Electrical and Electronics Engineering publications abstract of: 11-2017 sorted by title, page: 2

» A Regression Method Based on Noninvasive Clinical Data to Predict the Mechanical Behavior of Ascending Aorta Aneurysmal Tissue
Abstract:
Goal: Ascending aorta aneurysms represent a severe life-threatening condition associated with asymptomatic risk of rupture. Prediction of aneurysm evolution and rupture is one of the hottest investigation topics in cardiovascular science, and the decision on when and whether to surgically operate is still an open question. We propose an approach for estimating the patient-specific ultimate mechanical properties and stress–stretch characteristics based on noninvasive data. Methods: As for the characteristics, we consider a nonlinear constitutive model of the aortic wall and assume patient-specific model coefficients. Through a regression model, we build the response surfaces of ultimate stress, ultimate stretch, and model coefficients in function of patient data that are commonly available in the clinical practice. We apply the approach to a dataset of 59 patients. Results: The approach is fair and accurate response surfaces can be obtained for both ultimate properties and model coefficients. Conclusion: Prediction errors are acceptable, even though a larger patient dataset will be required to stabilize the surfaces, making it possible to apply the approach in the clinical practice. Significance: A fair prediction of the patient aortic mechanical behavior, based on clinical information noninvasively acquired, would improve the decision process and lead to more effective treatments.
Autors: Ferdinando Auricchio;Anna Ferrara;Ettore Lanzarone;Simone Morganti;Pasquale Totaro;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Nov 2017, volume: 64, issue:11, pages: 2607 - 2617
Publisher: IEEE
 
» A Resistant Strain: Revealing the Online Grassroots Rise of the Antivaccination Movement
Abstract:
An analysis of more than eight years of data from vaccination forums on mothering.com shows that the antivaccination movement is well-organized and widely dispersed, and that it emerged long before concerns about immunity were expressed. The findings are evidence of a formidable challenge to the social norms surrounding vaccination.
Autors: Roja Bandari;Zicong Zhou;Hai Qian;Timothy R. Tangherlini;Vwani P. Roychowdhury;
Appeared in: Computer
Publication date: Nov 2017, volume: 50, issue:11, pages: 60 - 67
Publisher: IEEE
 
» A Resource Allocation Mechanism Using Matching and Bargaining
Abstract:
A resource allocation mechanism based on matching and bargaining is presented. There are many resource providers and many resource seekers. The resource valuations of the agents are private and are uniformly distributed over a common support. The regulator establishes two bid levels. Each participating agent is randomly paired with a counterpart and the allocations arise out of these bilateral encounters based on agents’ individual bid choices. We show a Bayes Nash equilibrium in dominant strategy when the regulator fixes the strategy for one set of agents. The mechanism has parameters to tune the allocations.
Autors: Swapan Sikdar;Sidney Givigi;Karen Rudie;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5909 - 5914
Publisher: IEEE
 
» A Rise-Dimensional Modeling and Estimation Method for Flight Trajectory Error in Bistatic Forward-Looking SAR
Abstract:
Bistatic forward-looking synthetic aperture radar (BFSAR) is a kind of bistatic SAR system that can image forward-looking terrain in the flight direction of a moving platform. In BFSAR, compensation of the flight trajectory errors is of great significance to get a well-focused image. To accomplish an accurate motion compensation in image processing, a high-precision navigation system is needed. However, in many cases, due to the accuracy limit of such systems, flight trajectory errors are hard to be compensated correctly, causing mainly the resolution decrease in final images. In order to cope with such a problem, we propose a rise-dimensional modeling and estimation for flight trajectory error based on raw BFSAR data in this paper. To apply this method, we first carry out a preprocessing named azimuth-slowtime decoupling to deal with the spatially variant flight trajectory error before estimation. Then, an optimization model for flight trajectory estimation under the criterion of maximum image intensity is built. The solution to the optimization model is the accurate flight trajectory. Then, block coordinate descent technique is used to solve this optimization model. The processing of BFSAR data shows that the algorithm can obtain a more accurate estimation results, and generate better focused images compared with the existing trajectory estimation method.
Autors: Wei Pu;Junjie Wu;Yulin Huang;Ke Du;Wenchao Li;Jianyu Yang;Haiguang Yang;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 5001 - 5015
Publisher: IEEE
 
» A Robust Bisection-Based Estimator for TOA-Based Target Localization in NLOS Environments
Abstract:
This letter addresses the problem of target localization in harsh indoor environments based on range measurements. To mitigate the non-line-of-sight (NLOS) bias, we propose a novel robust estimator by transforming the localization problem into a generalized trust region sub-problem framework. Although still non-convex in general, this class of problems can be readily solved exactly by means of bisection procedure. The new approach does not require to make any assumptions about the statistics of NLOS bias, nor to try to distinguish which links are NLOS and which are not. Unlike the existing algorithms, the computational complexity of the proposed algorithm is linear in the number of reference nodes. Our simulation results corroborate the effectiveness of the new algorithm in terms of NLOS bias mitigation and show that the performance of our estimator is highly competitive with the performance of the state-of-the-art algorithms. In fact, they show that the novel estimator outperforms slightly the existing ones in general, and that it always provides a feasible solution.
Autors: Slavisa Tomic;Marko Beko;Rui Dinis;Paulo Montezuma;
Appeared in: IEEE Communications Letters
Publication date: Nov 2017, volume: 21, issue:11, pages: 2488 - 2491
Publisher: IEEE
 
» A Robust Yaw and Pitch Estimation Method for Mini-InSAR System
Abstract:
For the mini-interferometric synthetic aperture radar system mounted on small aircraft or unmanned aerial vehicles, yaw and pitch angle deviations can be considerably high due to their small size and atmospheric turbulence. Moreover, we cannot install a large-volume, heavy-weight, and high-cost inertial navigation system limited by the aircraft’s carrying capacity and system cost. In view of the problem, this letter proposes a robust yaw and pitch angle estimation method based on the relationship between range-variant Doppler centroid and attitude angles. For each azimuth moment, estimate the range-variant Doppler centroid for each range gate and solve the range-variant Doppler centroid model using a total least squares method to obtain a robust yaw and pitch angle estimation result. The comparison of the estimated and recorded yaw and pitch angles by a high-accuracy position and orientation system validated the effectiveness and reliability of our proposed yaw and pitch angle estimation method.
Autors: Xikai Fu;Maosheng Xiang;Bingnan Wang;Shuai Jiang;Xiaofan Sun;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 2157 - 2161
Publisher: IEEE
 
» A Saliency Prior Context Model for Real-Time Object Tracking
Abstract:
Real-time object tracking has wide applications in time-critical multimedia processing areas such as motion analysis and human–computer interaction. It remains a hard problem to balance between accuracy and speed. In this paper, we present a fast real-time context-based visual tracking algorithm with a new saliency prior context (SPC) model. Based on the probability formulation, the tracking problem is solved by sequentially maximizing the computed confidence map of target location in each video frame. To handle the various cases of feature distributions generated from different targets and their contexts, we exploit low-level features as well as fast spectral analysis for saliency to build a new prior context model. Then, based on this model and a spatial context model learned online, a confidence map is computed and the target location is estimated. In addition, under this framework, the tracking procedure can be accelerated by the fast Fourier transform. Therefore, the new method generally achieves a real-time running speed. Extensive experiments show that our tracking algorithm based on the proposed SPC model achieves real-time computation efficiency with overall best performance comparing with other state-of-the-art methods.
Autors: Cong Ma;Zhenjiang Miao;Xiao-Ping Zhang;Min Li;
Appeared in: IEEE Transactions on Multimedia
Publication date: Nov 2017, volume: 19, issue:11, pages: 2415 - 2424
Publisher: IEEE
 
» A Screening Rule-Based Iterative Numerical Method for Observability Analysis
Abstract:
Observability analysis determines whether a unique system state estimate can be obtained for a given set of measurements, i.e., if the system is fully observable. It is an essential requirement for robust power system state estimation and may be carried out offline to determine whether a measurement configuration is adequate, or online to ensure that any changes in the available measurements (e.g., communication or meter failures) have not created isolated observable islands. One aspect of observability analysis is identifying the observable islands, i.e., the subnetworks within the power system in which the states can still be uniquely estimated with the measurements available. The existing numerical methods for observability analysis are noniterative, but fail to correctly identify the observable islands in certain cases. In this paper, the flaw in the underlying theorems behind these existing methods has been identified and a new iterative method is presented that overcomes it. However, online observability analysis is time sensitive, so iterative methods are undesirable. Therefore, a pathological case identification rule (PCIR) is proposed that allows the iterative procedure to be terminated early, if iterations are no longer necessary to prevent an incorrect identification. Furthermore, the new PCIR allows direct identification of observable islands, which allows the proposed iterative method to be faster than the existing noniterative methods. The proposed iterative method and the PCIR are based on mathematical proofs and explained with numerical examples, while the speed improvement from direct island identification is demonstrated using simulations of the IEEE 14 and 2736 bus test systems.
Autors: Zhaoyang Jin;Papiya Dattaray;Peter Wall;James Yu;Vladimir Terzija;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4188 - 4198
Publisher: IEEE
 
» A Secure Approach for Caching Contents in Wireless Ad Hoc Networks
Abstract:
Caching aims to store data locally in some nodes within the network to be able to retrieve the contents in shorter time periods. However, caching in the network did not always consider secure storage (due to the compromise between time performance and security). In this paper, a novel decentralized secure coded caching approach is proposed. In this solution, nodes only transmit coded files to avoid eavesdropper wiretappings and protect the user contents. In this technique random vectors are used to combine the contents using XOR operation. We modeled the proposed coded caching scheme by a Shannon cipher system to show that coded caching achieves asymptotic perfect secrecy. The proposed coded caching scheme significantly simplifies the routing protocol in cached networks while it reduces overcaching and achieves a higher throughput capacity compared to uncoded caching in reactive routing. It is shown that with the proposed coded caching scheme any content can be retrieved by selecting a random path while achieving asymptotic optimum solution. We have also studied the cache hit probability and shown that the coded cache hit probability is significantly higher than uncoded caching. A secure caching update algorithm is also presented.
Autors: Mohsen Karimzadeh Kiskani;Hamid R. Sadjadpour;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10249 - 10258
Publisher: IEEE
 
» A Semantic Web Approach to Simplifying Trigger-Action Programming in the IoT
Abstract:
End-user programming environments for the IoT such as IFTTT rely on a multitude of low-level trigger-action rules that categorize devices and services by technology or brand. EUPont is a Semantic Web ontology that enables users to meet their needs with fewer, higher-level rules that can be adapted to different contextual situations and as-yet-unknown IoT devices and services.
Autors: Fulvio Corno;Luigi De Russis;Alberto Monge Roffarello;
Appeared in: Computer
Publication date: Nov 2017, volume: 50, issue:11, pages: 18 - 24
Publisher: IEEE
 
» A Sharpening of the Welch Bounds and the Existence of Real and Complex Spherical $t$ –Designs
Abstract:
The Welch bounds for a finite set of unit vectors are a family of inequalities indexed by , which describe how “evenly spread” the vectors are. They have important applications in signal analysis, where sequences giving equality in the first Welch bound are known as Welch bound equality sequences or as unit norm tight frames. Here, we consider sequences of vectors giving equality in the higher order Welch bounds. These are seen to correspond to tight frames for the complex symmetric –tensors (which we prove always exist). We show that for , the Welch bounds can be sharpened for real vectors, and again, vectors giving equality always exist. We give a unified treatment of various conditions for equality in both the real and complex cases. In particular, we give an explicit description of the corresponding cubature rules (–designs). Our results set up a framework for the construction and classification several configurations of vectors of recent interest. These include mutually unbiased bases, complex equiangular lines, spherical half–designs, projective –designs, and minimisers of the higher order frame potential. One interesting consequence is a construction of sets of complex equiangular lines, which were previously unknown.
Autors: Shayne Waldron;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 6849 - 6857
Publisher: IEEE
 
» A Si-Compatible Fabrication Process for Scaled Self-Aligned InGaAs FinFETs
Abstract:
We have developed a scalable gate-last process to fabricate self-aligned InGaAs FinFETs that relies on extensive use of dry etch. The process involves F-based dry etching of refractory metal ohmic contacts that are formed early in the process. The fins are etched in a novel inductive coupled plasma process using BCl3/SiCl4/Ar. High aspect ratio fins with smooth sidewalls are obtained. To further improve the quality of the sidewalls and shrink the fin width, digital etch is used. Through this process flow, we have demonstrated FinFETs with nm and fin width as narrow as 7 nm with high yield. Good electrostatic characteristics are obtained in a wide range of device dimensions. In devices with 7 nm fin width, record channel aspect ratio, and transconductance per unit footprint are obtained.
Autors: A. Vardi;J. Lin;W. Lu;X. Zhao;A. Fernando-Saavedra;J. A. del Alamo;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Nov 2017, volume: 30, issue:4, pages: 468 - 474
Publisher: IEEE
 
» A Sierpinski Space-Filling Clock Tree Using Multiply-by-3 Fractal-Coupled Ring Oscillators
Abstract:
A space-filling clock tree is presented, which takes an advantage of LC resonant clocking, to obtain a uniform phase and amplitude multiply-by-3 clock from a unique Sierpinski-coupled ring oscillator (SCRO) array. The three-stage interleaved SCROs resemble the Sierpinski triangle, and are synchronized with a common frequency to all. The SCRO further provides an aligned output phase relationship to reduce skew. The triangle clock grid with a side length of 3.2 mm is filled by a space-filling clock tree. The 3-D stacked transformers at the tree endpoints extract the third harmonic of the SCRO array oscillation and scale the voltage amplitude of the extracted clock. The transformers also perform a built-in bandpass filtering function to remove injected noise. An experimental prototype integrated in a 90-nm CMOS operates at 2.85–4.3 GHz and consumes 19.2–49 mW under 0.7–1 V supply voltages. With 300-mV added supply noise, jitter was measured as 3.4 ps (rms) and 17.7 ps (pp). The measured results reveal substantial improvements in both power and jitter from this approach.
Autors: Yi-Wei Lin;Shawn S. H. Hsu;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Nov 2017, volume: 52, issue:11, pages: 2947 - 2962
Publisher: IEEE
 
