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

» Effects of Suspended Sediment on Salinity Measurements
Abstract:
Widely used conductivity-based salinity measurements may be affected by suspended sediments. Two sets of experiments were carried out to analyze the effects of sediment concentration and grain size on salinity measurements. The results show that the salinities measured by conductivity-temperature-depth probes in turbid saltwater are all lower than those measured in clear water. The absolute values of the difference in salinity between turbid saltwater and clear saltwater increase with increasing reference salinity and suspended sediment concentration (SSC). Moreover, the finer the sediment particles are, generally, the greater is their influence upon salinity measurement. For an SSC of 70 g/L and a reference salinity of 30 g/kg, the absolute values of salinity difference were 1.882, 1.675, and 1.285 PSU for the fine, median, and coarse sediment particles, respectively. These differences are attributed to blocking, occupying, adsorption, and flocculation effects.
Autors: Zhi-Lin Sun;Jian-Ge Jiao;Sen-Jun Huang;Yang-Yang Gao;Hao-Che Ho;Dan Xu;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Jan 2018, volume: 43, issue:1, pages: 56 - 65
Publisher: IEEE
 
» Efficiency of an Exciplex DBD Lamp Excited Under Different Methods
Abstract:
Three different electrical generators have been designed and used to supply an exciplex dielectric barrier discharge lamp in order to elucidate the influence of each one of these supplying strategies over the system performance; the first method consists on supplying the lamp with short bipolar voltage pulses; the second and third methods are based on semiresonant converters were current pulses, of controlled duration and magnitude, are injected into the lamp. For each one of the generators, measurements of the lamp and supply efficiency, are performed and analyzed, at different levels of power (up to 130 W) and operating frequencies (60–90 kHz). From the experimental results, the pulsed voltage-mode approach has allowed obtaining the highest lamp efficiency (7%), yet the maximum supply efficiency is offered by the resonant mode supplies. On the basis of the lamp and the supply efficiencies, the whole system performance is analyzed.
Autors: David Florez;Dmitry Schitz;Hubert Piquet;Rafael Diez;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jan 2018, volume: 46, issue:1, pages: 140 - 147
Publisher: IEEE
 
» Efficient Analog Circuits for Boolean Satisfiability
Abstract:
Efficient solutions to nonpolynomial (NP)-complete problems would significantly benefit both science and industry. However, such problems are intractable on digital computers based on the von Neumann architecture, thus creating the need for alternative solutions to tackle such problems. Recently, a deterministic, continuous-time dynamical system (CTDS) was proposed [1] to solve a representative NP-complete problem, Boolean Satisfiability (SAT). This solver shows polynomial analog time-complexity on even the hardest benchmark -SAT () formulas, but at an energy cost through exponentially driven auxiliary variables. This paper presents a novel analog hardware SAT solver, AC-SAT, implementing the CTDS via incorporating novel, analog circuit design ideas. AC-SAT is intended to be used as a coprocessor and is programmable for handling different problem specifications. It is especially effective for solving hard -SAT problem instances that are challenging for algorithms running on digital machines. Furthermore, with its modular design, AC-SAT can readily be extended to solve larger size problems, while the size of the circuit grows linearly with the product of the number of variables and the number of clauses. The circuit is designed and simulated based on a 32-nm CMOS technology. Simulation Program with Integrated Circuit Emphasis (SPICE) simulation results show speedup factors of ~104 on even the hardest 3-SAT problems, when compared with a state-of-the-art SAT solver on digital computers. As an example, for hard problems with clauses, solutions are found within from a few nanoseconds to a few hundred nanoseconds.
Autors: Xunzhao Yin;Behnam Sedighi;Melinda Varga;Mária Ercsey-Ravasz;Zoltán Toroczkai;Xiaobo Sharon Hu;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jan 2018, volume: 26, issue:1, pages: 155 - 167
Publisher: IEEE
 
» Efficient Image Preprocessing of Digital Holograms of Marine Plankton
Abstract:
A set of image preprocessing approaches are developed for processing plankton images reconstructed from digital holograms. First, a threshold-based algorithm of image segmentation is proposed and applied to extract the regions of plankton from the original digital images. To improve the performance of image segmentation, an appropriate filter is adopted to reduce the background noise from the image and the image gray level is adjusted to enhance the image contrast. Second, we develop a novel and efficient edge detection method purposefully for the binary images. Third, we propose and use a simple chain-code-based algorithm to eliminate the single-pixel branches along the shape boundary, which will help boundary tracing work stably. Then, an algorithm is improved and applied to trace the boundaries of the plankton regions. This algorithm is optimized based on the relationship between two consecutive chain-codes such that it is fast on implementation. Finally, break points of the shape boundary are efficiently detected based on chain-codes and the boundary is represented compactly by a polygon comprised of those points. After images are preprocessed by these approaches, some redundant information of shape is reduced that will accelerate the running speeds of further image processing and aid identification and classification of plankton at species level. We analyze the accuracy and efficiency of our algorithms. The results show that our algorithm of image segmentation has a good performance in accuracy. Our edge detection method also outperforms the commonly used edge detection methods in terms of localization performance and the running time.
Autors: Zonghua Liu;John Watson;Alastair Allen;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Jan 2018, volume: 43, issue:1, pages: 83 - 92
Publisher: IEEE
 
» Efficient Multi-Rate Video Encoding for HEVC-Based Adaptive HTTP Streaming
Abstract:
Adaptive HTTP streaming requires a video to be encoded at multiple representations, that is, different qualities. Encoding these multiple representations is a computationally complex process, especially when using the recent High Efficiency Video Coding (HEVC) standard. In this paper, we consider a multi-rate HEVC encoder and identify four types of encoding information that can be reused from a high-quality reference encoding to speed up lower quality-dependent encodings. We show that the encoding decisions from the reference cannot be directly reused, as this would harm the overall rate-distortion (RD) performance. Thus, we propose methods to use the encoding information to constrain the RD optimization of the dependent encodings so that the encoding complexity is reduced while the RD performance is kept high. We additionally show that the proposed methods can be combined, leading to an efficient multi-rate encoder that exhibits high RD performance and substantial complexity reduction. Results show that the encoding time for 12 representations at different spatial resolutions and signal qualities can be reduced on average by 38%, while the average bitrate increases by less than 1%.
Autors: Damien Schroeder;Adithyan Ilangovan;Martin Reisslein;Eckehard Steinbach;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jan 2018, volume: 28, issue:1, pages: 143 - 157
Publisher: IEEE
 
» Efficient Multi-View 3D Video Multicast with Depth-Image-Based Rendering in LTE-Advanced Networks with Carrier Aggregation
Abstract:
With the recent emergence of naked-eye 3D mobile devices and various 3D-enabled laptops, service providers now afford the opportunity to provide mobile 3D video streaming in LTE-Advanced networks. Differing from traditional single-view 3D videos, multi-view 3D videos allow users to choose preferred view angles and thus are promising for new applications, such as free-viewpoint television (FTV). Nevertheless, enabling multi-view 3D video services may overwhelm the network resource when transmitting all views of every video. Fortunately, Depth-Image-Based Rendering (DIBR) allows each mobile client to synthesize the desired view from a nearby left view and right view, so that not all views of a video are necessarily transmitted. A new challenge with DIBR, however, is to carefully choose the transmitted views to limit the video distortion and minimize the bandwidth consumption. In this paper, therefore, we first formulate a new optimization problem, called View and MCS Selection (VMS) Problem, to minimize the bandwidth consumption for multi-view 3D video multicast in LTE networks. An algorithm, called View and MCS Aggregation (VMAG) is proposed to find the optimal solution to VMS. For Carrier Aggregation (CA) in LTE-Advanced networks, we formulate a new View, MCS and Carrier Selection (VMCS) Problem and prove that the problem is NP-Hard. We first design a dynamic programming algorithm, called the View Assignment with MCS and Carrier (VAMC) algorithm, to find the optimal solution for small instances. We then propose the View and MCS Aggregation with Carrier (VMAGC) algorithm based on VMAG to effectively find the near-optimal solution to VMCS. The simulation results show that bandwidth consumption can be effectively reduced by over 30 percent in VMS and VMCS.
Autors: Ji-Tang Lee;De-Nian Yang;Yu-Chun Chen;Wanjiun Liao;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2018, volume: 17, issue:1, pages: 85 - 98
Publisher: IEEE
 
» Efficient Performance of MLSSM-MLFMA Algorithm Using Adaptive Grouping Technique for Electromagnetic Problems
Abstract:
In this communication, an adaptive grouping technique-based multilevel simply sparse method multilevel fast multipole algorithm (MLSSM-MLFMA) scheme is proposed to analyze objects with local fine structures efficiently. The MLSSM-MLFMA algorithm utilizes MLFMA to accelerate dealing with the boxes whose size is larger than 0.2 wavelength and uses MLSSM to decompose the boxes whose size is less than 0.2 wavelength. Meanwhile, the adaptive grouping technique is applied to improve the performance of MLSSM-MLFMA algorithm. The conventional octree-based grouping scheme divides the target into boxes with the same size at each level. It leads to some boxes that contain a large number of discrete unknowns, while some boxes contain fewer unknowns to simulate the object with local fine structures. Therefore, the computational efficiency of MLSSM-MLFMA algorithm will be improved. By using the proposed grouping technique, the memory requirements and computational times are much less than those of conventional octree-based grouping scheme for analyzing the objects with local fine structures.
Autors: Caiping Wang;Zhaoneng Jiang;Xuguang Qiao;Ting Wan;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 493 - 496
Publisher: IEEE
 
» Efficient Planar Caging Test Using Space Mapping
Abstract:
This paper presents an efficient algorithm to test whether a planar object can be caged by a formation of point agents (point fingertips or point mobile robots). The algorithm is based on a space mapping between the 2-D work space ( space) and the 3-D configuration space ( space) of the given agent formation. When performing caging test on a planar object, the algorithm looks up the space mapping to recover the space of the given agent formation, labels the recovered space, and counts the number of labeled surfaces to judge the success of caging. The algorithm is able to work with various planar shapes, including objects with convex boundaries, concave boundaries, or holes. It can also respond quickly to varying agent formations and different object shapes. Experiments and analysis on different objects and fingertip formations demonstrate the completeness, robustness, and efficiency of our proposal.

Note to Practitioners—This paper proposes an algorithm to solve a geometric problem—find whether a given formation of planar points can constrain (or cage) a planar shape. Users can use the proposed algorithm to actuate a formation of robotic fingertips to perform caging-based grasping tasks or use the proposed algorithm to actuate a formation of mobile robots to perform cooperative transportation tasks. The algorithm inherits the merits of caging and helps users to avoid explicit force analysis. It offers robustness to avoid uncertainty in the tasks. The code of our work is in the supplementary material.

Autors: Weiwei Wan;Rui Fukui;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2018, volume: 15, issue:1, pages: 278 - 289
Publisher: IEEE
 
» Efficient Seafloor Classification and Submarine Cable Route Design Using an Autonomous Underwater Vehicle
Abstract:
This work presents an efficient method for designing submarine cable routes using online seafloor classification based on sidescan sonar scanlines, collected by an autonomous underwater vehicle (AUV). Currently, the cable routes are designed manually by experienced experts. Online seafloor classification and an automated route planning method using an AUV can improve the efficiency of construction of submarine cables. Sidescan sonar is a device commonly used for mapping the seafloor and detecting obstacles. An AUV equipped with a sidescan sonar is used to gather sonar scanlines to perform online seafloor classification and mapping. As the AUV operates, the gathered scanlines are analyzed to classify the seafloor using a probabilistic classifier based on Bayes' theorem with the naïve assumption. Based on the seafloor classification map, a probabilistic roadmap is generated. Then, an A* algorithm is applied to determine appropriate cable routes along the cable corridor, using the following five factors: seafloor classification, bathymetry, steepness of slope, angle of change of course, and cable length. Compared with an existing route planning method, the presented method of using an AUV with automatic decision making algorithm can efficiently support submarine cable construction. The favored route determined by the presented method was as acceptable as the route designed by experts.
Autors: Sheng-Wei Huang;Edward Chen;Jenhwa Guo;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Jan 2018, volume: 43, issue:1, pages: 7 - 18
Publisher: IEEE
 
» Efficient Use of Space-Time Clustering for Underwater Acoustic Communications
Abstract:
Underwater acoustical communication channels are characterized by the spreading of received signals in space (direction of arrival) and in time (delay). The spread is often limited to a small number of space-time clusters. In this paper, the space-time clustering is exploited in a proposed receiver designed for guard-free orthogonal frequency-division multiplexing with superimposed data and pilot signals. For separation of space clusters, the receiver utilizes a vertical linear array (VLA) of hydrophones, whereas for combining delay-spread signals within a space cluster, a time-domain equalizer is used. We compare a number of space-time processing techniques, including a proposed reduced-complexity spatial filter, and show that techniques exploiting the space-time clustering demonstrate an improved detection performance. The comparison is done using signals transmitted by a moving transducer, and recorded on a 14-element nonuniform VLA in sea trials at distances of 46 and 105 km.
Autors: Jianghui Li;Yuriy V. Zakharov;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Jan 2018, volume: 43, issue:1, pages: 173 - 183
Publisher: IEEE
 
» Electric Power Network State Tracking From Multirate Measurements
Abstract:
This paper proposes a novel tracking state estimator to process both fast-rate synchronized phasor and slow-rate supervisory control and data acquisition (SCADA) measurements. The former are assumed to be in limited number. The latter are exploited as and when they arrive to the control center. In order to restore observability, after each execution of the tracking state estimator, forecast SCADA measurements are used as pseudo-measurements in the next estimation. An event detection analysis allows assessing if the system is in quasi-steady-state. If so, an innovation analysis is performed to identify and eliminate erroneous SCADA measurements. The system state is computed by Hachtel’s augmented matrix method. The option of exploiting time-tagged SCADA measurements is also considered. The method is illustrated through detailed dynamic simulations of a test system evolving toward voltage collapse, with and without emergency control.
Autors: Boris A. Alcaide-Moreno;Claudio R. Fuerte-Esquivel;Mevludin Glavic;Thierry Van Cutsem;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2018, volume: 67, issue:1, pages: 33 - 44
Publisher: IEEE
 
