Electrical and Electronics Engineering publications abstract of: 03-2017 sorted by title, page: 14

» Patients' Adoption of WSN-Based Smart Home Healthcare Systems: An Integrated Model of Facilitators and Barriers
Abstract:
Background: Patient-centered care emphasizes care coordination and communication through active involvement of patients, their families, physicians, and other professionals to improve decision making. Smart telecommunication technology and the Internet of Things, such as wireless-sensor-network-based smart home healthcare systems (WSN-SHHS) facilitate communication and collaboration among these different roles. Research problem: Despite the great potential of such systems to improve the quality and experience, and lower the cost of health care, the technology has not been widely adopted partly due to an inadequate understanding of user expectations, needs, and preferences. This study addresses facilitators and barriers with regard to WSN-SHHS adoption by identifying important sociotechnical, cognitive, affective, and contextual factors. Research questions: What are the main facilitators and barriers of patients' adoption of WSN-SHHS? How can we contextualize a generic technology adoption model for WSN-SHHS that takes into account unique characteristics of the domain? Literature review: We surveyed the literature in WSN-SHHS research and application, technology adoption theories, and the pleasure-arousal-dominance emotional state model. We discovered that WSN-SHHS research has focused on technology development but has given little attention to the issue of patients' adoption. Methodology: We used a mixed method design that combined an interview and survey over two studies. Participants were recruited from home healthcare agencies in the eastern US. In semistructured interviews, we collected data from 15 home healthcare patients and medical professionals, and analyzed the data using Kvale's approach. In our online- and paper-based surveys, we analyzed the data from 140 respondents using partial least square. Results and conclusions: We identified several new constructs in relation to W- N-SHHS adoption, including human detachment concerns, privacy concerns, life-quality expectancy and cost concerns. In addition, we confirmed the constructs from the general adoption model. Based on the findings of the qualitative study, the researchers created a research model. The quantitative study provided empirical support for the model, which has substantial predictive power accounting for more than half of the variance in WSN-SHHS adoption. In particular, our findings reveal that human detachment concerns rather than performance expectancy is the strongest predictor of patients' adoption of WSN-SHHS.
Autors: Ahmad Alaiad;Lina Zhou;
Appeared in: IEEE Transactions on Professional Communication
Publication date: Mar 2017, volume: 60, issue:1, pages: 4 - 23
Publisher: IEEE
 
» Patron Allocation for Group Services Under Lower Bound Constraints
Abstract:
Group services are highly important for a variety of computing application domains. In this paper, we study the fundamental problem of allocating a set of service patrons to a set of service groups in an attempt to maximize the total profit gained by the grouping platform. The problem under consideration is unique in that group service is not provided at all unless its lower bound requirement is satisfied. In addition, we allow each service patron to join multiple groups. In this paper, after proving the hardness property of the problem, we focus first on a special case of the problem. To this end, we propose two approaches. One aims at providing a suboptimal solution using a 1/2-approximation algorithm. The other approach turns to seeking an optimal solution using a branch and bound technique. For this purpose, we introduce a theorem that captures a useful property of an optimal allocation. Based on this theorem, we design an efficient branch and bound algorithm to find an optimal solution. We then extend these methods to solve the general problem. Extensive experiments show that our branch and bound algorithm is able to obtain an optimal solution with a small amount of computation time in many different settings.
Autors: Hsiang-Jen Hong;Ge-Ming Chiu;Shiow-yang Wu;Tien-Ruey Hsiang;Tai-Lin Chin;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Mar 2017, volume: 28, issue:3, pages: 850 - 862
Publisher: IEEE
 
» Pay It Forward
Abstract:
How many times have we heard the phrase pay it forward? Just what does this phrase mean? It is not new: according to sources, it has been around since the third century B.C., with the author unknown. How has it survived for such a long period, and how is it interpreted today?
Autors: Raymond E. Floyd;
Appeared in: IEEE Potentials
Publication date: Mar 2017, volume: 36, issue:2, pages: 5 - 47
Publisher: IEEE
 
» PDFS: Partially Dedupped File System for Primary Workloads
Abstract:
Primary storage dedup is difficult to be accomplished because of challenges to achieve low IO latency and high throughput while eliminating data redundancy effectively in the critical IO Path. In this paper, we design and implement the PDFS, a partially dedupped file system for primary workloads, which is built on a generalized framework using partial data lookup for efficient searching of redundant data in quickly chosen data subsets instead of the whole data. PDFS improves IO latency and throughput systematically by techniques including write path optimization, data dedup parallelization and write order preserving. Such design choices bring dedup to the masses for general primary workloads. Experimental results show that PDFS achieves 74-99 percent of the theoretical maximum dedup ratio with very small or even negative performance degradations compared with main stream file systems without dedup support. Discussions about varied configuring experiences of PDFS are also carried out.
Autors: Hongliang Yu;Xu Zhang;Wei Huang;Weimin Zheng;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Mar 2017, volume: 28, issue:3, pages: 863 - 876
Publisher: IEEE
 
» Penalized Linear Discriminant Analysis of Hyperspectral Imagery for Noise Removal
Abstract:
The existence of noise in hyperspectral ima-gery (HSI) seriously affects image quality. Noise removal is one of the most important and challenging tasks to complete before hyperspectral information extraction. Though many advances have been made in alleviating the effect of noise, problems, including a high correlation among bands and predefined structure of noise covariance, still prevent us from the effective implementation of hyperspectral denoising. In this letter, a new algorithm named the penalized linear discriminant analysis (PLDA) and noise adjusted principal components transformation (NAPCT) was proposed. PLDA was applied to search for the best noise covariance structure, while the NAPCT was employed to remove the noise. The results of the tests with both HJ-1A HSI and EO-1 Hyperion showed that the proposed PLDA-NAPCT method could remove the noise effectively and that it could preserve the spectral fidelity of the restored hyperspectral images. Specifically, the recovered spectral curves using the proposed method are visually more similar to the original image compared with the control methods; quantitative matrices, including the noise reduction ration and mean relative deviation, also showed that the PLDA-NAPCT produced less bias than the control methods. Furthermore, the PLDA-NAPCT method is sensor-independent, and it could be easily adapted for removing the noise from different sensors.
Autors: Ming Lu;Luojia Hu;Tianxiang Yue;Ziyue Chen;Bin Chen;Xiaoqiang Lu;Bing Xu;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Mar 2017, volume: 14, issue:3, pages: 359 - 363
Publisher: IEEE
 
» Perceived Cooling Using Asymmetrically-Applied Hot and Cold Stimuli
Abstract:
Temperature perception is a highly nonlinear phenomenon with faster rates of change being perceived at much lower thresholds than slower rates. This paper presents a method that takes advantage of this nonlinear characteristic to generate a perception of continuous cooling even though the average temperature is not changing. The method uses multiple thermal actuators so that a few are cooling quickly while the rest of the actuators are heating slowly. The slowly-heating actuators are below the perceptual threshold temperature change and hence are not perceived, while the quickly-cooling actuators are above the perceptual temperature change, hence are perceived. As a result, a feeling of decreasing temperature was elicited, when in fact, there was no net change in the temperature of the skin. Three sets of judiciously designed experiments were conducted in this study, investigating the effects of actuator sizes, forearm measurement locations, patterns of actuator layout, and various heating/cooling time cycles. Our results showed that 19 out 21 participants perceived the continuous cooling effect as hypothesized. Our research indicates that the measurement location, heating/cooling cycle times, and arrangement of the actuators affect the perception of continuous cooling.
Autors: Ahmad Manasrah;Nathan Crane;Rasim Guldiken;Kyle B. Reed;
Appeared in: IEEE Transactions on Haptics
Publication date: Mar 2017, volume: 10, issue:1, pages: 75 - 83
Publisher: IEEE
 
» Perceiving Learning at a Glance: A Systematic Literature Review of Learning Dashboard Research
Abstract:
This paper presents a systematic literature review of the state-of-the-art of research on learning dashboards in the fields of Learning Analytics and Educational Data Mining. Research on learning dashboards aims to identify what data is meaningful to different stakeholders and how data can be presented to support sense-making processes. Learning dashboards are becoming popular due to the increased use of educational technologies, such as Learning Management Systems (LMS) and Massive Open Online Courses (MOOCs). The initial search of five main academic databases and GScholar resulted in 346 papers out of which 55 papers were included in the final analysis. Our review distinguishes different kinds of research studies as well as various aspects of learning dashboards and their maturity regarding evaluation. As the research field is still relatively young, most studies are exploratory and proof-of-concept. The review concludes by offering a definition for learning dashboards and by outlining open issues and future lines of work in the area of learning dashboards. There is a need for longitudinal research in authentic settings and studies that systematically compare different dashboard designs.
Autors: Beat A. Schwendimann;María Jesús Rodríguez-Triana;Andrii Vozniuk;Luis P. Prieto;Mina Shirvani Boroujeni;Adrian Holzer;Denis Gillet;Pierre Dillenbourg;
Appeared in: IEEE Transactions on Learning Technologies
Publication date: Mar 2017, volume: 10, issue:1, pages: 30 - 41
Publisher: IEEE
 
» Perfecting Protection for Interactive Multimedia: A survey of forward errror correction for low-delay interactive applications
Abstract:
Many current and emerging applications require low-latency communication, including interactive voice and video communication, multiplayer gaming, multiperson augmented/virtual reality, and various Internet of Things (IoT) applications. Forward error correction (FEC) codes for low-delay interactive applications have several characteristics that distinguish them from traditional FEC. The encoding and decoding operations must process a stream of data packets in a sequential fashion. Strict latency constraints limit the use of long block lengths, interleaving, or large buffers. Furthermore, these codes must achieve fast recovery from burst losses and yet be robust to other types of loss patterns.
Autors: Ahmed Badr;Ashish Khisti;Wai-Tian Tan;John Apolstolopoulos;
Appeared in: IEEE Signal Processing Magazine
Publication date: Mar 2017, volume: 34, issue:2, pages: 95 - 113
Publisher: IEEE
 
» Performance Analysis and Coherent Guaranteed Cost Control for Uncertain Quantum Systems Using Small Gain and Popov Methods
Abstract:
This technical note extends applications of the quantum small gain and Popov methods from existing results on robust stability to performance analysis results for a class of uncertain quantum systems. This class of systems involves a nominal linear quantum system and is subject to quadratic perturbations in the system Hamiltonian. Based on these two methods, coherent guaranteed cost controllers are designed for a given quantum system to achieve improved control performance. An illustrative example also shows that the quantum Popov approach can obtain less conservative results than the quantum small gain approach for the same uncertain quantum system.
Autors: Chengdi Xiang;Ian R. Petersen;Daoyi Dong;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Mar 2017, volume: 62, issue:3, pages: 1524 - 1529
Publisher: IEEE
 
» Performance Analysis of $L$- Branch Scan-and-Wait Combining (SWC) Over Arbitrarily Correlated Nakagami- $m$ Fading Channels
Abstract:
The performance of - branch scan-and-wait combining (SWC) reception systems over arbitrarily correlated and not necessarily identically distributed Nakagami- fading channels is analyzed and evaluated. First, a fast convergent infinite series representation for the SWC output signal-to-noise ratio (SNR) is presented. This expression is used to obtain analytical expressions in the form of infinite series for the average error probability performance of various modulation schemes for integer values of as well as the average number of paths estimation and the average waiting time (AWT) of -branch SWC receivers for arbitrary values of . The numerically obtained results have shown that the performance expressions converge very fast to their exact analytical values. It was found that the convergence speed depends on the correlation and operating SNR values as well as the Nakagami - parameter. In addition to the analytical results, complementary computer simulated performance evaluation results have been obtained by means of Monte Carlo error counting techniques. The match between these two sets of results has verified the accuracy of the proposed mathematical analysis. Furthermore, it is revealed that, at the expense of a negligible AWT, the average error probability performance of SWC receivers is always superior to that of switch-and-examine combining receivers and, in certain cases, to that of maximal-ratio combining receivers.
Autors: George C. Alexandropoulos;P. Takis Mathiopoulos;Pingzhi Fan;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Mar 2017, volume: 66, issue:3, pages: 2868 - 2874
Publisher: IEEE
 
» Performance Analysis of Cooperative Systems With Unreliable Backhauls and Selection Combining
Abstract:
In this paper, a cooperative wireless system with unreliable wireless backhaul connections is investigated. To increase the throughput and maximize the receiver signal-to-noise ratio (SNR), a selection combining (SC) protocol is employed. Cooperative transmitters are connected to the control unit (CU) via independent but unreliable wireless backhaul connections. Simultaneously taking into account the reliability of each backhaul and different fading conditions of Nakagami- fading channels, the statistical properties of the effective SNR (e-SNR) at the receiver are investigated. Closed-form expressions are derived for several performance metrics, including the outage probability, average spectral efficiency (ASE), and average symbol error rate (ASER). The effects of backhaul reliability on these performance metrics are also investigated. The scaling relationship between the convergence behavior of these performance metrics and the conventional diversity gain is also analytically investigated in the asymptotic high-SNR regime. Monte Carlo simulations are conducted to verify the derived impact of backhaul reliability on the performance.
Autors: Kyeong Jin Kim;Talha Ahmed Khan;Philip V. Orlik;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Mar 2017, volume: 66, issue:3, pages: 2448 - 2461
Publisher: IEEE
 
» Performance Analysis of IEEE 802.11p DCF for Multiplatooning Communications With Autonomous Vehicles
Abstract:
Platooning has been identified as a promising framework to improve road capacity, on-road safety, and energy efficiency. Enabling communications among vehicles in platoons is expected to enhance platoon control by keeping constant intervehicle and interplatoon distances. Characterizing the performance of intra- and interplatoon communications in terms of throughput and packet transmission delays is crucial for validating the effectiveness of information sharing on platoon control. In this paper, we introduce an IEEE 802.11p-based communication model for multiplatooning (a chain of platoons) scenarios. We present a probabilistic performance analysis of distributed-coordination-function-based intra- and interplatoon communications. Expressions for the transmission attempt probability, collision probability, packet delay, packet-dropping probability, and network throughput are derived. Numerical results show that the performance of interplatoon communications is affected by the transmissions of the first and last vehicles in a multiplatoon. This effect is reduced with an increase of the platoon number in the multiplatoon. In addition, the communication performance for three typical multiplatooning application scenarios is investigated, indicating that the IEEE 802.11p-based communication can support the timely delivery of vehicle information among platoons for diverse on-road applications.
Autors: Haixia Peng;Dazhou Li;Khadige Abboud;Haibo Zhou;Hai Zhao;Weihua Zhuang;Xuemin (Sherman) Shen;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Mar 2017, volume: 66, issue:3, pages: 2485 - 2498
Publisher: IEEE
 
