Electrical and Electronics Engineering publications abstract of: 05-2017 sorted by title, page: 10

» Initiator-Integrated 3-D Printing of Magnetic Object for Remote Controlling Application
Abstract:
Magnetically driven micromachines play an essential role in a number of biomedical and other remote control applications. In this paper, a magnetically driven robot composed of customized UV-curable resin was fabricated by (3-D) printing via initiator-triggered radical polymerization and the subsequent polyelectrolyte-brush-assisted electroless plating. A layer of magnetic material was grown in situ on the 3-D printed structure, which exhibited soft-magnetic properties proved by the vibrating sample magnetometer measurement. The magnetic robot was successfully actuated under the rotating magnetic field produced from a manipulator of permanent magnet. By utilizing the spiral structure, the 3-D robot was designed to translate rotational movement into linear motion. A comprehensive investigation was also carried out on the optimization of spiral shape, liquid viscosity and the strategy of magnetic controlling. The remote controlling experiments demonstrate that this initiator-integrated 3-D printing is an effective technique for making magnetically driven objects.
Autors: Dongxing Zhang;Junfeng Xiao;Yejun Qiu;Jun Yang;Qiuquan Guo;
Appeared in: IEEE Transactions on Magnetics
Publication date: May 2017, volume: 53, issue:5, pages: 1 - 9
Publisher: IEEE
 
» Innovative Mobile Robot Method: Improving the Learning of Programming Languages in Engineering Degrees
Abstract:
This paper describes a study of teaching a programming language in a C programming course by having students assemble and program a low-cost mobile robot. Writing their own programs to define the robot’s behavior raised students’ motivation. Working in small groups, students programmed the robots by using the control structures of structured programming. Over the course, there was a significant improvement in students’ academic performance and motivation. The approach took into account four of the motivational factors that feature in the ARCS model: 1) attention; 2) relevance; 3) confidence; and 4) satisfaction. The main achievements of the approach were to be able to: 1) catch and hold students’ attention throughout the course; 2) increase students’ confidence in the learning process; 3) achieve a high student satisfaction level with their acquired skills; and 4) demonstrate to students the practical usefulness of the knowledge they had learned. This paper also determines the extent to which this strategy was effective in meeting the teaching goals.
Autors: Octavio Ortiz Ortiz;Juan Ángel Pastor Franco;Pedro María Alcover Garau;Ruth Herrero Martín;
Appeared in: IEEE Transactions on Education
Publication date: May 2017, volume: 60, issue:2, pages: 143 - 148
Publisher: IEEE
 
» Insights Into Interface Treatments in p-Channel Organic Thin-Film Transistors Based on a Novel Molecular Semiconductor
Abstract:
Organic thin-film transistors (OTFTs) were fabricated using a novel small molecule, C6-NTTN, as the semiconductor layer in several different architectures. The C6-NTTN layer was deposited via both vacuum evaporation at different substrate temperatures and via solution-processing, which yield maximum hole mobilities of 0.16 and 0.05 cm2/, respectively. Surface treatments of the substrate, insulator, and metal contacts used for OTFT fabrication employing polymer films and different self-assembled monolayers were investigated. In particular, in bottom-gate devices, the insulator surface hydrophobicity was optimized by the deposition of poly(methyl methacrylate) or hexamethyldisilazane, while in the top-gate geometry, pentafluorobenzenethiol was efficiently used to modify the substrate surface energy and to change the contact work function. Atomic force microscopy analysis was exploited to understand the relationship between the semiconductor thin-film morphology and the device electrical performance. The results shown here indicate an inverse proportionality between the mobility and the interface trap density, with parameters depending especially on semiconductor–insulator interfacial properties, and a correlation between the threshold voltage and the characteristics of the semiconductor–metal interface.
Autors: Rosalba Liguori;Hakan Usta;Sandra Fusco;Antonio Facchetti;Gian Domenico Licciardo;Luigi Di Benedetto;Alfredo Rubino;
Appeared in: IEEE Transactions on Electron Devices
Publication date: May 2017, volume: 64, issue:5, pages: 2338 - 2344
Publisher: IEEE
 
» Inspection of Cracks in Aluminum Multilayer Structures Using Planar ECT Probe and Inversion Problem
Abstract:
This paper proposes a method to detect and evaluate surface and subsurface cracks in aluminum multilayer structures using a planar eddy current testing (ECT) probe and processing an inverse problem algorithm. The proposed excitation method using this ECT probe allows the induction of eddy currents with different orientations on the metal surface without rotating the probe during the scan. An inversion algorithm was applied to evaluate the geometry of the cracks. The main result of this inversion algorithm is the determination of the shape of the cracks using the reconstructed eddy current pattern inside the specimen. These reconstructed patterns give the indication of the length, orientation, and geometry profile of the crack. In this paper, complex geometry cracks at different depths are inspected. Experimental data were obtained around a star crack at different depths in a stack of four aluminum plates where each plate has a thickness equal to 1 mm. The presented work shows that the distance between the sensor and the layer under analysis must be adjusted in the inversion process in order to obtain the best reconstructed images when subsurface cracks are under study. This consideration affects the quality of the resulting images.
Autors: Dario Jerónimo Pasadas;Artur Lopes Ribeiro;Helena Geirinhas Ramos;Tiago Jorge Rocha;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: May 2017, volume: 66, issue:5, pages: 920 - 927
Publisher: IEEE
 
» Instantaneous Feedback Control for a Fuel-Prioritized Vehicle Cruising System on Highways With a Varying Slope
Abstract:
This paper presents two fuel-prioritized feedback controllers, which are called the estimated minimum principle (EMP) and kinetic energy conversion (KEC), to realize eco-cruising on varying slopes for vehicles with conventional powertrains. The former is derived from the minimum principle with an estimated Hamiltonian, and the latter is designed based on the equivalent conversion between the kinetic-energy change of vehicle body and the fuel consumption of the engine. They are implemented with analytical control laws and rely on current road slope information only without look-ahead prediction. This feature results in a very light computing load, with the average computing time of each step less than one millisecond. Their fuel-saving performances are quantitatively studied and compared with a model predictive control and a constant speed control. As an expansion, the control rule for avoiding rear-end collision is also designed by using a safety-guaranteed car-following model to constrain the high-risk behaviors.
Autors: Shaobing Xu;Shengbo Eben Li;Bo Cheng;Keqiang Li;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: May 2017, volume: 18, issue:5, pages: 1210 - 1220
Publisher: IEEE
 
» Instantaneous Power Quality Indices Based on Single-Sideband Modulation and Wavelet Packet-Hilbert Transform
Abstract:
Diverse conditions in power systems, such as massive use of nonlinear loads, continuous switching and operation of large electrical loads, and the integration of renewable energies, among others, have adversely affected the power quality (PQ) because they produce undesirable distortions in the waveforms of voltage and current. The conventional way to quantify the PQ is using the PQ indices (PQIs). Yet, the nonstationary properties of voltage and current signals degrade the PQIs estimation whenever classical techniques are used. In this paper, a methodology based on single-sideband modulation method and the Wavelet and Hilbert transforms for the estimation of instantaneous PQIs is proposed. It is shown that the proposal yields better tracking of transitory changes in the voltage/current signals than classical techniques such as the short-time Fourier transform. The PQIs used are the root-mean-square values, frequency, total harmonic distortion, active power, reactive power, apparent power, distortion power, power factor, and total power factor. PQIs performance is validated using synthetic and real signals.
Autors: Ismael Urbina-Salas;Jose R. Razo-Hernandez;David Granados-Lieberman;Martin Valtierra-Rodriguez;Jose E. Torres-Fernandez;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: May 2017, volume: 66, issue:5, pages: 1021 - 1031
Publisher: IEEE
 
» Insulated Bus Bars in Low-Voltage Systems: Reducing Arc Duration and Energy Emissions
Abstract:
Power distribution equipment is the backbone of any industrial process infrastructure. Safety and reliability are the two most important criteria in the proper functioning of the power distribution system. Low-voltage switchgear (LVS) is an important part of power distribution. Minimizing arc faults in the switchgear is a matter of utmost concern to maintain a safe environment. Arc-resistant LVS is designed to provide an additional degree of protection for operating personnel performing normal duties near the equipment. In this article, we report a series of arc-flash simulations performed on an arc-resistant LVS in both bare bus (noninsulated) and insulated or isolated bus configurations. In all simulations, the insulated or isolated bus had a significantly shorter arc duration and lower energy emissions.
Autors: Rahul Rajvanshi;Tom Hawkins;
Appeared in: IEEE Industry Applications Magazine
Publication date: May 2017, volume: 23, issue:3, pages: 48 - 53
Publisher: IEEE
 
» Integrated Safety Management: Creating an All-Inclusive Electrical Safety Program
Abstract:
Electrical safety is imperative for kee ping workers safe, and a safety management system is a means to implement it. The safety management system known as Integrated Safety Management (ISM) is a formal and proven system for the safe execution of work activities. The ISM system can be incorporated into a work-control process and structure an electrical safety program through its guiding principles and core functions. An electrical safety work-control process has two components that need to be implemented for success: a National Fire Protection Association (NFPA) 70E-based electrical safety program and an ISM-based work-control process. An electrical safety program that implements the seven guiding principles and five core functions listed in Table 1 gives a well-defined and document-supported process to keep workers safe.
Autors: Robert Joseph Spang;
Appeared in: IEEE Industry Applications Magazine
Publication date: May 2017, volume: 23, issue:3, pages: 64 - 70
Publisher: IEEE
 
» Integrated Virtual Impactor Enabled PM2.5 Sensor
Abstract:
As more and more proofs show that fine particles (diameter of and below) pose more risk on human health than coarse particles, an increasing need for monitoring fine particles has emerged. A miniaturized sensor designed for measuring fine particle concentration is presented in this paper. The proposed sensor possesses a compact size of only 15 mm mm mm. A virtual impactor has been integrated as a particle size selector and the design is optimized by simulation-assisted analysis. The sensor is realized by silicon microfabrication and wafer-level packaging. Testing results show that a high measurement accuracy of has been achieved.
Autors: Mingzhi Dong;Elina Iervolino;Fabio Santagata;Guoyi Zhang;Guoqi Zhang;
Appeared in: IEEE Sensors Journal
Publication date: May 2017, volume: 17, issue:9, pages: 2814 - 2821
Publisher: IEEE
 
» Integrating Collaborative and Live Coding for Distance Education
Abstract:
What does an online programming course need to engage students and improve their skills? To answer this question, the authors designed and tested a feature-rich collaborative environment for an online class and found that it enhanced learning through methods such as remote pair programming, live coding, and a tight code-to-artifact feedback loop.
Autors: Soroush Ghorashi;Carlos Jensen;
Appeared in: Computer
Publication date: May 2017, volume: 50, issue:5, pages: 27 - 35
Publisher: IEEE
 
» Integration of Ant Colony Optimization and Object-Based Analysis for LiDAR Data Classification
Abstract:
Light detection and ranging (LiDAR) data classification provides useful thematic maps for numerous geospatial applications. Several methods and algorithms have been proposed recently for LiDAR data classification. Most studies focused on object-based analysis because of its advantages over per-pixel-based methods. However, several issues, such as parameter optimization, attribute selection, and development of transferable rulesets, remain challenging in this topic. This study contributes to LiDAR data classification by developing an approach that integrates ant colony optimization (ACO) and rule-based classification. First, LiDAR-derived digital elevation and digital surface models were integrated with high-resolution orthophotos. Second, the processed raster was segmented with the multiresolution segmentation method. Subsequently, the parameters were optimized with a supervised technique based on fuzzy analysis. A total of 20 attributes were selected based on general knowledge on the study area and LiDAR data; the best subset containing 12 attributes was then selected via ACO. These attributes were utilized to develop rulesets through the use of a decision tree algorithm, and a thematic map was generated for the study area. Results revealed the robustness of the proposed method, which has an overall accuracy of ∼95% and a kappa coefficient of 0.94. The rule-based approach with all attributes and the k nearest neighbor (KNN) classification method were applied to validate the results of the proposed method. The overall accuracy of the rule-based method with all attributes was ∼88% (kappa = 0.82), whereas the KNN method had an overall accuracy of <70% and produced a poor thematic map. The selection of the ACO algorithm was justified through a comparison with three well-known feature selection methods. On the oth- r hand, the transferability of the developed rules was evaluated by using a second LiDAR dataset at another study area. The overall accuracy and the kappa index for the second study area were 92% and 0.90, respectively. Overall, the findings indicate that the selection of a subset with significant attributes is important for accurate LiDAR data classification with object-based methods.
Autors: Maher Ibrahim Sameen;Biswajeet Pradhan;Helmi Z. M. Shafri;Mustafa Ridha Mezaal;Hussain bin Hamid;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: May 2017, volume: 10, issue:5, pages: 2055 - 2066
Publisher: IEEE
 
» Intelligent Charge Rate Optimization of PHEVs Incorporating Driver Satisfaction and Grid Constraints
Abstract:
In this paper, an optimization model is developed to find a plug-in hybrid electric vehicle (PHEV) optimum charging rate profile that dynamically varies throughout the day. From the grid point of view, the model takes into account the constraints of maximum demand and charging facilities, while from the driver’s point of view, waiting and charging time restrictions are considered. The novelty of this paper lies in maximizing the energy delivered to PHEVs in a region equipped with smart grid technology by intelligently alternating charging rates during the day while incorporating both driver satisfaction constraints as well as grid limitations. Using the proposed optimization model, two cases with optimized charging rates are studied and compared with constant charging levels. Furthermore, quantitative results from the perspective of both power grid contribution and driver satisfaction are presented and discussed in detail for each case.
Autors: Zahra Darabi;Poria Fajri;Mehdi Ferdowsi;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: May 2017, volume: 18, issue:5, pages: 1325 - 1332
Publisher: IEEE
 