» Electrical Circuit Modeling of Sensor Magneto-Impedances With a Square-Root Frequency Dependence
Abstract:
In this paper, a novel lumped electrical model for magneto-impedance sensors based on square-root of the frequency is introduced. The model is mathematically derived using an alternative approximation of that leads to an approximate transfer function with a finite number of products of poles and zeros. This approach can be easily implemented in circuit simulators, such as SPICE (Simulation Program with Integrated Circuit Emphasis) by means of current conveyors circuits and linear passive elements, such as resistors, capacitors, and inductors. These elements are interconnected using impedance converters based on Senani’s model to implement the poles and zeros of the transfer function. The scope and validity of the model were demonstrated through circuit simulations using spice, and compared with experimental results. The model can be used in the electronic signal conditioning stage for optimizing and/or for researching new cheap low-power practical electronics circuits.
Autors: Rafael Vargas-Bernal;Carlos A. De la Cruz Blas;Cristina Gómez-Polo;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 623 - 628
Publisher: IEEE
 
» Electrifying Water Buses: A Case Study on Diesel-to-Electric Conversion in Venice
Abstract:
This study presents the conversion of a diesel-based watercraft for public transportation in Venice, Italy, to an electric propulsion technology, with a view to wide future adoption of electrical transportation. It takes into account energy-storage systems, electrical machines, and drives and examines them in light of economic, environmental, and social issues. Some alternative solutions based on hybrid diesel-electric and full-electric (FE ) powertrains are compared in terms of weight, cost, and payback times. The comparison shows that a hybrid diesel-engine lithium (Li) battery (LB) is the best option for an easy first implementation, even when considering the existing infrastructure.
Autors: Massimo Guarnieri;Mattia Morandin;Antonio Ferrari;Pierpaolo Campostrini;Silverio Bolognani;
Appeared in: IEEE Industry Applications Magazine
Publication date: Jan 2018, volume: 24, issue:1, pages: 71 - 83
Publisher: IEEE
 
» Electromechanical Coupling Factor of Breast Tissue as a Biomarker for Breast Cancer
Abstract:
Goal: This research aims to validate a new biomarker of breast cancer by introducing electromechanical coupling factor of breast tissue samples as a possible additional indicator of breast cancer. Since collagen fibril exhibits a structural organization that gives rise to a piezoelectric effect, the difference in collagen density between normal and cancerous tissue can be captured by identifying the corresponding electromechanical coupling factor. Methods: The design of a portable diagnostic tool and a microelectromechanical systems (MEMS)-based biochip, which is integrated with a piezoresistive sensing layer for measuring the reaction force as well as a microheater for temperature control, is introduced. To verify that electromechanical coupling factor can be used as a biomarker for breast cancer, the piezoelectric model for breast tissue is described with preliminary experimental results on five sets of normal and invasive ductal carcinoma (IDC) samples in the 25–45 temperature range. Conclusion: While the stiffness of breast tissues can be captured as a representative mechanical signature which allows one to discriminate among tissue types especially in the higher strain region, the electromechanical coupling factor shows more distinct differences between the normal and IDC groups over the entire strain region than the mechanical signature. From the two-sample -test, the electromechanical coupling factor under compression shows statistically significant differences ( 0.0039) between the two groups. Significance: The increase in collagen density in breast tissue is an objective and reproducible characteristic of breast canc- r. Although characterization of mechanical tissue property has been shown to be useful for differentiating cancerous tissue from normal tissue, using a single parameter may not be sufficient for practical usage due to inherent variation among biological samples. The portable breast cancer diagnostic tool reported in this manuscript shows the feasibility of measuring multiple parameters of breast tissue allowing for practical application.
Autors: Kihan Park;Wenjin Chen;Marina A. Chekmareva;David J. Foran;Jaydev P. Desai;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jan 2018, volume: 65, issue:1, pages: 96 - 103
Publisher: IEEE
 
» Electron Field Emission Enhancement Based on Al-Doped ZnO Nanorod Arrays With UV Exposure
Abstract:
In this paper, Al-doped ZnO nanorods (AZO NRs) were successfully applied on glass substrates through hydrothermal synthesis growth with a fabrication field-emission (FE) device. The enhanced FE properties of AZO NRs were measured. The turn-on fields were reduced by 2.35 and 1.51 V/ in the dark and under UV light, and the enhanced field enhancement factors () were 5708 and 10137, respectively. Results show that the FE performances of AZO NRs were enhanced by the combined effect of increased carrier concentration and UV light illumination.
Autors: Zi-Hao Wang;Chih-Chiang Yang;Hsin-Chieh Yu;Hsin-Ting Yeh;Yu-Ming Peng;Yan-Kuin Su;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2018, volume: 65, issue:1, pages: 251 - 256
Publisher: IEEE
 
» Electronic Conduction Mechanisms in Insulators
Abstract:
The current density–electric field characteristics of four insulators of dramatically different electrical qualities are assessed in terms of their operative electronic conduction mechanisms. Conduction in the two high-quality insulators is dominated by Ohmic conduction and Fowler–Nordheim tunneling, whereas conduction in the two low-quality insulators involves Ohmic conduction and space-charge limited current (SCLC). Ohmic conduction and SCLC are somewhat puzzling mechanisms for contributing to insulator leakage current since they require the existence of an Ohmic contact at the cathode. Our conventional understanding of an Ohmic contact makes it difficult to ascertain how an Ohmic contact could be formed to a wide bandgap insulator. This Ohmic contact dilemma is resolved by formulating an equivalent circuit appropriate for assessing the characteristics of an insulator and then recognizing that an insulator Ohmic contact is obtained when the injection-limited current density from the cathode electrode is greater than that of the operative bulk-limited current density, i.e., Ohmic or SCLC for the four insulators under consideration.
Autors: Tsung-Han Chiang;John F. Wager;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2018, volume: 65, issue:1, pages: 223 - 230
Publisher: IEEE
 
» Eliminating Path Redundancy via Postconditioned Symbolic Execution
Abstract:
Symbolic execution is emerging as a powerful technique for generating test inputs systematically to achieve exhaustive path coverage of a bounded depth. However, its practical use is often limited by path explosion because the number of paths of a program can be exponential in the number of branch conditions encountered during the execution. To mitigate the path explosion problem, we propose a new redundancy removal method called postconditioned symbolic execution. At each branching location, in addition to determine whether a particular branch is feasible as in traditional symbolic execution, our approach checks whether the branch is subsumed by previous explorations. This is enabled by summarizing previously explored paths by weakest precondition computations. Postconditioned symbolic execution can identify path suffixes shared by multiple runs and eliminate them during test generation when they are redundant. Pruning away such redundant paths can lead to a potentially exponential reduction in the number of explored paths. Since the new approach is computationally expensive, we also propose several heuristics to reduce its cost. We have implemented our method in the symbolic execution engine KLEE [1] and conducted experiments on a large set of programs from the GNU Coreutils suite. Our results confirm that redundancy due to common path suffix is both abundant and widespread in real-world applications.
Autors: Qiuping Yi;Zijiang Yang;Shengjian Guo;Chao Wang;Jian Liu;Chen Zhao;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Jan 2018, volume: 44, issue:1, pages: 25 - 43
Publisher: IEEE
 
» Embedding Structured Contour and Location Prior in Siamesed Fully Convolutional Networks for Road Detection
Abstract:
Road detection from the perspective of moving vehicles is a challenging issue in autonomous driving. Recently, many deep learning methods spring up for this task, because they can extract high-level local features to find road regions from raw RGB data, such as convolutional neural networks and fully convolutional networks (FCNs). However, how to detect the boundary of road accurately is still an intractable problem. In this paper, we propose siamesed FCNs (named “s-FCN-loc”), which is able to consider RGB-channel images, semantic contours, and location priors simultaneously to segment the road region elaborately. To be specific, the s-FCN-loc has two streams to process the original RGB images and contour maps, respectively. At the same time, the location prior is directly appended to the siamesed FCN to promote the final detection performance. Our contributions are threefold: 1) An s-FCN-loc is proposed that learns more discriminative features of road boundaries than the original FCN to detect more accurate road regions. 2) Location prior is viewed as a type of feature map and directly appended to the final feature map in s-FCN-loc to promote the detection performance effectively, which is easier than other traditional methods, namely, different priors for different inputs (image patches). 3) The convergent speed of training s-FCN-loc model is 30% faster than the original FCN because of the guidance of highly structured contours. The proposed approach is evaluated on the KITTI road detection benchmark and one-class road detection data set, and achieves a competitive result with the state of the arts.
Autors: Qi Wang;Junyu Gao;Yuan Yuan;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2018, volume: 19, issue:1, pages: 230 - 241
Publisher: IEEE
 
» Empirical Evaluation of the Impact of Object-Oriented Code Refactoring on Quality Attributes: A Systematic Literature Review
Abstract:
Software refactoring is a maintenance task that addresses code restructuring to improve its quality. Many studies have addressed the impact of different refactoring scenarios on software quality. This study presents a systematic literature review that aggregates, summarizes, and discusses the results of 76 relevant primary studies (PSs) concerning the impact of refactoring on several internal and external quality attributes. The included PSs were selected using inclusion and exclusion criteria applied to relevant articles published before the end of 2015. We analyzed the PSs based on a set of classification criteria, including software quality attributes and measures, refactoring scenarios, evaluation approaches, datasets, and impact results. We followed the vote-counting approach to determine the level of consistency among the PS reported results concerning the relationship between refactoring and software quality. The results indicated that different refactoring scenarios sometimes have opposite impacts on different quality attributes. Therefore, it is false that refactoring always improves all software quality aspects. The vote-counting study provided a clear view of the impacts of some individual refactoring scenarios on some internal quality attributes such as cohesion, coupling, complexity, inheritance, and size, but failed to identify their impacts on external and other internal quality attributes due to insufficient findings.
Autors: Jehad Al Dallal;Anas Abdin;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Jan 2018, volume: 44, issue:1, pages: 44 - 69
Publisher: IEEE
 
» Empirical Model for Nonuniformly Doped Symmetric Double-Gate Junctionless Transistor
Abstract:
This paper demonstrates the influence of nonuniform doping on the electrostatics of symmetric double-gate junctionless transistor using empirical modeling scheme. To present the clear insight into the device electrostatics of nonuniform doped channel, the peak of the doping concentration has been varied from Si/SiO2 interface of front gate to the back gate. The parameters explored in this paper are surface potential, electric field, drain current, threshold voltage, subthreshold slope, and drain-induced barrier lowering for different straggle factors and channel lengths. By properly optimizing the straggle value and peak of the doping concentration, device performance can be tuned accordingly.
Autors: Vandana Kumari;Ayush Kumar;Manoj Saxena;Mridula Gupta;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2018, volume: 65, issue:1, pages: 314 - 321
Publisher: IEEE
 
» Emulation of Cyber-Physical Systems Using IEC-61499
Abstract:
Automation systems used in smart grids, transportation, and medical electronics are cyber physical in nature. Automation standards, such as IEC-61499, while well suited to the design of discrete controllers, are not ideally suited to model the dynamics of the plant. Such modeling is essential for emulation-based validation of the controllers in the cyber-physical systems (CPS) domain. We use a well-known formal model for CPS, called hybrid input output automata (HIOA), as the main vehicle in the proposed formulation. A physical process (the plant) may be described as a synchronous composition of a network of such HIOA. We provide an approach to transform such a network to a composite function block (CFB) in IEC-61499. This transformation is shown to be semantics preserving. Code generated from such plant models can be executed on a computer chip to provide real-time response to their adjoining controllers. Through practical examples, we illustrate the scalability and practicability of the proposed approach. The developed approach enables the emulation of physical processes in industrial automation without using the actual plant.
Autors: Avinash Malik;Partha S Roop;Nathan Allen;Théo Steger;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 380 - 389
Publisher: IEEE
 
» Enabling Cooperative Behavior for Building Demand Response Based on Extended Joint Action Learning
Abstract:
This paper explores the use of distributed intelligence to assist the integration of the demand as a flexible resource, to mitigate the emerging uncertainty in the power system, while fulfilling the customer's local needs, i.e., comfort management. More exactly, our contribution is twofold. First, we propose a novel cooperative and decentralized reinforcement learning method, dubbed extended joint action learning (eJAL). Second, we perform a comparison between eJAL to noncooperative decentralized decision making strategies, i.e., Q-learning, and a centralized game theoretic approach, i.e., Nash n-player game. This comparison has been conducted on the basis of grid support effectiveness and the loss of comfort for each customer. Various metrics were used to analyze the advantages and disadvantages of each method. We demonstrated that a range of flexibility requests can be met by providing an optimal energy portfolio of buildings without substantially violating comfort constraints. Moreover, we showed that the proposed eJAL method achieves the highest fairness index.
Autors: Luis A. Hurtado;Elena Mocanu;Phuong H. Nguyen;Madeleine Gibescu;René I. G. Kamphuis;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 127 - 136
Publisher: IEEE
 
» Enabling Low Contact Resistivity on n-Ge by Implantation After Ti Germanide
Abstract:
The process to form Ti germanide on P-implanted Ge ( cm−3) with low contact resistivity () was developed. Sequential deposition of Ti and TiN on n-Ge without annealing leads to rectifying – characteristic due to Fermi level pinning. With 600 °C annealing, Ohmic-like – behavior was achieved due to Ti germanide (C54 phase included) formation that depins Fermi level and makes of and Schottky barrier height for electron () of 0.22 eV. Even for 700 °C annealing, the Ti germanide exhibits comparable and good thermal stability without agglomeration, which is a concern of NiGe. By adopting additional P implantation after germanide, and can be further improved to -cm2 and 0.17 eV, respectively. The impr- vement is ascribed to the enhanced dopant segregation at the germanide/Ge interface that results in stronger dipoles and more significantly reduced and . The Ti germanide process paves a promising path to enable a next-generation Ge technology.
Autors: Chuan-Pu Chou;Hui-Hsin Chang;Yung-Hsien Wu;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2018, volume: 39, issue:1, pages: 91 - 94
Publisher: IEEE
 
