: Ahmed Kord;Dimitrios L. Sounas;Andrea Alù;
Appeared in: IEEE Microwave Magazine
Publication date: Feb 2018, volume: 19, issue:1, pages: 84 - 90
Publisher: IEEE
 
» Achieving High Scalability Through Hybrid Switching in Software-Defined Networking
Abstract:
Traditional networks rely on aggregate routing and decentralized control to achieve scalability. On the contrary, software-defined networks achieve near optimal network performance and policy-based management through per-flow routing and centralized control, which, however, face scalability challenge due to: 1) limited ternary content addressable memory and on-die memory for storing the forwarding table and 2) per-flow communication/computation overhead at the controller. This paper presents a novel hybrid switching (HS) design, which integrates traditional switching and software-defined networking (SDN) switching for the purpose of achieving both scalability and optimal performance. We show that the integration also leads to unexpected benefits of making both types of switching more efficient under the hybrid design. We also design the general optimization framework via HS and propose an approximation algorithm for load-balancing optimization as a case study. Testing and numerical evaluation demonstrate the superior performance of HS when comparing with the state-of-the-art SDN design.
Autors: Hongli Xu;He Huang;Shigang Chen;Gongming Zhao;Liusheng Huang;
Appeared in: IEEE/ACM Transactions on Networking
Publication date: Feb 2018, volume: 26, issue:1, pages: 618 - 632
Publisher: IEEE
 
» ACID: Association Correction for Imbalanced Data in GWAS
Abstract:
Genome-wide association study (GWAS) has been widely witnessed as a powerful tool for revealing suspicious loci from various diseases. However, real world GWAS tasks always suffer from the data imbalance problem of sufficient control samples and limited case samples. This imbalance issue can cause serious biases to the result and thus leads to losses of significance for true causal markers. To tackle this problem, we proposed a computational framework to perform association correction for imbalanced data (ACID) that could potentially improve the performance of GWAS under the imbalance condition. ACID is inspired by the imbalance learning theory but is particularly modified to address the task of association discovery from sequential genomic data. Simulation studies demonstrate ACID can dramatically improve the power of traditional GWAS method on the dataset with severe imbalances. We further applied ACID to two imbalanced datasets (gastric cancer and bladder cancer) to conduct genome wide association analysis. Experimental results indicate that our method has better abilities in identifying suspicious loci than the regression approach and shows consistencies with existing discoveries.
Autors: Feng Bao;Yue Deng;Qionghai Dai;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Feb 2018, volume: 15, issue:1, pages: 316 - 322
Publisher: IEEE
 
» Acoustic Tag Identification Based on Noncoherent FSK Detection With Portable Devices
Abstract:
This paper presents a tag identification system based on the detection of high-frequency acoustic signals by means of a portable device. A binary frequency shift keying-modulated code is used to tag the different locations. This code is preceded by a synchronizing chirp waveform that allows noncoherent detection even under strong Doppler frequency shifts. The proposed system is first characterized in terms of robustness against noise, coverage, Doppler tolerance, and intertag interference, making use of a modular simulator. This simulator is based on three basic stages that account for the frequency response of the emitter–receiver pair, the attenuation of acoustic signals in air, and the noncoherent demodulation. This system is then implemented in an Android-based platform and tested in a real scenario. The results of this experimental analysis show good agreement with the previous characterization, and they also confirm the feasibility of the proposed system to develop location-aware applications.
Autors: Fernando J. Álvarez;Teodoro Aguilera;José A. Paredes;José A. Moreno;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Feb 2018, volume: 67, issue:2, pages: 270 - 278
Publisher: IEEE
 
» Across Substrate Lateral Dimensional Repeatability Using a Highly-Anisotropic Deep Etch Process on Fused Silica Material Layers
Abstract:
This letter reports the research performed on the measurement of the repeatability of the resultant lateral dimensions across fused silica substrates that were etched using an inductively-coupled plasma reactive-ion etch process. We have developed and previously reported a highly-anisotropic plasma etch process with the demonstrated etch depths of over 100 microns deep into fused silica substrates and aspect ratios greater than 10 to 1. The across substrate repeatability of the lateral dimensions of the etched features is an extremely important parameter for any plasma etch process. The measured etched feature lateral dimensional repeatability for an average etch depth of 100 microns was found to be approximately 2.41% across each wafer over a total of 120 measurements taken. The capability to etch highly-anisotropic deep features with repeatable dimensional control into fused silica has important implications for a number of important MEMS applications. [2017-0088]
Autors: Michael Pedersen;Michael Huff;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Feb 2018, volume: 27, issue:1, pages: 31 - 33
Publisher: IEEE
 