» Interactive Evolution Strategies for Minimizing Single-objective Functions
Abstract:
This article discusses issues related to the application of the user interactivity in optimization process, aided by the method of the Evolution Strategies, with the objective of improve the minimization process of the evaluated functions, both in their response and in the time of obtaining, through the intervention of the user. Its development is based on the methodology of the Evolution Strategies, characterized by the concept of natural selection. However, the minimization process requires an intervention in the stagnations of local minima to get a better efficiency. To increase the applicability of the approached methodology, it is proposed the use of the user interactivity in minimization process, allowing the manipulation of mutation rate and recombination, activation of the mutation of self-adaptive parameters as well as monitoring the whole process. The proposed methodology was used in the evaluation of test functions for optimization, as well as in the evaluation of a real case.
Autors: Luiz Henrique Reis Jesus;Leonardo Cunha Brito;
Appeared in: IEEE Latin America Transactions
Publication date: May 2017, volume: 15, issue:5, pages: 981 - 987
Publisher: IEEE
 
» Interactive Model for Energy Management of Clustered Microgrids
Abstract:
The increasing integration of distributed renewable energy resources highlights the need to design new control strategies for hybrid wind turbine-photovoltaic (WT-PV)-battery microgrid (MG) clusters. This paper proposes a two-level optimization model for the coordinated energy management between distribution systems and clustered WT-PV-battery MGs. The upper level of the model deals with the operation of the distribution network, while the lower level considers the coordinated operation of multiple MGs. An interactive game matrix (IGM) is applied to coordinate the power exchange among multiple MGs, and between the distribution network and MGs. The model is solved by a modified hierarchical genetic algorithm. Case studies on a distribution system with MGs, as well as a practical multi-MG system, demonstrate the effectiveness of the proposed method in improving power quality, reliability, and environmental benefits.
Autors: Tianguang Lu;Zhaoyu Wang;Qian Ai;Wei-Jen Lee;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 1739 - 1750
Publisher: IEEE
 
» Interactive Research-Based Instruction Strategies for Standards Education: Project ISTEE
Abstract:
Efforts are underway to advance technical standards education into science, technology, engineering, and mathematics (STEM) university programs. This article provides an overview of Project ISTEE: Integrating Standards into Telecommunication Engineering Education. We discuss the background and motivations behind this project and describe its tasks and deliverables. The project produces a university course in telecommunication standards and standardization processes. Evaluation results of two offerings of this course are reported and discussed. Our findings confirm that interactive research-based instruction strategies are particularly suitable for standards education. A model for standards education is developed that can be adopted by other STEM disciplines.
Autors: Tarek S. El-Bawab;Frank Effenberger;
Appeared in: IEEE Communications Magazine
Publication date: May 2017, volume: 55, issue:5, pages: 110 - 114
Publisher: IEEE
 
» Interactive Satellite Image Change Detection With Context-Aware Canonical Correlation Analysis
Abstract:
Automatic change detection is one of the remote sensing applications that has received an increasing attention during the last years. However, fully automatic solutions reach their limitation; on the one hand, it is difficult to design general decision criteria able to select area of changes for images under various acquisition conditions, and on the other hand, the relevance of changes may differ from one user to another. In this letter, we introduce an alternative change detection method based on relevance feedback. The proposed algorithm is iterative and based on a query and answer model that: 1) asks the user questions about the relevance of his targeted changes and 2) according to these answers, updates change detection results. Our method is also based on a new formulation of canonical correlation analysis (CCA), referred to as context-aware CCA, that learns transformations, which map data from different input spaces (related to multitemporal satellite images) into a common latent space, which is sensitive to relevant changes while being resilient to irrelevant ones. These CCA transformations correspond to the optimum of a particular constrained maximization problem that mixes an alignment term with a context-based regularization criterion. The particularity of this novel CCA approach resides in its ability to exploit spatial geometric context resulting into better performances compared with other CCA approaches, as shown in experiments.
Autors: Hichem Sahbi;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 607 - 611
Publisher: IEEE
 
» Intercloud and HetNet for Mobile Cloud Computing in 5G Systems: Design Issues, Challenges, and Optimization
Abstract:
Emerging 5G systems will feature a closer collaboration between mobile network operators and cloud service providers to meet the communication and computational requirements of modern mobile applications and services in a mobile cloud computing (MCC) environment. In this article, we show how the marriage between heterogeneous wireless networks (HetNets) and multiple clouds (a collection of which is referred to here as Intercloud) stands out as an effective response for the mobile data deluge. First, we review the building blocks of a HetNet and an Intercloud as well as the resource management entities in both domains. Second, we outline how they might be orchestrated to better support the task offloading process. Third, we identify the key design criteria and challenges related to interoperation between an Intercloud and a HetNet. We then formulate a revenue sharing approach for a coalition between a mobile network operator and cloud service providers. The approach achieves the maximum revenue for the coalition by optimally associating the users to the clouds through the base stations. Next, the concept of Shapley value is applied to individualize the contribution of each player based on the maximum revenue for the optimal user association. Numerical results illustrate the benefits of the coalition for all players.
Autors: Glaucio H.S. Carvalho;Isaac Woungang;Alagan Anpalagan;Muhammad Jaseemuddin;Ekram Hossain;
Appeared in: IEEE Network
Publication date: May 2017, volume: 31, issue:3, pages: 80 - 89
Publisher: IEEE
 
» Interdisciplinary Education for Design Innovation
Abstract:
A design education program must unite traditionally siloed disciplines, spanning rigid academic boundaries from engineering to social sciences. Work to establish the Kyoto University Design School had to meet these challenges in promoting interdisciplinary cooperation and provides a solid model for others to build on. The web extra at https://youtu.be/bTWoIew-lpg features interviews and further details about Kyoto University Design School's innovative curriculum.
Autors: Toru Ishida;Tetsuo Sawaragi;Kumiyo Nakakoji;Takushi Sogo;
Appeared in: Computer
Publication date: May 2017, volume: 50, issue:5, pages: 44 - 52
Publisher: IEEE
 
» Interferometry With ALOS-2 Full-Aperture ScanSAR Data
Abstract:
Advanced Land Observing Satellite-2 (ALOS-2) is designed to routinely acquire both scanning synthetic aperture radar (ScanSAR) and stripmap data. In this paper, we present a special multiband bandpass filter (MBF) to remove azimuth nonoverlap spectra for the interferometric processing of ALOS-2 full-aperture ScanSAR product. As required by the MBF, we estimate the important ScanSAR system parameters and the start times of raw bursts using ALOS-2 full-aperture ScanSAR image. The resulting MBF can remove the nonoverlap spectra caused by both Doppler centroid frequency difference and burst misalignment. It can be used in ScanSAR-ScanSAR interferometry, as well as ScanSAR-stripmap interferometry. Based on the MBF, we propose a single processing workflow that is able to implement both ScanSAR-ScanSAR interferometry and ScanSAR-stripmap interferometry. Finally, we present example interferograms of the 2015 Gorkha earthquake in Nepal processed using the proposed processing workflow. The interferograms are greatly improved after applying the MBF to remove the significant amount of nonoverlap spectra in the data.
Autors: Cunren Liang;Eric J. Fielding;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: May 2017, volume: 55, issue:5, pages: 2739 - 2750
Publisher: IEEE
 
» Interlocking Patent Rights and Value Appropriation: Insights From the Razor Industry
Abstract:
This paper analyzes a duopoly-like situation in the wet shaving industry featuring an innovation leader and a follower. In this, the leader claims to have filed “interlocking” patents. The explorative case study examines how the leader filed said patents and how their structures have affected potential value appropriation. In fact, the market leader has claimed technical elements in multiple patents, while the patents themselves do not legally overlap. This analysis will also cover triggers and boundary conditions that facilitate or limit such claim compositions. Finally, the market leader has seemingly been able to successfully appropriate value from its strategy. This study will contribute to the literature on value appropriation, the interplay between corporate engineering and intellectual property functions, as well as the economics literature on patent thickets.
Autors: Christian Sternitzke;
Appeared in: IEEE Transactions on Engineering Management
Publication date: May 2017, volume: 64, issue:2, pages: 249 - 265
Publisher: IEEE
 
» Internet Computing Begins
Abstract:
In celebration of IEEE Internet Computing's 20th anniversary, the inaugural Editor-in-Chief Charles Petrie reminisces about the time period surrounding the magazine's beginnings, as well as how IC became the IEEE Computer Society's first magazine posted online.
Autors: Charles Petrie;
Appeared in: IEEE Internet Computing
Publication date: May 2017, volume: 21, issue:3, pages: 6 - 7
Publisher: IEEE
 
» Internet Evolution
Abstract:
Can the Internet evolve, and what is the direction of this evolution? This article offers a plausible model for Internet evolution, and explains its implications for different stakeholders.
Autors: Dah Ming Chiu;
Appeared in: IEEE Internet Computing
Publication date: May 2017, volume: 21, issue:3, pages: 78 - 81
Publisher: IEEE
 
» Internet of Education Resources Using a Chemistry-Inspired Framework
Abstract:
Open education resources (OERs) are public domain learning objects used extensively in both online and traditional education settings. To facilitate the use of OERs, a novel chemistry-inspired framework links learning objects to help the education community contribute, augment, and locate these valuable resources.
Autors: Henry C.B. Chan;
Appeared in: Computer
Publication date: May 2017, volume: 50, issue:5, pages: 54 - 60
Publisher: IEEE
 
» Interpolation of Ewald-Accelerated Periodic Green’s Function Representations for Homogeneous or Layered Media
Abstract:
A method is explored and developed for significantly accelerating the computation of the Ewald series representation for periodic homogeneous media Green’s functions. The method involves extracting corner singularity terms from the corners of the unit cell, resulting in a smooth regularized Green’s function that is amenable to interpolation. The approach can be used to accelerate layered-media problems, where application of Kummer’s method splits the spectral (Floquet modal) series representation into a rapidly converging difference series that is regular plus a residual series that contains any spatial singularities present. The residual series corresponds to a homogeneous medium, and can thus be treated with the method proposed here.
Autors: Ferhat Turker Celepcikay;Donald R. Wilton;David R. Jackson;William A. Johnson;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: May 2017, volume: 65, issue:5, pages: 2517 - 2525
Publisher: IEEE
 
» Intrinsic Interference Based Physical Layer Encryption for OFDM/OQAM
Abstract:
A physical layer encryption method is proposed for orthogonal frequency division multiplexing with offset quadrature amplitude modulation. The proposed method uses intentionally added pure imaginary symbols as keys, so that their intrinsic interferences can obfuscate true data symbols at the eavesdroppers. The key generation method and four loading patterns are proposed. Also, the impact of channel estimation error, the robustness against ciphertext attacks, and the information leakage at the eavesdropper are analyzed. Finally, the performance of the proposed method is evaluated through numerical simulations.
Autors: Manabu Sakai;Hai Lin;Katsumi Yamashita;
Appeared in: IEEE Communications Letters
Publication date: May 2017, volume: 21, issue:5, pages: 1059 - 1062
Publisher: IEEE
 
» Introduction to the Special Section on the 2016 Radio Frequency Integrated Circuits (RFIC) Symposium
Abstract:
This issue of the IEEE Journal of Solid-State Circuits includes a selection of papers presented at last year’s Radio-Frequency Integrated Circuits (RFIC) Symposium, highlighting some of the main advances in radio-frequency integrated circuit design. The RFIC Symposium, which is part of the IEEE MTT-S Microwave Week, is considered the premier conference for publishing advances in the area of wireless IC design. The focus areas of last year’s meeting, held in San Francisco, CA, USA, cover a broad range of topics from 5G millimeter-wave-integrated systems to low-power wireless sensors, from spectrum sensing to mixed-signal power amplifiers, from terahertz to baseband circuits.
Autors: Danilo Manstretta;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: May 2017, volume: 52, issue:5, pages: 1183 - 1184
Publisher: IEEE
 
» Intrusion Detection and Ejection Framework Against Lethal Attacks in UAV-Aided Networks: A Bayesian Game-Theoretic Methodology
Abstract:
Advances in wireless communications and microelectronics have spearheaded the development of unmanned aerial vehicles (UAVs), which can be used to augment a ground network composed of sensors and/or vehicles in order to increase coverage, enhance the end-to-end delay, and improve data processing. While UAV-aided networks can potentially find applications in many areas, a number of issues, particularly security, have not been readily addressed. The intrusion detection system is the most commonly used technique to detect attackers. In this paper, we focus on addressing two main issues within the context of intrusion detection and attacker ejection in UAV-aided networks, namely, activation of the intrusion monitoring process and attacker ejection. In fact, when a large number of nodes activate their monitoring processes, the incurred overhead can be substantial and, as a consequence, degrades the network performance. Therefore, a tradeoff between the intrusion detection rate and overhead is considered in this work. It is not always the best strategy to eject a node immediately when it exhibits a bad sign of malicious activities since this sign could be provisional (the node may switch to a normal behavior in the future) or be simply due to noise or unreliable communications. Thus, a dilemma between detection and false positive rates is taken into account in this paper. We propose to address these two security issues by a Bayesian game model in order to accurately detect attacks (i.e., high detection and low false positive rates) with a low overhead. Simulation results have demonstrated that our proposed security game framework does achieve reliable detection.
Autors: Hichem Sedjelmaci;Sidi Mohammed Senouci;Nirwan Ansari;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: May 2017, volume: 18, issue:5, pages: 1143 - 1153
Publisher: IEEE
 
» Invasion of the hardware snatchers
Abstract:
In February 2014, the FBI charged a Florida man, Marc Heera, with selling a cloned version of the Hondata s300, a plug-in module for the engine computer that reads data from sensors in Honda cars and automatically adjusts the air-fuel mixture, idle speed, and other factors to improve performance. The plug-in also allows users to monitor the engine via Bluetooth and make their own adjustments. The clones certainly looked like the genuine product, but in fact they contained circuit boards that had likely been built in China, according to designs Heera had obtained through reverse engineering. Honda warned that cars using the counterfeits exhibited a number of problems, including random limits on engine rpm and, occasionally, failure to start. Devices that connect to an engine control unit (ECU) present particular safety concerns; researchers have demonstrated that, through ECU access, they could hijack a car's brakes and steering.
Autors: Mark M. Tehranipoor;Ujjwal Guin;Swarup Bhunia;
Appeared in: IEEE Spectrum
Publication date: May 2017, volume: 54, issue:5, pages: 36 - 41
Publisher: IEEE
 