» A Simple Frequency-Agile Bandpass Filter With Predefined Bandwidth and Stopband Using Synchronously Tuned Dual-Mode Resonator
Abstract:
This letter proposes a novel and simple synchronously tuned dual-mode resonator (STDR) to achieve a frequency-agile bandpass filter (FA-BPF) with predefined bandwidth (BW) location, BW variation, and stopband characteristics. This solution overcomes the difficulty with predefining the BW of previous tunable filter designs. The proposed STDR is controlled by two varactors and a single bias. The two resonant frequencies’ separation of the resonator can be adjusted by changing the varactor loading position and the shorted stub length. Meanwhile, the transmission zero location can be predefined by specifying the corresponding dimensions. Based on the predefined STDR, the FA-BPF can be achieved easily. An FA-BPF with a constant BW is realized to demonstrate such a unique feature. The measurement results of the FA-BPF verify the theory, and also exhibit high selectivity, wide frequency tuning range, and simple design/ control procedure.
Autors: Di Lu;N. Scott Barker;Xiaohong Tang;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Nov 2017, volume: 27, issue:11, pages: 983 - 985
Publisher: IEEE
 
» A Simple Miller Compensation With Essential Bandwidth Improvement
Abstract:
A novel technique for adaptive frequency compensation in negative feedback amplifiers is proposed. It is demonstrated that a simple reconnection of the compensation capacitor in a two-stage Miller op-amp leads to a pseudoconstant bandwidth for a moderate range of closed-loop gains, without requiring additional power dissipation or extra silicon area. Also, an improvement of power-supply rejection ratio is obtained. The presented technique has been applied to a non-inverting amplifier, which has been fabricated in a 0.18- CMOS process. Measurement results validating the proposed compensation scheme are provided.
Autors: José M. Algueta-Miguel;Jaime Ramirez-Angulo;Enrique Mirazo;Antonio J. Lopez-Martin;Ramón Gonzalez Carvajal;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3186 - 3192
Publisher: IEEE
 
» A Simplified Finite-Element Model of Hybrid Excitation Synchronous Machines With Radial/Axial Flux Paths via Magnetic Equivalent Circuit
Abstract:
In this paper, a novel modeling method for hybrid excitation synchronous machines (HESMs) with radial/axial flux paths via magnetic equivalent circuit (MEC) is proposed. 3-D finite-element analysis (FEA) is essential when analyzing a machine with radial/axial flux paths due to the asymmetry in the axial direction. However, 3-D FEA is computationally expensive and time-consuming, especially during the preliminary design stage. The proposed modeling method is analyzed and validated based on an HESM with magnetic shunting rotor. The fundamental structure and working principle of the HESM with magnetic shunting rotor are introduced. On the basis of 3-D structure, an MEC considering saturation and leakage flux distribution is built and illustrated, as well as field analysis is performed. A 2-D equivalent finite-element model via MEC is built and illustrated. A prototype HESM with magnetic shunting rotor has been designed by the proposed modeling method and developed for experimental verification. With the proposed modeling method, the computational efficiency is significantly improved in the design stage. The proposed modeling method is verified by the good agreement between the predicted and measured results.
Autors: Ye Liu;Zhuoran Zhang;Weiwei Geng;Jincai Li;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» A Simplified Model for the Retrieval of Precipitable Water Vapor From GPS Signal
Abstract:
In this paper, a simplified latitude and day-of-year (DoY)-based model is proposed for the retrieval of precipitable water vapor (PWV) from global positioning system (GPS) signal. Conventionally, PWV, the total amount of water in a vertical column of a unit cross-sectional area, is estimated from the GPS signal delay and a dimensionless conversion factor PI. This PI value is found to rely on a water vapor weighted mean temperature (Tm) value which varies widely across the day, month, and year for different regions. It is, therefore, both time specific and site specific. Analysis of the PI value and its effect on the retrieved PWV from the data obtained for tropical, subtropical, and temperate regions show that although the PI value is time and site specific, the change in the median value of PI for different years is minimal and is dependent only on factors like the latitude coordinates of the particular site and the DoY. Therefore, using the data obtained from 174 different sites, a latitude-coordinate and DoY-based PI value model for the retrieval of PWV is proposed in this paper. The proposed model has been successfully validated using data from different databases: the International GNSS Service Global Positioning System National Aeronautics and Space Administration (IGS GPS NASA) database, the International GNSS Service Global Positioning System Global Geodetic Observing System (IGS GPS GGOS) database, and the very-long-baseline interferometry (VLBI) database. Results show strong agreement between PWV values calculated using the proposed model and those calculated using the temperature dependent models with 99%, 98%, and 93% of error within ±1 mm for IGS GPS NASA, IGS GPS GGOS, and VLBI databases, respectively. Moreover, the proposed model allows for the ease of PWV retrieval, which is useful in meteorological studies and also applicable in satellite communi- ations.
Autors: Shilpa Manandhar;Yee Hui Lee;Yu Song Meng;Jin Teong Ong;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Nov 2017, volume: 55, issue:11, pages: 6245 - 6253
Publisher: IEEE
 
» A Single-Channel EOG-Based Speller
Abstract:
Electrooculography (EOG) signals, which can be used to infer the intentions of a user based on eye movements, are widely used in human–computer interface (HCI) systems. Most existing EOG-based HCI systems incorporate a limited number of commands because they generally associate different commands with a few different types of eye movements, such as looking up, down, left, or right. This paper presents a novel single-channel EOG-based HCI that allows users to spell asynchronously by only blinking. Forty buttons corresponding to 40 characters displayed to the user via a graphical user interface are intensified in a random order. To select a button, the user must blink his/her eyes in synchrony as the target button is flashed. Two data processing procedures, specifically support vector machine (SVM) classification and waveform detection, are combined to detect eye blinks. During detection, we simultaneously feed the feature vectors extracted from the ongoing EOG signal into the SVM classification and waveform detection modules. Decisions are made based on the results of the SVM classification and waveform detection. Three online experiments were conducted with eight healthy subjects. We achieved an average accuracy of 94.4% and a response time of 4.14 s for selecting a character in synchronous mode, as well as an average accuracy of 93.43% and a false positive rate of 0.03/min in the idle state in asynchronous mode. The experimental results, therefore, demonstrated the effectiveness of this single-channel EOG-based speller.
Autors: Shenghong He;Yuanqing Li;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 1978 - 1987
Publisher: IEEE
 
» A Single-Crystal Mössbauer Study of Spin Reorientations in the Multi-Ferroic HoFeO3
Abstract:
57Fe Mössbauer spectroscopy on single crystal slices has been used to study the spin reorientation transition that occurs in HoFeO3 for K. We also prepared a powder sample for comparison and confirmed that the results were consistent between the two data sets. By using thin polished slices cut perpendicular to the three orthorhombic axes we have been able to follow --axis reorientation in detail and confirm that moments also tip toward the −axis by ~ 20° before returning closer to the −plane. We also show that the moments are never fully parallel or perpendicular to any of the three orthorhombic axes; a consequence of the mixed ferro-/antiferro-magnetic structure adopted by HoFeO3.
Autors: D. H. Ryan;Quentin Stoyel;Larissa Veryha;Kai Xu;Wei Ren;Shixun Cao;Zahra Yamani;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» A Soft Four Degree-of-Freedom Load Cell Based on the Hall Effect
Abstract:
This paper presents the design of a soft four degree-of-freedom load cell that is robust and light-weight and can be integrated into robotic applications. The sensor measures three axes of force and a single axis of torque about the central axis. The sensor is comprised of a magnet suspended within an elastomer above two three-axis Hall effect sensors. As a load is applied, the magnet is displaced within the elastomer that results in changes in the magnetic flux density at the locations of the two Hall effect sensors. Experimental measurements of magnetic flux density within the area of interest were used to formulate analytical expressions to relate magnet field strength to the position of the magnet. The displacement and orientation measurements combined with the material properties of the elastomer are used to calibrate and calculate the applied load. The ability to measure the three degrees-of-freedom force and axial torque was evaluated with combined loading applied by a robotic arm. The decoupled results show the four degree-of-freedom load cell can distinguish three axes of force and one axis of torque with 6.9% average error for normal force, 4.3% and 2.6% average error for shear force in the - and -axes, respectively. There was 8.6% average error for the torque.
Autors: Qiandong Nie;Frank C. Sup;
Appeared in: IEEE Sensors Journal
Publication date: Nov 2017, volume: 17, issue:22, pages: 7355 - 7363
Publisher: IEEE
 
» A Soft-5/6 Modulation Code With Iterative ITI Subtraction Scheme in Multireader TDMR Systems
Abstract:
The huge growth of the consumer electronic industry is driving the need for achieving ultrahigh areal storage densities. 2-D magnetic recording is a promising high-density storage technology where the shingled writing technique is employed for increasing the track per inch (TPI) and achieving higher areal densities. Nevertheless, high TPI causes a reader to cover higher number of tracks, which leads to the intertrack interference (ITI); hence the system performance is severely deteriorated. Therefore, we first propose the soft-5/6 modulation code together with iterative ITI subtraction scheme. Here, the soft information encoding and decoding schemes operate based on Boolean logic circuit for using in the iterative system. Furthermore, we also propose to move the upper and lower readers closer to the center reader to avoid the ITI effect from their outer tracks, which will then be performed together with ITI subtraction scheme. Moreover, this proposed reading technique is also applied together with the soft-4/5 modulation code. The simulation results show that the proposed systems are superior to the conventional system, especially at high user density.
Autors: Kotchakorn Pituso;Chanon Warisarn;Damrongsak Tongsomporn;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» A Software-Defined Green Framework for Hybrid EV-Charging Networks
Abstract:
EVs provide a promising green solution to reduce dependence on fossil fuel and the emission of greenhouse gas. This article concerns hybrid EV systems that contain both wired charging and wireless charging vehicles. To the best of our knowledge, we are the first to discuss how to jointly use these two types of charging methods whose advantages are complementary to each other; for example, wireless charging has better user friendliness and flexibility, while wired charging can provide higher charging efficiency and bidirectional energy transmission. We believe such a hybrid system can benefit us much more than either a pure wireless or pure wired EV charging system. On the other hand, we also pay attention to a practically important problem with DSM. The existing schemes can hardly ensure efficient and stable charging services in the foreseeable future due to the rapidly increasing number of electric vehicles and the limited capacity of local grids. To address this issue, we propose a software-defined green framework for hybrid EV charging networks, which consists of three planes: the application plane provides customized services for users; the control plane aims to guide both data flow and energy flow to implement an efficient and economic strategy for EV charging; and the physical plane collects the information from a large number of EVs and other infrastructures. Furthermore, we present a DSM approach for EV charging as a case study. Simulation results reveal that our proposals could achieve delightful DSM performance in the proposed software-defined EV charging networks. Although the proposed hybrid framework offers promising opportunities, we still face some technical challenges that solicit further research efforts from both academia and industry, which are discussed in detail at the end of this article.
Autors: Yanfei Sun;Xiaoxuan Hu;Xiulong Liu;Xiaoming He;Kun Wang;
Appeared in: IEEE Communications Magazine
Publication date: Nov 2017, volume: 55, issue:11, pages: 62 - 69
Publisher: IEEE
 
» A Sparse Linear Model and Significance Test for Individual Consumption Prediction
Abstract:
Accurate prediction of user consumption is a key part not only in understanding consumer flexibility and behavior patterns, but in the design of robust and efficient energy saving programs as well. Existing prediction methods usually have high relative errors that can be larger than 30% and have difficulties accounting for heterogeneity between individual users. In this paper, we propose a method to improve prediction accuracy of individual users by adaptively exploring sparsity in historical data and leveraging predictive relationship between different users. Sparsity is captured by popular least absolute shrinkage and selection estimator, while user selection is formulated as an optimal hypothesis testing problem and solved via a covariance test. Using real-world data from PG&E, we provide extensive simulation validation of the proposed method against well-known techniques such as support vector machine, principle component analysis combined with linear regression, and random forest. The results demonstrate that our proposed methods are operationally efficient because of linear nature, and achieve optimal prediction performance.
Autors: Pan Li;Baosen Zhang;Yang Weng;Ram Rajagopal;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4489 - 4500
Publisher: IEEE
 
» A Spatial Modulation With Space-Phase Constellation for Spatially Correlated Channels
Abstract:
We design a spatial modulation (SM) scheme for spatially correlated channels under the constraints of a single radio frequency chain transmitter and open-loop transmission. To alleviate the performance degradation of the conventional SM in highly correlated channels, the proposed SM scheme adopts the antenna grouping and a new space-phase constellation, which is designed by considering the phase-only constraint and received symbol distance in fully correlated channels. In the simulation results, the proposed scheme achieves about 2.5-dB gain at bit error rate of compared with the conventional SM in highly correlated channels.
Autors: Yongjin Ahn;Hoondong Noh;Chungyong Lee;
Appeared in: IEEE Communications Letters
Publication date: Nov 2017, volume: 21, issue:11, pages: 2396 - 2399
Publisher: IEEE
 
» A Spherical Active Coded Aperture for $4pi $ Gamma-Ray Imaging
Abstract:
Gamma-ray imaging facilitates the efficient detection, characterization, and localization of compact radioactive sources in cluttered environments. Fieldable detector systems employing active planar coded apertures have demonstrated broad energy sensitivity via both coded aperture and Compton imaging modalities. However, planar configurations suffer from a limited field of view, especially in the coded aperture mode. To improve upon this limitation, we introduce a novel design by rearranging the detectors into an active coded spherical configuration, resulting in a isotropic field of view for both coded aperture and Compton imaging. This paper focuses on the low-energy coded aperture modality and the optimization techniques used to determine the optimal number and configuration of 1-cm3 CdZnTe coplanar grid detectors on a 14-cm diameter sphere with 192 available detector locations.
Autors: Daniel Hellfeld;Paul Barton;Donald Gunter;Lucian Mihailescu;Kai Vetter;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Nov 2017, volume: 64, issue:11, pages: 2837 - 2842
Publisher: IEEE
 