» Performance Analysis of Nanoscale Single Layer Graphene Pressure Sensors
Abstract:
A nanometer-sized graphene pressure sensor is schematically proposed. The graphene membrane is placed over a square cavity etched onto SiO2 substrate so that the transport is along the armchair direction of the graphene. Two contacts are considered at two ends of the device. Current-pressure characteristic is obtained for various cavity sizes, bias voltages, and temperatures. The device behavior is investigated in terms of sensitivity and linearity error. For sensors with nm2 cavity size, at room temperature, the sensitivity of 2300 pA/A/Pa and linearity error of 1.042% are obtained. The temperature dependent behavior of the proposed device is also investigated. Mechanical behavior is simulated by means of geometric nonlinear analysis and clamped boundary conditions along all sides of the graphene membrane. Electronic simulations are carried out by means of NEGF-tight-binding formalism.
Autors: Majid Sanaeepour;Abolfazl Abedi;Mohammad Javad Sharifi;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Mar 2017, volume: 64, issue:3, pages: 1300 - 1304
Publisher: IEEE
 
» Performance Analysis of Time-Modulated Arrays for the Angle Diversity Reception of Digital Linear Modulated Signals
Abstract:
Diversity occurs whenever several copies of the same transmitted signal arrive at a receiver. Such a situation allows for improving the performance of a wireless communication system transmitting over a radio channel without increasing the transmit power. Previous works have shown that time-modulated arrays are capable of faithfully acquiring digital signals while exploiting angular diversity through the adaptive beamforming of their harmonic patterns. In this work, we take a step further and consider a wireless communication system employing digital linear modulated signals and an innovative receiver that includes a time-modulated array and a maximum ratio combining subsystem. The maximum ratio combiner is adapted to optimally exploit the multipath channel angular diversity. The performance of the system is analyzed in terms of two metrics: the signal-to-noise ratio and the symbol error rate. The results are compared to those achieved with other receivers that include conventional antenna arrays, exhibiting the time-modulated array solution a good tradeoff between performance and hardware complexity.
Autors: Roberto Maneiro-Catoira;Julio C. Brégains;José A. García-Naya;Luis Castedo;Paolo Rocca;Lorenzo Poli;
Appeared in: IEEE Journal of Selected Topics in Signal Processing
Publication date: Mar 2017, volume: 11, issue:2, pages: 247 - 258
Publisher: IEEE
 
» Performance Characterization of Random Pulse Width Modulation Algorithms in Industrial and Commercial Adjustable-Speed Drives
Abstract:
One of the problems of the pulse-width-modulation (PWM)-controlled ac machines is the acoustic noise that could become unacceptable when used in sensitive environments. Random PWM (RPWM) in industrial and commercial adjustable-speed drives (ASD) results in the partial transfer of power from the discrete spectrum (narrowband noise) of the output voltage to the continuous spectrum (wideband noise), with advantageous effects on reducing the acoustic noise in the motor drive system. In this paper, the theoretical power spectrum analysis as the basis for RPWM is presented. Five state-of-the-art RPWM strategies, their voltage, current, and acoustic noise spectra characteristics are quantitatively evaluated. The PWM schemes and theoretical analysis are validated through a 2.2-kW 380-V 50-Hz ASD induction machine experimental setup. The results provide valuable data for practicing engineering community to choose the best option in real-world applications.
Autors: Kevin Lee;Guangtong Shen;Wenxi Yao;Zhengyu Lu;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Mar 2017, volume: 53, issue:2, pages: 1078 - 1087
Publisher: IEEE
 
» Performance Improvement of Deception Jamming Against SAR Based on Minimum Condition Number
Abstract:
This paper proposes a new approach to improve the error performance of the synergy netting deception jamming against synthetic aperture radar (SAR). The existing methods cannot tackle the issue of error amplification induced by the linear equations constructed for jamming coefficients calculation. To handle this problem, we develop an optimal layout for radar receivers to minimize the effect of the error by minimizing the condition number, which measures the sensitivity of the synergy deception jamming system to the perturbation. It is revealed that the devised approach relies little on the SAR kinematic parameters. To further improve the error performance of the jamming system, collaborative receivers, which provide more observations of time difference of arrivals, are introduced to perform a linear least-squares estimation. The error reduction level due to the cooperative receivers is analyzed. Simulation results are provided to illustrate the superiority of the proposed method.
Autors: Bo Zhao;Lei Huang;Feng Zhou;Jihong Zhang;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Mar 2017, volume: 10, issue:3, pages: 1039 - 1055
Publisher: IEEE
 
» Performance of a Seed-Free Disk Magnetohydrodynamic Generator With Self-Excited Joule Heating in the Nozzle
Abstract:
In a seed-free inert-gas disk-shaped magnetohydrodynamic (MHD) generator, the effect of the self-excited Joule heating in the nozzle region on the generator performance has been examined with 2-D – numerical simulations. The working gas (pure inert gas) can be ionized efficiently with the assistance of the self-excited Joule heating in the nozzle located upstream of the generator channel, even for a small, externally applied preionization power (PP). The increase in the ionization degree in the nozzle and the decrease in the optimum electrical conductivity in the generator channel with increase in the magnetic flux density reduce the optimum PP that maximizes the net enthalpy extraction (EE) ratio. For a typical argon disk MHD generator, a maximum net EE ratio of 25% and an isentropic efficiency of 65% can be obtained at a small PP of 0.3% of the inflow enthalpy under a magnetic flux density of 4 T. The enhancement of the ionization degree in the nozzle and the inhomogeneity of the plasma in the vertical direction because of the current concentration near the anode edge are more marked for argon and xenon, with their higher ionization rates, than for helium.
Autors: Manabu Tanaka;Yoshihiro Okuno;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Mar 2017, volume: 45, issue:3, pages: 454 - 460
Publisher: IEEE
 
» Performance of Graded Bandgap HgCdTe Avalanche Photodiode
Abstract:
This paper reports the performance of midwave infrared (MWIR) electron-injection avalanche photodiode (e-APD) fabricated using graded bandgap HgCdTe epilayers. Carrier transport in the e-APD is dominated by drift transport due to the built-in electric field associated with gradient in the bandgap. Carriers encounter fewer collision events before entering the multiplication region as the dead space effect is reduced. On-set of generation and multiplication processes is controlledmore effectively. High gain indicates a reduced in-elastic scattering by phonon-emission due to gradient. Quantum efficiency above 80% is achieved in merely 2–3--thick absorbing layer because of more efficient collection of the photogenerated carriers. Lower generation volume is beneficial in terms of low dark current. The generation is confined in the vicinity of themultiplication region. Generated carriers are readily evacuated from the absorber region under the built-in electric field. An order of magnitude improvement over the state-of-the art performance in MWIR e-APD is achieved by introducing a controlled energy bandgap gradient in the HgCdTe epilayers.
Autors: Anand Singh;A. K. Shukla;Ravinder Pal;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Mar 2017, volume: 64, issue:3, pages: 1146 - 1152
Publisher: IEEE
 
» Performance of Non-orthogonal Multiple Access With a Novel Asynchronous Interference Cancellation Technique
Abstract:
The non-orthogonal multiple access (NOMA) allows one subcarrier to be allocated to more than one user at the same time in an orthogonal frequency division multiplexing (OFDM) system. NOMA is a promising technique to provide high throughput due to frequency reuse within a cell. In this paper, a novel interference cancellation (IC) technique is proposed for asynchronous NOMA systems. The proposed IC technique exploits a triangular pattern to perform the IC from all interfering users for the desired user. The bit error rate and the capacity performance analysis of an uplink NOMA system with the proposed IC technique are presented, along with the comparison to orthogonal frequency division multiple access (OFDMA) systems. The numerical and simulation results show that the NOMA with the proposed asynchronous IC technique outperforms the OFDMA. It is also shown that employing iterative IC provides significant performance gain for NOMA and the number of required iterations depends on the modulation level and the detection method. With hard decision, two iterations are sufficient, and however, with soft decision, two iterations are enough only for low modulation level, and more iterations are desirable for high modulation level.
Autors: Huseyin Haci;Huiling Zhu;Jiangzhou Wang;
Appeared in: IEEE Transactions on Communications
Publication date: Mar 2017, volume: 65, issue:3, pages: 1319 - 1335
Publisher: IEEE
 
» Performance Studies of Underwater Wireless Optical Communication Systems With Spatial Diversity: MIMO Scheme
Abstract:
In this paper, we analytically study the performance of multiple-input multiple-output underwater wireless optical communication (UWOC) systems with ON–OFF keying modulation. To mitigate turbulence-induced fading, which is amongst the major degrading effects of underwater channels on the propagating optical signal, we use spatial diversity over UWOC links. Furthermore, the effects of absorption and scattering are considered in our analysis. We analytically obtain the exact and an upper bound bit error rate (BER) expressions for both optimal and equal gain combining. In order to more effectively calculate the system BER, we apply Gauss-Hermite quadrature formula as well as approximation to the sum of lognormal random variables. We also apply the photon-counting method to evaluate the system BER in the presence of shot noise. Our numerical results indicate an excellent match between the exact and upper bound BER curves. Also, a good match between the analytical results and numerical simulations confirms the accuracy of our derived expressions. Moreover, our results show that spatial diversity can considerably improve the system performance, especially for channels with higher turbulence, e.g., a multiple-input single-output transmission in a 25 m coastal water link with a log-amplitude variance of 0.16 can introduce 8 dB performance improvement at the BER of 10−9.
Autors: Mohammad Vahid Jamali;Jawad A. Salehi;Farhad Akhoundi;
Appeared in: IEEE Transactions on Communications
Publication date: Mar 2017, volume: 65, issue:3, pages: 1176 - 1192
Publisher: IEEE
 
» Performance-Power Evaluation of an OpenCL Implementation of the Simplex Growing Algorithm for Hyperspectral Unmixing
Abstract:
Over the last few years, several new strategies for spectral unmixing of remotely sensed hyperspectral data have been proposed. Many of them have been developed to solve the most time-consuming and relevant step: endmember extraction. However, unmixing algorithms can be computationally very expensive in terms of processing time and energy consumption, a fact that compromises their use in applications under real-time and energy/power constraints. In this letter, we present a new parallel simplex growing algorithm (SGA) for hyperspectral data which exploits the memory hierarchy with operations in single-precision floating point. Those optimizations accelerate the most time-consuming parts of this method using the open computing language (OpenCL) standard. We have evaluated the performance versus energy consumption using the same open standard for parallel programming over a diverse set of heterogeneous platforms. Experiments have been conducted using real hyperspectral images collected by NASA’s Airborne Visible Infrared Imaging Spectrometer and a collection of 24 synthetic hyperspectral images simulated with different sizes and number of endmembers (10–30). Considering the power consumption and OpenCL across all the proposed devices, the analysis presented indicates that the SGA can now be executed in computationally efficient fashion, which was not possible before introducing the parallel implementation described in this letter.
Autors: Sergio Bernabé;Guillermo Botella;José M. R. Navarro;Carlos Orueta;Francisco D. Igual;Manuel Prieto-Matias;Antonio Plaza;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Mar 2017, volume: 14, issue:3, pages: 304 - 308
Publisher: IEEE
 
» Permanent-Magnet Coupled Power Inductor for Multiphase DC–DC Power Converters
Abstract:
Using a coupled power inductor (CPI) in a multiphase dc–dc power converter instead of using multiple single-phase power inductors (PIs) reduces the inductor size and achieves better steady state and transient performances. To further reduce the inductor size and weight used in multiphase power converters, this paper presents a two-phase CPI that utilizes a permanent magnet (PM) to achieve almost doubled saturation current with the same size or equivalently achieve significant size and weight reduction. Operation principle of the presented permanent magnet coupled power inductor (PMCI) and required PM dimensions are derived and used as a design guide. The three-dimensional physical model of the PMCI is developed by using ANSYS/Maxwell software package to “visualize” the saturation current doubling. The fabricated PMCI design, with specifications of 24 A/phase, ∼4.25 μH/phase equivalent steady-state inductance, and ∼2.3 μH equivalent transient inductance, is tested in a 4–8 V two-phase dc–dc boost power converter with up to 50 A input current. Results show that compared to a conventional CPI design with the same size, weight, and inductance, the fabricated PMCI almost doubles the saturation current (from 13 to 24 A/phase). Compared to another CPI with a larger size but with even a smaller saturation current (18 A/phase), the core volume of the PMCI is reduced to 51.9% and the core weight is reduced to 51.2%. In addition, the PMCI achieves ∼76.3% core size and ∼73.4% core weight reductions compared to two separate single-phase PIs with the same steady-state inductance and similar saturation current (∼22 A) due to the dual flux cancelation effect from the coupling and PM- realized by the presented PMCI structure.
Autors: Zhigang Dang;Jaber A. Abu Qahouq;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Mar 2017, volume: 64, issue:3, pages: 1971 - 1981
Publisher: IEEE
 
» Person Reidentification Using Deep Convnets With Multitask Learning
Abstract:
Person reidentification involves recognizing a person across nonoverlapping camera views, with different pose, illumination, and camera characteristics. We propose to tackle this problem by training a deep convolutional network to represent a person’s appearance as a low-dimensional feature vector that is invariant to common appearance variations encountered in the reidentification problem. Specifically, a Siamese network architecture is used to train a feature extraction network using pairs of similar and dissimilar images. We show that the use of a novel multitask learning objective is crucial for regularizing the network parameters in order to prevent overfitting due to the small size of the training data set. We complement the verification task, which is at the heart of reidentification, by training the network to jointly perform verification and identification and to recognize attributes related to the clothing and pose of the person in each image. In addition, we show that our proposed approach performs well even in the challenging cross-data set scenario, which may better reflect real-world expected performance.
Autors: Niall McLaughlin;Jesus Martinez del Rincon;Paul C. Miller;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Mar 2017, volume: 27, issue:3, pages: 525 - 539
Publisher: IEEE
 
» Person Reidentification Using Multiple Egocentric Views
Abstract:
Development of a robust and scalable multicamera surveillance system is the need of the hour to ensure public safety and security. Being able to reidentify and track one or more targets over multiple nonoverlapping camera field of views in a crowded environment remains an important and challenging problem because of occlusions, large change in the viewpoints, and illumination across cameras. However, the rise of wearable imaging devices has led to new avenues in solving the reidentification (re-id) problem. Unlike static cameras, where the views are often restricted or low resolution and occlusions are common scenarios, egocentric/first person views (FPVs) mostly get zoomed in, unoccluded face images. In this paper, we present a person re-id framework designed for a network of multiple wearable devices. The proposed framework builds on commonly used facial feature extraction and similarity computation methods between camera pairs and utilizes a data association method to yield globally optimal and consistent re-id results with much improved accuracy. Moreover, to ensure its utility in practical applications where a large amount of observations are available every instant, an online scheme is proposed as a direct extension of the batch method. This can dynamically associate new observations to already observed and labeled targets in an iterative fashion. We tested both the offline and online methods on realistic FPV video databases, collected using multiple wearable cameras in a complex office environment and observed large improvements in performance when compared with the state of the arts.
Autors: Anirban Chakraborty;Bappaditya Mandal;Junsong Yuan;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Mar 2017, volume: 27, issue:3, pages: 484 - 498
Publisher: IEEE
 