» Inverse Moment Matching Based Analysis of Cooperative HARQ-IR Over Time-Correlated Nakagami Fading Channels
Abstract:
This paper analyzes the performance of cooperative hybrid automatic repeat request with incremental redundancy (HARQ-IR) and proposes a new approach of outage probability approximation for performance analysis. A general time-correlated Nakagami fading channel covering fast fading and Rayleigh fading as special cases is considered here. An efficient inverse moment matching method is proposed to approximate the outage probability in a closed form. The effect of approximation degree is theoretically analyzed to ease its selection. Moreover, diversity order of cooperative HARQ-IR is analyzed. It is proved that the diversity order is irrelevant to the time correlation coefficient , as long as , and full diversity from both spatial and time domains can be achieved by cooperative HARQ-IR under time-correlated fading channels. The accuracy of the analytical results is verified by computer simulations, and the results reveal that cooperative HARQ-IR scheme can benefit from high fading order and low channel time correlation. Optimal rate selection to maximize the long-term average throughput given a maximum allowable outage probability is finally discussed as one application of the analytical results.
Autors: Zheng Shi;Haichuan Ding;Shaodan Ma;Kam-Weng Tam;Su Pan;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 3812 - 3828
Publisher: IEEE
 
» Inverse Profiling of Inhomogeneous Subsurface Targets With Arbitrary Cross Sections Using Covariance Matrix Adaptation Evolution Strategy
Abstract:
The problem of subsurface inverse profiling of a 2-D inhomogeneous buried dielectric target is addressed in this letter. An iterative optimization technique is proposed that utilizes Covariance Matrix Adaption Evolutionary Strategy (CMA-ES) as its inverse solver and Method of Moments, using Conjugate Gradient-fast Fourier transform, as the forward solver. The numerical results indicate that CMA-ES, as its first reported implementation in buried target reconstruction, can successfully be applied to this challenging reconstruction problem. Also, comparison with Evolutionary Programming and Particle Swarm Optimization indicates that CMA-ES can significantly outperform the other two-optimization techniques in the inhomogeneous subsurface imaging. In addition, examples of various scenarios involving noisy data, lossy targets and multiple targets further demonstrate that CMA-ES can be considered as a robust, simple, and efficient optimization tool in the reconstruction of complex buried targets.
Autors: Maryam Hajebi;Ahmad Hoorfar;Elie Bou-Daher;Ahad Tavakoli;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 612 - 616
Publisher: IEEE
 
» Investigation of a Hump Phenomenon in Back-Channel-Etched Amorphous In-Ga-Zn-O Thin-Film Transistors Under Negative Bias Stress
Abstract:
The hump phenomenon along with a negative shift of threshold voltage emerging in the transfer characteristics of amorphous InGaZnO thin-film transistors under negative bias stress was investigated. Higher measurement temperature and larger bias voltage can induce more and faster hole injection, thus leading to the increased parasitic ON-state current and more negative shift of the threshold voltage. Nevertheless, the parasitic current is independent of the channel width, illustrating that the parasitic channel originates from the hole trapping near the IGZO edges along the channel length. Integrated Systems Engineering Technology Computer-aided Design simulation confirms that the electric field near the IGZO edge is relatively dense, and the direction is more conducive for the holes in IGZO to inject into passivation (PV), to gate insulator (GI), or at PV/GI interface.
Autors: Jianwen Yang;Po-Yung Liao;Ting-Chang Chang;Bo-Wei Chen;Hui-Chun Huang;Hsiao-Cheng Chiang;Wan-Ching Su;Qun Zhang;
Appeared in: IEEE Electron Device Letters
Publication date: May 2017, volume: 38, issue:5, pages: 592 - 595
Publisher: IEEE
 
» Investigation of a Nonlinear Energy Harvester
Abstract:
The use of nonlinear architectures for energy harvesting can significantly improve the efficiency of the conversion mechanism, as respect to the use of linear devices, especially when the mechanical energy is distributed over a wide frequency bandwidth. This is the case of energy harvesting form wideband vibrations. In this paper, performances of a piezoelectric energy harvester exploiting a snap-through buckling configuration are investigated. The device is supposed to switch between its stable states, where two piezoelectric transducers are positioned to implement the mechanical-to-electric conversion mechanism. A simple theoretical two-state model of the device is presented along with a complete experimental characterization aimed at investigating the mechanical and electrical behaviors of the device. The device is demonstrated to be capable of scavenging energy from vibration sources in the range 0.5–5 Hz, but could be exploited up to 15 Hz with an acceptable loss of efficiency. The bandwidth of the device is compatible with applications where the vibrations occur at low frequencies, e.g., in the case of a running human. In this paper, we demonstrate the viability of our setup for harvesting energy from mechanical vibrations. The device is seen to generate power up to at 5 Hz; the power is sufficient to operate a standard wireless sensor node. The conversion efficiency of the harvester in the range 0.5–5 Hz is from 13% up to 18% with an average of 15%.
Autors: Bruno Andò;Salvatore Baglio;Adi R. Bulsara;Vincenzo Marletta;Antonio Pistorio;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: May 2017, volume: 66, issue:5, pages: 1067 - 1075
Publisher: IEEE
 
» Investigation of Infrared Photo-Detection Through Subgap Density-of-States in a-InGaZnO Thin-Film Transistors
Abstract:
Amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) are investigated for a possible application to infrared (IR) photodetector through subgap density-of-states over the forbidden bandgap. The origin of the sub-bandgap( photo-response in a-IGZO TFTs is due to optically pumped electrons from the photo-responsive subgap states (-. Among the sub-bandgap lights, we investigate the reproducible IR photo-response in a-IGZO TFTs as a photodetector without the persistent photoconductivity (PPC) effect. In this letter, we characterize the IR photo-response mechanism through various optical and electrical measurements on the wavelength, optical power, bias-modulated quasi-Fermi level, and photo-responsive states. This result is expected to provide independent and/or integrated IR detector with transparent substrate combined with a-IGZO TFTs.
Autors: Heesung Lee;Junyeap Kim;Jaewon Kim;Seong Kwang Kim;Yongwoo Lee;Jae-Young Kim;Jun Tae Jang;Jaewon Park;Sung-Jin Choi;Dae Hwan Kim;Dong Myong Kim;
Appeared in: IEEE Electron Device Letters
Publication date: May 2017, volume: 38, issue:5, pages: 584 - 587
Publisher: IEEE
 
» Investigation of Mo/Ti/AlN/HfO2 High-k Metal Gate Stack for Low Power Consumption InGaAs NMOS Device Application
Abstract:
Use of the Mo/Ti/AlN/HfO2 metal/dielectric stack to increase the permittivity of HfO2 for low power consumption InGaAs-based MOSFET is investigated in this letter. The dielectric constant of HfO2 was found to increase by 47%, from 17 to 25, after Ti doping without affecting the interface trap density around the mid-gap of the MOSCAPs. A strong inversion behavior with low leakage current for the MOSCAP was also observed. The gate voltage needed to tune the Fermi level of InGaAs channel was found to be smaller for the Ti-doped HfO2 sample as compared with the sample with un-doped HfO2. The increase of the dielectric constant of HfO2 after Ti doping combined with the use of Ti gate metal, which has the work function level near the conduction band edge of InGaAs, makes the proposed Mo/Ti/HfO2 (Ti) stack ideal for future lowpower consumption InGaAs-based NMOS applications.
Autors: Huy Binh Do;Quang Ho Luc;Minh Thien Huu Ha;Sa Hoang Huynh;Tuan Anh Nguyen;Chenming Hu;Yueh Chin Lin;Edward Yi Chang;
Appeared in: IEEE Electron Device Letters
Publication date: May 2017, volume: 38, issue:5, pages: 552 - 555
Publisher: IEEE
 
» Investigation of Time-Domain Locus of SiGe HBTs in the Avalanche Region by Using the X-Parameter Measurement Under Large-Signal Drive
Abstract:
In this letter, the high-frequency avalanche effects of silicon germanium (SiGe) heterojunction bipolar transistors (HBTs) on time-domain locus characteristics based on the X-parameter measurement are presented and analyzed by applying the concept of the dead space theory for the first time. The measured X-parameters of the SiGe HBTs are utilized to obtain the time-domain waveform under large-signal drive in the impact ionization region. Input locus of the SiGe HBTs operating in the avalanche regime presents negative slope when compared with the positive slope in the active region. The rotation direction of the transfer locus at breakdown is also investigated.
Autors: Chie-In Lee;Yan-Ting Lin;Wei-Cheng Lin;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: May 2017, volume: 27, issue:5, pages: 464 - 466
Publisher: IEEE
 
» Investigation on Phase Shift Between Multiple Multiphase Windings in Flux-Switching Permanent Magnet Machines
Abstract:
Design rules of multiple multiphase winding configurations are investigated from the perspective of phase shift between adjacent winding sets in flux-switching permanent magnet (FSPM) machines. The relations between torque/rectified voltage and phase shift for any multiple multiphase winding topology are theoretically derived, directly showing the influence of phase shift on torque/rectified voltage harmonic components. It can be learned that the optimal phase shift for the lowest torque ripple and dc voltage oscillation depends on the winding types. Symmetrical winding is not always appropriate for any occasion. To verify the analytical results, the static characteristics of the dual three-phase, four three-phase, triplex three-phase, dual six-phase, and triplex four-phase FSPM machines with specific stator/rotor-pole combinations are studied by finite-element (FE) analysis. The FE-predicted dominant torque ripple and rectified voltage pulsation components for symmetrical and asymmetric phase shifts are in good agreement with the theoretical derivation. Prototypes are built and tested to verify the analytical and FE results.
Autors: Lingyun Shao;Wei Hua;Z. Q. Zhu;Wentao Huang;Zhongze Wu;Feng Li;Ming Cheng;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 1958 - 1970
Publisher: IEEE
 
» Investigation on the Dielectric Properties of Exfoliated Graphite-Silicon Carbide Nanocomposites and Their Absorbing Capability for the Microwave Radiation
Abstract:
The dielectric properties of the exfoliated graphite (EG) and sillicon carbide (SiC) powder based epoxy nanocomposites are investigated in the microwave frequency region for radar absorbers and stealth applications. The resulting composites are found to possess high dielectric constant and loss tangent in the X band (8.2–12.4 GHz) frequency region. It is observed that both the dielectric constant and the loss tangent of the nanocomposites increase as the weight percentages of the EG and SiC powders are increased. SiC powder is mainly introduced to enhance the thermal stability of the nanocomposites with the improved microwave absorption properties. The filler percentages of SiC nanopowder and EG powders are optimized for the wide band electromagnetic absorption (EM). Maximum EM absorption of 99.99% along with the minimum absorption value of 90% is achieved throughout X band frequency region. The resulting nanocomposites possess a very good agreement between the light weight, ease of processing, and cost. Furthermore, the complete morphological and thermal stability analyses are carried out for the nanocomposite samples which provide an insight into various mechanical and thermal properties. The observed electromagnetic, mechanical, and thermal properties of the proposed nanocomposites make them potential candidates as efficient electromagnetic absorbers in the microwave frequency region for various strategic applications.
Autors: Himangshu Bhusan Baskey;Sandeep Kumar Singh;Mohammad Jaleel Akhtar;Kamal K. Kar;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: May 2017, volume: 16, issue:3, pages: 453 - 461
Publisher: IEEE
 
» Invisible Hand: A Privacy Preserving Mobile Crowd Sensing Framework Based on Economic Models
Abstract:
Privacy issues are strongly impeding the development of mobile crowd sensing (MCS) applications. Under the current MCS framework, processes including bidding, task assignment, and sensed data uploading are all potentially risky for participants. As an effort toward this issue, we propose a framework that enhances the location privacy of MCS applications by reducing the bidding and assignment steps in the MCS cycle. Meanwhile, to reduce the unnecessary privacy loss while maintaining the required quality of service (QoS), economic theory is used to help both the service provider and participants to decide their strategies. We propose schemes based on both the Monopoly and Oligopoly models. In the former case, the participants cooperate to gain exclusive control of the supply of crowd sensing data, while the latter case is a state of limited competition. The parameters in different schemes are analyzed, and the strengths and weaknesses of both schemes are discussed. Additionally, the proposed schemes are evaluated by extensive simulations, and the results are discussed in detail.
Autors: Bo Liu;Wanlei Zhou;Tianqing Zhu;Haibo Zhou;Xiaodong Lin;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 4410 - 4423
Publisher: IEEE
 
» Irradiation of Radiation-Tolerant Single-Mode Optical Fibers at Cryogenic Temperature
Abstract:
Radiation effects at cryogenic temperature are investigated in two radiation-tolerant Fluorine-doped single-mode fibers originating from two different manufacturers. This paper presents measurements at room temperature (297 K) and at cryogenic temperature (16 K) of the radiation induced attenuation at 1312 nm and 1570 nm for both fibers. In addition to the massive increase of the optical attenuation at 16 K, the fiber is found to be in a frozen state where thermal bleaching and defect recombination no longer occurs. However, a long-term recovery, including the heating of the fiber from cryogenic temperature to room temperature, anneals a large amount of the defects created and brings the fiber back to almost its initial performance.
Autors: Jeremy Blanc;Daniel Ricci;Jochen Kuhnhenn;Udo Weinand;Olaf J. Schumann;
Appeared in: Journal of Lightwave Technology
Publication date: May 2017, volume: 35, issue:10, pages: 1929 - 1935
Publisher: IEEE
 
» Is Being Flexible Advantageous for Demands?
Abstract:
This paper analyzes the impacts of flexible demands on day-ahead market outcomes in a system with significant wind power production. We use a two-stage stochastic market-clearing model, where the first stage represents the day-ahead market and the second stage represents the real-time operation. On one hand, flexibility of demands is beneficial to the system as a whole since such flexibility reduces the operation cost, but on the other hand, shifts in demands from peak periods to off-peak periods may influence prices in such a way that demands may not be willing to provide flexibility. Specifically, we investigate the impacts of different degree of demand flexibility on day-ahead prices. A number of scenarios modeling the uncertainty associated with wind production at the operation stage, and nonconvexities due to start-up costs of generators and their minimum power outputs are taken into account.
Autors: Farzaneh Abbaspourtorbati;Antonio J. Conejo;Jianhui Wang;Rachid Cherkaoui;
Appeared in: IEEE Transactions on Power Systems
Publication date: May 2017, volume: 32, issue:3, pages: 2337 - 2345
Publisher: IEEE
 