» A Statistical Solution to Efficiently Optimize the Design of an Inverter-Fed Permanent-Magnet Motor
Abstract:
This paper provides the fundamentals of integrated motor-drive system design knowledge that could be used as a basis to change the existing machine design approach from being a separate machine design tool to a more advanced engineering package in which the inverter performance can also be considered. Various users' preferences including motor performances in the transient, rated, and flux-weakening operations along with the inverter quality are studied by means of a detailed cosimulation process which utilizes finite element method, MATLAB, and SIMULINK packages to build the framework based on which magnetic, electric, and electronic devices and quantities are modeled, simulated, and postprocessed. A case study of an interior-permanent-magnet motor connected to a field-oriented controlled drive is investigated and the design process concepts are developed by means of a comprehensive statistical analysis. It is shown that incorporating the inverter quality into the design process changes the idea of optimum motor design, and hence, not only the design parameters but also the expectations from motor performances have to be revised. In fact, an integrated motor-drive system design process regarding the best motor operations in the transient, rated, and flux-weakening modes is targeted with the purpose of addressing design challenges of interior-permanent-magnet motors. To this end, the start-up torque, the rise time, the motor efficiency, the torque ripple, the constant power speed range, the characteristic current, the inverter efficiency, and the system cost, which cover a group of important objectives of different applications, are investigated. Finally, a design package will be able to address different designers’ expectations more efficiently using the approach proposed herein.
Autors: Vahid Ghorbanian;David A. Lowther;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5315 - 5326
Publisher: IEEE
 
» A Study of the Effect of RRAM Reliability Soft Errors on the Performance of RRAM-Based Neuromorphic Systems
Abstract:
Resistive RAM (RRAM) device has been extensively used as a scalable nonvolatile memory cell in neuromorphic systems due to its several advantages, including its small size and low-power requirements. However, resulting from the stochastic nature of the oxygen vacancies, the RRAM device suffers from reliability soft errors. In this paper, we provide for the first time a modeling framework to compute the effect of those soft errors on the system accuracy. Applying the proposed technique on a case-study system used to recognize the MNIST data set, our simulation results show that the system accuracy can degrade from 91.6% to 43% due to the RRAM reliability soft errors. To overcome this loss in the system performance, various possible adjustments to the parameters of the neuron pulses are analyzed. Furthermore, in this paper, two methodologies are proposed for automatically detecting and fixing the degradation in the system accuracy caused by the RRAM reliability soft errors. Using the suggested methodologies, the system accuracy of our case-study system can be restored back from 43% to 91.6% with small increase in the training cycle duration and with as small as 0.1% increment in the energy consumption of the system.
Autors: Amr M. S. Tosson;Shimeng Yu;Mohab H. Anis;Lan Wei;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3125 - 3137
Publisher: IEEE
 
» A Study of Wind Direction Effects on Sea Surface Specular Scattering for GNSS-R Applications
Abstract:
A modeling study investigating the influence of wind direction on spaceborne global navigation satellite system reflectometry (GNSS-R) near-specular observations of the sea surface is reported. The study first focuses on a purely specular geometry under plane wave incidence, for which it is shown using the theorem of reciprocity and reflection symmetry that up-down wind variations are identically zero. It is also shown that “single-scattering” approximations of rough surface scattering predict no variations with wind direction of any kind for a purely specular geometry, while higher order approximations (such as the second-order small-slope approximation) can predict up/cross wind differences. Examples of these variations are reported and found to be small. Because the delay doppler maps (DDMs) measured in GNSS-R include some nonspecular contributions even for “specular” portions of the DDM, the second part of the study performs an examination of near-specular DDM variations with wind direction using the widely used geometrical optics approximation of surface scattering for a surface described with the non-Gaussian Cox–Munk slope probability density function. Variations with wind direction of the normalized radar cross section (NRCS) mapped onto the surface are examined, and again, it is shown that these variations are small for surface portions contributing to the near-specular portion of the DDM. In addition, it is shown that the dependencies of the bistatic NRCS on wind direction are such that differing portions of the surface “glistening zone” have differing phase shifts in their dependence on wind direction, causing the wind dependencies of the final near-specular DDM to be negligible. The final results of the study suggest that any wind direction dependence in spaceborne GNSS-R should be sought only in portions of the DDM away f- om the specular region. These results provide information to guide analyses of the wind direction information available in current GNSS-R missions such as TDS-1 and Cyclone Global Navigation Satellite System.
Autors: Jeonghwan Park;Joel T. Johnson;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 4677 - 4685
Publisher: IEEE
 
» A Study on Analytical Methods of FEM-Based Edge Heating System
Abstract:
This paper focuses on analytical methods of a finite-element method (FEM)-based edge heating system. The edge heating system plays a role in maintaining the temperature in the hot rolling process of carbon steel. Carbon steel moves along the production line and maintains the temperature by the edge heating system in the process. Power-of-the-edge heating system is transmitted to carbon steel during the process. Eddy currents are generated in carbon steel by Faraday’s law of electromagnetic induction, and eddy current loss serves as a heat source to increase the temperature. Thus, there is a need for accurate electromagnetic-field analysis and thermal analysis because the eddy current path generated in carbon steel greatly affects the heat distribution in carbon steel. This multiphysics analysis requires high reliability. Accordingly, this paper presents a coupling analysis method using an FEM-based coordinate mapping method as a more accurate analytical method. This paper also established an analytical approach to the edge heating system using the ductility analytical method of this coordinate mapping method.
Autors: Geochul Jeong;Youngmin Yang;Jae-Nam Bae;Ju Lee;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» A Study on Lunar Regolith Quantitative Random Model and Lunar Penetrating Radar Parameter Inversion
Abstract:
Lunar penetrating radar (LPR) is an important way to evaluate the geological structure of the subsurface of the moon. The Chang’E-3 has utilized LPR, which is equipped on the lunar rover named Yutu, to obtain the shallow lunar regolith structure in Mare Imbrium. The previous result provides a unique opportunity to map the subsurface structure and vertical distribution of the lunar regolith with high resolution. In order to evaluate the LPR data, the study of lunar regolith media is of great significance for understanding the material composition of the lunar regolith structure. In this letter, we focus on the lunar regolith quantitative random model and parameter inversion with LPR synthetic data. First, based on the Apollo drilling core data, we build the lunar regolith quantitative random model with clipped Gaussian random field theory. It can be used to model the discrete-valued random field with a given correlation structure. Then, we combine radar wave impedance and stochastic inversion methods to carry out LPR data inversion and parameter estimation. The results mostly provide reliable information on the lunar regolith layer structure and local details with high resolution. This letter presents a further research strategy for lunar probe and deep-space detection with LPR.
Autors: Jing Li;Zhaofa Zeng;Cai Liu;Nan Huai;Kun Wang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 1953 - 1957
Publisher: IEEE
 
» A Study on Optimal BAR in Array Head Reading
Abstract:
Two-dimensional magnetic recording (TDMR), which combines shingled magnetic recording (SMR) with 2-D signal processing attracts attention from the hard disk drive industry. SMR is a magnetic recording system in order to increase the track density by writing tracks without the guard band. Therefore, the influences of writing and reading intertrack interferences (ITIs) deteriorate the quality of reproducing waveforms. Additionally, degradation of track due to overwriting and crosstalk from the adjacent tracks due to the width of reader sensitivity. The equalization using 2-D finite impulse response filter for the waveforms from three adjacent tracks is proposed as a method to reduce the influence of reading ITIs. In this paper, we evaluate the bit aspect ratio (BAR) in TDMR read/write channel under a specification of 4 Tb/in2 using bit error rate of the low-density parity-check (LDPC) coding and iterative decoding system obtained by computer simulation. The results show that the suitable BAR in array head reading is 2.0.
Autors: T. Kondoh;Y. Nakamura;M. Nishikawa;H. Osawa;Y. Okamoto;Y. Kanai;H. Muraoka;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» A Study on Relationship Between Recording Pattern and Decoding Reliability in SMR
Abstract:
The shingled magnetic recording (SMR) system is influenced by not only jitter-like medium noise from adjacent bits in the down-track direction but also intertrack interference (ITI) from the adjacent tracks. In this paper, we investigate the relationship between the recording pattern and the decoding reliability by classifying the log-likelihood ratio at the a posteriori probability decoder output according to the recording patterns under an SMR R–W channel specification of 4 Tb/in2 by computer simulation. The result shows that the decoding reliability for the recording pattern “010” heavily affected by transition jitter is the lowest and little improved even if the influence of ITI is mitigated by a 2-D finite-impulse response filter.
Autors: R. Suzutou;Y. Nakamura;M. Nishikawa;H. Osawa;Y. Okamoto;Y. Kanai;H. Muraoka;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» A Study on the Multi-Channel TMS Device
Abstract:
Transcranial magnetic stimulation (TMS) is a painless, non-invasive brain nerve stimulation technique, which has been a common diagnosis and treatment method for psychiatry and neurology in recent years. Compared with traditional single-channel magnetic stimulation coil, multi-channel coil array can achieve multi-point synchronous stimulation, scanning stimulation, and flexible switching of various stimulation patterns. Therefore, it has a great development prospect. However, the multi-channel TMS device is still in experimental stage due to the complexity of the drive circuit and the electromagnetic coupling between the coils. Aiming at these two difficulties, this paper developed a novel multi-channel TMS device. By using two closely linked coils with opposite rounded direction to replace one coil, the complexity of the drive circuit can be greatly reduced. Then, the experiment was taken to study the effect of electromagnetic coupling on pulse current in different stimulation patterns. The results show that the coupling coefficient between the adjacent coils limits the minimum amplitude ratio of the auxiliary current to main current. Therefore, the measure of reducing the coupling coefficient was studied in detail. Adding a 6.5 cm-high and 1 mm-thick copper plate in the middle of the adjacent coils was proven to be effective by simulation and experiment.
Autors: Jiangtao Li;Hui Cao;Zheng Zhao;Minjun Zheng;Yuhao Liu;Jiaxin He;Yi Sun;Ziyuan Ren;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» A Switched-Capacitor-Controlled Digital-Current Modulated Class-E Transmitter
Abstract:
An envelope elimination and restoration transmitter that comprises a class-E power amplifier (PA) and a digitally controlled current digital-to-analog converter (DAC) modulator are presented. A switched-capacitor DAC is designed to control an open-loop transconductor that operates as a current modulator, modulating the amplitude of the current supplied to a class-E PA. Such a topology allows for increased filtering of the quantization noise that is problematic in most digital PAs (DPA). The system measurements yield a peak output power and system efficiency (SE) of 22.5 dBm and 23.6%, respectively. When applying a local thermal equilibrium signal, the measured error vector magnitude is 3.72% and the adjacent channel leakage ratio is −30.2 dBc, while outputting 18.1 dBm at 10.6% SE.
Autors: Wen Yuan;Jeffrey S. Walling;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3218 - 3226
Publisher: IEEE
 
» A Systematic Approach for Variable Selection With Random Forests: Achieving Stable Variable Importance Values
Abstract:
Random Forests variable importance measures are often used to rank variables by their relevance to a classification problem and subsequently reduce the number of model inputs in high-dimensional data sets, thus increasing computational efficiency. However, as a result of the way that training data and predictor variables are randomly selected for use in constructing each tree and splitting each node, it is also well known that if too few trees are generated, variable importance rankings tend to differ between model runs. In this letter, we characterize the effect of the number of trees (ntree) and class separability on the stability of variable importance rankings and develop a systematic approach to define the number of model runs and/or trees required to achieve stability in variable importance measures. Results demonstrate that both a large ntree for a single model run, or averaged values across multiple model runs with fewer trees, are sufficient for achieving stable mean importance values. While the latter is far more computationally efficient, both the methods tend to lead to the same ranking of variables. Moreover, the optimal number of model runs differs depending on the separability of classes. Recommendations are made to users regarding how to determine the number of model runs and/or trees that are required to achieve stable variable importance rankings.
Autors: Amir Behnamian;Koreen Millard;Sarah N. Banks;Lori White;Murray Richardson;Jon Pasher;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 1988 - 1992
Publisher: IEEE
 
» A Temperature Compensated Triple-Path PLL With $K_{mathrm {VCO}}$ Non-Linearity Desensitization Capable of Operating at 77 K
Abstract:
A novel triple-path PLL (TPPLL) is presented to compensate the VCO frequency drift caused by the large temperature variations meanwhile maintaining a stable bandwidth and good jitter performance. The proposed PLL architecture splits the VCO tuning loop into three paths as the proportional, the integral, and the temperature compensation (TC) path, respectively. The feed-forward TC path with a large VCO gain but a small bandwidth is adopted to realize the compensation for the VCO frequency temperature drift in a closed-loop manner without affecting the high-frequency performance of the VCO. The fixed control voltage on the proportional path and limited control-voltage variation on the integral path desensitize the VCO gain () non-linearity and stabilizes the loop bandwidth over large temperature range. The small VCO gain on the proportional and integral paths contributes to low phase noise and spurs. In addition, the different gain settings for the separate proportional and integral paths work as a capacitor multiplier, leading to saving on the silicon area of the loop filter. A prototype TPPLL at 2.56 GHz using a 65-nm CMOS process has been implemented and measured. The core circuits occupy an area of 0.08 mm2, and consume 8.5 mW. The silicon measurement results show that this PLL can continuously work (without calibration) when the temperature changes from 300 K down to 77 K, and has a frequency drift reduction by 99%, while keeping good jitter performance across the entire temperature range.
Autors: Tianwei Liu;Xiaoran Wang;Rui Wang;Guoying Wu;Tao Zhang;Ping Gui;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Nov 2017, volume: 64, issue:11, pages: 2835 - 2843
Publisher: IEEE
 
» A Thin-Film, a-IGZO, 128b SRAM and LPROM Matrix With Integrated Periphery on Flexible Foil
Abstract:
A fast, 128-b implementation of both SRAM and LPROM with integrated periphery in a thin-film amorphous indium–gallium–zinc oxide technology is reported. The SRAM block can be read in 265 /byte and written in 110 /byte, consumes 12.3 mW, and has an area of 11.9 mm2. Furthermore, after power down, an SRAM memory state retention time of 83 s is shown. The LPROM can be read in 40 /b, consumes 4.50 mW, and has an area of 3.75 mm2. The SRAM enables fast volatile RAM memory for thin-film microprocessors, while the LPROM can be used to store the identification code for state-of-the-art thin-film RFID tags.
Autors: Florian De Roose;Kris Myny;Marc Ameys;Jan-Laurens P. J. van der Steen;Joris Maas;Joris de Riet;Jan Genoe;Wim Dehaene;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Nov 2017, volume: 52, issue:11, pages: 3095 - 3103
Publisher: IEEE
 
» A Third-Order MASH $Sigma Delta $ Modulator Using Passive Integrators
Abstract:
This paper presents a MASH using only passive integrators and simple differential pairs as low-gain blocks. Instead of high-gain power hungry op-amps it uses more processing gain from the comparator (1-bit quantizer) as a part of the loop gain. The proposed approach allows the design of a continuous-time, 2–1 MASH in a 65-nm CMOS technology occupying an area of just 0.027 mm2. Measurement results show that the modulator achieves a peak SNR/SNDR of 76/72.2 dB and a DR of 77 dB for an input signal bandwidth of 10 MHz, while dissipating 1.57 mW with 1 V supply. The proposed achieves a Walden figures of merit (FoM) of 23.6 fJ/level and a Schreier FOM of 170 dB.
Autors: Błażej Nowacki;Nuno Paulino;João Goes;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Nov 2017, volume: 64, issue:11, pages: 2871 - 2883
Publisher: IEEE
 
