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Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 05-2017 trié par par titre, page: 5
» Highly Sensitive Twist Sensor Based on Temperature- and Strain-Independent Fiber Lyot Filter
Résumé:
A novel highly sensitive optical fiber twist sensor based on a Lyot filter is proposed and experimentally demonstrated in this paper. The evolution of the transmission spectra of the Lyot filter with respect to twist, temperature, and strain are investigated, respectively. The amplitude of the resonance dip changes as a sine-like function with the twist angle varying, which agrees well with the theoretical analysis. Based on analyzing the amplitude response of the resonance dip, the sensitivities of the sensor with respect to twist, temperature, and strain are found to be −15.586 dB/rad, 0.003 dB/°C, and −0.001 dB/μϵ, indicating the viability of implementing a temperature- and strain-independent twist sensor based on a Lyot filter.
Auteurs: Bo Huang;Xuewen Shu;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 2026 - 2031
Editeur: IEEE
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» Highly Tunable Triangular Wave UWB Baseband Pulse Generator With Amplitude Stabilization in 40-nm CMOS
Résumé:
This brief introduces a highly configurable ultrawideband triangular wave baseband pulse generator designed in 40-nm complementary metal–oxide–semiconductor technology. The baseband pulse width is adjustable between 660 ps and 3.8 ns. An extra amplitude compensation loop is implemented to prevent amplitude changes when the pulse width varies. The amplitude variations are limited to 13% compared with the maximum amplitude over the entire pulse width range. The amplitude compensation loop allows a pulse amplitude tuning range between 280 and 640 mV, whereas the pulse width only varies 80 ps over this entire range. The pulse generator has a maximum simulated signal-to-noise ratio of 59 dB and a measured maximum power consumption of 6.2 pJ/pulse from a 0.9-V power supply and a 100-MHz pulse repetition frequency.
Auteurs: B. Faes;P. Reynaert;P. Leroux;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 505 - 509
Editeur: IEEE
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» History of Aircraft Wiring Arc-Fault Protection [History]
Résumé:
In both new and aging military and civilian aircraft, all critical power wiring has been typically protected against overheating by using combinations of thermal and magnetic circuit breakers or solid-state power controllers (SSPCs). However, the conventional types of these protective devices do not detect and react to hazardous arcing faults, and it is important that they do so to mitigate the risk of aircraft fires caused by aging, damaged insulation, wire chafing, wire breakage, chemical exposure, maintenance procedures, and contamination. Most aircraft electrical systems operate at 115 Vac, 400 Hz, both single and three phase. In addition to this ac power, they utilize 28 Vdc. Hazardous arcing faults can occur in all these power systems between parallel conductors, to ground, or in series (due to a broken or frayed wire or at a loose connection).
Auteurs: Barry C. Brusso;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 6 - 11
Editeur: IEEE
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» Holographic and Light-Field Imaging as Future 3-D Displays
Résumé:
Light-field imaging and holographic imaging are currently the two mostly investigated 3-D imaging technologies because of their potentials to create the viewing environment conforming to a natural viewing condition. The basic optical geometries for image display in these imaging are not different from that of integral photography. The images in the two type of imaging are a set of different view images. These images are arranged as a 2-D point image array, and each point image is expanded with a certain angle to form a viewing zone. The differences between the two types of imaging are the number of point images in the array and the physical entities forming the images. Holographic imaging has many more point images than light-field imaging, and each image in the array consists of coherent right rays from different positions of an object. In light-field imaging, an array of pixels represents a direction view of the object. Despite these differences, they share the same goal of providing a continuous parallax to viewers and require display panels of almost the same characteristics. It is expected that in the future these two imaging techniques will be integrated into the same flat panel along with the plane image.
Auteurs: Jung-Young Son;Hyoung Lee;Beom-Ryeol Lee;Kwang-Hoon Lee;
Apparue dans: Proceedings of the IEEE
Date publication: 05.-2017, volume: 105, issue:5, pages: 789 - 804
Editeur: IEEE
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» Hot-Electron Electroluminescence Under RF Operation in GaN-HEMTs: A Comparison Among Operational Classes
Résumé:
Electroluminescence microscopy and spectroscopy are used to compare the average hot-electron concentration and temperature under radio frequency (RF) operation class A, class B, and class F modes. From the results obtained, class A results, on average, in the highest hot-electron concentration, while class F is the mode with the lowest concentration due to its “L”-shaped load line. The electron temperature extracted from the electroluminescence spectra is reduced with increasing RF power, reflecting the dominance of electroluminescence from the portion of the load line in the semi-on region. The electroluminescence method is not able to give substantial information on the portion of the load line with high field and low current density which will be responsible for the potentially damaging hottest electrons present in the channel.
Auteurs: Tommaso Brazzini;Michael A. Casbon;Michael J. Uren;Paul J. Tasker;Helmut Jung;Hervé Blanck;Martin Kuball;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2155 - 2160
Editeur: IEEE
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» How Computer Science Departments and Faculty Can Contribute to the CS for All Initiative
Résumé:
As the role of computer science becomes increasingly central to our way of life, ensuring the successful education of future computer scientists is imperative.
Auteurs: W. Richards Adrion;
Apparue dans: Computer
Date publication: 05.-2017, volume: 50, issue:5, pages: 103 - 105
Editeur: IEEE
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» How Do Informal Ties Drive Open Innovation? The Contingency Role of Market Dynamism
Résumé:
Scholars and practitioners have recently shifted their attention from traditional closed internal innovation to open innovation (OI). Building on both the resource-based view and the network perspective, we explore the roles of three types of informal ties (i.e., business, government, and university) in driving inbound and outbound OI, and further examine such effects contingent on market dynamism. Empirical results from our study of 260 Chinese firms show that all three types of informal ties positively affect inbound innovation openness, whereas only business ties facilitate outbound innovation openness. In addition, market dynamism strengthens the relationship between university ties and inbound innovation openness, but weakens the effect of business ties on inbound innovation openness. These findings indicate the salience of informal ties in increasing innovation openness and the contingent role of external market conditions. The findings contribute to the understanding of the drivers of innovation openness, and help clarify the differences between inbound and outbound OI.
Auteurs: Xiaoxuan Zhu;Maggie Chuoyan Dong;Jibao Gu;Wenyu Dou;
Apparue dans: IEEE Transactions on Engineering Management
Date publication: 05.-2017, volume: 64, issue:2, pages: 208 - 219
Editeur: IEEE
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» Hull Structure Monitoring Using Inertial Measurement Units
Résumé:
Hull structure monitoring is needed to provide healthy suggestions for a ship. Inertial Measurement Units (IMUs) are available for this application. By installing IMUs on different points of the ship hull, the angular velocity and acceleration of each point can be measured. Once the hull flexure changes, the movement parameters of those points will be different, and the hull flexure can be estimated through matching these parameters by a Kalman filter. We deduced proper measurement equations of the Kalman filter, which is essential for the flexure estimation, and designed real data and simulation data experiments to verify the equation. Results showed that the hull structure can be effectively monitored by the proposed method.
Auteurs: Xianglu Ma;Shiqiao Qin;Xingshu Wang;Wei Wu;Jiaxing Zheng;Yao Pan;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2676 - 2681
Editeur: IEEE
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» Human Activity Classification With Transmission and Reflection Coefficients of On-Body Antennas Through Deep Convolutional Neural Networks
Résumé:
We propose to classify human activities based on transmission coefficient ( $S_{21}$ ) and reflection coefficient ( $S_{11}$ ) of on-body antennas with deep convolutional neural networks (DCNNs). It is shown that spectrograms of $S_{21}$ and $S_{11}$ exhibit unique time-varying signatures for different body motion activities that can be used for classification purposes. DCNN, a deep learning approach, is applied to spectrograms to learn the necessary features and classification boundaries. It is found that DCNN can achieve classification accuracies of 98.8% using $S_{21}$ and 97.1% using $S_{11}$ . The effects of operating frequency and antenna location on the accuracy have been investigated.
Auteurs: Youngwook Kim;Yang Li;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2764 - 2768
Editeur: IEEE
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» Hybrid Precoding via Successive Refinement for Millimeter Wave MIMO Communication Systems
Résumé:
We propose a hybrid precoding design for spatial multiplexing in millimeter wave massive multiple-input multiple-output systems. The proposed design relies on the popular orthogonal matching pursuit (OMP) algorithm. The OMP algorithm uses necessary columns of the right/left (for receiver/transmitter) unitary matrix of the channel (obtained via a singular value decomposition) to obtain the initial baseband (digital) precoder using principles of basis pursuit. The resulting baseband precoder is then used to refine the RF (analog) precoder. This iterative refinement improves the quality of hybrid preocders. Quantization of the RF and baseband precoding matrices is also discussed for limited feedback systems, where the high-dimensional RF precoder is quantized using codebooks generated using the $K-$ means clustering algorithm. On the other hand, the low-dimensional baseband precoder is quantized using well-known Grassmannian codebooks. Simulation results show that the proposed scheme performs close to the fully digital precoding scheme.
Auteurs: Jawad Mirza;Bakhtiar Ali;Syed Saud Naqvi;Saqib Saleem;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 991 - 994
Editeur: IEEE
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» Hyper-Heuristic Based Product Selection for Software Product Line Testing
Résumé:
A Software Product Line (SPL) is defined as a set of software systems that share a common and managed set of features satisfying specific needs of a particular market segment or domain [1]. The SPL offers a number of common artifacts for building products, including mandatory and variable elements. SPL approaches have been adopted by many software companies1 to ease reuse and reduce time and production costs. A feature represents a functionality that is visible to the user and can be designed as a variability, which represents a variable functionality that may or may not be present in a product. On the other hand, mandatory features are common to all SPL products. To facilitate feature management, most SPL methodologies use the Feature Model (FM) [2] to represent all the SPL variabilities and commonalities.
Auteurs: Thiago N. Ferreira;Jackson A. Prado Lima;Andrei Strickler;Josiel N. Kuk;Silvia R. Vergilio;Aurora Pozo;
Apparue dans: IEEE Computational Intelligence Magazine
Date publication: 05.-2017, volume: 12, issue:2, pages: 34 - 45
Editeur: IEEE
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» Hyperbolic Harmonic Mapping for Surface Registration
Résumé:
Automatic computation of surface correspondence via harmonic map is an active research field in computer vision, computer graphics and computational geometry. It may help document and understand physical and biological phenomena and also has broad applications in biometrics, medical imaging and motion capture industries. Although numerous studies have been devoted to harmonic map research, limited progress has been made to compute a diffeomorphic harmonic map on general topology surfaces with landmark constraints. This work conquers this problem by changing the Riemannian metric on the target surface to a hyperbolic metric so that the harmonic mapping is guaranteed to be a diffeomorphism under landmark constraints. The computational algorithms are based on Ricci flow and nonlinear heat diffusion methods. The approach is general and robust. We employ our algorithm to study the constrained surface registration problem which applies to both computer vision and medical imaging applications. Experimental results demonstrate that, by changing the Riemannian metric, the registrations are always diffeomorphic and achieve relatively high performance when evaluated with some popular surface registration evaluation standards.
Auteurs: Rui Shi;Wei Zeng;Zhengyu Su;Jian Jiang;Hanna Damasio;Zhonglin Lu;Yalin Wang;Shing-Tung Yau;Xianfeng Gu;
Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence
Date publication: 05.-2017, volume: 39, issue:5, pages: 965 - 980
Editeur: IEEE
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» Hyperspectral and Lidar Intensity Data Fusion: A Framework for the Rigorous Correction of Illumination, Anisotropic Effects, and Cross Calibration
Résumé:
The fusion of hyperspectral imaging (HSI) sensor and airborne lidar scanner (ALS) data provides promising potential for applications in environmental sciences. Standard fusion approaches use reflectance information from the HSI and distance measurements from the ALS to increase data dimensionality and geometric accuracy. However, the potential for data fusion based on the respective intensity information of the complementary active and passive sensor systems is high and not yet fully exploited. Here, an approach for the rigorous illumination correction of HSI data, based on the radiometric cross-calibrated return intensity information of ALS data, is presented. The cross calibration utilizes a ray tracing-based fusion of both sensor measurements by intersecting their particular beam shapes. The developed method is capable of compensating for the drawbacks of passive HSI systems, such as cast and cloud shadowing effects, illumination changes over time, across track illumination, and partly anisotropy effects. During processing, spatial and temporal differences in illumination patterns are detected and corrected over the entire HSI wavelength domain. The improvement in the classification accuracy of urban and vegetation surfaces demonstrates the benefit and potential of the proposed HSI illumination correction. The presented approach is the first step toward the rigorous in-flight fusion of passive and active system characteristics, enabling new capabilities for a variety of applications.
Auteurs: Maximilian Brell;Karl Segl;Luis Guanter;Bodo Bookhagen;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 05.-2017, volume: 55, issue:5, pages: 2799 - 2810
Editeur: IEEE
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» Hyperspectral Image Classification Using Metric Learning in One-Dimensional Embedding Framework
Résumé:
Hyperspectral image (HSI) classification has become an active research area in the remote sensing field. In order to construct a simple and reliable classifier, learning an adequate distance metric from a given HSI dataset is still a critical and challenging task in many HSI applications. In this paper, a novel distance metric learning (DML) framework based on 1-D manifold embedding (1DME), named DL1DME, is proposed for HSI classification. The 1DME framework was developed by using the recently developed smooth ordering technique. This framework enables us to elaborately exploit the benefits of DML in the development of the 1DME algorithm. The core of the state-of-the-art DML is to learn a Mahalanobis matrix from the given dataset that better describes the similarity between pixels. Largest margin nearest neighbors (LMNN) and information theoretic metric learning (ITML) are employed for the Mahalanobis matrix learning. Then, based on the affinity defined by the Mahalanobis matrix, the preclassifiers are constructed using the simple 1-D regularization on 1DME; and they predict the labels of the test data. By a voting rule, the pixels labeled in the same class by most of the preclassifiers are voted into the confidently predicted set, which are then merged with the current labeled set. The labeled set enlargement process is repeated if the original one has a very small size. The final classifier is then constructed in the 1DME framework again, but based on the enlarged labeled set. According to the aforementioned strategy, two novel DML-based 1DME classification algorithms, DL1DME-LMNN and DL1DME-ITML, are developed in this paper. Experimental results on three popular real-world HSIs demonstrate that the classification performance of the proposed DL1DME is superior to other most popular SSL methods in terms of classification accuracies.
Auteurs: Huiwu Luo;Yuan Yan Tang;Yulong Wang;Jianzhong Wang;Robert P. Biuk-Aghai;Jianjia Pan;Runzong Liu;Lina Yang;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 05.-2017, volume: 10, issue:5, pages: 1987 - 2001
Editeur: IEEE
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» Hyperspectral Image Superresolution by Transfer Learning
Résumé:
Hyperspectral image superresolution is a highly attractive topic in computer vision and has attracted many researchers’ attention. However, nearly all the existing methods assume that multiple observations of the same scene are required with the observed low-resolution hyperspectral image. This limits the application of superresolution. In this paper, we propose a new framework to enhance the resolution of hyperspectral images by exploiting the knowledge from natural images: The relationship between low/high-resolution images is the same as that between low/high-resolution hyperspectral images. In the proposed framework, the mapping between low- and high-resolution images can be learned by deep convolutional neural network and be transferred to hyperspectral image by borrowing the idea of transfer learning. In addition, to study the spectral characteristic between low- and high-resolution hyperspectral image, collaborative nonnegative matrix factorization (CNMF) is proposed to enforce collaborations between the low- and high-resolution hyperspectral images, which encourages the estimated solution to extract the same endmembers with low-resolution hyperspectral image. The experimental results on ground based and remote sensing data suggest that the proposed method achieves comparable performance without requiring any auxiliary images of the same scene.
Auteurs: Yuan Yuan;Xiangtao Zheng;Xiaoqiang Lu;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 05.-2017, volume: 10, issue:5, pages: 1963 - 1974
Editeur: IEEE
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» iASK: A Distributed Q&A System Incorporating Social Community and Global Collective Intelligence
Résumé:
Traditional web-based Question and Answer (Q&A) websites cannot easily solve non-factual questions to match askers’ preference. Recent research efforts begin to study social-based Q&A systems that rely on an asker's social friends to provide answers. However, this method cannot find answerers for a question not belonging to the asker's interests. To solve this problem, we propose a distributed Q&A system incorporating both social community intelligence and global collective intelligence, named as iASK. iASK improves the response latency and answer quality in both the social domain and global domain. It uses a neural network based friend ranking method to identify answerer candidates by considering social closeness and Q&A activities. To efficiently identify answerers in the global user base, iASK builds a virtual server tree that embeds the hierarchical structure of interests, and also maps users to the tree based on user interests. To accurately locate the cooperative experts, iASK has a fine-grained reputation system to evaluate user reputation based on their cooperativeness and expertise, and uses a reputation based reward strategy to encourage users to be cooperative. To further improve the performance of iASK, we propose a weak tie assisted social based potential answerer location algorithm and an interest coefficient based uncategorized question forwarding algorithm. To further improve the response quality and cooperativeness, we propose a reputation based reward strategy that motivates users to answer questions from unknown users. Experimental results from large-scale trace-driven simulation and real-world daily usages of the iASK prototype show the superior performance of iASK. It achieves high answer quality with 24 percent higher accuracy, short response latency with 53 percent less delay and effective cooperative incentives with 16 percent more answers compared to other social-based Q&A systems. Th- results also show the effectiveness of the enhancement algorithms in improving the performance of iASK.
Auteurs: Guoxin Liu;Haiying Shen;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 05.-2017, volume: 28, issue:5, pages: 1346 - 1360
Editeur: IEEE
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» iCAP: An Individualized Model Combining Gaze Parameters and Image-Based Features to Predict Radiologists’ Decisions While Reading Mammograms
Résumé:
This study introduces an individualized tool for identifying mammogram interpretation errors, called eye-Computer Assisted Perception (iCAP). iCAP consists of two modules, one which processes areas marked by radiologists as suspicious for cancer and classifies these as False Positive (FP) or True Positive (TP) decisions, while the second module classifies fixated but not marked locations as False Negative (FN) or True-Negative (TN) decisions. iCAP relies on both radiologists’ gaze-related parameters, extracted from eye tracking data, and image-based features. In order to evaluate iCAP, eye tracking data from eight breast radiologists reading 120 two-view digital mammograms were collected. Fifty-nine cases had biopsy proven cancer. For each radiologist, a user-specific support vector machine model was built to classify the radiologist’ s reported areas as TPs or FPs and fixated locations as TNs or FNs. The performances of the classifiers were evaluated by utilizing leave-one-out cross validation. iCAP was tested retrospectively in a simulated scenario in which it was assumed that the radiologists would accept all iCAP decisions. Using iCAP led to an average increase of 12%±6% in the number of correctly localized cancer and an average decrease of 44.5%±22.7% in the number of FPs per image.