» Is It Worth Responding to Reviews? Studying the Top Free Apps in Google Play
Abstract:
Up to this point, researchers have not explored the value of responding to user reviews of mobile apps. An analysis of reviews and responses for 10,713 of the top apps in Google Play showed that few developers responded to reviews. However, responding can have positive effects. Users changed their ratings 38.7 percent of the time following a response, with a median rating increase of 20 percent.
Autors: Stuart McIlroy;Weiyi Shang;Nasir Ali;Ahmed E. Hassan;
Appeared in: IEEE Software
Publication date: May 2017, volume: 34, issue:3, pages: 64 - 71
Publisher: IEEE
 
» Is the Sequence of SuperAlarm Triggers More Predictive Than Sequence of the Currently Utilized Patient Monitor Alarms?
Abstract:
Objective: Our previous studies have shown that “code blue” events can be predicted by SuperAlarm patterns that are multivariate combinations of monitor alarms and laboratory test results cooccurring frequently preceding the events but rarely among control patients. Deploying these patterns to the monitor data streams can generate SuperAlarm sequences. The objective of this study is to test the hypothesis that SuperAlarm sequences may contain more predictive sequential patterns than monitor alarms sequences. Methods: Monitor alarms and laboratory test results are extracted from a total of 254 adult coded and 2213 control patients. The training dataset is composed of subsequences that are sampled from complete sequences and then further represented as fixed-dimensional vectors by the term frequency inverse document frequency method. The information gain technique and weighted support vector machine are adopted to select the most relevant features and train a classifier to differentiate sequences between coded patients and control patients. Performances are assessed based on an independent dataset using three metrics: sensitivity of lead time (Sen@T), alarm frequency reduction rate (AFRR), and work-up to detection ratio (WDR). Results: The performance of 12-h-long sequences of SuperAlarm can yield a Sen@2 of 93.33%, an AFRR of 87.28%, and a WDR of 3.01. At an AFRR = 87.28%, Sen@2 for raw alarm sequences and discretized alarm sequences are 73.33% and 70.19%, respectively. At a WDR = 3.01, Sen@2 are 49.88% and 43.33%. Conclusion and Significance: The results demonstra- e that SuperAlarm sequences indeed outperform monitor alarm sequences and suggest that one can focus on sequential patterns from SuperAlarm sequences to develop more precise patient monitoring solutions.
Autors: Yong Bai;Duc Do;Quan Ding;Jorge Arroyo Palacios;Yalda Shahriari;Michele M. Pelter;Noel Boyle;Richard Fidler;Xiao Hu;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: May 2017, volume: 64, issue:5, pages: 1023 - 1032
Publisher: IEEE
 
» Iterative Reweighting Heterogeneous Transfer Learning Framework for Supervised Remote Sensing Image Classification
Abstract:
Supervised classification methods have been widely used in the hyperspectral remote sensing image analysis. However, they require a large number of training samples to guarantee good performance, which costs a large amount of time and human labor, motivating researchers to reuse labeled samples from the mass of pre-existing related images. Transfer learning methods can adapt knowledge in the existing images to solve the classification problem in new yet related images, and have drawn increasing interest in the remote sensing field. However, the existing methods in the RS field require that all the images share the same dimensionality, which prevents their practical application. This paper focuses on the transfer learning problem for heterogeneous spaces where the dimensions are different. We propose a novel iterative reweighting heterogeneous transfer learning (IRHTL) framework that iteratively learns a common space for the source and target data and conducts a novel iterative reweighting strategy to reweight the source samples. In each iteration, the heterogeneous data are first mapped into a common space by two projection functions based on a weighted support vector machine. Second, based on the common subspace, the source data are reweighted by using the iterative reweighting strategy and reused for the transferring, according to their relative importance. Experiments undertaken on three data sets confirmed the effectiveness and reliability of the proposed IRHTL method.
Autors: Xue Li;Liangpei Zhang;Bo Du;Lefei Zhang;Qian Shi;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: May 2017, volume: 10, issue:5, pages: 2022 - 2035
Publisher: IEEE
 
» Itinerant Routing in Elastic Optical Networks
Abstract:
We state a new problem of itinerant routing in elastic optical networks, which we define as the establishment and reconfiguration of an itinerant connection. In an itinerant connection, one of the connection end nodes is allowed to change. Itinerant routing could also be considered a form of connection restoration, where a connection has to be restored to a different end node. With the introduction and growth of mobile-network services and content-oriented services, and the eventual deployment of elastic optical networks, there is a need to support this itinerant routing in the elastic optical networks. We present and discuss two major use cases of the itinerant routing, and propose a novel reconfiguration algorithm. Our algorithm does not deteriorate the network performance, and requires half as many new links to configure in comparison with the complete shortest-path reconfiguration algorithm. The performance evaluation was carried out with 46 800 simulation runs using randomly-generated realistic transport networks.
Autors: Ireneusz Szcześniak;Artur Gola;Andrzej Jajszczyk;Andrzej R. Pach;Bożena Woźna-Szcześniak;
Appeared in: Journal of Lightwave Technology
Publication date: May 2017, volume: 35, issue:10, pages: 1868 - 1875
Publisher: IEEE
 
» ITU Spectrum Management Training Program: A Comprehensive Modular Framework for Formalized Professional Education
Abstract:
This article describes the concept and composition of the ITU Spectrum Management Training Program (SMTP) that was developed by the International Telecommunication Union and is currently being implemented under the auspices of the ITU Academy. SMTP was designed as a flexible ECTS-based modular framework for professional training that allows various degrees of immersion as well as different specialization paths toward a formal professional certification in the field of radio spectrum management. SMTP offers a solid and holistic system of professional education in both the theoretical and practical aspects of spectrum management as an important standardization activity supporting development of wireless communications. The ITU envisages SMTP eventually becoming a global �gold standard� for professional education in the highly specialized field of spectrum management. An essential differentiator for SMTP, compared to the limited offerings currently available for spectrum management training, is the formalized assessment of learning outcomes in terms of obtained professional skills and qualifications. Upon successful completion of SMTP, participants will be awarded a professional qualifications certificate by the ITU Academy or, possibly, a postgraduate professional education diploma of Master of Sciences from a partner university.
Autors: Arturas Medeisis;
Appeared in: IEEE Communications Magazine
Publication date: May 2017, volume: 55, issue:5, pages: 154 - 159
Publisher: IEEE
 
» Joint Assignment of Power, Routing, and Spectrum in Static Flexible-Grid Networks
Abstract:
This paper proposes a novel network planning strategy to jointly allocate physical layer resources together with the routing and spectrum assignment in transparent nonlinear flexible-grid optical networks with static traffic demands. The physical layer resources, such as power spectral density, modulation format, and carrier frequency, are optimized for each connection. By linearizing the Gaussian noise model, both an optimal formulation and a low complexity decomposition heuristic are proposed. Our methods minimize the spectrum usage of networks, while satisfying requirements on the throughput and quality of transmission. Compared with existing schemes that allocate a uniform power spectral density to all connections, our proposed methods relax this constraint and, thus, utilize network resources more efficiently. Numerical results show that by optimizing the power spectral density per connection, the spectrum usage can be reduced by around over uniform power spectral density schemes.
Autors: Li Yan;Erik Agrell;Madushanka Nishan Dharmaweera;Henk Wymeersch;
Appeared in: Journal of Lightwave Technology
Publication date: May 2017, volume: 35, issue:10, pages: 1766 - 1774
Publisher: IEEE
 
» Joint Beamforming for Multicell Multigroup Multicast With Per-Cell Power Constraints
Abstract:
This paper considers a joint beamforming design problem in the multicast broadcast single frequency network (MBSFN) scenario with multiple multicast groups that provide different multicast services. To solve the joint beamforming design among the cooperating base stations, which is also known as the joint processing scheme in the coordinated multipoint transmission (CoMP) defined in the long-term evolution-advanced (LTE-A) system, we devise different optimization techniques, such as semidefinite relaxation, fractional programming, and difference of convex (DC) programming. In this paper, per-cell power constraints are considered. In addition, we consider the design of higher rank transmission to increase the spectrum efficiency and the design of robust beamforming to alleviate performance degradation caused by imperfect channel state information. In the simulation results, we demonstrate the potential of the proposed algorithms in terms of the maximized minimum signal-to-interference plus noise ratio (SINR), and compare the proposed methods with the traditional MBSFN transmission scheme and the existing noncooperating multicast beamforming methods. The results show that the proposed methods, indeed, provide better performance. To complete the discussion, we also provide numerical results for the robust and nonrobust beamforming schemes in terms of the power consumption, feasibility ratio, and the histogram of the normalized SINR.
Autors: Guan-Wen Hsu;Binyue Liu;Hai-Han Wang;Hsuan-Jung Su;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 4044 - 4058
Publisher: IEEE
 
» Joint Compression of Near-Duplicate Videos
Abstract:
The expanding social network and multimedia technologies encourage more and more people to store and transmit information in visual format, such as image and video. However, the cost of this convenience brings about a shock to traditional video severs and exposes them under the risk of overloading. In the huge volume of online videos, there are a large amount of near-duplicate videos (NDVs). Although quite a number of research work have been proposed to detect NDVs, little research effort is made to compress these NDVs in a more effective manner than independent video compression. In this study, we make an in-depth exploration of the data redundancy of NDVs and propose a video analysis and coding framework to jointly compress NDVs. In order to employ the proposed NDV analysis and coding framework, a graph-based similar video grouping method and a number of preprocessing functions are designed to explore the correlation of visual information among NDVs and thus suit the requirement of joint video coding. Experimental results verify that the proposed NDV analysis and coding framework is able to effectively compress NDVs and thus save video data storage.
Autors: Hanli Wang;Tao Tian;Ming Ma;Jun Wu;
Appeared in: IEEE Transactions on Multimedia
Publication date: May 2017, volume: 19, issue:5, pages: 908 - 920
Publisher: IEEE
 
» Joint Device Positioning and Clock Synchronization in 5G Ultra-Dense Networks
Abstract:
In this paper, we address the prospects and key enabling technologies for highly efficient and accurate device positioning and tracking in fifth generation (5G) radio access networks. Building on the premises of ultra-dense networks as well as on the adoption of multicarrier waveforms and antenna arrays in the access nodes (ANs), we first formulate extended Kalman filter (EKF)-based solutions for computationally efficient joint estimation and tracking of the time of arrival (ToA) and direction of arrival (DoA) of the user nodes (UNs) using uplink reference signals. Then, a second EKF stage is proposed in order to fuse the individual DoA and ToA estimates from one or several ANs into a UN position estimate. Since all the processing takes place at the network side, the computing complexity and energy consumption at the UN side are kept to a minimum. The cascaded EKFs proposed in this article also take into account the unavoidable relative clock offsets between UNs and ANs, such that reliable clock synchronization of the access-link is obtained as a valuable by-product. The proposed cascaded EKF scheme is then revised and extended to more general and challenging scenarios where not only the UNs have clock offsets against the network time, but also the ANs themselves are not mutually synchronized in time. Finally, comprehensive performance evaluations of the proposed solutions on a realistic 5G network setup, building on the METIS project based outdoor Madrid map model together with complete ray tracing based propagation modeling, are provided. The obtained results clearly demonstrate that by using the developed methods, sub-meter scale positioning and tracking accuracy of moving devices is indeed technically feasible in future 5G radio access networks operating at sub-6 GHz frequencies, despite the realistic assumptions related to clock offsets and potentially even under unsynchronized network elements.
Autors: Mike Koivisto;Mário Costa;Janis Werner;Kari Heiska;Jukka Talvitie;Kari Leppänen;Visa Koivunen;Mikko Valkama;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: May 2017, volume: 16, issue:5, pages: 2866 - 2881
Publisher: IEEE
 
» Joint Dimming and Communication Design for Visible Light Communication
Abstract:
Multi-pulse position modulation (M-PPM) is advantageous in a visible light communication system due to its overall satisfactory performance in spectrum efficiency and dimming control. In this letter, we consider the joint dimming and communication design with M-PPM. We provide a model for the dimming control and address the balance between the dimming loss minimization and the transmission rate maximization. The dimming loss is modeled by the quantization loss within the dimming range for the discrete transmission power levels. The transmission rate is evaluated by the channel capacity. We propose two optimization formulations on the dimming requirement service and the transmission rate maximization. Numerical results show that the objective loss function may increase as either the lower limit of the dimming range approaches zero or the upper limit approaches the peak transmission power.
Autors: Shun Lou;Chen Gong;Nan Wu;Zhengyuan Xu;
Appeared in: IEEE Communications Letters
Publication date: May 2017, volume: 21, issue:5, pages: 1043 - 1046
Publisher: IEEE
 
» Joint Precoding and RRH Selection for User-Centric Green MIMO C-RAN
Abstract:
This paper jointly optimizes the precoding matrices and the set of active remote radio heads (RRHs) to minimize the network power consumption for a user-centric cloud radio access network, where both the RRHs and users have multiple antennas and each user is served by its nearby RRHs. Both users’ rate requirements and per-RRH power constraints are considered. Due to these conflicting constraints, this optimization problem may be infeasible. In this paper, we propose to solve this problem in two stages. In Stage I, a low-complexity user selection algorithm is proposed to find the largest subset of feasible users. In Stage II, a low-complexity algorithm is proposed to solve the optimization problem with the users selected from Stage I. Specifically, the re-weighted -norm minimization method is used to transform the original problem with non-smooth objective function into a series of weighted power minimization (WPM) problems, each of which can be solved by the weighted minimum mean square error (WMMSE) method. The solution obtained by the WMMSE method is proved to satisfy the Karush-Kuhn-Tucker conditions of the WPM problem. Moreover, a low-complexity algorithm based on Newton’s method and the gradient descent method is developed to update the precoder matrices in each iteration of the WMMSE method. Simulation results demonstrate the rapid convergence of the proposed algorithms and the benefits of equipping multiple antennas at the user side. Moreover, the proposed algorithm is shown to achieve near-optimal performance in terms of NPC.
Autors: Cunhua Pan;Huiling Zhu;Nathan J. Gomes;Jiangzhou Wang;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: May 2017, volume: 16, issue:5, pages: 2891 - 2906
Publisher: IEEE
 
