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

» 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 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
 
» 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
 
» Low-Cost 3-D Flow Estimation of Blood With Clutter
Abstract:
Volumetric flow rate estimation is an important ultrasound medical imaging modality that is used for diagnosing cardiovascular diseases. Flow rates are obtained by integrating velocity estimates over a cross-sectional plane. Speckle tracking is a promising approach that overcomes the angle dependency of traditional Doppler methods, but suffers from poor lateral resolution. Recent work improves lateral velocity estimation accuracy by reconstructing a synthetic lateral phase (SLP) signal. However, the estimation accuracy of such approaches is compromised by the presence of clutter. Eigen-based clutter filtering has been shown to be effective in removing the clutter signal; but it is computationally expensive, precluding its use at high volume rates. In this paper, we propose low-complexity schemes for both velocity estimation and clutter filtering. We use a two-tiered motion estimation scheme to combine the low complexity sum-of-absolute-difference and SLP methods to achieve subpixel lateral accuracy. We reduce the complexity of eigen-based clutter filtering by processing in subgroups and replacing singular value decomposition with less compute-intensive power iteration and subspace iteration methods. Finally, to improve flow rate estimation accuracy, we use kernel power weighting when integrating the velocity estimates. We evaluate our method for fast- and slow-moving clutter for beam-to-flow angles of 90° and 60° using Field II simulations, demonstrating high estimation accuracy across scenarios. For instance, for a beam-to-flow angle of 90° and fast-moving clutter, our estimation method provides a bias of −8.8% and standard deviation of 3.1% relative to the actual flow rate.
Autors: Siyuan Wei;Ming Yang;Jian Zhou;Richard Sampson;Oliver D. Kripfgans;J. Brian Fowlkes;Thomas F. Wenisch;Chaitali Chakrabarti;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: May 2017, volume: 64, issue:5, pages: 772 - 784
Publisher: IEEE
 
» Low-Cost Architecture of Modified Daubechies Lifting Wavelets Using Integer Polynomial Mapping
Abstract:
This brief proposes a modified version of the popular lifting algorithm of Daubechies-4 (D4) and Daubechies-6 (D6) wavelets and its efficient implementation using integer polynomial mapping (IPM). At first, an improved polyphase matrix for D4 is presented that eliminates one filter coefficient completely without losing any accuracy. Then, IPM is applied to encode the remaining irrational coefficients. As a result, computation error due to irrational numbers in the conventional method is significantly reduced, resulting in better image reconstruction. For D6, a two-level optimization scheme combined with the resource sharing of coefficients is applied that results in simplified hardware architecture with much fewer resources.
Autors: Md. Mehedi Hasan;Khan A. Wahid;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: May 2017, volume: 64, issue:5, pages: 585 - 589
Publisher: IEEE
 
» Low-cost CDC ROADM architecture based on stacked wavelength selective switches
Abstract:
A highly flexible, stacked, switch module is proposed, wherein multiple independent 1 × N wavelength selective switches (WSSs) can be realized on a single 4k liquid crystal on silicon device. The stacked WSS module can be configured in different ways for application at either the transit side or the add/drop side of a colorless, directionless, and contentionless (CDC) reconfigurable optical add/drop multiplexer (ROADM). TwoROADMarchitectures are proposed based on the stacked WSS modules. Their costs are analyzed for both a 4-deg network node and a larger 8-deg node. The first proposed ROADM architecture with full CDC features is shown to realize a cost reduction of at least 35% in these two test network nodes, when compared with the conventional CDC ROADMarchitecture based on the standalone WSSs and multicasting switches (MCSs). The second ROADM architecture proposed has a small probability of wavelength contention, which could be prevented by a local wavelength assignment algorithm. According to our cost estimation, we are able to aggressively reduce the number of components at the add/drop side and make an overall cost reduction of >70% and >80% in the 4- and 8-deg network nodes, respectively.
Autors: Haining Yang;Brian Robertson;Peter Wilkinson;Daping Chu;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: May 2017, volume: 9, issue:5, pages: 375 - 384
Publisher: IEEE
 
» Low-Cost, Direct-Fed Slot Antenna Built in Metal Cover of Notebook Computer for 2.4-/5.2-/5.8-GHz WLAN Operation
Abstract:
The slot antenna has been utilized for some recent notebook computers on the market. The FR4 substrates are usually required to print the metal patterns for coupled-feeding the 2.4 GHz (2400–2484 MHz) slot and also for contributing the 5.2 GHz (5150–5350 MHz) and 5.8 GHz (5725–5825 MHz) bands. This communication presents a simple, direct-fed slot antenna with a low profile of 7 mm to the top edge of the metal cover for 2.4-/5.2-/5.8-GHz WLAN operation. The antenna design did not require any substrate and can be implemented directly in the metal cover of a notebook computer at low cost. The design comprised two parallel-connected, 0.5-wavelength-slot portions, formed in a linear structure of length 79 mm and constant width 2 mm, and fed by a common antenna feed port using a mini-coaxial cable. The larger slot generated a 0.5-wavelength resonant mode in the 2.4-GHz band and a 1-wavelength mode for 5.2-GHz operation. The smaller slot operated in a 0.5-wavelength resonant mode, which covered the 5.8-GHz band. With a matching inductor properly set in the slot, good input impedance over the 2.4-, 5.2-, and 5.8-GHz bands can be attained.
Autors: Cheng-Tse Lee;Saou-Wen Su;Shu-Chuan Chen;Chen-Shuo Fu;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: May 2017, volume: 65, issue:5, pages: 2677 - 2682
Publisher: IEEE
 