Auteurs: Ziba Gandomkar;Kevin Tay;Will Ryder;Patrick C. Brennan;Claudia Mello-Thoms;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 05.-2017, volume: 36, issue:5, pages: 1066 - 1075
Editeur: IEEE
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» Idea Identification Model to Support Decision Making
Résumé:
Innovation is not a trivial process and ideas are the raw material of this process. Oriented systems to idea management domain seek to identify and develop effective and efficient ideas. However, there are challenges such as information overload with ideas submissions peaks and trivial description of collecting ideas, thereby making the process of selection and identification of relevant ideas. By using clustering techniques can bring together groups of like-minded and easy viewing of information. The objective of this study is to present an ontology-based model and cluster analysis to support the Idea Management, to contribute in the decision making process. The demonstration of feasibility of the proposed model was through the development of a prototype. The prototype was used in both study scenarios using ideas collected on the websites of Starbucks® and Dell® companies. It was found that when analyzing groups of similar ideas, patterns and trends can be highlighted. As a result presents a model to assist in decision making and in the process of identification and selection of ideas for implementation.
Auteurs: Marina Carradore Sergio;Joao Artur de Souza;Alexandre Leopoldo Goncalves;
Apparue dans: IEEE Latin America Transactions
Date publication: 05.-2017, volume: 15, issue:5, pages: 968 - 973
Editeur: IEEE
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» Ideal Codes Over Separable Ring Extensions
Résumé:
In this paper, an application of the theoretical algebraic notion of a separable ring extension in the realm of cyclic convolutional codes or, more generally, ideal codes, is investigated. It is worked under very mild conditions that cover all previously known as well as new non-trivial examples. It is proved that ideal codes are direct summands, as left ideals, of the underlying non-commutative algebra, in analogy with cyclic block codes. This implies, in particular, that they are generated by a non-commutative idempotent polynomial. Hence, by using a suitable separability element, an efficient algorithm for computing one of such idempotents is designed. We show that such an idempotent generator polynomial can be used to get information on the free distance of the convolutional code.
Auteurs: José Gómez-Torrecillas;F. J. Lobillo;Gabriel Navarro;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 2796 - 2813
Editeur: IEEE
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» Identification and Trajectory Tracking Control of Nonlinear Singularly Perturbed Systems
Résumé:
In this paper, a new identification and control scheme using multitime scale recurrent high-order neural networks is proposed to control the singularly perturbed nonlinear systems with uncertainties. First, a novel identification scheme using modified optimal bounded ellipsoid based weight's updating laws is developed to identify the unknown nonlinear systems. By adding two additional terms to the original optimal bounded ellipsoid based weight's updating laws, the new modified identification scheme can achieve high convergence speed due to the adaptively adjusted learning gain at the beginning of the identification process and remain effective during the whole identification process. Based on the identified model, a new indirect adaptive control scheme for trajectory tracking problem using singular perturbation theory is developed, which is different from the control scheme proposed previously that can only be applied to a regulation problem. The closed-loop stability is analyzed and the convergence of system states is guaranteed. Experimental results are presented to demonstrate the effectiveness of the identification and control scheme.
Auteurs: Dong-Dong Zheng;Wen-Fang Xie;Tianyou Chai;Zhijun Fu;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3737 - 3747
Editeur: IEEE
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» Identification of Discrete-Time Output Error Model Using Filtered Input Excitation for Integrating Processes With Time Delay
Résumé:
A discrete-time output error (OE) model identification method is proposed for industrial integrating processes with time delay, to facilitate the discrete-time controller design and implementation in sampled systems. By subtly introducing a differential filter to the input excitation, an open-loop identification test can be performed for such a process while complying with the output limit. Correspondingly, the parameter estimation is equivalently transformed to identify a stable type OE model with time delay. A recursive identification algorithm is developed to simultaneously estimate all the model parameters including the integer delay, and a linear interpolation of the input excitation is given for the recursive computation to guarantee consistent estimation. The convergence of parameter estimation is analyzed with a proof. An illustrative example is used to demonstrate the effectiveness of the proposed method.
Auteurs: Tao Liu;Shijian Dong;Fengwei Chen;Dewei Li;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2524 - 2530
Editeur: IEEE
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» Identification of Simultaneously Congested Transmission Lines in Power Systems Operation and Market Analysis
Résumé:
The number and locations of transmission lines that are likely to get simultaneously congested are useful information for analysis of power market. In this paper, we present a study that demonstrates the number of simultaneously congested transmission lines is very limited, as well as an algorithm for identifying a small set of transmission lines that may become simultaneously congested based on the current states of the system and market. To this end, we first investigate the maximum number of simultaneously congested lines. Then, a novel algorithm is developed to identify a smaller set using two scientific criteria – one is concerned with the absolute impact of generation dispatch decisions, and the other, the relative sensitivities of line flows with respect to the changes of generation outputs. The effectiveness of the proposed algorithm is demonstrated through two simulation studies, one based on IEEE 39-bus for illustration of concepts, and the other based on a large-scale, real-world power system for showing the practical application and significance of results.
Auteurs: Milad Javadi;Mingguo Hong;Ruth N. Angarita;Seyed Hossein Hosseini;John Ning Jiang;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 1772 - 1781
Editeur: IEEE
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» IEEE 1849: The XES Standard: The Second IEEE Standard Sponsored by IEEE Computational Intelligence Society [Society Briefs]
Résumé:
Presents information on the development of IEEE Standard 1849, the XES Standard.
Auteurs: Giovanni Acampora;Autilia Vitiello;Bruno Di Stefano;Wil van der Aalst;Christian Gunther;Eric Verbeek;
Apparue dans: IEEE Computational Intelligence Magazine
Date publication: 05.-2017, volume: 12, issue:2, pages: 4 - 8
Editeur: IEEE
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» IEEE Fellows - Class of 2017 [Society Briefs]
Résumé:
Presents CIS society members who were elevated to the status of IEEE Fellow in 2017.
Auteurs: Gary Yen;
Apparue dans: IEEE Computational Intelligence Magazine
Date publication: 05.-2017, volume: 12, issue:2, pages: 13 - 17
Editeur: IEEE
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» Image Processing With Dipole-Coupled Nanomagnets: Noise Suppression and Edge Enhancement Detection
Résumé:
Hardware-based image processing offers speed and convenience not found in software-centric approaches. Here, we show theoretically that a 2-D periodic array of dipole-coupled elliptical nanomagnets, delineated on a piezoelectric substrate, can act as a dynamical system for specific image processing functions. Each nanomagnet has two stable magnetization states that encode pixel color (black or white). An image containing black and white pixels is first converted to voltage states and then mapped into the magnetization states of a nanomagnet array with magneto-tunneling junctions (MTJs). The same MTJs are employed to read out the processed pixel colors later. Dipole interaction between the nanomagnets implements specific image processing tasks, such as noise reduction and edge enhancement detection. These functions are triggered by applying a global strain to the nanomagnets with a voltage dropped across the piezoelectric substrate. An image containing an arbitrary number of black and white pixels can be processed in few nanoseconds with very low energy cost.
Auteurs: Md Ahsanul Abeed;Ayan Kumar Biswas;Md Mamun Al-Rashid;Jayasimha Atulasimha;Supriyo Bandyopadhyay;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2417 - 2424
Editeur: IEEE
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» Impact of Equivalent Oxide Thickness on Threshold Voltage Variation Induced by Work-Function Variation in Multigate Devices
Résumé:
Using 3-D technology computer aided design simulation, we investigated the impact of equivalent oxide thickness (EOT) on threshold voltage ( ${V}_{{text {TH}}}$ ) variation induced by work-function variation (WFV) in multigate devices. The WFV-induced ${V}_{{text {TH}}}$ variation in multigate devices does not significantly vary with the dielectric constant of the gate dielectric material, but increases with decreasing physical oxide thickness ( ${T}_{{text {OX}}}$ ). As ${T}_{{text {OX}}}$ becomes thinner, electric field tends to be locally concentrated, causing a large variation of electrostatic potential in channel. The slope of the ratio of average grain size to gate area (RGG) plot is observed with various oxide thicknesses. It is confirmed that we can alleviate the WFV-induced ${V}_{{text {TH}}}$ variation without significant performance degradation if gate dielectric layer becomes thicker with appropriately adopted higher-k engineering. In addition, the impact of EOT (including interface layer) on the WFV-induced ${V}_{{text {TH}}}$ variation is studied.
Auteurs: Youngtaek Lee;Changhwan Shin;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2452 - 2456
Editeur: IEEE
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» Impact of Physical Deformation on Electrical Performance of Paper-Based Sensors
Résumé:
We report on investigation of the mechanical properties of paper electronics (printed and made out of paper). One key objective of such paper electronics is to achieve ultraflexibility. Therefore, it is important to understand electrical functionality and reliability of paper electronics under various physical (mechanical) deformations. Here, we show the general mechanical properties of the cellulose paper used and its electrical behavior under applied strain, tackling the main effects that need to be identified when building paper-based systems, from product performance and stability perspective. An overview of the stress–strain behavior of silver ink on paper is discussed, and then, we tackle a more specific analysis of the performance variations of paper sensors made with recyclable household materials when exposed to various mechanical conditions of tensile and compressive bending. This paper is important for developing stable wearable sensors for incorporation into Internet of Everything applications.
Auteurs: Joanna M. Nassar;Muhammad M. Hussain;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2022 - 2029
Editeur: IEEE
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» Impact of Skin-Electrode Capacitance on the Performance of CEMG Biosensor
Résumé:
This letter presents the optimum value of skin-electrode capacitance for a capacitive electromyography (CEMG) biosensor design. Skin-electrode capacitance is proved to be an important variable when defining the input characteristic of a capacitive biosensor by an electrical model of skin–electrode interface. The experimental results show that a CEMG biosensor with the skin-electrode capacitance range of between 255 and 340 pF yields the best performance, low noise, and is small in size.
Auteurs: Charn Loong Ng;Mamun Bin Ibne Reaz;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2636 - 2637
Editeur: IEEE
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» Impedance Nonlinearity Measurement of Interdigital Electrode-Solution System by Free Damped Oscillation
Résumé:
To measure the nonlinear impedance of interdigital electrode-solution system, a novel method based on free damped oscillation is proposed. A high valued active inductance with adjustable negative resistance is constructed by an operational amplifier. A second order oscillation system for measurement is then set up by connecting the active inductance with the device under test. The active inductance is designed to be around 470H to meet the measurement requirements of low frequency. The negative resistor is utilized to adjust damping coefficient of the oscillation system in order to obtain enough number of ring-down oscillation cycles for parameter estimation. The free damped oscillation signal of the oscillation system is obtained under square wave voltage excitation. After processed by Hilbert transform, the instantaneous capacitance and resistance can be calculated simultaneously to implement nonlinear impedance measurement. The operational availability of the proposed method is verified by experimental results of commercial available resistors and capacitors. The impedance nonlinearity of a gold interdigital electrode immersed in KCl solutions of different concentration is tested and compared with that obtained by sweep-amplitude sinusoidal excitation methods. The results indicate that the proposed method can successfully obtain impedance nonlinearity in half of the square wave period.
Auteurs: Deyan Zheng;Yonggui Dong;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2822 - 2830
Editeur: IEEE
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» Impedance-Based Condition Monitoring for Insulation Systems Used in Low-Voltage Electromagnetic Coils
Résumé:
Electromagnetic induction coils are widely used in a variety of applications, many of them safety-critical. The insulation around the wire in an electromagnetic coil accounts for a significant portion of the failures in solenoid-operated valves and in electric motors. This paper presents a method of detecting the degradation of insulation used in low-voltage applications by assessing changes in impedance responses. The results indicate that coil impedance, resolved into resistance and reactance, evolves differently when the coil is subjected to different loading conditions, which reflects insulation degradation signatures due to different failure mechanisms. This method can be used to assess the insulation life of an electromagnetic coil, allowing replacement prior to the formation of harmful shorts or critical coil opens.
Auteurs: Noel Jordan Jameson;Michael H. Azarian;Michael Pecht;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3748 - 3757
Editeur: IEEE
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» Implementation of Locally-Clocked XBM State Machines on FPGAs Using Synchronous CAD Tools
Résumé:
Controllers based on Synchronous Finite State Machines (SFSM) are widely used in the control unit design of complex digital systems. These systems can present serious problems related to the global clock. In this context, the asynchronous paradigm shows interesting features that fit as an alternative for the design, despite of the difficulties of the application of asynchronous logic. An interesting architecture for the Asynchronous Finite State Machines (AFSM) is based on local clock, because it reduces the requirements of asynchronous logic. This manuscript proposes a novel architecture of local clock for AFSMs, which is described by a popular specification known as Extended Burst-Mode (XBM). This architecture presents a better latency time when compared with other local clock architectures. Furthermore, the manuscript proposes a “necessary and sufficient” condition for local clock AFSMs to be synthesized completely on the proposed architecture by using only conventional tools. Through a case study, we present the architecture, its robustness, the synthesis procedure and a comparison with other local clock architectures, highlighting its advantages.
Auteurs: Felipe Tuyama De Faria Barbosa;Duarte Lopes De Oliveira;Tiago S. Curtinhas;Lester de Abreu Faria;Jocemar Francisco De Souza Luciano;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1064 - 1074
Editeur: IEEE
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» Implementations of Coherent Software-Defined Dual-Polarized Radars
Résumé:
Software-defined radio (SDR) platforms represent a compelling solution for low-cost, flexible, dual-polarized radar systems. However, the phase coherency requirements of a dual-polarized radar system between the transmit ports and between the receive ports as well as between transmission and reception, are difficult to attain in popular SDRs. In this paper, we provide high-level overviews of SDR radar systems, dual-polarization radars, and system phase calibration procedures found in literature. The method adopted to achieve coherency involves a manual calibration procedure, which is applied to four dual-polarized radar system configurations designed around commercial off-the-shelf SDR platforms. The implemented, calibrated designs were exercised in a laboratory setting to determine the coherence performance of the SDR-based radar architectures in characterizing a fixed target’s full-polarization scattering matrix.
Auteurs: Jeremy Hershberger;Thomas Pratt;Robert Kossler;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 05.-2017, volume: 65, issue:5, pages: 1673 - 1681
Editeur: IEEE
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» Improved Analytical Model for the Study of Steady State Performance of Droop-Controlled VSC-MTDC Systems
Résumé:
This paper proposes an improved analytical model for the study of steady-state performance of droop-controlled VSC-MTDC systems. When power disturbances occur, such as those imposed by normal changes in power settings and converter outages, the powers of the converters with droop control may hit their limits and hence such converters no longer contribute to power sharing, which should be paid special attention when analyzing the impacts of power disturbances on the performance of multi-terminal HVDC (MTDC) systems. Based on the bisection algorithm and superposition principle, the proposed analytical model provides an easy way to estimate the results of power distributions, dc voltage deviations, and power loss variations of the MTDC system taking converter outage and converter overload into account. Simulations of a modified New England 39-bus system incorporating a four-terminal MTDC system are carried out for validating the proposed analytical model.
Auteurs: Liang Xiao;Zheng Xu;Ting An;Zhipeng Bian;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2083 - 2093
Editeur: IEEE
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» Improved Design and Microfabrication of ${H}$ -Plane and ${E}$ -Plane Loaded Rectangular Slow-Wave Structure for THz TWT Amplifier
Résumé:
This paper reports further investigation on a recently proposed ${H}$ -plane and ${E}$ -plane loaded slow-wave structure (SWS) for terahertz traveling-wave tube (TWT) amplifier. An improved input–output coupler is designed to enable easy fabrication by microfabrication technology, UV-lithography, electroplating, and molding (LIGA), and deep reactive-ion etching. The coupler shows very low reflection coefficient, ${S}_{11} < -15$ dB over a frequency range 360–450 GHz. To improve the beam-wave interaction and enhance the saturated output power of the TWT, the SWS with tapered design is implemented. By tuning the period, the wave is resynchronized with the beam at the end of the SWS, resulting in more than 60% increase in the saturated output power across the 80-GHz bandwidth. In addition, the sensitivity of the output power of the TWT to the fabrication tolerance of the individual geometrical parameters is also studied in detail. It is found that the output power reduces by 80% for approximately 2% variation in the synchronized beam voltage. The KMPR-based UV-LIGA technique is adopted to fabricate the ${H}$ -plane and ${E}$ -plane loaded SWS. The measured lateral dimensional accuracy within $sim 2~mu text{m}$ and rms roughness of metal sidewall surface less than 80 nm is obtained.
Auteurs: Laxma Reddy Billa;Xianbao Shi;Muhammad Nadeem Akram;Xuyuan Chen;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2383 - 2389
Editeur: IEEE
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» Improved Importance Sampling for Reliability Evaluation of Composite Power Systems
Résumé:
This paper presents an improved way of applying Monte Carlo simulation using the crossentropy method to calculate the risk of capacity deficit of a composite power system. By applying importance sampling for load states in addition to the generation and transmission states in a systematic manner, the proposed method is many orders of magnitude more efficient than the crude Monte Carlo simulation and considerably more efficient than other crossentropy-based algorithms that apply other ways of estimating the importance sampling distributions. An effective performance metric of system states is applied in order to find optimal importance sampling distributions during presimulation that significantly reduces the required computational effort. Simulations, using well-known IEEE reliability test systems, show that even problems that are nearly intractable using crude Monte Carlo simulation become very manageable using the proposed method.
Auteurs: Egill Tómasson;Lennart Söder;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2426 - 2434
Editeur: IEEE
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» Improved Power Pulsation Suppression of DFIG for Wind Shear and Tower Shadow Effects
Résumé:
This paper analyzes and simulates wind shear and tower shadow effects in doubly-fed induction generators, which are known to induce a low-frequency oscillation. Such oscillation is called a 3p oscillation, which can cause shaft torsion load aggravation and shaft torque oscillation, it inevitably lead to electromagnetic torque and power fluctuation in the generator and further affect the whole wind power system. By analyzing a two-mass model, it can be known that a flexible drive train has a low-damping characteristic and an amplification of the input of low-frequency wind torque disturbances. Based on this point, this paper presents a new control scheme to restrain 3p oscillation is presented, which is a damping torque observation. A novel torque observer is designed to ascertain the required damping torque. A small-signal model is established for the system and used to analyze the system's static and dynamic characteristics. The effectiveness of the proposed strategy is finally verified by simulation and experimental results.
Auteurs: Zhen Xie;Zhendong Xu;Xing Zhang;Shuying Yang;Lingxiang Wang;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3672 - 3683
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Improved Stability of $alpha $ -InGaZnO Thin-Film Transistor under Positive Gate Bias Stress by Using Fluorine Plasma Treatment
Résumé:
The origin of positive-gate-bias-stress (PGBS)-induced instability and the effects of fluorine treatment on the instability of an InGaZnO thin-film transistor (TFT) are investigated. The fluorine treatments on the dielectric/InGaZnO interface and InGaZnO back channel of the device can effectively modulate their electrical properties. By characterizing the TFTs with various fluorine treatments, it is found that the back channel rather than the dielectric/InGaZnO interface dominates the PGBS instability. Electrons induced by moisture absorption near the back channel migrate from the back channel to the interface under PGBS at room temperature, thus resulting in a threshold-voltage decrease. Moreover, the fluorine treatment on the back channel effectively suppresses the PGBS instability due to reduced moisture absorption caused by the fluorine passivation.