» Joint Relay Beamforming Design for Multilevel Nondistributed and Distributed Amplify-and-Forward Relay Networks
Abstract:
This paper considers both nondistributed and distributed multilevel amplify-and-forward (AF) wireless relay networks. For a fair comparison, the nondistributed multilevel AF relay network consists of a one-source–one-destination pair and a relay at each level with multiple antennas, whereas the distributed network consists of a one-source–one-destination pair and multiple distributed relays at each level with a single antenna at each relay. In this paper, relay beamforming matrices are determined for both networks based on the minimum mean square error (MMSE) criterion. During data transmission, power is independently and individually constrained at the relays at each level. Finally, an iterative algorithm is proposed to solve the desired optimization problem.
Autors: Yeonggyu Shim;Kanghee Lee;Hyuncheol Park;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 4443 - 4448
Publisher: IEEE
 
» Joint Symbol and Chip Synchronization for a Burst-Mode-Communication Superregenerative MSK Receiver
Abstract:
In this paper we describe a superregenerative (SR) MSK receiver able to operate in a burst-mode framework where synchronization is required for each packet. The receiver is based on an SR oscillator which provides samples of the incoming instantaneous phase trajectories. We develop a simple yet effective technique to achieve joint chip and symbol synchronization within the time limits of a suitable preamble. We develop some general results and focus on the case of the IEEE 802.15.4 MSK physical layer. We provide details on a VHDL implementation on an FPGA where the most complex digital processing block is an accumulator. Simulation and experimental results are provided to validate the described technique.
Autors: Alexis López-Riera;Francisco del Águila-López;Pere Palá-Schönwälder;Jordi Bonet-Dalmau;Rosa Giralt-Mas;F. Xavier Moncunill-Geniz;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: May 2017, volume: 64, issue:5, pages: 1260 - 1269
Publisher: IEEE
 
» Joint Transceiver and Offset Design for Visible Light Communications With Input-Dependent Shot Noise
Abstract:
In this paper, we investigate the problem of the joint transceiver and offset design for point-to-point multiple-input–multiple-output (MIMO) and multiple user multiple-input–single-output visible light communication (VLC) systems. Both uplink and downlink multi-user scenarios are considered. The shot noise induced by the incoming signals is considered, leading to a more realistic MIMO VLC channel model. Under key lighting constraints, we formulate non-convex optimization problems aimed at minimizing the sum mean squared error. To optimize the transceiver and the offset jointly, a gradient projection-based procedure is resorted to. When only imperfect channel state information is available, a semidefinite programming-based scheme is proposed to obtain robust transceiver and offset. The proposed method is shown to non-trivially outperform the conventional scaled zero forcing and singular. value decomposition-based equalization methods. The robust scheme works particularly well when the signal is much stronger than the noise.
Autors: Qian Gao;Chen Gong;Zhengyuan Xu;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: May 2017, volume: 16, issue:5, pages: 2736 - 2747
Publisher: IEEE
 
» Jointly Optimized Reed–Muller Codes for Multilevel Multirelay Coded-Cooperative VANETS
Abstract:
In this paper, we present the well-known Reed–Muller (RM) codes for multilevel multirelay vehicular adhoc networks, which can enjoy coded-cooperation among network nodes. At first, we present the code construction principles for a single node/relay scenario and then extend the design principles to the two-level two-relay and, finally, to multilevel multirelay scenarios. The term “level” refers to the fact that different order RM code is used at each relaying node. Plotkin's construction is exploited to utilize RM codes in such coded-cooperative schemes. To achieve an optimum code at the destination node, proper encoding strategy needs to be employed at the relay node. Therefore, we propose a design criteria and an efficient algorithm for proper bit selection at the relay nodes to achieve the best possible code at the destination. It is observed that the increase in the number of levels as well as relays result in better channel code at the destination, as compared to the lesser number of relays, however, at the cost of increased decoding complexity. The channels considered to analyze the bit error rate (BER) performances of proposed coded-cooperative schemes are fast and slow Rayleigh fading channels. At the destination, soft decision maximum likelihood decoding is employed. Numerical simulations show that the single-relay RM coded-cooperative scheme provides significant BER performance gains over the noncooperative and state-of-the-art distributed turbo coded-cooperative schemes under identical conditions.
Autors: Saqib Ejaz;Yang FengFan;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 4017 - 4028
Publisher: IEEE
 
» JPSS-1VIIRS Prelaunch Polarization Testing and Performance
Abstract:
The Visible Infrared Imaging Radiometer Suite (VIIRS) instruments onboard both the Suomi National Polar-orbiting Partnership (S-NPP) and the first Joint Polar Satellite System (JPSS-1) spacecraft, with launch dates of October 2011 and late 2016, respectively, have polarization sensitivity, which affects the at-aperture radiometric calibration. This polarization sensitivity is caused by optics within VIIRS having different reflectance and transmission values as a function of at-aperture photon electric field orientation and is spectrally, spatially, and scan angle dependent. Characterization of the instrument's polarization sensitivity for each visible near-infrared (VNIR) band and detector was performed prelaunch at multiple cross-track scan angles. The resultant characterization parameters are VIIRS polarization amplitude and phase that enable the at-aperture radiance to be adjusted based on its polarization characteristics. The sensor requirements are that the polarization amplitude for scan angles within ±45° of nadir be below 2.5%-3% depending on the band and have an uncertainty in both amplitude and phase of less than 0.5%. The S-NPP VIIRS passed these requirements with band M1 (412 nm) having the smallest margin (~8%). Modification to the VNIR bandpass filter designs on JPSS-1 was performed to reduce out-of-band response leaks observed prelaunch on S-NPP. An unintended consequence of the spectral bandpass modification was an increase in the polarization sensitivity by roughly a factor of 2 for some VNIR bands. The degree to which JPSS-1 VIIRS polarization sensitivity characterization results exceed the sensor specifications and comparisons with S-NPP will be discussed.
Autors: David Moyer;Jeff McIntire;James Young;James K. McCarthy;Eugene Waluschka;Xiaoxiong Xiong;Frank J. De Luccia;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: May 2017, volume: 55, issue:5, pages: 2463 - 2476
Publisher: IEEE
 
» Keep It Simple: Bidding for Servers in Today's Cloud Platforms
Abstract:
Public clouds now offer computing services with a variety of pricing schemes. Spot servers, which offer large cost savings, are an increasingly popular platform on which applications are being deployed. Spot servers are dynamically priced and require users to submit a bid. In this article, the authors show the effect of bidding on application cost and availability when running on spot servers. Based on their analysis, they present simple and effective bidding strategies for users and provide motivation for new research directions in cloud resource management and fault tolerance.
Autors: Prateek Sharma;David Irwin;Prashant Shenoy;
Appeared in: IEEE Internet Computing
Publication date: May 2017, volume: 21, issue:3, pages: 88 - 92
Publisher: IEEE
 
» Kernel Fused Representation-Based Classifier for Hyperspectral Imagery
Abstract:
In this letter, we propose a kernel fused representation-based classifier (KFRC) for hyperspectral images (HSIs), which combines sparse representation (SR) and collaborative representation (CR) into a unified kernel representation-based classification framework. First, we present two individual kernel methods, i.e., kernel SR (KSR) and kernel CR (KCR), which kernelize the representation methods by projecting the samples into a high-dimensional kernel space to improve the samples separability between different classes. Once obtaining the two kernel representation coefficients, KFRC attempts to achieve a balance between KSR and KCR via an adjusting parameter in the kernel residual domain. Subsequently, the class label of each test sample is determined by the minimum residual for each class. Experimental results on two HSIs demonstrate the proposed kernel fused method performs better than the other state-of-the-art representation-based classifiers.
Autors: Le Gan;Peijun Du;Junshi Xia;Yaping Meng;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 684 - 688
Publisher: IEEE
 
» Knowledge Base Semantic Integration Using Crowdsourcing
Abstract:
The semantic Web has enabled the creation of a growing number of knowledge bases (KBs), which are designed independently using different techniques. Integration of KBs has attracted much attention as different KBs usually contain overlapping and complementary information. Automatic techniques for KB integration have been improved but far from perfect. Therefore, in this paper, we study the problem of knowledge base semantic integration using crowd intelligence. There are both classes and instances in a KB, in our work, we propose a novel hybrid framework for KB semantic integration considering the semantic heterogeneity of KB class structures. We first perform semantic integration of the class structures via crowdsourcing, then apply the blocking-based instance matching approach according to the integrated class structure. For class structure (taxonomy) semantic integration, the crowd is leveraged to help identifying the semantic relationships between classes to handle the semantic heterogeneity problem. Under the conditions of both large scale KBs and limited monetary budget for crowdsourcing, we formalize the class structure (taxonomy) semantic integration problem as a Local Tree Based Query Selection (LTQS) problem. We show that the LTQS problem is NP-hard and propose two greedy-based algorithms, i.e., static query selection and adaptive query selection. Furthermore, the KBs are usually of large scales and have millions of instances, direct pairwise-based instance matching is inefficient. Therefore, we adopt the blockingbased strategy for instance matching, taking advantage of the class structure (taxonomy) integration result. The experiments on real large scale KBs verify the effectiveness and efficiency of the proposed approaches.
Autors: Rui Meng;Lei Chen;Yongxin Tong;Chen Zhang;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: May 2017, volume: 29, issue:5, pages: 1087 - 1100
Publisher: IEEE
 
» Land Contamination Analysis of SMOS Brightness Temperature Error Near Coastal Areas
Abstract:
For Soil Moisture And Ocean Salinity (SMOS) data, significant errors exist near coastal areas because of the contamination by the nearby land. For analyzing the origin of the land contamination, in this letter, it is found, from the global map of SMOS data error, that although the SMOS data error due to land contamination near coasts varies in different regions, the characteristic that the error increases significantly in proximity to land is similar in global scope. The detailed analysis of SMOS brightness temperature (TB) error in the selected area reveals a decreasing trend with the increase of the distance to coast (DC). An SMOS TB measurement model according to geophysical parameters of the selected area and SMOS/microwave imaging radiometer aperture synthesis antenna array is established to analyze the origin of the TB error variation due to land contamination. The simulation results, which agree with the SMOS TB data analysis, show that within 40 km of DC, TB error is large and decreases sharply from ~60 to ~4 K with the increase of DC, since the mainlobe of the antenna array is departing from land to ocean; during 40–400 km of DC, TB error decreases smoothly from ~4 to ~0.15 K, since the lower near sidelobes are observing and leaving land; TB error slightly decreases to 0 from 400 to 800 km when the lower far sidelobes leave land. The study of the origin of land contamination on ocean TB will be helpful for improving the observation of salinity near coastal areas.
Autors: Yan Li;Qingxia Li;Hailiang Lu;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 587 - 591
Publisher: IEEE
 
» Land-Use Classification via Extreme Learning Classifier Based on Deep Convolutional Features
Abstract:
One of the challenging issues in high-resolution remote sensing images is classifying land-use scenes with high quality and accuracy. An effective feature extractor and classifier can boost classification accuracy in scene classification. This letter proposes a deep-learning-based classification method, which combines convolutional neural networks (CNNs) and extreme learning machine (ELM) to improve classification performance. A pretrained CNN is initially used to learn deep and robust features. However, the generalization ability is finite and suboptimal, because the traditional CNN adopts fully connected layers as classifier. We use an ELM classifier with the CNN-learned features instead of the fully connected layers of CNN to obtain excellent results. The effectiveness of the proposed method is tested on the UC-Merced data set that has 2100 remotely sensed land-use-scene images with 21 categories. Experimental results show that the proposed CNN-ELM classification method achieves satisfactory results.
Autors: Qian Weng;Zhengyuan Mao;Jiawen Lin;Wenzhong Guo;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 704 - 708
Publisher: IEEE
 
» Lane Change Maneuvers for Automated Vehicles
Abstract:
By considering a lane change maneuver as primarily a longitudinal motion planning problem, this paper presents a lane change maneuver algorithm with a pragmatic approach to determine an inter-vehicle traffic gap and time instance to perform the maneuver. The proposed approach selects an appropriate inter-vehicle traffic gap and time instance to perform the lane change maneuver by simply estimating whether there might exist a longitudinal trajectory that allows the automated vehicle to safely perform the maneuver. The lane change maneuver algorithm then proceeds to solve two loosely coupled convex quadratic programs to obtain the longitudinal trajectory to position the automated vehicle in the selected inter-vehicle traffic gap at the desired time instance and the corresponding lateral trajectory. Simulation results demonstrate the capability of the proposed approach to select an appropriate inter-vehicle traffic gap and time instance to initialize the lateral motion of a lane change maneuver in various traffic scenarios. The real-time ability of the lane change maneuver algorithm to generate safe and smooth trajectories is shown by experimental results of a Volvo V60 performing automated lane change maneuvers on a test track.
Autors: Julia Nilsson;Mattias Brännström;Erik Coelingh;Jonas Fredriksson;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: May 2017, volume: 18, issue:5, pages: 1087 - 1096
Publisher: IEEE
 
» Large-Scale Smart Grids: Recipes for Successful Integrations [From the Editor]
Abstract:
Presents the introductory editorial for this issue of the publication.
Autors: Michael Henderson;
Appeared in: IEEE Power and Energy Magazine
Publication date: May 2017, volume: 15, issue:3, pages: 4 - 6
Publisher: IEEE
 
» Large-Scale VM Placement with Disk Anti-Colocation Constraints Using Hierarchical Decomposition and Mixed Integer Programming
Abstract:
As computational clouds offer increasingly sophisticated services, there is a dramatic increase in the variety and complexity of virtual machine (VM) placement problems. In this paper, we consider a VM placement problem with a special type of anti-colocation requirements—disk anti-colocation—which stipulate that, for every VM assigned to a PM (physical machine), its virtual disks should be spread out across the physical disks of the PM. Once such a requirement is met, the users of the VM can expect improved disk I/O performance. There will also be improvement in fault tolerance and availability. For scalable solutions, we propose a method that combines hierarchical decomposition with mixed integer programming (MIP), where the basic building blocks are independent, small MIP subproblems. We provide experimental results to demonstrate the effectiveness of the proposed method. We show that it is scalable and achieves high performance with respect to the optimization objective.
Autors: Ye Xia;Mauricio Tsugawa;Jose A. B. Fortes;Shigang Chen;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: May 2017, volume: 28, issue:5, pages: 1361 - 1374
Publisher: IEEE
 