» Low-Power Energy Generation Systems for Two-Phase PM Machine With Reduced-Switch-Count Controlled Switches
Abstract:
This paper investigates two power generation systems that utilize a rectifier with small number of controlled switches associated to a two-phase permanent magnet synchronous machine. The proposed topologies have as a main purpose converting wind energy into electrical energy for low-power applications, giving them large potential to be employed in urban and rural areas. Each configuration is commanded by only two controlled switches and has natural protection against short circuit on the dc link. Compared with two three-phase generation systems that use a reduced number of controlled switches, the proposed topologies permit obtaining sinusoidal machine currents, with low harmonic distortion, using a smaller number of controlled switches. At last, to investigate the proposed system and control strategy, simulation and experimental results are presented.
Autors: Filipe Antônio da Costa Bahia;Cursino Brandão Jacobina;Nady Rocha;Italo Roger Ferreira Moreno Pinheiro da Silva;Fabiano Salvadori;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 2320 - 2328
Publisher: IEEE
 
» Low-Rank and Adaptive Sparse Signal (LASSI) Models for Highly Accelerated Dynamic Imaging
Abstract:
Sparsity-based approaches have been popular in many applications in image processing and imaging. Compressed sensing exploits the sparsity of images in a transform domain or dictionary to improve image recovery fromundersampledmeasurements. In the context of inverse problems in dynamic imaging, recent research has demonstrated the promise of sparsity and low-rank techniques. For example, the patches of the underlying data are modeled as sparse in an adaptive dictionary domain, and the resulting image and dictionary estimation from undersampled measurements is called dictionary-blind compressed sensing, or the dynamic image sequence is modeled as a sum of low-rank and sparse (in some transform domain) components (L+S model) that are estimated from limited measurements. In this work, we investigate a data-adaptive extension of the L+S model, dubbed LASSI, where the temporal image sequence is decomposed into a low-rank component and a component whose spatiotemporal (3D) patches are sparse in some adaptive dictionary domain. We investigate various formulations and efficient methods for jointly estimating the underlying dynamic signal components and the spatiotemporal dictionary from limited measurements. We also obtain efficient sparsity penalized dictionary-blind compressed sensing methods as special cases of our LASSI approaches. Our numerical experiments demonstrate the promising performance of LASSI schemes for dynamicmagnetic resonance image reconstruction from limited k-t space data compared to recent methods such as k-t SLR and L+S, and compared to the proposed dictionary-blind compressed sensing method.
Autors: Saiprasad Ravishankar;Brian E. Moore;Raj Rao Nadakuditi;Jeffrey A. Fessler;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: May 2017, volume: 36, issue:5, pages: 1116 - 1128
Publisher: IEEE
 
» Low-Rank Spatial Channel Estimation for Millimeter Wave Cellular Systems
Abstract:
The tremendous bandwidth available in the millimeter wave frequencies above 10 GHz have made these bands an attractive candidate for next-generation cellular systems. However, reliable communication at these frequencies depends critically on beamforming with very high-dimensional antenna arrays. Estimating the channel sufficiently accurately to perform beamforming can be challenging due to both low coherence time and a large number of antennas. Also, the measurements used for channel estimation may need to be made with analog beamforming, where the receiver can “look” in only one direction at a time. This paper presents a novel method for estimation of the receive-side spatial covariance matrix of a channel from a sequence of power measurements made in different angular directions. It is shown that maximum likelihood estimation of the covariance matrix reduces to a non-negative matrix completion problem. We show that the non-negative nature of the covariance matrix reduces the number of measurements required when the matrix is low-rank. The fast iterative methods are presented to solve the problem. Simulations are presented for both single-path and multi-path channels using models derived from real measurements in New York City at 28 GHz.
Autors: Parisa A. Eliasi;Sundeep Rangan;Theodore S. Rappaport;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: May 2017, volume: 16, issue:5, pages: 2748 - 2759
Publisher: IEEE
 
» Low-Temperature, Solution-Processed, 3-D Complementary Organic FETs on Flexible Substrate
Abstract:
Vertical stacking of thin-film transistors is an effective way to reduce the footprint of a device, thus increases transistor density in complex flexible electronic applications without reducing the feature size and resolution of the patterning tools. In this paper, we report a 3-D complementary organic FET fabricated on a plastic substrate by stacking a bottom-gate top-contact p-type transistor on a top-gate bottom-contact n-type transistor with a gate shared between the two. We used high-performance polymer semiconductors, poly [(E)-2, 7-bis (2 decyltetradecyl) 4 methyl 9 (5 (2 (5 methylthiophen 2 yl) vinyl) thiophen 2 yl) benzo [lmn] [3, 8] phenanthroline-1, 3, 6, 8 (2H, 7H)-tetraone] for n-type devices and poly [2, 5-bis (7-decylnonadecyl) pyrrolo [3, 4-c] pyrrole-1, 4 (2H, 5H)-dione-(E) 1,2 bis (5 (thiophen 2 yl) selenophen 2 yl) ethene] for p-type devices to fabricate the vertically stacked organic transistors along with a Cytop and cross-linked poly (4-vinylphenol) bilayer and Poly (Methyl Methacrylate) gate dielectric. A 3-D flexible complementary organic inverter exhibits a maximum static voltage gain of V/V and high noise immunity of up to 60% of /2. The 3-D transistors show hysteresis-free – characteristics despite of low-temperature processes. Moreover, we discuss the influence of cross-linker concentration and the processing temperature of the PVP dielectric film on the degree of hysteresis in – characteristics.
Autors: Sujeong Kyung;Jimin Kwon;Yun-Hi Kim;Sungjune Jung;
Appeared in: IEEE Transactions on Electron Devices
Publication date: May 2017, volume: 64, issue:5, pages: 1955 - 1959
Publisher: IEEE
 
