#### Electrical and Electronics Engineering publications abstract of: 09-2017 sorted by title, page: 8

» Energy-Efficient and Process-Variation-Resilient Write Circuit Schemes for Spin Hall Effect MRAM Device
 Abstract:In this paper, various energy-efficient write schemes are proposed for switching operation of spin hall effect (SHE)-based magnetic tunnel junctions (MTJs). A transmission gate (TG)-based write scheme is proposed, which provides a symmetric and energy-efficient switching behavior. We have modeled an SHE-MTJ using precise physics equations, and then leveraged the model in SPICE circuit simulator to verify the functionality of our designs. Simulation results show the TG-based write scheme advantages in terms of device count and switching energy. In particular, it can operate at 12% higher clock frequency while realizing at least 13% reduction in energy consumption compared to the most energy-efficient write circuits. We have analyzed the performance of the implemented write circuits in presence of process variation (PV) in the transistors’ threshold voltage and SHE-MTJ dimensions. Results show that the proposed TG-based design is the second most PV-resilient write circuit scheme for SHE-MTJs among the implemented designs. Finally, we have proposed the 1TG-1T-1R SHE-based magnetic random access memory (MRAM) bit cell based on the TG-based write circuit. Comparisons with several of the most energy-efficient and variation-resilient SHE-MRAM cells indicate that 1TG-1T-1R delivers reduced energy consumption with 43.9% and 10.7% energy-delay product improvement, while incurring low area overhead. Autors: Ramtin Zand;Arman Roohi;Ronald F. DeMara; Appeared in: IEEE Transactions on Very Large Scale Integration Systems Publication date: Sep 2017, volume: 25, issue:9, pages: 2394 - 2401 Publisher: IEEE
» Energy-Efficient Cross-Layer Design of Wireless Mesh Networks for Content Sharing in Online Social Networks
 Abstract:Bearing in mind the associated security and privacy concerns, users in an online social network (OSN) normally communicate with their direct friends. We propose an energy-efficient cross-layer design for wireless mesh network (WMN) aided content sharing in OSN as a case study of the interplay between OSNs and technological networks. A power control aided WMN is proposed for energy-efficient content sharing. Based on our power control scheme in the physical layer, an interference-constrained-channel-reuse scheme and a Dijkstra algorithm aided energy-efficient routing protocol are invoked for the medium access control layer and for the network layer, respectively. Inspired by the tool of social network analysis, both the singular and composite betweenness metrics are invoked for quantifying the duty-cycle of mesh routers. The former only considers the topology of the mesh backbone, while the latter considers the topologies of both the OSN and the WMN. Furthermore, the singular/composite betweenness is exploited for designing sophisticated caching strategies in order to improve the content sharing performance. We demonstrate that our caching strategies are capable of reducing the total energy dissipation by as much as . Specifically, the composite betweenness based caching strategy is capable of reducing the energy dissipation of the mesh clients by , compared to its singular betweenness based counterpart. Autors: Jie Hu;Lie-Liang Yang;Lajos Hanzo; Appeared in: IEEE Transactions on Vehicular Technology Publication date: Sep 2017, volume: 66, issue:9, pages: 8495 - 8509 Publisher: IEEE
» Energy-Efficient Hardware Architecture of Self-Organizing Map for ECG Clustering in 65-nm CMOS
 Abstract:An energy-efficient hardware architecture of a self-organizing map (SOM) for ECG clustering is proposed. It detects an R-peak, reconstructs the QRS complex around it, and clusters the complex by calculating the Euclidean distance between the complex and the weight vectors of each cell in the SOM network (i.e., cells). In the operation mode, the cluster ID related to the minimum Euclidean distance is provided, while the tagged weight vectors are updated in the learning mode. The proposed SoC is in CMOS 65-nm LP, and it consumes 5.853 mW at V. Autors: Jaeyoung Kim;Pinaki Mazumder; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1097 - 1101 Publisher: IEEE
» Energy-Efficient Object Detection Using Semantic Decomposition