» Laser Diode Current Driver With $(1-t/T)^{-1}$ Time Dependence in 0.35- $mutext{m}$ BiCMOS Technology for Quantum Random Number Generators
Abstract:
A laser diode current driver with time dependence in 0.35- BiCMOS technology is presented in this brief. It is intended for application in optical quantum random number generators. The current driver is based on the balanced type of a bipolar junction transistor translinear loop with a sawtooth current as one of its inputs. The controllability of the frequency, shape, amplitude, and dc level of the current pulses is provided. The achievable frequency bandwidth of the current pulses is up to 100 MHz. A relative error of the measured waveform at a frequency of 25 MHz is smaller than 3% in 97.4% of the time period of interest.
Autors: Nikša Tadić;Bernhard Goll;Horst Zimmermann;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: May 2017, volume: 64, issue:5, pages: 510 - 514
Publisher: IEEE
 
» Laser-Assisted Counter-Facing Plasma Focus Device as a Light Source for EUV Lithography
Abstract:
A pair of plasma focus devices was operated with a counter-facing configuration. The focus electrode consisted of six cathodes and a center anode, drove a multichannel discharge. The multichannel discharges were triggered by a YAG laser, which also supplied lithium plasma as the radiation source. A high energy density lithium plasma was formed in the center of focus electrodes, which emitted radiation in an extreme ultraviolet region through the Lyman- (2p-1s) transition of hydrogenlike lithium ions for pulse duration of more than microsecond. A proof of principle experiment and the latest advances toward realization of a high-average power system are shown.
Autors: Tatsuya Sodekoda;Shintaro Kurata;Hajime Kuwabara;Tomoaki Kawasaki;Shotaro Kittaka;Kazuhiko Horioka;
Appeared in: IEEE Transactions on Plasma Science
Publication date: May 2017, volume: 45, issue:5, pages: 836 - 842
Publisher: IEEE
 
» Lasing Polarization Characteristics in 1.55- $mu text{m}$ Spin-Injected VCSELs
Abstract:
Circular polarization characteristics in vertical-cavity surface-emitting lasers (VCSELs) with InAlGaAs quantum wells injected by spin-polarized electrons were investigated. A degree of circular polarization of 10% was obtained in a reduced birefringence VCSEL at a lasing wavelength of 1544 nm at room temperature under optical pumping of spin-polarized electrons. Strong birefringence originally introduced to stabilize the lasing polarization was confirmed to be undesirable for a high degree of circular polarization in spin-injected VCSELs. A spin-flip rate equation analysis fairly reproduced the experimental results and supported our conclusions.
Autors: Nobuhide Yokota;Ryutaro Takeuchi;Hiroshi Yasaka;Kazuhiro Ikeda;
Appeared in: IEEE Photonics Technology Letters
Publication date: May 2017, volume: 29, issue:9, pages: 711 - 714
Publisher: IEEE
 
» Lattice Coding and Decoding for Multiple-Antenna Ergodic Fading Channels
Abstract:
For ergodic fading, a lattice coding and decoding strategy is proposed and its performance is analyzed for the single-input single-output (SISO) and multiple-input multiple-output (MIMO) point-to-point channel as well as the multiple-access channel (MAC), with channel state information available only at the receiver (CSIR). At the decoder a novel strategy is proposed consisting of a time-varying equalization matrix followed by decision regions that depend only on channel statistics, not individual realizations. Our encoder has a similar structure to that of Erez and Zamir. For the SISO channel, the gap to capacity is bounded by a constant under a wide range of fading distributions. For the MIMO channel under Rayleigh fading, the rate achieved is within a gap to capacity that does not depend on the signal-to-noise ratio (SNR), and diminishes with the number of receive antennas. The analysis is extended to the -user MAC where similar results hold. Achieving a small gap to capacity while limiting the use of CSIR to the equalizer highlights the scope for efficient decoder implementations, since decision regions are fixed, i.e., independent of channel realizations.
Autors: Ahmed Hindy;Aria Nosratinia;
Appeared in: IEEE Transactions on Communications
Publication date: May 2017, volume: 65, issue:5, pages: 1873 - 1885
Publisher: IEEE
 
» Leader-Follower Synchronization of Euler-Lagrange Systems With Time-Varying Leader Trajectory and Constrained Discrete-Time Communication
Abstract:
This paper addresses the leader-follower synchronization problem of uncertain networked Euler-Lagrange systems under directed interconnection graphs in the presence of communication constraints. We present an adaptive distributed control algorithm such that a group of Euler-Lagrange systems asymptotically synchronize their states to those of a dynamic leader with a time-varying trajectory. The information exchange between all systems in the network is assumed to be discrete in time, intermittent, and subject to irregular communication delays and possible packets dropouts. It is shown that leader-follower synchronization is reached for arbitrary characteristics of the communication process provided that the directed interconnection graph contains a spanning tree. Simulation results are given to illustrate the effectiveness of the proposed control scheme.
Autors: Abdelkader Abdessameud;Abdelhamid Tayebi;Ilia G. Polushin;
Appeared in: IEEE Transactions on Automatic Control
Publication date: May 2017, volume: 62, issue:5, pages: 2539 - 2545
Publisher: IEEE
 
» Leaky-Wave Antenna Array With a Power-Recycling Feeding Network for Radiation Efficiency Improvement
Abstract:
A novel kind of leaky-wave antenna (LWA) array with a power-recycling feeding network is proposed for radiation efficiency improvement. The antenna array is constructed by two kinds of substrate-integrated waveguide LWAs with different periodic slots. One kind of the LWA is designed to work on the fundamental () wave and radiates in the forward direction. The other one is designed to work on the −1th () spatial harmonic and radiates in the backward direction. The nonradiated power at the end of one kind of the LWA is directly fed into the other (adjacent) kind of the LWA in reverse direction. Therefore, the reversed feeding can compensate the opposite radiation direction of the two kinds of LWAs, and result in a superposition of radiation. So, both the gain and radiation efficiency of the antenna can be significantly improved, while the array maintains a compact size as those of traditional planar arrays. Simulation results are compared with measurement results to validate the proposed concept of integrating different leaky-wave structures into one array.
Autors: Yunjie Geng;Junhong Wang;Yujian Li;Zheng Li;Meie Chen;Zhan Zhang;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: May 2017, volume: 65, issue:5, pages: 2689 - 2694
Publisher: IEEE
 
» Learning Geographical and Mobility Factors for Mobile Application Recommendation
Abstract:
With myriad features and functionalities, mobile app users have the option to run different types of apps when they move to different locations. For a specific place, the decision process involved in choosing a mobile app can be complex and influenced by various factors, such as app popularity, user preferences, geographical influences, and user mobility behaviors. Although several researchers have studied recommendation in mobile apps, they omitted an integrated analysis of the joint effect of multiple factors from a geographical perspective. This article proposes a novel location-based probabilistic factor analysis mechanism that considers multiple factors to help people visiting a new location get an appropriate mobile app recommendation. In particular, the authors model mobile app usage from a geographical perspective. Experimental results on real mobile usage data show that the proposed recommendation method outperforms baseline algorithms by 30 percent.
Autors: Konglin Zhu;Lin Zhang;Achille Pattavina;
Appeared in: IEEE Intelligent Systems
Publication date: May 2017, volume: 32, issue:3, pages: 36 - 44
Publisher: IEEE
 
» Learning Hierarchical Decision Trees for Single-Image Super-Resolution
Abstract:
Sparse representation has been extensively studied for image super-resolution (SR), and it achieved great improvement. Deep-learning-based SR methods have also emerged in the literature to pursue better SR results. In this paper, we propose to use a set of decision tree strategies for fast and high-quality image SR. Our proposed SR using decision tree (SRDT) method takes the divide-and-conquer strategy, which performs a few simple binary tests to classify an input low-resolution (LR) patch into one of the leaf nodes and directly multiplies this LR patch with the regression model at that leaf node for regression. Both the classification process and the regression process take an extremely small amount of computation. To further boost the SR results, we introduce a SR using hierarchical decision trees (SRHDT) method, which cascades multiple layers of decision trees for SR and progressively refines the estimated high-resolution image. Inspired by the random forests approach, which combines regression models from an ensemble of decision trees, we propose to fuse regression models from relevant leaf nodes within the same decision tree to form a more robust approach. The SRHDT method with fused regression model (SRHDT_f) improves further the SRHDT method by 0.1-dB in PNSR. Our experimental results show that our initial approach, the SRDT method, achieves SR results comparable to those of the sparse-representation-based method and the deep-learning-based method, but our method is much faster. Furthermore, our enhanced version, the SRHDT_f method, achieves more than 0.3-dB higher PSNR than that of the A+ method, which is the state-of-the-art method in SR.
Autors: Jun-Jie Huang;Wan-Chi Siu;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: May 2017, volume: 27, issue:5, pages: 937 - 950
Publisher: IEEE
 
» Learning Immune-Defectives Graph Through Group Tests
Abstract:
This paper deals with an abstraction of a unified problem of drug discovery and pathogen identification. Pathogen identification involves the identification of disease-causing biomolecules. Drug discovery involves finding chemical compounds, called lead compounds, that bind to pathogenic proteins and eventually inhibit the function of the protein. In this paper, the lead compounds are abstracted as inhibitors, pathogenic proteins as defectives, and the mixture of “ineffective” chemical compounds and non-pathogenic proteins as normal items. A defective could be immune to the presence of an inhibitor in a test. So, a test containing a defective is positive if it does not contain its “associated” inhibitor. The goal of this paper is to identify the defectives, inhibitors, and their “associations” with high probability, or in other words, learn the immune defectives graph (IDG) efficiently through group tests. We propose a probabilistic non-adaptive pooling design, a probabilistic two-stage adaptive pooling design, and decoding algorithms for learning the IDG. For the two-stage adaptive-pooling design, we show that the sample complexity of the number of tests required to guarantee recovery of the inhibitors, defectives, and their associations with high probability, i.e., the upper bound, exceeds the proposed lower bound by a logarithmic multiplicative factor in the number of items. To be precise, lower and upper bounds of and tests, respectively, are identified for classifying inhibitors and defectives amongst $n$ items, and identifying their associations. For the non-adaptive pooling design, we show that the upper bound (given by tests) exceeds the proposed lower bound (given by tests) by at most a logarithmic multiplicative factor in the number of items.
Autors: Abhinav Ganesan;Sidharth Jaggi;Venkatesh Saligrama;
Appeared in: IEEE Transactions on Information Theory
Publication date: May 2017, volume: 63, issue:5, pages: 3010 - 3028
Publisher: IEEE
 
» Learning Mobile Communications Standards through Flexible Software Defined Radio Base Stations
Abstract:
Mobile communications are today widespread and contribute to the development of our society. Every day new devices include some means of wireless transmission, which is becoming ubiquitous with the Internet of Things. These systems are standardized by international organizations such as the IEEE, 3GPP, and ETSI, among others. Even though knowledge of wireless standards is key to the understanding of these systems, wireless communications are quite often taught in engineering degrees in a traditional way, without much emphasis on the standardization. Moreover, strong focus is often placed on the theoretical performance analysis rather than on practical implementation aspects. In contrast, most of the current applications make extensive use of mobile data, and the global users' satisfaction is highly correlated with the mobile data throughput. Thus, modern wireless engineers need to have deep insight on the standards that define the mobile transmission systems, and this knowledge is not acquired following the traditional theoretical teaching schemes. In this article, a new learning approach is described. This novel paradigm is based on a new flexible hardware/software platform (FRAMED-SOFT), which is also detailed. Although the article is focused on two wireless standards, GSM and UMTS, the work discussed in this article can easily be extended to other standards of interest, such as LTE and beyond, WiFi, and WiMAX.
Autors: Victor P. Gil Jimenez;Alejandro Lancho Serrano;Borja Genoves Guzman;Ana Garcia Armada;
Appeared in: IEEE Communications Magazine
Publication date: May 2017, volume: 55, issue:5, pages: 116 - 123
Publisher: IEEE
 
» Learning on Big Graph: Label Inference and Regularization with Anchor Hierarchy
Abstract:
Several models have been proposed to cope with the rapidly increasing size of data, such as Anchor Graph Regularization (AGR). The AGR approach significantly accelerates graph-based learning by exploring a set of anchors. However, when a dataset becomes much larger, AGR still faces a big graph which brings dramatically increasing computational costs. To overcome this issue, we propose a novel Hierarchical Anchor Graph Regularization (HAGR) approach by exploring multiple-layer anchors with a pyramid-style structure. In HAGR, the labels of datapoints are inferred from the coarsest anchors layer by layer in a coarse-to-fine manner. The label smoothness regularization is performed on all datapoints, and we demonstrate that the optimization process only involves a small-size reduced Laplacian matrix. We also introduce a fast approach to construct our hierarchical anchor graph based on an approximate nearest neighbor search technique. Experiments on million-scale datasets demonstrate the effectiveness and efficiency of the proposed HAGR approach over existing methods. Results show that the HAGR approach is even able to achieve a good performance within 3 minutes in an 8-million-example classification task.
Autors: Meng Wang;Weijie Fu;Shijie Hao;Hengchang Liu;Xindong Wu;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: May 2017, volume: 29, issue:5, pages: 1101 - 1114
Publisher: IEEE
 
» Learning to Predict High-Quality Edge Maps for Room Layout Estimation
Abstract:
The goal of room layout estimation is to predict the three-dimensional box that represents the room spatial structure from a monocular image. In this paper, a deconvolution network is trained first to predict the edge map of a room image. Compared to the previous fully convolutional networks, the proposed deconvolution network has a multilayer deconvolution process that can refine the edge map estimate layer by layer. The deconvolution network also has fully connected layers to aggregate the information of every region throughout the entire image. During the layout generation process, an adaptive sampling strategy is introduced based on the obtained high-quality edge maps. Experimental results prove that the learned edge maps are highly reliable and can produce accurate layouts of room images.
Autors: Weidong Zhang;Wei Zhang;Kan Liu;Jason Gu;
Appeared in: IEEE Transactions on Multimedia
Publication date: May 2017, volume: 19, issue:5, pages: 935 - 943
Publisher: IEEE
 