Auteurs: X. D. Huang;J. Q. Song;P. T. Lai;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 576 - 579
Editeur: IEEE
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» Improvement in Sensing Responses to Ammonia Gas for Gas Sensors With Separately Designed Sensing Element Using ALD-Grown ZnO Nanoparticles and Read-Out Element of Top-Gate In-Ga-Zn-O Thin-Film Transistor
Résumé:
Ammonia (NH3) gas sensors with unique oxide semiconductor thin-film transistor (TFT) configuration using ZnO nanoparticles (NPs) as gas-sensing element were fabricated and their gas-sensing responses were evaluated. The ZnO NPs composing the sensing elements were synthesized using atomic layer deposition (ALD). The optimum ALD conditions for the particle-like island-growth of ZnO were established by systematically investigating the ALD temperature and cycle conditions from 140 °C to 160 °C and from 5 to 30, respectively. Controlled devices of the sensor TFTs were prepared with different ALD conditions, in which sensing and read-out elements were designed to be physically separated. This unique device configuration provided us both benefits of improvement in gas-sensing property and stability of the device characteristics. The device showed instant gas responses as well as stable device behaviors at different operating temperature even with repeated gas measurements. Sufficiently good response to NH3 were obtained at 150 °C, which was significantly lower than the operating temperature of previously reported NH3 gas sensors. Based on the results the combination of novel TFT configuration and ALD-prepared ZnO NPs could be an effective method for the improvement in device characteristics of the gas sensors.
Auteurs: Da-Jeong Yun;Gi-Ho Seo;Won-Ho Lee;Sung-Min Yoon;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2350 - 2356
Editeur: IEEE
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» Improvement of the Rain/No-Rain Classification Method for Microwave Radiometers Over the Tibetan Plateau
Résumé:
This letter identifies causes of the deterioration of the Global Satellite Mapping of Precipitation rain detection over the Tibetan Plateau during the summer monsoon season. Using the rain/no-rain classification (RNC) method over the Plateau, observed brightness temperature (Tb) at 21 (23) GHz from the Tropical Rainfall Measuring Mission Microwave Imager (the Defense Meteorological Satellite Program Special Sensor Microwave Imager) [Tb(21 V) and Tb(23 V)], and surface emissivity ( $varepsilon )$ was substituted for surface temperatures (Ts) to exclude areas of low Ts as snow cover because it is difficult to distinguish between the scattering signals of precipitation and snow cover. A case study demonstrates that rain systems are excluded because Ts is often below the threshold for snow cover due to the use of an inadequate value for $varepsilon $ (constant value throughout the year), even though a rain scattering signal at high-frequency channels under no snow cover is evident. After $varepsilon $ is replaced with values from a monthly mean satellite observation-based land surface emissivity database, rainfall detection is improved. In addition, it is suggested that a database of RNCs should also consider diurnal variations in Tb(21 V) and Tb(23 V) due to large diurnal differences over the Plateau.
Auteurs: Munehisa K. Yamamoto;Ippei Tanaka;Shoichi Shige;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 626 - 630
Editeur: IEEE
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» Improving Electrical Safety : Risk Perception and Decision Making in Hazard Analysis
Résumé:
Electricity is unique among energy sources in that its use is virtually ubiquitous in everyday life, yet it also has the potential to be instantly fatal when contacted. Due to its familiarity and commonplace use, people are often complacent about electrical hazards and underestimate the risks associated with exposure to electricity. Many veterans in the electrical industry came of age in an era when best practices for electrical work had not yet been established, and as a result they experienced firsthand the consequences of electrical incidents. Over the past several decades, there has been a movement in the industry to improve safe work practices based on these experiences. This has resulted in great improvements to electrical safety, making electrical incidents not as common. The challenge today is to transfer the knowledge gained from past experience to workers who may not have witnessed serious electrical incidents and, as a result, may fail to recognize the potential for injury associated with electrical work. This article explores how perception of risk affects a worker's decision-making process for recognizing electrical hazards and assessing the likelihood and severity of the associated risks.
Auteurs: Allison Haluik;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 33 - 41
Editeur: IEEE
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» Improving Electrical Safety in the Workplace: Applying Prevention Through Design to Voltage Testing
Résumé:
Fundamental to an electrical safety program is establishing electrically safe work conditions. De-energizing equipment, following adequate lockout/tagout procedures, and verifying the absence of voltage are key to accomplishing this. As industry strives to make the practice of de-energizing equipment before performing electrical work standard practice, verifying the absence of voltage has become one of the most frequent tasks performed by qualified electrical workers.
Auteurs: Rachel M. Bugaris;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 12 - 23
Editeur: IEEE
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» Improving Separability of Structures with Similar Attributes in 2D Transfer Function Design
Résumé:
The 2D transfer function based on scalar value and gradient magnitude (SG-TF) is popularly used in volume rendering. However, it is plagued by the boundary-overlapping problem: different structures with similar attributes have the same region in SG-TF space, and their boundaries are usually connected. The SG-TF thus often fails in separating these structures (or their boundaries) and has limited ability to classify different objects in real-world 3D images. To overcome such a difficulty, we propose a novel method for boundary separation by integrating spatial connectivity computation of the boundaries and set operations on boundary voxels into the SG-TF. Specifically, spatial positions of boundaries and their regions in the SG-TF space are computed, from which boundaries can be well separated and volume rendered in different colors. In the method, the boundaries are divided into three classes and different boundary-separation techniques are applied to them, respectively. The complex task of separating various boundaries in 3D images is then simplified by breaking it into several small separation problems. The method shows good object classification ability in real-world 3D images while avoiding the complexity of high-dimensional transfer functions. Its effectiveness and validation is demonstrated by many experimental results to visualize boundaries of different structures in complex real-world 3D images.
Auteurs: Shouren Lan;Lisheng Wang;Yipeng Song;Yu-ping Wang;Liping Yao;Kun Sun;Bin Xia;Zongben Xu;
Apparue dans: IEEE Transactions on Visualization and Computer Graphics
Date publication: 05.-2017, volume: 23, issue:5, pages: 1546 - 1560
Editeur: IEEE
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» IMS2017 5G Summit, Demo Forum, and Executive Forum
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Debabani Choudhury;Doug Zuckerman;Tim LaRocca;Joy Laskar;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 28 - 31
Editeur: IEEE
Document complet vers site de l'éditeur
 
» IMS2017 Advanced Practice and Industry Paper Competitions
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Steven Rosenau;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 69 - 76
Editeur: IEEE
Document complet vers site de l'éditeur
 
» IMS2017 Awards Banquet
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Peter Staecker;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 104 - 106
Editeur: IEEE
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» IMS2017 Focus and Special Sessions
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Chris Rodenbeck;Y. Ethan Wang;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 34 - 34
Editeur: IEEE
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» IMS2017 Focus Groups
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Ryan Pang;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 73 - 74
Editeur: IEEE
Document complet vers site de l'éditeur
 
» IMS2017 Hackathon: 30-Minute Circuits
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Kelson Lau;Bao Jun Lei;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 84 - 84
Editeur: IEEE
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» IMS2017 Interactive Forum
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: George Zhang;Darcy Bibb;Gui Chao Huang;Ruthsenne Perron;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 36 - 66
Editeur: IEEE
Document complet vers site de l'éditeur
 
» IMS2017 MTT-S Historical Exhibit
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Anthony Combs;Jerry Hausner;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 102 - 106
Editeur: IEEE
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» IMS2017 Panel Sessions
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Charlie Jackson;Reynold Kagiwada;Aaron Oki;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 38 - 40
Editeur: IEEE
Document complet vers site de l'éditeur
 
» IMS2017 Ph.D. Student Sponsorship Initiative
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Rashaunda Henderson;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 92 - 94
Editeur: IEEE
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» IMS2017 Plenary Session
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Victor Lubecke;Debabani Choudhury;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 32 - 40
Editeur: IEEE
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» IMS2017 Project Connect
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Kainalu Matthews;Rhonda Franklin;Rashaunda Henderson;Ryan Pang;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 82 - 83
Editeur: IEEE
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» IMS2017 RF Boot Camp
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Larry Dunleavy;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 67 - 74
Editeur: IEEE
Document complet vers site de l'éditeur
 
» IMS2017 Student Design Competitions
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Xiaomeng Gao;Ashikur Rahman;Peter Orel;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 70 - 71
Editeur: IEEE
Document complet vers site de l'éditeur
 
» IMS2017 Student Paper Competition
Résumé:
Provides a notice of upcoming conference events of interest to practitioners and researchers.
Auteurs: Ryan Gough;
Apparue dans: IEEE Microwave Magazine
Date publication: 05.-2017, volume: 18, issue:3, pages: 72 - 72
Editeur: IEEE
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» In Memoriam: John Staudhammer
Résumé:
John Staudhammer, who died in February 2017, profoundly influenced computer graphics technology and people. His work in computer graphics education and his contributions to the field as a whole significantly impacted the computer graphics technology we now take for granted.
Auteurs: David J. Kasik;
Apparue dans: IEEE Computer Graphics and Applications
Date publication: 05.-2017, volume: 38, issue:3, pages: 14 - 15
Editeur: IEEE
Document complet vers site de l'éditeur
 
» In-Die Through-BEOL Metal Wall for Noise Isolation in 180-nm FD-SOI CMOS
Résumé:
This letter reports a conceptual in-die through-back-end-of-the-line metal wall structure for noise isolation demonstrated in a foundry 180-nm fully depleted silicon-on-insulator (FD-SOI) CMOS technology. The near-closed-loop isolation wall was made of a trench ring etched by focused ion beam and filled with silver nano powder in a post-CMOS process module developed. Crosstalk suppression was confirmed in measurement that shows a reduction of around 9 dBm in the third-order intermodulation interferers as predicted full-wave electromagnetic co-simulation. The structure can be readily integrated into the foundry technologies as a potential crosstalk reduction solution for mixed-signal integrated circuits in FD-SOI CMOS processes.
Auteurs: Fei Lu;Qi Chen;Chenkun Wang;Feilong Zhang;Cheng Li;Rui Ma;X. Shawn Wang;Albert Wang;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 630 - 632
Editeur: IEEE
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» Incentive Pricing Mechanism for Hybrid Access in Femtocell Networks
Résumé:
In this letter, we propose a novel incentive pricing mechanism, where wireless service provider (WSP) offers additional benefits (called bonus) to motivate the adoption of hybrid access in femtocells. The problem is formulated as a two-stage Stackelberg game to reach a win–win situation, where WSP determines the pricing policy as the leader and FOs respond as the followers. The optimal proportion of shared resources for each FO and the optimal pricing factor for WSP are decided independently. Furthermore, a Quality of Service (QoS) based admission control scheme is also designed to admit or reject macro users access. Numerical simulations have been conducted and the results show that the utilities of both WSP and FOs are significantly improved due to the exploitation of incentive pricing mechanism.
Auteurs: Yanjia Qi;Hongyu Wang;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1091 - 1094
Editeur: IEEE
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» Influence Degree Analysis of the Emphases of Education and Training in Virtual Environments dimensional Learning
Résumé:
This work aims to propose a framework with guidelines applicable to three-dimensional learning environments from the usability heuristics appropriate for these systems, in order to evidence the elements that allow to measure an application within the emphasis on education and/or training. The research was carried out based on a systematic review on immersive three dimensional environment heuristics with an emphasis on education and training. Initially, a compilation of research was done through the digital scientific databases. The heuristics will be presented as a statement and will aim to measure the degree of agreement of the interviewees, for which each statement is associated with a Likert scale of frequency of five points. In this way, the present article proposes an evaluation approach that allows to measure elements through heuristics that can be used by several educational professionals. In addition, the present approach allows the reuse of existing systems, evaluating them according to the application emphasis, which enables the adaptation of a three-dimensional virtual learning environment to both educational and training needs.
Auteurs: Adriana Porto Proenca;Milton Miranda Neto;Rodrigo Godoy Domingues;Ludymila Ribeiro Borges;Alexandre Cardoso;Pollyana Notargiacomo;
Apparue dans: IEEE Latin America Transactions
Date publication: 05.-2017, volume: 15, issue:5, pages: 974 - 980
Editeur: IEEE
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» Influence of Rotor Radial Ventilation Ducts Number on Temperature Distribution of Rotor Excitation Winding and Fluid Flow State Between Two Poles of a Fully Air-Cooled Hydro-Generator
Résumé:
With the increase of the capacity of a fully air-cooled hydro-generator, the electromagnetic and thermal designs of such machine face more and more pressure. To ensure the reliability of a large hydro-generator, the thermal issue in rotor should be emphasized. In this paper, the temperature distribution in exciting windings and the fluid flowing between rotor poles are highlighted and investigated. Taking a 250 MW fully air-cooled large hydro-generator as an example, a three-dimensional solid–fluid heat transfer coupling model of the fluid and temperature was established, which includes half-axial rotors, two poles in circumferential direction, and the yoke with four radial ventilation ducts. Via investigating on the loss distribution and the heat transfer condition in the rotor, the fluid and temperature fields of half-axial rotors are calculated by using the conjugated heat transfer method. The obtained results are verified by the measured values. The influences of the velocity and temperature of fluid on its effectiveness of cooling excitation windings, and the relationship between the fluid flow velocity and the heat transferred from outer surface of rotor windings are investigated as well. Similarly, the variations of fluid temperature distribution, the flowing velocity, and the heat transfer coefficient distribution in rotors with two or three ventilation ducts are investigated. The effects of the corresponding velocity and temperature of fluid on temperature distribution within both the windward and leeward side excitation windings are also studied.
Auteurs: Weili Li;Dan Li;Jinyang Li;Xiaochen Zhang;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3767 - 3775
Editeur: IEEE
Document complet vers site de l'éditeur
 
» Initial Beam Association in Millimeter Wave Cellular Systems: Analysis and Design Insights
Résumé:
Enabling the high data rates of millimeter wave (mmWave) cellular systems requires deploying large antenna arrays at both the basestations and mobile users. Prior work on coverage and rate of mmWave cellular networks focused on the case when basestations and mobile beamforming vectors are predesigned for maximum beamforming gains. Designing beamforming/combining vectors, though, requires training, which may impact both the SINR coverage and rate of mmWave systems. This paper evaluates mmWave cellular network performance while accounting for the beam training/association overhead. First, a model for the initial beam association is developed based on beam sweeping and downlink control pilot reuse. To incorporate the impact of beam training, a new metric, called the effective reliable rate, is defined and adopted. Using stochastic geometry, the effective rate of mmWave cellular networks is derived for two special cases: near-orthogonal pilots and full pilot reuse. Analytical and simulation results provide insights into the answers of two important questions. First, what is the impact of beam association on mmWave network performance? Then, should orthogonal or reused pilots be employed? The results show that unless the employed beams are very wide, initial beam training with full pilot reuse is nearly as good as perfect beam alignment.
Auteurs: Ahmed Alkhateeb;Young-Han Nam;Md. Saifur Rahman;Jianzhong Zhang;Robert W. Heath;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 2807 - 2821
Editeur: IEEE
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» Initiator-Integrated 3-D Printing of Magnetic Object for Remote Controlling Application
Résumé:
Magnetically driven micromachines play an essential role in a number of biomedical and other remote control applications. In this paper, a magnetically driven robot composed of customized UV-curable resin was fabricated by (3-D) printing via initiator-triggered radical polymerization and the subsequent polyelectrolyte-brush-assisted electroless plating. A layer of magnetic material was grown in situ on the 3-D printed structure, which exhibited soft-magnetic properties proved by the vibrating sample magnetometer measurement. The magnetic robot was successfully actuated under the rotating magnetic field produced from a manipulator of permanent magnet. By utilizing the spiral structure, the 3-D robot was designed to translate rotational movement into linear motion. A comprehensive investigation was also carried out on the optimization of spiral shape, liquid viscosity and the strategy of magnetic controlling. The remote controlling experiments demonstrate that this initiator-integrated 3-D printing is an effective technique for making magnetically driven objects.
Auteurs: Dongxing Zhang;Junfeng Xiao;Yejun Qiu;Jun Yang;Qiuquan Guo;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 05.-2017, volume: 53, issue:5, pages: 1 - 9
Editeur: IEEE
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» Innovative Mobile Robot Method: Improving the Learning of Programming Languages in Engineering Degrees
Résumé:
This paper describes a study of teaching a programming language in a C programming course by having students assemble and program a low-cost mobile robot. Writing their own programs to define the robot’s behavior raised students’ motivation. Working in small groups, students programmed the robots by using the control structures of structured programming. Over the course, there was a significant improvement in students’ academic performance and motivation. The approach took into account four of the motivational factors that feature in the ARCS model: 1) attention; 2) relevance; 3) confidence; and 4) satisfaction. The main achievements of the approach were to be able to: 1) catch and hold students’ attention throughout the course; 2) increase students’ confidence in the learning process; 3) achieve a high student satisfaction level with their acquired skills; and 4) demonstrate to students the practical usefulness of the knowledge they had learned. This paper also determines the extent to which this strategy was effective in meeting the teaching goals.
Auteurs: Octavio Ortiz Ortiz;Juan Ángel Pastor Franco;Pedro María Alcover Garau;Ruth Herrero Martín;
Apparue dans: IEEE Transactions on Education
Date publication: 05.-2017, volume: 60, issue:2, pages: 143 - 148
Editeur: IEEE
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» Insights Into Interface Treatments in p-Channel Organic Thin-Film Transistors Based on a Novel Molecular Semiconductor
Résumé:
Organic thin-film transistors (OTFTs) were fabricated using a novel small molecule, C6-NTTN, as the semiconductor layer in several different architectures. The C6-NTTN layer was deposited via both vacuum evaporation at different substrate temperatures and via solution-processing, which yield maximum hole mobilities of 0.16 and 0.05 cm2/ ${mathrm{ V}}cdot {mathrm{ s}}$ , respectively. Surface treatments of the substrate, insulator, and metal contacts used for OTFT fabrication employing polymer films and different self-assembled monolayers were investigated. In particular, in bottom-gate devices, the insulator surface hydrophobicity was optimized by the deposition of poly(methyl methacrylate) or hexamethyldisilazane, while in the top-gate geometry, pentafluorobenzenethiol was efficiently used to modify the substrate surface energy and to change the contact work function. Atomic force microscopy analysis was exploited to understand the relationship between the semiconductor thin-film morphology and the device electrical performance. The results shown here indicate an inverse proportionality between the mobility and the interface trap density, with parameters depending especially on semiconductor–insulator interfacial properties, and a correlation between the threshold voltage and the characteristics of the semiconductor–metal interface.