» Enabling Security-Enhanced Attestation With Intel SGX for Remote Terminal and IoT
Abstract:
Along with the advent and popularity of cloud computing, Internet of Things, and bring your own device, the trust requirement for terminal devices has increased significantly. An untrusted terminal, a terminal that runs in an untrustworthy execution environment, may cause serious security issues for enterprise networks. With the release of Software Guard Extension, Intel has provided a promising way to construct trusted terminals and services. Utilizing this technology, we propose a security-enhanced attestation for remote terminals, which can achieve shielded execution for measurements and attestation programs. Furthermore, we present a policy-based measurement mechanism where sensitive data, including secret keys and policy details are concealed using the enclave-specific keys. We implement our attestation prototype on real platform with Intel Skylake processor. Evaluation results show that our attestation system can provide much stronger security guarantees, yet incurs small performance overhead.
Autors: Juan Wang;Zhi Hong;Yuhan Zhang;Yier Jin;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jan 2018, volume: 37, issue:1, pages: 88 - 96
Publisher: IEEE
 
» Encoded Semantic Tree for Automatic User Profiling Applied to Personalized Video Summarization
Abstract:
We propose an innovative method of automatic video summary generation with personal adaptations. User interests are mined from their personal image collections. To reduce the semantic gap, we propose to extract visual representations based on a novel semantic tree (SeTree). A SeTree is a hierarchy that captures the conceptual relationships between the visual scenes in a codebook. This idea builds upon the observation that such semantic connections among the elements have been overlooked in the previous work. To construct the SeTree, we adopt a normalized graph cut clustering algorithm by conjunctively exploiting visual features, textual information, and social user-image connections. Using this technique, we obtain an 8.1% improvement of normalized discounted cumulative gain in personalized video segments ranking compared with existing methods. Furthermore, to promote the interesting parts of a video, we extract a space–time saliency map and estimate the attractiveness of segments by kernel fitting and matching. A linear function is utilized to combine the two factors, based on which the playback rate of a video is adapted to generate the summary. We play the less important segments in a fast-forward mode to keep users updated with the context. Subjective experiments were conducted which showed that our proposed video summarization approach outperformed the state-of-the-art techniques by 6.2%.
Autors: Yifang Yin;Roshan Thapliya;Roger Zimmermann;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jan 2018, volume: 28, issue:1, pages: 181 - 192
Publisher: IEEE
 
» Encoded Sensing for Energy Efficient Wireless Sensor Networks
Abstract:
Energy efficient communication is a fundamental design problem in wireless networks significantly affecting network performance and the lifetime of wireless sensor networks (WSNs). We introduce encoded sensing—an approach for collaborative encoding and transmission of sensors data—that drastically reduces communication energy expenditure in WSN. Encoded sensing exploits the inherent spatial structure in sensed data to adaptively partition a WSN into groups of sensor nodes, so that nodes in each group sense highly correlated values. Each group encodes all individual measurements sensed by its nodes at time into a single binary sparse codeword via novel minimum distance combinatorial encoding local algorithm. When the codeword’s Hamming weight equals , a subset of nodes in the group cooperatively transmits a single binary symbol each. Upon receiving the bits, the sink has enough information to decode a measurement estimate, which is within a small error from each of the group nodes’ individual measurements. The error is bounded and guaranteed to satisfy a priori QoS accuracy requirements. We compare encoded sensing to non-cooperative state-of-the-art transmission protocols and demonstrate at least a factor of two in energy savings, without significant loss of measurement quality. Encoded sensing achieves at least 80% the energy savings of theoretically optimal cooperative transmission distributed beamforming architectures. We show by simulations and theoretical derivations that as the size of a node group grows the performance of encoded sensing converges to the optimal tr- nsmission energy efficiency.
Autors: Milen Nikolov;Zygmunt J. Haas;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 875 - 889
Publisher: IEEE
 
» Ends and Means
Abstract:
Even the smallest coding mistake can cause huge problems when it slips by testing. Finding it can be difficult, and retesting the fixed system can be expensive, but this certainly isn’t true for every type of problem. A defect found and fixed during coding is a fairly routine occurrence and not costlier than a defect found and fixed during design. Quite the opposite is usually true.
Autors: Gerard J. Holzmann;
Appeared in: IEEE Software
Publication date: Jan 2018, volume: 35, issue:1, pages: 14 - 17
Publisher: IEEE
 
» Energy Efficiency Aware Task Assignment with DVFS in Heterogeneous Hadoop Clusters
Abstract:
While Hadoop ecosystems become increasingly important for practitioners of large-scale data analysis, they also incur tremendous energy cost. This trend is driving up the need for designing energy-efficient Hadoop clusters in order to reduce the operational costs and the carbon emission associated with its energy consumption. However, despite extensive studies of the problem, existing approaches for energy efficiency have not fully considered the heterogeneity of both workload and machine hardware found in production environments. In this paper, we find that heterogeneity-oblivious task assignment approaches are detrimental to both performance and energy efficiency of Hadoop clusters. Our observation shows that even heterogeneity-aware techniques that aim to reduce the job completion time do not guarantee a reduction in energy consumption of heterogeneous machines. We propose a heterogeneity-aware task assignment approach, E-Ant, that aims to improve the overall energy consumption in a heterogeneous Hadoop cluster without sacrificing job performance. It adaptively schedules heterogeneous workloads on energy-efficient machines, without a priori knowledge of the workload properties. E-Ant employs an ant colony optimization approach that generates task assignment solutions based on the feedback of each task’s energy consumption reported by Hadoop TaskTrackers in an agile way. Furthermore, we integrate DVFS technique with E-Ant to further improve the energy efficiency of heterogeneous Hadoop clusters. It relies on a DVFS controller to dynamically scale the CPU frequency of each slave machine in response to time-varying resource demands. Experimental results on a heterogeneous cluster with varying hardware capabilities show that E-Ant with DVFS improves the overall energy savings for a synthetic workload from Microsoft by 23 and 17 percent compared to Fair Scheduler and Tarazu, respectively.
Autors: Dazhao Cheng;Xiaobo Zhou;Palden Lama;Mike Ji;Changjun Jiang;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jan 2018, volume: 29, issue:1, pages: 70 - 82
Publisher: IEEE
 
» Energy Efficient Adaptive Transmissions in Integrated Satellite-Terrestrial Networks With SER Constraints
Abstract:
Allowing frequency reuse between satellite and terrestrial networks, the integrated satellite-terrestrial network can spatially optimize the usage of scarce spectrum resource and is thus becoming one of the most promising infrastructures for future multimedia services. Taking the requirements of both efficiency and reliability in satellite communications into account, we propose an adaptive transmission scheme for the integrated network in this paper, where the satellite can communicate with the destination user either in direct mode or in cooperative mode. Specifically, we first investigate the symbol error rate (SER) performance of two transmission modes with co-channel interference under composite multipath/shadowing fading. Taking the derived SERs as constraints, we formulate the adaptive transmission scheme as an optimization problem with the objective of maximizing energy efficiency (EE) and discuss the trade-off among EE, spectral efficiency (SE), and SER. Furthermore, economic efficiency is also analyzed as a complementary performance measure to SE and EE. Simulation results show that the proposed scheme can increase the attainable EE of satellite communications, which indicates that we should choose the transmission mode adaptively according to different interfering scenarios and shadowing degrees, rather than adopting cooperative transmission aggressively.
Autors: Yuhan Ruan;Yongzhao Li;Cheng-Xiang Wang;Rui Zhang;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jan 2018, volume: 17, issue:1, pages: 210 - 222
Publisher: IEEE
 
» Energy Efficient Link-Delay Aware Routing in Wireless Sensor Networks
Abstract:
This paper investigates the problem of energy consumption in wireless sensor networks. Wireless sensor nodes deployed in harsh environment where the conditions change drastically suffer from sudden changes in link quality and node status. The end-to-end delay of each sensor node varies due to the variation of link quality and node status. On the other hand, the sensor nodes are supplied with limited energy and it is a great concern to extend the network lifetime. To cope with those problems, this paper proposes a novel and simple routing metric, predicted remaining deliveries (PRD), combining parameters, including the residual energy, link quality, end-to-end delay, and distance together to achieve better network performance. PRD assigns weights to individual links as well as end-to-end delay, so as to reflect the node status in the long run of the network. Large-scale simulation results demonstrate that PRD performs better than the widely used ETX metric as well as other two metrics devised recently in terms of energy consumption and end-to-end delay, while guaranteeing packet delivery ratio.
Autors: Xiaohan Lai;Xiaoyu Ji;Xinyan Zhou;Longdao Chen;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 837 - 848
Publisher: IEEE
 
» Energy Management System With PV Power Forecast to Optimally Charge EVs at the Workplace
Abstract:
This paper presents the design of an energy management system (EMS) capable of forecasting photovoltaic (PV) power production and optimizing power flows between PV system, grid, and battery electric vehicles (BEVs) at the workplace. The aim is to minimize charging cost while reducing energy demand from the grid by increasing PV self-consumption and consequently increasing sustainability of the BEV fleet. The developed EMS consists of two components: An autoregressive integrated moving average model to predict PV power production and a mixed-integer linear programming framework that optimally allocates power to minimize charging cost. The results show that the developed EMS is able to reduce charging cost significantly, while increasing PV self-consumption and reducing energy consumption from the grid. Furthermore, during a case study analogous to one repeatedly considered in the literature, i.e., dynamic purchase tariff and dynamic feed-in tariff, the EMS reduces charging cost by 118.44 and 427.45 in case of one and two charging points, respectively, when compared to an uncontrolled charging policy.
Autors: Dennis van der Meer;Gautham Ram Chandra Mouli;Laura Ramirez Elizondo;Pavol Bauer;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 311 - 320
Publisher: IEEE
 
» Energy Optimization for Data Allocation With Hybrid SRAM+NVM SPM
Abstract:
The gradually widening disparity in the speed of the CPU and memory has become a bottleneck for the development of chip multiprocessor (CMP) systems. Increasing penalties caused by frequent on-chip memory access have raised critical challenges in delivering high memory access performance with tight energy and latency budgets. To overcome the memory wall and energy wall issues, this paper adopts CMP systems with hybrid scratchpad memories (SPMs), which are configured from SRAM and nonvolatile memory. Based on this architecture, we propose two novel algorithms, i.e., energy-aware data allocation (EADA) and balancing data allocation to energy and write operations (BDAEW), to perform data allocation to different memories and task mapping to different cores, reducing energy consumption and latency. We evaluate the performance of our proposed algorithms by comparison with a parallel solution that is commonly used to solve data allocation and task scheduling problems. Experiments show the merits of the hybrid SPM architecture over the traditional pure memory system and the effectiveness of the proposed algorithms. Compared with the AGADA algorithm, the EADA and BDAEW algorithms can reduce energy consumption by 23.05% and 19.41%, respectively.
Autors: Yan Wang;Kenli Li;Jun Zhang;Keqin Li;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jan 2018, volume: 65, issue:1, pages: 307 - 318
Publisher: IEEE
 
» Energy Storage Arbitrage Under Day-Ahead and Real-Time Price Uncertainty
Abstract:
Electricity markets must match real-time supply and demand of electricity. With increasing penetration of renewable resources, it is important that this balancing is done effectively, considering the high uncertainty of wind and solar energy. Storing electrical energy can make the grid more reliable and efficient and energy storage is proposed as a complement to highly variable renewable energy sources. However, for investments in energy storage to increase, participating in the market must become economically viable for owners. This paper proposes a stochastic formulation of a storage owner's arbitrage profit maximization problem under uncertainty in day-ahead and real-time market prices. The proposed model helps storage owners in market bidding and operational decisions and in estimation of the economic viability of energy storage. Case study results on realistic market price data show that the novel stochastic bidding approach does significantly better than the deterministic benchmark.
Autors: Dheepak Krishnamurthy;Canan Uckun;Zhi Zhou;Prakash R. Thimmapuram;Audun Botterud;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 84 - 93
Publisher: IEEE
 
» Energy-Aware Virtual Machine Scheduling on Data Centers with Heterogeneous Bandwidths
Abstract:
Ethernet is the main choice of connectivity in data centers operating in clouds. The Ethernet standards body (IEEE 802.3) has generated Ethernet specifications with increasing transmission rates since its inception. As a result, it is observed that data centers with groups of physical hosts having heterogeneous bandwidths. In this paper, we present an energy-aware virtual machine’s scheduling method, taking into account this heterogeneity while aiming at energy efficiency. This method consists of two algorithms: one to determine to which physical hosts virtual machines should be allocated, and the other for the provision of bandwidth on physical hosts to virtual machines. Our study shows that, regarding energy savings for the studied scenarios, the presented method is comparable to other energy-aware methods in data centers with groups of machines with homogeneous settings, surpassing them in groups of machines with heterogeneous configurations, bringing improvements especially to data centers with heterogeneous bandwidths’ networks or to where restrictive SLAs are used for the provision of bandwidth to virtual machines.
Autors: Daniel Guimaraes Lago;Edmundo R. M. Madeira;Deep Medhi;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jan 2018, volume: 29, issue:1, pages: 83 - 98
Publisher: IEEE
 
» Energy-Efficient Composite Event Detection in Wireless Sensor Networks
Abstract:
Composite event detection is one of fundamental tasks for wireless sensor networks. In existing approaches, typically, a routing tree is used to enable information exchange among sensor nodes and collaborative detection of composite events. However, such a tree is not optimal in terms of energy efficiency, because the relations included in composite events have not been fully utilized. In this letter, we propose a new type of routing tree called event detection tree (EDT) to achieve energy-efficient composite event detection. EDT reduces the amount of data to be transmitted by aggregating data in to events, at the cost of an increased distance in the data transmission to achieve such aggregations. EDT achieves a tradeoff of them to minimize the overall energy consumption. Simulation results show that our approach outperforms existing approaches and yields energy savings of up to 20%.
Autors: Weiping Zhu;Jiannong Cao;Michel Raynal;
Appeared in: IEEE Communications Letters
Publication date: Jan 2018, volume: 22, issue:1, pages: 177 - 180
Publisher: IEEE
 