» Leveraging Game Theory to Achieve Efficient Attack-Aware Service Provisioning in EONs
Abstract:
Multidomain elastic optical networks (MD-EONs) help to improve network scalability, extend service coverage, and facilitate good interoperability to orchestrate administrative domains managed by different carriers. Since the users in other domains can launch cross-domain physical-layer attacks to a domain, this paper studies the problem of attack-aware service provisioning in one domain of an MD-EON. We consider a realistic scenario that does not treat all the interdomain lightpaths as malicious ones, and try to arrange the lightpaths’ routing and spectrum assignment (RSA) schemes with the help of the game theory to balance the spectrum utilization and security-level of the domain well. Specifically, we define a two-player Bayesian game to represent the provisioning procedure for each interdomain request, and design the game strategies and utility functions for the players (i.e., the domain manager and the user from other domains). Then, we formulate a nonlinear programming model, solve the game with it to obtain a Bayesian Nash equilibrium (BNE), and determine the best strategies for the players based on the BNE. Finally, with the game model, we propose a game-assisted RSA algorithm to achieve attack-aware service provisioning efficiently. The proposed algorithm is evaluated with extensive simulations and the results confirm its effectiveness.
Autors: Jing Zhu;Bin Zhao;Zuqing Zhu;
Appeared in: Journal of Lightwave Technology
Publication date: May 2017, volume: 35, issue:10, pages: 1785 - 1796
Publisher: IEEE
 
» LiDAR Data Classification Using Extinction Profiles and a Composite Kernel Support Vector Machine
Abstract:
This letter proposes a novel framework for the classification of light detection and ranging (LiDAR)-derived features. In this context, several features are extracted directly from the LiDAR point cloud data using aggregated local point neighborhoods, including laser echo ratio, variance of point elevation, plane fitting residuals, and echo intensity. Additionally, the LiDAR digital surface model (DSM) is input to our classification. Thus, both the LiDAR raster DSM and also rich geometric and also backscatter 3-D point cloud information aggregated to images are considered in our workflow. These extracted features are characterized as base images to be fed to extinction profiles to model spatial and contextual information. Then, a composite kernel support vector machine is investigated to efficiently integrate the elevation and spatial information suitable for the LiDAR data. Results indicate that the proposed method can obtain high classification accuracy using LiDAR data alone (e.g., more than 86% overall accuracy on the benchmark Houston LiDAR data using the standard set of training and test samples on all 15 classes) in a short CPU processing time.
Autors: Pedram Ghamisi;Bernhard Höfle;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: May 2017, volume: 14, issue:5, pages: 659 - 663
Publisher: IEEE
 
» Light-Emitting Illumination and Field Emission Device of Potassium Hydroxide-Doped Electrochemically Reduced Graphene Oxide
Abstract:
This paper presents a parallel plate-type field emission device of potassium hydroxide-doped electrochemically reduced graphene oxide (GO) manufactured using highly oriented pyrolytic graphite through electrochemical exfoliation. The material properties of the GO were tested through Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The optimal electron emission characteristics of the device were as follows: turn-on field = 2.03 V/, field emission current , and field emission enhancement factor = 8377. At an emission peak wavelength of 563.7 nm, the optimal device had a light flux of 4.21 lumens and an illumination of 140.3 lux. These properties can be utilized in various optoelectronic devices, such as nanoelectronics devices, sensors, electrochemical systems, and energy storage devices.
Autors: Ching-Tsang Chang;Yi-Tsung Chang;Yun-Jhong Chih;Yu-Hao Lee;Chun-Hu Chen;Lung-Chien Chen;Jau-Je Wu;
Appeared in: IEEE Transactions on Electron Devices
Publication date: May 2017, volume: 64, issue:5, pages: 2251 - 2256
Publisher: IEEE
 
» Lighting Matters in Industrial Environments: A Framework Linking Workplace Safety to Lighting Quality Metrics
Abstract:
Lighting affects human performance and, therefore, safety in industrial environments. Recent developments in light-emitting diode (LED) lighting technology offer an opportunity for a scientific evaluation of the quality of light in industrial spaces. For this article, the possibility of reducing the risk of key causes of occupational hazards through the effective application of lighting was evaluated. Vision science research was reviewed to identify mechanisms that could improve object detection, supra threshold visual performance, and response time. Metrics to quantify these mechanisms-i.e., small target visibility (STV), relative visual performance (RVP), mesopic luminance, and luminaire system application efficacy (LSAE)-were reviewed and applied in the context of industrial lighting installations. The results indicated the potential to harness new lighting technology to enhance visual task performance and thereby improve safety and productivity. Lighting is also related to the fatigue of industrial workers. It could influence fatigue by degrading the sleep quality of night-shift workers, causing visual discomfort and creating a negative perception of the environment. A review of research, simulations, and calculations led the authors to develop a framework that links occupational injury incidents to lighting quality metrics for industrial environments. This framework needs to be validated using field studies that are designed based on this research. In this period of technological transition, facility managers can use this study to benchmark lighting technologies and installations for safety. This article presents value propositions that a versatile and controllable source such as LEDs could offer to industries.
Autors: Asiri Jayawardena;David Duffy;Joseph M. Manahan;
Appeared in: IEEE Industry Applications Magazine
Publication date: May 2017, volume: 23, issue:3, pages: 54 - 63
Publisher: IEEE
 
» Limited-Feedback Low-Encoding Complexity Precoder Design for Downlink of FDD Multi-User Massive MIMO Systems
Abstract:
We investigate a limited feedback precoder based on symbol pairwise error probability (PEP) for a block-faded downlink multiple-input multiple-output (MIMO) channel. In the considered system, single-antenna users feedback quantized channel state information to the -antenna transmitter using bits per-transmit-antenna per user. We analytically show that for , and , both symbol PEP and achievable rate of each of the downlink users almost surely converge to the symbol PEP and achievable rate of parallel additive white Gaussian noise (AWGN) channels, respectively. We show that the encoding complexity of the precoder is . We also show that if channel coefficients estimated by the user are corrupted by AWGN noise, the symbol PEP and achievable rate of each user almost surely converge to the symbol PEP and achievable rate in a scaled AWGN channel with and . For correlated channels, we derive a co- dition, which enables the proposed precoder almost surely to cancel multi-user interference for large values. Finally, we numerically compare the bit error rate, encoding complexity, and per-user achievable rate of the proposed scheme with the existing designs.
Autors: Biswajit Dutta;Rohit Budhiraja;David R. Koilpillai;
Appeared in: IEEE Transactions on Communications
Publication date: May 2017, volume: 65, issue:5, pages: 1956 - 1971
Publisher: IEEE
 
» Line-of-Sight Millimeter-Wave Communications Using Orbital Angular Momentum Multiplexing Combined With Conventional Spatial Multiplexing
Abstract:
Line-of-sight wireless communications can benefit from the simultaneous transmission of multiple independent data streams through the same medium in order to increase system capacity. A common approach is to use conventional spatial multiplexing with spatially separated transmitter/receiver antennae, for which inter-channel crosstalk is reduced by employing multiple-input-multiple-output (MIMO) signal processing at the receivers. Another fairly recent approach to transmitting multiple data streams is to use orbital-angular-momentum (OAM) multiplexing, which employs the orthogonality among OAM beams to minimize inter-channel crosstalk and enable efficient (de)multiplexing. In this paper, we explore the potential of utilizing both of these multiplexing techniques to provide system design flexibility and performance enhancement. We demonstrate a 16 Gbit/s millimeter-wave link using OAM multiplexing combined with conventional spatial multiplexing over a short link distance of 1.8 meters (shorter than Rayleigh distance). Specifically, we implement a spatial multiplexing system with a antenna aperture architecture, in which each transmitter aperture contains two multiplexed 4 Gbit/s data-carrying OAM beams. A MIMO-based signal processing is used at the receiver to mitigate channel interference. Our experimental results show performance improvements for all channels after MIMO processing, with bit-error rates of each channel below the forward error correction limit of . We also simulate the capacity for both the MIMO system and the MIMO with OAM multiplexing. Our work indicates that OAM multiplexing and conventional spatial multipl- xing can be simultaneously utilized to provide design flexibility. The combination of these two approaches can potentially enhance system capacity given a fixed aperture area of the transmitter/receiver (when the link distance is within a few Rayleigh distances).
Autors: Yongxiong Ren;Long Li;Guodong Xie;Yan Yan;Yinwen Cao;Hao Huang;Nisar Ahmed;Zhe Zhao;Peicheng Liao;Chongfu Zhang;Giuseppe Caire;Andreas F. Molisch;Moshe Tur;Alan E. Willner;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: May 2017, volume: 16, issue:5, pages: 3151 - 3161
Publisher: IEEE
 
» Linear Diversity Combining on Correlated and Unequal Power Nakagami-0.5 Fading Channels
Abstract:
Closed-form or analytical solutions for the outage probability and average probability of symbol error are derived for correlated (and independent), unequal power dual branch Nakagami-0.5 linear diversity combining schemes. A novel analytical solution for the probability density function of the sum of two correlated, dissimilar Nakagami-0.5 random variables is derived.
Autors: N. C. Beaulieu;Yixing Zhang;
Appeared in: IEEE Communications Letters
Publication date: May 2017, volume: 21, issue:5, pages: 1003 - 1006
Publisher: IEEE
 
» Link Regimes Analysis for Partial Decode-Forward Two-Way Relay Transmission
Abstract:
We propose a composite decode-forward (DF) scheme for the two-way relay channel in the full-duplex mode by combining coherent, independent, and partial relaying strategies. The relay partially decodes each user’s information in each block and forwards this information coherently with the source user to the destination user in the next block as in block Markov coding. In addition, the relay independently broadcasts a binning index of both users’ decoded information parts in the next block as in independent network coding. Each technique has a different impact on the relay power usage and the rate region. We further consider the independent and partial DF scheme for its more practical channel state information requirements, and derive in closed-form link regimes when this scheme achieves a strictly larger rate region than just time sharing between its constituent techniques, direct transmission, and independent DF relaying, and when it reduces to a simpler scheme. The analytical approach is based on maximizing the weighted composite DF sum rate and comparing with the outermost time-sharing line connecting corner points of rate regions of the constituent techniques. Numerical results demonstrate significant rate gains by performing link adaptation of the composite scheme based on the identified link regimes.
Autors: Ahmad Abu Al Haija;Peng Zhong;Mai Vu;
Appeared in: IEEE Transactions on Communications
Publication date: May 2017, volume: 65, issue:5, pages: 1925 - 1939
Publisher: IEEE
 
» Lithium-Ion Battery Charge Equalization Algorithm for Electric Vehicle Applications
Abstract:
The lithium-ion batteries are commonly used in electric vehicle (EV) applications due to their better performances as compared with other batteries. However, lithium-ion battery has some drawbacks such as the overcharged cell which has a risk of explosion, the undercharged cell eventually reduces the life cycle of the battery, and unbalanced charge in series battery gradually reduces overall charge capacity. This paper presents a battery charge equalization algorithm for lithium-ion battery in EV applications to enhance the battery's performance, life cycle, and safety. The algorithm is implemented in series-connected battery cells of 15.5 Ah and 3.7 V nominal each using a battery monitoring integrated circuit for monitoring and equalization of an 8-cell battery pack using a bidirectional flyback dc–dc converter as the channel for charging and discharging of the battery cell. The obtained results show that the developed charge equalization controller algorithm performs well in equalizing both undercharged and overcharged cells, and equalizes the cell within the safety operation range of 3.81 V. To validate the charge equalizer performance, the proposed algorithm outperforms with other studies in terms of balancing, equalization speed, low power loss, and efficiency. Thus, the proposed battery charge equalization algorithm proves an effective and automated system to modularize the battery charge that improves the safety and life cycle of battery.
Autors: Mohammad Abdul Hannan;Md. Murshadul Hoque;Seow Eng Peng;M. Nasir Uddin;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 2541 - 2549
Publisher: IEEE
 
» Live Prefetching for Mobile Computation Offloading
Abstract:
Mobile computation offloading refers to techniques for offloading computation intensive tasks from mobile devices to the cloud so as to lengthen the formers’ battery lives and enrich their features. The conventional designs fetch (transfer) user-specific data from mobiles to the cloud prior to computing, called offline prefetching. However, this approach can potentially result in excessive fetching of large volumes of data and cause heavy loads on radio-access networks. To solve this problem, the novel technique of live prefetching, which seamlessly integrates the task-level computation prediction and prefetching within the cloud-computing process of a large program with numerous tasks, is proposed in this paper. The technique avoids excessive fetching but retains the feature of leveraging prediction to reduce the program runtime and mobile transmission energy. By modeling the tasks in an offloaded program as a stochastic sequence, stochastic optimization is applied to design fetching policies to minimize mobile energy consumption under a deadline constraint. The policies enable real-time control of the prefetched-data sizes of candidates for future tasks. For slow fading, the optimal policy is derived and shown to have a threshold-based structure, selecting candidate tasks for prefetching and controlling their prefetched data based on their likelihoods. The result is extended to design close-to-optimal prefetching policies to fast fading channels. Compared with fetching without prediction, live prefetching is shown theoretically to always achieve reduction on mobile energy consumption.
Autors: Seung-Woo Ko;Kaibin Huang;Seong-Lyun Kim;Hyukjin Chae;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: May 2017, volume: 16, issue:5, pages: 3057 - 3071
Publisher: IEEE
 
» Load Optimization With User Association in Cooperative and Load-Coupled LTE Networks
Abstract:
We extend the problem of optimizing user association for load balancing in cellular networks along 2-dimensions. First, we consider joint transmission, which is one of the coordinated multipoint techniques with which a user may be simultaneously served by multiple base stations. Second, we account for, mathematically, the coupling relation between the base stations’ load levels that are dependent on each other due to inter-cell interference. We formulate two optimization problems, sum load minimization (MinSumL) and maximum load minimization (MinMaxL). We prove that both MinSumL and MinMaxL are -hard. We propose a mixed integer linear programming based scheme by means of linearization. This approach also leads to a bounding scheme for performance benchmarking. Then, we derive a set of partial optimality conditions. Fulfillment of the conditions will guarantee performance improvement for both MinSumL and MinMaxL. A solution algorithm is then derived based on the conditions. Simulation results are provided to demonstrate the effectiveness of the approaches.
Autors: Lei You;Di Yuan;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: May 2017, volume: 16, issue:5, pages: 3218 - 3231
Publisher: IEEE
 