 Abstract:In this brief, we present a new approach to optimize energy efficiency of object detection tasks using semantic decomposition to build a hierarchical classification framework. We observe that certain semantic information like color/texture is common across various images in real-world data sets for object detection applications. We exploit these common semantic features to distinguish the objects of interest from the remaining inputs (nonobjects of interest) in a data set at a lower computational effort. We propose a 2-stage hierarchical classification framework, with increasing levels of complexity, wherein the first stage is trained to recognize the broad representative semantic features relevant to the object of interest. The first stage rejects the input instances that do not have the representative features and passes only the relevant instance to the second stage. Our methodology thus allows us to reject certain information at lower complexity and utilize the full computational effort of a network only on a smaller fraction of inputs resulting in energy-efficient detection. Autors: Priyadarshini Panda;Swagath Venkataramani;Abhronil Sengupta;Anand Raghunathan;Kaushik Roy; Appeared in: IEEE Transactions on Very Large Scale Integration Systems Publication date: Sep 2017, volume: 25, issue:9, pages: 2673 - 2677 Publisher: IEEE
» Energy-Efficient Resource Reuse Scheme for D2D Communications Underlaying Cellular Networks
 Abstract:This letter investigates energy-efficient downlink resource reuse strategies for device-to-device (D2D) communications underlying cellular networks. We aim to maximize the total energy efficiency of all D2D links while guaranteeing the quality of service of cellular users (CUs) and the power requirements for both base station and D2D links. Based on the analysis of the characteristics of optimal joint power control and D2D-CU matching strategy, we propose an energy-efficient iterative algorithm for D2D communications. Simulation results show that the proposed energy-efficient downlink resource reuse strategy achieves higher energy efficiency of D2D communications than existing schemes. Autors: Jinming Hu;Wei Heng;Xiang Li;Jing Wu; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 2097 - 2100 Publisher: IEEE
» Energy-Sharing Model With Price-Based Demand Response for Microgrids of Peer-to-Peer Prosumers
 Abstract:According to the feed-in tariff for encouraging local consumption of photovoltaic (PV) energy, the energy sharing among neighboring PV prosumers in the microgrid could be more economical than the independent operation of prosumers. For microgrids of peer-to-peer PV prosumers, an energy-sharing model with price-based demand response is proposed. First, a dynamical internal pricing model is formulated for the operation of energy-sharing zone, which is defined based on the supply and demand ratio (SDR) of shared PV energy. Moreover, considering the energy consumption flexibility of prosumers, an equivalent cost model is designed in terms of economic cost and users’ willingness. As the internal prices are coupled with SDR in the microgrid, the algorithm and implementation method for solving the model is designed on a distributed iterative way. Finally, through a practical case study, the effectiveness of the method is verified in terms of saving PV prosumers’ costs and improving the sharing of the PV energy. Autors: Nian Liu;Xinghuo Yu;Cheng Wang;Chaojie Li;Li Ma;Jinyong Lei; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3569 - 3583 Publisher: IEEE
» Energy-Spectral Efficiency Tradeoffs in 5G Multi-Operator Networks With Heterogeneous Constraints
 Abstract:Along with spectral efficiency (SE), energy efficiency (EE) is a key performance metric for the design of 5G and beyond 5G (B5G) wireless networks. At the same time, infrastructure sharing among multiple operators has also emerged as a new trend in wireless communication networks. This paper presents an optimization framework for EE and SE maximization in a network, where radio resources are shared among multiple operators. We define a heterogeneous service level agreement (SLA) framework for a shared network, in which the constraints of different operators are handled by two different multi-objective optimization approaches namely the utility profile and scalarization methods. Pareto-optimal solutions are obtained by merging these approaches with the theory of generalized fractional programming. The approach applies to both noise-limited and interference-limited systems, with single-carrier or multi-carrier transmission. Extensive numerical results illustrate the effect of the operator specific SLA requirements on the global spectral and EE. Three network scenarios are considered in the numerical results, each one corresponding to a different SLA, with different operator-specific EE and SE constraints. Autors: Osman Aydin;Eduard Axel Jorswieck;Danish Aziz;Alessio Zappone; Appeared in: IEEE Transactions on Wireless Communications Publication date: Sep 2017, volume: 16, issue:9, pages: 5869 - 5881 Publisher: IEEE
» Engineering a PVD-Based Graphene Synthesis Method