» Energy-Efficient Scheduling for Multiple Latency-Sensitive Bluetooth Low Energy Nodes
Abstract:
Energy-efficient scheduling in wireless embedded devices is a critical consideration due to limited energy supplies and the latency constraint of sensory data processing. Bluetooth low energy (BLE) is a low power solution that provides a user-defined connection interval parameter for extending the sleep time of BLE nodes. Instead of minimizing the values for this connection parameter to minimize latency, which can lead to excessive energy consumption, this paper presents a practical energy-efficient scheduling framework for multiple BLE devices having applications with latency constraints. First, we determine the required connection interval for a single BLE node with multi-rate sensing applications. Then, considering the scheduling issues caused by non-preemptive data transmission, we present an energy-efficient connection interval assignment for a sensor network with multiple BLE nodes to meet the latency constraints of sensing applications. Finally, based on the proposed connection interval determination, we propose a priority inversion awareness scheduler for the BLE master node to schedule all slave node transmissions in the network. Extensive experiments show that the proposed algorithms prolonged network lifetime by 235% compared with a simple pessimistic setting.
Autors: Jing-Ho Chen;Ya-Shu Chen;Yu-Lin Jiang;
Appeared in: IEEE Sensors Journal
Publication date: Jan 2018, volume: 18, issue:2, pages: 849 - 859
Publisher: IEEE
 
» Enhancement of Luminous Efficiency and Uniformity of CCT for Quantum Dot-Converted LEDs by Incorporating With ZnO Nanoparticles
Abstract:
ZnO nanoparticles were incorporated into quantum dot (QD)-silicone encapsulation materials of the light-emitting diodes (LEDs) to exploit their strong scattering effect, which were proved by the ZnO-only film experiment. The novel packaging scheme led to a decrease in the radiation flux because of the conversion-energy loss of QDs and backscattering of ZnO nanoparticles. Under the similar color coordinate, the luminous flux of the ZnO-incorporated QD-LED showed a 3.37% increase compared to the conventional structure. This was attributed to the scattering effect, which enhanced the utilization of blue light and the conversion of yellow light. And the angular-dependent correlated color temperature (CCT) deviation was reduced from 862 to 712 K in the range of −70° to 70°. Moreover, the CCT monotonically decreased, and the chromaticity coordinate steadily shifted to the yellow region as the amount of ZnO nanoparticles increased. Therefore, ZnO nanoparticles can be a favorable optical performance enhancer for the future generation of QD-converted LEDs.
Autors: Yong Tang;Zhi Li;Zong-Tao Li;Jia-Sheng Li;Shu-Dong Yu;Long-Shi Rao;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2018, volume: 65, issue:1, pages: 158 - 164
Publisher: IEEE
 
» Enhancing Detection of SSVEPs for a High-Speed Brain Speller Using Task-Related Component Analysis
Abstract:
Objective: This study proposes and evaluates a novel data-driven spatial filtering approach for enhancing steady-state visual evoked potentials (SSVEPs) detection toward a high-speed brain-computer interface (BCI) speller. Methods: Task-related component analysis (TRCA), which can enhance reproducibility of SSVEPs across multiple trials, was employed to improve the signal-to-noise ratio (SNR) of SSVEP signals by removing background electroencephalographic (EEG) activities. An ensemble method was further developed to integrate TRCA filters corresponding to multiple stimulation frequencies. This study conducted a comparison of BCI performance between the proposed TRCA-based method and an extended canonical correlation analysis (CCA)-based method using a 40-class SSVEP dataset recorded from 12 subjects. An online BCI speller was further implemented using a cue-guided target selection task with 20 subjects and a free-spelling task with 10 of the subjects. Results: The offline comparison results indicate that the proposed TRCA-based approach can significantly improve the classification accuracy compared with the extended CCA-based method. Furthermore, the online BCI speller achieved averaged information transfer rates (ITRs) of 325.33 ± 38.17 bits/min with the cue-guided task and 198.67 ± 50.48 bits/min with the free-spelling task. Conclusion: This study validated the efficiency of the proposed TRCA-based method in implementing a high-speed SSVEP-based BCI. Significance: The high-speed SSVEP-based BCIs using the TRCA method have great potential for various applications in communication and control.
Autors: Masaki Nakanishi;Yijun Wang;Xiaogang Chen;Yu-Te Wang;Xiaorong Gao;Tzyy-Ping Jung;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jan 2018, volume: 65, issue:1, pages: 104 - 112
Publisher: IEEE
 
» Entropy Bounds on Abelian Groups and the Ruzsa Divergence
Abstract:
Over the past few years, a family of interesting new inequalities for the entropies of sums and differences of random variables has been developed by Ruzsa, Tao, and others, motivated by analogous results in additive combinatorics. This paper extends these earlier results to the case of random variables taking values in or, more generally, in arbitrary locally compact and Polish abelian groups. We isolate and study a key quantity, the Ruzsa divergence between two probability distributions, and we show that its properties can be used to extend the earlier inequalities to the present general setting. The new results established include several variations on the theme that the entropies of the sum and the difference of two independent random variables severely constrain each other. Although the setting is quite general, the results are already of interest (and new) for random vectors in . In that special case, we discuss quantitative bounds for the stability of the equality conditions in the entropy power inequality, a reverse entropy power inequality for log-concave random vectors, an information-theoretic analog of the Rogers–Shephard inequality for convex bodies, and consequences of some of our results to determinant inequalities for sums of positive-definite matrices. Moreover, by considering various multiplicative subgroups of the complex plane, one obtains new inequalities for the differential entropies of products and ratios of nonzero, complex-valued random variables.
Autors: Mokshay Madiman;Ioannis Kontoyiannis;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2018, volume: 64, issue:1, pages: 77 - 92
Publisher: IEEE
 
» Equivalent Surface Impedance-Based Mixed Potential Integral Equation Accelerated by Optimized $cal {H}$ -Matrix for 3-D Interconnects
Abstract:
The equivalent surface impedance (ESI)-based mixed potential integral equation (MPIE) is proposed in this paper for parameter extraction of 3-D interconnects. Boundary integral equations (BIEs) describing the conductor region and the nonconductor region are utilized to derive the ESI model, which incorporates with an MPIE to simplify the electromagnetic simulation. For large-scale problems, the solution of MPIE is accelerated by the hierarchical matrix (-matrix) algorithm. Since the interconnect problems usually have multiple ports, the method of moments discretization of MPIE leads to the matrix equation with multiple right-hand sides, which is efficiently solved by the -LU-based direct solution. Procedures for -matrix are optimized to improve the overall efficiency. The proposed method to optimize -matrix benefits both the -matrix construction and the -LU procedures. The complexities of the CPU time and memory cost for the construction of the optimized -matrix are of , and the complexity for the direct -LU solution is of . Numerical results demonstrate that the proposed method is both acc- rate and efficient in a broadband frequency, which is suitable for modeling of 3-D interconnects and on-chip passive structures.
Autors: Yu Zhao;Junfa Mao;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 22 - 34
Publisher: IEEE
 
» Equivalent-Time Direct-Sampling Impulse-Radio Radar With Rotatable Cyclic Vernier Digital-to-Time Converter for Wireless Sensor Network Localization
Abstract:
This paper presents a rotatable cyclic Vernier digital-to-time converter (DTC) with 1.8 ps timing resolution on an 80 ns time scale. The proposed DTC features high timing resolution, and can be utilized in beam-steering arrays, which is infeasible for ordinary Vernier DTCs. The proposed DTC was implemented within a passive time-equivalent direct-sampling ultra-wideband impulse-radio radar system and was fabricated in 65 nm CMOS technology. This radar system is capable of quantizing direct-sampled impulse waveforms to provide full degrees of freedom for backend digital signal processing. The measured differential nonlinearity/integral nonlinearity of the DTC was +4.6/−3 and 12.4/−9.4 where the LSB was 1.8 ps, and the total power consumption was 133 mW. Also, a new method for localization between wireless sensor nodes of equivalent-time direct-sampling radar is presented in this paper; this method can theoretically achieve resolution as high as that of regular radar.
Autors: Shao-Ting Tseng;Hao-Chung Chou;Bo-Syun Hu;Yu-Hsien Kao;Yuan-Hao Huang;Ta-Shun Chu;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 485 - 508
Publisher: IEEE
 
» ERFNet: Efficient Residual Factorized ConvNet for Real-Time Semantic Segmentation
Abstract:
Semantic segmentation is a challenging task that addresses most of the perception needs of intelligent vehicles (IVs) in an unified way. Deep neural networks excel at this task, as they can be trained end-to-end to accurately classify multiple object categories in an image at pixel level. However, a good tradeoff between high quality and computational resources is yet not present in the state-of-the-art semantic segmentation approaches, limiting their application in real vehicles. In this paper, we propose a deep architecture that is able to run in real time while providing accurate semantic segmentation. The core of our architecture is a novel layer that uses residual connections and factorized convolutions in order to remain efficient while retaining remarkable accuracy. Our approach is able to run at over 83 FPS in a single Titan X, and 7 FPS in a Jetson TX1 (embedded device). A comprehensive set of experiments on the publicly available Cityscapes data set demonstrates that our system achieves an accuracy that is similar to the state of the art, while being orders of magnitude faster to compute than other architectures that achieve top precision. The resulting tradeoff makes our model an ideal approach for scene understanding in IV applications. The code is publicly available at: https://github.com/Eromera/erfnet
Autors: Eduardo Romera;José M. Álvarez;Luis M. Bergasa;Roberto Arroyo;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2018, volume: 19, issue:1, pages: 263 - 272
Publisher: IEEE
 
» Error-Free Operation in a Hybrid-Silicon Quantum Dot Comb Laser
Abstract:
We investigate amplitude noise in a wafer-bonded quantum dot laser on silicon. Error-free operation at room temperature and under continuous current injection in the three highest-power channels is observed with a signal-to-noise ratio of 11.5 dB or larger. These devices are attractive candidates as an optical engine for interconnects in next-generation data centers and exascale computers.
Autors: Geza Kurczveil;M. Ashkan Seyedi;Di Liang;Marco Fiorentino;Raymond G. Beausoleil;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2018, volume: 30, issue:1, pages: 71 - 74
Publisher: IEEE
 
» Essential Measurements for Finite Element Simulations of Magnetostrictive Materials
Abstract:
We discuss which magnetoelastic material properties are essential to measure in order to model magnetostrictive materials in finite element simulations. We show knowing the magnetic constitutive relation is sufficient, if the elastic behavior without magnetic field is known a priori. We neglect hysteresis, and our starting point is to express the effect of mechanical deformation on the magnetic constitutive relation with a small strain tensor and magnetic flux density. It follows that the (energetic) state of a magnetostrictive material is independent of its history. Then, a certain choice of history allows us to keep magnetism and elasticity distinct. We demonstrate with open source software Elmer, how one can set up such magnetoelastic simulations. These simulations rely on data obtained from magnetostrictive measurements. Finally, it is discussed how a measurement setup and the finite element model should be combined in order to verify the approach with experiments.
Autors: Arto Poutala;Tuomas Kovanen;Lauri Kettunen;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2018, volume: 54, issue:1, pages: 1 - 7
Publisher: IEEE
 
» Estimating Error Covariance and Correlation Region in UV Irradiance Data Fusion by Combining TOMS-OMI and UVMRP Ground Observations
Abstract:
Surface ultraviolet (UV) observations can be obtained from satellite or ground observations. This paper uses one data fusion technique (similar to Kalman filter) to combine the advantages from both sources of observations, aiming at achieving a better estimate of surface UV. In this paper, new mathematical methods and algorithms were developed to estimate the error covariance and correlation region, which are the most important components in this data fusion technique. This technique was applied to the satellite data from the Total Ozone Mapping Spectrometer (TOMS)-Ozone Monitoring Instrument (OMI) combined with ground measurements from UV-B Monitoring and Research Program (UVMRP) within the region of continental U.S. from 2005 to 2015. Numerical experiments showed that the technique is effective, and TOMS-OMI data were improved by combining UVMRP data. In addition, the innovative ensemble-based method is generic and can be applied to other fields for data fusion/assimilation.
Autors: Zhibin Sun;John Davis;Wei Gao;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jan 2018, volume: 56, issue:1, pages: 355 - 370
Publisher: IEEE
 
» EUV lithography finally ready for fabs
Abstract:
"A fab is like an iceberg," someone tells me. I can't tell who because we're all covered head to toe in clean-room garb. A tour of GlobalFoundries' Fab 8 in Malta, N.Y., certainly reinforces that analogy: We've just come up from the "sub-fab," the 10 meters of vertical space under the floor, where pipes and wires snake down from each semiconductor-manufacturing tool above to a set of automated chemical handlers, water analyzers, power conditioners, and-in the case of the unit I've come to see-kilowatt-class lasers.
Autors: Samuel K. Moore;
Appeared in: IEEE Spectrum
Publication date: Jan 2018, volume: 55, issue:1, pages: 46 - 48
Publisher: IEEE
 
» EVA: Visual Analytics to Identify Fraudulent Events
Abstract:
Financial institutions are interested in ensuring security and quality for their customers. Banks, for instance, need to identify and stop harmful transactions in a timely manner. In order to detect fraudulent operations, data mining techniques and customer profile analysis are commonly used. However, these approaches are not supported by Visual Analytics techniques yet. Visual Analytics techniques have potential to considerably enhance the knowledge discovery process and increase the detection and prediction accuracy of financial fraud detection systems. Thus, we propose EVA, a Visual Analytics approach for supporting fraud investigation, fine-tuning fraud detection algorithms, and thus, reducing false positive alarms.
Autors: Roger A. Leite;Theresia Gschwandtner;Silvia Miksch;Simone Kriglstein;Margit Pohl;Erich Gstrein;Johannes Kuntner;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 330 - 339
Publisher: IEEE
 
» Evaluation of Electromagnetic Exposure During 85 kHz Wireless Power Transfer for Electric Vehicles
Abstract:
The external fields in the proximity of electric vehicle (EV) wireless power transfer (WPT) systems requiring high power may exceed the limits of international safety guidelines. This paper presents dosimetric results of an 85 kHz WPT system for EVs. A WPT system for charging EVs is designed and dosimetry for the system is evaluated for various exposure scenarios: a human body in front of the WPT system without shielding, with shielding, with alignment and misalignment between transmitter and receiver, and with a metal plate on the system for vehicle mimic floor pan. The minimum accessible distances in compliance are investigated for various transmitting powers. The maximum allowable transmitting power is also investigated with the limits of international safety guidelines and the dosimetric results.
Autors: Sangwook Park;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jan 2018, volume: 54, issue:1, pages: 1 - 8
Publisher: IEEE
 
» Event-Based Supervisory Control for Energy Efficient Manufacturing Systems
Abstract:
It becomes more and more critical for manufacturing enterprises to improve energy efficiency because of the escalating energy prices, increasing global competitions, and more rigorous government regulations. In this paper, a systematic method is developed to improve the energy efficiency of a multistage manufacturing system through production control. The method aims at reducing energy consumption with minimal negative impact on production. We start from the analysis of system dynamics and develop quantitative methods to estimate energy saving opportunities. A supervisory control algorithm is developed to improve system energy efficiency by periodically taking the saving opportunities. Simulation case studies are performed to validate the effectiveness of the control algorithm.