» Local Controllability of the Two-Link Magneto-Elastic Micro-Swimmer
Abstract:
A recent promising technique for robotic micro-swimmers is to endow them with a magnetization and apply an external magnetic field to provoke their deformation. In this technical note, we consider a simple planar micro-swimmer model made of two magnetized segments connected by an elastic joint, controlled via a magnetic field. After recalling the analytical model, we establish a local controllability result around the straight position of the swimmer.
Autors: Laetitia Giraldi;Jean-Baptiste Pomet;
Appeared in: IEEE Transactions on Automatic Control
Publication date: May 2017, volume: 62, issue:5, pages: 2512 - 2518
Publisher: IEEE
 
» Local Defect Density in Polycrystalline High-k Dielectrics: CAFM-Based Evaluation Methodology and Impact on MOSFET Variability
Abstract:
A methodology to determine with nanometer resolution the defect density in polycrystalline HfO2 layers has been developed. This methodology is based on experimental data measured with conductive atomic force microscopy and the obtained results have been validated using Kelvin prove force microscopy measurements. The local defect density () and thickness () of the gate dielectric have been included into a device simulator to evaluate their impact on the curves of MOSFETs.
Autors: C. Couso;M. Porti;J. Martin-Martinez;A. J. Garcia-Loureiro;N. Seoane;M. Nafria;
Appeared in: IEEE Electron Device Letters
Publication date: May 2017, volume: 38, issue:5, pages: 637 - 640
Publisher: IEEE
 
» Localization of Radial Deformation and Its Extent in Power Transformer HV Winding Using Stationary UWB Antennas
Abstract:
In this paper, three monitoring stages of detection, localization, and extent determination of radial deformation in power transformer winding using stationary ultra-wideband antennas, are investigated. For this purpose, two types of radial deformation are implemented on the actual transformer high-voltage winding. The first type is a modeled bulgy mechanical deformation, which its extent and reversibility may be changed and it can occur in different positions. The second type is an actual radial deformation applied to the winding. Hyperboloid method and 2-D locus of the winding are adopted in the localization stage. To perform a precise analysis of the received signals, matched filter technique is employed. The extent of the deformation is also determined by magnitude Euclidean distance index. The experimental results prove the effectiveness of the proposed method.
Autors: H. Rahbarimagham;S. Esmaeili;G. B. Gharehpetian;
Appeared in: IEEE Sensors Journal
Publication date: May 2017, volume: 17, issue:10, pages: 3184 - 3192
Publisher: IEEE
 
» Localizing Microaneurysms in Fundus Images Through Singular Spectrum Analysis
Abstract:
Goal: Reliable recognition of microaneurysms (MAs) is an essential task when developing an automated analysis system for diabetic retinopathy (DR) detection. In this study, we propose an integrated approach for automated MA detection with high accuracy. Methods: Candidate objects are first located by applying a dark object filtering process. Their cross-section profiles along multiple directions are processed through singular spectrum analysis. The correlation coefficient between each processed profile and a typical MA profile is measured and used as a scale factor to adjust the shape of the candidate profile. This is to increase the difference in their profiles between true MAs and other non-MA candidates. A set of statistical features of those profiles is then extracted for a K-nearest neighbor classifier. Results: Experiments show that by applying this process, MAs can be separated well from the retinal background, the most common interfering objects and artifacts. Conclusion: The results have demonstrated the robustness of the approach when testing on large scale datasets with clinically acceptable sensitivity and specificity. Significance: The approach proposed in the evaluated system has great potential when used in an automated DR screening tool or for large scale eye epidemiology studies.
Autors: Su Wang;Hongying Lilian Tang;Lutfiah Ismail Al turk;Yin Hu;Saeid Sanei;George Michael Saleh;Tunde Peto;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: May 2017, volume: 64, issue:5, pages: 990 - 1002
Publisher: IEEE
 
» Logic-Form-Equation-Based Active Capacitor Voltage Balancing Control Technique for Stacked Multicell Converters
Abstract:
This paper proposes a novel active capacitor voltage balancing technique for stacked multicell (SM) converters. The proposed active capacitor voltage balancing control method detects the direction of the load current and measures the voltage of flying capacitors (FCs) to generate a proper switching state in order to form the required output voltage level and regulate the FC voltages at their desired reference levels. The proposed active capacitor voltage balancing control technique can modulate the output voltage through any of the pulse-width-modulation (PWM) techniques such as the phase-shifted carrier PWM or the level-shifted-carrier PWM. The foremost advantage of the proposed active control technique is that it does not demand any complex computations because it is not based on the optimization of the FC voltage-deviation cost functions. A thorough set of simulation results and experimental measurements for the five-level and seven-level SM converters are provided to validate the proposed active capacitor voltage balancing control method.
Autors: Arash Khoshkbar Sadigh;Vahid Dargahi;Keith A. Corzine;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: May 2017, volume: 64, issue:5, pages: 3456 - 3466
Publisher: IEEE
 
» Logical Correlation-Based Sleep Scheduling for WSNs in Ambient-Assisted Homes
Abstract:
This paper proposes a logical correlation-based sleep scheduling mechanism (LCSSM) to implement energy-efficient wireless sensor networks (WSNs) in ambient-assisted homes (AAHs). LCSSM analyzes sensory data generated by different human behaviors to detect the logical correlations between sensor nodes in an AAH. By utilizing the particular logical correlations of an AAH to predict its usage status, LCSSM deactivates sensor nodes accordingly to save energy when they are not expected to sense any valuable event. Evaluation results based on real life-logs have validated that LCSSM not only reduces the energy consumption of WSNs significantly, but also retains their quality of sensing successfully, e.g., with a moderate assumption on the duty cycling ratio and hardware configuration of sensor nodes, LCSSM successfully senses 98.7% valuable events with an average of 37.0% usual energy consumption, and extends the life time of WSNs by 63.4%.
Autors: Wei Liu;Yozo Shoji;Ryoichi Shinkuma;
Appeared in: IEEE Sensors Journal
Publication date: May 2017, volume: 17, issue:10, pages: 3207 - 3218
Publisher: IEEE
 
» Long-Term Scatterometer Wind Climate Data Records
Abstract:
The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Ocean and Sea Ice Satellite Application Facility (OSI SAF) produces near-real-time scatterometer ocean vector winds since almost 20 years already. Data from the European remote sensing satellites (ERS-1 and ERS-2 scatterometer), QuikSCAT (SeaWinds), Metop (ASCAT), Oceansat 2 (OSCAT), and RapidScat on the International Space Station have been, or are being, produced. The OSI SAF scatterometer products, produced at the Royal Netherlands Meteorological Institute, provide superior comparison to both buoy and numerical weather prediction (NWP) datasets. Moreover, the wind processing software is publicly available through the EUMETSAT NWP SAF. An increasing amount of users employs scatterometer wind data for climate studies. However, the wind retrieval algorithms have been continuously improved over the years and the currently existing archives of near-real-time data are not always suitable to fulfill the need for homogeneous datasets spanning a longer period of time. Currently, only few validated vector wind climate datasets are available. Therefore, the OSI SAF is reprocessing several offline datasets. This paper is focusing on two climate data records from SeaWinds and ASCAT winds, which together span the period from 1999 to 2014. The data are compared to the NWP model and buoy winds. The stability of the wind characteristics is assessed and an attempt is made to attribute temporal changes to climatological and NWP model changes over time.
Autors: Anton Verhoef;Jur Vogelzang;Jeroen Verspeek;Ad Stoffelen;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: May 2017, volume: 10, issue:5, pages: 2186 - 2194
Publisher: IEEE
 
» Longitudinal Electro-Optic Probe for the Transient Analysis of the Radial Field Surrounding a Three-Phase Cable
Abstract:
In this paper, we present the potentialities of the electro-optic technique for the radial electric field transient analysis of a three-phase power cable. A longitudinal electro-optic probe performing real time characterization of the field surrounding the cable has been developed. The measurement gives the transient evolution of the radial component of the field. The analysis provides information on amplitude, position, and phase of the conductors in the multicore cable. Theoretical analysis, simulations, and experimental measurements are in agreement and demonstrate the contactless voltage diagnostic of multicore cables.
Autors: Laurane Gillette;Gwenaël Gaborit;Jean Dahdah;Anne Grau;Valérie Murin;Lionel Duvillaret;
Appeared in: IEEE Sensors Journal
Publication date: May 2017, volume: 17, issue:9, pages: 2807 - 2813
Publisher: IEEE
 
» Longitudinal Privacy Management in Social Media: The Need for Better Controls
Abstract:
This large-scale measurement study of Twitter focuses on understanding how users control the longitudinal exposure of their publicly shared social data -- that is, their tweets -- and the limitations of currently used control mechanisms. The study finds that, while Twitter users widely employ longitudinal exposure control mechanisms, they face two fundamental problems. First, even when users delete their data or account, the current mechanisms leave significant traces of residual activity. Second, these mechanisms single out withdrawn tweets or accounts, attracting undesirable attention to them. To address both problems, an inactivity-based withdrawal scheme for improved longitudinal exposure control is explored.
Autors: Mainack Mondal;Johnnatan Messias;Saptarshi Ghosh;Krishna P. Gummadi;Aniket Kate;
Appeared in: IEEE Internet Computing
Publication date: May 2017, volume: 21, issue:3, pages: 48 - 55
Publisher: IEEE
 
» Loop Shaping of a Wide-Area Damping Controller Using HVDC
Abstract:
Insufficiently damped inter-area oscillatory behavior in large power systems may be mitigated by the application of a feedback control system. Thorough investigation of the resonant features unique to the western North American power system suggests that the modulation of active power using high-voltage dc has great impact on retaining system stability when actuation is provided by the geographically expansive pacific dc intertie transmission line. The controller is limited in bandwidth by the influences of time delay, sensor and actuator dynamics, and specific plant characteristics. While proportional feedback of the scaled difference of two disparate bus frequencies has shown to be a valid method for controlling this particular system in previous work, the authors submit that a shaped loop transmission function provides performance and noise response improvement with guaranteed stability in saturation. Results of simulations using a high fidelity model of the system show the efficacy of the approach.
Autors: Dakota Roberson;John F. O’Brien;
Appeared in: IEEE Transactions on Power Systems
Publication date: May 2017, volume: 32, issue:3, pages: 2354 - 2361
Publisher: IEEE
 
» Low-Complexity and Low-Feedback-Rate Channel Allocation in CA MIMO Systems With Heterogeneous Channel Feedback
Abstract:
In this paper, we propose a low complexity and low-feedback-rate channel allocation for carrier aggregation (CA) MIMO systems as an application to heterogeneous networks (HetNets) with multiple component carriers (CCs) and users. The proposed channel allocation technique relies on the heterogeneous channel feedback concept due to the heterogeneous channel statistics of the different CCs. We apply the heterogeneous channel feedback, where the channel feedback granularity is provided using best- selected feedback strategy. The precoding matrix indicator (PMI) and rank indicator (RI) are designed with a low complexity so that the PMI/RI reports are calculated more efficiently per CC and user. This approach reduces the complexity significantly in a multiuser and multichannel scenario. Next, we deal with the low-feedback rate and thus devise a channel allocation problem. The problem on one hand provides the minimization of the feedback overhead and, on the other hand, it guarantees the quality-of-service request of each user for a specific target throughput. The problem is considered as a channel assignment problem; thus, the Hungarian method is first used. Next, a low complexity solution is devised using the stable matching algorithm. A complexity analysis and evaluation among the original and the proposed approach for the low-complexity and the low-feedback-rate channel allocation is carried out. This comparison reveals the benefits of the proposed solution for CA MIMO system in HetNets. The proposed approach can be considered as a proposal to the future massive CA, i.e., up to 32 CCs.
Autors: Christos Tsinos;Apostolos Galanopoulos;Fotis Foukalas;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 4396 - 4409
Publisher: IEEE
 
» Low-Complexity Image and Video Coding Based on an Approximate Discrete Tchebichef Transform
Abstract:
The usage of linear transformations has great relevance for data decorrelation applications, like image and video compression. In that sense, the discrete Tchebichef transform (DTT) possesses useful coding and decorrelation properties. The DTT transform kernel does not depend on the input data and fast algorithms can be developed to real-time applications. However, the DTT fast algorithm presented in literature possess high computational complexity. In this paper, we introduce a new low-complexity approximation for the DTT. The fast algorithm of the proposed transform is multiplication free and requires a reduced number of additions and bit-shifting operations. Image and video compression simulations in popular standards show good performance of the proposed transform. Regarding hardware resource consumption for FPGA shows a 43.1% reduction in configurable logic blocks and ASIC place and route realization shows a 57.7% reduction in the area-time figure compared with the 2D version of the exact DTT.
Autors: Paulo A. M. Oliveira;Renato J. Cintra;Fábio M. Bayer;Sunera Kulasekera;Arjuna Madanayake;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: May 2017, volume: 27, issue:5, pages: 1066 - 1076
Publisher: IEEE
 
» Low-Complexity OSIC Equalization for OFDM-Based Vehicular Communications
Abstract:
Vehicular communication systems are usually equipped with orthogonal frequency division multiplexing (OFDM) transceivers that operate on rapidly changing radio propagation environments, which results in high Doppler and delay spreads. More specifically, in these environments, the experienced channels are doubly selective and introduce severe intercarrier interference (ICI) at the receiver. An effective ICI mitigation technique is desired as a constituent part of an ordered successive interference cancellation (OSIC) architecture, which turns out to be computationally efficient, since it may require the solution of linear systems with multiple right-hand sides. To decrease the complexity, several techniques suggest mitigating the ICI by considering only a small number of adjacent subcarriers. However, this approximation introduces an error floor, which may result in unacceptable bit error rates (BER) at high signal-to-noise ratio regimes. In this paper, we propose a new OSIC equalization technique based on an iterative Galerkin projection-based algorithm that reduces the computational cost without sacrificing the performance gains of the OSIC architecture. Furthermore, we suggest a new serial/parallel cancellation architecture that extends the OSIC and has the potential to completely cancel the experienced ICI introduced in high-mobility scenarios. Extensive Monte Carlo experiments have been carried out to validate the accuracy of our framework, revealing intriguing tradeoffs between achieved BER and complexity, and highlighting the importance of designing low-complexity OSIC schemes for OFDM systems operating over double selective channels.
Autors: Evangelos Vlachos;Aris S. Lalos;Kostas Berberidis;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 3765 - 3776
Publisher: IEEE
 

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