» A Truncated Prediction Framework for Streaming Over Erasure Channels
Abstract:
We propose a new coding technique for sequential transmission of a stream of Gauss–Markov sources over erasure channels under a zero decoding delay constraint. Our proposed scheme is a combination (hybrid) of predictive coding with truncated memory, and quantization-and-binning. We study the optimality of our proposed scheme using an information theoretic model. In our setup, the encoder observes a stream of source vectors that are spatially independent and identically distributed (i.i.d.) and temporally sampled from a first-order stationary Gauss–Markov process. The channel introduces an erasure burst of a certain maximum length , starting at an arbitrary time, not known to the transmitter. The reconstruction of each source vector at the destination must be with zero delay and satisfy a quadratic distortion constraint with an average distortion of . The decoder is not required to reconstruct those source vectors that belong to the period spanning the erasure burst and a recovery window of length following it. We study the minimum compression rate in this setup. As our main result, we establish upper and lower bounds on the compression rate. The upper bound (achievability) is based on our hybrid scheme. It achieves significant gains over baseline schemes such as (leaky) predictive coding, memoryless binning, a separation-based scheme, and a group of pictures-based scheme. The lower bound is established by observing connection to a network source coding problem. The bounds simplify in the high resolution regime, where we provide explicit expressions whenever possible, and identify conditions when the proposed scheme is cl- se to optimal. We finally discuss the interplay between the parameters of our burst erasure channel and the statistical channel models and explain how the bounds in the former model can be used to derive insights into the simulation results involving the latter. In particular, our proposed scheme outperforms the baseline schemes over the i.i.d. erasure channel and the Gilbert–Elliott channel, and achieves performance close to a lower bound in some regimes.
Autors: Farrokh Etezadi;Ashish Khisti;Jun Chen;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 7322 - 7351
Publisher: IEEE
 
» A Tunable 5–7 GHz Distributed Active Quasi-Circulator With 18-dBm Output Power in CMOS SOI
Abstract:
Circulators and quasi-circulators (QCs) have a tradeoff between maximum isolation and bandwidth. We present a tunable distributed active circuit to achieve high isolation over a wide frequency range. The reported QC provides more than 40-dB suppression between transmit (TX) output signal at the antenna and TX leakage into the receive (RX) port over a tuning range of 5.3–7.3 GHz in small-signal operation. Large-signal TX-RX suppression is optimized across power level. The TX output achieves peak power of 18 dBm and 12% power-added efficiency at 6.3 GHz. The QC is designed in a high-resistivity 45-nm CMOS silicon-on-insulator process and occupies an area of .
Autors: Kelvin Fang;James F. Buckwalter;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Nov 2017, volume: 27, issue:11, pages: 998 - 1000
Publisher: IEEE
 
» A Unified Approach for Modeling Fading Channels Using Infinitely Divisible Distributions
Abstract:
This paper proposes to unify fading distributions by modeling the instantaneous SNR as an infinitely divisible random variable, which is a known class of random variables from the probability theory literature. A random variable is said to be infinitely divisible if it can be written as a sum of independent and identically distributed random variables for each . The proposed unification subsumes several classes of multipath and shadowing fading distributions previously proposed in the wireless communication literature. We show that infinitely divisible random variables have many useful mathematical properties that are applied in the performance analysis of wireless systems. Specific applications include diversity analysis and partial ordering of fading distributions.
Autors: Adithya Rajan;Cihan Tepedelenlioğlu;Ruochen Zeng;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10194 - 10206
Publisher: IEEE
 
» A Variance Distribution Model of Surface EMG Signals Based on Inverse Gamma Distribution
Abstract:
Objective: This paper describes the formulation of a surface electromyogram (EMG) model capable of representing the variance distribution of EMG signals. Methods: In the model, EMG signals are handled based on a Gaussian white noise process with a mean of zero for each variance value. EMG signal variance is taken as a random variable that follows inverse gamma distribution, allowing the representation of noise superimposed onto this variance. Variance distribution estimation based on marginal likelihood maximization is also outlined in this paper. The procedure can be approximated using rectified and smoothed EMG signals, thereby allowing the determination of distribution parameters in real time at low computational cost. Results: A simulation experiment was performed to evaluate the accuracy of distribution estimation using artificially generated EMG signals, with results demonstrating that the proposed model's accuracy is higher than that of maximum-likelihood-based estimation. Analysis of variance distribution using real EMG data also suggested a relationship between variance distribution and signal-dependent noise. Conclusion: The study reported here was conducted to examine the performance of a proposed surface EMG model capable of representing variance distribution and a related distribution parameter estimation method. Experiments using artificial and real EMG data demonstrated the validity of the model. Significance: Variance distribution estimated using the proposed model exhibits potential in the estimation of muscle force.
Autors: Hideaki Hayashi;Akira Furui;Yuichi Kurita;Toshio Tsuji;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Nov 2017, volume: 64, issue:11, pages: 2672 - 2681
Publisher: IEEE
 
» A Vector Flow Imaging Method for Portable Ultrasound Using Synthetic Aperture Sequential Beamforming
Abstract:
This paper presents a vector flow imaging method for the integration of quantitative blood flow imaging in portable ultrasound systems. The method combines directional transverse oscillation (TO) and synthetic aperture sequential beamforming to yield continuous velocity estimation in the whole imaging region. Six focused emissions are used to create a high-resolution image (HRI), and a dual-stage beamforming approach is used to lower the data throughput between the probe and the processing unit. The transmit/receive focal points are laterally separated to obtain a TO in the HRI that allows for the velocity estimation along the lateral and axial directions using a phase-shift estimator. The performance of the method was investigated with constant flow measurements in a flow rig system using the SARUS scanner and a 4.1-MHz linear array. A sequence was designed with interleaved B-mode and flow emissions to obtain continuous data acquisition. A parametric study was carried out to evaluate the effect of critical parameters. The vessel was placed at depths from 20 to 40 mm, with beam-to-flow angles of 65°, 75°, and 90°. For the lateral velocities at 20 mm, a bias between −5% and −6.2% was obtained, and the standard deviation (SD) was between 6% and 9.6%. The axial bias was lower than 1% with an SD around 2%. The mean estimated angles were 66.70° ± 2.86°, 72.65° ± 2.48°, and 89.13° ± 0.79° for the three cases. A proof-of-concept demonstration of the real-time processing and wireless transmission was tested in a commercial tablet obtaining a frame rate of 27 frames/s and a data rate of 14 MB/s. An in vivo measurement of a common carotid artery of a healthy volunteer was finally performed to show the potential of the method in a realistic setting. The relative SD averaged over a cardiac cycle was 4.33%.
Autors: Tommaso Di Ianni;Carlos Armando Villagómez Hoyos;Caroline Ewertsen;Thomas Kim Kjeldsen;Jesper Mosegaard;Michael Bachmann Nielsen;Jørgen Arendt Jensen;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Nov 2017, volume: 64, issue:11, pages: 1655 - 1665
Publisher: IEEE
 
» A Very Fast Trace-Driven Simulation Platform for Chip-Multiprocessors Architectural Explorations
Abstract:
Simulation is the main tool for computer architects and parallel application developers for developing new architectures and parallel algorithms on many-core machines. Simulating a many-core architecture represent a challenge to software simulators even with parallelization of these SW on multi-cores. Field Programmable Gate Arrays offer an excellent implementation platform due to inherent parallelism. Existing FPGA-based simulators however, are mostly execution-driven which consumes too many FPGA resources. Hence, they still trade-off accuracy with simulation speed as SW simulators do. In this work, an application-level trace-driven FPGA-based many-core simulator is presented. A parameterized Verilog template was developed that can generate any number of simulator tiles. The input trace has an architecturally agnostic format that is directly interpreted by the FPGA-based timing model to re-construct the execution events of the original application with accurate timing. This allows fitting a large number of simulation tiles on a single FPGA without sacrificing simulation speed or accuracy. Experimental results show that the simulator's average accuracy is ∼14 percent with simulation speeds ranging from 100’s of MIPs to over 2,200 MIPS for a 16-core target architecture. Hence, with accuracy similar to SW simulators, its speed is higher than all other FPGA-based simulators.
Autors: Muhammad E. S. Elrabaa;Ayman Hroub;Muhamed F. Mudawar;Amran Al-Aghbari;Mohammed Al-Asli;Ahmad Khayyat;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Nov 2017, volume: 28, issue:11, pages: 3033 - 3045
Publisher: IEEE
 
» A Vessel Detection Method Using Compact-Array HF Radar
Abstract:
A compact-array high-frequency surface wave radar equipped with two crossed-loop/monopole receiving antennas has been established for vessel detection. Using two compact antennas of the same design, this system can obtain two extremely similar sets of radar range-Doppler spectra over the same period. To detect vessel targets efficiently, the spectra of two antennas are enhanced by performing a principle component analysis. A wavelet-based approach is then applied to suppress clutter and reduce noise. The signal-to-noise ratios and signal-to-clutter ratios of the echoes are thus improved. Finally, an adaptive threshold is used to extract targets. The real radar data detection results are compared with Automatic Identification System data as well as those from the conventional ordered-statistic constant false alarm rate method. The feasibility and the validity of method proposed here are thus demonstrated.
Autors: Bo Lu;Biyang Wen;Yingwei Tian;Ruokun Wang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 2017 - 2021
Publisher: IEEE
 
» A Voltage-Based Approach for Fault Detection and Separation in Permanent Magnet Synchronous Machines
Abstract:
Different faults in permanent magnet synchronous machines (PMSMs) cause various and independent changes to the machine magnetic flux distribution, which affect the machine parameters and performance. These changes are reflected in the machine flux linkages and can be estimated from the machine voltages. In this paper, we continue the work of Haddad et al., where a method was proposed to detect and separate three types of faults in PMSMs: 1) static eccentricity; 2) demagnetization; and 3) turn-to-turn short circuit. The method proposed here is based on using the change in the commanded - and -axis voltages, while the machine is operating at steady state, for fault detection and separation. Simulation tests using finite element analysis (FEA) software (MAGSOFT-Flux2D) were performed under healthy and the tested fault conditions on a three-phase ten-pole fractional-slot concentrated-winding PMSM. An analytical method is proposed to estimate the commanded voltages at any operating condition, and a classification algorithm is implemented for fault detection and classification. Experimental tests were carried out and compared with FEA. The effects of the variation in the operating speed and temperature were simulated and tested to validate the detection method under different operating conditions.
Autors: Reemon Z. Haddad;Cristian A. Lopez;Shanelle N. Foster;Elias G. Strangas;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5305 - 5314
Publisher: IEEE
 
» A Wavelet-Based AFM Fast Imaging Method With Self-Tuning Scanning Frequency
Abstract:
Due to its numerous advantages, atomic force microscopy (AFM) has been widely utilized in various fields, such as nanotechnology, nanomanipulation, bioscience, etc. However, when considering the increasing requirements from different applications, low scanning speed is one of the most challenging drawbacks which prevents further applications of an AFM system. Based on this observation, this paper proposes a novel wavelet-based AFM fast imaging method with an intelligent adjustment mechanism for scanning frequency over different parts of detected samples, which is especially efficient when scanning biological samples with sparse features. More specifically, a sample is first skipped through quickly with forward scan, during which wavelet analysis is implemented for the collected data to distinguish interesting areas from uninteresting ones, based on which, the sample is then reversely scanned with varying frequencies to obtain trusty information to generate an accurate image for its surface. That is, the proposed fast AFM imaging method carefully scans the identified interesting areas at comparatively low frequency, while skipping through the uninteresting ones quickly with much higher speed, so as to reduce scanning time and simultaneously enhance imaging performance. Performance analysis demonstrates that, due to its unique ability of intelligent tuning for scanning speeds, the designed wavelet-based AFM scanning method maximally increases the imaging speed by ten times. In addition, both simulation and experimental results also verify the good performance of the proposed method. The designed imaging method is finally utilized to scan some biological samples, with collected results further exhibiting its promising prospect.
Autors: Yinan Wu;Yongchun Fang;Xiao Ren;Han Lu;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Nov 2017, volume: 16, issue:6, pages: 1088 - 1098
Publisher: IEEE
 
» A Weighted Combining Algorithm for Spatial Multiplexing MIMO DF Relaying Systems
Abstract:
Jointly detecting the signals from the source and relay in a spatial multiplexing (SM) multiple-input multiple-output (MIMO) relaying system improves the transmit reliability significantly. However, the existing joint detection schemes for SM MIMO relaying systems, which achieve full diversity, such as the near maximum likelihood (ML) decoder, suffer from high complexity. In this paper, we propose a weighted combining (WC) algorithm, which is applied before the detector in the SM MIMO decode-and-forward relaying system. The proposed algorithm merges the received signal vectors from the source and relay into a combined signal without expanding their dimension, and formulates an equivalent MIMO channel matrix for the combined signal, resulting in a lower complexity for the subsequent detection. We analyze the performance of the proposed WC algorithm with ML detection in terms of the diversity order and computational complexity. An approximate upper bound on the symbol error probability (SEP) for the proposed algorithm is also derived. Simulation results show that in symmetric networks, the proposed WC algorithm achieves substantially lower complexity, while maintaining an SEP performance similar to that of the benchmark NML decoder. The consistency of the derived upper bound on the SEP is also verified by simulations.
Autors: Kangli Zhang;Jian Wang;Jiaxin Yang;Benoit Champagne;Fanglin Gu;Jibo Wei;
Appeared in: IEEE Transactions on Communications
Publication date: Nov 2017, volume: 65, issue:11, pages: 4751 - 4764
Publisher: IEEE
 