» Actionable Analytics for Software Engineering
Abstract:
Although intensive research on software analytics has been going on for nearly a decade, a repeated complaint in software analytics is that industrial practitioners find it hard to apply the results generated from data science. This theme issue aims to reflect on actionable analytics for software engineering and to document a catalog of success stories in which analytics has been proven actionable and useful, in some significant way, in an organization. This issue features five articles covering promising analytical methods for improving change triage, strategic maintenance, and team robustness, as well as the success stories of applying analytical tools during an organizational transformation.
Autors: Ye Yang;Davide Falessi;Tim Menzies;Jairus Hihn;
Appeared in: IEEE Software
Publication date: Feb 2018, volume: 35, issue:1, pages: 51 - 53
Publisher: IEEE
 
» Actionable Analytics for Strategic Maintenance of Critical Software: An Industry Experience Report
Abstract:
NASA has been successfully sustaining the continuous operation of its critical navigation software systems for over 12 years. To accomplish this, NASA scientists must continuously monitor their process, report on current system quality, forecast maintenance effort, and sustain required staffing levels. This report presents some examples of the use of a robust software metrics and analytics program that enables actionable strategic maintenance management of a critical system (Monte) in a timely, economical, and risk-controlled fashion. This article is part of a special issue on Actionable Analytics for Software Engineering.
Autors: Dan Port;Bill Taber;
Appeared in: IEEE Software
Publication date: Feb 2018, volume: 35, issue:1, pages: 58 - 63
Publisher: IEEE
 
» Active Control of Dye Release for Neuronal Tracing Using PEDOT-PSS Coated Electrodes
Abstract:
Penetrating neural probes comprising arrays of microelectrodes are commonly used to monitor local field potentials and multi-unit activity in animal brain over time frames of weeks. To correlate these recorded signals to specific tissue areas, histological analysis is performed after the experimental endpoint. Even if the lesion of the penetrating probe shaft can be observed, a precise reconstruction of the exact electrode positions is still challenging. To overcome these experimental difficulties, we developed a new concept, whereupon recording electrodes are coated with a poly (3, 4-ethylenedioxythiophene/ polystyrenesulfonate) (PEDOT/PSS)-based film. The conducting polymer acts as dye reservoir over several weeks and afterwards provides controlled delivery of neurotracers. This paper presents a recording electrode based on a PEDOT/PSS bilayer optimized for dye delivery and with reduced impedance. Controlled exchange of neurotracer dye is successfully demonstrated in vitro using spectrofluorometry and in neuroblastoma cell cultures. A second PEDOT/PSS capping layer on top of the dye reservoir lowers the passive leakage of dye by a factor of 6.4 and prevents a direct contact of the dye filled layer with the cells. Stability tests over four weeks demonstrate the electrochemical stability of the PEDOT coating, as well as retained functionality of the dye delivery system.
Autors: Stefanie Heizmann;Antje Kilias;Patrick Ruther;Ulrich Egert;Maria Asplund;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Feb 2018, volume: 26, issue:2, pages: 299 - 306
Publisher: IEEE
 
» Active Control of Magnetic Field Using eDMP Model for Biomedical Applications
Abstract:
This paper presents a novel method to actively control magnetic field in a region-of-interest using multiple electromagnets (EMs), referred to here as extended distributed multipole (eDMP). Numerous sensor and actuator applications require controlling magnetic fields such as medical device and automation. However, it is difficult to achieve owing to the nonlinearity of the field and its interaction with various materials. In this paper, the eDMP model is used to compute the magnetic field of the EMs. The method achieves fast and accurate field analysis and it can be utilized to control the desired magnetic field using a set of EMs. The magnetic field generated from various designs of EMs and control of the field is numerically simulated and compared with experiments. Finally, two practical applications are presented to show the effectiveness and accuracy of the method. The first is a transcranial magnetic stimulation (TMS) paradigm used by a medical instrument for diagnosis and treatment of brain disease using magnetic pulses. The effect of the TMS coils on performance is investigated with the eDMP method. The second refers to the locomotion control of a capsule endoscope. Magnetic locomotion can be controlled to attain a desired position and orientation. Simulations and experimental results justify the usefulness of the method that is expected to be extensively applicable.
Autors: Jiyun Jeon;Hungsun Son;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Feb 2018, volume: 23, issue:1, pages: 29 - 37
Publisher: IEEE
 