 Abstract:Graphene is an important nanomaterial with extraordinary properties. An established physical vapor deposition (PVD) based Graphene synthesis method is engineered in order to demonstrate the versatility of the growth method with respect to the quality and number of layers of synthesized Graphene. A statistical method known as factorial Design-of-Experiments (DoE) is demonstrated in this paper to determine key factors for synthesis of Graphene on Copper (Cu) using amorphous carbon (a-C) as the solid carbon source. Both qualitative and quantitative analysis are performed to determine a suitable recipe. Carbon source thickness (which is a-C) annealing temperature and annealing duration are varied to study their effect on the growth. Annealing temperature and a-C thickness are found to be significant factors for growth feasibility in a PVD-based growth, whereas annealing time is found to play a crucial role in growing different number of layers of Graphene with different quality. The quality and number of layers of Graphene are verified by Raman characterization. Autors: Udit Narula;Cher Ming Tan; Appeared in: IEEE Transactions on Nanotechnology Publication date: Sep 2017, volume: 16, issue:5, pages: 784 - 789 Publisher: IEEE
» Enhanced Channel Access for Connection State of Bluetooth Low Energy Networks
 Abstract:According to Bluetooth Low Energy (BLE) specifications, a pair of connected devices (master and slave) should sleep whenever packet transmission is failed twice consecutively, although they still have packets to be sent. However, when BLE devices are densely deployed in a small geographical area, such sleeping can occur frequently, and as a result, the BLE performance can be degraded largely. Moreover, when considering that a message consists of multiple packets in many Internet of things (IoT) applications, the situation gets worse because the master and slave of BLE alternately have the transmission opportunity not in the unit of message but in the unit of packet. In this paper, we suggest two enhancements of data channel access for improving the BLE performance by making up the above-mentioned weaknesses: One is to continue packet transmission by avoiding bad-quality channel via channel hopping instead of sleeping; the other is a message-based alternation of transmission opportunity between master and slave. We formulate a Markov model for analyzing the performance of the proposed scheme and derive a closed-form solution. The numerical results demonstrate that, from the proposed two enhancements, the throughput and delay performances of BLE are remarkably improved with a slight increase of consumed energy. Autors: Wha Sook Jeon;Dong Geun Jeong; Appeared in: IEEE Transactions on Vehicular Technology Publication date: Sep 2017, volume: 66, issue:9, pages: 8469 - 8481 Publisher: IEEE
» Enhanced Control of Cortical Pyramidal Neurons With Micromagnetic Stimulation
 Abstract:Magnetic stimulation is less sensitive to the inflammatory reactions that plague conventional electrode-based cortical implants and therefore may be useful as a next-generation (implanted) cortical prosthetic. The fields arising from micro-coils are quite small however and thus, their ability to modulate cortical activity must first be established. Here, we show that layer V pyramidal neurons (PNs) can be strongly activated by micro-coil stimulation and further, the asymmetric fields arising from such coils do not simultaneously activate horizontally-oriented axon fibers, thus confining activation to a focal region around the coil. The spatially-narrow fields from micro-coils allowed the sensitivity of different regions within a single PN to be compared: while the proximal axon was most sensitive in naïve cells, repetitive stimulation over the apical dendrite led to a change in state of the neuron that reduced thresholds there to below those of the axon. Thus, our results raise the possibility that regardless of the mode of stimulation, penetration depths that target specific portions of the apical dendrite may actually be more effective than those that target Layer 6. Interestingly, the state change had similar properties to state changes described previously at the systems level, suggesting a possible neuronal mechanism underlying such responses. Autors: Seung Woo Lee;Shelley I. Fried; Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering Publication date: Sep 2017, volume: 25, issue:9, pages: 1375 - 1386 Publisher: IEEE
» Enhanced Generic Nonlinear and Linearized Models of Wind Power Plants