» Personalized Radiotherapy Planning Based on a Computational Tumor Growth Model
Abstract:
In this article, we propose a proof of concept for the automatic planning of personalized radiotherapy for brain tumors. A computational model of glioblastoma growth is combined with an exponential cell survival model to describe the effect of radiotherapy. The model is personalized to the magnetic resonance images (MRIs) of a given patient. It takes into account the uncertainty in the model parameters, together with the uncertainty in the MRI segmentations. The computed probability distribution over tumor cell densities, together with the cell survival model, is used to define the prescription dose distribution, which is the basis for subsequent Intensity Modulated Radiation Therapy (IMRT) planning. Depending on the clinical data available, we compare three different scenarios to personalize the model. First, we consider a single MRI acquisition before therapy, as it would usually be the case in clinical routine. Second, we use two MRI acquisitions at two distinct time points in order to personalize the model and plan radiotherapy. Third, we include the uncertainty in the segmentation process. We present the application of our approach on two patients diagnosed with high grade glioma. We introduce two methods to derive the radiotherapy prescription dose distribution, which are based on minimizing integral tumor cell survival using the maximum a posteriori or the expected tumor cell density. We show how our method allows the user to compute a patient specific radiotherapy planning conformal to the tumor infiltration. We further present extensions of the method in order to spare adjacent organs at risk by re-distributing the dose. The presented approach and its proof of concept may help in the future to better target the tumor and spare organs at risk.
Autors: Matthieu Lê;Hervé Delingette;Jayashree Kalpathy-Cramer;Elizabeth R. Gerstner;Tracy Batchelor;Jan Unkelbach;Nicholas Ayache;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Mar 2017, volume: 36, issue:3, pages: 815 - 825
Publisher: IEEE
 
» Perspective Paper—Can AC Computing Be an Alternative for Wirelessly Powered IoT Devices?
Abstract:
An alternative computing paradigm is explored in this letter with application to wirelessly powered Internet of Things (IoT) devices. Contrary to existing methods that rely on DC computing, the wirelessly harvested AC power is directly used for computation by leveraging charge-recycling theory. The proposed approach has the potential to significantly reduce the energy cost, one of the primary barriers that slows down the global scalability of IoT devices. This opportunity and related challenges are investigated in this letter to provide guidelines for future research in the field.
Autors: Tutu Wan;Yasha Karimi;Milutin Stanaćević;Emre Salman;
Appeared in: IEEE Embedded Systems Letters
Publication date: Mar 2017, volume: 9, issue:1, pages: 13 - 16
Publisher: IEEE
 
» PES Fellows: Congratulations to the Class of 2017 [Awards]
Abstract:
Presents PES society members who were elevated to the status of IEEE Fellow in 2017.
Autors: Venkat Sharma Kolluri;
Appeared in: IEEE Power and Energy Magazine
Publication date: Mar 2017, volume: 15, issue:2, pages: 90 - 91
Publisher: IEEE
 
» Petri-Net Controller Synthesis for Partially Controllable and Observable Discrete Event Systems
Abstract:
To enforce linear constraints on Petri nets that are partially controllable and observable, this work proposes an approach based on constraint transformation. First, a state-space equation of a Petri net control system based on event feedback is obtained by expressing a control action as a matrix, and the optimal control policy is designed. However, this policy needs to solve a nonlinear program on line. Second, pre-transition-gain-transformation is proposed to equivalently transform a constraint into a disjunction of new ones for an uncontrollable transition, and, similarly, post-transition-gain-transformation to transform a constraint into a disjunction of new ones for an unobservable transition. An algorithm is then given to transform a constraint into a disjunction of admissible ones, and, consequently, an efficient policy, which may not be optimal, can be designed. Third, in order to guarantee that the policy be both efficient and optimal, a dynamic linear constraint is introduced. Further, observing-transformation is proposed to simplify a dynamic constraint for an unobservable transition, and an algorithm is given to equivalently transform a class of linear constraints into admissible dynamic ones. As a result, an optimal controller requiring little online computation can be designed accordingly for some class of Petri nets. Finally, a maze system is used to illustrate the theoretical results.
Autors: JiLiang Luo;MengChu Zhou;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Mar 2017, volume: 62, issue:3, pages: 1301 - 1313
Publisher: IEEE
 
» Phase Inverters Based on Substrate Integrated Waveguide
Abstract:
Phase inverters (PI) suit a wide range of applications for microwave systems. There are lots of reports about PIs based on microstrip or coplanar waveguide, some of which obtain simple configurations and wide bandwidths. However, there are few reports about PI based on substrate integrated waveguide (SIW). Inspired by a microstrip PI constituted by an interdigital slot and metallic vias, a new SIW PI is proposed for the first time. Furthermore, a phase shifter is inserted to the SIW PI in order to compensate the signal delay. Both prototype and compensation-type PIs represent good transmission performance with return loss better than 10 dB in 8.3–13 GHz. The bandwidth of the prototype can reach 47.6% with phase deviation less than 10° compared with 38-mm transmission line, which shows more excellent performance.
Autors: Xiong Zou;Fang-Zhi Geng;Yong Li;Yi Leng;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Mar 2017, volume: 27, issue:3, pages: 227 - 229
Publisher: IEEE
 
» Physical-Perceptual Correspondence for Dynamic Thermal Stimulation
Abstract:
Thermal displays have been applied in various haptic applications, from material simulation to interpersonal communication; however, there is insufficient knowledge about the temporal processing in human thermal sense to provide a knowledge basis for thermal display design. In this study, we investigated the physical-perceptual correspondence for dynamic thermal stimulation to shed a light on the temporal processing of human thermal sense. In the experiments, participants reported subjective timings of the temperature onset and temperature peak of continuous temperature changes applied to the thenar eminence. We found that the physical-perceptual correspondence was not consistent for warm and cold stimulations. For warm stimulation, the subjective experience always came after the corresponding physical event. On the other hand, for cold stimulation, while the subjective onset always lagged the physical onset, the subjective temperature peak preceded the physical temperature peak. We analyzed these results in the framework of linear systems theory. The results suggest that the senses of warmth and cold have distinct temporal filtering properties, with the sense of cold being more transient than the sense of warmth. These findings advance our knowledge regarding temporal processing in human thermal sense and serve as a basis for thermal display design.
Autors: Hsin-Ni Ho;Katsunari Sato;Scinob Kuroki;Junji Watanabe;Takashi Maeno;Shin'ya Nishida;
Appeared in: IEEE Transactions on Haptics
Publication date: Mar 2017, volume: 10, issue:1, pages: 84 - 93
Publisher: IEEE
 
» Physics-Based Hydraulic Turbine Model for System Dynamic Studies
Abstract:
A one-dimensional numerical model of a Francis turbine hydropower plant for dynamic response studies is presented with an alternate representation of the turbine unit component. The conventional, simplified representation of the hydraulic turbine is replaced by a consideration of the conservation of angular momentum using inlet and outlet velocity vectors calculated based on effective turbine geometry. Specific energy loss components associated with off-design conditions such as runner blade inlet incidence loss and draft tube residual swirl flow loss are determined. Estimates for mechanical frictional losses and churning losses are calculated to ensure accurate simulation across the entire turbine operating range. The resulting model therefore takes into consideration real sources of major loss, eliminating the use of ambiguous correction factors, while remaining equally simple to implement into current power system models. The new turbine formulation is validated against transient test data from a 119 MW Francis turbine unit, while simulations based on two existing conventional models are included for comparison.
Autors: Dean R. Giosio;Alan D. Henderson;Jessica M. Walker;Paul A. Brandner;
Appeared in: IEEE Transactions on Power Systems
Publication date: Mar 2017, volume: 32, issue:2, pages: 1161 - 1168
Publisher: IEEE
 
» Piecewise Nonlinear Frequency Modulation Waveform for MIMO Radar
Abstract:
We propose a piecewise nonlinear frequency modulation (PNLFM) waveform for a multiple-input multiple-output (MIMO) radar. Each subpulse in the waveform set is divided into three segments. The first and the third segments are linear frequency modulation (LFM) signals, whereas the second segment is a nonlinear frequency modulation (NLFM) signal. The bandwidths and durations of subpulses are the same, whereas they can be different for each segment in the subpulse. In addition, the nonlinear time–frequency function of the second segment is controlled to improve the range and Doppler sidelobe suppression. A genetic algorithm is implemented to optimize the performance by maximally suppressing the autocorrelation sidelobe and cross correlation in range, Doppler, and angle. The MIMO radar performance is demonstrated via computation of the ambiguity function, autocorrelation function, and cross-correlation function. Numerical results are presented to show waveform properties and to compare with some existing MIMO radar waveforms. The proposed PNLFM waveform has low autocorrelation sidelobes and low cross correlation in range and Doppler, which sits at a level determined largely by the chosen time–bandwidth product.
Autors: Caicai Gao;Kah Chan Teh;Aifei Liu;
Appeared in: IEEE Journal of Selected Topics in Signal Processing
Publication date: Mar 2017, volume: 11, issue:2, pages: 379 - 390
Publisher: IEEE
 
» Piezoresistive Behavior of MWCNT–UHMWPE Composite for Compressive Stress Sensing Applications
Abstract:
With increasing interest from research laboratories and industry in instrumented knee replacement arthroplasties, we aim to fabricate a novel stress sensor that can be embedded into the tibial knee bearing with the least alteration to the mechanical properties of the bearings. Therefore, the most commonly used material for tibial inserts, ultrahigh molecular weight polyethylene (UHMWPE), was used as the matrix for the sensor. Multiwalled carbon nanotubes were added as nano fillers to transform the insulating UHMWPE into an electrically conducting nano-composite. The electrical percolation threshold of the nanocomposites was calculated to be 0.34 wt%. The samples showed a linear current–voltage response when excited with a sine-wave electrical current source. Under quasi-static compressive loading, samples resistances showed a decreasing trend with increasing stress. The 0.3 wt% sample showed a higher stress coefficient, but also a lower degree of linearity compared to the 0.5 wt% samples, owing to the significant change in the tunneling resistance of carbon nanotube networks under stress. Reasonably repeatable piezoresistive response between loading cycles (with coefficient of variation less than 5%) was also observed during short cyclic compression sequences.
Autors: Quyen Do;Sean O’Byrne;Mei Liu;Liangchi Zhang;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Mar 2017, volume: 16, issue:2, pages: 265 - 273
Publisher: IEEE
 
» Pilot-Scale Exhaust Gas Treatment for a Glass Manufacturing System Using a Plasma Combined Semi-dry Chemical Process
Abstract:
A pilot-scale simultaneous removal of and , as a nonthermal plasma and chemical hybrid process (PCHP), is carried out on combustion exhaust gas in a glass manufacturing system. The PCHP is implemented in an actual semi-dry-type exhaust gas treatment system. The exhaust gas (12 700 m3N/h) is produced by the combustion of fossil fuels and contains both (160 ppm) and (150 ppm). In PCHP, is oxidized to water-soluble through a plasma process using ozone. is then produced as a byproduct in a desulfurizing process using a solution of NaOH. The generated is then reduced to and using an solution, followed by the dried particles being removed in a semi-dry reactor by a dry-type electrostatic precipitator. Our findings show the molar ratio of to the injected ozone to be more than 0.75. and removal efficiencies of 28% and 63% are obtained. Further, the paper discusses de- by the use of a bag filter (BF) for the injection of the at the BF inlet. Due to the effect of ozone and , removal efficiency is increased by up to 45%. Our results show that higher de- and de- efficiencies are obtained by maintaining a local exhaust gas temperature of less than 150 °C. Through this experiment, it is confirmed that this simultaneous treatment of and using semi-dry-type PCHP is highly effective and promising for exhaust gas treatment in glass manufacturing.
Autors: Hashira Yamamoto;Tomoyuki Kuroki;Hidekatsu Fujishima;Yuri Yamamoto;Kouta Yoshida;Masaaki Okubo;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Mar 2017, volume: 53, issue:2, pages: 1416 - 1423
Publisher: IEEE
 
» Placement Optimization of UAV-Mounted Mobile Base Stations
Abstract:
In terrestrial communication networks without fixed infrastructure, unmanned aerial vehicle-mounted mobile base stations (MBSs) provide an efficient solution to achieve wireless connectivity. This letter aims to minimize the number of MBSs needed to provide wireless coverage for a group of distributed ground terminals (GTs), ensuring that each GT is within the communication range of at least one MBS. We propose a polynomial-time algorithm with successive MBS placement, where the MBSs are placed sequentially starting on the area perimeter of the uncovered GTs along a spiral path toward the center, until all GTs are covered. Numerical results show that the proposed algorithm performs favorably compared with other schemes in terms of the number of required MBSs as well as time complexity.
Autors: Jiangbin Lyu;Yong Zeng;Rui Zhang;Teng Joon Lim;
Appeared in: IEEE Communications Letters
Publication date: Mar 2017, volume: 21, issue:3, pages: 604 - 607
Publisher: IEEE
 
» Planar Miniaturized Balanced-to-Single-Ended Power Divider Based on Composite Left- and Right-Handed Transmission Lines
Abstract:
A planar asymmetrical miniaturized circuit based on composite left- and right-handed transmission lines (CLRHTLs) is proposed to design a new balanced-to-single-ended (BTSE) power divider (PD) in this letter. The CLRHTLs are used to realize circuit miniaturization and positive-phase response. Conversion between the mixed-mode scattering parameters and the standard scattering parameters, and circuit analytical methods are discussed to realize the equal power division in phase from one differential input to two SE outputs. To verify the correctness of the proposed theory, a practical BTSE PD, which operates at 0.95 GHz, is designed and fabricated. The measured relative bandwidth is 26.3%, and the final circuit size is only .
Autors: Weiwei Zhang;Xiaochuan Shen;Yongle Wu;Yuanan Liu;Abul Hasan;Fadhel M. Ghannouchi;Yulong Zhao;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Mar 2017, volume: 27, issue:3, pages: 242 - 244
Publisher: IEEE
 