» A Wideband All-Digital CMOS RF Transmitter on HDI Interposers With High Power and Efficiency
Abstract:
This paper demonstrates a wideband CMOS all-digital polar transmitter with flip-chip connection to three high-density-interconnection PCB interposers. The interposers are designed to extract power from a CMOS open-drain inverse Class-D power amplifier core. For a wide frequency range from 0.7 to 3.5 GHz, continuous-wave output power higher than 25.5 dBm and drain efficiency (DE) above 40% are demonstrated. The low-band package achieves a peak power of 29.2 dBm at 1.1 GHz with DE of 60%, the mid-band package outputs 28.8 dBm at 1.5 GHz with DE of 56%, and the high-band package generates 26 dBm at 3 GHz with DE of 49%. The amplitude modulation (AM) is achieved by digitally modulating the switch conductance of the inverse Class-D core, and the on-chip phase modulation is achieved by digitally weighing the in-phase and quadrature bias currents in the IQ mixer. Detailed modulation tests, involving 64 quadrature amplitude modulation (QAM) and 20-MHz WLAN and LTE signals, exhibit excellent power and efficiency at 0.6, 1.2, 1.8, 2.4, 3, and 3.6 GHz. The associated specifications on spectral masks and error vector magnitudes are satisfied.
Autors: Nai-Chung Kuo;Bonjern Yang;Angie Wang;Lingkai Kong;Charles Wu;Vason P. Srini;Elad Alon;Borivoje Nikolić;Ali M. Niknejad;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Nov 2017, volume: 65, issue:11, pages: 4724 - 4743
Publisher: IEEE
 
» A Withered Tree Comes to Life Again: Enabling In-Network Caching in the Traditional IP Network
Abstract:
This article presents our work proposing in-network caching in IP-based networks by adding a content identifier into a newly defined IPv6 extension header, where the new architecture is named CAIP. CAIP abandons the complicated name-based forwarding table in ICN, and instead integrates IP routing lookup with cache index lookup, which is compatible with the IP network and also inherits the proven advantages of ICN. Cache index exchanging and cooperative caching are implemented between one-hop CAIP enabled neighboring routers, which is simple but efficient. Moreover, for per-chunk caching, as an extension, bitmap is introduced to merge multiple request packets into one. Performance analysis shows that CAIP gains significant performance improvement in terms of access delay and traffic load.
Autors: Kaiping Xue;Tingting Hu;Xiang Zhang;Peilin Hong;David S.L. Wei;Feng Wu;
Appeared in: IEEE Communications Magazine
Publication date: Nov 2017, volume: 55, issue:11, pages: 186 - 193
Publisher: IEEE
 
» Absorptive Frequency-Selective Reflection and Transmission Structures
Abstract:
Tailoring methodology is proposed in this communication to achieve an arbitrary frequency response within a wide absorption band. An ultrawideband (UWB) absorber utilizing multiple resonances in the unit cell of 3-D frequency-selective structure is utilized as the textile for the proposed designs. Two types are proposed: one is absorptive frequency-selective reflection structure (AFSR) and the other is absorptive frequency-selective transmission structure (AFST). These structures have reflection/transmission band within a wide absorption band. Two prototypes are designed, fabricated, and measured to validate the proposed methodology. The first one is an UWB absorber with 155.7% absorption bandwidth from 1.8 to 14.4 GHz with structure’s thickness of at the lowest absorption frequency. The second one is an AFST with wide absorption bands at both sides of its transmission window. It exhibits 54% and 76% for the lower and upper absorption bands, respectively, with 1 dB insertion loss in the transmission window. A good agreement is achieved between simulation and measured results.
Autors: Ahmed Abdelmottaleb Omar;Zhongxiang Shen;Hao Huang;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6173 - 6178
Publisher: IEEE
 
» Accelerating Decision Tree Based Traffic Classification on FPGA and Multicore Platforms
Abstract:
Machine learning (ML) algorithms have been shown to be effective in classifying a broad range of applications in the Internet traffic. In this paper, we propose algorithms and architectures to realize online traffic classification using flow level features. First, we develop a traffic classifier based on C4.5 decision tree algorithm and Entropy-MDL (Minimum Description Length) discretization algorithm. It achieves an overall accuracy of 97.92 percent for classifying eight major applications. Next we propose approaches to accelerate the classifier on FPGA (Field Programmable Gate Array) and multicore platforms. We optimize the original classifier by merging it with discretization. Our implementation of this optimized decision tree achieves 7500+ Million Classifications Per Second (MCPS) on a state-of-the-art FPGA platform and 75-150 MCPS on two state-of-the-art multicore platforms. We also propose a divide and conquer approach to handle imbalanced decision trees. Our implementation of the divide-and-conquer approach achieves 10,000+ MCPS on a state-of-the-art FPGA platform and 130-340 MCPS on two state-of-the-art multicore platforms. We conduct extensive experiments on both platforms for various application scenarios to compare the two approaches.
Autors: Da Tong;Yun Rock Qu;Viktor K. Prasanna;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Nov 2017, volume: 28, issue:11, pages: 3046 - 3059
Publisher: IEEE
 
» Accessible Software Verification with Dafny
Abstract:
Dafny is a formal-verification system that takes a language-based approach. Its programming language includes the necessary specification and proof facilities. The idea is to provide developers with an immersive experience that feels like programming but encourages thinking about program correctness every step of the way.
Autors: K. Rustan M. Leino;
Appeared in: IEEE Software
Publication date: Nov 2017, volume: 34, issue:6, pages: 94 - 97
Publisher: IEEE
 
» Accumulate Repeat Accumulate Check Accumulate Codes
Abstract:
In this paper, a novel accumulate-repeat-accumulate-check-accumulate (ARACA) code is proposed as a subclass of protograph-based low-density parity-check (LDPC) codes. The key feature of the proposed ARACA code is represented by the outer connection doping in the protograph. This feature can provide the linear minimum distance growth (LMDG) property at a good iterative decoding threshold while maintaining an efficient encoder structure. The effect of the outer connection doping on the typical minimum distance, the iterative decoding threshold, and the LMDG property is discussed and analyzed by comparing case examples and using the asymptotic protograph ensemble weight enumerator. Some good ARACA code protographs are provided for a wide range of code rates. In addition, an efficient and universal encoding procedure and the corresponding encoder structure are provided for them. The performance of the proposed ARACA code is evaluated and compared with well-known good LDPC codes. The simulation results confirm the superiority of the proposed ARACA codes in terms of encoding complexity and frame error rate performance, especially at low-rates in an ultra-reliable regime.
Autors: Ki Jun Jeon;Kwang Soon Kim;
Appeared in: IEEE Transactions on Communications
Publication date: Nov 2017, volume: 65, issue:11, pages: 4585 - 4599
Publisher: IEEE
 
» Accurate De-Embedding and Measurement of Spin-Torque Oscillators
Abstract:
We present a method for accurately de-embedding the electrical effects of the bias and measurement electrode structure used for spin-torque oscillator (STO) measurements. We propose a simple, but very accurate, method that requires only one additional test structure per STO wafer. We show that the effects of the electrode structure, including phase shift over frequency and insertion loss, can be removed, providing an accurate measurement of the true STO parameters. Our method is verified using 24 STOs across four different wafers each containing 140 STOs.
Autors: M. Abbasi;B. Wang;S. Tamaru;H. Kubota;A. Fukushima;D. S. Ricketts;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Accurate Floating-Point Argument Calculation for Sine-Fitting Algorithms
Abstract:
In this paper, accurate argument calculation for sine-fitting algorithms is investigated, assuming floating-point (FP) arithmetic. An easy-to-implement incremental calculation technique is suggested. In order to decrease error propagation, the algorithm is complemented with an advanced summation technique. Theoretical and numerical analyses on computational demand are performed to highlight that incremental argument calculation outperforms the method proposed in former research. Furthermore, an algorithm is implemented to mitigate the effect of imprecise representation of frequency on FP arithmetic. Monte Carlo analyses are carried out to demonstrate the accuracy of the suggested algorithms. Results show that phase information can be evaluated precisely even with single-precision FP arithmetic, applying incremental argument calculation. By this means, the cost of equipment that is needed to perform sine fitting can be reduced significantly. Finally, possible application areas are shown to demonstrate the applicability of the suggested solutions in the state-of-art measurement procedures.
Autors: Balázs Renczes;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 2988 - 2996
Publisher: IEEE
 
» Achievable Rates of Full-Duplex Massive MIMO Relay Systems Over Rician Fading Channels
Abstract:
We analytically study the achievable rates of full-duplex massive multiple-input multiple-output (MIMO) relay systems over Rician fading channels. The decode-and-forward protocol is adopted at the relay station, where the channel state information (CSI) is assumed to be imperfect. We demonstrate that the system bottleneck, self-interference (SI), can be significantly canceled by zero-forcing (ZF) processing at the relay station, which is equipped with massive receive and transmit arrays. Because no active SI cancellation is deployed at the relay station, there is no need for SI channel estimation. We derive an approximate closed-form achievable rate expression for ZF processing with statistical CSI. When the number of antennas of the transmit and receive arrays at the relay station is sufficiently large, the transmit powers of each source and the relay station can be significantly scaled down proportionally to the number of antennas. Since Rayleigh fading is a special case of Rician fading, the results in this paper hold for Rayleigh fading channels. The theoretical analysis is verified by the numerical results.
Autors: Siyuan Wang;Yi Liu;Wei Zhang;Hailin Zhang;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 9825 - 9837
Publisher: IEEE
 
» Achieving Content-Oriented Anonymity with CRISP
Abstract:
As a popular realization of Information-Centric Network (ICN), Named Data Networking (NDN) greatly improves the efficiency of Internet content-distribution. A feature of NDN is that it improves privacy, as no addresses are needed for either the content consumer or publisher. However, NDN packets contain content names, and hence a well-motivated adversary can still deduce what content the user is requesting once it can link the packets and users. How to provide privacy in NDN, given its unique data retrieval mode, is an open problem. In this paper, we explore a specific content-oriented anonymity model called content-user unlinkability, which breaks the relationship between the content and the requesting user. We argue that achieving content-user unlinkability efficiently is a non-trivial task, since existing tunnel-based approaches will largely dismiss content caching of NDN, resulting in large content retrieval delay. To this end, we propose CRISP, namely Cooperative Random IntereSt P ropagation. In CRISP, routers cooperate to form full-meshed groups, within which content requests are randomly propagated before they are forwarded to content producers. We show CRISP can achieve probable content-user unlinkability with probabilistic models. Extensive simulations demonstrate that CRISP outperforms existing solutions including ANDANA and Crowds, in terms of both content retrieval latency and data throughput.
Autors: Peng Zhang;Qi Li;Patrick P. C. Lee;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Nov 2017, volume: 14, issue:6, pages: 578 - 590
Publisher: IEEE
 
» Achieving Full Secure Degrees-of-Freedom for the MISO Wiretap Channel With an Unknown Eavesdropper
Abstract:
In this paper, we study the achievable secure degrees-of-freedom (sdof) for the multiple-input single-output (MISO) wiretap channel with an unknown eavesdropper. It is assumed that the eavesdropper’s (Eve’s) channel state information (CSI) is unknown to the transmitter (Alice) and legitimate receiver (Bob). Recent studies have shown that the achievable sdof in the sense of strong secrecy is zero when Eve’s number of antennas is equal to or more than Bob’s number of antennas, which is the scenario considered in this paper. To this end, we propose a novel precoding technique and a coding strategy that together achieve full sdof in the sense of strong secrecy without knowing Eve’s CSI and without using artificial noise. The proposed precoding method uses the CSI of the Alice-Bob channel in a nonlinear fashion, which makes the transmitted symbols undecodable at Eve. The proposed coding scheme is based on the channel resolvability concept and ensures strong secrecy. Achieving full sdof with an unknown Eve’s CSI is significant, because it is contrary to what is believed about the achievable sdof for the MISO wiretap channel in the sense of strong secrecy. We also show that the proposed scheme achieves near Alice-Bob’s channel capacity in the sense of strong secrecy with a probability approaching one at finite signal-to-noise ratio.
Autors: Mohaned Chraiti;Ali Ghrayeb;Chadi Assi;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Nov 2017, volume: 16, issue:11, pages: 7066 - 7079
Publisher: IEEE
 
» Achieving High Availability in Heterogeneous Cellular Networks via Spectrum Aggregation
Abstract:
The exponential growth in data traffic and dramatic capacity demand in fifth generation (5G) have inspired the move from traditional single-tier cellular networks toward heterogeneous cellular networks (HCNs). To face the coming trend in 5G, the high availability requirement in new applications needs to be satisfied to achieve low latency service. Usually, these applications require an availability of six nines or even higher. In this paper, we present a tractable multitier multiband availability model for spectrum aggregation-based HCNs. We first derive a closed-form expression for the availability of spectrum aggregation-based HCNs using the signal-to-interference-plus-noise model. By doing so, we formulate two optimization problems, one is to maximize the average availability, and the other one is to minimize the average power consumption. These two optimization problems are both nonconvex problems, which are challenging to solve. To cope with them, we propose to apply genetic algorithm for the joint user equipment (UE) association, subcarrier assignment, and power allocation problem. Our results show that the average availability in spectrum aggregation-based HCNs improves with decreasing number of UEs, as well as increasing power budget ratio. We also show that increasing the maximum number of aggregated subcarriers decreases the average power consumption, but cannot guarantee the substantial improvement of average availability.
Autors: Jie Jia;Yansha Deng;Jian Chen;Abdol Hamid Aghvami;Arumugam Nallanathan;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10156 - 10169
Publisher: IEEE
 
» Achieving Theoretical Limit of SFDR in Pipelined ADCs
Abstract:
In pipelined analog-to-digital converters (ADCs), the spurious free dynamic range (SFDR) and signal-to-noise ratio depend strongly on the precision with which the interstage gain and capacitor mismatch terms are estimated using digital calibration techniques. This paper introduces a dithering-based calibration technique, which facilitates accurate estimation of the interstage gain and capacitor mismatch term with minimal hardware overhead, thus realizing pipelined ADCs that achieve the theoretical maximum SFDR. The proposed technique is validated both at system level using MATLAB and then at circuit level. A prototype 12-bit pipelined ADC operating at 500 MHz was designed in 55-nm global foundry LP-CMOS process. The prototype 12-bit ADC realized with op amp that have open-loop gains as low as 54 dB, but linearity ≈100 dB achieves an SFDR of 100.13 dB when calibrated using the proposed technique.
Autors: Vineeth Sarma;Chithira Ravi;Bibhu Datta Sahoo;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3175 - 3185
Publisher: IEEE
 