 Abstract:This paper develops enhanced hybrid generic (nonlinear) models of Type-3 and Type-4 wind power plants (WPPs) and extracts the corresponding linear (small-signal) dynamic models for power system transient stability analysis. The models are hybrid in nature since they consider both continuous states and discrete logic-controlled variables. The introduced enhancements include (i) a freezing function to reactivate reactive power emulator of Type-3 and Type-4 WPPs, (ii) active-current command recalculation step for Type-3 WPP and (iii) elimination of an activating logic of PI-controller limits in real current control path. The main feature of the enhanced models is that they can replicate the field-verified responses of the built-in PSS/E software models in any adopted software platform. It should be noted that the generic models described in the technical literature do not necessarily provide such replication. The paper also deduces small-signal dynamic models of Type-3 and Type-4 WPPs and addresses the multiple eigen structures of the linearized enhanced generic model of Type-3 WPP, which has not been comprehensively discussed in the technical literature. The enhanced nonlinear hybrid models and the corresponding linearized models are evaluated and verified based on time-domain simulation studies in PSS/E and MATLAB platforms, using NPCC system as the test bed. Autors: Ahmed Mostafa Khalil;Reza Iravani; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 3968 - 3980 Publisher: IEEE
» Enhanced-Boost Quasi-Z-Source Inverters With Two-Switched Impedance Networks
 Abstract:In this paper, two topologies are presented for the enhanced-boost quasi-Z-source inverters (qZSI), namely continuous input current configuration and discontinuous input current configuration of enhanced-boost qZSI with two-switched impedance networks. Similar to enhanced-boost impedance-source inverters (ZSIs), these proposed inverter topologies possess very high boost voltage inversion at low shoot-through duty ratio and high modulation index to provide an improved quality output voltage. Compared to enhanced-boost ZSIs with two-switched Z-source impedance networks, these proposed inverter topologies share common ground with source and bridge inverter, overcome the starting inrush problem, and draw continuous input current and the lower voltage across the capacitors. Moreover, the input ripple current is negligible. This paper presents the operating principles and analysis of continuous input current configuration enhanced-boost qZSI with two-switched impedance networks and compares with ZSI, switched inductor ZSI, DA/CA-qZSI, and enhanced-boost ZSIs. The theoretical analysis is done and is validated through simulation and experimental results. Autors: Vadthya Jagan;Janardhana Kotturu;Sharmili Das; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 6885 - 6897 Publisher: IEEE
» Enhancement-Mode AlGaN/GaN Fin-MOSHEMTs on Si Substrate With Atomic Layer Epitaxy MgCaO
 Abstract:We have demonstrated high-performance enhancement-mode or normally-off AlGaN/GaN fin-MOSHEMTs on a Si substrate with various fin width of 100–210 nm using atomic layer epitaxy (ALE) MgCaO as the gate dielectric. Through the fixed negative charges in MgCaO depleting the channel at the fin sidewalls, in contrast to the usual positive charges in atomic layer deposited amorphous Al2O3, the threshold voltage () is positively shifted and normally-off device is realized. A high maximum drain current () of 670 mA/mm, high on/off ratio of 1010 ~ 1012, and of 1 V have been achieved on the device. Combining with negligible – hysteresis of 30 mV and current collapse, the ALE MgCaO fin-MOSHEMT turns out to be a promising candidate for the future GaN power device applications. Autors: Hong Zhou;Xiabing Lou;Sang Bok Kim;Kelson D. Chabak;Roy G. Gordon;Peide D. Ye; Appeared in: IEEE Electron Device Letters Publication date: Sep 2017, volume: 38, issue:9, pages: 1294 - 1297 Publisher: IEEE
» Enhancing end-user bandwidth using content sharing over optical access networks
 Abstract:A steady increase in the consumption of bandwidth-hungry Internet services (e.g., on-demand content) has resulted in a simultaneous increase of the end-user bandwidth demand. Moreover, the growing bandwidth demand is foreseen to immensely pressurize content delivery networks (CDNs) in the near future. CDNs stream these services through the core network on a per-user basis. Hence, the bandwidth consumed by a CDN increases when content is requested by multiple users. In this paper, we propose optical access network (OAN) architectures and associated media access control protocols that enhance the end-user bandwidth by facilitating supervised sharing of content among end users with security. This is an attractive solution for OANs, which otherwise require technology upgrade and redeployment of fiber infrastructure for enhancing the end-user bandwidth. The proposed schemes provide bandwidth benefits in the access network which are simultaneously observed at the metro and core network levels. In comparison, competent technologies like caching and P2P solutions provide bandwidth benefits at the metro and core network levels only, and do not enhance the enduser bandwidth. Analytical models are derived for the schemes proposed in this paper, as well as the caching and CDN solutions, in order to compare bandwidth benefits. Validation of the analytical models is performed using simulations. Autors: Chayan Bhar;Arnab Mitra;Goutam Das;Debasish Datta; Appeared in: IEEE/OSA Journal of Optical Communications and Networking Publication date: Sep 2017, volume: 9, issue:9, pages: 756 - 772 Publisher: IEEE