» Active Control Transmission of Terahertz Metamaterials Based on Ion Implantation and Light Pumping
Abstract:
A method (ion-implantation) that can control surface carrier density of silicon wafer in silicon fabrication industry is combined with metamaterial to demonstrate a new way to control response of metamaterial transmission operating at terahertz frequency. Ion-implantation which is the most exact and easy way to control carriers of silicon wafer is used to fabricate a stable response of transmission metamaterial. Therefore, a split-ring resonators (SRRs) metamaterial is designed and fabricated to investigate the relationship between carrier density, power of pumping light, and transmission. Meanwhile, the numerical simulation was carried out to verify the experimental results. The relationship between the simulation results and experiments results was confirmed. This method could be a potential way to make stable response of metamaterial, which could be switcher, filter, and terahertz detectors.
Autors: Zhaoxin Geng;Xiong Zhang;Jian Liu;
Appeared in: IEEE Photonics Journal
Publication date: Feb 2018, volume: 10, issue:1, pages: 1 - 8
Publisher: IEEE
 
» Active Stiffness Tuning of a Spring-Based Continuum Robot for MRI-Guided Neurosurgery
Abstract:
Deep intracranial tumor removal can be achieved if the neurosurgical robot has sufficient flexibility and stability. Toward achieving this goal, we have developed a spring-based continuum robot, namely a minimally invasive neurosurgical intracranial robot (MINIR-II) with novel tendon routing and tunable stiffness for use in a magnetic resonance imaging (MRI) environment. The robot consists of a pair of springs in parallel, i.e., an inner interconnected spring that promotes flexibility with decoupled segment motion and an outer spring that maintains its smooth curved shape during its interaction with the tissue. We propose a shape memory alloy (SMA) spring backbone that provides local stiffness control and a tendon routing configuration that enables independent segment locking. In this paper, we also present a detailed local stiffness analysis of the SMA backbone and model the relationship between the resistive force at the robot tip and the tension in the tendon. We also demonstrate through experiments, the validity of our local stiffness model of the SMA backbone and the correlation between the tendon tension and the resistive force. We also performed MRI compatibility studies of the three-segment MINIR-II robot by attaching it to a robotic platform that consists of SMA spring actuators with integrated water cooling modules.
Autors: Yeongjin Kim;Shing Shin Cheng;Jaydev P. Desai;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 18 - 28
Publisher: IEEE
 
» Adaptive Cancellation of Static and Dynamic Mismatch Error in Continuous-Time DACs
Abstract:
Inadvertent but inevitable mismatches among nominally identical unit element 1-bit digital-to-analog converters (DACs) within a multi-bit Nyquist-rate DAC cause both static and dynamic error in the DAC’s continuous-time output waveform. Prior calibration techniques are able to suppress static mismatch error, but have had limited success in suppressing dynamic mismatch error. This paper presents a digital calibration technique that adaptively measures and cancels both static and dynamic mismatch error over the DAC’s first Nyquist band. The technique is capable of either foreground or background operation, and is relatively insensitive to non-ideal circuit behavior. The paper presents a rigorous mathematical analysis of the technique, and demonstrates the results of the paper with both behavioral and transistor-level circuit simulations.
Autors: Derui Kong;Ian Galton;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2018, volume: 65, issue:2, pages: 421 - 433
Publisher: IEEE
 