» Acoustic Resonance Detection Using Statistical Methods of Voltage Envelope Characterization in Metal Halide Lamps
Abstract:
Acoustic resonance (AR) phenomenon occurs in metal halide lamps and can cause light flicker, lamp arc bending and rotation, lamp extinction, and in the worst case, arc tube explosion. This study takes place in the context of developing electronic ballasts with robust AR detection and avoidance mechanisms. To this end, a lock-in amplifier is used to measure and characterize lamp voltage root mean square (rms) short-term fluctuations. Statistical criteria based on the standard deviation of this rms value are proposed to assess AR presence and classify its severity. A set of metal halide lamps from different manufacturers and with different powers were tested. The average electrical power and AR level are controlled by adjusting the lamp operating frequency of high-frequency electronic ballast. The proposed criteria enable classifying healthy (without AR) and faulty (with AR) cases based upon either a two-dimensional plane or a boxplot. Regardless of lamp operating power, the results from this study show that the voltage rms variations and the defined criteria are significantly correlated with AR level.
Autors: Fang Lei;Pascal Dupuis;Olivier Durrieu;Georges Zissis;Pascal Maussion;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5988 - 5996
Publisher: IEEE
 
» Active Damping of Ultrafast Mechanical Switches for Hybrid AC and DC Circuit Breakers
Abstract:
An active damping method for Thomson coil actuated ultrafast mechanical switches is proposed, including its control. Ultrafast mechanical switches are crucial for both dc and ac circuit breakers that require fast-acting current-limiting capabilities. However, fast motion means high velocity at the end of travel resulting in over-travel, bounce, fatigue, and other undesirable effects. The active damping proposed in this paper not only avoids such issues but actually enables faster travel by removing limitations that would otherwise be necessary. This active damping mechanism is applicable in particular to medium- and high-voltage circuit breakers, but can be extended to actuators in general. A 15 kV/630 A/1 ms mechanical switch designed to enable the fast protection of medium voltage dc circuits is used as a testbed for the concept. The switch is based on the principle of repulsion forces (Thomson coil actuator). By energizing a second coil, higher opening speeds can be damped, resulting in limited over-travel range of the movable contact. The overall structure is simple and the size of the overall switch is minimized. To validate the concept and to study the timing control for best active damping performance, both finite element modeling and experimental studies have been carried out.
Autors: Chang Peng;Landon Mackey;Iqbal Husain;Alex Q. Huang;Wensong Yu;Bruno Lequesne;Roger Briggs;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5354 - 5364
Publisher: IEEE
 
» Active Disturbance Rejection Control for Uncertain Nonaffine-in-Control Nonlinear Systems
Abstract:
In this technical note, the active disturbance rejection control (ADRC) is generalized to uncertain nonaffine-in-control nonlinear systems. The proposed controller incorporates both an extended state observer (ESO) as well as a dynamic inversion. The ESO is designed to estimate system state and total uncertainty, which includes the uncertain internal dynamics and the external disturbance, and is nonaffine-in-control. Based on the output of the ESO, the dynamic inversion is used to deal with the nonaffine-in-control problem. The proposed control has a multi-time-scale structure, in which the ESO is the fastest time scale; the dynamic inversion is the second; and the considered nonlinear system is the slowest. The practical convergence of the resulting closed-loop system is obtained. An example is presented to illustrate the efficiency of the proposed method.
Autors: Maopeng Ran;Qing Wang;Chaoyang Dong;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5830 - 5836
Publisher: IEEE
 
» Active Eight-Path Filter and LNA With Wide Channel Bandwidth and Center Frequency Tunability
Abstract:
This paper presents a differential eight-path bandpass filter with tunable center frequency and bandwidth. Fully differential Miller compensated Butterworth Gm-C biquads are used to implement the active low-pass filters required in the structure of the eight-path filter. The −3-dB bandwidth of each Gm-C filter can be tuned from 2.5 to 51 MHz by means of six digital bits. The center frequency of the eight-path filter can be tuned from 100 MHz to 2 GHz by varying the frequency of the 12.5% duty cycle clocks applied to the gates of the switches in the filter. A wideband low-noise amplifier (LNA) is designed to precede the eight-path filter and acts as an active single-to-differential converter while providing a moderate voltage gain to compensate for the noise produced by the eight-path filter. The LNA has a noise canceling common-gate common-source with 20 dB of gain and a noise figure (NF) of 1.8 dB. The filter and LNA are designed and fabricated in 180-nm CMOS process. The circuit operates in 100 MHz to 2 GHz frequency range, achieving a voltage gain of 19 dB and a total NF of 3.3 dB. The achieved out-of-band input third-order intercept point of the circuit is +23 dBm, and the power consumption of the filter is approximately 32.3 mW, while the LNA consumes 16.5 mW.
Autors: Baktash Behmanesh;Seyed Mojtaba Atarodi;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Nov 2017, volume: 65, issue:11, pages: 4715 - 4723
Publisher: IEEE
 
» Active-Phase Converter for Operation of Three-Phase Induction Motors on Single-Phase Grid
Abstract:
The operation of a three-phase induction machine on single-phase supply has been an approach used for electromechanical energy conversion in rural communities with limited or no access to the three-phase grid. Such single-phase to three-phase conversion can be achieved by passive and active means. In passive methods, fixed capacitors are used for starting and running the motor. Single-phase to three-phase conversion with reduced switch count is desirable, as this leads to a lower cost. However, it is a challenge to start an induction motor using such a power converter and to maintain balanced three-phase voltage under all loading conditions. It is shown in this work that balanced excitation cannot be achieved under all conditions with variable capacitor emulation method. An active phase-converter configuration and its control that ensures balanced three-phase power supply at the motor terminals under all operating conditions is proposed. Also, this approach has the ability to soft-start the motor. It is shown that this can be done without drawing excessive currents from the power converter or from the single-phase grid. A design methodology is presented for the selection of the autotransformer taps to limit startup transient currents to the desired level, based on the analytical results. Simulation and experimental results are presented that validate the proposed topology and control.
Autors: Anil K. Adapa;Vinod John;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5668 - 5675
Publisher: IEEE
 
» Activity Maximization by Effective Information Diffusion in Social Networks
Abstract:
In a social network, even about the same information the excitement between different users are different. If we want to spread a piece of new information and maximize the expected total amount of excitement, which seed users should we choose? This problem indeed is substantially different from the renowned influence maximization problem and cannot be tackled using the existing approaches. In this paper, motivated by the demand in a few interesting applications, we model the novel problem of activity maximization, and tackle the problem systematically. We first analyze the complexity and the approximability of the problem. We develop an upper bound and a lower bound that are submodular so that the Sandwich framework can be applied. We then devise a polling-based randomized algorithm that guarantees a data dependent approximation factor. Our experiments on four real data sets clearly verify the effectiveness and scalability of our method, as well as the advantage of our method against the other heuristic methods.
Autors: Zhefeng Wang;Yu Yang;Jian Pei;Lingyang Chu;Enhong Chen;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Nov 2017, volume: 29, issue:11, pages: 2374 - 2387
Publisher: IEEE
 
» Adaptable Blockchain-Based Systems: A Case Study for Product Traceability
Abstract:
Traceability allows tracking products through all stages of a supply chain, which is crucial for product quality control. To provide accountability and forensic information, traceability information must be secured. This is challenging because traceability systems often must adapt to changes in regulations and to customized traceability inspection processes. OriginChain is a real-world traceability system using a blockchain. Blockchains are an emerging data storage technology that enables new forms of decentralized architectures. Components can agree on their shared states without trusting a central integration point. OriginChain’s architecture provides transparent tamper-proof traceability information, automates regulatory compliance checking, and enables system adaptability.
Autors: Qinghua Lu;Xiwei Xu;
Appeared in: IEEE Software
Publication date: Nov 2017, volume: 34, issue:6, pages: 21 - 27
Publisher: IEEE
 
» Adaptive 3D Face Reconstruction from Unconstrained Photo Collections
Abstract:
Given a photo collection of “unconstrained” face images of one individual captured under a variety of unknown pose, expression, and illumination conditions, this paper presents a method for reconstructing a 3D face surface model of the individual along with albedo information. Unlike prior work on face reconstruction that requires large photo collections, we formulate an approach to adapt to photo collections with a high diversity in both the number of images and the image quality. To achieve this, we incorporate prior knowledge about face shape by fitting a 3D morphable model to form a personalized template, following by using a novel photometric stereo formulation to complete the fine details, under a coarse-to-fine scheme. Our scheme incorporates a structural similarity-based local selection step to help identify a common expression for reconstruction while discarding occluded portions of faces. The evaluation of reconstruction performance is through a novel quality measure, in the absence of ground truth 3D scans. Superior large-scale experimental results are reported on synthetic, Internet, and personal photo collections.
Autors: Joseph Roth;Yiying Tong;Xiaoming Liu;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Nov 2017, volume: 39, issue:11, pages: 2127 - 2141
Publisher: IEEE
 
» Adaptive Asymptotic Tracking Control of Uncertain Time-Driven Switched Linear Systems
Abstract:
This technical note establishes a novel result for adaptive asymptotic tracking control of uncertain switched linear systems. The result exploits a recently proposed stability condition for switched systems. In particular, a time-varying positive definite Lyapunov function is used to develop a novel piecewise continuous model-reference adaptive law and a dwell-time switching law. In contrast with previous research, where asymptotic tracking was possible only in the presence of a common Lyapunov function for the reference models, in this work asymptotic tracking is shown in a more general setting. Additionally, in the presence of persistence of excitation, the controller parameter estimation errors will converge to zero asymptotically. The main contribution of this work consists in establishing a symmetry between adaptive control of classical non-switched linear systems and adaptive control of switched linear systems. A practical example with an electro-hydraulic system is adopted to illustrate the results.
Autors: Shuai Yuan;Bart De Schutter;Simone Baldi;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5802 - 5807
Publisher: IEEE
 
» Adaptive Bus Encoding for Transition Reduction on Off-Chip Buses With Dynamically Varying Switching Characteristics
Abstract:
This paper presents an adaptive encoding framework for the reduction of transition activity in high-capacitance off-chip data buses, since power dissipation associated with those buses can be significant for high-speed communication. The technique relies on the observation of data characteristics over fixed window sizes and formation of cluster with bit lines having highly correlated switching patterns. The proposed method utilizes redundancy in space and time to prevent loss of information while retrieving data. We present analytical and experimental analyses, which demonstrate the activity reduction of our encoding scheme for various data. The extra power cost due to the encoder and decoder circuitry along with redundancy is offset due to reduced number of off-chip transitions.
Autors: Sumantra Sarkar;Ayan Biswas;Anindya Sundar Dhar;Rahul M. Rao;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3057 - 3066
Publisher: IEEE
 
» Adaptive Compensation of Traction System Actuator Failures for High-Speed Trains
Abstract:
In this paper, an adaptive failure compensation problem is addressed for high-speed trains with longitudinal dynamics and traction system actuator failures. Considered the time-varying parameters of the train motion dynamics caused by time-varying friction characteristics, a new piecewise constant model is introduced to describe the longitudinal dynamics with variable parameters. For both the healthy piecewise constant system and the system with actuator failures, the adaptive controller structure and conditions are derived to achieve the plant-model matching. The adaptive laws are designed to update the adaptive controller parameters, in the presence of the system piecewise constant parameters and actuator failure parameters which are unknown. Based on Lyapunov functions, the closed-loop stability and asymptotic state tracking are proved. Simulation results on a high-speed train model are presented to illustrate the performance of the developed adaptive actuator failure compensation control scheme.
Autors: Zehui Mao;Gang Tao;Bin Jiang;Xing-Gang Yan;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Nov 2017, volume: 18, issue:11, pages: 2950 - 2963
Publisher: IEEE
 
» Adaptive Digitization and Variable Channel Coding for Enhancement of Compressed Digital Mobile Fronthaul in PAM-4 Optical Links
Abstract:
The standardization and development of LTE-A and 5G introduced advanced wireless technologies including multiple-input multiple-output and carrier aggregation, which require multiple wireless carriers to be delivered to and from each remote radio head. The common public radio interface (CPRI) as the mainstream standard in mobile fronthaul (MFH) with on-off-keying-based optical links cannot fulfill the capacity and efficiency requirement. Instead, using compressed CPRI in a high-speed pulse-amplitude-modulation-4 (PAM-4) link is actively researched and demonstrated. In this paper, we propose and demonstrate adaptive digitization and channel coding based on these compression and capacity boosting technologies. Depending on the optical link condition, the digitization bits and channel coding rates can be adaptively and dynamically changed to achieve the lowest error vector magnitude (EVM) of wireless carriers. By separating digitization bits into high bits and low bits, the coding overhead can be different between groups, while still keeping the same bit rate per wireless carrier. Based on the existing digital MFH infrastructure, the proposed scheme can significantly improve the capacity and sensitivity in the PAM-4-based compressed digital MFH. Capacity gains from 30% to 68%, sensitivity improvement of 2-9 dB, and significant EVM improvements are demonstrated experimentally, comparing with other compressed CPRI MFH solutions.
Autors: Feng Lu;Mu Xu;Lin Cheng;Jing Wang;Shuyi Shen;Hyung Joon Cho;Gee-Kung Chang;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:21, pages: 4714 - 4720
Publisher: IEEE
 
» Adaptive Finite-Time Stabilization of a Class of Uncertain Nonlinear Systems via Logic-Based Switchings
Abstract:
In this paper, global adaptive finite-time stabilization is investigated by logic-based switching control for a class of uncertain nonlinear systems with the powers of positive odd rational numbers. Parametric uncertainties entering the state equations nonlinearly can be fast time-varying or jumping at unknown time instants, and the control coefficient appearing in the control channel can be unknown. The bounds of the parametric uncertainties and the unknown control coefficient are not required to know a priori. Our proposed controller is a switching-type one, in which a nonlinear controller with two parameters to be tuned is first designed by adding a power integrator, and then a switching mechanism is proposed to tune the parameters online to finite-time stabilize the system. An example is provided to demonstrate the effectiveness of the proposed result.
Autors: Jun Fu;Ruicheng Ma;Tianyou Chai;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5998 - 6003
Publisher: IEEE
 
» Adaptive Multiresolution Energy Consumption Prediction for Electric Vehicles
Abstract:
This paper introduces an adaptive multiresolution framework for electric vehicle (EV) energy consumption estimation with real-time capability. Three key parameters, namely powertrain efficiency, wind speed, and rolling resistance, are adaptively estimated using a two-step nonlinear iterative algorithm. Based on this algorithm, a multichannel framework for high-resolution powertrain efficiency estimation is introduced. Employing the “connected vehicles” concept, more reliable trip level energy estimates are achieved by sharing sensed environmental information. In addition, state-of-charge aware energy cost prediction methods of different accuracy and complexity are introduced to combat range anxiety and reduce computational complexity during times of high energy reserves. A variety of detailed simulations illustrate the introduced concept and its benefits for future EV systems.
Autors: Zonggen Yi;Peter H. Bauer;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10515 - 10525
Publisher: IEEE
 