» LTCC-Integrated $H$ -Plane Bends for THz Antenna-in-Package Solution
Abstract:
We present a compact terahertz antenna-in-package solution using a substrate integrated waveguide (SIW), which connects an integrated circuit (IC) to an SIW antenna. To suppress the leakage of electromagnetic waves due to bending a low-temperature cofired ceramic (LTCC) substrate, an H-plane bend SIW in the LTCC was investigated using the E-plane split-block technology. We introduced an IC with a CPW-to-waveguide transition into the hollow SIW. The insertion loss, estimated by measuring a back-to-back transition with the H-plane-bend SIW, is 1.6 dB at 300 GHz, and 49-GHz bandwidth with less than 10-dB return loss is achieved.
Autors: Takuro Tajima;Ho-Jin Song;Hideaki Matsuzaki;Makoto Yaita;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: May 2017, volume: 27, issue:5, pages: 440 - 442
Publisher: IEEE
 
» Magnet Temperature Effects on the Useful Properties of Variable Flux PM Synchronous Machines and a Mitigating Method for Magnetization Changes
Abstract:
Variable flux permanent magnet synchronous machines (VF-PMSMs) use permanent magnet magnetization as an additional degree-of-freedom to reduce losses based on operating conditions (e.g., at medium to high speeds, losses are reduced by using a lower magnetization). Magnet properties are known to be dependent on temperature; therefore, the magnet temperature effects on magnetization manipulation and maximum torque properties in VF-PMSMs are investigated in this paper with FEA simulations and experiments. Increased magnet temperature changes the available range of attainable magnetization levels and makes demagnetization occur more easily; therefore, a different current angle and magnetization are needed for maximum torque operation. The temperature effects on high speed magnetization manipulation methods, which are needed for driving cycle loss reduction and full power capability, are evaluated with simulation and experiments on a prototype 80 kW traction machine. A closed loop method for magnetization manipulation that mitigates the effect of temperature is proposed.
Autors: Brent S. Gagas;Kensuke Sasaki;Apoorva Athavale;Takashi Kato;Robert D. Lorenz;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 2189 - 2199
Publisher: IEEE
 
» Magnetic Field Analysis for 3-D Positioning Applications
Abstract:
This paper proposes an analysis of the quasi-stationary magnetic field generated by coils and its applicability to 3-D short-range positioning scenarios. Starting from a theoretical background, an approximation of the induced voltage in a sensor coil is developed and analyzed. Then, the design and performance of a short-range magnetic field-based positioning system is described. The system is realized by using three-axis field generating coils and a three-axis sensor coil. It uses resonance properties to decrease current and power consumption requirements. The system is targeted for simple and low-cost applications, requiring subdecimeter accuracies over short ranges of approximately a couple of meters. The realized prototype, validated through in-field measurements, features a positioning error in the order of 4–5 cm over an area of 1.15 m 1.55 m 0.8 m.
Autors: Valter Pasku;Alessio De Angelis;Guido De Angelis;Antonio Moschitta;Paolo Carbone;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: May 2017, volume: 66, issue:5, pages: 935 - 943
Publisher: IEEE
 
» Magnetic Fluid Based High Precision Temperature Sensor
Abstract:
We have developed a high precision (3.7 mK) temperature sensor using nanomagnetic fluid bearing. The device is based on the basic principle of Charles law (v T). For this, we have prepared kerosene-based magnetic fluid for ferrofluid bearing formation with permanent magnet. The ferrofluid bearing has very low coefficient of friction (), and provides a frictionless movement and perfect sealing. The device is highly sensitive as it uses air as a working media whose coefficient of volume expansion (0.0036) is much larger (20 times) than mercury (0.00018), ethanol (0.00026), and so on usually used in expansion-based thermometers. At constant atmospheric pressure (1 atm), a temperature variation of 1 °C causes a variation of 20 mm (capillary diameter 5 mm) in the position of fluid column. The device has been calibrated and tested using standard calibrated equipment’s. The device shows the high sensitivity of 3.7 (± 0.2) mK and can be used where high accuracy in temperature measurements is required. The device sensitivity and range is easily customizable. The device is capable of finding many useful applications, viz., standards and the calibration of thermometers.
Autors: Saurabh Pathak;Komal Jain; Noorjahan;Vinod Kumar;Rajendra Prasad Pant;
Appeared in: IEEE Sensors Journal
Publication date: May 2017, volume: 17, issue:9, pages: 2670 - 2675
Publisher: IEEE
 