» Planar Triorthogonal Diversity Slot Antenna
Abstract:
This communication proposes an easily manufacturable multifunction multiport planar slot antenna with triorthogonal pattern diversity. Distinct radiation patterns are emitted via a common square radiative slot by exploiting three orthogonal modes. These slot modes consist of a magnetic current loop mode with an omnidirectional linearly polarized (OLP) radiation pattern, and two degenerated linear slot modes radiating broadside with orthogonal linear polarizations (LPs). The triorthogonal patterns are obtained in an overlapping frequency band, and the mutual coupling between the ports is minimized through a differential feeding arrangement. This new concept of multiport diversity slot antenna is validated experimentally at a frequency of 5.9 GHz, successfully demonstrating the operation modalities of OLP and LP radiation patterns. A minimum triorthogonal overlapping impedance bandwidth of 2.3% is measured with interport coupling below −35 dB. The proposed antenna could be used as a pattern and polarization diversity antenna, where additionally, a linear combination of the primary triorthogonal patterns can be exploited to further enhance flexibility in pattern generation.
Autors: Nicholas P. Lawrence;Christophe Fumeaux;Derek Abbott;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Mar 2017, volume: 65, issue:3, pages: 1416 - 1421
Publisher: IEEE
 
» Planning of Ultra-Dense Wireless Networks
Abstract:
Fifth generation (5G) wireless networks adopt the deployment of ultra-dense small cells for efficient slicing of radio resources. This conceptual change in network structure aims to meet the rapid increase in mobile data traffic and connected devices. However, limited free spectrum and dynamic assignment of resources are main concerns when considering the cognitive small cells solution. Therefore, there is a need to map traffic patterns with the number of cognitive small cells to provide an optimized network architecture operating with adequate spectrum resources. This article investigates the case when network densification exceeds the radio resource capacity, causing a large scale overlapping in cell coverage area and used channels. Taking into consideration cognitive network performance characteristics, we identify two spectrum coexistence frameworks, Space Filling and Time Filling, to improve spectrum utilization and scalability for moderately large networks. Simulations show that there is a turning point when network performance starts to decline as the number of cognitive small cells exceeds the shared resources in a site area, subject to a certain load profile. This optimization of network structure, based on spectrum transmission opportunities, brings about a new topic for operators and research communities considering small cells operating in the unlicensed band.
Autors: Anwer Al-Dulaimi;Saba Al-Rubaye;John Cosmas;Alagan Anpalagan;
Appeared in: IEEE Network
Publication date: Mar 2017, volume: 31, issue:2, pages: 90 - 96
Publisher: IEEE
 
» Plasma Actuator Performance Driven by Dual-Power Supply Voltage—AC High Voltage Superimposed With Pulse Bias Voltage
Abstract:
Many studies have demonstrated the utility of surface dielectric barrier discharge (SDBD) plasma actuators driven by different voltage waveforms for airflow control. In this paper, a new dual-power supply voltage consisting of ac high voltage with a superimposed positive or negative pulse bias voltage is applied to a two-electrode structure SDBD actuator to compare the actuator performance with that driven by a single ac voltage waveform. The ionic wind velocity, the thrust force, and the schlieren visualization images are studied under three types of voltage waveforms: single ac voltage, ac voltage superimposed with a positive pulse bias voltage (ACPP), and ac voltage superimposed with a negative pulse bias voltage (ACNP). The influences of different pulse parameters including pulse voltage, pulse repetition frequency (PRF), and pulsewidth on the actuator performance are studied in detail. Experimental results show that pulse voltage and PRF have more notable influence on the actuator performance when the actuator is driven by ACPP, while the pulsewidth has little effect on the actuator performance. In contrast, the actuator performance is little changed when the actuator is driven by ACNP. The positive and negative pulse discharges have different effects on the actuator performance, the reason is positive pulse discharge increases the discharge of glow-like region while negative pulse discharge increases the discharge of streamer region in the following ac cycle. The schlieren images further indicate pulse discharge exerts its effects on the SDBD actuator performance by affecting the electric field of ac discharge.
Autors: Xiao-Hua Qi;Liang Yang;Hui-Jie Yan;Ying Jin;Chun-Sheng Ren;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Mar 2017, volume: 45, issue:3, pages: 412 - 422
Publisher: IEEE
 
» Plasmon-Sensitized Optoelectronic Properties of Au Nanoparticle-Assisted Vertically Aligned TiO2 Nanowires by GLAD Technique
Abstract:
In this paper, the glancing angle deposition technique is used to fabricate Au nanoparticle-assisted vertically aligned TiO2 nanowires (Au-NP-TiO2-NW) on glass and Si substrates. The effect of annealing on the plasmonic resonance and optical properties of Au-NP-TiO2-NW are investigated by UV-visible absorption and photoluminescence spectroscopy. The field emission gun-scanning electron microscopy with energy dispersive spectroscopy analysis manifests the successful growth of Au-NP-TiO2-NW on Si substrate with the presence of Au, Titanium (Ti), Oxygen (O), and Silicon (Si) in the sample. The transmission electron microscope and X-ray diffraction analysis reveal the polycrystalline nature of the anatase TiO2-NW and Au-NPs with improved crystal quality after annealing. The rectifying behavior of Au-NP-TiO2-NW/Si-based photodetector device under forward bias in dark condition demonstrates the formation of p-n junction at the interface of Au-NP-TiO2-NW and p-Si. The photocurrent and dark current density recorded for the device at 4 V are and A/cm2, respectively. However, it is interesting to observe that an average ~60 folds photocurrent as compared with dark current with an excellent response time under the on/off switching of white light upon the device at −3 V, which confirms potential application in optoelectronics.
Autors: Biraj Shougaijam;Chitralekha Ngangbam;Trupti Ranjan Lenka;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Mar 2017, volume: 64, issue:3, pages: 1127 - 1133
Publisher: IEEE
 
» PMNDN: Proxy Based Mobility Support Approach in Mobile NDN Environment
Abstract:
In this paper, we study the source mobility problem that exists in the current named data networking (NDN) architecture and propose a proxy-based mobility support approach named PMNDN to overcome the problem. PMNDN proposes using a proxy to efficiently manage source mobility. Besides, functionalities of the NDN access routers are extended to track the mobility status of a source and signal Proxy about a handoff event. With this design, a mobile source does not need to participate in handoff signaling which reduces the consumption of limited wireless bandwidth. PMNDN also features an ID that is structurally similar to the content name so that routing scalability of NDN architecture is maintained and addressing efficiency of Interest packets is improved. We illustrate the performance advantages of our proposed solution by comparing the handoff performance of the mobility support approaches with that in NDN architecture and current Internet architecture via analytical and simulation investigation. We show that PMNDN offers lower handoff cost, shorter handoff latency, and less packet losses during the handoff process.
Autors: Deyun Gao;Ying Rao;Chuan Heng Foh;Hongke Zhang;Athanasios V. Vasilakos;
Appeared in: IEEE Transactions on Network and Service Management
Publication date: Mar 2017, volume: 14, issue:1, pages: 191 - 203
Publisher: IEEE
 
» Polarization Reconfigurable Circular Patch Antenna With a C-Shaped
Abstract:
Polarization reconfigurable circular patch antenna with a C-shaped slot is proposed in this communication. It is demonstrated that by introducing a reconfigurable C-shaped slot in a circular patch antenna, the polarization of the radiation of the antenna, operating either in a linearly or circularly polarized mode, can be switched effectively. It is switched between vertical and horizontal polarizations for a linearly polarized mode and switched between left hand circularly polarization and right hand circularly polarization for a circularly polarized mode. The polarization reconfigurable characteristic is realized by controlling the states of the two switching diodes mounted over a concentric circular slot incorporated on the patch, so as to vary the orientation of the C-slot. Prototypes of both linear polarization and circular polarization designs were developed and the performances were validated against measurements. Both antennas exhibit over 20% impedance bandwidth (standing wave ratio (SWR) < 2) and perform broadside radiation over the operating band. The 3-dB axial ratio bandwidth for the circularly polarized case is 4%.
Autors: Ka Ming Mak;Hau Wah Lai;Kwai Man Luk;Kin Lun Ho;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Mar 2017, volume: 65, issue:3, pages: 1388 - 1392
Publisher: IEEE
 
» Pole-Converging Intrastage Bandwidth Extension Technique for Wideband Amplifiers
Abstract:
To overcome limitations on bandwidth extension in conventional design techniques, a novel pole-converging technique with transformer feedback for intrastage bandwidth extension is proposed and analyzed in this paper. For verification, a three-stage cascode low-noise amplifier (LNA) based on the pole converging and negative drain–source transformer feedback is designed and implemented in a 65-nm CMOS technology. Consuming 27 mW dc power from a 1.8 V supply, the fabricated prototype exhibits peak power gain of 18.5 dB, minimum noise figure of 5.5 dB, 3-dB bandwidth of 30 GHz, and fractional bandwidth of 38.7%. The bandwidth of the three-stage cascode LNA is significantly extended without increasing power consumption and die size.
Autors: Guangyin Feng;Chirn Chye Boon;Fanyi Meng;Xiang Yi;Kaituo Yang;Chenyang Li;Howard C. Luong;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Mar 2017, volume: 52, issue:3, pages: 769 - 780
Publisher: IEEE
 
» Pole-Zero Approach to Analyze and Model the Kink in Gain-Frequency Plot of GaN HEMTs
Abstract:
In this letter, we present a novel approach toward understanding the Kink effect (KE) in the bode plot of short circuit current gain () observed for microwave transistors, particularly gallium nitride (GaN) HEMTs. We ascribe the origin of the KE to the presence of a pair of complex conjugate poles at the frequency of interest, introduced due to the extrinsic parasitic inductances and their interaction with the device intrinsic elements, such as the capacitances and transconductance, and develop simplified mathematical expressions that govern the behavior of the kink. We also present a physics-based compact model that is capable of capturing the KE and extensively validate the model against measured data for a GaN device under multibias conditions, thereby advocating the strong physical background of the model. We conclude by demonstrating the impact of various elements of the small signal model on the kink based on the developed mathematical hypothesis for KE.
Autors: Sheikh Aamir Ahsan;Sudip Ghosh;Sourabh Khandelwal;Yogesh Singh Chauhan;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Mar 2017, volume: 27, issue:3, pages: 266 - 268
Publisher: IEEE
 
» Poly(p-xylylene) Silver Nanocomposites: Optical, Radiative, and Structural Properties
Abstract:
We perform a detailed investigation of coatings made of poly(p-xylylene) nanocomposites with embedded silver nanoparticles of sizes up to 12 nm and concentration up to 10.5 vol. %. We study their microstructure, mechanical, optical, and radiative characteristics. We reveal certain correlations between structural peculiarities and optical, as well as radiative properties. These correlations are due to fluctuations in distribution of nanoparticles in a polymer matrix and also due to the peculiarities of nanoparticles size distribution. We calculated optical dispersion coefficients for nanocomposites with different silver content. It was shown the refractive index ( n) and extinction coefficient (k) is strongly dependent on the silver content and change within the 1.4–2.4 for n and 0–0.6 for the k. It is argued that poly(p-xylylene)silver nanocomposites can be used to construct multilayer coatings with required optical constant and conformal to any complex morphology.
Autors: Konstantin N. Afanasev;Irina A. Boginskaya;Alexandr V. Dorofeenko;Alexey V. Gysev;Karen A. Mailyan;Andrey V. Pebalk;Vladimir N. Chvalyn;Sergey A. Ozerin;Marina V. Sedova;Ilya A. Rodionov;Walter V. Pogosov;Ilya A. Ryzhikov;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Mar 2017, volume: 16, issue:2, pages: 274 - 280
Publisher: IEEE
 
» Pooling-Based Quantitative Approach to Evaluating Binarization Algorithms
Abstract:
To quantitatively evaluate an image binarization algorithm when the ground-truth binary images are unavailable, the authors propose a quantitative evaluation approach based on pooling. First, the binarized images of a sample image from the image dataset (binarized by 27 commonly used binarization algorithms) are put into a pool. Then the pseudo ground truth--two weight matrices of foreground and background points--is produced using the 27 binarized images. Finally, for the image binarization algorithm to be evaluated, a quantitative evaluation operator is generated from the two weight matrices in the pool. The authors ran experiments using two image datasets, and the results show that this quantitative evaluation approach is effective and practical.
Autors: Maofu Liu;Ya Liu;Zhenguang Liu;Huijun Hu;Wei Fang;
Appeared in: IEEE Multimedia
Publication date: Mar 2017, volume: 24, issue:1, pages: 86 - 92
Publisher: IEEE
 
» Portable System for Practical Permittivity Measurements Improved by Homomorphic Deconvolution
Abstract:
This paper presents a versatile low-cost procedure for complex permittivity measurements of liquids from 400 MHz to 5 GHz. Our procedure uses handheld instrumentation and custom software for data acquisition and postprocessing. The purpose is to replace the benchtop vector network analyzer (VNA) generally used in such applications with a portable and cheaper handheld spectrum analyzer used in the VNA mode. Postprocessing software based on homomorphic deconvolution is used to remove possible inaccuracies in the permittivity spectra coming from the reduced performance of the handheld VNA with respect to benchtop models. Our measurements are evaluated by comparison with those of the National Physical Laboratory (NPL). The results of the real and imaginary parts of the permittivity spectra of two well characterized organic compounds, ethanediol and 2-propanol, are in very good agreement with the NPL reference standards, showing a relative root-mean-square error (RRMSE) always less than 5%. Low values of the RRMSE, together with an expanded uncertainty less than 3%, ensure that our permittivity measurements are repeatable and accurate. Thanks to its versatility, portability, and at least half of the cost of commercial models, our system is suitable for on-site measurements in different applications, including food quality monitoring and control of medical treatments and biological procedures.
Autors: Caterina Merla;Alessandra Paffi;Francesca Apollonio;Simone Orcioni;Micaela Liberti;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Mar 2017, volume: 66, issue:3, pages: 514 - 521
Publisher: IEEE
 
» Potential of Jatropha curcas oil as a dielectric fluid for power transformers
Abstract:
A dielectric liquid provides two main functions in power transformers: an insulant and a cooling medium. Mineral oil, largely due to its availability and low cost, has predominantly been used in power transformers for more than 100 years [1]-[3]. However, mainly due to its low biodegradability, a spill contaminating soil and water can be detrimental to the environment [4]. This shortcoming has prompted researchers to focus on safety, biodegradability, and renewability of dielectric fluids. The dielectric fluids based on vegetable oils (natural esters) are an innovative alternative since they have shown comparable, and sometimes better, dielectric, physical, and chemical properties to mineral insulating oils [5]-[8].
Autors: N. Beltrán;E. Palacios;G. Blass;
Appeared in: IEEE Electrical Insulation Magazine
Publication date: Mar 2017, volume: 33, issue:2, pages: 8 - 15
Publisher: IEEE
 