Auteurs: Rosalba Liguori;Hakan Usta;Sandra Fusco;Antonio Facchetti;Gian Domenico Licciardo;Luigi Di Benedetto;Alfredo Rubino;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2338 - 2344
Editeur: IEEE
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» Inspection of Cracks in Aluminum Multilayer Structures Using Planar ECT Probe and Inversion Problem
Résumé:
This paper proposes a method to detect and evaluate surface and subsurface cracks in aluminum multilayer structures using a planar eddy current testing (ECT) probe and processing an inverse problem algorithm. The proposed excitation method using this ECT probe allows the induction of eddy currents with different orientations on the metal surface without rotating the probe during the scan. An inversion algorithm was applied to evaluate the geometry of the cracks. The main result of this inversion algorithm is the determination of the shape of the cracks using the reconstructed eddy current pattern inside the specimen. These reconstructed patterns give the indication of the length, orientation, and geometry profile of the crack. In this paper, complex geometry cracks at different depths are inspected. Experimental data were obtained around a star crack at different depths in a stack of four aluminum plates where each plate has a thickness equal to 1 mm. The presented work shows that the distance between the sensor and the layer under analysis must be adjusted in the inversion process in order to obtain the best reconstructed images when subsurface cracks are under study. This consideration affects the quality of the resulting images.
Auteurs: Dario Jerónimo Pasadas;Artur Lopes Ribeiro;Helena Geirinhas Ramos;Tiago Jorge Rocha;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 920 - 927
Editeur: IEEE
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» Instantaneous Feedback Control for a Fuel-Prioritized Vehicle Cruising System on Highways With a Varying Slope
Résumé:
This paper presents two fuel-prioritized feedback controllers, which are called the estimated minimum principle (EMP) and kinetic energy conversion (KEC), to realize eco-cruising on varying slopes for vehicles with conventional powertrains. The former is derived from the minimum principle with an estimated Hamiltonian, and the latter is designed based on the equivalent conversion between the kinetic-energy change of vehicle body and the fuel consumption of the engine. They are implemented with analytical control laws and rely on current road slope information only without look-ahead prediction. This feature results in a very light computing load, with the average computing time of each step less than one millisecond. Their fuel-saving performances are quantitatively studied and compared with a model predictive control and a constant speed control. As an expansion, the control rule for avoiding rear-end collision is also designed by using a safety-guaranteed car-following model to constrain the high-risk behaviors.
Auteurs: Shaobing Xu;Shengbo Eben Li;Bo Cheng;Keqiang Li;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 05.-2017, volume: 18, issue:5, pages: 1210 - 1220
Editeur: IEEE
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» Instantaneous Power Quality Indices Based on Single-Sideband Modulation and Wavelet Packet-Hilbert Transform
Résumé:
Diverse conditions in power systems, such as massive use of nonlinear loads, continuous switching and operation of large electrical loads, and the integration of renewable energies, among others, have adversely affected the power quality (PQ) because they produce undesirable distortions in the waveforms of voltage and current. The conventional way to quantify the PQ is using the PQ indices (PQIs). Yet, the nonstationary properties of voltage and current signals degrade the PQIs estimation whenever classical techniques are used. In this paper, a methodology based on single-sideband modulation method and the Wavelet and Hilbert transforms for the estimation of instantaneous PQIs is proposed. It is shown that the proposal yields better tracking of transitory changes in the voltage/current signals than classical techniques such as the short-time Fourier transform. The PQIs used are the root-mean-square values, frequency, total harmonic distortion, active power, reactive power, apparent power, distortion power, power factor, and total power factor. PQIs performance is validated using synthetic and real signals.
Auteurs: Ismael Urbina-Salas;Jose R. Razo-Hernandez;David Granados-Lieberman;Martin Valtierra-Rodriguez;Jose E. Torres-Fernandez;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 1021 - 1031
Editeur: IEEE
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» Insulated Bus Bars in Low-Voltage Systems: Reducing Arc Duration and Energy Emissions
Résumé:
Power distribution equipment is the backbone of any industrial process infrastructure. Safety and reliability are the two most important criteria in the proper functioning of the power distribution system. Low-voltage switchgear (LVS) is an important part of power distribution. Minimizing arc faults in the switchgear is a matter of utmost concern to maintain a safe environment. Arc-resistant LVS is designed to provide an additional degree of protection for operating personnel performing normal duties near the equipment. In this article, we report a series of arc-flash simulations performed on an arc-resistant LVS in both bare bus (noninsulated) and insulated or isolated bus configurations. In all simulations, the insulated or isolated bus had a significantly shorter arc duration and lower energy emissions.
Auteurs: Rahul Rajvanshi;Tom Hawkins;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 48 - 53
Editeur: IEEE
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» Integrated Safety Management: Creating an All-Inclusive Electrical Safety Program
Résumé:
Electrical safety is imperative for kee ping workers safe, and a safety management system is a means to implement it. The safety management system known as Integrated Safety Management (ISM) is a formal and proven system for the safe execution of work activities. The ISM system can be incorporated into a work-control process and structure an electrical safety program through its guiding principles and core functions. An electrical safety work-control process has two components that need to be implemented for success: a National Fire Protection Association (NFPA) 70E-based electrical safety program and an ISM-based work-control process. An electrical safety program that implements the seven guiding principles and five core functions listed in Table 1 gives a well-defined and document-supported process to keep workers safe.
Auteurs: Robert Joseph Spang;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 64 - 70
Editeur: IEEE
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» Integrated Virtual Impactor Enabled PM2.5 Sensor
Résumé:
As more and more proofs show that fine particles (diameter of $2.5~mu text{m}$ and below) pose more risk on human health than coarse particles, an increasing need for monitoring fine particles has emerged. A miniaturized sensor designed for measuring fine particle concentration is presented in this paper. The proposed sensor possesses a compact size of only 15 mm $times10$ mm $times1$ mm. A virtual impactor has been integrated as a particle size selector and the design is optimized by simulation-assisted analysis. The sensor is realized by silicon microfabrication and wafer-level packaging. Testing results show that a high measurement accuracy of $2.55~mu text{g}/text{m}^{3}$ has been achieved.
Auteurs: Mingzhi Dong;Elina Iervolino;Fabio Santagata;Guoyi Zhang;Guoqi Zhang;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2814 - 2821
Editeur: IEEE
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» Integrating Collaborative and Live Coding for Distance Education
Résumé:
What does an online programming course need to engage students and improve their skills? To answer this question, the authors designed and tested a feature-rich collaborative environment for an online class and found that it enhanced learning through methods such as remote pair programming, live coding, and a tight code-to-artifact feedback loop.
Auteurs: Soroush Ghorashi;Carlos Jensen;
Apparue dans: Computer
Date publication: 05.-2017, volume: 50, issue:5, pages: 27 - 35
Editeur: IEEE
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» Integration of Ant Colony Optimization and Object-Based Analysis for LiDAR Data Classification
Résumé:
Light detection and ranging (LiDAR) data classification provides useful thematic maps for numerous geospatial applications. Several methods and algorithms have been proposed recently for LiDAR data classification. Most studies focused on object-based analysis because of its advantages over per-pixel-based methods. However, several issues, such as parameter optimization, attribute selection, and development of transferable rulesets, remain challenging in this topic. This study contributes to LiDAR data classification by developing an approach that integrates ant colony optimization (ACO) and rule-based classification. First, LiDAR-derived digital elevation and digital surface models were integrated with high-resolution orthophotos. Second, the processed raster was segmented with the multiresolution segmentation method. Subsequently, the parameters were optimized with a supervised technique based on fuzzy analysis. A total of 20 attributes were selected based on general knowledge on the study area and LiDAR data; the best subset containing 12 attributes was then selected via ACO. These attributes were utilized to develop rulesets through the use of a decision tree algorithm, and a thematic map was generated for the study area. Results revealed the robustness of the proposed method, which has an overall accuracy of ∼95% and a kappa coefficient of 0.94. The rule-based approach with all attributes and the k nearest neighbor (KNN) classification method were applied to validate the results of the proposed method. The overall accuracy of the rule-based method with all attributes was ∼88% (kappa = 0.82), whereas the KNN method had an overall accuracy of <70% and produced a poor thematic map. The selection of the ACO algorithm was justified through a comparison with three well-known feature selection methods. On the oth- r hand, the transferability of the developed rules was evaluated by using a second LiDAR dataset at another study area. The overall accuracy and the kappa index for the second study area were 92% and 0.90, respectively. Overall, the findings indicate that the selection of a subset with significant attributes is important for accurate LiDAR data classification with object-based methods.
Auteurs: Maher Ibrahim Sameen;Biswajeet Pradhan;Helmi Z. M. Shafri;Mustafa Ridha Mezaal;Hussain bin Hamid;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 05.-2017, volume: 10, issue:5, pages: 2055 - 2066
Editeur: IEEE
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» Intelligent Charge Rate Optimization of PHEVs Incorporating Driver Satisfaction and Grid Constraints
Résumé:
In this paper, an optimization model is developed to find a plug-in hybrid electric vehicle (PHEV) optimum charging rate profile that dynamically varies throughout the day. From the grid point of view, the model takes into account the constraints of maximum demand and charging facilities, while from the driver’s point of view, waiting and charging time restrictions are considered. The novelty of this paper lies in maximizing the energy delivered to PHEVs in a region equipped with smart grid technology by intelligently alternating charging rates during the day while incorporating both driver satisfaction constraints as well as grid limitations. Using the proposed optimization model, two cases with optimized charging rates are studied and compared with constant charging levels. Furthermore, quantitative results from the perspective of both power grid contribution and driver satisfaction are presented and discussed in detail for each case.
Auteurs: Zahra Darabi;Poria Fajri;Mehdi Ferdowsi;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 05.-2017, volume: 18, issue:5, pages: 1325 - 1332
Editeur: IEEE
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» Interactive Evolution Strategies for Minimizing Single-objective Functions
Résumé:
This article discusses issues related to the application of the user interactivity in optimization process, aided by the method of the Evolution Strategies, with the objective of improve the minimization process of the evaluated functions, both in their response and in the time of obtaining, through the intervention of the user. Its development is based on the methodology of the Evolution Strategies, characterized by the concept of natural selection. However, the minimization process requires an intervention in the stagnations of local minima to get a better efficiency. To increase the applicability of the approached methodology, it is proposed the use of the user interactivity in minimization process, allowing the manipulation of mutation rate and recombination, activation of the mutation of self-adaptive parameters as well as monitoring the whole process. The proposed methodology was used in the evaluation of test functions for optimization, as well as in the evaluation of a real case.
Auteurs: Luiz Henrique Reis Jesus;Leonardo Cunha Brito;
Apparue dans: IEEE Latin America Transactions
Date publication: 05.-2017, volume: 15, issue:5, pages: 981 - 987
Editeur: IEEE
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» Interactive Satellite Image Change Detection With Context-Aware Canonical Correlation Analysis
Résumé:
Automatic change detection is one of the remote sensing applications that has received an increasing attention during the last years. However, fully automatic solutions reach their limitation; on the one hand, it is difficult to design general decision criteria able to select area of changes for images under various acquisition conditions, and on the other hand, the relevance of changes may differ from one user to another. In this letter, we introduce an alternative change detection method based on relevance feedback. The proposed algorithm is iterative and based on a query and answer model that: 1) asks the user questions about the relevance of his targeted changes and 2) according to these answers, updates change detection results. Our method is also based on a new formulation of canonical correlation analysis (CCA), referred to as context-aware CCA, that learns transformations, which map data from different input spaces (related to multitemporal satellite images) into a common latent space, which is sensitive to relevant changes while being resilient to irrelevant ones. These CCA transformations correspond to the optimum of a particular constrained maximization problem that mixes an alignment term with a context-based regularization criterion. The particularity of this novel CCA approach resides in its ability to exploit spatial geometric context resulting into better performances compared with other CCA approaches, as shown in experiments.
Auteurs: Hichem Sahbi;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 607 - 611
Editeur: IEEE
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» Interdisciplinary Education for Design Innovation
Résumé:
A design education program must unite traditionally siloed disciplines, spanning rigid academic boundaries from engineering to social sciences. Work to establish the Kyoto University Design School had to meet these challenges in promoting interdisciplinary cooperation and provides a solid model for others to build on. The web extra at https://youtu.be/bTWoIew-lpg features interviews and further details about Kyoto University Design School's innovative curriculum.
Auteurs: Toru Ishida;Tetsuo Sawaragi;Kumiyo Nakakoji;Takushi Sogo;
Apparue dans: Computer
Date publication: 05.-2017, volume: 50, issue:5, pages: 44 - 52
Editeur: IEEE
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» Interferometry With ALOS-2 Full-Aperture ScanSAR Data
Résumé:
Advanced Land Observing Satellite-2 (ALOS-2) is designed to routinely acquire both scanning synthetic aperture radar (ScanSAR) and stripmap data. In this paper, we present a special multiband bandpass filter (MBF) to remove azimuth nonoverlap spectra for the interferometric processing of ALOS-2 full-aperture ScanSAR product. As required by the MBF, we estimate the important ScanSAR system parameters and the start times of raw bursts using ALOS-2 full-aperture ScanSAR image. The resulting MBF can remove the nonoverlap spectra caused by both Doppler centroid frequency difference and burst misalignment. It can be used in ScanSAR-ScanSAR interferometry, as well as ScanSAR-stripmap interferometry. Based on the MBF, we propose a single processing workflow that is able to implement both ScanSAR-ScanSAR interferometry and ScanSAR-stripmap interferometry. Finally, we present example interferograms of the 2015 Gorkha earthquake in Nepal processed using the proposed processing workflow. The interferograms are greatly improved after applying the MBF to remove the significant amount of nonoverlap spectra in the data.
Auteurs: Cunren Liang;Eric J. Fielding;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 05.-2017, volume: 55, issue:5, pages: 2739 - 2750
Editeur: IEEE
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» Interlocking Patent Rights and Value Appropriation: Insights From the Razor Industry
Résumé:
This paper analyzes a duopoly-like situation in the wet shaving industry featuring an innovation leader and a follower. In this, the leader claims to have filed “interlocking” patents. The explorative case study examines how the leader filed said patents and how their structures have affected potential value appropriation. In fact, the market leader has claimed technical elements in multiple patents, while the patents themselves do not legally overlap. This analysis will also cover triggers and boundary conditions that facilitate or limit such claim compositions. Finally, the market leader has seemingly been able to successfully appropriate value from its strategy. This study will contribute to the literature on value appropriation, the interplay between corporate engineering and intellectual property functions, as well as the economics literature on patent thickets.
Auteurs: Christian Sternitzke;
Apparue dans: IEEE Transactions on Engineering Management
Date publication: 05.-2017, volume: 64, issue:2, pages: 249 - 265
Editeur: IEEE
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» Internet of Education Resources Using a Chemistry-Inspired Framework
Résumé:
Open education resources (OERs) are public domain learning objects used extensively in both online and traditional education settings. To facilitate the use of OERs, a novel chemistry-inspired framework links learning objects to help the education community contribute, augment, and locate these valuable resources.
Auteurs: Henry C.B. Chan;
Apparue dans: Computer
Date publication: 05.-2017, volume: 50, issue:5, pages: 54 - 60
Editeur: IEEE
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» Interpolation of Ewald-Accelerated Periodic Green’s Function Representations for Homogeneous or Layered Media
Résumé:
A method is explored and developed for significantly accelerating the computation of the Ewald series representation for periodic homogeneous media Green’s functions. The method involves extracting corner singularity terms from the corners of the unit cell, resulting in a smooth regularized Green’s function that is amenable to interpolation. The approach can be used to accelerate layered-media problems, where application of Kummer’s method splits the spectral (Floquet modal) series representation into a rapidly converging difference series that is regular plus a residual series that contains any spatial singularities present. The residual series corresponds to a homogeneous medium, and can thus be treated with the method proposed here.
Auteurs: Ferhat Turker Celepcikay;Donald R. Wilton;David R. Jackson;William A. Johnson;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2517 - 2525
Editeur: IEEE
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» Intrinsic Interference Based Physical Layer Encryption for OFDM/OQAM
Résumé:
A physical layer encryption method is proposed for orthogonal frequency division multiplexing with offset quadrature amplitude modulation. The proposed method uses intentionally added pure imaginary symbols as keys, so that their intrinsic interferences can obfuscate true data symbols at the eavesdroppers. The key generation method and four loading patterns are proposed. Also, the impact of channel estimation error, the robustness against ciphertext attacks, and the information leakage at the eavesdropper are analyzed. Finally, the performance of the proposed method is evaluated through numerical simulations.
Auteurs: Manabu Sakai;Hai Lin;Katsumi Yamashita;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1059 - 1062
Editeur: IEEE
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» Introduction to the Special Section on the 2016 Radio Frequency Integrated Circuits (RFIC) Symposium
Résumé:
This issue of the IEEE Journal of Solid-State Circuits includes a selection of papers presented at last year’s Radio-Frequency Integrated Circuits (RFIC) Symposium, highlighting some of the main advances in radio-frequency integrated circuit design. The RFIC Symposium, which is part of the IEEE MTT-S Microwave Week, is considered the premier conference for publishing advances in the area of wireless IC design. The focus areas of last year’s meeting, held in San Francisco, CA, USA, cover a broad range of topics from 5G millimeter-wave-integrated systems to low-power wireless sensors, from spectrum sensing to mixed-signal power amplifiers, from terahertz to baseband circuits.
Auteurs: Danilo Manstretta;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 05.-2017, volume: 52, issue:5, pages: 1183 - 1184
Editeur: IEEE
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» Intrusion Detection and Ejection Framework Against Lethal Attacks in UAV-Aided Networks: A Bayesian Game-Theoretic Methodology
Résumé:
Advances in wireless communications and microelectronics have spearheaded the development of unmanned aerial vehicles (UAVs), which can be used to augment a ground network composed of sensors and/or vehicles in order to increase coverage, enhance the end-to-end delay, and improve data processing. While UAV-aided networks can potentially find applications in many areas, a number of issues, particularly security, have not been readily addressed. The intrusion detection system is the most commonly used technique to detect attackers. In this paper, we focus on addressing two main issues within the context of intrusion detection and attacker ejection in UAV-aided networks, namely, activation of the intrusion monitoring process and attacker ejection. In fact, when a large number of nodes activate their monitoring processes, the incurred overhead can be substantial and, as a consequence, degrades the network performance. Therefore, a tradeoff between the intrusion detection rate and overhead is considered in this work. It is not always the best strategy to eject a node immediately when it exhibits a bad sign of malicious activities since this sign could be provisional (the node may switch to a normal behavior in the future) or be simply due to noise or unreliable communications. Thus, a dilemma between detection and false positive rates is taken into account in this paper. We propose to address these two security issues by a Bayesian game model in order to accurately detect attacks (i.e., high detection and low false positive rates) with a low overhead. Simulation results have demonstrated that our proposed security game framework does achieve reliable detection.