» Magneto–Lithography, a Simple and Inexpensive Method for High Throughput, Surface Patterning
Abstract:
Magneto-lithography (ML) is based on patterning magnetic field on a substrate, using paramagnetic or diamagnetic masks, that defines the shape and strength of the magnetic field. ML is a “bottom-up” method but at the same time, it provides desired high-throughput capabilities for mass production. It is based on applying a magnetic field on the substrate using paramagnetic metal masks that define the spatial distribution and shape of the applied field. The second component in ML is ferromagnetic nanoparticles that are assembled onto the substrate according to the field induced by the mask. We demonstrate the use of various methods of ML for common microelectronic processes such as etching and deposition.
Autors: Amos Bardea;A. Yoffe;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: May 2017, volume: 16, issue:3, pages: 439 - 444
Publisher: IEEE
 
» Maintenance strategy based on reliability analytical models for three parallel mechanical transformation machines
Abstract:
The purpose of this article is to formulate a maintenance strategy for three parallel machines in a mechanical manufacture. The research method was the quantitative modeling, based on analytical models. Time between failures (TBF) and time-to-repair (TTR) data since April 2014 to September 2015 were modelled for the three machines. Weibull distribution fitted all the TBF data. Lognormal distribution fitted TTR for machine 3. The availability Av(t) were calculated for each machine, remaining between 97% to 98%. Based on analytical models, it was defined that the best maintenance strategy for the system is the corrective maintenance.
Autors: Miguel Afonso Sellitto;William Brusius Jr;
Appeared in: IEEE Latin America Transactions
Publication date: May 2017, volume: 15, issue:5, pages: 988 - 993
Publisher: IEEE
 
» Making a Difference [From the Editor's Desk]
Abstract:
Presents the introductory editorial for this issue of the publication.
Autors: Lanny Floyd;
Appeared in: IEEE Industry Applications Magazine
Publication date: May 2017, volume: 23, issue:3, pages: 3 - 3
Publisher: IEEE
 
» Malevolent Activity Detection with Hypergraph-Based Models
Abstract:
We propose a hypergraph-based framework for modeling and detecting malevolent activities. The proposed model supports the specification of order-independent sets of action symbols along with temporal and cardinality constraints on the execution of actions. We study and characterize the problems of consistency checking, equivalence, and minimality of hypergraph-based models. In addition, we define and characterize the general activity detection problem, that amounts to finding all subsequences that represent a malevolent activity in a sequence of logged actions. Since the problem is intractable, we also develop an index data structure that allows the security expert to efficiently extract occurrences of activities of interest.
Autors: Antonella Guzzo;Andrea Pugliese;Antonino Rullo;Domenico Saccà;Antonio Piccolo;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: May 2017, volume: 29, issue:5, pages: 1115 - 1128
Publisher: IEEE
 
» Managing New Technology Using Malleable Profit Functions
Abstract:
Technological innovation drives economic growth, and the pioneering activity of scientists and engineers produce technological innovation. We provide a mathematical model of pioneering strategic choice by adopting a perspective familiar to microeconomics, but less common in the engineering management literature. Instead of focusing on the specific features of a pioneer's technology, we focus on the malleability of the profit equation involved. By considering the arguments of the profit function (i.e., entry and variable costs and potential market demand) as strategic levers, we derive propositions that identify the ranges of actions (lever pulling) available to managers to protect (and even increase) entrepreneurial rents in a simple yet robust partial equilibrium case. For each lever, we show that there are several value ranges (intervals) and that the pioneer's incentives vary across these intervals. In addition, for each lever, we identify the existence of nontrivial profit discontinuities that change the pioneer's incentives in surprising ways and lead to counterintuitive strategic choices. Lastly, we show that for some range of each lever's values, welfare-improving transfer payments are possible and, therefore, pioneers and policy-makers both have an incentive to bargain. As in the case of patents, these transfers encourage the introduction of new technologies.
Autors: Richard Arend;Moren Levesque;Maria Minniti;
Appeared in: IEEE Transactions on Engineering Management
Publication date: May 2017, volume: 64, issue:2, pages: 120 - 133
Publisher: IEEE
 
» Mapping Thermokarst Lakes on the Qinghai–Tibet Plateau Using Nonlocal Active Contours in Chinese GaoFen-2 Multispectral Imagery
Abstract:
In order to monitor the response of thermokarst lakes on the Qinghai–Tibet Plateau (QTP) to rapid climatic changes and human activities, an automated method for extracting shorelines from Chinese GaoFen-2 (GF-2) imagery is proposed. First, the water index (WI) images and the potential lake areas are calculated from the preprocessed multispectral imagery and digital elevation model data, respectively. Second, the initial segmentation obtained by global thresholding of the WI images and masking in the potential lake areas are used to implement the contour initialization of active contours models efficiently. Finally, the nonlocal active contours (NLAC) approach is applied to refine the initial segmentation of the WI images, and the final shoreline vector files are produced by some simple and automatic postprocessing steps. Experiments on the GF-2 imagery demonstrate that 1) by exploiting the capability of WI to locate the approximate shoreline effectively around the evolving contour, the processing time of the proposed method can be saved significantly; 2) the NLAC approach can efficiently identify the shoreline by integrating the nonlocal interactions between pairs of patches inside and outside the lake; and 3) the proposed method can conveniently adapt to the multitemporal and multifeature image analysis. Using the manual digitized shorelines as the reference data, an average error of less than one pixel with standard deviation of 0.1320 can be obtained. These results prove that the proposed method is feasible for the identification and monitoring of thermokarst lakes on the QTP.
Autors: Bangsen Tian;Zhen Li;Meimei Zhang;Lei Huang;Yubao Qiu;Zhixian Li;Panpan Tang;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: May 2017, volume: 10, issue:5, pages: 1687 - 1700
Publisher: IEEE
 