» Enhancing Multiuser MIMO Through Opportunistic D2D Cooperation
 Abstract:We propose a cellular architecture that combines multiuser MIMO downlink with opportunistic use of unlicensed Industrial, Scientific, and Medical Radio (ISM) bands to establish device-to-device (D2D) cooperation. The architecture consists of a physical-layer cooperation scheme based on forming downlink virtual MIMO channels through D2D relaying, and a novel resource allocation strategy for such D2D-enabled networks. We prove the approximate optimality of the physical-layer scheme, and demonstrate that such cooperation boosts the effective of the weakest user in the system, especially in the many-user regime, due to multiuser diversity. To harness this physical-layer scheme, we formulate the cooperative user scheduling and the relay selection problem using the network utility maximization framework. For such a cooperative network, we propose a novel utility metric that jointly captures fairness in throughput and the cost of relaying in the system. We propose a joint user scheduling and relay selection algorithm, which we prove to be asymptotically optimal. We study the architecture through system-level simulations over a wide range of scenarios. The highlight of these simulations is an approximately improvement in data rate for cell-edge (bottom fifth-percentile) users (over the state-of-the-art) while still improving the overall throughput, and considering various system constraints. Autors: Can Karakus;Suhas Diggavi; Appeared in: IEEE Transactions on Wireless Communications Publication date: Sep 2017, volume: 16, issue:9, pages: 5616 - 5629 Publisher: IEEE
» Enhancing Secrecy With Multiantenna Transmission in Millimeter Wave Vehicular Communication Systems
 Abstract:Millimeter wave (mmWave) vehicular communication systems will provide an abundance of bandwidth for the exchange of raw sensor data and support driver-assisted and safety-related functionalities. Lack of secure communication links, however, may lead to abuses and attacks that jeopardize the efficiency of transportation systems and the physical safety of drivers. In this paper, we propose two physical layer (PHY) security techniques for vehicular mmWave communication systems. The first technique uses multiple antennas with a single radio-frequency (RF) chain to transmit information symbols to a target receiver and noise-like signals in nonreceiver directions. The second technique uses multiple antennas with a few RF chains to transmit information symbols to a target receiver and opportunistically inject artificial noise in controlled directions, thereby reducing interference in vehicular environments. Theoretical and numerical results show that the proposed techniques provide higher secrecy rate when compared to traditional PHY security techniques that require digital or more complex antenna architectures. Autors: Mohammed E. Eltayeb;Junil Choi;Tareq Y. Al-Naffouri;Robert W. Heath; Appeared in: IEEE Transactions on Vehicular Technology Publication date: Sep 2017, volume: 66, issue:9, pages: 8139 - 8151 Publisher: IEEE
» Enhancing Spatio-Temporal Fusion of MODIS and Landsat Data by Incorporating 250 m MODIS Data
 Abstract:Spatio-temporal fusion of MODIS and Landsat data aims to produce new data that have simultaneously the Landsat spatial resolution and MODIS temporal resolution. It is an ill-posed problem involving large uncertainty, especially for reproduction of abrupt changes and heterogeneous landscapes. In this paper, we proposed to incorporate the freely available 250 m MODIS images into spatio-temporal fusion to increase prediction accuracy. The 250 m MODIS bands 1 and 2 are fused with 500 m MODIS bands 3–7 using the advanced area-to-point regression kriging approach. Based on a standard spatio-temporal fusion approach, the interim 250 m fused MODIS data are then downscaled to 30 m with the aid of the available 30 m Landsat data on temporally close days. The 250 m data can provide more information for the abrupt changes and heterogeneous landscapes than the original 500 m MODIS data, thus increasing the accuracy of spatio-temporal fusion predictions. The effectiveness of the proposed scheme was demonstrated using two datasets. Autors: Qunming Wang;Yihang Zhang;Alex O. Onojeghuo;Xiaolin Zhu;Peter M. Atkinson; Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing Publication date: Sep 2017, volume: 10, issue:9, pages: 4116 - 4123 Publisher: IEEE
» Enhancing Test Compression With Dependency Analysis for Multiple Expansion Ratios