Note to Practitioners—Manufacturing systems are facing increasing pressure to reduce energy consumption, as global competition, sustainability, and green processes are becoming more prevalent. Although most of the research efforts on manufacturing energy saving have focused on developing individual energy efficient machines, it can be more cost-effective to improve energy efficiency through better control of the energy usage of the whole production system. Therefore, this paper presents a systematic method to improve system energy efficiency with a minimal negative impact on production. This paper continues the work by Chang et al. by extending the scope of energy saving opportunity theory from serial production systems to general serial–parallel production systems. It also develops analytical methods based on Markov chain models to estimate the energy saving opportunity accurately.

Autors: Yang Li;Qing Chang;Jun Ni;Michael P. Brundage;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2018, volume: 15, issue:1, pages: 92 - 103
Publisher: IEEE
 
» EventThread: Visual Summarization and Stage Analysis of Event Sequence Data
Abstract:
Event sequence data such as electronic health records, a person's academic records, or car service records, are ordered series of events which have occurred over a period of time. Analyzing collections of event sequences can reveal common or semantically important sequential patterns. For example, event sequence analysis might reveal frequently used care plans for treating a disease, typical publishing patterns of professors, and the patterns of service that result in a well-maintained car. It is challenging, however, to visually explore large numbers of event sequences, or sequences with large numbers of event types. Existing methods focus on extracting explicitly matching patterns of events using statistical analysis to create stages of event progression over time. However, these methods fail to capture latent clusters of similar but not identical evolutions of event sequences. In this paper, we introduce a novel visualization system named EventThread which clusters event sequences into threads based on tensor analysis and visualizes the latent stage categories and evolution patterns by interactively grouping the threads by similarity into time-specific clusters. We demonstrate the effectiveness of EventThread through usage scenarios in three different application domains and via interviews with an expert user.
Autors: Shunan Guo;Ke Xu;Rongwen Zhao;David Gotz;Hongyuan Zha;Nan Cao;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 56 - 65
Publisher: IEEE
 
» Exact Timing Analysis for Asynchronous Systems
Abstract:
Analyzing the timing properties of asynchronous systems is essential for characterizing their performance and power. Previous work on timing showed that such systems under and-causality and fixed delay exhibit periodicity properties. We give a different graph-based rigorous proof of the exact timing behavior of more general classes of such systems, and conclude their exact periodicity property, where each of the signal transition will occur with the same period after finite occurrences. We established our results under weaker assumption about system connectivity/topology, and this paper provides the theoretical foundation, for the exact periodicity property to be applied and exploited in circuits containing a combination of synchronous and asynchronous components. We provide simulation-based results for several typical asynchronous circuit topologies to quantify this time period in practical circuits. We also provide an extension of our analysis and methods to the case of bounded delay systems. A key result that is a consequence of our analysis is that asynchronous circuits can be integrated with synchronous logic via a metastability-free interface, thereby eliminating the high-overhead synchronizers when an asynchronous circuit is fully surrounded by synchronous logic.
Autors: Wenmian Hua;Rajit Manohar;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jan 2018, volume: 37, issue:1, pages: 203 - 216
Publisher: IEEE
 
» Experimental ${g}_{m}/{I}_{{D}}$ Invariance Assessment for Asymmetric Double-Gate FDSOI MOSFET
Abstract:
Transconductance efficiency () is an essential design synthesis tool for low-power analog and RF applications. In this paper, the invariance of versus normalized drain current curve is analyzed in an asymmetric double-gate (DG) fully depleted MOSFET. This paper studies the breakdown of this invariance versus back-gate voltage, transistor length, temperature, drain-to-source voltage, and process variations. The unforeseeable invariance is emphasized by measurements of a commercial 28-nm ultrathin body and box fully depleted Silicon-on-Insulator (SOI) (FDSOI) CMOS technology, thus supporting the -based design methodologies usage in DG FDSOI transistors sizing.
Autors: Salim El Ghouli;Denis Rideau;Frederic Monsieur;Patrick Scheer;Gilles Gouget;André Juge;Thierry Poiroux;Jean-Michel Sallese;Christophe Lallement;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2018, volume: 65, issue:1, pages: 11 - 18
Publisher: IEEE
 
» Exploiting Parallelism for Access Conflict Minimization in Flash-Based Solid State Drives
Abstract:
Solid state drives (SSDs) have been widely deployed in personal computers, data centers, and cloud storages. In order to improve performance, SSDs are usually constructed with a number of channels with each channel connecting to a number of nand flash chips, each flash chip consisting of multiple dies and each die containing multiple planes. Based on this parallel architecture, I/O requests are potentially able to access parallel units simultaneously. Despite the rich parallelism offered by the parallel architecture, recent studies show that the utilization of flash parallel units is seriously low. This paper shows that the low parallel unit utilization is highly caused by the access conflict among I/O requests. In this paper, we propose parallel issue queueing (PIQ), a novel I/O scheduler at the host systems. PIQ groups I/O requests without conflicts into the same batch and I/O requests with conflicts into different batches. Hence, the multiple I/O requests in one batch can be fulfilled simultaneously by exploiting the rich parallelism of SSDs. Extensive experimental results show that PIQ delivers significant performance improvement especially for the applications which have heavy access conflicts.
Autors: Congming Gao;Liang Shi;Cheng Ji;Yejia Di;Kaijie Wu;Chun Jason Xue;Edwin H.-M. Sha;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jan 2018, volume: 37, issue:1, pages: 168 - 181
Publisher: IEEE
 
» Exploring 3-D Printing for New Applications: Novel Inkjet- and 3-D-Printed Millimeter-Wave Components, Interconnects, and Systems
Abstract:
This article outlines a number of inkjet-/threedimensional (3-D)-printed prototypes of RF and millimeter-wave (mmW) components, interconnects, and systems. We pay special attention to the major challenges related to applying current multidimensional printing technologies to the fabrication of flexible multichip modules (MCMs) and high-performance mmW components.
Autors: Ryan Bahr;Bijan Tehrani;Manos M. Tentzeris;
Appeared in: IEEE Microwave Magazine
Publication date: Jan 2018, volume: 19, issue:1, pages: 57 - 66
Publisher: IEEE
 
» Exploring Flexibility of DRX in LTE/LTE-A: Design of Dynamic and Adjustable DRX
Abstract:
Only two types of sleep cycles with two fixed sleep periods are defined in the standard of the discontinuous reception (DRX) mechanism in LTE/LTE-A. Explicitly, such a DRX mechanism is simple but lacks flexibility. To provide flexibility, two types of dynamic and adjustable DRX (DADRX) mechanisms are proposed and investigated in this paper. The first type of DADRX extends the number of types of sleep cycles through adding different pairs of sleep cycles with different sleep periods gradually. As for the second type of DADRX, it fixes the total number of types of sleep cycles like the first-type DADRX but further employs a set of level expanding probabilities to control probabilistically the possible pairs of sleep cycles that can be reached. To enable the analytical calculation, performance metrics for the proposed DADRX mechanisms are acquired, including average response delay and average long-term power consumption. Via both analytical and simulation approaches, we investigate the dynamics of performance for the proposed DADRX mechanisms extensively. We successfully show that these two proposed mechanisms can exhibit much more flexibility than the closely related mechanisms in the literature.
Autors: Huei-Wen Ferng;Teng-Hui Wang;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jan 2018, volume: 17, issue:1, pages: 99 - 112
Publisher: IEEE
 
» Exploring Multivariate Event Sequences Using Rules, Aggregations, and Selections
Abstract:
Multivariate event sequences are ubiquitous: travel history, telecommunication conversations, and server logs are some examples. Besides standard properties such as type and timestamp, events often have other associated multivariate data. Current exploration and analysis methods either focus on the temporal analysis of a single attribute or the structural analysis of the multivariate data only. We present an approach where users can explore event sequences at multivariate and sequential level simultaneously by interactively defining a set of rewrite rules using multivariate regular expressions. Users can store resulting patterns as new types of events or attributes to interactively enrich or simplify event sequences for further investigation. In Eventpad we provide a bottom-up glyph-oriented approach for multivariate event sequence analysis by searching, clustering, and aligning them according to newly defined domain specific properties. We illustrate the effectiveness of our approach with real-world data sets including telecommunication traffic and hospital treatments.
Autors: Bram C.M. Cappers;Jarke J. van Wijk;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 532 - 541
Publisher: IEEE
 
» Extended Lifetime In Vivo Pulse Stimulated Ultrasound Imaging
Abstract:
An on-demand long-lived ultrasound contrast agent that can be activated with single pulse stimulated imaging (SPSI) has been developed using hard shell liquid perfluoropentane filled silica 500-nm nanoparticles for tumor ultrasound imaging. SPSI was tested on LnCAP prostate tumor models in mice; tumor localization was observed after intravenous (IV) injection of the contrast agent. Consistent with enhanced permeability and retention, the silica nanoparticles displayed an extended imaging lifetime of 3.3±1 days (mean±standard deviation). With added tumor specific folate functionalization, the useful lifetime was extended to 12 ± 2 days; in contrast to ligand-based tumor targeting, the effect of the ligands in this application is enhanced nanoparticle retention by the tumor. This paper demonstrates for the first time that IV injected functionalized silica contrast agents can be imaged with an in vivo lifetime ~500 times longer than current microbubble-based contrast agents. Such functionalized long-lived contrast agents may lead to new applications in tumor monitoring and therapy.
Autors: James Wang;Christopher V. Barback;Casey N. Ta;Joi Weeks;Natalie Gude;Robert F. Mattrey;Sarah L. Blair;William C. Trogler;Hotaik Lee;Andrew C. Kummel;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Jan 2018, volume: 37, issue:1, pages: 222 - 229
Publisher: IEEE
 
» Extracting and Retargeting Color Mappings from Bitmap Images of Visualizations
Abstract:
Visualization designers regularly use color to encode quantitative or categorical data. However, visualizations “in the wild” often violate perceptual color design principles and may only be available as bitmap images. In this work, we contribute a method to semi-automatically extract color encodings from a bitmap visualization image. Given an image and a legend location, we classify the legend as describing either a discrete or continuous color encoding, identify the colors used, and extract legend text using OCR methods. We then combine this information to recover the specific color mapping. Users can also correct interpretation errors using an annotation interface. We evaluate our techniques using a corpus of images extracted from scientific papers and demonstrate accurate automatic inference of color mappings across a variety of chart types. In addition, we present two applications of our method: automatic recoloring to improve perceptual effectiveness, and interactive overlays to enable improved reading of static visualizations.
Autors: Jorge Poco;Angela Mayhua;Jeffrey Heer;
Appeared in: IEEE Transactions on Visualization and Computer Graphics
Publication date: Jan 2018, volume: 24, issue:1, pages: 637 - 646
Publisher: IEEE
 
» Extraction of the Built-in Potential for Organic Solar Cells From Current–Voltage Characteristics
Abstract:
The built-in potential () of an organic diode and solar cell is an important parameter that decides the rectification behavior of organic diodes and affects the open circuit voltage and thereby the efficiency of organic solar cells. In this paper, we propose a physics-based model and an experimental method to extract from current density–voltage (–) characteristics. The proposed model is developed by solving the carrier transport and the continuity equations to obtain the analytic equations for charge carrier profile and current density. The proposed method is thoroughly verified using numerical simulation results. Applicability of this method on experimental results is further validated for poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester solar cells. Finally, is extracted from dark – characteristics of fabricated devices.
Autors: Prashanth Kumar Manda;Saranya Ramaswamy;Soumya Dutta;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jan 2018, volume: 65, issue:1, pages: 184 - 190
Publisher: IEEE
 
» Extremality Between Symmetric Capacity and Gallager’s Reliability Function $E_{0}$ for Ternary-Input Discrete Memoryless Channels
Abstract:
This paper examines the exact ranges between the symmetric capacity and Gallager’s reliability function for ternary-input discrete memoryless channels (T-DMCs) under a uniform input distribution. We first derive the two extremal ternary-input strongly symmetric channels taking the maximum and minimum values of the function among all ternary-input strongly symmetric channels with a fixed capacity. Extending the results of ternary-input strongly symmetric channels, we second derive the exact ranges between capacity and the function for ternary-input Gallager-symmetric channels. We third show that the exact ranges between the symmetric capacity and the function of T-DMCs coincide with the ranges of ternary-input Gallager-symmetric channels. In particular, we identify the extremal channels taking the maximum and minimum of among all T-DMCs with a fixed symmetric capacity. As applications of the results, we describe some bounds of error exponents for T-DMCs with a fixed symmetric capacity.
Autors: Yuta Sakai;Ken-ichi Iwata;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2018, volume: 64, issue:1, pages: 163 - 191
Publisher: IEEE
 
» Fabrication and Performance of a Miniaturized and Integrated Endoscope Ultrasound Convex Array for Digestive Tract Imaging
Abstract:
Objective: this work presents the design, fabrication, and testing of a miniaturized and integrated ultrasound endoscope for use as an in situ digestive diagnostic device to facilitate real-time ultrasound guidance of intervention treatments. Methods: we designed an optimal structure to integrate an auto-focus 5-megapixel camera module with an 8-MHz, 64-element curvilinear ultrasonic array in one miniaturized package. A novel three-axis auto-focusing voice coil motor (VCM) was designed and manufactured for the camera module to move the lens position for auto-focusing and to adjust the lens tilt. Results: the results showed that the array had a center frequency of 8.09 MHz and a –6-dB fractional bandwidth of 83%. At the center frequency, the two-way insertion loss was 40.6 dB. Endoscopic ultrasound imaging demonstrated satisfactory performance for imaging an anthropomorphic phantom of the esophagus. By slightly adjusting the tilt angle of the optical axis of the lens, the optical image captured by the auto-focusing lens obtained improved definition regardless of changes in the view angle of the camera with respect to the objects being captured. Conclusion: the integrated convex ultrasound endoscope, possessing minimal size, improved optical imaging definition, and good ultrasound imaging performance, can become a useful tool in digestive tract imaging. Significance: the miniaturized and integrated convex ultrasound endoscope can facilitate real-time ultrasound intervention guidance, reducing risks associated with the operation.
Autors: Jue Peng;Xiaojian Peng;Hu Tang;Xiaozhen Li;Ruimin Chen;Yang Li;Tianfu Wang;Siping Chen;K. Kirk Shung;Qifa Zhou;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jan 2018, volume: 65, issue:1, pages: 140 - 148
Publisher: IEEE
 