» Adaptive Multiuser Scheduling for Simultaneous Wireless Information and Power Transfer in a Multicell Environment
Abstract:
Simultaneous wireless information and power transfer (SWIPT) is a promising technique to transmit information and harvest energy at the same time. In this paper, we investigate multiuser scheduling criteria in a multiuser SWIPT system taking into account co-channel interference in a multicell environment, where each transmitter operate independently. We propose an -adaptive scheduling scheme, which is able to adjust a scheduling criterion between maximizing achievable rate and maximizing harvested energy of the scheduled device by adjusting factor. Employing a power splitting receiver, we derive closed-form analytical results including cumulative distribution function (CDF) of the harvested energy, CDF of the achievable rate, average harvested energy, and average achievable rate. We also investigate the effect of adjustable factor in the proposed scheduling scheme and multiuser diversity in terms of the CDF of the harvested energy, the CDF of the achievable rate, and rate-energy tradeoff, compared with two conventional scheduling schemes: random scheduling and max-SNR scheduling. Our analytical results provide insightful information for designing multiuser scheduling criteria considering co-channel interference in the SWIPT systems.
Autors: Inkyu Bang;Su Min Kim;Dan Keun Sung;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Nov 2017, volume: 16, issue:11, pages: 7460 - 7474
Publisher: IEEE
 
» Adaptive Optimal Control for Large-Scale Nonlinear Systems
Abstract:
In this paper, we present an adaptive optimal control approach applicable to a wide class of large-scale nonlinear systems. The proposed approach avoids the so-called loss-of-stabilizability problem and the problem of poor transient performance that are typically associated with adaptive control designs. Moreover, it does not require the system model to be in a certain parameterized form, and most importantly, it is able to efficiently handle systems of large dimensions. Theoretical analysis establishes that the proposed methodology guarantees stability and exponential convergence to state trajectories that can be made as close as desired to the optimal ones. A numerical example demonstrates the capability of the proposed approach to overcome loss-of-stabilizability problems. Moreover, simulation experiments for energy-efficient climate control performed on a ten-office building demonstrate the effectiveness of the proposed approach in large-scale nonlinear applications.
Autors: Iakovos Michailidis;Simone Baldi;Elias B. Kosmatopoulos;Petros A. Ioannou;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5567 - 5577
Publisher: IEEE
 
» Adaptive RF Front-Ends Using Electrical-Balance Duplexers and Tuned SAW Resonators
Abstract:
This paper proposes an adaptive RF front-end (RFFE) architecture that uses an electrical-balance duplexer (EBD) and tuned surface acoustic wave (SAW) resonators to enable adaptive dual-frequency isolation suited for LTE’s frequency-division duplex (FDD) mode of operation. Alternatively, in the in-band full-duplex (IBFD) mode, the EBD cancels the in-band TX self-interference directly at RF for increased channel capacity. Furthermore, the EBD’s balance network is optimized to reduce the TX insertion loss (IL) below the nominal 3-dB limit in the FDD mode. A 0.18- SOI CMOS prototype implements the EBD, low-noise amplifier, and SAW-tuning capacitor banks. The chip is mounted to a module substrate together with the SAWs and matching components. The RFFE achieves >50-dB dual-frequency isolation and 2.6–3.4-dB TX IL in FDD mode, has +58/+42-dBm TX/RX-path IIP3 for an increased IBFD-link budget and handles up to +27.5-dBm TX power in both modes.
Autors: Barend van Liempd;Akshay Visweswaran;Saneaki Ariumi;Shinya Hitomi;Piet Wambacq;Jan Craninckx;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Nov 2017, volume: 65, issue:11, pages: 4621 - 4628
Publisher: IEEE
 
» Adaptive Secure Transmission for RF-EH Untrusted Relaying with Alien Eavesdropping
Abstract:
An adaptive cooperative scheme is proposed to improve the security of a wireless-powered relay network. A source node sends data to a destination node in the presence of an amplify-and-forward untrusted relay node and an alien eavesdropper where both are assumed to attempt to decode the source’s information signal. The source uses a fraction of its transmit power to send a jamming signal to keep its information confidential. To save energy, the energy-harvesting relay node transmits with the minimum power level that ensures secure transmissions. We derive a closed-form upper bound on the system’s secrecy outage probability. The proposed cooperative scheme is more efficient than the conventional scheme, where once the relay has accumulated sufficient energy, it assists the source’s information transmission.
Autors: Asma Mabrouk;Ahmed El Shafie;Kamel Tourki;Naofal Al-Dhahir;
Appeared in: IEEE Communications Letters
Publication date: Nov 2017, volume: 21, issue:11, pages: 2516 - 2519
Publisher: IEEE
 
» Adaptive Spur Cancellation Technique in All-Digital Phase-Locked Loops
Abstract:
The phenomenon of periodic phase errors (also known as spurs) in phase-locked loops (PLLs) is widely acknowledged and is responsible for posing considerable challenge on development of miniaturized wireless communication devices. The common approach employed today for spur mitigation calls for a digital notch filter within the receive chain, while there is no similar digital scheme for the transmit chain. In addition, this notch filter is not perfect and usually degrades the overall receiver sensitivity. This brief puts forward a novel idea, which is to cancel the spurs inside the PLL such that the local oscillator signal and consequently TX and RX antenna ports become spur-free. The technique is based on a least-mean squares algorithm that features a self-learning capability. The method has been silicon proven in a digital PLL of a transceiver radio test chip realized in a standard nanoscale CMOS technology.
Autors: Rotem Avivi;Michael Kerner;Evgeny Shumaker;Giuseppe Li Puma;Tami Sela;Lidor Sofer;Gil Horovitz;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Nov 2017, volume: 64, issue:11, pages: 1292 - 1296
Publisher: IEEE
 
» Adaptive Time Taps of STAP Under Channel Mismatch for GNSS Antenna Arrays
Abstract:
Although antenna arrays can effectively suppress interference and maintain the navigation signal integrity, interference suppression performance is limited by channel mismatch. However, a space-time adaptive processor (STAP) can reduce channel mismatch by introducing time taps within each element, which will further suppress the interference and improve the performance. However, interference suppression depends significantly on the number of time taps. This paper presents a proportion differentiation (PD) algorithm for the adaptive control of time taps based on the antenna arrays output power is presented. The effectiveness of the proposed algorithm is verified through simulations and measured data. The STAP with adaptive time taps has achieved excellent performance for interference suppression performance without increasing the computational load.
Autors: Zukun Lu;Junwei Nie;Feiqiang Chen;Huaming Chen;Gang Ou;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 2813 - 2824
Publisher: IEEE
 
» Additive Manufacturing of Bonded Nd–Fe–B—Effect of Process Parameters on Magnetic Properties
Abstract:
Isotropic-bonded magnets were fabricated by powder bed fusion additive manufacturing (AM) using a feedstock composed of polymeric binder polyamide 12 (PA-12) and a near stoichiometric Nd2Fe14B atomized nanocrystalline powder. The AM equipment constructed for that purpose uses a computer-controlled laser beam to melt the binder and build the parts layer by layer. Three process parameters were evaluated: layer thickness (LT), hatch spacing (HS), and laser power (LP). For the evaluation of magnetic properties, cylindrical samples with diameter and height of 10 mm were produced and measured in a hysteresisgraph. For a feedstock, based on a 34% volumetric fraction of PA-12, the highest density value achieved was 3.6 g/cm3, resulting in a remanence of 0.3 T. These relatively low values for remanence are due to the isotropic characteristic of the powder, the binder fraction, and the interparticle porosity not being completely eliminated. Results indicate that LT affects densification more significantly than LP and HS. Consequently, remanence follows the same trend. Coercivity has not been affected much by optimized process parameters, since the values of original atomized powder of around 700 kA/m remained practically the same. The overall conclusion shows encouraging results to explore this alternative AM technique to produce net shape permanent magnets.
Autors: A. B. Baldissera;P. Pavez;P. A. P. Wendhausen;C. H. Ahrens;J. M. Mascheroni;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Additive Manufacturing of Toroid Inductor for Power Electronics Applications
Abstract:
To increase power density and simplify the process of integrating magnetic components to power electronics circuits, a commercial multiextruder paste-extrusion three-dimensional (3-D) printer was used to process both metal and magnetic pastes into 3-D structures of magnetic components. A magnetic-filled-benzocyclobutene composite, termed poly-mag paste, was formulated and used as a magnetic core feedstock for the printer, and a commercial nanosilver paste was used as a conductive winding feedstock for the printer. A toroid inductor was 3-D printed by using metal and magnetic pastes, and it was cured at 250 °C for a half hour without any external pressure to form the structure. The inductance of the 3-D-printed toroid inductor was measured to be 167–143 nH in the frequency range of 1 kHz to 3 MHz. The dc resistance of the winding was 0.1 Ω. These results are in good agreement with a finite-element analysis simulation. Both the winding and core magnetic properties can be improved by adjusting the feed paste's formulations and flow characteristics, and by fine tuning the printer parameters, such as motor speeds, extrusion rate, and nozzle sizes.
Autors: Yi Yan;Jim Moss;Khai D. T. Ngo;Yunhui Mei;Guo-Quan Lu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5709 - 5714
Publisher: IEEE
 
» Advanced High Torque Density PM Vernier Machine With Multiple Working Harmonics
Abstract:
In recent years, permanent magnet (PM) vernier machines have gained more and more attention due to their high torque density and simple mechanical structure. However, PM vernier (PMV) machines with lap windings always suffer from long end winding length, and regular nonoverlapping winding may result in torque reduction for PMV machines. In this paper, an advanced PMV machine topology with multiple working harmonics is proposed. With specially designed stator auxiliary teeth, this topology could achieve ∼20% higher torque density than that of a regular nonoverlapping winding PMV machine, with the same magnet usage. Through finite element algorithm and theoretical analysis, the production of additional flux density harmonics and their contributions to back-electromotive force (EMF) are verified. Moreover, the electromagnetic performances of this novel machine topology, such as back-EMF and output torque, are quantitatively investigated with the geometric parameters’ effect considered. Finally, analysis results are verified by experimental test on a 21 Nm prototype, which is designed to have similar volume and weight with a 14 Nm regular commercial PM machine.
Autors: Tianjie Zou;Dawei Li;Ronghai Qu;Dong Jiang;Jian Li;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5295 - 5304
Publisher: IEEE
 
» Advancing Nonvolatile Computing With Nonvolatile NCFET Latches and Flip-Flops
Abstract:
Nonvolatile computing has been proven to be effective in dealing with power supply outages for on-chip check-pointing in emerging energy-harvesting Internet-of-Things applications. It also plays an important role in power-gating to cut off leakage power for higher energy efficiency. However, existing on-chip state backup solutions for D flip–flop (DFF) have a bottleneck of significant energy and/or latency penalties which limit the overall energy efficiency and computing progress. Meanwhile, these solutions rely on external control that limits compatibility and increases system complexity. This paper proposes an approach to fundamentally advancing the nonvolatile computing paradigm by intrinsically nonvolatile area-efficient latches and flip–flops designs using negative capacitance FET. These designs consume fJ-level energy and ns-level intrinsic latency for a backup plus restore operation, e.g., 2.4 fJ in energy and 1.1 ns in time for one proposed nonvolatile DFF with a supply power of 0.80 V.
Autors: Xueqing Li;Sumitha George;Kaisheng Ma;Wei-Yu Tsai;Ahmedullah Aziz;John Sampson;Sumeet Kumar Gupta;Meng-Fan Chang;Yongpan Liu;Suman Datta;Vijaykrishnan Narayanan;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Nov 2017, volume: 64, issue:11, pages: 2907 - 2919
Publisher: IEEE
 
» Affinely Adjustable Robust Model for Multiperiod Production Planning Under Uncertainty
Abstract:
Demand forecasting is an important factor in production planning, but future demand is not easy to forecast in practice. We consider a multiperiod, multiproduct production planning problem under demand uncertainty with constrains for raw materials, manufacturing capacity, and inventory. Under the assumption that probability distribution of demand is not available, two types of robust optimization models are proposed. First, a robust counterpart is developed to determine the here-and-now decision. Next, an affinely adjustable robust counterpart is developed to determine the wait-and-see decisions by approximating a robust solution with a linear decision rule. The robust models find an optimal solution that is always feasible and less sensitive against all realized demand within a given uncertainty set, in order to minimize production, procurement, inventory, and lost sales costs even in the worst case. Numerical studies demonstrated that, without knowing probability distribution of future demand, the affinely adjustable robust counterpart approach could outperform the robust counterpart and deterministic model in terms of the average cost, the standard deviation of the realized cost, and the worst-case scenario cost. The proposed method is much better than the others, especially when penalty cost due to lost sales is high and unknown demand is left skewed.
Autors: Byung Soo Kim;Byung Do Chung;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Nov 2017, volume: 64, issue:4, pages: 505 - 514
Publisher: IEEE
 
» Agents for Social Media
Abstract:
While currently intended for sharing personal content, future social media applications could support broader interactions, including business and government. Such applications could use agents that form communities, foster communications, vote, and collaborate to formulate policies and reach decisions. This special issue addresses several of the ways that software agent capabilities intersect with the demands of social media.
Autors: Pınar Yolum;Michael N. Huhns;
Appeared in: IEEE Internet Computing
Publication date: Nov 2017, volume: 21, issue:6, pages: 5 - 7
Publisher: IEEE
 
» aHDFS: An Erasure-Coded Data Archival System for Hadoop Clusters
Abstract:
In this paper, we propose an erasure-coded data archival system called aHDFS for Hadoop clusters, where codes are employed to archive data replicas in the Hadoop distributed file system or HDFS. We develop two archival strategies (i.e., aHDFS-Grouping and aHDFS-Pipeline) in aHDFS to speed up the data archival process. aHDFS-Grouping - a MapReduce-based data archiving scheme - keeps each mapper’s intermediate output Key-Value pairs in a local key-value store. With the local store in place, aHDFS-Grouping merges all the intermediate key-value pairs with the same key into one single key-value pair, followed by shuffling the single Key-Value pair to reducers to generate final parity blocks. aHDFS-Pipeline forms a data archival pipeline using multiple data node in a Hadoop cluster. aHDFS-Pipeline delivers the merged single key-value pair to a subsequent node’s local key-value store. Last node in the pipeline is responsible for outputting parity blocks. We implement aHDFS in a real-world Hadoop cluster. The experimental results show that aHDFS-Grouping and aHDFS-Pipeline speed up Baseline’s shuffle and reduce phases by a factor of 10 and 5, respectively. When block size is larger than 32 MB, aHDFS improves the performance of HDFS-RAID and HDFS-EC by approximately 31.8 and 15.7 percent, respectively.
Autors: Yuanqi Chen;Yi Zhou;Shubbhi Taneja;Xiao Qin;Jianzhong Huang;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Nov 2017, volume: 28, issue:11, pages: 3060 - 3073
Publisher: IEEE
 