» Power Allocation for OFDM Wireless Network Localization Under Expectation and Robustness Constraints
Abstract:
In location-aware wireless networks, mobile nodes (agents) can obtain their positions using range measurements to other nodes with known positions (anchors). Optimal subcarrier power allocation at the anchors reduces positioning error and improves network lifetime and throughput. We present an optimization framework for subcarrier power allocations in network localization with the imperfect knowledge of network parameters based on the fundamental statistical limits. Power allocations with expectation and robustness constraints are obtained using semidefinite optimization problems in non-iterative and iterative forms with both unicast and multicast transmissions. Results show that the allocations provide more accurate localization than non-robust designs under channel and agents positions uncertainty.
Autors: Arash Shahmansoori;Gonzalo Seco-Granados;Henk Wymeersch;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Mar 2017, volume: 16, issue:3, pages: 2027 - 2038
Publisher: IEEE
 
» Power Flow Management of a Grid Tied PV-Battery System for Electric Vehicles Charging
Abstract:
The prospective spread of electric vehicles (EV) and plug-in hybrid EV raises the need for fast charging rates. High required charging rates lead to high power demands, which may not be supported by the grid. In this paper, an optimal power flow technique of a PV-battery powered fast EV charging station is presented to continuously minimize the operation cost. The objective is to help the penetration of PV-battery systems into the grid and to support the growing need of fast EV charging. An optimization problem is formulated along with the required constraints and the operating cost function is chosen as a combination of electricity grid prices and the battery degradation cost. In the first stage of the proposed optimization procedure, an offline particle swarm optimization (PSO) is performed as a prediction layer. In the second stage, dynamic programming (DP) is performed as an online reactive management layer. Forecasted system data is utilized in both stages to find the optimal power management solution. In the reactive management layer, the outputs of the PSO are used to limit the available state trajectories used in the DP and, accordingly, improve the system computation time and efficiency. Online error compensation is implemented into the DP and fed back to the prediction layer for necessary prediction adjustments. Simulation and 1 kW prototype experimental results are successfully implemented to validate the system effectiveness and to demonstrate the benefits of using a hybrid grid tied system of PV-battery for fast EVs charging stations.
Autors: Mohamed O. Badawy;Yilmaz Sozer;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Mar 2017, volume: 53, issue:2, pages: 1347 - 1357
Publisher: IEEE
 
» Power Performance Verification of a Wind Turbine by using the Wilcoxon Signed-Rank Test
Abstract:
In this letter, nonparametric statistical inference is applied to designing a simple, inexpensive method of verifying the power performance of a wind turbine. The proposed method uses the data collected by the Supervisory Control and Data Acquisition (SCADA) system and the guaranteed power curve of the turbine, and it says whether the power performance of a wind turbine differed significantly from what would be expected.
Autors: Wilmar Hernandez;Jorge L. Maldonado-Correa;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Mar 2017, volume: 32, issue:1, pages: 394 - 396
Publisher: IEEE
 
» Power-Aware Maximization of Ergodic Capacity in D2D Underlay Networks
Abstract:
Device-to-device (D2D) underlay networks enable high data rates and low end-to-end delay and improve spectral/energy efficiency and offload cellular traffic. However, D2D communication also results in interference between CUs and D2D terminals, negatively impacting capacity. Is there a critical set of system parameters (density of D2D users (DUs), cellular base stations (BSs), transmit power, etc.) that can ensure that the benefits of D2D underlay operation can outweigh its drawbacks? We seek to address this fundamental question in the context of the tradeoff between ergodic capacity and power consumption. Toward this end, we first quantify the ergodic capacity metric for a realistic network where D2D pairs are spaced randomly and experience Rician fading. Based on a stochastic-geometry-based network model, we derive, for the first time, closed-form results for ergodic capacity of both cellular users (CUs) and DUs. Second, we identify the D2D user density and transmit power that maximizes the ergodic capacity of the network. Specifically, a two-stage scheme is proposed to optimize ergodic capacity while minimizing overall power consumption. The results from this analysis provide a framework to uncover desirable system design parameters that offer the best gains in terms of capacity.
Autors: Chang Liu;Balasubramaniam Natarajan;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Mar 2017, volume: 66, issue:3, pages: 2727 - 2739
Publisher: IEEE
 
» Power-Gated 9T SRAM Cell for Low-Energy Operation
Abstract:
This brief proposes a novel power-gated 9T (PG9T) static random access memory (SRAM) cell that uses a read-decoupled access buffer and power-gating transistors to execute reliable read and write operations. The proposed 9T SRAM cell uses bit interleaving to achieve soft error immunity and utilizes a column-based virtual signal to eliminate unnecessary bitline discharges in the unselected columns, thereby reducing the energy consumption. In a 22-nm FinFET technology, the proposed PG9T SRAM cell has a minimum operating voltage of 0.32 V while achieving the read stability yield. Compared with the previously proposed 9T SRAM cell, the proposed cell consumes 45% and 17% less energy per read and write operation, respectively, at the minimum operating voltage, and has a 12% smaller bit cell area.
Autors: Tae Woo Oh;Hanwool Jeong;Kyoman Kang;Juhyun Park;Younghwi Yang;Seong-Ook Jung;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Mar 2017, volume: 25, issue:3, pages: 1183 - 1187
Publisher: IEEE
 
» Practical Multicriteria Urban Bicycle Routing
Abstract:
Increasing the adoption of cycling is crucial for achieving more sustainable urban mobility. Navigating larger cities on a bike is, however, often challenging due to the cities' fragmented cycling infrastructure and/or complex terrain topology. Cyclists would thus benefit from intelligent route planning that would help them discover routes that best suit their transport needs and preferences. Because of the many factors cyclists consider in deciding their routes, employing a multicriteria route search is vital for properly accounting for cyclists' route-choice criteria. A direct application of optimal multicriteria route search algorithms is, however, not feasible due to their prohibitive computational complexity. In this paper, we formalize a multicriteria bicycle routing problem and propose several heuristics for speeding up the multicriteria route search. We evaluate our method on a real-world cycleway network and show that speedups of up to four orders of magnitude over the standard multicriteria label-setting algorithm are possible with a reasonable loss of solution quality. Our results make it possible to practically deploy bicycle route planners capable of producing diverse high-quality route suggestions respecting multiple real-world route-choice criteria.
Autors: Jan Hrnčíř;Pavol Žilecký;Qing Song;Michal Jakob;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Mar 2017, volume: 18, issue:3, pages: 493 - 504
Publisher: IEEE
 
» Predicting Student Performance from LMS Data: A Comparison of 17 Blended Courses Using Moodle LMS
Abstract:
With the adoption of Learning Management Systems (LMSs) in educational institutions, a lot of data has become available describing students’ online behavior. Many researchers have used these data to predict student performance. This has led to a rather diverse set of findings, possibly related to the diversity in courses and predictor variables extracted from the LMS, which makes it hard to draw general conclusions about the mechanisms underlying student performance. We first provide an overview of the theoretical arguments used in learning analytics research and the typical predictors that have been used in recent studies. We then analyze 17 blended courses with 4,989 students in a single institution using Moodle LMS, in which we predict student performance from LMS predictor variables as used in the literature and from in-between assessment grades, using both multi-level and standard regressions. Our analyses show that the results of predictive modeling, notwithstanding the fact that they are collected within a single institution, strongly vary across courses. Thus, the portability of the prediction models across courses is low. In addition, we show that for the purpose of early intervention or when in-between assessment grades are taken into account, LMS data are of little (additional) value. We outline the implications of our findings and emphasize the need to include more specific theoretical argumentation and additional data sources other than just the LMS data.
Autors: Rianne Conijn;Chris Snijders;Ad Kleingeld;Uwe Matzat;
Appeared in: IEEE Transactions on Learning Technologies
Publication date: Mar 2017, volume: 10, issue:1, pages: 17 - 29
Publisher: IEEE
 
» Predicting Subharmonic Oscillation of Voltage-Mode Switching Converters Using a Circuit-Oriented Geometrical Approach
Abstract:
A circuit-oriented geometrical approach in predicting subharmonic oscillation (SHO) of voltage-mode switching converters is presented. It is based on a straightforward graphical analysis of the operation of the converter without using advanced mathematical techniques. It is shown that the slope of the output of the compensator at the trip point is an important factor in determining the onset of SHO. The critical condition of SHO of the buck converter working in continuous conduction mode (CCM) is derived and expressed in terms of circuit parameters that serve as the design guideline for avoiding SHO. The proposed approach is applied to analyze three schemes, namely, proportional, dominant-pole and Type-III compensation. The analysis of SHO in discontinuous conduction mode (DCM) for both the buck and the boost converters are also included to demonstrate the universality of the proposed approach. Crucial Cadence simulation results and measurement results are presented to verify the analysis.
Autors: Lin Cheng;Wing-Hung Ki;Fan Yang;Philip K. T. Mok;Xiaocheng Jing;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Mar 2017, volume: 64, issue:3, pages: 717 - 730
Publisher: IEEE
 
» Predicting the Influence of Microvascular Structure On Tumor Response to Radiotherapy
Abstract:
Objective: The purpose of this study is to investigate how theoretical predictions of tumor response to radiotherapy (RT) depend on the morphology and spatial representation of the microvascular network. Methods: A hybrid multiscale model, which couples a cellular automaton model of tumor growth with a model for oxygen transport from blood vessels, is used to predict the viable fraction of cells following one week of simulated RT. Both artificial and biologically derived three-dimensional (3-D) vessel networks of well vascularized tumors are considered and predictions compared with 2-D descriptions. Results: For literature-derived values of the cellular oxygen consumption rate there is little difference in predicted viable fraction when 3-D network representations of biological or artificial vessel networks are employed. Different 2-D representations are shown to either over- or under-estimate viable fractions relative to the 3-D cases, with predictions based on point-wise descriptions shown to have greater sensitivity to vessel network morphology. Conclusion: The predicted RT response is relatively insensitive to the morphology of the microvessel network when 3-D representations are adopted, however, sensitivity is greater in certain 2-D representations. Significance: By using realistic 3-D vessel network geometries this study shows that real and artificial network descriptions and assumptions of spatially uniform oxygen distributions lead to similar RT response predictions in relatively small tissue volumes. This suggests that either a more detailed description of oxygen transport in the microvasculature is required or that the oxygen enhancement ratio used in the well known linear-quadratic RT response model is relatively insensitive to microvascular structure.
Autors: James A. Grogan;Bostjan Markelc;Anthony J. Connor;Ruth J. Muschel;Joe M. Pitt-Francis;Philip K. Maini;Helen M. Byrne;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Mar 2017, volume: 64, issue:3, pages: 504 - 511
Publisher: IEEE
 
» Prediction of Energy Losses in Soft Magnetic Materials Under Arbitrary Induction Waveforms and DC Bias
Abstract:
The statistical theory of losses (STL) provides a simple and general method for the interpretation and prediction of the energy losses in soft magnetic materials. One basic application consists, for example, in the prediction of the loss under arbitrary induction waveform, starting from data available from conventional measurements performed under sinusoidal flux. There are, however, persisting difficulties in assessing the loss when the induction waveform is affected by a dc bias, because this would require additional experimental data, seldom available to machine designers. In this paper, we overcome this problem applying, with suitable simplifications, the dynamic Preisach model. Here, the parameters of the STL model are obtained exploiting preemptive conventional measurements only. By this new simplified method, analytical expressions for the loss components are obtained under general supply conditions, including dc-biased induction waveforms.
Autors: Olivier de la Barrière;Carlo Ragusa;Carlo Appino;Fausto Fiorillo;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Mar 2017, volume: 64, issue:3, pages: 2522 - 2529
Publisher: IEEE
 
» Predictive and Core-Network Efficient RRC Signalling for Active State Handover in RANs With Control/Data Separation
Abstract:
Frequent handovers (HOs) in dense small cell deployment scenarios could lead to a dramatic increase in signaling overhead. This suggests a paradigm shift toward a signaling conscious cellular architecture with intelligent mobility management. In this direction, a futuristic radio access network with a logical separation between control and data planes has been proposed in research community. It aims to overcome limitations of the conventional architecture by providing high data rate services under the umbrella of a coverage layer in a dual connection mode. This approach enables signaling efficient HO procedures since the control plane remains unchanged when the users move within the footprint of the same umbrella. Considering this configuration, we propose a core-network efficient radio resource control signaling scheme for active state HO and develop an analytical framework to evaluate its signaling load as a function of network density, user mobility, and session characteristics. In addition, we propose an intelligent HO prediction scheme with advance resource preparation in order to minimize the HO signaling latency. Numerical and simulation results show promising gains in terms of reduction in HO latency and signaling load as compared with conventional approaches.
Autors: Abdelrahim Mohamed;Oluwakayode Onireti;Muhammad Ali Imran;Ali Imran;Rahim Tafazolli;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Mar 2017, volume: 16, issue:3, pages: 1423 - 1436
Publisher: IEEE
 
» Predictive Set Point Modulation to Mitigate Transients in Lightly Damped Balanced and Unbalanced Systems
Abstract:
Power system controllers are designed and tuned to achieve the desired dynamic performance under prespecified system conditions. However, changes in the system, e.g., load variation, generation changes, and faults, can cause departure of the system from previously assumed parameters. This in turn can change and reduce damping, which may enable large transients to violate the operational limits of a controlled apparatus. Set point automatic adjustment with correction enabled (SPAACE) is a strategy that modulates the set point of an apparatus to mitigate such transients. This paper 1) proposes a quadratic prediction algorithm for SPAACE to enhance its performance, 2) presents a supplemental strategy to improve set point tracking even when limits are not violated, 3) introduces an approach to implement SPAACE in unbalanced systems, and 4) analyzes the stability of SPAACE. Several case studies are presented to demonstrate the superior ability of this strategy for mitigating transients in different scenarios compared to conventional PI-based control strategies.
Autors: Hooman Ghaffarzadeh;Christopher Stone;Ali Mehrizi-Sani;
Appeared in: IEEE Transactions on Power Systems
Publication date: Mar 2017, volume: 32, issue:2, pages: 1041 - 1049
Publisher: IEEE
 
» Preserving Location Privacy of Connected Vehicles With Highly Accurate Location Updates
Abstract:
Connected vehicles are at risk of exposing their location history when using potentially untrusted location-based services (LBSs) in the driving process. We propose a method called mutually obfuscating paths (MOP) that enables vehicles to provide highly accurate realtime location updates to LBS while preventing the LBS from tracking vehicles. The instrument is to leverage connected vehicles’ two network interfaces: in-car LTE Internet (for accessing LBS) and car-to-car Dedicated short-range communications (DSRC)-communication (for obfuscating their paths). The main idea of MOP is that vehicles, when appropriate, generate made-up but plausible location updates for each other, making their paths continuously branching off from the LBS’ viewpoint. We evaluations show that MOP provides strong privacy protection even under continuous and highly accurate location updates.
Autors: Jaemin Lim;Hyunwoo Yu;Kiyeon Kim;Minho Kim;Suk-Bok Lee;
Appeared in: IEEE Communications Letters
Publication date: Mar 2017, volume: 21, issue:3, pages: 540 - 543
Publisher: IEEE
 