» Fabrication of Bragg Gratings in Random Air-Line Clad Microstructured Optical Fiber
Abstract:
Fiber Bragg gratings (FBGs) are written using an infrared (IR) femtosecond laser and a phase mask into pure silica microstructured optical fiber having a cladding region comprised of random air-lines (RAL). Scanning electron microscopy measurements of the IR irradiated RAL fiber samples shows the presence of subwavelength nanograting structures associated with thermally stable type II Bragg gratings. High temperature annealing testing shows that although the RAL FBGs have a high degree of stability even at 1000 °C, they are less stable than similar FBGs made in single mode telecom fiber (SMF-28).
Autors: Stephen J. Mihailov;Cyril Hnatovsky;Dan Grobnic;Kevin Chen;Ming-Jun Li;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2018, volume: 30, issue:2, pages: 209 - 212
Publisher: IEEE
 
» Fast AC Power Flow Optimization Using Difference of Convex Functions Programming
Abstract:
An effective means for analyzing the impact of novel operating schemes on power systems is time-domain simulation, for example, for investigating optimization-based curtailment of renewables to alleviate voltage violations. Traditionally, interior-point methods are used for solving the non-convex AC optimal power flow (OPF) problems arising in this type of simulation. This paper presents an alternative algorithm that better suits the simulation framework, because it can more effectively be warm started, has linear computational and memory complexity in the problem size per iteration and globally converges to Karush–Kuhn–Tucker (KKT) points with a linear rate if they exist. The algorithm exploits a difference-of-convex-functions reformulation of the OPF problem, which can be performed effectively. Numerical results are presented comparing the method to state-of-the-art OPF solver implementations in MATPOWER, leading to significant speedups compared to the latter for smaller systems and comparable performance for larger cases.
Autors: Sandro Merkli;Alexander Domahidi;Juan L. Jerez;Manfred Morari;Roy S. Smith;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 363 - 372
Publisher: IEEE
 
» Fast Amplitude Estimation of Harmonics Using Undecimated Wavelet Packet Transform and Its Hardware Implementation
Abstract:
Accurate and fast estimation of time-varying harmonics are essential requirements for online monitoring, analysis, and control of electrical power system. This paper presents a fast algorithm based on the undecimated wavelet packet transform (UWPT) to estimate the amplitude of fundamental and harmonic components of stationary as well as a time-varying power signal. The UWPT uses only one cycle of the fundamental frequency for precise measurement of time-varying harmonics while their amplitude has been determined accurately utilizing the time-invariant property of the UWPT. The robustness and accuracy of the proposed technique have been investigated on synthetic as well as experimental test signals using MATLAB tool. Further, the UWPT algorithm has also been implemented on the Xilinx Virtex-6 FPGA ML-605 board, using XSG/ISE design suite 14.2 and its performance, in terms of hardware accuracy, resource utilization as well as timing requirements have been tested using the experimental test signal.
Autors: Vinay K. Tiwari;Amod C. Umarikar;Trapti Jain;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jan 2018, volume: 67, issue:1, pages: 65 - 77
Publisher: IEEE
 
» Fast and Stable Signal Deconvolution via Compressible State-Space Models
Abstract:
Objective: Common biological measurements are in the form of noisy convolutions of signals of interest with possibly unknown and transient blurring kernels. Examples include EEG and calcium imaging data. Thus, signal deconvolution of these measurements is crucial in understanding the underlying biological processes. The objective of this paper is to develop fast and stable solutions for signal deconvolution from noisy, blurred, and undersampled data, where the signals are in the form of discrete events distributed in time and space. Methods: We introduce compressible state-space models as a framework to model and estimate such discrete events. These state-space models admit abrupt changes in the states and have a convergent transition matrix, and are coupled with compressive linear measurements. We consider a dynamic compressive sensing optimization problem and develop a fast solution, using two nested expectation maximization algorithms, to jointly estimate the states as well as their transition matrices. Under suitable sparsity assumptions on the dynamics, we prove optimal stability guarantees for the recovery of the states and present a method for the identification of the underlying discrete events with precise confidence bounds. Results: We present simulation studies as well as application to calcium deconvolution and sleep spindle detection, which verify our theoretical results and show significant improvement over existing techniques. Conclusion: Our results show that by explicitly modeling the dynamics of the underlying signals, it is possible to construct signal deconvolution solutions that are scalable, statistically robust, and achieve high temporal resolution. Significance: Our proposed methodology provides a framework for modeling and deconvolution of noisy, blurred, and undersampled measurements in a fast and stable fashion, with potential application to a wide range - f biological data.
Autors: Abbas Kazemipour;Ji Liu;Krystyna Solarana;Daniel A. Nagode;Patrick O. Kanold;Min Wu;Behtash Babadi;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jan 2018, volume: 65, issue:1, pages: 74 - 86
Publisher: IEEE
 
» Fast Correction of Network Parameter Errors
Abstract:
In this letter, a fast network parameter error correction scheme is proposed based on recent findings on parameter error identification. Compared to the widely applied augmented state estimation approach, it is computationally very efficient and numerically stable, and requires very modest coding effort. Simulation results in the New England power system show that it produces reliable results in the presence of both strongly correlated errors and Gaussian measurement noise.
Autors: Yuzhang Lin;Ali Abur;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 1095 - 1096
Publisher: IEEE
 
» Fast Dynamic Fault Tree Analysis by Model Checking Techniques
Abstract:
This paper presents a new state-space generation approach for dynamic fault trees (DFTs) that exploits several successful reduction techniques from the field of model checking. The key idea is to aggressively exploit the DFT structure—detecting symmetries, spurious nondeterminism, and don't cares. Benchmarks show a gain of more than two orders of magnitude in terms of state-space generation and analysis time. This fast, scalable approach is complemented by an approximative technique that determines bounds on DFT measures by a partial state-space generation. This is shown to yield another order of magnitude gain while guaranteeing tight error bounds.
Autors: Matthias Volk;Sebastian Junges;Joost-Pieter Katoen;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Jan 2018, volume: 14, issue:1, pages: 370 - 379
Publisher: IEEE
 
» Fast Evaluation of Commutation Failure Risk in Multi-Infeed HVDC Systems
Abstract:
This paper presents a fast and reliable method to evaluate risk of single or multiple commutation failures for multi-infeed HVDC systems following faults occurring at the receiving-end ac system. First, a fast calculation method of multi-infeed interaction factor, describing the interactivity and mutual impact between two inverter AC buses on is proposed. It is then refined to being the AC–DC system voltage interaction factor (ADVIF) to represent the relationship in bus voltages between inverter and AC buses at the re-ceiving-end systems. Then, a critical AC–DC system voltage interaction factor (CADVIF) based on the minimum extinction angle criteria is proposed. By calculating and comparing ADVIFs and CADVIFs, which can be obtained quickly, it is possible to identify AC buses that, if a fault occurs, would cause commutation failures at one or more HVDC systems. The validity and accuracy of the proposed approach are demonstrated by comparing with simulations results using a two-infeed HVDC test system and an actual large power grid.
Autors: Yao Shao;Yong Tang;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 646 - 653
Publisher: IEEE
 
» Fast Linear Quaternion Attitude Estimator Using Vector Observations
Abstract:
As a key problem for multisensor attitude determination, Wahba's problem has been studied for almost 50 years. Different from existing methods, this paper presents a novel linear approach to solve this problem. We name the proposed method the fast linear attitude estimator (FLAE) because it is faster than known representative algorithms. The original Wahba's problem is extracted to several 1-D equations based on quaternions. They are then investigated with pseudoinverse matrices establishing a linear solution to n-D equations, which are equivalent to the conventional Wahba's problem. To obtain the attitude quaternion in a robust manner, an eigenvalue-based solution is proposed. Symbolic solutions to the corresponding characteristic polynomial are derived, showing higher computation speed. Simulations are designed and conducted using test cases evaluated by several classical methods, e.g., Shuster's quaternion estimator, Markley's singular value decomposition method, Mortari's second estimator of the optimal quaternion, and some recent representative methods, e.g., Yang's analytical method and Riemannian manifold method. The results show that FLAE generates attitude estimates as accurate as that of several existing methods, but consumes much less computation time (about 50% of the known fastest algorithm). Also, to verify the feasibility in embedded application, an experiment on the accelerometer-magnetometer combination is carried out where the algorithms are compared via C++ programming language. An extreme case is finally studied, revealing a minor improvement that adds robustness to FLAE, inspired by Cheng et al.
Autors: Jin Wu;Zebo Zhou;Bin Gao;Rui Li;Yuhua Cheng;Hassen Fourati;
Appeared in: IEEE Transactions on Automation Science and Engineering
Publication date: Jan 2018, volume: 15, issue:1, pages: 307 - 319
Publisher: IEEE
 
» Fast Near-Optimal Heuristic for the Short-Term Hydro-Generation Planning Problem
Abstract:
Short-term hydro-generation planning can be efficiently modeled as a mixed integer linear program (MILP). Depending on the size of the system and the time horizon, the resulting MILP may be too large to be solved in reasonable time with commercial solvers. This paper presents a three-phase approach based on price decomposition that yields quickly near-optimal solutions to large-scale real-world instances. For any partition of the production system into subsystems, the first phase solves a linear program to estimate the marginal cost of electricity in each subsystem. The second phase solves local MILPs corresponding to each subsystem, and gives a solution that is almost feasible. The final phase slightly perturbs the solution to obtain a feasible solution that is proven to be near-optimal. Our method is tested on real instances corresponding to Hydro-Québec's production system.
Autors: Alexia Marchand;Michel Gendreau;Marko Blais;Grégory Emiel;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 227 - 235
Publisher: IEEE
 
» Fast Online Tracking With Detection Refinement
Abstract:
Most of the existing multiple object tracking (MOT) methods employ the tracking-by-detection framework. Among them, the min-cost network flow optimization techniques become the most popular and standard ones. In these methods, the graph structure models the MOT problem and finds the optimal flow in a connected graph of detections to encode the accurate track trajectories. However, the existing network flow is not suitable for directly online tracking, where the tracking results depend too much on the initial detections. To solve these problems, we present a fast online MOT algorithm by introducing the minimum output sum of squared error filter. The proposed method can adaptively refine the tracking targets according to the proposed rules of correcting the detection mistakes. Furthermore, we introduce an alternative targets hypotheses to reduce the dependence on detections and adaptively refine the object detection boxes. The experimental results on the MOT 2015 benchmark demonstrate that our method achieves comparable or even better results than previous approaches.
Autors: Jianbing Shen;Dajiang Yu;Leyao Deng;Xingping Dong;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2018, volume: 19, issue:1, pages: 162 - 173
Publisher: IEEE
 
» Fast Quantitative Microwave Imaging With Scattered-Power Maps
Abstract:
A new direct-inversion method, scattered-power mapping (SPM), for fast quantitative microwave imaging is introduced. It builds on a recently proposed inversion strategy that demonstrated quantitative direct reconstruction with experimentally acquired system point-spread functions. In comparison with this initial work, SPM features a drastic improvement in the computational time along with reduced number of calibration measurements. Moreover, SPM is versatile allowing a forward model of scattering cast either as a linearized Born model or as a Rytov model. SPM is intended as a tool to solve weak-scattering problems or as a linear-inversion module within nonlinear iterative reconstruction.
Autors: Denys S. Shumakov;Natalia K. Nikolova;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 439 - 449
Publisher: IEEE
 
» Fast Stability Scanning for Future Grid Scenario Analysis
Abstract:
Future grid scenario analysis requires a major departure from conventional power system planning, where only a handful of most critical conditions is typically analyzed. To capture the interseasonal and temporal variations in the renewable generation of a future grid scenario necessitates the use of computationally intensive time-series analysis. In this paper, we propose a framework for fast stability scanning of future grid scenarios using an improved feature selection and self-adaptive PSO-k-means clustering algorithm. To achieve the computational speedup, the stability analysis is performed only on small number of representative cluster centroids instead of on the full set of operating conditions. As a case study, we perform small-signal stability and steady-state voltage stability scanning of a simplified model of the Australian national electricity market with significant penetration of renewable generation. The simulation results show the effectiveness of the proposed approach. Compared to an exhaustive time series scanning, the proposed framework reduced the computational burden up to ten times, with an acceptable level of accuracy.
Autors: Ruidong Liu;Gregor Verbič;Jin Ma;David J. Hill;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 514 - 524
Publisher: IEEE
 
» Fast-Response MoS2-Based Humidity Sensor Braced by SiO2 Microsphere Layers
Abstract:
In this letter, a MoS2-based humidity sensor braced by SiO2 microsphere layers with rapid response was developed. The results demonstrated that the humidity sensor can exhibit a subsecond response. A mechanism based on the morphology and structure of the sensing film was proposed to explain the rapid response behavior of humidity sensors. In addition, the effect of film thickness on response time was discussed. This letter demonstrated that the MoS2-based humidity sensor braced by SiO2 microspheres is suitable for the miniature drip infusion rate detection device.
Autors: Ning Li;Xiang-Dong Chen;Xin-Peng Chen;Xing Ding;Xuan Zhao;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2018, volume: 39, issue:1, pages: 115 - 118
Publisher: IEEE
 
» Feasible Device Architectures for Ultrascaled CNTFETs
Abstract:
Feasible device architectures for ultrascaled carbon nanotubes field-effect transistors (CNTFETs) are studied down to 5.9 nm using a multiscale simulation approach covering electronic quantum transport simulations and numerical device simulations. Schottky-like and ohmiclike contacts are considered. The simplified approach employed in the numerical device simulator is critically evaluated and verified by means of comparing the results with electronic quantum simulation results of an identical device. Different performance indicators, such as the switching speed, switching energy, the subthreshold slope, -ratio, among others, are extracted for different device architectures. These values guide the evaluation of the technology for different application scenarios. For high-performance logic applications, the buried gate CNTFET is claimed to be the most suitable structure.
Autors: Anibal Pacheco-Sanchez;Florian Fuchs;Sven Mothes;Andreas Zienert;Jörg Schuster;Sibylle Gemming;Martin Claus;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jan 2018, volume: 17, issue:1, pages: 100 - 107
Publisher: IEEE
 