Auteurs: Hichem Sedjelmaci;Sidi Mohammed Senouci;Nirwan Ansari;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 05.-2017, volume: 18, issue:5, pages: 1143 - 1153
Editeur: IEEE
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» Invasion of the hardware snatchers
Résumé:
In February 2014, the FBI charged a Florida man, Marc Heera, with selling a cloned version of the Hondata s300, a plug-in module for the engine computer that reads data from sensors in Honda cars and automatically adjusts the air-fuel mixture, idle speed, and other factors to improve performance. The plug-in also allows users to monitor the engine via Bluetooth and make their own adjustments. The clones certainly looked like the genuine product, but in fact they contained circuit boards that had likely been built in China, according to designs Heera had obtained through reverse engineering. Honda warned that cars using the counterfeits exhibited a number of problems, including random limits on engine rpm and, occasionally, failure to start. Devices that connect to an engine control unit (ECU) present particular safety concerns; researchers have demonstrated that, through ECU access, they could hijack a car's brakes and steering.
Auteurs: Mark M. Tehranipoor;Ujjwal Guin;Swarup Bhunia;
Apparue dans: IEEE Spectrum
Date publication: 05.-2017, volume: 54, issue:5, pages: 36 - 41
Editeur: IEEE
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» Inverse Profiling of Inhomogeneous Subsurface Targets With Arbitrary Cross Sections Using Covariance Matrix Adaptation Evolution Strategy
Résumé:
The problem of subsurface inverse profiling of a 2-D inhomogeneous buried dielectric target is addressed in this letter. An iterative optimization technique is proposed that utilizes Covariance Matrix Adaption Evolutionary Strategy (CMA-ES) as its inverse solver and Method of Moments, using Conjugate Gradient-fast Fourier transform, as the forward solver. The numerical results indicate that CMA-ES, as its first reported implementation in buried target reconstruction, can successfully be applied to this challenging reconstruction problem. Also, comparison with Evolutionary Programming and Particle Swarm Optimization indicates that CMA-ES can significantly outperform the other two-optimization techniques in the inhomogeneous subsurface imaging. In addition, examples of various scenarios involving noisy data, lossy targets and multiple targets further demonstrate that CMA-ES can be considered as a robust, simple, and efficient optimization tool in the reconstruction of complex buried targets.
Auteurs: Maryam Hajebi;Ahmad Hoorfar;Elie Bou-Daher;Ahad Tavakoli;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 612 - 616
Editeur: IEEE
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» Investigation of a Hump Phenomenon in Back-Channel-Etched Amorphous In-Ga-Zn-O Thin-Film Transistors Under Negative Bias Stress
Résumé:
The hump phenomenon along with a negative shift of threshold voltage emerging in the transfer characteristics of amorphous InGaZnO thin-film transistors under negative bias stress was investigated. Higher measurement temperature and larger bias voltage can induce more and faster hole injection, thus leading to the increased parasitic ON-state current and more negative shift of the threshold voltage. Nevertheless, the parasitic current is independent of the channel width, illustrating that the parasitic channel originates from the hole trapping near the IGZO edges along the channel length. Integrated Systems Engineering Technology Computer-aided Design simulation confirms that the electric field near the IGZO edge is relatively dense, and the direction is more conducive for the holes in IGZO to inject into passivation (PV), to gate insulator (GI), or at PV/GI interface.
Auteurs: Jianwen Yang;Po-Yung Liao;Ting-Chang Chang;Bo-Wei Chen;Hui-Chun Huang;Hsiao-Cheng Chiang;Wan-Ching Su;Qun Zhang;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 592 - 595
Editeur: IEEE
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» Investigation of a Nonlinear Energy Harvester
Résumé:
The use of nonlinear architectures for energy harvesting can significantly improve the efficiency of the conversion mechanism, as respect to the use of linear devices, especially when the mechanical energy is distributed over a wide frequency bandwidth. This is the case of energy harvesting form wideband vibrations. In this paper, performances of a piezoelectric energy harvester exploiting a snap-through buckling configuration are investigated. The device is supposed to switch between its stable states, where two piezoelectric transducers are positioned to implement the mechanical-to-electric conversion mechanism. A simple theoretical two-state model of the device is presented along with a complete experimental characterization aimed at investigating the mechanical and electrical behaviors of the device. The device is demonstrated to be capable of scavenging energy from vibration sources in the range 0.5–5 Hz, but could be exploited up to 15 Hz with an acceptable loss of efficiency. The bandwidth of the device is compatible with applications where the vibrations occur at low frequencies, e.g., in the case of a running human. In this paper, we demonstrate the viability of our setup for harvesting energy from mechanical vibrations. The device is seen to generate power up to 155~\mu text{W} at 5 Hz; the power is sufficient to operate a standard wireless sensor node. The conversion efficiency of the harvester in the range 0.5–5 Hz is from 13% up to 18% with an average of 15%.
Auteurs: Bruno Andò;Salvatore Baglio;Adi R. Bulsara;Vincenzo Marletta;Antonio Pistorio;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 1067 - 1075
Editeur: IEEE
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» Investigation of Infrared Photo-Detection Through Subgap Density-of-States in a-InGaZnO Thin-Film Transistors
Résumé:
Amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) are investigated for a possible application to infrared (IR) photodetector through subgap density-of-states over the forbidden bandgap. The origin of the sub-bandgap( ${h}nu < {E} _{g})$ photo-response in a-IGZO TFTs is due to optically pumped electrons from the photo-responsive subgap states ( ${E} _{C}$ - ${E} _{textit {ph}}{<}{E}_{t}{<}{E}_{F})$ . Among the sub-bandgap lights, we investigate the reproducible IR photo-response in a-IGZO TFTs as a photodetector without the persistent photoconductivity (PPC) effect. In this letter, we characterize the IR photo-response mechanism through various optical and electrical measurements on the wavelength, optical power, bias-modulated quasi-Fermi level, and photo-responsive states. This result is expected to provide independent and/or integrated IR detector with transparent substrate combined with a-IGZO TFTs.
Auteurs: Heesung Lee;Junyeap Kim;Jaewon Kim;Seong Kwang Kim;Yongwoo Lee;Jae-Young Kim;Jun Tae Jang;Jaewon Park;Sung-Jin Choi;Dae Hwan Kim;Dong Myong Kim;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 584 - 587
Editeur: IEEE
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» Investigation of Mo/Ti/AlN/HfO2 High-k Metal Gate Stack for Low Power Consumption InGaAs NMOS Device Application
Résumé:
Use of the Mo/Ti/AlN/HfO2 metal/dielectric stack to increase the permittivity of HfO2 for low power consumption InGaAs-based MOSFET is investigated in this letter. The dielectric constant of HfO2 was found to increase by 47%, from 17 to 25, after Ti doping without affecting the interface trap density around the mid-gap of the MOSCAPs. A strong inversion behavior with low leakage current for the MOSCAP was also observed. The gate voltage needed to tune the Fermi level of InGaAs channel was found to be smaller for the Ti-doped HfO2 sample as compared with the sample with un-doped HfO2. The increase of the dielectric constant of HfO2 after Ti doping combined with the use of Ti gate metal, which has the work function level near the conduction band edge of InGaAs, makes the proposed Mo/Ti/HfO2 (Ti) stack ideal for future lowpower consumption InGaAs-based NMOS applications.
Auteurs: Huy Binh Do;Quang Ho Luc;Minh Thien Huu Ha;Sa Hoang Huynh;Tuan Anh Nguyen;Chenming Hu;Yueh Chin Lin;Edward Yi Chang;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 552 - 555
Editeur: IEEE
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» Investigation of Time-Domain Locus of SiGe HBTs in the Avalanche Region by Using the X-Parameter Measurement Under Large-Signal Drive
Résumé:
In this letter, the high-frequency avalanche effects of silicon germanium (SiGe) heterojunction bipolar transistors (HBTs) on time-domain locus characteristics based on the X-parameter measurement are presented and analyzed by applying the concept of the dead space theory for the first time. The measured X-parameters of the SiGe HBTs are utilized to obtain the time-domain waveform under large-signal drive in the impact ionization region. Input locus of the SiGe HBTs operating in the avalanche regime presents negative slope when compared with the positive slope in the active region. The rotation direction of the transfer locus at breakdown is also investigated.
Auteurs: Chie-In Lee;Yan-Ting Lin;Wei-Cheng Lin;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 05.-2017, volume: 27, issue:5, pages: 464 - 466
Editeur: IEEE
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» Irradiation of Radiation-Tolerant Single-Mode Optical Fibers at Cryogenic Temperature
Résumé:
Radiation effects at cryogenic temperature are investigated in two radiation-tolerant Fluorine-doped single-mode fibers originating from two different manufacturers. This paper presents measurements at room temperature (297 K) and at cryogenic temperature (16 K) of the radiation induced attenuation at 1312 nm and 1570 nm for both fibers. In addition to the massive increase of the optical attenuation at 16 K, the fiber is found to be in a frozen state where thermal bleaching and defect recombination no longer occurs. However, a long-term recovery, including the heating of the fiber from cryogenic temperature to room temperature, anneals a large amount of the defects created and brings the fiber back to almost its initial performance.
Auteurs: Jeremy Blanc;Daniel Ricci;Jochen Kuhnhenn;Udo Weinand;Olaf J. Schumann;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1929 - 1935
Editeur: IEEE
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» Is Being Flexible Advantageous for Demands?
Résumé:
This paper analyzes the impacts of flexible demands on day-ahead market outcomes in a system with significant wind power production. We use a two-stage stochastic market-clearing model, where the first stage represents the day-ahead market and the second stage represents the real-time operation. On one hand, flexibility of demands is beneficial to the system as a whole since such flexibility reduces the operation cost, but on the other hand, shifts in demands from peak periods to off-peak periods may influence prices in such a way that demands may not be willing to provide flexibility. Specifically, we investigate the impacts of different degree of demand flexibility on day-ahead prices. A number of scenarios modeling the uncertainty associated with wind production at the operation stage, and nonconvexities due to start-up costs of generators and their minimum power outputs are taken into account.
Auteurs: Farzaneh Abbaspourtorbati;Antonio J. Conejo;Jianhui Wang;Rachid Cherkaoui;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2337 - 2345
Editeur: IEEE
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» Is the Sequence of SuperAlarm Triggers More Predictive Than Sequence of the Currently Utilized Patient Monitor Alarms?
Résumé:
Objective: Our previous studies have shown that “code blue” events can be predicted by SuperAlarm patterns that are multivariate combinations of monitor alarms and laboratory test results cooccurring frequently preceding the events but rarely among control patients. Deploying these patterns to the monitor data streams can generate SuperAlarm sequences. The objective of this study is to test the hypothesis that SuperAlarm sequences may contain more predictive sequential patterns than monitor alarms sequences. Methods: Monitor alarms and laboratory test results are extracted from a total of 254 adult coded and 2213 control patients. The training dataset is composed of subsequences that are sampled from complete sequences and then further represented as fixed-dimensional vectors by the term frequency inverse document frequency method. The information gain technique and weighted support vector machine are adopted to select the most relevant features and train a classifier to differentiate sequences between coded patients and control patients. Performances are assessed based on an independent dataset using three metrics: sensitivity of lead time (Sen$^L$ @T), alarm frequency reduction rate (AFRR), and work-up to detection ratio (WDR). Results: The performance of 12-h-long sequences of SuperAlarm can yield a Sen $^L$@2 of 93.33%, an AFRR of 87.28%, and a WDR of 3.01. At an AFRR = 87.28%, Sen$^L$@2 for raw alarm sequences and discretized alarm sequences are 73.33% and 70.19%, respectively. At a WDR = 3.01, Sen$^L$@2 are 49.88% and 43.33%. Conclusion and Significance: The results demonstra- e that SuperAlarm sequences indeed outperform monitor alarm sequences and suggest that one can focus on sequential patterns from SuperAlarm sequences to develop more precise patient monitoring solutions.
Auteurs: Yong Bai;Duc Do;Quan Ding;Jorge Arroyo Palacios;Yalda Shahriari;Michele M. Pelter;Noel Boyle;Richard Fidler;Xiao Hu;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 05.-2017, volume: 64, issue:5, pages: 1023 - 1032
Editeur: IEEE
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» Iterative Reweighting Heterogeneous Transfer Learning Framework for Supervised Remote Sensing Image Classification
Résumé:
Supervised classification methods have been widely used in the hyperspectral remote sensing image analysis. However, they require a large number of training samples to guarantee good performance, which costs a large amount of time and human labor, motivating researchers to reuse labeled samples from the mass of pre-existing related images. Transfer learning methods can adapt knowledge in the existing images to solve the classification problem in new yet related images, and have drawn increasing interest in the remote sensing field. However, the existing methods in the RS field require that all the images share the same dimensionality, which prevents their practical application. This paper focuses on the transfer learning problem for heterogeneous spaces where the dimensions are different. We propose a novel iterative reweighting heterogeneous transfer learning (IRHTL) framework that iteratively learns a common space for the source and target data and conducts a novel iterative reweighting strategy to reweight the source samples. In each iteration, the heterogeneous data are first mapped into a common space by two projection functions based on a weighted support vector machine. Second, based on the common subspace, the source data are reweighted by using the iterative reweighting strategy and reused for the transferring, according to their relative importance. Experiments undertaken on three data sets confirmed the effectiveness and reliability of the proposed IRHTL method.
Auteurs: Xue Li;Liangpei Zhang;Bo Du;Lefei Zhang;Qian Shi;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 05.-2017, volume: 10, issue:5, pages: 2022 - 2035
Editeur: IEEE
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» Itinerant Routing in Elastic Optical Networks
Résumé:
We state a new problem of itinerant routing in elastic optical networks, which we define as the establishment and reconfiguration of an itinerant connection. In an itinerant connection, one of the connection end nodes is allowed to change. Itinerant routing could also be considered a form of connection restoration, where a connection has to be restored to a different end node. With the introduction and growth of mobile-network services and content-oriented services, and the eventual deployment of elastic optical networks, there is a need to support this itinerant routing in the elastic optical networks. We present and discuss two major use cases of the itinerant routing, and propose a novel reconfiguration algorithm. Our algorithm does not deteriorate the network performance, and requires half as many new links to configure in comparison with the complete shortest-path reconfiguration algorithm. The performance evaluation was carried out with 46 800 simulation runs using randomly-generated realistic transport networks.
Auteurs: Ireneusz Szcześniak;Artur Gola;Andrzej Jajszczyk;Andrzej R. Pach;Bożena Woźna-Szcześniak;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1868 - 1875
Editeur: IEEE
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» Joint Assignment of Power, Routing, and Spectrum in Static Flexible-Grid Networks
Résumé:
This paper proposes a novel network planning strategy to jointly allocate physical layer resources together with the routing and spectrum assignment in transparent nonlinear flexible-grid optical networks with static traffic demands. The physical layer resources, such as power spectral density, modulation format, and carrier frequency, are optimized for each connection. By linearizing the Gaussian noise model, both an optimal formulation and a low complexity decomposition heuristic are proposed. Our methods minimize the spectrum usage of networks, while satisfying requirements on the throughput and quality of transmission. Compared with existing schemes that allocate a uniform power spectral density to all connections, our proposed methods relax this constraint and, thus, utilize network resources more efficiently. Numerical results show that by optimizing the power spectral density per connection, the spectrum usage can be reduced by around ${text{20}}%$ over uniform power spectral density schemes.
Auteurs: Li Yan;Erik Agrell;Madushanka Nishan Dharmaweera;Henk Wymeersch;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1766 - 1774
Editeur: IEEE
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» Joint Compression of Near-Duplicate Videos
Résumé:
The expanding social network and multimedia technologies encourage more and more people to store and transmit information in visual format, such as image and video. However, the cost of this convenience brings about a shock to traditional video severs and exposes them under the risk of overloading. In the huge volume of online videos, there are a large amount of near-duplicate videos (NDVs). Although quite a number of research work have been proposed to detect NDVs, little research effort is made to compress these NDVs in a more effective manner than independent video compression. In this study, we make an in-depth exploration of the data redundancy of NDVs and propose a video analysis and coding framework to jointly compress NDVs. In order to employ the proposed NDV analysis and coding framework, a graph-based similar video grouping method and a number of preprocessing functions are designed to explore the correlation of visual information among NDVs and thus suit the requirement of joint video coding. Experimental results verify that the proposed NDV analysis and coding framework is able to effectively compress NDVs and thus save video data storage.
Auteurs: Hanli Wang;Tao Tian;Ming Ma;Jun Wu;
Apparue dans: IEEE Transactions on Multimedia
Date publication: 05.-2017, volume: 19, issue:5, pages: 908 - 920
Editeur: IEEE
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» Joint Device Positioning and Clock Synchronization in 5G Ultra-Dense Networks
Résumé:
In this paper, we address the prospects and key enabling technologies for highly efficient and accurate device positioning and tracking in fifth generation (5G) radio access networks. Building on the premises of ultra-dense networks as well as on the adoption of multicarrier waveforms and antenna arrays in the access nodes (ANs), we first formulate extended Kalman filter (EKF)-based solutions for computationally efficient joint estimation and tracking of the time of arrival (ToA) and direction of arrival (DoA) of the user nodes (UNs) using uplink reference signals. Then, a second EKF stage is proposed in order to fuse the individual DoA and ToA estimates from one or several ANs into a UN position estimate. Since all the processing takes place at the network side, the computing complexity and energy consumption at the UN side are kept to a minimum. The cascaded EKFs proposed in this article also take into account the unavoidable relative clock offsets between UNs and ANs, such that reliable clock synchronization of the access-link is obtained as a valuable by-product. The proposed cascaded EKF scheme is then revised and extended to more general and challenging scenarios where not only the UNs have clock offsets against the network time, but also the ANs themselves are not mutually synchronized in time. Finally, comprehensive performance evaluations of the proposed solutions on a realistic 5G network setup, building on the METIS project based outdoor Madrid map model together with complete ray tracing based propagation modeling, are provided. The obtained results clearly demonstrate that by using the developed methods, sub-meter scale positioning and tracking accuracy of moving devices is indeed technically feasible in future 5G radio access networks operating at sub-6 GHz frequencies, despite the realistic assumptions related to clock offsets and potentially even under unsynchronized network elements.
Auteurs: Mike Koivisto;Mário Costa;Janis Werner;Kari Heiska;Jukka Talvitie;Kari Leppänen;Visa Koivunen;Mikko Valkama;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 2866 - 2881
Editeur: IEEE
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» Joint Dimming and Communication Design for Visible Light Communication
Résumé:
Multi-pulse position modulation (M-PPM) is advantageous in a visible light communication system due to its overall satisfactory performance in spectrum efficiency and dimming control. In this letter, we consider the joint dimming and communication design with M-PPM. We provide a model for the dimming control and address the balance between the dimming loss minimization and the transmission rate maximization. The dimming loss is modeled by the quantization loss within the dimming range for the discrete transmission power levels. The transmission rate is evaluated by the channel capacity. We propose two optimization formulations on the dimming requirement service and the transmission rate maximization. Numerical results show that the objective loss function may increase as either the lower limit of the dimming range approaches zero or the upper limit approaches the peak transmission power.