» Preventing Damage in Hydraulic Pumping Systems by using a Pressure Control Strategy
Abstract:
This paper presents an experimental study on the development, implementation, and tests of a control strategy applied to pressure control in hydraulic pumping systems. The strategy aims at avoiding severe damage on the hydraulic system due to Water Hammer effects. To accomplish this, it is proposed a suitable modulating control of the pump electric motor torque in order to keep the pressure values in a safe region, for all set of operating conditions. A rig system has been developed to perform experimental tests. From step response tests in the hydraulic rig system, a transfer function model relating the pipe pressure to the motor speed was identified and subsequently applied for PID controller design. The PID control synthesis was performed by using pole-placement techniques and its performance has been assessed in comparison to a PID controller adjusted by using Ziegler-Nichols rules. The obtained results show that the proposed control strategy was able to assure safe plant operation even in extreme operation conditions, as in case of Water Hammer effect.
Autors: Erick Melo Rocha;Walter Barra Junior;Abner Cesar Santos Bezerra;Hugo Menezes Barra;
Appeared in: IEEE Latin America Transactions
Publication date: Mar 2017, volume: 15, issue:3, pages: 445 - 453
Publisher: IEEE
 
» Pricing Electricity Through a Stochastic Non-Convex Market-Clearing Model
Abstract:
This paper proposes a pricing scheme for the day-ahead market in power systems with a large percentage of renewable stochastic production. To clear the day-ahead market, instead of a simplistic deterministic model, we use a two-stage stochastic programming model that embodies a prognosis of future operating conditions. Non-convexities due to start-up costs and the on/off status of generators and their minimum power outputs are properly taken into account. Our goal is to obtain uniform day-ahead clearing prices that deviate in the least possible manner from marginal prices and that allow producers to recover their costs without uplifts. The proposed methodology is illustrated using a simple example and a realistic case study.
Autors: Farzaneh Abbaspourtorbati;Antonio J. Conejo;Jianhui Wang;Rachid Cherkaoui;
Appeared in: IEEE Transactions on Power Systems
Publication date: Mar 2017, volume: 32, issue:2, pages: 1248 - 1259
Publisher: IEEE
 
» Pricing-Based Load Control of M2M Traffic for the LTE-A Random Access Channel
Abstract:
Existing cellular infrastructures have to be revisited for emerging machine-to-machine (M2M) traffic as semi-synchronized M2M arrivals may create a significant congestion resulting in a high access delay. In such a case, there is a strong need for service differentiation, since the delay requirements of IoT applications may vary greatly from delay-tolerant metering applications to security applications with stringent requirements. This problem has been receiving significant interest from the research community in the context of the LTE-A random access channel. Most studies, however, consider load control schemes with few fixed service classes, which can provide limited service differentiation. We propose an alternative scheme where the load is controlled by the price announced by the base station. The proposed method controls the load effectively and provides negligible delay for messages with the highest priority. It also enables low-cost wireless access to delay-tolerant messages by generating most of the revenue from high-priority messages. We derive pricing-based load control schemes for throughput and revenue maximization, and present the relationship between delay, revenue, and cost in both schemes. Our results suggest that dynamic pricing is a promising solution for major problems associated with cellular M2M traffic.
Autors: Mehmet Koseoglu;
Appeared in: IEEE Transactions on Communications
Publication date: Mar 2017, volume: 65, issue:3, pages: 1353 - 1365
Publisher: IEEE
 
» Printed Electronics: Effects of Bending and a Self-Compensation Means
Abstract:
A highly-worthy attribute of printed electronics is its possible realization on flexible-substrates that can be molded/bent. Heretofore, investigations into the effects of bending to printed circuit-elements/circuits remain not only largely incomplete, but an electronic/layout-means to mitigate said effects remains unreported/unresolved. We present a comprehensive investigation into the effects of concave/convex bending to printed circuit-elements and basic-circuits. The variations of said circuit-elements range from mild to severe, depicting that for accurate transfer-functions, capacitor-based circuits are preferred; and the variation directions of capacitors and resistors are the same, but the converse of transistors. For the inverter and ring-oscillator, the variations range from moderate-to-very-severe and severe-to-extremely-severe respectively for diode-connected and zero- connected topologies. This depicts that diode-connected circuits are preferred; and for speed, concave-bending is preferred. For the op-amp, the gain and gain-bandwidth variations range from mild-to-severe; and concave- and convex-bending is respectively preferred for gain-bandwidth and gain. By leveraging on the process-simplicity of our fully-additive all-air low-temperature printing processes, we propose a novel localized self-compensation means involving the partition of a given circuit-element/circuit into two-halves, each placed on the top/bottom of the flexible-substrate surface. The proposed means is highly efficacious– the reduction of variations ranges from to , yet without power, hardware or substrate-area overheads.
Autors: Jia Zhou;Tong Ge;Joseph S. Chang;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Mar 2017, volume: 64, issue:3, pages: 505 - 515
Publisher: IEEE
 
» PRISM: Person Reidentification via Structured Matching
Abstract:
Person reidentification (re-id), an emerging problem in visual surveillance, deals with maintaining the identities of individuals while they traverse various locations surveilled by a camera network. Motivated by real-world scenarios, we propose a method that seeks to simultaneously identify who among a group of individuals viewed in one view are present/absent in the other. From a visual perspective, re-id is challenging due to significant changes in visual appearance of individuals in cameras with different pose, illumination, and calibration. Globally, the challenge arises from the need to maintain structurally consistent matches among all the individual entities across different camera views. We propose person re-id via structured matching (PRISM), an SM method to jointly account for these challenges. We view the global problem as a weighted graph matching problem and estimate edge weights by learning to predict them based on the co-occurrences of visual patterns in the training examples. These co-occurrence-based scores in turn account for appearance changes by inferring likely and unlikely visual co-occurrences appearing in training instances. We implement PRISM on single-shot and multishot scenarios. PRISM uniformly outperforms state of the art in terms of matching rate while being robust and computationally efficient.
Autors: Ziming Zhang;Venkatesh Saligrama;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Mar 2017, volume: 27, issue:3, pages: 499 - 512
Publisher: IEEE
 
» Privacy-Preserving Learning Analytics: Challenges and Techniques
Abstract:
Educational data contains valuable information that can be harvested through learning analytics to provide new insights for a better education system. However, sharing or analysis of this data introduce privacy risks for the data subjects, mostly students. Existing work in the learning analytics literature identifies the need for privacy and pose interesting research directions, but fails to apply state of the art privacy protection methods with quantifiable and mathematically rigorous privacy guarantees. This work aims to employ and evaluate such methods on learning analytics by approaching the problem from two perspectives: (1) the data is anonymized and then shared with a learning analytics expert, and (2) the learning analytics expert is given a privacy-preserving interface that governs her access to the data. We develop proof-of-concept implementations of privacy preserving learning analytics tasks using both perspectives and run them on real and synthetic datasets. We also present an experimental study on the trade-off between individuals’ privacy and the accuracy of the learning analytics tasks.
Autors: Mehmet Emre Gursoy;Ali Inan;Mehmet Ercan Nergiz;Yucel Saygin;
Appeared in: IEEE Transactions on Learning Technologies
Publication date: Mar 2017, volume: 10, issue:1, pages: 68 - 81
Publisher: IEEE
 
» Privacy-Preserving Route Reporting Schemes for Traffic Management Systems
Abstract:
In this paper, we propose privacy-preserving route reporting schemes for traffic management for both infrastructure-supported and self-organizing vehicular ad hoc networks (VANETs). Using only pseudonyms and anonymous authentication to conceal the real identity of the drivers cannot fully preserve the drivers' privacy because the reported future positions can be used to link pseudonyms and identify the drivers, e.g., from the locations they visit. Motivated by the fact that traffic management systems do not need to know the vehicles' individual routes and the total number of vehicles in each road segment would suffice, the proposed schemes aggregate the vehicles' routes. Countering the collusion attacks is usually hard, particularly in a self-organizing setting. The concept we use to mitigate the attack is that one vehicle is not trusted to run the scheme because it can be curious to know the drivers' routes, but these schemes are run by multiple vehicles. Our ns-2 simulation results and analysis have demonstrated that our schemes can preserve the drivers' privacy with acceptable overhead.
Autors: Khaled Rabieh;Mohamed M. E. A. Mahmoud;Mohamed Younis;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Mar 2017, volume: 66, issue:3, pages: 2703 - 2713
Publisher: IEEE
 
» Probabilistic Assessment and Evaluation of Transients in a Medium-Voltage Three-Phase Capacitor Bank Energized by Unsynchronized Vacuum Switchgears
Abstract:
This paper presents a case study of a medium-voltage three-phase capacitor bank (CB) energization, based on an unsynchronized switching scheme using three independent pole vacuum switches simultaneously commanded. The motivations are cost reduction and simplification of the switching scheme. The maximum current and voltage peaks during transients caused by connection of CB with three independent pole switches or a three-phase mechanically coupled switch are compared. A probabilistic assessment for the overcurrents and overvoltages based on Monte Carlo simulation is also performed. The obtained results show that three single-phase unsynchronized switches could be used in a CB, with good transitory response.
Autors: Alysson Augusto Pereira Machado;Hélio Marcos André Antunes;Igor Amariz Pires;Sidelmo Magalhães Silva;Braz de Jesus Cardoso Filho;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Mar 2017, volume: 53, issue:2, pages: 918 - 928
Publisher: IEEE
 
» Probabilistic Caching in Wireless D2D Networks: Cache Hit Optimal Versus Throughput Optimal
Abstract:
Departing from the conventional cache hit optimization in cache-enabled wireless networks, we consider an alternative optimization approach for the probabilistic caching placement in stochastic wireless D2D caching networks taking into account the reliability of D2D transmissions. Using tools from stochastic geometry, we provide a closed-form approximation of cache-aided throughput, which measures the density of successfully served requests by local device caches, and we obtain the optimal caching probabilities via numerical optimization. Compared with the cache-hit-optimal case, the optimal caching probabilities obtained by cache-aided throughput optimization show notable gain in terms of the density of successfully served user requests, particularly in dense user environments.
Autors: Zheng Chen;Nikolaos Pappas;Marios Kountouris;
Appeared in: IEEE Communications Letters
Publication date: Mar 2017, volume: 21, issue:3, pages: 584 - 587
Publisher: IEEE
 
» Probabilistic Forecasting of Real-Time LMP and Network Congestion
Abstract:
The short-term forecasting of real-time locational marginal price (LMP) and network congestion is considered from a system operator perspective. A new probabilistic forecasting technique is proposed based on a multiparametric programming formulation that partitions the uncertainty parameter space into critical regions from which the conditional probability distribution of the real-time LMP/congestion is obtained. The proposed method incorporates load/generation forecast, time varying operation constraints, and contingency models. By shifting the computation associated with multiparametric programs offline, the online computational cost is significantly reduced. An online simulation technique by generating critical regions dynamically is also proposed, which results in several orders of magnitude improvement in the computational cost over standard Monte Carlo methods.
Autors: Yuting Ji;Robert J. Thomas;Lang Tong;
Appeared in: IEEE Transactions on Power Systems
Publication date: Mar 2017, volume: 32, issue:2, pages: 831 - 841
Publisher: IEEE
 
» Probabilistic Keys
Abstract:
Probabilistic databases address well the requirements of an increasing number of modern applications that produce large volumes of uncertain data from a variety of sources. Probabilistic keys enforce the integrity of entities in order to facilitate data processing in probabilistic database systems. For this purpose, we establish algorithms for an agile schema- and data-driven elicitation of the marginal probability by which keys should hold in a given application domain, and for reasoning about these keys. The efficiency of our elicitation framework is demonstrated theoretically and experimentally.
Autors: Pieta Brown;Sebastian Link;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Mar 2017, volume: 29, issue:3, pages: 670 - 682
Publisher: IEEE
 
» Probability-Driven Multibit Flip-Flop Integration With Clock Gating
Abstract:
Data-driven clock gated (DDCG) and multibit flip-flops (MBFFs) are two low-power design techniques that are usually treated separately. Combining these techniques into a single grouping algorithm and design flow enables further power savings. We study MBFF multiplicity and its synergy with FF data-to-clock toggling probabilities. A probabilistic model is implemented to maximize the expected energy savings by grouping FFs in increasing order of their data-to-clock toggling probabilities. We present a front-end design flow, guided by physical layout considerations for a 65-nm 32-bit MIPS and a 28-nm industrial network processor. It is shown to achieve the power savings of 23% and 17%, respectively, compared with designs with ordinary FFs. About half of the savings was due to integrating the DDCG into the MBFFs.
Autors: Doron Gluzer;Shmuel Wimer;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Mar 2017, volume: 25, issue:3, pages: 1173 - 1177
Publisher: IEEE
 
» PROMETHEUS: Procedural Methodology For Developing Heuristics Of Usability
Abstract:
Usability is a key discipline related to the development of modern software systems. Its goal is to assess the user-friendliness and effectiveness of a software product from the user point of view. Therefore, proper methodologies and techniques to perform this assessment are definitely relevant. Heuristic evaluation is probably the most commonly used method for usability assessment. Developed initially by Nielsen and Molich in the 90s, traditional heuristic evaluations rely on Nielsen's well-known 10 usability heuristics. However, recent evidence suggests that such heuristics are not sufficiently complete for dealing with new domains such as interactive television, virtual worlds, and many others. In addition to the lack of suitability of the traditional heuristics, it has been stated in the past years the lack of a robust methodology or process to effectively develop and validate these new domain-specific heuristics. In this paper we summarize current evidence regarding the lack of suitability of traditional heuristics, as well as the need for the development of new domain-specific heuristics. After identifying and acknowledging existing gaps in the state-of-the-art pointed by other researchers, we present PROMETHEUS, a PROcedural METhodology for developing HEuristics of USability. PROMETHEUS refines the methodology of Rusu et al. (2011), and is composed of 8 stages. PROMETHEUS clearly defines the artifacts that are required and produced by each stage, and also presents a set of quality indicators in order to assess the need for further refinement in the development of new heuristics. As an initial validation of PROMETHEUS, we apply a questionnaire to several researchers that have used the methodology of Rusu~etal, and we have also performed a small retrospective study, computing the quality indicators of several previous studies. Our results suggest that PROMETHEUS is a very promising methodology, and that the metrics and indicators are indeed pe- tinent with respect to the conclusions of previous works.
Autors: Cristhy Jimenez;Hector Allende Cid;Ismael Figueroa;
Appeared in: IEEE Latin America Transactions
Publication date: Mar 2017, volume: 15, issue:3, pages: 541 - 549
Publisher: IEEE
 