» Feasible Region of Optimal Power Flow: Characterization and Applications
Abstract:
The feasible region plays a fundamental role in solving optimal power flow (OPF) problems. In this paper, a mathematical characterization of the feasible region is presented. An equivalence is established between the feasible region of an OPF problem and the union of regular stable equilibrium manifolds of a quotient gradient system (QGS) that is derived from the set of equality and inequality constraints of the OPF problem. It is further shown that the QGS is completely stable and that each trajectory converges to an equilibrium manifold, making the QGS trajectories useful in locating feasible OPF solutions. The theoretical results developed in this paper have been numerically verified in several OPF problems. Finally, the notion of a local feasible region is proposed and discussed.
Autors: Hsiao-Dong Chiang;Chu-Yang Jiang;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 236 - 244
Publisher: IEEE
 
» Feature-Driven Active Learning for Hyperspectral Image Classification
Abstract:
Active learning (AL) has obtained a great success in supervised remotely sensed hyperspectral image classification, since it is able to select highly informative training samples. As an intrinsically biased sampling approach, AL generally favors the selection of samples following discriminative distributions, which are located in low-density areas. However, hyperspectral data are often highly class-mixed, i.e., most samples fluctuate in the overlapping regions of distributions of different classes. In this case, the potential of AL to select effective training samples is more limited. As AL strongly depends on the features, a possibility to increase its capabilities is to transfer the data into a highly discriminative feature space, in which the mixture of distributions that different classes of data follow tends to reduce. Based on this observation, in this paper, we introduce the concept of feature-driven AL, namely, the sample selection is going to be conducted in a given optimized feature space whose superiority is measured by an overall error probability. For illustrative purposes, we used Gabor filtering and morphological profiles for instantiation. Our experimental results, obtained on three real hyperspectral data sets, indicate that the proposed approach can significantly improve the potential of AL for hyperspectral image classification.
Autors: Chenying Liu;Lin He;Zhetao Li;Jun Li;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jan 2018, volume: 56, issue:1, pages: 341 - 354
Publisher: IEEE
 
» Feedforward Strategies for Cooperative Adaptive Cruise Control in Heterogeneous Vehicle Strings
Abstract:
String stability is an essential property to ensure that the fluctuations are attenuated along vehicle strings. This paper focuses on the fulfillment of string stability in the practical case of heterogeneous vehicle strings that comprise vehicles with different dynamic properties. Using the idea of predecessor following, acceleration feedforward, predicted acceleration feedforward, and input signal feedforward are considered as different possible feedforward strategies. For all strategies, the parameter ranges of predecessor vehicles that ensure string stability of a given vehicle are characterized, computed, and validated by simulation.
Autors: Ahmed M. H. Al-Jhayyish;Klaus Werner Schmidt;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jan 2018, volume: 19, issue:1, pages: 113 - 122
Publisher: IEEE
 
» Ferroelectric Gate AlGaN/GaN E-Mode HEMTs With High Transport and Sub-Threshold Performance
Abstract:
This letter demonstrated AlGaN/GaN enhancement-mode (E-mode) high-electron-mobility transistors (HEMTs) with 30-nm Pb(Zr,Ti)O3 ferroelectric gate dielectric. The high-quality interface and polarization coupling resulted in the initial pre-poled ferroelectric polarization toward surface. Then, ferroelectric polarization engineering and gate poling were studied, realizing E-mode HEMTs with very high field-effect mobility of 1819 cm2/, ON/OFF current ratio larger than , and the low sub-threshold slope of 90 mV/decade. Owing to the undestroyed 2-D electron gases channel, ferroelectric gate GaN-based E-mode HEMTs with high transport performance are promising candidates for high-speed logic circuit applications.
Autors: Jiejie Zhu;Lixiang Chen;Jie Jiang;Xiaoli Lu;Ling Yang;Bin Hou;Min Liao;Yichun Zhou;Xiaohua Ma;Yue Hao;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2018, volume: 39, issue:1, pages: 79 - 82
Publisher: IEEE
 
» FFAST: An Algorithm for Computing an Exactly $ k$ -Sparse DFT in $O( klog k)$ Time
Abstract:
It is a well-known fact that the Discrete Fourier Transform (DFT) of an arbitrary -length input signal , can be computed from all the time-domain samples in operations via a Fast Fourier Transform (FFT) algorithm. If the spectrum is -sparse (where ), can we do better? We show that asymptotically in and , when is sub-linear in (precisely, ), where ), and the support of the non-zero DFT coefficients is uniformly random, the fast fourier aliasing-based sparse transform (FFAST) algorithm, proposed in this paper, computes, with asymptotically high probability, the non-zero DFT coefficients of from in arithmetic operations. Further, the constants in the big Oh notation for both sample and computational cost are small, e.g., when , which essentially covers a wide range of sub-linear sparsity cases, the sample cost is less than . Although, in this paper we assume that the samples of the signal observed by the FFAST are noise-free, a noise-robust extension of the FFAST is provided in a companion (Part II) paper [1]. Our approach is based on filter-less sub-sampling of the input signal using a set of carefully chosen uniform sub-sampling patterns guided by the Chinese Remainder Theorem (CRT). The idea is to cleverly exploit, rather than avoid, the resulting aliasing artifacts induced by sub-sampling. Specifically, the sub-sampling operation on the time-domain signal is designed to create aliasing patterns of the non-zero coefficients of the spectrum to “look like” parity-check constraints of a good erasure-correcting sparse-graph code. Next, we show that computing the sparse DFT is equivalent to decoding of an appropriate sparse-graph code. The sparse-graph codes further permit a fast peeling-style decoding. Consequently, the resulting DFT computation is
Autors: Sameer Pawar;Kannan Ramchandran;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2018, volume: 64, issue:1, pages: 429 - 450
Publisher: IEEE
 
» Fiber Splicer Convertible–Mini Preform Fabrication System
Abstract:
We downscale a lab-sized preform fabrication system to a benchtop miniature preform, hence a short-length fiber fabrication system. The system, which is a large-diameter fiber splicer convertible, is compact, low cost, fast, and flexible as compared with standard preform fabrication processes. Using the proposed system incorporating with a solution doping technique, we have successfully fabricated several ~ 1-mm-thick, 40 ± 10 mm long thulium-doped silica and germania–silica preforms. The preforms were drawn to diameter, submeter length low NA thulium-doped fibers. Encouraging absorption and emission behaviors were obtained. The technique is promising and suitable for rapid specialty optical fiber prototyping.
Autors: W. J. Lai;L. Zhang;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2018, volume: 30, issue:2, pages: 201 - 204
Publisher: IEEE
 
» Finite Blocklength and Moderate Deviation Analysis of Hypothesis Testing of Correlated Quantum States and Application to Classical-Quantum Channels With Memory
Abstract:
Martingale concentration inequalities constitute a powerful mathematical tool in the analysis of problems in a wide variety of fields ranging from probability and statistics to information theory and machine learning. Here, we apply techniques borrowed from this field to quantum hypothesis testing, which is the problem of discriminating quantum states belonging to two different sequences, and . We obtain achievability bounds on the finite blocklength type II Stein- and Hoeffding errors which, for i.i.d. states, are in general tighter than the corresponding bounds obtained by Audenaert, Mosonyi, and Verstraete. We also derive finite blocklength bounds and moderate deviation results for pairs of sequences of correlated states satisfying a (non-homogeneous) factorization property. Examples of such sequences include Gibbs states of spin chains with translation-invariant finite range interaction, as well as finitely correlated quantum states. We apply our results to find bounds on the capacity of a certain class of classical-quantum channels with memory, which satisfy a so-called channel factorization property—both in the finite blocklength and moderate deviation regimes.
Autors: Cambyse Rouzé;Nilanjana Datta;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2018, volume: 64, issue:1, pages: 593 - 612
Publisher: IEEE
 
» Finite Frequency $H_{infty }$ Deconvolution With Application to Approximated Bandlimited Signal Recovery
Abstract:
This paper investigates a finite frequency deconvolution problem for single-input–single-output discrete-time systems. Motivated by the fact that many practical signals are located in a finite frequency range, this paper is focused on developing a design method for achieving better deconvolution performance over a finite frequency range. First, a finite frequency deconvolution problem is formulated such that the deconvolution specification is characterized by a modified index associated with the corresponding finite frequency range. By an adapted generalized Kalman–Yakubovich–Popov lemma and an auxiliary vector approach, a matrix inequality condition is obtained for parameterizing a required deconvolution filter, based on which a simple iterative algorithm is then constructed for optimizing the filter performance. Multiobjective deconvolution is further discussed in the same framework. Compared with the traditional frequency weighting strategy, the proposed method can directly analyze and synthesize the deconvolution performance within finite frequency ranges, the advantage of which is demonstrated in a bandlimited signal recovery example.
Autors: Huijun Gao;Xianwei Li;Jianbin Qiu;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jan 2018, volume: 63, issue:1, pages: 203 - 210
Publisher: IEEE
 
» Finite-Difference Time-Domain Modeling of Space–Time-Modulated Metasurfaces
Abstract:
A finite-difference time-domain modeling of finite-size zero thickness space–time-modulated Huygens’ metasurfaces based on generalized sheet transition conditions is proposed and numerically demonstrated. A typical all-dielectric Huygens’ unit cell is taken as an example and its material permittivity is modulated in both space and time, to emulate a traveling-type spatio-temporal perturbation on the metasurface. By mapping the permittivity variation onto the parameters of the equivalent Lorentzian electric and magnetic susceptibility densities, and , the problem is formulated into a set of second-order differential equations in time with nonconstant coefficients. The resulting field solutions are then conveniently solved using an explicit finite-difference technique and integrated with a Yee-cell-based propagation region to visualize the scattered fields taking into account the various diffractive effects from the metasurface of finite size. Several examples are shown for both linear and space–time varying metasurfaces which are excited with normally incident plane and Gaussian beams, showing detailed scattering field solutions. While the time-modulated metasurface leads to the generation of new collinearly propagating temporal harmonics, these harmonics are angularly separated in space, when an additional space modulation is introduced in the metasurface.
Autors: Scott A. Stewart;Tom. J. Smy;Shulabh Gupta;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jan 2018, volume: 66, issue:1, pages: 281 - 292
Publisher: IEEE
 
» Finite-Length Analysis of BATS Codes
Abstract:
BATS codes were proposed for communication through networks with packet loss. A BATS code consists of an outer code and an inner code. The outer code is a matrix generation of a fountain code, which works with the inner code that comprises random linear coding at the intermediate network nodes. In this paper, the performance of finite-length BATS codes is analyzed with respect to both belief propagation (BP) decoding and inactivation decoding. Our results enable us to evaluate efficiently the finite-length performance in terms of the number of batches used for decoding ranging from 1 to a given maximum number, and provide new insights on the decoding performance. Specifically, for a fixed number of input symbols and a range of the number of batches used for decoding, we obtain recursive formulae to calculate the stopping time distribution of BP decoding and the inactivation probability in inactivation decoding. We also find that both the failure probability of BP decoding and the expected number of inactivations in inactivation decoding can be expressed in a power-sum form where the number of batches appears only as the exponent. This power-sum expression reveals clearly how the decoding failure probability and the expected number of inactivation decrease with the number of batches. When the number of batches used for decoding follows a Poisson distribution, we further derive recursive formulas with potentially lower computational complexity for both decoding algorithms. For the BP decoder that consumes batches one by one, three formulae are provided to characterize the expected number of consumed batches until all the input symbols are decoded.
Autors: Shenghao Yang;Tsz-Ching Ng;Raymond W. Yeung;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jan 2018, volume: 64, issue:1, pages: 322 - 348
Publisher: IEEE
 
» FinSAL: FinFET-Based Secure Adiabatic Logic for Energy-Efficient and DPA Resistant IoT Devices
Abstract:
With the emergence of Internet of Things (IoT), there is an urgent need to design energy-efficient and secure IoT devices. For example, IoT devices such as radio frequency identification tags and wireless sensor nodes employ AES cryptographic module that are susceptible to differential power analysis (DPA) attacks. With the scaling of technology, leakage power in the cryptographic device increases, which increases their vulnerability to DPA attack. This paper presents a novel FinFET-based secure adiabatic logic (FinSAL), that is energy-efficient and DPA-immune. The proposed adiabatic FinSAL is used to design logic gates such as buffers, XOR, and NAND. Further, the logic gates based on adiabatic FinSAL are used to implement a positive polarity Reed Muller architecture-based S-box circuit. SPICE simulations at 12.5 MHz show that adiabatic FinSAL (20-nm FinFET technology) S-box circuit saves up to 81% of energy per cycle as compared to the conventional S-box circuit implemented using FinFET (20-nm FinFET technology). Further, the security of adiabatic FinSAL S-box circuit has been evaluated by performing the DPA attack through SPICE simulations. We proved that the FinSAL S-box circuit is resistant to a DPA attack through a developed DPA attack flow applicable to SPICE simulations. Further, the impact of FinSAL on hardware security at different technology nodes of FinFETs (7, 10, 14, and 16 nm) are evaluated. From the simulation results, FinSAL gates at 14-nm FinFET offer superior security with optimum power consumption, therefore is the best candidate to design low-power secure IoT devices.
Autors: S. Dinesh Kumar;Himanshu Thapliyal;Azhar Mohammad;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jan 2018, volume: 37, issue:1, pages: 110 - 122
Publisher: IEEE
 
» Flat-Top CWDM (De)Multiplexer Based on MZI With Bent Directional Couplers
Abstract:
A low-crosstalk and flat-top 4-channel coarse wavelength-division multiplexing (de)multiplexer is proposed and demonstrated. The cascaded Mach-Zehnder interferometers are used to provide flat pass-bands. By utilizing the power splitters based on the bent directional couplers, the crosstalk of the Mach-Zehnder interferometers could be ultra-low for all four channels. The measurement results of the fabricated device show that the crosstalk is <−20 dB over a 12-nm wavelength range, the 0.5-, 1-, and 3-dB bandwidths are ~13, ~16, and ~19 nm for all four channels, which agree well with the simulations. Furthermore, the device footprint can be as small as .
Autors: Hongnan Xu;Yaocheng Shi;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jan 2018, volume: 30, issue:2, pages: 169 - 172
Publisher: IEEE
 