» Air Cleaning Performance of a Novel Electrostatic Air Purifier Using an Activated Carbon Fiber Filter for Passenger Cars
Abstract:
We developed a novel electrostatic air purifier using a carbon fiber brush charger combined with a metallic collection rod and an activated carbon fiber (ACF) sheet to improve the indoor air quality of passenger vehicles. The ACF sheet was used to apply electrostatic forces to move charged particles toward a collection rod and simultaneously adsorb gas. The cylindrical air purifier (diameter: 100 mm, length: 190 mm) was composed of a conductive brush charger and an electrostatic collection rod for particle removal, as well as an ACF filter for gas removal. The flow rate of the device was approximately 209–360 L/min. The novel purifier was tested in a 1-m3 chamber with particles 0.3 μm in diameter and three gases: ammonia, acetic acid, and acetaldehyde. The gas cleaning performance of the purifier was compared with that of a commercial purifier with a high-efficiency particulate air (HEPA) filter, activated carbon pellets, and alumina balls. The clean air delivery rate (CADR) of the novel electrostatic air cleaner was 0.219 m3/min, 35% higher than that of the HEPA filter. The CADRs of the ESP air cleaner for the test gases were 0.25, 0.19, and 0.19 m3/min, respectively, indicating that the novel ESP air cleaner reduced the gases 308%, 204%, and 327%, respectively, faster than the commercial purifier.
Autors: Hak-Joon Kim;Bangwoo Han;Chang Gyu Woo;Yong-Jin Kim;Gi-Taek Lim;Weon Gyu Shin;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5867 - 5874
Publisher: IEEE
 
» Airborne DInSAR Results Using Time-Domain Backprojection Algorithm: A Case Study Over the Slumgullion Landslide in Colorado With Validation Using Spaceborne SAR, Airborne LiDAR, and Ground-Based Observations
Abstract:
The major impediment to accurate airborne repeat-pass differential synthetic aperture radar (SAR) interferometry (DInSAR) is compensating for aircraft motion caused by air turbulence. Various motion compensation (MoCo) procedures have been used in the airborne DInSAR processing to acquire reliable deformation mapping. In this paper, we present the use of time-domain backprojection (BP) algorithm for SAR focusing in an airborne DInSAR survey: No MoCo procedure is needed because the BP algorithm is inherently able to compensate for platform motion. In this study, we present the results of a pilot study aimed at demonstrating the feasibility of deformation mapping with an airborne SAR system based on the monitoring of the Slumgullion landslide in Colorado, USA between July 3 and 10 of 2015. The employed airborne SAR system is an Artemis SlimSAR that is a compact, modular, and multi-frequency radar system. Airborne light detection and ranging and global navigation satellite system (GNSS) observations, as well as spaceborne DInSAR results using COSMO-SkyMed (CSK) images, were used to verify the performance of the airborne SAR system. The surface velocities of the landslide derived from the airborne DInSAR observations showed good agreement with the GNSS and spaceborne DInSAR estimates. A three-dimensional deformation map of the Slumgullion landslide was also generated, which displayed distinct correlation between the landslide motion and topographic variation. This study shows that an inexpensive airborne L-band DInSAR system has the potential to measure centimeter level deformation with flexible temporal and spatial baselines.
Autors: Ning Cao;Hyongki Lee;Evan Zaugg;Ramesh Shrestha;William Carter;Craig Glennie;Guoquan Wang;Zhong Lu;Juan Carlos Fernandez-Diaz;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 4987 - 5000
Publisher: IEEE
 
» Albert Einstein - refrigerator technician? [Resources_History]
Abstract:
Albert Einstein is a legend for his breakthroughs in theoretical physics, but sometimes even the most abstract theorists have a practical side. In collaboration with other scientists and technologists throughout his career, Einstein also filed patents and promoted practical inventions that included a refrigerator, a hearing aid, and a camera.
Autors: Mark Anderson;
Appeared in: IEEE Spectrum
Publication date: Nov 2017, volume: 54, issue:11, pages: 19 - 19
Publisher: IEEE
 
» All-Digital Time-Mode Direct-Form All-Pole Biquadratic Filter Realization
Abstract:
In this brief, the design of time-mode signal processing (TMSP) circuits having an all-digital advantage is introduced and experimental data covering all necessary aspects of operation such as frequency response are presented. TMSP building blocks were used to design two second-order filter prototypes having Butterworth and Chebychev I responses demonstrating peak signal-to-noise-plus-distortion values of 47 dB and 37 dB, respectively, making it a good candidate for data conversion applications.
Autors: Moataz Abdelfattah;Gordon W. Roberts;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Nov 2017, volume: 64, issue:11, pages: 1262 - 1266
Publisher: IEEE
 
» Alternative Scheduling Decisions for Multipath TCP
Abstract:
In this letter, we discuss the impact of packet scheduling decisions on the performance of Multipath Transmission Control Protocol (MPTCP) flows. We propose, implement, and evaluate three alternative schedulers, namely, Highest Sending Rate (HSR), Largest Window Space (LWS) and Lowest Time/Space (LTS). We evaluate and compare them to the current MPTCP’s scheduler, Lowest Latency (LL), in an experimental environment. To analyze the performance of the multipath throughput improvement of these schedulers, we conducted a vast set of 40 different experiments that combine homogeneous and heterogeneous link parameterizations, considering packet loss rate, delay, and transmission rate. Experimental results showed that the proposed alternatives achieved a higher performance than LL in most of the experiments, allowing better alternatives for improving multipath throughput with paths under loss, delay, and varied transmission rates.
Autors: Bruno Y. L. Kimura;Demetrius C. S. F. Lima;Antonio A. F. Loureiro;
Appeared in: IEEE Communications Letters
Publication date: Nov 2017, volume: 21, issue:11, pages: 2412 - 2415
Publisher: IEEE
 
» Amplifying the Randomness of Weak Sources Correlated With Devices
Abstract:
The problem of device-independent randomness amplification against no-signaling adversaries has so far been studied under the assumption that the weak source of randomness is uncorrelated with the (quantum) devices used in the amplification procedure. In this paper, we relax this assumption, and reconsider the original protocol of Colbeck and Renner using a Santha-Vazirani (SV) source. To do so, we introduce an SV-like condition for devices, namely that any string of SV source bits remains weakly random conditioned upon any other bit string from the same SV source and the outputs obtained when this further string is input into the devices. Assuming this condition, we show that a quantum device using a singlet state to violate the chained Bell inequalities leads to full randomness in the asymptotic scenario of a large number of settings, for a restricted set of SV sources (with ). We also study a device-independent protocol that allows for correlations between the sequence of boxes used in the protocol and the SV source bits used to choose the particular box from whose output the randomness is obtained. Assuming the SV-like condition for devices, we show that the honest parties can achieve amplification of the weak source, for the parameter range , against a class of attacks given as a mixture of product box sequences, made of extremal no-signaling boxes, with additional symmetry conditions. Composable security proof against this class of attacks is provided.
Autors: Hanna Wojewódka;Fernando G. S. L. Brandão;Andrzej Grudka;Karol Horodecki;Michał Horodecki;Paweł Horodecki;Marcin Pawłowski;Ravishankar Ramanathan;Maciej Stankiewicz;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 7592 - 7611
Publisher: IEEE
 
» An 80-mVpp Linear-Input Range, 1.6- $text{G}Omega $ Input Impedance, Low-Power Chopper Amplifier for Closed-Loop Neural Recording That Is Tolerant to 650-mVpp Common-Mode Interference
Abstract:
Closed-loop neuromodulation is essential for the advance of neuroscience and for administering therapy in patients suffering from drug-resistant neurological conditions. Neural stimulation generates large differential and common-mode (CM) artifacts at the recording sites, which easily saturate traditional recording front ends. This paper presents a neural recording chopper amplifier capable of handling in-band 80-mVpp differential artifacts and 650-mVpp CM artifacts while preserving the accompanying small neural signals. New techniques have been proposed that introduce immunity to CM interference, increase the input impedance of the chopper amplifier to 1.6 , and increase the maximum realizable resistance of duty-cycled resistors (DCR) to 90 . These techniques enable our recording front-end to achieve a dynamic range of 74 dB (200 Hz–5 kHz) and 81 dB (1–200 Hz). Implemented in a 40-nm CMOS process, the prototype occupies an area of 0.069 mm2/channel, and consumes 2.8 from a 1.2-V supply. The input-referred noise is 5.3 (200 Hz–5 kHz) and 1.8 (1–200Hz). The total harmonic distortion for a 40-mV input at 1 kHz is −76 dB. This work improves the input impedance by 5.3 for chopped- front-ends, linear-input range by 2, maximum resistance of DCR by 32, and tolerance to CM interferers by 6.5, while maintaining comparable power and noise performance.
Autors: Hariprasad Chandrakumar;Dejan Marković;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Nov 2017, volume: 52, issue:11, pages: 2811 - 2828
Publisher: IEEE
 
» An Accurate Two-Step ISAR Cross-Range Scaling Method for Earth-Orbit Target
Abstract:
Inverse synthetic aperture radar (ISAR) cross-range scaling is used to obtain the actual cross-range size of the target, which is essential for space surveillance and automatic target recognition. In this letter, a novel two-step ISAR cross-range scaling method for earth-orbit targets is proposed, which improves the computational efficiency through the use of prior information and achieves high estimation accuracy. An initial rotation velocity (RV) is calculated first using the open two-line element data of the satellite orbit to coarsely achieve a cross-range scaling of the ISAR image with high efficiency. Then, the refined cross-range scaling result is obtained with an accurate RV, which is accomplished by the isolated scatterer extraction and the chirp-rate estimation, wherein the blob detection and the integrated cubic phase function are employed, respectively. The initial RV is used to narrow the search width of the chirp-rate estimation, and the corresponding computational burden is expected to decrease accordingly. Finally, simulations and real-data experiments are performed to verify the effectiveness and the accuracy of the proposed method.
Autors: Yuhan Du;Yicheng Jiang;Wei Zhou;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 1893 - 1897
Publisher: IEEE
 
» An Active Interferometric Method for Extreme Impedance On-Wafer Device Measurements
Abstract:
Nano-scale devices and high-power transistors present extreme impedances, which are far removed from the 50- reference impedance of conventional test equipment, resulting in a reduction in the measurement sensitivity as compared with impedances close to the reference impedance. This letter describes a novel method based on active interferometry to increase the measurement sensitivity of a vector network analyzer for measuring such extreme impedances, using only a single coupler. The theory of the method is explained with supporting simulation. An interferometry-based method is demonstrated for the first time with on-wafer measurements, resulting in an improved measurement sensitivity for extreme impedance device characterization of up to 9%.
Autors: Haris Votsi;Chong Li;Peter H. Aaen;Nick M. Ridler;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Nov 2017, volume: 27, issue:11, pages: 1034 - 1036
Publisher: IEEE
 
» An Adaptive Control Architecture for Mitigating Sensor and Actuator Attacks in Cyber-Physical Systems
Abstract:
Recent technological advances in communications and computation have spurred a broad interest in control law architectures involving the monitoring, coordination, integration, and operation of sensing, computing, and communication components that tightly interact with the physical processes that they control. These systems are known as cyber-physical systems and due to their use of open computation and communication platform architectures, controlled cyber-physical systems are vulnerable to adversarial attacks. In this technical note, we propose a novel adaptive control architecture for addressing security and safety in cyber-physical systems. Specifically, we develop an adaptive controller that guarantees uniform ultimate boundedness of the closed-loop dynamical system in the face of adversarial sensor and actuator attacks that are time-varying and partial asymptotic stability when the sensor and actuator attacks are time-invariant. Finally, we provide a numerical example to illustrate the efficacy of the proposed adaptive control architecture.
Autors: Xu Jin;Wassim M. Haddad;Tansel Yucelen;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 6058 - 6064
Publisher: IEEE
 
» An Adaptive Control Scheme of SPV System Integrated to AC Distribution System
Abstract:
This paper presents a single-stage solar photovoltaic (SPV) system utilizing an adaptive control scheme. The SPV system includes SPV array, voltage source converter (VSC), ripple filter, nonlinear loads, and a distribution network. The proposed SPV system feeds the active power to the distribution system, provides an effective use of SPV array and mitigation of load harmonics currents. The SPV system with an incremental conductance based control scheme is used for obtaining the maximum power from the SPV array and an adaptive control scheme to control the switching pulses of the VSC. In addition, it utilizes a SPV feed-forward loop to improve the dynamic response and reduces the burden on the proportional-integral controller by regulating dc bus voltage. Test results are presented to validate the control, design, and response of SPV system with various states.
Autors: Shailendra Kumar;Ikhlaq Hussain;Bhim Singh;Ambrish Chandra;Kamal Al-Haddad;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5173 - 5181
Publisher: IEEE
 
» An Adaptive Overcurrent Coordination Scheme to Improve Relay Sensitivity and Overcome Drawbacks due to Distributed Generation in Smart Grids
Abstract:
Distributed generation (DG) brought new challenges for protection engineers since standard relay settings of traditional system may no longer function properly under increasing presence of DG. The extreme case is coordination loss between primary and backup relays. The directional overcurrent relay (DOCR), which is the most implemented protective device in the electrical network, also suffers performance degradation in the presence of DG. Therefore, this paper proposes the mitigation of DG impact on DOCR coordination employing adaptive protection scheme (APS) using differential evolution algorithm while improving overall sensitivity of relays. The impacts of DG prior and after the application of APS are presented based on interconnected 6 bus and IEEE 14 bus system. As a consequence, general sensitivity improvement and mitigation scheme is proposed.
Autors: Meng Yen Shih;Arturo Conde;Zbigniew Leonowicz;Luigi Martirano;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Nov 2017, volume: 53, issue:6, pages: 5217 - 5228
Publisher: IEEE
 

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