» Promoting Cooperation by the Social Incentive Mechanism in Mobile Crowdsensing
Abstract:
An incentive mechanism is important for mobile crowdsensing to recruit sufficient participants to complete large-scale sensing tasks with high quality. Previous incentive mechanisms have focused on quantifying participants' contribution to the quality of sensing and provide incentives directly to them. In this article, we introduce a novel approach, called the social incentive mechanism, which, surprisingly, incentivizes the social friends of the participants who perform the sensing tasks. The basic idea is to leverage the social ties among participants to promote global cooperation. Since the incentive that a participant receives largely relies on the behaviors of his/her social friends, participants have the motivation to impact their friends' behaviors through their social relationships in order to gain a higher payoff. This approach is applicable to many scenarios where the contributions to the quality of sensing among participants are interdependent, such as data aggregation. We have provided a case study which shows that the social incentive mechanism is more cost-effective than traditional incentive mechanisms.
Autors: Guang Yang;Shibo He;Zhiguo Shi;Jiming Chen;
Appeared in: IEEE Communications Magazine
Publication date: Mar 2017, volume: 55, issue:3, pages: 86 - 92
Publisher: IEEE
 
» Propelling Students Forward Through Submarine Racing
Abstract:
The International Submarine Races (ISR) are a biennial engineering design competition designed to encourage students to pursue education in marine engineering and ocean technology by participating in a premiere science, technology, engineering, and math (STEM) event with direct ship design engineering skills. The human-powered races are hosted every other June in the model basin at the Naval Surface Warfare Center, Carderock Division, in Bethesda, Maryland. The races are organized by the Foundation for Underwater Research and Education, a 501(c)3, not-forprofit foundation that provides funds and sponsors the ISR and engages attendees at STEM events. These human-powered submarine races offer aspiring young engineers a chance to put the principles they have learned in the classroom to practical application in the model basin. Real-world experience is an invaluable teacher. Submarine race teams learn through participation in the design competition and from each other. Studies show that students who put their skills to practical use fare far better in the post-college job market. Hundreds of ISR alumni have gone on to successful engineering careers in business, academia, and the public sector.
Autors: Kurt Yankaskas;
Appeared in: IEEE Potentials
Publication date: Mar 2017, volume: 36, issue:2, pages: 27 - 34
Publisher: IEEE
 
» Protocol Oblivious Forwarding (POF): Software-Defined Networking with Enhanced Programmability
Abstract:
Software-defined networking separates the control and forwarding planes of a network to make it more programmable and application- aware. As one of the initial implementations of SDN, OpenFlow abstracts a forwarding device as a flow table and realizes flow processing by applying the "match-and-act" principle. However, the protocol-dependent nature of OpenFlow still limits the programmability of the forwarding plane. Hence, in this article, we discuss how to leverage protocol-oblivious forwarding (POF) to further enhance the network programmability such that the forwarding plane becomes protocol-independent and can be dynamically reprogrammed to support new protocol stacks seamlessly. We first review the development of OpenFlow and explain the motivations for introducing POF. Then we explain the working principle of POF, discuss our efforts on realizing the POF development ecosystem, and show our implementation of POF-based source routing as a novel use case. Finally, we elaborate on the first WAN-based POF network testbed that includes POF switches located in two cities in China.
Autors: Shengru Li;Daoyun Hu;Wenjian Fang;Shoujiang Ma;Cen Chen;Huibai Huang;Zuqing Zhu;
Appeared in: IEEE Network
Publication date: Mar 2017, volume: 31, issue:2, pages: 58 - 66
Publisher: IEEE
 
» Proximate Standing Wave Feature of Magnetic Field and its Influence on the Performance of Wound Rotor Brushless Doubly-Fed Machine
Abstract:
This paper presents the proximate standing wave feature of the resultant magnetic field in a brushless doubly-fed machine (BDFM). To investigate the variation pattern of the resultant magnetic field and to predict its influence on machine performance, a wound rotor structure with low harmonic contents is designed. The variation law of resultant MMF is found to be similar to standing wave through summation of analytical equations for two magnetomotive forces (MMFs) with different pole pairs and opposite revolution directions. Based on this magnetic field of proximate standing wave, a new restriction for pole number combination is derived to eliminate asymmetrical magnetic forces. The torque angle of the BDFM is also accurately expressed by axis positions of MMFs. The finite element (FE) simulation verifies the proposed proximate standing wave feature of the air-gap magnetic field. New constraint on pole number combination is proved to be valid by comparing FE simulation results about magnetic force. Results from no load experiments and full load simulations are compared with data calculated by analytical methods. The good agreement validates the proposed torque angle expression and the torque angle curve.
Autors: Xi Chen;Xuefan Wang;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Mar 2017, volume: 32, issue:1, pages: 296 - 308
Publisher: IEEE
 
» Public Key Authentication and Key Agreement in IoT Devices With Minimal Airtime Consumption
Abstract:
Computational complexity of public key cryptography over sensor nodes is not anymore a blocking concern in modern devices which natively (and efficiently) support elliptic curve cryptography. The problem has rather shifted toward the significant airtime consumption required to exchange multiple messages and certificates so as to perform authentication and key agreement. This letter addresses such problem by exploiting implicit certificates (elliptic curve Qu-Vanstone). We specifically propose a novel key management protocol (KMP) which suitably integrates implicit certificates with a standard elliptic curve Diffie-Hellman exchange, and performs authentication and key derivation. As confirmed by a proof-of-concept implementation and relevant experimental results, the proposed KMP guarantees maximal airtime savings (up to 86.7%) with respect to conventional approaches, robust key negotiation, fast rekeying, and efficient protection against replay attacks.
Autors: Savio Sciancalepore;Giuseppe Piro;Gennaro Boggia;Giuseppe Bianchi;
Appeared in: IEEE Embedded Systems Letters
Publication date: Mar 2017, volume: 9, issue:1, pages: 1 - 4
Publisher: IEEE
 
» Publications & Initiatives: An Update on PES Activities [Leader's Corner]
Abstract:
Reports on recent PES society events, meetings, and activities.
Autors: Mariesa L. Crow;Damir Novosel;
Appeared in: IEEE Power and Energy Magazine
Publication date: Mar 2017, volume: 15, issue:2, pages: 8 - 12
Publisher: IEEE
 
» Pushing the Envelope for Heterogeneity: Multilayer and 3-D Heterogeneous Integrations for Next Generation Millimeter- and Submillimeter-Wave Circuits and Systems
Abstract:
Millimeter-wave (mmW) and submillimeter-wave (sub-mmW) or terahertz (THz; >300 GHz) frequencies are receiving increasing interest due to their distinct advantages, such as wider bandwidth, higher spatial (size) and temporal (time) resolution, the more compact antennas and other components they allow, and the reusability of frequencies [1], [2]. As a result, both military and commercial applications in areas of high-speed wireless communication [including fifth-generation (5G), i.e., 38 GHz and 68 GHz, 81-86 GHz, and 92?95 GHz], defense, security, and space science have been increasing rapidly [3], [4]. In recent years, mmW and THz applicaitons for spectroscopy and imaging, astronomy, and environmental/atmospheric study and monitoring have grown exponentially as advanced techniques [5]. At the same time, mmW/THz imaging is being viewed as a safe, low-cost alternative to conventional techniques for biological, security, and health-sciences applications [6], [7].
Autors: Kamal K. Samanta;
Appeared in: IEEE Microwave Magazine
Publication date: Mar 2017, volume: 18, issue:2, pages: 28 - 43
Publisher: IEEE
 
» Quad-Active-Bridge DC–DC Converter as Cross-Link for Medium-Voltage Modular Inverters
Abstract:
One of the main challenges of the solid-state transformer (SST) lies in the implementation of the dc–dc stage. In this paper, a quadruple-active-bridge (QAB) dc–dc converter is investigated to be used as a basic module of a modular three-stage SST. Besides the feature of high power density and soft-switching operation (also found in others converters), the QAB converter provides a solution with reduced number of high-frequency transformers, since more bridges are connected to the same multiwinding transformer. To ensure soft switching for the entire operation range of the QAB converter, the triangular current-mode modulation strategy, previously adopted for the dual-active-bridge converter, is extended to the QAB converter. The theoretical analysis is developed considering balanced (equal power processed by the medium-voltage (MV) cells) and unbalanced (unequal power processed by the MV cells) conditions. In order to validate the theoretical analysis developed in the paper, a 2-kW prototype is built and experimented.
Autors: Levy Ferreira Costa;Giampaolo Buticchi;Marco Liserre;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Mar 2017, volume: 53, issue:2, pages: 1243 - 1253
Publisher: IEEE
 
» Quadrature Spatial Modulation in MIMO Cognitive Radio Systems With Imperfect Channel Estimation and Limited Feedback
Abstract:
This paper studies the recent novel multiple-input multiple-output transmission technique called quadrature spatial modulation (QSM), in underlay cognitive radio (CR) systems. In particular, a multi-antenna secondary transmitter (ST) communicates with a multi-antenna secondary receiver (SR) in the presence of a primary receiver (PR). Considering only the statistical knowledge of the ST-PR channel gain, the QSM-CR scheme is investigated using a mean value (MV)-based power allocation strategy referred to as MV-based scheme. Furthermore, assuming that the ST-PR channel gain is perfectly known, the QSM-CR scheme is investigated using a power allocation method based on instantaneous channel state information (CSI), referred to as CSI-based scheme. In each scheme, considering imperfect ST-SR channel estimation, we study the secondary system performance, where closed-form expressions for the average pairwise error probability () are derived over Rayleigh fading channels. A tight upper bounded average bit error rate is obtained using the derived expression. Moreover, simple approximate expressions are obtained to get insights on the system diversity and channel estimation errors’ effects. Numerical results, which match with simulations, illustrate the robustness of QSM in enhancing the overall system performance in the presence of estimation errors.
Autors: Ali Afana;Islam Abu Mahady;Salama Ikki;
Appeared in: IEEE Transactions on Communications
Publication date: Mar 2017, volume: 65, issue:3, pages: 981 - 991
Publisher: IEEE
 
» Quality-oriented Rate Control and Resource Allocation in Time-Varying OFDMA Networks
Abstract:
In this paper, we propose a resource management scheme for on-demand video streaming in orthogonal frequency-division multiple access (OFDMA) networks with both time-varying channels and a user's personalized quality requirement. We design a user quality satisfaction model to evaluate the degree of the user quality satisfaction with respect to his/her personalized quality requirement. To perform the dynamic resource management, we propose a joint rate control (RC) associated with the quality adjustment at the application layer and resource allocation (RA) associated with the power allocation and subcarrier assignment at the physical layer. By using the Lyapunov optimization technique, we develop a joint RC and RA (JRCRA) algorithm to maximize the time-averaged quality satisfaction of all users (QSAU). We show that the QSAU achieved by the JRCRA algorithm without any prior knowledge of the channel statistics can arbitrarily attain the optimal QSAU achieved by the algorithm with a complete knowledge of the channel statistics. Simulation results verify the advantages of the proposed JRCRA algorithm.
Autors: Yashuang Guo;Qinghai Yang;Kyung Sup Kwak;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Mar 2017, volume: 66, issue:3, pages: 2324 - 2338
Publisher: IEEE
 
» Quantification of Shear Wave Scattering From Far-Surface Defects via Ultrasonic Wavefield Measurements
Abstract:
Nondestructive evaluation methods rely on prior knowledge of the expected interaction of ultrasonic waves with defects to inform detection and characterization decisions. Wavefield imaging, which refers to the measurement of signals originating from a spatially fixed source on a 2-D rectilinear grid, can be applied to visualize the effect of a subsurface scatterer on surface-measured wave motion. Here, obliquely incident shear waves are directed at the far surface of a plate containing a through-hole using the well-known angle-beam ultrasonic inspection method. A laser vibrometer and laboratory scanner are used to record the resulting out-of-plane motion on the plate surface in the vicinity of the through-hole both before and after a far-surface corner notch is introduced and subsequently enlarged. Waves scattered from the notch are isolated from the incident and hole-scattered waves via baseline subtraction of wavefields. The scattered wavefields are then filtered in the frequency–wavenumber domain to separate Rayleigh, shear, and longitudinal contributions to the scattered wavefield. The filtered wavefields are interpolated in space to obtain 2-D radial wavefield slices originating at the base of the notch. Each radial slice is analyzed to quantify scattering as a function of observation direction, resulting in Rayleigh, shear, and longitudinal scattering profiles for each notch size. The results are compared for four different notch sizes and two transducer orientations.
Autors: Alexander J. Dawson;Jennifer E. Michaels;Joseph W. Kummer;Thomas E. Michaels;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Mar 2017, volume: 64, issue:3, pages: 590 - 601
Publisher: IEEE
 
» Quantifying Interdependent Privacy Risks with Location Data
Abstract:
Co-location information about users is increasingly available online. For instance, mobile users more and more frequently report their co-locations with other users in the messages and in the pictures they post on social networking websites by tagging the names of the friends they are with. The users’ IP addresses also constitute a source of co-location information. Combined with (possibly obfuscated) location information, such co-locations can be used to improve the inference of the users’ locations, thus further threatening their location privacy: As co-location information is taken into account, not only a user's reported locations and mobility patterns can be used to localize her, but also those of her friends (and the friends of their friends and so on). In this paper, we study this problem by quantifying the effect of co-location information on location privacy, considering an adversary such as a social network operator that has access to such information. We formalize the problem and derive an optimal inference algorithm that incorporates such co-location information, yet at the cost of high complexity. We propose some approximate inference algorithms, including a solution that relies on the belief propagation algorithm executed on a general Bayesian network model, and we extensively evaluate their performance. Our experimental results show that, even in the case where the adversary considers co-locations of the targeted user with a single friend, the median location privacy of the user is decreased by up to 62 percent in a typical setting. We also study the effect of the different parameters (e.g., the settings of the location-privacy protection mechanisms) in different scenarios.
Autors: Alexandra-Mihaela Olteanu;Kévin Huguenin;Reza Shokri;Mathias Humbert;Jean-Pierre Hubaux;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Mar 2017, volume: 16, issue:3, pages: 829 - 842
Publisher: IEEE
 
» Quantitative Analysis of La and Al Additives Role on Dipole Magnitude Inducing Vt Shift in High-K/Metal Gate Stack
Abstract:
Voltage drop induced by an electrical dipole layer after the incorporation of La or Al in high-/metal gate-stack has been measured on nominal and beveled-SiOx devices and linearly correlated to the effective La/Al dose into the high-/SiOx stack determined through X-ray fluorescence spectroscopy. Electrical dipoles were experimentally estimated to be around −55 and +40 meV for each at/cm2 of effective La and Al dose, respectively.
Autors: C. Suarez-Segovia;C. Leroux;F. Domengie;G. Ghibaudo;
Appeared in: IEEE Electron Device Letters
Publication date: Mar 2017, volume: 38, issue:3, pages: 379 - 382
Publisher: IEEE
 