» Flexible Organic Light-Emitting Diode Displays Driven by Inkjet-Printed High-Mobility Organic Thin-Film Transistors
Abstract:
A 3.2-in flexible color display, with a resolution of 50 ppi and composed of bottom-emission multiphoton organic light-emitting diodes (OLEDs) and inkjet-printed organic thin-film transistors (OTFTs) with a bottom-gate/bottom-contact structure on a color filter, was developed. The device could successfully display color videos while being bent, and achieved a maximum luminance of 125 cd/m2 with white light emission. The gate dielectrics of the OTFTs used on the backplane were bilayers of cardo polymer and Parylene, and the material used for the organic semiconductors was dithieno [2,3-d;2’,3’-d’]benzo[1,2-b;4,5-b’]dithiophene blended with polystyrene in tetralin solvent, which was coated using inkjet printing to sufficiently fill the banks composed of a fluorine-based polymer. OTFTs with a channel length of 5 were created using the above process, and the structure achieved a high mobility of 1.2 ), making it suitable for flexible color OLED displays. The mobility was about three times as high as that obtained using solution shearing methods.
Autors: Makoto Mizukami;Seung-Il Cho;Kaori Watanabe;Miho Abiko;Yoshiyuki Suzuri;Shizuo Tokito;Junji Kido;
Appeared in: IEEE Electron Device Letters
Publication date: Jan 2018, volume: 39, issue:1, pages: 39 - 42
Publisher: IEEE
 
» Flow Field Imaging With Ultrasonic Guided Waves for Exploring Metallic Melts
Abstract:
Ultrasonic guided waves enable flow measurements under harsh conditions, which are important, for instance, to monitor and optimize industrial solidification processes. The usage of single mode waveguides overcomes the problem of overheating the transducers, but requires a mechanical scanning for imaging. A multimode waveguide can carry the information of an image, but a scrambling of the signals occurs due to multiple reflections at the waveguide’s boundaries. We propose a new approach to overcome the scrambling and enable flow imaging through a short waveguide: the time-reversal virtual array (TRVA) method. The time invariance of the wave equation in a linear medium allows the refocusing on a limited set of calibrated points, which form the virtual array. This virtual array can conceptually be treated as a phased array. In this paper, the TRVA has been characterized theoretically, numerically, and experimentally. For the first time, a planar velocity measurement of a rotating flow in liquid gallium–indium–tin is demonstrated through a borosilicate waveguide at room temperature. A comparison with reference measurements showed good agreement.
Autors: Mantvydas Kalibatas;Richard Nauber;Christian Kupsch;Jürgen Czarske;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Jan 2018, volume: 65, issue:1, pages: 112 - 119
Publisher: IEEE
 
» Fluid Dynamic Models for Bhattacharyya-Based Discriminant Analysis
Abstract:
Classical discriminant analysis attempts to discover a low-dimensional subspace where class label information is maximally preserved under projection. Canonical methods for estimating the subspace optimize an information-theoretic criterion that measures the separation between the class-conditional distributions. Unfortunately, direct optimization of the information-theoretic criteria is generally non-convex and intractable in high-dimensional spaces. In this work, we propose a novel, tractable algorithm for discriminant analysis that considers the class-conditional densities as interacting fluids in the high-dimensional embedding space. We use the Bhattacharyya criterion as a potential function that generates forces between the interacting fluids, and derive a computationally tractable method for finding the low-dimensional subspace that optimally constrains the resulting fluid flow. We show that this model properly reduces to the optimal solution for homoscedastic data as well as for heteroscedastic Gaussian distributions with equal means. We also extend this model to discover optimal filters for discriminating Gaussian processes and provide experimental results and comparisons on a number of datasets.
Autors: Yung-Kyun Noh;Jihun Hamm;Frank Chongwoo Park;Byoung-Tak Zhang;Daniel D. Lee;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Jan 2018, volume: 40, issue:1, pages: 92 - 105
Publisher: IEEE
 
» Flux–Charge Memristor Model for Phase Change Memory
Abstract:
Phase-change memory (PCM) is one of the most promising non-volatile memory technologies and is finding applications in areas such as storage-class memory and emerging non-von Neumann computing systems. Even though powerful physics-based models have been developed for these devices, there is a lack of simple and accurate circuit models to describe these elements. In this brief, we exploit memristor theory to obtain a simple and reliable circuit model based on electrical variables such as charge and flux. This model is based on experimental measurements of PCM devices fabricated in the 90 nm technology node.
Autors: Jacopo Secco;Fernando Corinto;Abu Sebastian;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2018, volume: 65, issue:1, pages: 111 - 114
Publisher: IEEE
 
» FMCW SAR System for Near-Distance Imaging Applications—Practical Considerations and Calibrations
Abstract:
A combination of frequency-modulated continuous-wave (FMCW) technology with a synthetic aperture radar (SAR) technique is a highly sought after method, which leads to a compact and cost-effective imaging system, for near-distance target imaging. One of the limiting factors of FMCW radars is that the ramp signal modulates the received signal, which limits the minimum achievable range resolution. In addition, the voltage-controlled oscillator (VCO) adds a certain degree of phase noise and nonlinearity to the transmitted signal that degrades the signal-to-noise ratio, range accuracy, and image resolution. This paper presents a signal processing procedure with system calibration methods to mitigate the effect of deramp, phase noise, and nonlinearity of the VCO on the beat spectrum. Additionally, the effect of phase noise of the received signal on the SAR image resolution in both range and cross-range directions is comprehensively studied. To improve the range accuracy, different calibration methods are proposed. An -band homodyne FMCW radar system, using off-the-shelf components, is designed for near-distance target imaging using linear and circular SAR techniques. The reconstructed images show the improvement of image quality and accuracy in target position.
Autors: Jui-Wen Ting;Daniel Oloumi;Karumudi Rambabu;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jan 2018, volume: 66, issue:1, pages: 450 - 461
Publisher: IEEE
 
» Focus and Blurriness Measure Using Reorganized DCT Coefficients for an Autofocus Application
Abstract:
In this paper, two metrics for measuring image sharpness are presented and used for an autofocus (AF) application. Both measures exploit reorganized discrete cosine transform (DCT) representation. The first metric is a focus measure, which involves optimal high- and middle-frequency coefficients to evaluate relative sharpness. It is robust to noise while remaining sensitive to the best focus position. A psychometric function-based metric is introduced to quantify the focus measure. The second metric is a no-reference blurriness metric, which is used to measure absolute blurriness. It first constructs multiscale DCT edge maps using directional energy information and then determines image blurriness by combining change information in edge structures with image contrast. This metric gives predictions that are closely correlated with subjective perceived scores and shows performance comparable with that of state-of-the-art methods, especially for noisy images. For noisy situations, the two metrics are adjusted adaptively according to the estimated noise level. To prevent the introduction of extra computational load, an efficient noise-level estimation algorithm based on median absolute deviation is presented. This algorithm exploits only the available reorganized DCT coefficients. With the focus and blurriness measures, an AF method for which the two metrics play an important role was developed. Because of their high-quality performance, the realized AF function is able to locate the best focus position swiftly and reliably.
Autors: Zheng Zhang;Yu Liu;Zhihui Xiong;Jing Li;Maojun Zhang;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jan 2018, volume: 28, issue:1, pages: 15 - 30
Publisher: IEEE
 
» Forced Decryption and the Fifth Amendment: A Technical Perspective
Abstract:
It is not sufficient to do justice by obtaining a proper result by irregular or improper means. Chief Justice Earl Warren Miranda v. Arizona, 384 U.S. 436 (1966)
Autors: Stephen B. Wicker;
Appeared in: Proceedings of the IEEE
Publication date: Jan 2018, volume: 106, issue:1, pages: 3 - 6
Publisher: IEEE
 
» Forecast-Based Anticipatory Frequency Control in Power Systems
Abstract:
The imbalance of load and generation can be significant when large amounts of renewable generation are being integrated in power systems. If not dealt effectively, this uncertainty can result in excessive deviations of frequency and tie-line flows. A model predictive control method, termed anticipatory frequency control, is used with predicted disturbances (e.g., from solar or wind generation) within the conventional automatic generation control (AGC) framework to minimize system frequency and tie-line deviations. The controller is shown to reduce the frequency and tie-line deviations over time in a multiarea test power system when compared with conventional control methods. In addition, the impact of imperfect forecasts and controller objective function weighting on the performance of anticipatory control is carefully examined.
Autors: David Ganger;Junshan Zhang;Vijay Vittal;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 1004 - 1012
Publisher: IEEE
 
» Forecasting Functional Time Series with a New Hilbertian ARMAX Model: Application to Electricity Price Forecasting
Abstract:
A functional time series is the realization of a stochastic process where each observation is a continuous function defined on a finite interval. These processes are commonly found in electricity markets and are gaining more importance as more market data become available and markets head toward continuous-time marginal pricing approaches. Forecasting these time series requires models that operate with continuous functions. This paper proposes a new functional forecasting method that attempts to generalize the standard seasonal ARMAX time series model to the Hilbert space. The structure of the proposed model is a linear regression where functional parameters operate on functional variables. The variables can be lagged values of the series (autoregressive terms), past observed innovations (moving average terms), or exogenous variables. In this approach, the functional parameters used are integral operators whose kernels are modeled as linear combinations of sigmoid functions. The parameters of each sigmoid are optimized using a Quasi-Newton algorithm that minimizes the sum of squared errors. This novel approach allows us to estimate the moving average terms in functional time series models. The new model is tested by forecasting the daily price profile of the Spanish and German electricity markets and it is compared to other functional reference models.
Autors: José Portela González;Antonio Muñoz San Roque;Estrella Alonso Pérez;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 545 - 556
Publisher: IEEE
 
» FPGA-Based Hardware Implementation of Real-Time Optical Flow Calculation
Abstract:
Optical flow calculation algorithms are hard to implement on the hardware level in real-time, due to their complexity and high computational load. Therefore, presented works in the literature focusing on the hardware implementation are limited. In this paper, we present a hierarchical block matching-based optical flow algorithm suitable for real-time hardware implementation. The algorithm estimates the initial optical flow with block matching and refines the vectors with local smoothness constraints in each level. We evaluate the proposed algorithm with novel data sets and provide results compared with the ground truth optical flow. Furthermore, we present a reconfigurable hardware architecture of the proposed algorithm for calculating the optical flow in real-time. The presented system can process resolution frames at 39 frames/s.
Autors: Kerem Seyid;Andrea Richaud;Raffaele Capoccia;Yusuf Leblebici;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Jan 2018, volume: 28, issue:1, pages: 206 - 216
Publisher: IEEE
 
» Fractal Characteristics Analysis of Blackouts in Interconnected Power Grid
Abstract:
The power failure models are a key to understand the mechanism of large scale blackouts. In this letter, the similarity of blackouts in interconnected power grids (IPGs) and their subgrids is discovered by the fractal characteristics analysis to simplify the failure models of the IPG. The distribution characteristics of blackouts in various subgrids are demonstrated based on the Kolmogorov–Smirnov (KS) test. The fractal dimensions (FDs) of the IPG and its subgrids are then obtained by using the KS test and the maximum likelihood estimation. The blackouts data in China were used to demonstrate the similarity of distribution characteristics and FDs of the IPG and its subgrids. The results are consistent with the development of the power grids.
Autors: Feng Wang;Lijuan Li;Canbing Li;Qiuwei Wu;Yijia Cao;Bin Zhou;Baling Fang;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jan 2018, volume: 33, issue:1, pages: 1085 - 1086
Publisher: IEEE
 
» Free-Surface Time-Series Generation for Wave Energy Applications
Abstract:
Finite-length, numerical simulations of Gaussian seas are widely used in the wave energy sector. The most common method consists of adding up harmonic sinusoidal components, with random phases and deterministic amplitudes derived from the target wave spectrum [deterministic amplitude scheme (DAS)]. In another approach, the component amplitudes are chosen randomly with a variance depending on the spectrum [random amplitude scheme (RAS)]. It is now generally accepted that only the latter method reproduces the true statistical properties of a Gaussian sea. Compared to previous works, this study clarifies the exact nature of the “statistical properties” that should be represented in the simulation process. Further analysis is carried out to address unanswered questions highlighted in the existing literature, especially with respect to the statistical relationships between discrete successive simulation points, and the probability law governing the average power estimator of a wave energy converter (WEC) simulated with the generated wave time series. It is shown that RAS exactly reflects how the WEC performance, considered over a finite duration, varies with respect to its long-term average, whereas DAS has the advantage of providing accurate estimates of the long-term average values using fewer, or shorter, simulations; in particular, it is demonstrated that only one simulation is sufficient when the WEC model is linear. Furthermore, it is shown why alternative methods, based on nonharmonic superposition of sinusoids, are not recommended. The effects of the simulation method (RAS or DAS) upon the statistics of individual oscillations in the time domain are also explored experimentally. Finally, a table is provided that gives recommendations, depending on the objective of the simulations.
Autors: Alexis Mérigaud;John V. Ringwood;
Appeared in: IEEE Journal of Oceanic Engineering
Publication date: Jan 2018, volume: 43, issue:1, pages: 19 - 35
Publisher: IEEE
 
» Frequency Limited Model Reduction Techniques With Error Bounds
Abstract:
The main issue with the pioneer frequency limited interval Gramian-based technique by Gawronski and Jaung is that it yields unstable reduced order models. There exist some techniques in literature that yield stable reduced order models, however, these techniques yield relatively more frequency response errors. In this brief, three frequency limited interval Gramians-based model order reduction techniques are proposed. The proposed techniques ensure the stability of the reduced order models, produce relatively lower frequency response error (as compared with existing stability preserving techniques) and yield the frequency response error bounds. Numerical examples along with comparison among different techniques are presented which show the effectiveness (relatively low approximation error as compared with other existing stability preserving model order reduction techniques) of the proposed techniques.
Autors: Muhammad Imran;Abdul Ghafoor;Muhammad Imran;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jan 2018, volume: 65, issue:1, pages: 86 - 90
Publisher: IEEE
 

Publication archives by date

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

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

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

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

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

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

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

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

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

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

 
0-C     D-L     M-R     S-Z