Auteurs: Shun Lou;Chen Gong;Nan Wu;Zhengyuan Xu;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1043 - 1046
Editeur: IEEE
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» Joint Precoding and RRH Selection for User-Centric Green MIMO C-RAN
Résumé:
This paper jointly optimizes the precoding matrices and the set of active remote radio heads (RRHs) to minimize the network power consumption for a user-centric cloud radio access network, where both the RRHs and users have multiple antennas and each user is served by its nearby RRHs. Both users’ rate requirements and per-RRH power constraints are considered. Due to these conflicting constraints, this optimization problem may be infeasible. In this paper, we propose to solve this problem in two stages. In Stage I, a low-complexity user selection algorithm is proposed to find the largest subset of feasible users. In Stage II, a low-complexity algorithm is proposed to solve the optimization problem with the users selected from Stage I. Specifically, the re-weighted $l_{1}$ -norm minimization method is used to transform the original problem with non-smooth objective function into a series of weighted power minimization (WPM) problems, each of which can be solved by the weighted minimum mean square error (WMMSE) method. The solution obtained by the WMMSE method is proved to satisfy the Karush-Kuhn-Tucker conditions of the WPM problem. Moreover, a low-complexity algorithm based on Newton’s method and the gradient descent method is developed to update the precoder matrices in each iteration of the WMMSE method. Simulation results demonstrate the rapid convergence of the proposed algorithms and the benefits of equipping multiple antennas at the user side. Moreover, the proposed algorithm is shown to achieve near-optimal performance in terms of NPC.
Auteurs: Cunhua Pan;Huiling Zhu;Nathan J. Gomes;Jiangzhou Wang;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 2891 - 2906
Editeur: IEEE
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» Joint Symbol and Chip Synchronization for a Burst-Mode-Communication Superregenerative MSK Receiver
Résumé:
In this paper we describe a superregenerative (SR) MSK receiver able to operate in a burst-mode framework where synchronization is required for each packet. The receiver is based on an SR oscillator which provides samples of the incoming instantaneous phase trajectories. We develop a simple yet effective technique to achieve joint chip and symbol synchronization within the time limits of a suitable preamble. We develop some general results and focus on the case of the IEEE 802.15.4 MSK physical layer. We provide details on a VHDL implementation on an FPGA where the most complex digital processing block is an accumulator. Simulation and experimental results are provided to validate the described technique.
Auteurs: Alexis López-Riera;Francisco del Águila-López;Pere Palá-Schönwälder;Jordi Bonet-Dalmau;Rosa Giralt-Mas;F. Xavier Moncunill-Geniz;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 05.-2017, volume: 64, issue:5, pages: 1260 - 1269
Editeur: IEEE
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» Joint Transceiver and Offset Design for Visible Light Communications With Input-Dependent Shot Noise
Résumé:
In this paper, we investigate the problem of the joint transceiver and offset design for point-to-point multiple-input–multiple-output (MIMO) and multiple user multiple-input–single-output visible light communication (VLC) systems. Both uplink and downlink multi-user scenarios are considered. The shot noise induced by the incoming signals is considered, leading to a more realistic MIMO VLC channel model. Under key lighting constraints, we formulate non-convex optimization problems aimed at minimizing the sum mean squared error. To optimize the transceiver and the offset jointly, a gradient projection-based procedure is resorted to. When only imperfect channel state information is available, a semidefinite programming-based scheme is proposed to obtain robust transceiver and offset. The proposed method is shown to non-trivially outperform the conventional scaled zero forcing and singular. value decomposition-based equalization methods. The robust scheme works particularly well when the signal is much stronger than the noise.
Auteurs: Qian Gao;Chen Gong;Zhengyuan Xu;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 2736 - 2747
Editeur: IEEE
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» JPSS-1VIIRS Prelaunch Polarization Testing and Performance
Résumé:
The Visible Infrared Imaging Radiometer Suite (VIIRS) instruments onboard both the Suomi National Polar-orbiting Partnership (S-NPP) and the first Joint Polar Satellite System (JPSS-1) spacecraft, with launch dates of October 2011 and late 2016, respectively, have polarization sensitivity, which affects the at-aperture radiometric calibration. This polarization sensitivity is caused by optics within VIIRS having different reflectance and transmission values as a function of at-aperture photon electric field orientation and is spectrally, spatially, and scan angle dependent. Characterization of the instrument's polarization sensitivity for each visible near-infrared (VNIR) band and detector was performed prelaunch at multiple cross-track scan angles. The resultant characterization parameters are VIIRS polarization amplitude and phase that enable the at-aperture radiance to be adjusted based on its polarization characteristics. The sensor requirements are that the polarization amplitude for scan angles within ±45° of nadir be below 2.5%-3% depending on the band and have an uncertainty in both amplitude and phase of less than 0.5%. The S-NPP VIIRS passed these requirements with band M1 (412 nm) having the smallest margin (~8%). Modification to the VNIR bandpass filter designs on JPSS-1 was performed to reduce out-of-band response leaks observed prelaunch on S-NPP. An unintended consequence of the spectral bandpass modification was an increase in the polarization sensitivity by roughly a factor of 2 for some VNIR bands. The degree to which JPSS-1 VIIRS polarization sensitivity characterization results exceed the sensor specifications and comparisons with S-NPP will be discussed.
Auteurs: David Moyer;Jeff McIntire;James Young;James K. McCarthy;Eugene Waluschka;Xiaoxiong Xiong;Frank J. De Luccia;
Apparue dans: IEEE Transactions on Geoscience and Remote Sensing
Date publication: 05.-2017, volume: 55, issue:5, pages: 2463 - 2476
Editeur: IEEE
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» Kernel Fused Representation-Based Classifier for Hyperspectral Imagery
Résumé:
In this letter, we propose a kernel fused representation-based classifier (KFRC) for hyperspectral images (HSIs), which combines sparse representation (SR) and collaborative representation (CR) into a unified kernel representation-based classification framework. First, we present two individual kernel methods, i.e., kernel SR (KSR) and kernel CR (KCR), which kernelize the representation methods by projecting the samples into a high-dimensional kernel space to improve the samples separability between different classes. Once obtaining the two kernel representation coefficients, KFRC attempts to achieve a balance between KSR and KCR via an adjusting parameter $theta $ in the kernel residual domain. Subsequently, the class label of each test sample is determined by the minimum residual for each class. Experimental results on two HSIs demonstrate the proposed kernel fused method performs better than the other state-of-the-art representation-based classifiers.
Auteurs: Le Gan;Peijun Du;Junshi Xia;Yaping Meng;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 684 - 688
Editeur: IEEE
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» Knowledge Base Semantic Integration Using Crowdsourcing
Résumé:
The semantic Web has enabled the creation of a growing number of knowledge bases (KBs), which are designed independently using different techniques. Integration of KBs has attracted much attention as different KBs usually contain overlapping and complementary information. Automatic techniques for KB integration have been improved but far from perfect. Therefore, in this paper, we study the problem of knowledge base semantic integration using crowd intelligence. There are both classes and instances in a KB, in our work, we propose a novel hybrid framework for KB semantic integration considering the semantic heterogeneity of KB class structures. We first perform semantic integration of the class structures via crowdsourcing, then apply the blocking-based instance matching approach according to the integrated class structure. For class structure (taxonomy) semantic integration, the crowd is leveraged to help identifying the semantic relationships between classes to handle the semantic heterogeneity problem. Under the conditions of both large scale KBs and limited monetary budget for crowdsourcing, we formalize the class structure (taxonomy) semantic integration problem as a Local Tree Based Query Selection (LTQS) problem. We show that the LTQS problem is NP-hard and propose two greedy-based algorithms, i.e., static query selection and adaptive query selection. Furthermore, the KBs are usually of large scales and have millions of instances, direct pairwise-based instance matching is inefficient. Therefore, we adopt the blockingbased strategy for instance matching, taking advantage of the class structure (taxonomy) integration result. The experiments on real large scale KBs verify the effectiveness and efficiency of the proposed approaches.
Auteurs: Rui Meng;Lei Chen;Yongxin Tong;Chen Zhang;
Apparue dans: IEEE Transactions on Knowledge and Data Engineering
Date publication: 05.-2017, volume: 29, issue:5, pages: 1087 - 1100
Editeur: IEEE
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» Land Contamination Analysis of SMOS Brightness Temperature Error Near Coastal Areas
Résumé:
For Soil Moisture And Ocean Salinity (SMOS) data, significant errors exist near coastal areas because of the contamination by the nearby land. For analyzing the origin of the land contamination, in this letter, it is found, from the global map of SMOS data error, that although the SMOS data error due to land contamination near coasts varies in different regions, the characteristic that the error increases significantly in proximity to land is similar in global scope. The detailed analysis of SMOS brightness temperature (TB) error in the selected area reveals a decreasing trend with the increase of the distance to coast (DC). An SMOS TB measurement model according to geophysical parameters of the selected area and SMOS/microwave imaging radiometer aperture synthesis antenna array is established to analyze the origin of the TB error variation due to land contamination. The simulation results, which agree with the SMOS TB data analysis, show that within 40 km of DC, TB error is large and decreases sharply from ~60 to ~4 K with the increase of DC, since the mainlobe of the antenna array is departing from land to ocean; during 40–400 km of DC, TB error decreases smoothly from ~4 to ~0.15 K, since the lower near sidelobes are observing and leaving land; TB error slightly decreases to 0 from 400 to 800 km when the lower far sidelobes leave land. The study of the origin of land contamination on ocean TB will be helpful for improving the observation of salinity near coastal areas.
Auteurs: Yan Li;Qingxia Li;Hailiang Lu;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 587 - 591
Editeur: IEEE
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» Land-Use Classification via Extreme Learning Classifier Based on Deep Convolutional Features
Résumé:
One of the challenging issues in high-resolution remote sensing images is classifying land-use scenes with high quality and accuracy. An effective feature extractor and classifier can boost classification accuracy in scene classification. This letter proposes a deep-learning-based classification method, which combines convolutional neural networks (CNNs) and extreme learning machine (ELM) to improve classification performance. A pretrained CNN is initially used to learn deep and robust features. However, the generalization ability is finite and suboptimal, because the traditional CNN adopts fully connected layers as classifier. We use an ELM classifier with the CNN-learned features instead of the fully connected layers of CNN to obtain excellent results. The effectiveness of the proposed method is tested on the UC-Merced data set that has 2100 remotely sensed land-use-scene images with 21 categories. Experimental results show that the proposed CNN-ELM classification method achieves satisfactory results.
Auteurs: Qian Weng;Zhengyuan Mao;Jiawen Lin;Wenzhong Guo;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 704 - 708
Editeur: IEEE
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» Lane Change Maneuvers for Automated Vehicles
Résumé:
By considering a lane change maneuver as primarily a longitudinal motion planning problem, this paper presents a lane change maneuver algorithm with a pragmatic approach to determine an inter-vehicle traffic gap and time instance to perform the maneuver. The proposed approach selects an appropriate inter-vehicle traffic gap and time instance to perform the lane change maneuver by simply estimating whether there might exist a longitudinal trajectory that allows the automated vehicle to safely perform the maneuver. The lane change maneuver algorithm then proceeds to solve two loosely coupled convex quadratic programs to obtain the longitudinal trajectory to position the automated vehicle in the selected inter-vehicle traffic gap at the desired time instance and the corresponding lateral trajectory. Simulation results demonstrate the capability of the proposed approach to select an appropriate inter-vehicle traffic gap and time instance to initialize the lateral motion of a lane change maneuver in various traffic scenarios. The real-time ability of the lane change maneuver algorithm to generate safe and smooth trajectories is shown by experimental results of a Volvo V60 performing automated lane change maneuvers on a test track.
Auteurs: Julia Nilsson;Mattias Brännström;Erik Coelingh;Jonas Fredriksson;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 05.-2017, volume: 18, issue:5, pages: 1087 - 1096
Editeur: IEEE
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» Large-Scale Smart Grids: Recipes for Successful Integrations [From the Editor]
Résumé:
Presents the introductory editorial for this issue of the publication.
Auteurs: Michael Henderson;
Apparue dans: IEEE Power and Energy Magazine
Date publication: 05.-2017, volume: 15, issue:3, pages: 4 - 6
Editeur: IEEE
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» Large-Scale VM Placement with Disk Anti-Colocation Constraints Using Hierarchical Decomposition and Mixed Integer Programming
Résumé:
As computational clouds offer increasingly sophisticated services, there is a dramatic increase in the variety and complexity of virtual machine (VM) placement problems. In this paper, we consider a VM placement problem with a special type of anti-colocation requirements—disk anti-colocation—which stipulate that, for every VM assigned to a PM (physical machine), its virtual disks should be spread out across the physical disks of the PM. Once such a requirement is met, the users of the VM can expect improved disk I/O performance. There will also be improvement in fault tolerance and availability. For scalable solutions, we propose a method that combines hierarchical decomposition with mixed integer programming (MIP), where the basic building blocks are independent, small MIP subproblems. We provide experimental results to demonstrate the effectiveness of the proposed method. We show that it is scalable and achieves high performance with respect to the optimization objective.
Auteurs: Ye Xia;Mauricio Tsugawa;Jose A. B. Fortes;Shigang Chen;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 05.-2017, volume: 28, issue:5, pages: 1361 - 1374
Editeur: IEEE
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» Laser Diode Current Driver With $(1-t/T)^{-1}$ Time Dependence in 0.35- $mutext{m}$ BiCMOS Technology for Quantum Random Number Generators
Résumé:
A laser diode current driver with $(1-t/T)^{-1}$ time dependence in 0.35- $mutext{m}$ BiCMOS technology is presented in this brief. It is intended for application in optical quantum random number generators. The current driver is based on the balanced type of a bipolar junction transistor translinear loop with a sawtooth current as one of its inputs. The controllability of the frequency, shape, amplitude, and dc level of the current pulses is provided. The achievable frequency bandwidth of the current pulses is up to 100 MHz. A relative error of the measured waveform at a frequency of 25 MHz is smaller than 3% in 97.4% of the time period of interest.
Auteurs: Nikša Tadić;Bernhard Goll;Horst Zimmermann;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 510 - 514
Editeur: IEEE
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» Laser-Assisted Counter-Facing Plasma Focus Device as a Light Source for EUV Lithography
Résumé:
A pair of plasma focus devices was operated with a counter-facing configuration. The focus electrode consisted of six cathodes and a center anode, drove a multichannel discharge. The $2 times 6$ multichannel discharges were triggered by a YAG laser, which also supplied lithium plasma as the radiation source. A high energy density lithium plasma was formed in the center of focus electrodes, which emitted radiation in an extreme ultraviolet region through the Lyman- $alpha $ (2p-1s) transition of hydrogenlike lithium ions for pulse duration of more than microsecond. A proof of principle experiment and the latest advances toward realization of a high-average power system are shown.
Auteurs: Tatsuya Sodekoda;Shintaro Kurata;Hajime Kuwabara;Tomoaki Kawasaki;Shotaro Kittaka;Kazuhiko Horioka;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 05.-2017, volume: 45, issue:5, pages: 836 - 842
Editeur: IEEE
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» Lasing Polarization Characteristics in 1.55- $mu text{m}$ Spin-Injected VCSELs
Résumé:
Circular polarization characteristics in vertical-cavity surface-emitting lasers (VCSELs) with InAlGaAs quantum wells injected by spin-polarized electrons were investigated. A degree of circular polarization of 10% was obtained in a reduced birefringence VCSEL at a lasing wavelength of 1544 nm at room temperature under optical pumping of spin-polarized electrons. Strong birefringence originally introduced to stabilize the lasing polarization was confirmed to be undesirable for a high degree of circular polarization in spin-injected VCSELs. A spin-flip rate equation analysis fairly reproduced the experimental results and supported our conclusions.
Auteurs: Nobuhide Yokota;Ryutaro Takeuchi;Hiroshi Yasaka;Kazuhiro Ikeda;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 05.-2017, volume: 29, issue:9, pages: 711 - 714
Editeur: IEEE
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» Leader-Follower Synchronization of Euler-Lagrange Systems With Time-Varying Leader Trajectory and Constrained Discrete-Time Communication
Résumé:
This paper addresses the leader-follower synchronization problem of uncertain networked Euler-Lagrange systems under directed interconnection graphs in the presence of communication constraints. We present an adaptive distributed control algorithm such that a group of Euler-Lagrange systems asymptotically synchronize their states to those of a dynamic leader with a time-varying trajectory. The information exchange between all systems in the network is assumed to be discrete in time, intermittent, and subject to irregular communication delays and possible packets dropouts. It is shown that leader-follower synchronization is reached for arbitrary characteristics of the communication process provided that the directed interconnection graph contains a spanning tree. Simulation results are given to illustrate the effectiveness of the proposed control scheme.
Auteurs: Abdelkader Abdessameud;Abdelhamid Tayebi;Ilia G. Polushin;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2539 - 2545
Editeur: IEEE
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» Leaky-Wave Antenna Array With a Power-Recycling Feeding Network for Radiation Efficiency Improvement
Résumé:
A novel kind of leaky-wave antenna (LWA) array with a power-recycling feeding network is proposed for radiation efficiency improvement. The antenna array is constructed by two kinds of substrate-integrated waveguide LWAs with different periodic slots. One kind of the LWA is designed to work on the fundamental ( $m=0$ ) wave and radiates in the forward direction. The other one is designed to work on the −1th ( $m = -1$ ) spatial harmonic and radiates in the backward direction. The nonradiated power at the end of one kind of the LWA is directly fed into the other (adjacent) kind of the LWA in reverse direction. Therefore, the reversed feeding can compensate the opposite radiation direction of the two kinds of LWAs, and result in a superposition of radiation. So, both the gain and radiation efficiency of the antenna can be significantly improved, while the array maintains a compact size as those of traditional planar arrays. Simulation results are compared with measurement results to validate the proposed concept of integrating different leaky-wave structures into one array.
Auteurs: Yunjie Geng;Junhong Wang;Yujian Li;Zheng Li;Meie Chen;Zhan Zhang;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2689 - 2694
Editeur: IEEE
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» Learning Hierarchical Decision Trees for Single-Image Super-Resolution
Résumé:
Sparse representation has been extensively studied for image super-resolution (SR), and it achieved great improvement. Deep-learning-based SR methods have also emerged in the literature to pursue better SR results. In this paper, we propose to use a set of decision tree strategies for fast and high-quality image SR. Our proposed SR using decision tree (SRDT) method takes the divide-and-conquer strategy, which performs a few simple binary tests to classify an input low-resolution (LR) patch into one of the leaf nodes and directly multiplies this LR patch with the regression model at that leaf node for regression. Both the classification process and the regression process take an extremely small amount of computation. To further boost the SR results, we introduce a SR using hierarchical decision trees (SRHDT) method, which cascades multiple layers of decision trees for SR and progressively refines the estimated high-resolution image. Inspired by the random forests approach, which combines regression models from an ensemble of decision trees, we propose to fuse regression models from relevant leaf nodes within the same decision tree to form a more robust approach. The SRHDT method with fused regression model (SRHDT_f) improves further the SRHDT method by 0.1-dB in PNSR. Our experimental results show that our initial approach, the SRDT method, achieves SR results comparable to those of the sparse-representation-based method and the deep-learning-based method, but our method is much faster. Furthermore, our enhanced version, the SRHDT_f method, achieves more than 0.3-dB higher PSNR than that of the A+ method, which is the state-of-the-art method in SR.