» Matchable-Observable Linear Models and Direct Filter Tuning: An Approach to Multivariable Identification
Abstract:
Identification of linear time-invariant multivariable systems can best be understood as comprising three separate problems: selection of system model structure, filter design, and parameter estimation itself. Approaching the first using matchable-observable models originally developed in the adaptive control literature and the second via direct or derivative-free optimization, effective least-squares algorithms can be used for parameter estimation. The accuracy, robustness and moderate computational demands of the methods proposed are demonstrated via simulations with randomly generated models and applied to identification using real process data. The results obtained are comparable or superior to the best results obtained using standard implementations of the algorithms described in the literature.
Autors: Rodrigo Alvite Romano;Felipe Pait;
Appeared in: IEEE Transactions on Automatic Control
Publication date: May 2017, volume: 62, issue:5, pages: 2180 - 2193
Publisher: IEEE
 
» Matching Network Elimination in Broadband Rectennas for High-Efficiency Wireless Power Transfer and Energy Harvesting
Abstract:
Impedance matching networks for nonlinear devices such as amplifiers and rectifiers are normally very challenging to design, particularly for broadband and multiband devices. A novel design concept for a broadband high-efficiency rectenna without using matching networks is presented in this paper for the first time. An off-center-fed dipole antenna with relatively high input impedance over a wide frequency band is proposed. The antenna impedance can be tuned to the desired value and directly provides a complex conjugate match to the impedance of a rectifier. The received RF power by the antenna can be delivered to the rectifier efficiently without using impedance matching networks; thus, the proposed rectenna is of a simple structure, low cost, and compact size. In addition, the rectenna can work well under different operating conditions and using different types of rectifying diodes. A rectenna has been designed and made based on this concept. The measured results show that the rectenna is of high power conversion efficiency (more than 60%) in two wide bands, which are 0.9–1.1 and 1.8–2.5 GHz, for mobile, Wi-Fi, and ISM bands. Moreover, by using different diodes, the rectenna can maintain its wide bandwidth and high efficiency over a wide range of input power levels (from 0 to 23 dBm) and load values (from 200 to 2000 Ω). It is, therefore, suitable for high-efficiency wireless power transfer or energy harvesting applications. The proposed rectenna is general and simple in structure without the need for a matching network hence is of great significance for many applications.
Autors: Chaoyun Song;Yi Huang;Jiafeng Zhou;Paul Carter;Sheng Yuan;Qian Xu;Zhouxiang Fei;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: May 2017, volume: 64, issue:5, pages: 3950 - 3961
Publisher: IEEE
 
» MAVEN: An Algorithm for Multi-Parametric Automated Segmentation of Brain Veins From Gradient Echo Acquisitions
Abstract:
Cerebral vein analysis provides a chance to study, from an unusual viewpoint, an entire class of brain diseases, including neurodegenerative disorders and traumatic brain injuries. Manual segmentation approaches can be used to assess vascular anatomy, but they are observer-dependent and time-consuming; therefore, automated approaches are desirable, as they also improve reproducibility. In this paper, a new, fully automated algorithm, based on structural, morphological, and relaxometric information, is proposed to segment the entire cerebral venous system from MR images. The algorithm for multi-parametric automated segmentation of brain VEiNs (MAVEN) is based on a combined investigation of multi-parametric information that allows for rejection of false positives and detection of thin vessels. The method is tested on gradient echo brain data sets acquired at 1.5, 3, and 7 T. It is compared to previous methods against manual segmentation, and its inter-scan reproducibility is assessed. The achieved accuracy and reproducibility are good, meaning that MAVEN outperforms previous methods on both quantitative and qualitative analyses. It is usable at all the field strengths explored, showing comparable accuracy scores, with no need for algorithm parameter adjustments, and thus, it is a promising candidate for the characterization of the venous tree topology.
Autors: Serena Monti;Sirio Cocozza;Pasquale Borrelli;Sina Straub;Mark E. Ladd;Marco Salvatore;Enrico Tedeschi;Giuseppe Palma;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: May 2017, volume: 36, issue:5, pages: 1054 - 1065
Publisher: IEEE
 
» Maximum Achievable Power Conversion Efficiency Obtained Through an Optimized Rectenna Structure for RF Energy Harvesting
Abstract:
High-efficiency rectennas for radio frequency (RF) energy harvesting have been studied for decades, but most of the literature straightforwardly applies the rectenna aiming at dedicated RF sources to this situation, even though the level of input power is significantly different. Since previous studies address antenna design collecting more ambient RF power, the improvement of power conversion efficiency (PCE) has emerged in a scattered way, because the theoretical limit of PCE has not yet been characterized, and the optimal rectenna structure approaching such maximum PCE is still uninvestigated. In this paper, we characterize the performance limit of rectennas with input power ranging from −20 to 0 dBm, proposing optimal rectenna design demonstrating the maximum PCE. The maximum achievable PCE is cast into a mathematical programming problem. Solving this optimization model clarifies the effect of design factors, including operational frequencies, rectifier topologies, and parameterization. To achieve the maximum PCE, our investigation shows that the optimal rectenna structure should not only optimize those design factors but also eliminate the matching circuit between an antenna and a rectifier for ultralow-power scenarios. The resultant PCE at 2.45 GHz is 61.4% and 31.8% at −5 and −15 dBm, respectively, closely approaching the theoretical bound.
Autors: Yen-Sheng Chen;Cheng-Wei Chiu;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: May 2017, volume: 65, issue:5, pages: 2305 - 2317
Publisher: IEEE
 