» Adaptive Cell Zooming and Sleeping for Green Heterogeneous Ultradense Networks
Abstract:
With the increasingly dense-deployed small cells, the heterogeneous ultradense network (H-UDN) now faces new challenges. In order to fulfill user traffic demand and improve network energy efficiency in H-UDNs, this paper researches on the adaptive cell zooming scheme to achieve the optimized user association through adjusting cell coverages. Then, the cell sleeping scheme is further applied to turn off light traffic load cells for base station (BS) power saving. We define the cell zooming factor (CZF) to express cell coverage, which is derived as a closed-form expression with the relationship of small cell and macro cell densities. The user association probability with one typical cell is also derived, where the probability is related with both the transmission power and CZF. We apply the game theory to optimize the CZF based on reduction of area power consumption. Based on the fact that users are encouraged to associate with small cells to reduce transmission power consumptions, the small cell sleeping scheme is further applied to improve the network energy efficiency, while the sleeping small cell users could be offloaded to macro cells. The sleeping probability is defined and derived with influences of different sleeping thresholds. We optimize the threshold with maximized energy saving performance. Simulation results verify that the sleeping threshold has an optimized value.
Autors: Xiaodong Xu;Chunjing Yuan;Wenwan Chen;Xiaofeng Tao;Yan Sun;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Feb 2018, volume: 67, issue:2, pages: 1612 - 1621
Publisher: IEEE
 
» Adaptive Coding and Modulation for Large-Scale Antenna Array-Based Aeronautical Communications in the Presence of Co-Channel Interference
Abstract:
In order to meet the demands of “Internet above the clouds,” we propose a multiple-antenna aided adaptive coding and modulation (ACM) for aeronautical communications. The proposed ACM scheme switches its coding and modulation mode according to the distance between the communicating aircraft, which is readily available with the aid of the airborne radar or the global positioning system. We derive an asymptotic closed-form expression of the signal-to-interference-plus-noise ratio (SINR) as the number of transmitting antennas tends to infinity, in the presence of realistic co-channel interference and channel estimation errors. The achievable transmission rates and the corresponding mode-switching distance-thresholds are readily obtained based on this closed-form SINR formula. Monte-Carlo simulation results are used to validate our theoretical analysis. For the specific example of 32 transmit antennas and four receive antennas communicating at a 5-GHz carrier frequency and using 6-MHz bandwidth, which are reused by multiple other pairs of communicating aircraft, the proposed distance-based ACM is capable of providing as high as 65.928-Mb/s data rate when the communication distance is less than 25 km.
Autors: Jiankang Zhang;Sheng Chen;Robert G. Maunder;Rong Zhang;Lajos Hanzo;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Feb 2018, volume: 17, issue:2, pages: 1343 - 1357
Publisher: IEEE
 
» Adaptive Compensation of Multiple Actuator Faults for Two Physically Linked 2WD Robots
Abstract:
This short paper develops an adaptive compensation control scheme for two physically linked two-wheel-drive mobile robots with multiple actuator faults. Kinematic and dynamic models are first proposed. Then, an adaptive control scheme is designed, which ensures system stability and asymptotic tracking properties. Simulation results verify its effectiveness.
Autors: Yajie Ma;Vincent Cocquempot;Maan El Badaoui El Najjar;Bin Jiang;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2018, volume: 34, issue:1, pages: 248 - 255
Publisher: IEEE
 
» Adaptive Fault-Tolerant Attitude Tracking Control of Spacecraft With Prescribed Performance
Abstract:
The science objectives of a spacecraft mission place stringent performance requirements on the spacecraft attitude control system. However, it remains an open problem how to guarantee consistent control performance necessary to meet these requirements, especially in the event of actuator faults and input saturation. Motivated by this fact, in this paper, we address the problem of attitude tracking control with prescribed performance guarantees for a rigid spacecraft subject to unknown but constant inertia parameters, unexpected disturbances, actuator faults, and input saturation. First, certain performance functions specified a priori by the designer are adopted to impose desired performance metrics on the attitude tracking errors. Then, the original attitude tracking error dynamics with performance constraints is transformed into an equivalent “state-constrained” one whose robust stabilization is shown to be sufficient to solve the stated problem via a novel error transformation. Subsequently, based on the transformed system, an adaptive fault-tolerant controller is derived by incorporating backstepping control, the barrier Lyapunov function, and Nussbaum gains. It is proved that the designed controller is able to guarantee the satisfaction of the prespecified constraints on the transformed errors, as well as the boundedness of all other closed-loop signals, without resorting to a judicious selection of the control parameters. Finally, the effectiveness of the proposed control scheme is evaluated by means of simulation experiments carried out on a microsatellite.
Autors: Qinglei Hu;Xiaodong Shao;Lei Guo;
Appeared in: IEEE/ASME Transactions on Mechatronics
Publication date: Feb 2018, volume: 23, issue:1, pages: 331 - 341
Publisher: IEEE
 

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  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