Auteurs: Jun-Jie Huang;Wan-Chi Siu;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 05.-2017, volume: 27, issue:5, pages: 937 - 950
Editeur: IEEE
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» Learning Immune-Defectives Graph Through Group Tests
Résumé:
This paper deals with an abstraction of a unified problem of drug discovery and pathogen identification. Pathogen identification involves the identification of disease-causing biomolecules. Drug discovery involves finding chemical compounds, called lead compounds, that bind to pathogenic proteins and eventually inhibit the function of the protein. In this paper, the lead compounds are abstracted as inhibitors, pathogenic proteins as defectives, and the mixture of “ineffective” chemical compounds and non-pathogenic proteins as normal items. A defective could be immune to the presence of an inhibitor in a test. So, a test containing a defective is positive if it does not contain its “associated” inhibitor. The goal of this paper is to identify the defectives, inhibitors, and their “associations” with high probability, or in other words, learn the immune defectives graph (IDG) efficiently through group tests. We propose a probabilistic non-adaptive pooling design, a probabilistic two-stage adaptive pooling design, and decoding algorithms for learning the IDG. For the two-stage adaptive-pooling design, we show that the sample complexity of the number of tests required to guarantee recovery of the inhibitors, defectives, and their associations with high probability, i.e., the upper bound, exceeds the proposed lower bound by a logarithmic multiplicative factor in the number of items. To be precise, lower and upper bounds of $Omega ((r+d)log n + rd)$ and $O(rd log n)$ tests, respectively, are identified for classifying $r$ inhibitors and $d$ defectives amongst $n$ items, and identifying their associations. For the non-adaptive pooling design, we show that the upper bound (given by $O((r+d)^{2} log n)$ tests) exceeds the proposed lower bound (given by $max {Omega ((r+d)log n + rd),Omega (({r^{2}}/{log r})log n),Omega (d^{2})}$ tests) by at most a logarithmic multiplicative factor in the number of items.
Auteurs: Abhinav Ganesan;Sidharth Jaggi;Venkatesh Saligrama;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 05.-2017, volume: 63, issue:5, pages: 3010 - 3028
Editeur: IEEE
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» Learning on Big Graph: Label Inference and Regularization with Anchor Hierarchy
Résumé:
Several models have been proposed to cope with the rapidly increasing size of data, such as Anchor Graph Regularization (AGR). The AGR approach significantly accelerates graph-based learning by exploring a set of anchors. However, when a dataset becomes much larger, AGR still faces a big graph which brings dramatically increasing computational costs. To overcome this issue, we propose a novel Hierarchical Anchor Graph Regularization (HAGR) approach by exploring multiple-layer anchors with a pyramid-style structure. In HAGR, the labels of datapoints are inferred from the coarsest anchors layer by layer in a coarse-to-fine manner. The label smoothness regularization is performed on all datapoints, and we demonstrate that the optimization process only involves a small-size reduced Laplacian matrix. We also introduce a fast approach to construct our hierarchical anchor graph based on an approximate nearest neighbor search technique. Experiments on million-scale datasets demonstrate the effectiveness and efficiency of the proposed HAGR approach over existing methods. Results show that the HAGR approach is even able to achieve a good performance within 3 minutes in an 8-million-example classification task.
Auteurs: Meng Wang;Weijie Fu;Shijie Hao;Hengchang Liu;Xindong Wu;
Apparue dans: IEEE Transactions on Knowledge and Data Engineering
Date publication: 05.-2017, volume: 29, issue:5, pages: 1101 - 1114
Editeur: IEEE
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» Learning to Predict High-Quality Edge Maps for Room Layout Estimation
Résumé:
The goal of room layout estimation is to predict the three-dimensional box that represents the room spatial structure from a monocular image. In this paper, a deconvolution network is trained first to predict the edge map of a room image. Compared to the previous fully convolutional networks, the proposed deconvolution network has a multilayer deconvolution process that can refine the edge map estimate layer by layer. The deconvolution network also has fully connected layers to aggregate the information of every region throughout the entire image. During the layout generation process, an adaptive sampling strategy is introduced based on the obtained high-quality edge maps. Experimental results prove that the learned edge maps are highly reliable and can produce accurate layouts of room images.
Auteurs: Weidong Zhang;Wei Zhang;Kan Liu;Jason Gu;
Apparue dans: IEEE Transactions on Multimedia
Date publication: 05.-2017, volume: 19, issue:5, pages: 935 - 943
Editeur: IEEE
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» Leveraging Game Theory to Achieve Efficient Attack-Aware Service Provisioning in EONs
Résumé:
Multidomain elastic optical networks (MD-EONs) help to improve network scalability, extend service coverage, and facilitate good interoperability to orchestrate administrative domains managed by different carriers. Since the users in other domains can launch cross-domain physical-layer attacks to a domain, this paper studies the problem of attack-aware service provisioning in one domain of an MD-EON. We consider a realistic scenario that does not treat all the interdomain lightpaths as malicious ones, and try to arrange the lightpaths’ routing and spectrum assignment (RSA) schemes with the help of the game theory to balance the spectrum utilization and security-level of the domain well. Specifically, we define a two-player Bayesian game to represent the provisioning procedure for each interdomain request, and design the game strategies and utility functions for the players (i.e., the domain manager and the user from other domains). Then, we formulate a nonlinear programming model, solve the game with it to obtain a Bayesian Nash equilibrium (BNE), and determine the best strategies for the players based on the BNE. Finally, with the game model, we propose a game-assisted RSA algorithm to achieve attack-aware service provisioning efficiently. The proposed algorithm is evaluated with extensive simulations and the results confirm its effectiveness.
Auteurs: Jing Zhu;Bin Zhao;Zuqing Zhu;
Apparue dans: Journal of Lightwave Technology
Date publication: 05.-2017, volume: 35, issue:10, pages: 1785 - 1796
Editeur: IEEE
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» LiDAR Data Classification Using Extinction Profiles and a Composite Kernel Support Vector Machine
Résumé:
This letter proposes a novel framework for the classification of light detection and ranging (LiDAR)-derived features. In this context, several features are extracted directly from the LiDAR point cloud data using aggregated local point neighborhoods, including laser echo ratio, variance of point elevation, plane fitting residuals, and echo intensity. Additionally, the LiDAR digital surface model (DSM) is input to our classification. Thus, both the LiDAR raster DSM and also rich geometric and also backscatter 3-D point cloud information aggregated to images are considered in our workflow. These extracted features are characterized as base images to be fed to extinction profiles to model spatial and contextual information. Then, a composite kernel support vector machine is investigated to efficiently integrate the elevation and spatial information suitable for the LiDAR data. Results indicate that the proposed method can obtain high classification accuracy using LiDAR data alone (e.g., more than 86% overall accuracy on the benchmark Houston LiDAR data using the standard set of training and test samples on all 15 classes) in a short CPU processing time.
Auteurs: Pedram Ghamisi;Bernhard Höfle;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 05.-2017, volume: 14, issue:5, pages: 659 - 663
Editeur: IEEE
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» Light-Emitting Illumination and Field Emission Device of Potassium Hydroxide-Doped Electrochemically Reduced Graphene Oxide
Résumé:
This paper presents a parallel plate-type field emission device of potassium hydroxide-doped electrochemically reduced graphene oxide (GO) manufactured using highly oriented pyrolytic graphite through electrochemical exfoliation. The material properties of the GO were tested through Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The optimal electron emission characteristics of the device were as follows: turn-on field = 2.03 V/ $mu text{m}$ , field emission current $= ,, 16.4~mu text{A}$ , and field emission enhancement factor = 8377. At an emission peak wavelength of 563.7 nm, the optimal device had a light flux of 4.21 lumens and an illumination of 140.3 lux. These properties can be utilized in various optoelectronic devices, such as nanoelectronics devices, sensors, electrochemical systems, and energy storage devices.
Auteurs: Ching-Tsang Chang;Yi-Tsung Chang;Yun-Jhong Chih;Yu-Hao Lee;Chun-Hu Chen;Lung-Chien Chen;Jau-Je Wu;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 2251 - 2256
Editeur: IEEE
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» Lighting Matters in Industrial Environments: A Framework Linking Workplace Safety to Lighting Quality Metrics
Résumé:
Lighting affects human performance and, therefore, safety in industrial environments. Recent developments in light-emitting diode (LED) lighting technology offer an opportunity for a scientific evaluation of the quality of light in industrial spaces. For this article, the possibility of reducing the risk of key causes of occupational hazards through the effective application of lighting was evaluated. Vision science research was reviewed to identify mechanisms that could improve object detection, supra threshold visual performance, and response time. Metrics to quantify these mechanisms-i.e., small target visibility (STV), relative visual performance (RVP), mesopic luminance, and luminaire system application efficacy (LSAE)-were reviewed and applied in the context of industrial lighting installations. The results indicated the potential to harness new lighting technology to enhance visual task performance and thereby improve safety and productivity. Lighting is also related to the fatigue of industrial workers. It could influence fatigue by degrading the sleep quality of night-shift workers, causing visual discomfort and creating a negative perception of the environment. A review of research, simulations, and calculations led the authors to develop a framework that links occupational injury incidents to lighting quality metrics for industrial environments. This framework needs to be validated using field studies that are designed based on this research. In this period of technological transition, facility managers can use this study to benchmark lighting technologies and installations for safety. This article presents value propositions that a versatile and controllable source such as LEDs could offer to industries.
Auteurs: Asiri Jayawardena;David Duffy;Joseph M. Manahan;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 54 - 63
Editeur: IEEE
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» Line-of-Sight Millimeter-Wave Communications Using Orbital Angular Momentum Multiplexing Combined With Conventional Spatial Multiplexing
Résumé:
Line-of-sight wireless communications can benefit from the simultaneous transmission of multiple independent data streams through the same medium in order to increase system capacity. A common approach is to use conventional spatial multiplexing with spatially separated transmitter/receiver antennae, for which inter-channel crosstalk is reduced by employing multiple-input-multiple-output (MIMO) signal processing at the receivers. Another fairly recent approach to transmitting multiple data streams is to use orbital-angular-momentum (OAM) multiplexing, which employs the orthogonality among OAM beams to minimize inter-channel crosstalk and enable efficient (de)multiplexing. In this paper, we explore the potential of utilizing both of these multiplexing techniques to provide system design flexibility and performance enhancement. We demonstrate a 16 Gbit/s millimeter-wave link using OAM multiplexing combined with conventional spatial multiplexing over a short link distance of 1.8 meters (shorter than Rayleigh distance). Specifically, we implement a spatial multiplexing system with a $2times 2$ antenna aperture architecture, in which each transmitter aperture contains two multiplexed 4 Gbit/s data-carrying OAM beams. A MIMO-based signal processing is used at the receiver to mitigate channel interference. Our experimental results show performance improvements for all channels after MIMO processing, with bit-error rates of each channel below the forward error correction limit of $3.8times 10^{-3}$ . We also simulate the capacity for both the $4times 4$ MIMO system and the $2times 2$ MIMO with OAM multiplexing. Our work indicates that OAM multiplexing and conventional spatial multipl- xing can be simultaneously utilized to provide design flexibility. The combination of these two approaches can potentially enhance system capacity given a fixed aperture area of the transmitter/receiver (when the link distance is within a few Rayleigh distances).
Auteurs: Yongxiong Ren;Long Li;Guodong Xie;Yan Yan;Yinwen Cao;Hao Huang;Nisar Ahmed;Zhe Zhao;Peicheng Liao;Chongfu Zhang;Giuseppe Caire;Andreas F. Molisch;Moshe Tur;Alan E. Willner;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3151 - 3161
Editeur: IEEE
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» Linear Diversity Combining on Correlated and Unequal Power Nakagami-0.5 Fading Channels
Résumé:
Closed-form or analytical solutions for the outage probability and average probability of symbol error are derived for correlated (and independent), unequal power dual branch Nakagami-0.5 linear diversity combining schemes. A novel analytical solution for the probability density function of the sum of two correlated, dissimilar Nakagami-0.5 random variables is derived.
Auteurs: N. C. Beaulieu;Yixing Zhang;
Apparue dans: IEEE Communications Letters
Date publication: 05.-2017, volume: 21, issue:5, pages: 1003 - 1006
Editeur: IEEE
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» Live Prefetching for Mobile Computation Offloading
Résumé:
Mobile computation offloading refers to techniques for offloading computation intensive tasks from mobile devices to the cloud so as to lengthen the formers’ battery lives and enrich their features. The conventional designs fetch (transfer) user-specific data from mobiles to the cloud prior to computing, called offline prefetching. However, this approach can potentially result in excessive fetching of large volumes of data and cause heavy loads on radio-access networks. To solve this problem, the novel technique of live prefetching, which seamlessly integrates the task-level computation prediction and prefetching within the cloud-computing process of a large program with numerous tasks, is proposed in this paper. The technique avoids excessive fetching but retains the feature of leveraging prediction to reduce the program runtime and mobile transmission energy. By modeling the tasks in an offloaded program as a stochastic sequence, stochastic optimization is applied to design fetching policies to minimize mobile energy consumption under a deadline constraint. The policies enable real-time control of the prefetched-data sizes of candidates for future tasks. For slow fading, the optimal policy is derived and shown to have a threshold-based structure, selecting candidate tasks for prefetching and controlling their prefetched data based on their likelihoods. The result is extended to design close-to-optimal prefetching policies to fast fading channels. Compared with fetching without prediction, live prefetching is shown theoretically to always achieve reduction on mobile energy consumption.
Auteurs: Seung-Woo Ko;Kaibin Huang;Seong-Lyun Kim;Hyukjin Chae;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3057 - 3071
Editeur: IEEE
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» Load Optimization With User Association in Cooperative and Load-Coupled LTE Networks
Résumé:
We extend the problem of optimizing user association for load balancing in cellular networks along 2-dimensions. First, we consider joint transmission, which is one of the coordinated multipoint techniques with which a user may be simultaneously served by multiple base stations. Second, we account for, mathematically, the coupling relation between the base stations’ load levels that are dependent on each other due to inter-cell interference. We formulate two optimization problems, sum load minimization (MinSumL) and maximum load minimization (MinMaxL). We prove that both MinSumL and MinMaxL are $mathcal {NP}$ -hard. We propose a mixed integer linear programming based scheme by means of linearization. This approach also leads to a bounding scheme for performance benchmarking. Then, we derive a set of partial optimality conditions. Fulfillment of the conditions will guarantee performance improvement for both MinSumL and MinMaxL. A solution algorithm is then derived based on the conditions. Simulation results are provided to demonstrate the effectiveness of the approaches.
Auteurs: Lei You;Di Yuan;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 3218 - 3231
Editeur: IEEE
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» Local Controllability of the Two-Link Magneto-Elastic Micro-Swimmer
Résumé:
A recent promising technique for robotic micro-swimmers is to endow them with a magnetization and apply an external magnetic field to provoke their deformation. In this technical note, we consider a simple planar micro-swimmer model made of two magnetized segments connected by an elastic joint, controlled via a magnetic field. After recalling the analytical model, we establish a local controllability result around the straight position of the swimmer.
Auteurs: Laetitia Giraldi;Jean-Baptiste Pomet;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 05.-2017, volume: 62, issue:5, pages: 2512 - 2518
Editeur: IEEE
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» Local Defect Density in Polycrystalline High-k Dielectrics: CAFM-Based Evaluation Methodology and Impact on MOSFET Variability
Résumé:
A methodology to determine with nanometer resolution the defect density in polycrystalline HfO2 layers has been developed. This methodology is based on experimental data measured with conductive atomic force microscopy and the obtained results have been validated using Kelvin prove force microscopy measurements. The local defect density ( $rho _{mathsf {ox}}$ ) and thickness ( $text{t}_{mathsf {ox}}$ ) of the gate dielectric have been included into a device simulator to evaluate their impact on the $text{I}_{mathsf {D}}text{V}_{mathsf {G}}$ curves of MOSFETs.
Auteurs: C. Couso;M. Porti;J. Martin-Martinez;A. J. Garcia-Loureiro;N. Seoane;M. Nafria;
Apparue dans: IEEE Electron Device Letters
Date publication: 05.-2017, volume: 38, issue:5, pages: 637 - 640
Editeur: IEEE
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» Localization of Radial Deformation and Its Extent in Power Transformer HV Winding Using Stationary UWB Antennas
Résumé:
In this paper, three monitoring stages of detection, localization, and extent determination of radial deformation in power transformer winding using stationary ultra-wideband antennas, are investigated. For this purpose, two types of radial deformation are implemented on the actual transformer high-voltage winding. The first type is a modeled bulgy mechanical deformation, which its extent and reversibility may be changed and it can occur in different positions. The second type is an actual radial deformation applied to the winding. Hyperboloid method and 2-D locus of the winding are adopted in the localization stage. To perform a precise analysis of the received signals, matched filter technique is employed. The extent of the deformation is also determined by magnitude Euclidean distance index. The experimental results prove the effectiveness of the proposed method.
Auteurs: H. Rahbarimagham;S. Esmaeili;G. B. Gharehpetian;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:10, pages: 3184 - 3192
Editeur: IEEE
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» Localizing Microaneurysms in Fundus Images Through Singular Spectrum Analysis
Résumé:
Goal: Reliable recognition of microaneurysms (MAs) is an essential task when developing an automated analysis system for diabetic retinopathy (DR) detection. In this study, we propose an integrated approach for automated MA detection with high accuracy. Methods: Candidate objects are first located by applying a dark object filtering process. Their cross-section profiles along multiple directions are processed through singular spectrum analysis. The correlation coefficient between each processed profile and a typical MA profile is measured and used as a scale factor to adjust the shape of the candidate profile. This is to increase the difference in their profiles between true MAs and other non-MA candidates. A set of statistical features of those profiles is then extracted for a K-nearest neighbor classifier. Results: Experiments show that by applying this process, MAs can be separated well from the retinal background, the most common interfering objects and artifacts. Conclusion: The results have demonstrated the robustness of the approach when testing on large scale datasets with clinically acceptable sensitivity and specificity. Significance: The approach proposed in the evaluated system has great potential when used in an automated DR screening tool or for large scale eye epidemiology studies.