» May the Force Be with You: The Future of Force-Sensitive Authentication
Abstract:
Modern smartphones provide a rich set of possible touchscreen interactions, but most authentication schemes still rely on simple digit or character input. Previous studies examined the shortcomings of such schemes (digit-PINs, for example). Here, the authors discuss the potential of a new PIN type called force-PINs. The idea behind this approach is to augment the security of digit-PINs by assigning a binary pressure value to each digit in the sequence. By adding this (practically) invisible pressure component, force-PINs help users select stronger PINs that are harder to observe. The authors also discuss implications for future research on force-sensitive authentication.
Autors: Katharina Krombholz;Thomas Hupperich;Thorsten Holz;
Appeared in: IEEE Internet Computing
Publication date: May 2017, volume: 21, issue:3, pages: 64 - 69
Publisher: IEEE
 
» Mean-Field Dynamics of Inter-Switching Memes Competing Over Multiplex Social Networks
Abstract:
This letter characterizes the intertwined behavior of a susceptible-infected-susceptible epidemic model involving multiple mutually exclusive memes, each competing over distinct contact planes of an undirected multi-layer social network, with the possibility of inter-switching. Based on the mean-field theory, we contrast and derive closed-form analytical expressions for the steady-state thresholds that govern the transitions between extinction, co-existence, and absolute dominance of the inter-switchable memes. Moreover, a non-linear optimization formulation is presented to determine the optimal budget allocation for controlling the switching rates to a particular co-existing meme. Validated by simulations, the impact of switching on the tipping thresholds and their implications in reality are demonstrated using data extracted from online social networks.
Autors: Aresh Dadlani;Muthukrishnan Senthil Kumar;Manikanta Gowtham Maddi;Kiseon Kim;
Appeared in: IEEE Communications Letters
Publication date: May 2017, volume: 21, issue:5, pages: 967 - 970
Publisher: IEEE
 
» Measurement and Modeling of Angular Spreads of Three-Dimensional Urban Street Radio Channels
Abstract:
By utilizing planar antenna arrays, a base station (BS) by the roadside can exploit two-dimensional (2-D) sectorization and beamforming to connect dense pedestrians and vehicles in a street. The azimuth and elevation angular spreads of the street radio channels are critical for the spatial multiplexing performance. In this paper, by utilizing a multiple-input–multiple-output (MIMO) channel sounder equipped with two uniformed planar antenna arrays, the three-dimensional (3-D) multipath propagations in urban macrocellular street canyon environments were measured and modeled, with the focus on the dynamics of the angular spreads along the streets. The transmitter (emulating a user equipment, UE) was placed at 100 and 95 positions in two streets for the line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios, respectively. The azimuth/elevation angle-of-arrival (AoA/EoA) and the root-mean-square azimuth/elevation spread of arrivals (ASA/ESA) at each position were measured. Contrary to the expected monotonous change of the angular spreads with respect to the UE–BS distance, the measurement results show that, in the LOS scenario, ASA and ESA have a positive correlation with the UE–BS distance in an open street but a negative correlation in a closed street. In the NLOS scenario, the correlation is positive when the UE is close to a building without the over-rooftop diffraction, but the correlation is reversed if such a Quasi-LOS path exists. The 2-D arrival profiles of the ray clusters have been observed, and their impacts on the angular spreads are analyzed in different propagation environments. By comparing multiple candidate fitting functions, the lognormal distribution models for ASA and ESA are proposed. In addition, the channel delay spread (DS) was also measured along the streets and positive correlations among ASA, ESA, and DS have been found. This work can help to est- blish the 3-D spatial channel models for advanced MIMO technologies and is also valuable for future channel measurements.
Autors: Ruonan Zhang;Xiaofeng Lu;Jianping Zhao;Lin Cai;Jiao Wang;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 3555 - 3570
Publisher: IEEE
 
» Measurement of the Mass Flow and Velocity Distributions of Pulverized Fuel in Primary Air Pipes Using Electrostatic Sensing Techniques
Abstract:
Online measurement of pulverized fuel (PF) distribution between primary air pipes on a coal-fired power plant is of great importance to achieve balanced fuel supply to the boiler for increased combustion efficiency and reduced pollutant emissions. An instrumentation system using multiple electrostatic sensing heads is developed and installed on 510-mm bore primary air pipes on the same mill of a 600-MW coal-fired boiler unit for the measurement of PF mass flow and velocity distributions. An array of electrostatic electrodes with different axial widths is housed in a sensing head. An electrode with a greater axial width and three narrower electrodes are used to derive the electrostatic signals for the determination of PF mass flow rate and velocity, respectively. The PF velocity is determined by multiple cross correlation of the electrostatic signals from the narrow electrodes. The measured PF velocity is applied on the root-mean-square magnitude of the measured electrostatic signal from the wide electrode for the calibration of PF mass flow rate. On-plant comparison trials of the developed system were conducted under five typical operating conditions after a system calibration test. Isokinetic sampling equipment is used to obtain reference data to evaluate the performance of the developed system. Experimental data demonstrate that the developed system is effective and reliable for the online continuous measurement of the mass flow and velocity distributions between the primary air pipes of the same mill.
Autors: Xiangchen Qian;Yong Yan;Xiaobin Huang;Yonghui Hu;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: May 2017, volume: 66, issue:5, pages: 944 - 952
Publisher: IEEE
 