» Quantitative Recovery Conditions for Tree-Based Compressed Sensing
Abstract:
As shown by Blumensath and Davies (2009) and Baraniuk et al. (2010), signals whose wavelet coefficients exhibit a rooted tree structure can be recovered using specially adapted compressed sensing algorithms from just measurements, where is the sparsity of the signal. Motivated by these results, we introduce a simplified proportional-dimensional asymptotic framework, which enables the quantitative evaluation of recovery guarantees for tree-based compressed sensing. In the context of Gaussian matrices, we apply this framework to existing worst-case analysis of the iterative tree projection (ITP) algorithm, which makes use of the tree-based restricted isometry property (RIP). Within the same framework, we then obtain quantitative results based on a new method of analysis, which considers the fixed points of the algorithm. By exploiting the realistic average-case assumption that the measurements are statistically independent of the signal, we obtain significant quantitative improvements when compared with the tree-based RIP analysis. Our results have a refreshingly simple interpretation, explicitly determining a bound on the number of measurements that are required as a multiple of the sparsity. For example, we prove that exact recovery of binary tree-based signals from noiseless Gaussian measurements is asymptotically guaranteed for ITP with constant stepsize provided . All our results extend to the more realistic case in which measurements are corrupted by noise.
Autors: Coralia Cartis;Andrew Thompson;
Appeared in: IEEE Transactions on Information Theory
Publication date: Mar 2017, volume: 63, issue:3, pages: 1555 - 1571
Publisher: IEEE
 
» Quantum Efficiency Improvement of SOI p-i-n Lateral Diodes Operating as UV Detectors at High Temperatures
Abstract:
Thin-film lateral SOI p-i-n diodes can be used as photodetectors especially in the wavelength range of blue and ultra-violet (UV) radiation. Unlike vertical devices, lateral diodes can have depletion regions very close to the device surface, where the absorption of low-wavelengths radiation takes place. Due to this proximity to the surface, an MOS back-gate can control the charge density inside this region, allowing quantum efficiency improvement. This paper reports experimental results of SOI p-i-n photodetectors with different intrinsic lengths in the 300-500-K range, simultaneously considering back-gate bias and temperature influences. Indeed, the back-gate bias becomes very effective in terms of quantum efficiency control with up to 52.4% for at K in inversion mode, while in accumulation, the resulting efficiency was 48.2% at K for the device with at UV. These variations are related to the behavior of dark current and the recombination rate of the devices.
Autors: Carla Novo;Rudolf Bühler;João Baptista;Renato Giacomini;Aryan Afzalian;Denis Flandre;
Appeared in: IEEE Sensors Journal
Publication date: Mar 2017, volume: 17, issue:6, pages: 1641 - 1648
Publisher: IEEE
 
» Radar Coincidence Imaging with Stochastic Frequency Modulated Array
Abstract:
In radar sensing and imaging, the azimuth resolution is a main concern, which is limited by the antenna aperture, and as a result the targets within the beam cannot be distinguished. By enhancing the diversity of radiation, radar can obtain additional information for resolution. In this paper, a high-resolution staring imaging technique named radar coincidence imaging (RCI) is investigated. Originated from the classical optical coincidence imaging, the RCI captures super-resolution in azimuth, which breaks through the Rayleigh resolution limitation of antenna array by modulating the wavefront of transmissions. The spatial resolution of RCI is defined by the spatial correlation function of the stochastic radiation field. A scheme of RCI with a stochastic frequency modulated array using frequency-hopping waveforms is proposed, while the imaging model is established. Three image reconstruction algorithms, i.e. the pseudo-inverse algorithm, Tikhonov regularization method, and sparse reconstruction algorithm, are investigated and compared with respect to targets of different complexity. Performance analysis of these reconstruction methods in the presence of noise is presented by the relative imaging error. Finally, a typical RCI system based on the digital transmitter/receiver array is established. Outfield experiment results verify the effectiveness of the RCI.
Autors: Yongqiang Cheng;Xiaoli Zhou;Xianwu Xu;Yuliang Qin;Hongqiang Wang;
Appeared in: IEEE Journal of Selected Topics in Signal Processing
Publication date: Mar 2017, volume: 11, issue:2, pages: 414 - 427
Publisher: IEEE
 
» Radial-Flux Permanent-Magnet Limited-Angle Torque Motors
Abstract:
Slotless radial-flux permanent-magnet limited-angle torque motor with disturbed armature winding is analyzed in this paper. For the first time, the outer rotor structure is investigated for this type of the rotary actuator. The exact 2-D analytical modeling is applied to obtain the magnetic field parameters of the windings and excitation for both the outer rotor and the conventional inner rotor topologies. Also, the governing and geometrical equations are derived based on the analysis outcomes. Then, they are validated by applying the finite-elements tool. Both topologies are designed and compared with each other considering a variety of utilization parameters of these actuators. Avoiding saturation is considered as a designing criterion, which corresponds to the maximum torque production without distortion of linear characteristics in short-time operations. Experimental results show good accuracy of the theoretical design and numerical simulations. Comparison of the results shows significantly better performance of the new proposed actuator with the outer rotor structure against the conventional inner rotor type.
Autors: Parham Hekmati;Reza Yazdanpanah;Mojtaba Mirsalim;Ehsan Ghaemi;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Mar 2017, volume: 64, issue:3, pages: 1884 - 1892
Publisher: IEEE
 
» Radio Communications: Components, Systems and Networks
Abstract:
Autors: Amitabh Mishra;Tom Alexander;
Appeared in: IEEE Communications Magazine
Publication date: Mar 2017, volume: 55, issue:3, pages: 186 - 186
Publisher: IEEE
 
» Radio Resource Allocation for Multicarrier Low-Density-Spreading Multiple Access
Abstract:
Multicarrier low-density-spreading multiple access (MC-LDSMA) is a promising multiple access technique that enables near-optimal multiuser detection. In MC-LDSMA, each user's symbol is spread over a small set of subcarriers, and each subcarrier is shared by multiple users. The unique structure of MC-LDSMA makes the radio resource allocation more challenging compared with some well-known multiple access techniques. In this paper, we study the radio resource allocation for a single-cell MC-LDSMA system. First, we consider the single-user case and derive the optimal power allocation and subcarriers partitioning schemes. Then, by capitalizing on the optimal power allocation of the Gaussian multiple-access channel, we provide an optimal solution for MC-LDSMA that maximizes the users' weighted sum rate under relaxed constraints. Due to the prohibitive complexity of the optimal solution, suboptimal algorithms are proposed based on the guidelines inferred by the optimal solution. The performance of the proposed algorithms and the effect of subcarrier loading and spreading are evaluated through Monte Carlo simulations. Numerical results show that the proposed algorithms significantly outperform conventional static resource allocation, and MC-LDSMA can improve the system performance in terms of spectral efficiency and fairness in comparison with orthogonal frequency-division multiple access.
Autors: Mohammed Al-Imari;Muhammad Ali Imran;Pei Xiao;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Mar 2017, volume: 66, issue:3, pages: 2382 - 2393
Publisher: IEEE
 
» Radio Resource Sharing Framework for Cooperative Multioperator Networks With Dynamic Overflow Modeling
Abstract:
Due to exponentially growing wireless applications and services, traffic demand is rapidly increasing. To cope with such growth, wireless network operators seek radio resource cooperation strategies for their users with the highest grade of service possible. In this paper, we propose a set of analytical models for dynamic spectrum access (DSA) to attain intranetwork resource sharing agreements and adopt such strategies by sharing radio resources. The proposed models focus on reducing blocking probability for a secondary network to attain wireless services as a tradeoff with a marginal increase in the blocking probability of a primary network in return for monetary rewards. We derived the global balance equation and an explicit expression of the blocking probability for each resource sharing model. The robustness of the proposed analytical models is evaluated under different scenarios by considering varying traffic intensities and different network sizes and adding reserved resources. The results show that the blocking probabilities can be significantly reduced with the proposed DSA framework in comparison to the existing local spectrum access schemes.
Autors: Raouf Abozariba;Md Asaduzzaman;Mohammad Patwary;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Mar 2017, volume: 66, issue:3, pages: 2433 - 2447
Publisher: IEEE
 
» Random Access Scheme for Sporadic Users in 5G
Abstract:
Machine-type communication (MTC) devices usually have low-data rate, and in some applications, latency is critical. In long-term evolution, establishing a connection requires a relatively complex handshaking procedure. Such an approach is suitable for a system serving only a few high-activity users, but it becomes cumbersome for MTC traffic, where large amounts of low-activity users intermittently transmit a small number of packets. We propose a random access channel (RACH)-based scheme for the future 5G system that allows MTC users to send small packets within the random access burst. Device activity detection, channel estimation, authentication, and data decoding are performed simultaneously from the same access burst. In addition to the inherent reduction in energy consumption, the scheme eliminates the signaling overhead and creates more resources for data transmission. We have constructed an analytical framework for the detection performance of a multiple-input–multiple-output receiver in a frequency-selective channel. This has been validated with simulations, and results show that a one-shot correlate-and-cancel algorithm is sufficient for activity detection and channel estimation when the base station either employs multiple receive antennas or schedules multiple resource blocks for MTC RACH.
Autors: Yihenew Dagne Beyene;Riku Jäntti;Kalle Ruttik;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Mar 2017, volume: 16, issue:3, pages: 1823 - 1833
Publisher: IEEE
 
» Random Effects Models for Aggregate Lifetime Data
Abstract:
Field data provide important information about product quality and reliability. Many large organizations have developed ambitious reliability databases to trace field failure data of a variety of components on the systems they operate and maintain. Due to the exponential distribution assumption for the component lifetimes, the data in these databases are often aggregated. Specifically, individual lifetimes of the components are not available. Instead, each recorded data point is the cumulative operating time of one component position from system installation to the last component replacement, and the number of replacements in between. In the literature, the gamma distribution and the inverse Gaussian (IG) distribution have been used to fit the aggregate data, while the operating environment of different systems is often assumed the same. In order to capture possible heterogeneities among the systems, this study proposes the gamma random effects model and the IG random effects model. The expectation–maximization algorithm is used for point estimation of the parameters and an algorithm based on the generalized fiducial inference method is proposed for interval estimation. Simulation studies are conducted to assess the performance of the proposed inference methods. A real aggregate dataset is used for illustration.
Autors: Piao Chen;Zhi-Sheng Ye;
Appeared in: IEEE Transactions on Reliability
Publication date: Mar 2017, volume: 66, issue:1, pages: 76 - 83
Publisher: IEEE
 
» Random Hadamard Projections for Hyperspectral Unmixing
Abstract:
Dimensionality reduction based on random projections is investigated in the context of spectral unmixing of hyperspectral imagery with aims toward unmixing accuracy and computational efficiency. To this end, both Hadamard-based random projections—which significantly reduce computational costs with respect to more traditional Gaussian-driven projections—as well as a fast singular value decomposition deployed within a random-projection space are considered. Experimental results reveal that the methods based on Hadamard random projections offer abundance-estimation performance superior to other methods in conjunction with significantly reduced computational complexity.
Autors: Vineetha Menon;Qian Du;James E. Fowler;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Mar 2017, volume: 14, issue:3, pages: 419 - 423
Publisher: IEEE
 
» Rapid Skill Capture in a First-Person Shooter
Abstract:
Various aspects of computer game design, including adaptive elements of game levels, characteristics of “bot” behavior, and player matching in multiplayer games, would ideally be sensitive to a player’s skill level. Yet, while game difficulty and player learning have been explored in the context of games, there has been little work analyzing skill per se, and how this is related to the interaction of a player with the controls of the game—the player’s input. To this end, we present a data set of 476 game logs from over 40 players of a first-person shooter game (Red Eclipse) as a basis of a case study. We then extract features from the keyboard and mouse input and provide an analysis in relation to skill. Finally, we show that a player’s skill can be predicted using less than a minute of their keyboard presses. We suggest that the techniques used here are useful for adapting games to match players’ skill levels rapidly, arguably more rapidly than solutions based on performance averaging such as TrueSkill.
Autors: David Buckley;Ke Chen;Joshua Knowles;
Appeared in: IEEE Transactions on Computational Intelligence and AI in Games
Publication date: Mar 2017, volume: 9, issue:1, pages: 63 - 75
Publisher: IEEE
 
» Rapidly Prototyping Robots: Using Plates and Reinforced Flexures
Abstract:
In this article, we present plate and reinforced flexure (PARF) fabrication, an inexpensive, rapid fabrication technique for robot mechanisms inspired by the smart composite manufacturing (SCM) used in VelociRoACH [1] and RoboBee [2] designs. PARF extends SCM to larger sizes at low costs. We used PARF to develop a meter-scale hexapedal robot, BigANT [3], a design we made publicly available. Manufacture of BigANT requires minimal tooling-foam board, tape, a saw blade, and a knife; the chassis costs < US$20 in materials, encouraging its use in research, education, and recreation. We present a study of PARF joints, showing several variations spanning a range of fabrication effort and mechanical properties. PARF promises the possibility of quickly and inexpensively building robot mechanisms for tasks as the requirements arise, rather than relying on prefabricated robot bodies.
Autors: Ian Fitzner;Yue Sun;Vikram Sachdeva;Shai Revzen;
Appeared in: IEEE Robotics & Automation Magazine
Publication date: Mar 2017, volume: 24, issue:1, pages: 41 - 47
Publisher: IEEE
 
» Rate Region Boundary of the SISO Z-Interference Channel With Improper Signaling
Abstract:
This paper provides a complete characterization of the boundary of an achievable rate region, called the Pareto boundary, of the single-antenna Z interference channel (Z-IC), when interference is treated as noise and users transmit complex Gaussian signals that are allowed to be improper. By considering the augmented complex formulation, we derive a necessary and sufficient condition for improper signaling to be optimal. This condition is stated as a threshold on the interference channel coefficient, which is a function of the interfered user rate and which allows insightful interpretations into the behavior of the achievable rates in terms of the circularity coefficient (i.e., degree of impropriety). Furthermore, the optimal circularity coefficient is provided in closed form. The simplicity of the obtained characterization permits interesting insights into when and how improper signaling outperforms proper signaling in the single-antenna Z-IC. We also provide an in-depth discussion on the optimal strategies and the properties of the Pareto boundary.
Autors: Christian Lameiro;Ignacio Santamaría;Peter J. Schreier;
Appeared in: IEEE Transactions on Communications
Publication date: Mar 2017, volume: 65, issue:3, pages: 1022 - 1034
Publisher: IEEE
 

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