Auteurs: Su Wang;Hongying Lilian Tang;Lutfiah Ismail Al turk;Yin Hu;Saeid Sanei;George Michael Saleh;Tunde Peto;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 05.-2017, volume: 64, issue:5, pages: 990 - 1002
Editeur: IEEE
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» Logic-Form-Equation-Based Active Capacitor Voltage Balancing Control Technique for Stacked Multicell Converters
Résumé:
This paper proposes a novel active capacitor voltage balancing technique for stacked multicell (SM) converters. The proposed active capacitor voltage balancing control method detects the direction of the load current and measures the voltage of flying capacitors (FCs) to generate a proper switching state in order to form the required output voltage level and regulate the FC voltages at their desired reference levels. The proposed active capacitor voltage balancing control technique can modulate the output voltage through any of the pulse-width-modulation (PWM) techniques such as the phase-shifted carrier PWM or the level-shifted-carrier PWM. The foremost advantage of the proposed active control technique is that it does not demand any complex computations because it is not based on the optimization of the FC voltage-deviation cost functions. A thorough set of simulation results and experimental measurements for the five-level and seven-level SM converters are provided to validate the proposed active capacitor voltage balancing control method.
Auteurs: Arash Khoshkbar Sadigh;Vahid Dargahi;Keith A. Corzine;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 05.-2017, volume: 64, issue:5, pages: 3456 - 3466
Editeur: IEEE
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» Logical Correlation-Based Sleep Scheduling for WSNs in Ambient-Assisted Homes
Résumé:
This paper proposes a logical correlation-based sleep scheduling mechanism (LCSSM) to implement energy-efficient wireless sensor networks (WSNs) in ambient-assisted homes (AAHs). LCSSM analyzes sensory data generated by different human behaviors to detect the logical correlations between sensor nodes in an AAH. By utilizing the particular logical correlations of an AAH to predict its usage status, LCSSM deactivates sensor nodes accordingly to save energy when they are not expected to sense any valuable event. Evaluation results based on real life-logs have validated that LCSSM not only reduces the energy consumption of WSNs significantly, but also retains their quality of sensing successfully, e.g., with a moderate assumption on the duty cycling ratio and hardware configuration of sensor nodes, LCSSM successfully senses 98.7% valuable events with an average of 37.0% usual energy consumption, and extends the life time of WSNs by 63.4%.
Auteurs: Wei Liu;Yozo Shoji;Ryoichi Shinkuma;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:10, pages: 3207 - 3218
Editeur: IEEE
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» Longitudinal Electro-Optic Probe for the Transient Analysis of the Radial Field Surrounding a Three-Phase Cable
Résumé:
In this paper, we present the potentialities of the electro-optic technique for the radial electric field transient analysis of a three-phase power cable. A longitudinal electro-optic probe performing real time characterization of the field surrounding the cable has been developed. The measurement gives the transient evolution of the radial component of the field. The analysis provides information on amplitude, position, and phase of the conductors in the multicore cable. Theoretical analysis, simulations, and experimental measurements are in agreement and demonstrate the contactless voltage diagnostic of multicore cables.
Auteurs: Laurane Gillette;Gwenaël Gaborit;Jean Dahdah;Anne Grau;Valérie Murin;Lionel Duvillaret;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2807 - 2813
Editeur: IEEE
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» Loop Shaping of a Wide-Area Damping Controller Using HVDC
Résumé:
Insufficiently damped inter-area oscillatory behavior in large power systems may be mitigated by the application of a feedback control system. Thorough investigation of the resonant features unique to the western North American power system suggests that the modulation of active power using high-voltage dc has great impact on retaining system stability when actuation is provided by the geographically expansive pacific dc intertie transmission line. The controller is limited in bandwidth by the influences of time delay, sensor and actuator dynamics, and specific plant characteristics. While proportional feedback of the scaled difference of two disparate bus frequencies has shown to be a valid method for controlling this particular system in previous work, the authors submit that a shaped loop transmission function provides performance and noise response improvement with guaranteed stability in saturation. Results of simulations using a high fidelity model of the system show the efficacy of the approach.
Auteurs: Dakota Roberson;John F. O’Brien;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 05.-2017, volume: 32, issue:3, pages: 2354 - 2361
Editeur: IEEE
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» Low-Complexity Image and Video Coding Based on an Approximate Discrete Tchebichef Transform
Résumé:
The usage of linear transformations has great relevance for data decorrelation applications, like image and video compression. In that sense, the discrete Tchebichef transform (DTT) possesses useful coding and decorrelation properties. The DTT transform kernel does not depend on the input data and fast algorithms can be developed to real-time applications. However, the DTT fast algorithm presented in literature possess high computational complexity. In this paper, we introduce a new low-complexity approximation for the DTT. The fast algorithm of the proposed transform is multiplication free and requires a reduced number of additions and bit-shifting operations. Image and video compression simulations in popular standards show good performance of the proposed transform. Regarding hardware resource consumption for FPGA shows a 43.1% reduction in configurable logic blocks and ASIC place and route realization shows a 57.7% reduction in the area-time figure compared with the 2D version of the exact DTT.
Auteurs: Paulo A. M. Oliveira;Renato J. Cintra;Fábio M. Bayer;Sunera Kulasekera;Arjuna Madanayake;
Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology
Date publication: 05.-2017, volume: 27, issue:5, pages: 1066 - 1076
Editeur: IEEE
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» Low-Cost 3-D Flow Estimation of Blood With Clutter
Résumé:
Volumetric flow rate estimation is an important ultrasound medical imaging modality that is used for diagnosing cardiovascular diseases. Flow rates are obtained by integrating velocity estimates over a cross-sectional plane. Speckle tracking is a promising approach that overcomes the angle dependency of traditional Doppler methods, but suffers from poor lateral resolution. Recent work improves lateral velocity estimation accuracy by reconstructing a synthetic lateral phase (SLP) signal. However, the estimation accuracy of such approaches is compromised by the presence of clutter. Eigen-based clutter filtering has been shown to be effective in removing the clutter signal; but it is computationally expensive, precluding its use at high volume rates. In this paper, we propose low-complexity schemes for both velocity estimation and clutter filtering. We use a two-tiered motion estimation scheme to combine the low complexity sum-of-absolute-difference and SLP methods to achieve subpixel lateral accuracy. We reduce the complexity of eigen-based clutter filtering by processing in subgroups and replacing singular value decomposition with less compute-intensive power iteration and subspace iteration methods. Finally, to improve flow rate estimation accuracy, we use kernel power weighting when integrating the velocity estimates. We evaluate our method for fast- and slow-moving clutter for beam-to-flow angles of 90° and 60° using Field II simulations, demonstrating high estimation accuracy across scenarios. For instance, for a beam-to-flow angle of 90° and fast-moving clutter, our estimation method provides a bias of −8.8% and standard deviation of 3.1% relative to the actual flow rate.
Auteurs: Siyuan Wei;Ming Yang;Jian Zhou;Richard Sampson;Oliver D. Kripfgans;J. Brian Fowlkes;Thomas F. Wenisch;Chaitali Chakrabarti;
Apparue dans: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Date publication: 05.-2017, volume: 64, issue:5, pages: 772 - 784
Editeur: IEEE
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» Low-Cost Architecture of Modified Daubechies Lifting Wavelets Using Integer Polynomial Mapping
Résumé:
This brief proposes a modified version of the popular lifting algorithm of Daubechies-4 (D4) and Daubechies-6 (D6) wavelets and its efficient implementation using integer polynomial mapping (IPM). At first, an improved polyphase matrix for D4 is presented that eliminates one filter coefficient completely without losing any accuracy. Then, IPM is applied to encode the remaining irrational coefficients. As a result, computation error due to irrational numbers in the conventional method is significantly reduced, resulting in better image reconstruction. For D6, a two-level optimization scheme combined with the resource sharing of coefficients is applied that results in simplified hardware architecture with much fewer resources.
Auteurs: Md. Mehedi Hasan;Khan A. Wahid;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 05.-2017, volume: 64, issue:5, pages: 585 - 589
Editeur: IEEE
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» Low-Cost, Direct-Fed Slot Antenna Built in Metal Cover of Notebook Computer for 2.4-/5.2-/5.8-GHz WLAN Operation
Résumé:
The slot antenna has been utilized for some recent notebook computers on the market. The FR4 substrates are usually required to print the metal patterns for coupled-feeding the 2.4 GHz (2400–2484 MHz) slot and also for contributing the 5.2 GHz (5150–5350 MHz) and 5.8 GHz (5725–5825 MHz) bands. This communication presents a simple, direct-fed slot antenna with a low profile of 7 mm to the top edge of the metal cover for 2.4-/5.2-/5.8-GHz WLAN operation. The antenna design did not require any substrate and can be implemented directly in the metal cover of a notebook computer at low cost. The design comprised two parallel-connected, 0.5-wavelength-slot portions, formed in a linear structure of length 79 mm and constant width 2 mm, and fed by a common antenna feed port using a mini-coaxial cable. The larger slot generated a 0.5-wavelength resonant mode in the 2.4-GHz band and a 1-wavelength mode for 5.2-GHz operation. The smaller slot operated in a 0.5-wavelength resonant mode, which covered the 5.8-GHz band. With a matching inductor properly set in the slot, good input impedance over the 2.4-, 5.2-, and 5.8-GHz bands can be attained.
Auteurs: Cheng-Tse Lee;Saou-Wen Su;Shu-Chuan Chen;Chen-Shuo Fu;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 05.-2017, volume: 65, issue:5, pages: 2677 - 2682
Editeur: IEEE
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» Low-Rank and Adaptive Sparse Signal (LASSI) Models for Highly Accelerated Dynamic Imaging
Résumé:
Sparsity-based approaches have been popular in many applications in image processing and imaging. Compressed sensing exploits the sparsity of images in a transform domain or dictionary to improve image recovery fromundersampledmeasurements. In the context of inverse problems in dynamic imaging, recent research has demonstrated the promise of sparsity and low-rank techniques. For example, the patches of the underlying data are modeled as sparse in an adaptive dictionary domain, and the resulting image and dictionary estimation from undersampled measurements is called dictionary-blind compressed sensing, or the dynamic image sequence is modeled as a sum of low-rank and sparse (in some transform domain) components (L+S model) that are estimated from limited measurements. In this work, we investigate a data-adaptive extension of the L+S model, dubbed LASSI, where the temporal image sequence is decomposed into a low-rank component and a component whose spatiotemporal (3D) patches are sparse in some adaptive dictionary domain. We investigate various formulations and efficient methods for jointly estimating the underlying dynamic signal components and the spatiotemporal dictionary from limited measurements. We also obtain efficient sparsity penalized dictionary-blind compressed sensing methods as special cases of our LASSI approaches. Our numerical experiments demonstrate the promising performance of LASSI schemes for dynamicmagnetic resonance image reconstruction from limited k-t space data compared to recent methods such as k-t SLR and L+S, and compared to the proposed dictionary-blind compressed sensing method.
Auteurs: Saiprasad Ravishankar;Brian E. Moore;Raj Rao Nadakuditi;Jeffrey A. Fessler;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 05.-2017, volume: 36, issue:5, pages: 1116 - 1128
Editeur: IEEE
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» Low-Rank Spatial Channel Estimation for Millimeter Wave Cellular Systems
Résumé:
The tremendous bandwidth available in the millimeter wave frequencies above 10 GHz have made these bands an attractive candidate for next-generation cellular systems. However, reliable communication at these frequencies depends critically on beamforming with very high-dimensional antenna arrays. Estimating the channel sufficiently accurately to perform beamforming can be challenging due to both low coherence time and a large number of antennas. Also, the measurements used for channel estimation may need to be made with analog beamforming, where the receiver can “look” in only one direction at a time. This paper presents a novel method for estimation of the receive-side spatial covariance matrix of a channel from a sequence of power measurements made in different angular directions. It is shown that maximum likelihood estimation of the covariance matrix reduces to a non-negative matrix completion problem. We show that the non-negative nature of the covariance matrix reduces the number of measurements required when the matrix is low-rank. The fast iterative methods are presented to solve the problem. Simulations are presented for both single-path and multi-path channels using models derived from real measurements in New York City at 28 GHz.
Auteurs: Parisa A. Eliasi;Sundeep Rangan;Theodore S. Rappaport;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 05.-2017, volume: 16, issue:5, pages: 2748 - 2759
Editeur: IEEE
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» Low-Temperature, Solution-Processed, 3-D Complementary Organic FETs on Flexible Substrate
Résumé:
Vertical stacking of thin-film transistors is an effective way to reduce the footprint of a device, thus increases transistor density in complex flexible electronic applications without reducing the feature size and resolution of the patterning tools. In this paper, we report a 3-D complementary organic FET fabricated on a plastic substrate by stacking a bottom-gate top-contact p-type transistor on a top-gate bottom-contact n-type transistor with a gate shared between the two. We used high-performance polymer semiconductors, poly [(E)-2, 7-bis (2 decyltetradecyl) 4 methyl 9 (5 (2 (5 methylthiophen 2 yl) vinyl) thiophen 2 yl) benzo [lmn] [3, 8] phenanthroline-1, 3, 6, 8 (2H, 7H)-tetraone] for n-type devices and poly [2, 5-bis (7-decylnonadecyl) pyrrolo [3, 4-c] pyrrole-1, 4 (2H, 5H)-dione-(E) 1,2 bis (5 (thiophen 2 yl) selenophen 2 yl) ethene] for p-type devices to fabricate the vertically stacked organic transistors along with a Cytop and cross-linked poly (4-vinylphenol) bilayer and Poly (Methyl Methacrylate) gate dielectric. A 3-D flexible complementary organic inverter exhibits a maximum static voltage gain of $thickapprox 18$ V/V and high noise immunity of up to 60% of ${V} _{mathrm {DD}}$ /2. The 3-D transistors show hysteresis-free $I$ $V$ characteristics despite of low-temperature processes. Moreover, we discuss the influence of cross-linker concentration and the processing temperature of the PVP dielectric film on the degree of hysteresis in $I$ $V$ characteristics.
Auteurs: Sujeong Kyung;Jimin Kwon;Yun-Hi Kim;Sungjune Jung;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 05.-2017, volume: 64, issue:5, pages: 1955 - 1959
Editeur: IEEE
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» LTCC-Integrated $H$ -Plane Bends for THz Antenna-in-Package Solution
Résumé:
We present a compact terahertz antenna-in-package solution using a substrate integrated waveguide (SIW), which connects an integrated circuit (IC) to an SIW antenna. To suppress the leakage of electromagnetic waves due to bending a low-temperature cofired ceramic (LTCC) substrate, an H-plane bend SIW in the LTCC was investigated using the E-plane split-block technology. We introduced an IC with a CPW-to-waveguide transition into the hollow SIW. The insertion loss, estimated by measuring a back-to-back transition with the H-plane-bend SIW, is 1.6 dB at 300 GHz, and 49-GHz bandwidth with less than 10-dB return loss is achieved.
Auteurs: Takuro Tajima;Ho-Jin Song;Hideaki Matsuzaki;Makoto Yaita;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 05.-2017, volume: 27, issue:5, pages: 440 - 442
Editeur: IEEE
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» Magnetic Field Analysis for 3-D Positioning Applications
Résumé:
This paper proposes an analysis of the quasi-stationary magnetic field generated by coils and its applicability to 3-D short-range positioning scenarios. Starting from a theoretical background, an approximation of the induced voltage in a sensor coil is developed and analyzed. Then, the design and performance of a short-range magnetic field-based positioning system is described. The system is realized by using three-axis field generating coils and a three-axis sensor coil. It uses resonance properties to decrease current and power consumption requirements. The system is targeted for simple and low-cost applications, requiring subdecimeter accuracies over short ranges of approximately a couple of meters. The realized prototype, validated through in-field measurements, features a positioning error in the order of 4–5 cm over an area of 1.15 m \times 1.55 m \times 0.8 m.
Auteurs: Valter Pasku;Alessio De Angelis;Guido De Angelis;Antonio Moschitta;Paolo Carbone;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 05.-2017, volume: 66, issue:5, pages: 935 - 943
Editeur: IEEE
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» Magnetic Fluid Based High Precision Temperature Sensor
Résumé:
We have developed a high precision (3.7 mK) temperature sensor using nanomagnetic fluid bearing. The device is based on the basic principle of Charles law (v $propto $ T). For this, we have prepared kerosene-based magnetic fluid for ferrofluid bearing formation with permanent magnet. The ferrofluid bearing has very low coefficient of friction ( $mu _{f} = 0.002$ ), and provides a frictionless movement and perfect sealing. The device is highly sensitive as it uses air as a working media whose coefficient of volume expansion (0.0036) is much larger (20 times) than mercury (0.00018), ethanol (0.00026), and so on usually used in expansion-based thermometers. At constant atmospheric pressure (1 atm), a temperature variation of 1 °C causes a variation of 20 mm (capillary diameter 5 mm) in the position of fluid column. The device has been calibrated and tested using standard calibrated equipment’s. The device shows the high sensitivity of 3.7 (± 0.2) mK and can be used where high accuracy in temperature measurements is required. The device sensitivity and range is easily customizable. The device is capable of finding many useful applications, viz., standards and the calibration of thermometers.
Auteurs: Saurabh Pathak;Komal Jain; Noorjahan;Vinod Kumar;Rajendra Prasad Pant;
Apparue dans: IEEE Sensors Journal
Date publication: 05.-2017, volume: 17, issue:9, pages: 2670 - 2675
Editeur: IEEE
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» Maintenance strategy based on reliability analytical models for three parallel mechanical transformation machines
Résumé:
The purpose of this article is to formulate a maintenance strategy for three parallel machines in a mechanical manufacture. The research method was the quantitative modeling, based on analytical models. Time between failures (TBF) and time-to-repair (TTR) data since April 2014 to September 2015 were modelled for the three machines. Weibull distribution fitted all the TBF data. Lognormal distribution fitted TTR for machine 3. The availability Av(t) were calculated for each machine, remaining between 97% to 98%. Based on analytical models, it was defined that the best maintenance strategy for the system is the corrective maintenance.
Auteurs: Miguel Afonso Sellitto;William Brusius Jr;
Apparue dans: IEEE Latin America Transactions
Date publication: 05.-2017, volume: 15, issue:5, pages: 988 - 993
Editeur: IEEE
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» Making a Difference [From the Editor's Desk]
Résumé:
Presents the introductory editorial for this issue of the publication.
Auteurs: Lanny Floyd;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 05.-2017, volume: 23, issue:3, pages: 3 - 3
Editeur: IEEE
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» Malevolent Activity Detection with Hypergraph-Based Models
Résumé:
We propose a hypergraph-based framework for modeling and detecting malevolent activities. The proposed model supports the specification of order-independent sets of action symbols along with temporal and cardinality constraints on the execution of actions. We study and characterize the problems of consistency checking, equivalence, and minimality of hypergraph-based models. In addition, we define and characterize the general activity detection problem, that amounts to finding all subsequences that represent a malevolent activity in a sequence of logged actions. Since the problem is intractable, we also develop an index data structure that allows the security expert to efficiently extract occurrences of activities of interest.
Auteurs: Antonella Guzzo;Andrea Pugliese;Antonino Rullo;Domenico Saccà;Antonio Piccolo;
Apparue dans: IEEE Transactions on Knowledge and Data Engineering
Date publication: 05.-2017, volume: 29, issue:5, pages: 1115 - 1128
Editeur: IEEE
Document complet vers site de l'éditeur
 


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