» Measurement-Directed Reduction of Dynamic Models in Power Systems
Abstract:
The paper describes a new model reduction procedure tailored to power systems. It uses measurement data to devise a family of reduced order nonlinear models while retaining physical interpretability of parameters and equations. The manifold boundary approximation method (MBAM) uses the Fisher information matrix calculated from measurements to identify the least relevant parameter combination in the original model. Next, it numerically constructs a geodesic on the corresponding statistical manifold originating from the initial parameters in the least relevant parameter direction until a manifold boundary is found. MBAM then identifies a limiting approximation in the mathematical form of the model and removes one parameter combination. The simplified model is recalibrated by fitting its behavior to that of the original model, and the process is repeated as appropriate. MBAM is demonstrated on the example of a synchronous generator (SG), which has been treated extensively in the literature. Implications of the proposed model reduction procedure on large power system models are illustrated on a 441-bus, 72-SG dynamical model.
Autors: Mark K. Transtrum;Andrija T. Sarić;Aleksandar M. Stanković;
Appeared in: IEEE Transactions on Power Systems
Publication date: May 2017, volume: 32, issue:3, pages: 2243 - 2253
Publisher: IEEE
 
» Measuring and Understanding RRC State Machine Optimization in Light of Recent Advancements
Abstract:
Broadband mobile networks utilize a radio resource control (RRC) state machine to allocate scarce radio resources. Current implementations introduce high latencies and cross-layer degradation. Recently, the RRC enhancements, continuous packet connectivity (CPC), and the enhanced forward access channel (Enhanced FACH), have emerged in UMTS. We measure the availability and performance of these enhancements on a network serving a market with a population in the millions. We demonstrate that these enhancements offer significant reductions in latency, mobile device energy consumption, and improved end user experience. We develop new over-the-air measurements that resolve existing limitations in measuring RRC parameters. We find CPC provides significant benefits with minimal resource costs, prompting us to rethink past optimization strategies. We examine the cross-layer performance of CPC and Enhanced FACH, concluding that CPC provides reductions in mobile device energy consumption for many applications. While the performance increase of HS-FACH is substantial, cross-layer performance is limited by the legacy uplink random access channel (RACH), and we conclude full support of Enhanced FACH is necessary to benefit most applications. Given that UMTS growth will exceed LTE for several more years and the greater worldwide deployment of UMTS, our quantitative results should be of great interest to network operators adding capacity to these networks. Finally, these results provide new insights for application developers wishing to optimize performance with these RRC enhancements.
Autors: Xuetao Wei;Theodore Stoner;Joseph Knight;Lei Guo;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: May 2017, volume: 16, issue:5, pages: 1330 - 1342
Publisher: IEEE
 
» Measuring Azimuth Deformation With L-Band ALOS-2 ScanSAR Interferometry
Abstract:
We analyze the methods for measuring azimuth deformation with the L-band Advanced Land Observing Satellite-2 (ALOS-2) scanning synthetic aperture radar (ScanSAR) interferometry. To implement the methods, we extract focused bursts from the ALOS-2 full-aperture product, which is the only product available for ScanSAR interferometry at present. The extracted bursts are properly processed to measure azimuth deformation using interferometric phase. We apply the range split-spectrum method to ScanSAR to estimate the differential ionospheric phase of the interferogram, and take the azimuth derivative of the differential ionospheric phase to mitigate the relative azimuth shift caused by ionosphere. For the first time, azimuth deformation of a large earthquake (April 25, 2015 Nepal earthquake) is nearly completely measured by the L-band ScanSAR interferometry with moderate precision. The result is validated by the azimuth deformation measured by incoherent cross correlation using a pair of high-resolution RADARSAT-2 images. In addition to the final azimuth deformation, we show the possibility of processing full-aperture ScanSAR product using a burst-by-burst approach to form regular interferograms. We also show the recent strong large-scale ionospheric effects on the L-band ALOS-2 ScanSAR interferograms. Other possible applications of this paper include measuring the movement of glaciers.
Autors: Cunren Liang;Eric J. Fielding;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: May 2017, volume: 55, issue:5, pages: 2725 - 2738
Publisher: IEEE
 
» Measuring Vehicle Velocity in Real Time Using Modulated Motion Blur of Camera Image Data
Abstract:
In this paper, a novel sensor system is presented for estimating the velocity using a modulated motion blur. By moving a camera mounted on the vehicle body with a specific pattern when the vehicle is moving, the blurred image includes the information of the vehicle velocity of the camera itself. It will be shown that the inclinations of motion blur in a scene are directly related to the velocity vector of the vehicle and the modulation speed. The proposed approach invariant to the exposure time provides the magnitude and direction of the velocity vector with high accuracy and high reliability. In contrast to other approaches using a camera image, our approach requires only 256 × 192 [pixel], and the proposed algorithm is simple and fast. The efficacy of the proposed method is demonstrated through simulations and experiments. The experimental results present empirical evidence to support that the proposed system is robust to climate changes such as rainy or snowy weather. The proposed system is expected to be applicable to vehicular technologies such as the vehicle dynamics controlling system or the vehicle positioning system.
Autors: Minyoung Lee;Kyung-Soo Kim;Soohyun Kim;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: May 2017, volume: 66, issue:5, pages: 3659 - 3673
Publisher: IEEE
 
» Mechanomyography Assisted Myoeletric Sensing for Upper-Extremity Prostheses: A Hybrid Approach
Abstract:
The myoelectric upper-limb prosthetic manipulation is inherently limited by the unreliable sensor-skin interface. This paper presents a hybrid approach to overcome the limitation of electromyography (EMG) through mechanomyography (MMG) assisted myoelectric sensing. An integrated hybrid sensor system was developed for simultaneous EMG and MMG measurement. The hybrid system formed a platform to capture muscular activations in different frequencies. To evaluate the effectiveness of hybrid EMG-MMG sensing, hand motion experiments have been carried out on seven able-bodied and two transradial amputee subjects. It convincingly demonstrated, a significantly () improved classification accuracy (CA). Furthermore, the CA was compensated by 8.7% ~ 33.7% in the presence of 2 ~ 3 fault EMG channels. These results suggest that MMG assisted myoelectric sensing can improve the control performance and robustness. It has great potential to promote the clinical application of multi-functional prosthetic hand with hybrid EMG-MMG sensor system.
Autors: Weichao Guo;Xinjun Sheng;Honghai Liu;Xiangyang Zhu;
Appeared in: IEEE Sensors Journal
Publication date: May 2017, volume: 17, issue:10, pages: 3100 - 3108
Publisher: IEEE
 
» Meetings Calendar
Abstract:
The following list of meetings, conferences, and symposia is provided as a reader service and does not constitute endorsement by the IEEE or the IEEE Dielectrics and Electrical Insulation Society. This calendar can also be found at http://sites.ieee.org/deis.
Autors: Davide Fabiani;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: May 2017, volume: 33, issue:3, pages: 46 - 47
Publisher: IEEE
 
» Method of Generating Femtosecond Cylindrical Vector Beams Using Broadband Mode Converter
Abstract:
We experimentally obtain femtosecond cylindrical vector beams based on a mode-locked fiber laser (MLFL) by using a fused few-mode coupler. Pulses of 300 fs duration with radially and azimuthally polarized modes are directly delivered at the central wavelength of 1566 nm. The fused few-mode fiber coupler inserted inside the cavity acts as a mode converter from LP01 mode to LP11 mode with a wide bandwidth over 100 nm. The proof-of-concept generation of femtosecond cylindrical vector beams is efficient and useful in MLFLs.
Autors: Feng Wang;Fan Shi;Teng Wang;Fufei Pang;Tingyun Wang;Xianglong Zeng;
Appeared in: IEEE Photonics Technology Letters
Publication date: May 2017, volume: 29, issue:9, pages: 747 - 750
Publisher: IEEE
 
» Mg Doping to Simultaneously Improve the Electrical Performance and Stability of MgInO Thin-Film Transistors
Abstract:
In this paper, we have fabricated the magnesium-doped indium oxide (MgInO) thin-film transistors (TFTs) by solution process and evaluate the electrical characteristics and stability under temperature stress and positive bias stress. The MgInO TFTs show a decrease of off-state current ( and an increase of threshold voltage ( with the increase of Mg doping concentration. For MgInO TFT with 0.75 mol% Mg doping concentration, it shows an excellent electrical characteristic (the field effectmobility of 13.77 cm, the threshold voltage of 2.84 V, and subthreshold swing value of 0.85 V/decade) and a good stability of temperature stress and positive bias stress. The performance enhancement of MgInO TFTs is attributed to the reduced density of states and the lower interface trap density by the optimized Mg doping concentration, which is first verified by the temperature-dependent field effect measurement and capacitance–voltage method.
Autors: Cheng-Yu Zhao;Jun Li;De-Yao Zhong;Chuan-Xin Huang;Jian-Hua Zhang;Xi-Feng Li;Xue-Yin Jiang;Zhi-Lin Zhang;
Appeared in: IEEE Transactions on Electron Devices
Publication date: May 2017, volume: 64, issue:5, pages: 2216 - 2220
Publisher: IEEE
 
» Microplasma Actuator for EHD Induced Flow
Abstract:
Dielectric barrier discharge microplasma actuator was used for flow modification. The actuator was energized at a relatively low discharge voltage of about 1 kV. The movement of incense particles was tracked by the high-speed camera. A modulated ac voltage was applied to electrodes. It was observed using a high-speed camera how the flow velocity and direction was changed at different duty ratios of the applied voltage. The numerical simulation of the flow was carried out using the fluid model, which considers the electric potential to be the combination of the potential due the external electric field and the charge density of plasma. Based on these potentials, the body force was calculated. Furthermore, the body force was implemented in the Navier–Stokes equations and the simulated flow was obtained. The numerical results matched the obtained results in experiments.
Autors: Marius Blajan;Yoshinori Mizuno;Akihiko Ito;Kazuo Shimizu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: May 2017, volume: 53, issue:3, pages: 2409 - 2415
Publisher: IEEE
 

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