 Abstract:Scan test data compression is widely used in industry to reduce test data volume (TDV) and test application time (TAT). This paper shows how multiple scan chain expansion ratios can help to obtain high test data compression in system-on-chips. Scan chains are partitioned with a higher expansion ratio than normal in scan compression mode and then are gradually concatenated based on a cost function to detect any faults that could not be detected at the higher expansion ratios. It improves the overall test compression ratio since it potentially allows faults to be detected at the highest expansion ratio. This paper introduces a new cost function to choose scan chain concatenation candidates for concatenation for multiple expansion ratios. To avoid TDV and TAT increase by scan concatenation, the proposed method takes a logic structure and scan chain length into consideration. Experiment results show the proposed method reduces TAT and TDV by 53%–64% compared with a traditional scan compression method. Autors: Taehee Lee;Nur A. Touba;Joon-Sung Yang; Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems Publication date: Sep 2017, volume: 36, issue:9, pages: 1571 - 1579 Publisher: IEEE
» Enhancing the survivability and power savings of 5G transport networks based on DWDM rings
 Abstract:So much has been promised by the fifth generation (5G), the revolution of mobile communications that allows for flexible, speedy, and efficient delivery of unlimited data and information sharing between people located anywhere and at any time. The road toward making 5G a reality, however, requires concerted efforts in designing both the underlying infrastructure and the enabling technologies to simultaneously satisfy not only capacity but also reliability, low latency, synchronization, security, and energy consumption requirements. In that respect, the transport segment of a 5G network, i.e., the backhaul network of mobile base stations (BSs) or fronthaul of remote radio units (RRUs), must not be overlooked. Further, any future design of a resilient 5G transport network must also consider the potential exploitation of switching on and off network resources such as RRUs and BSs to improve energy efficiency. At present, there are few inroads on 5G transport networks that provide resilience during sleep mode operation. Therefore, the focus of this work is aimed specifically at providing solutions to enhance both the survivability and power savings of mobile transport networks that implement sleep mode operation. We develop our solutions around a dense wavelength-division multiplexed (DWDM) optical ring transport network that has been previously proven to be energy efficient as a 5G transport network. Further, we propose two survivable schemes that exploit the inherent resiliency of the ring network. In conjunction with cw monitoring signals and highly sensitive monitoring modules, these schemes facilitate for the first time continuous monitoring of the network at all times, even during idle periods of transmission when transceivers are sleeping. That is, our proposed schemes enable network energy savings through sleep mode operation without having to compromise on failure detection time. Compared to a conventional ring architecture, our survivable schemes provide enha- ced connection availability and power savings at less than 0.2% incremental network cost. Based on performance evaluations for brownfield, duct reuse, and greenfield deployments, we provide guidance on the most suitable scheme for each considered scenario, thus driving the future choices of mobile network operators. Autors: Elaine Wong;Elena Grigoreva;Lena Wosinska;Carmen Mas Machuca; Appeared in: IEEE/OSA Journal of Optical Communications and Networking Publication date: Sep 2017, volume: 9, issue:9, pages: D74 - D85 Publisher: IEEE
» Erratum to “A 200–1380 kHz Quadrifrequency Focused Ultrasound Transducer for Neurostimulation in Rodents and Primates: Transcranial In Vitro Calibration and Numerical Study of the Influence of Skull Cavity”
 Abstract:In the above paper [1], one maximum pressure listed in Table I, page 719, should be corrected. This error occurred when reporting the maximum pressure estimated in the rat brain at 1380 kHz (line 4, last column). The right value (7 MPa) does not change the discussion, and is in line with the 83% estimated pressure gain that was initially reported in rat brain (line 7, last column). Here we provide the correct table. Autors: Charlotte Constans;Thomas Deffieux;Pierre Pouget;Mickael Tanter;Jean-François Aubry; Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control Publication date: Sep 2017, volume: 64, issue:9, pages: 1417 - 1417 Publisher: IEEE
» Error Characterization, Mitigation, and Recovery in Flash-Memory-Based Solid-State Drives
 Abstract:NAND flash memory is ubiquitous in everyday life today because its capacity has continuously increased and cost has continuously decreased over decades. This positive growth is a result of two key trends: 1) effective process technology scaling; and 2) multi-level (e.g., MLC, TLC) cell data coding. Unfortunately, the reliability of raw data stored in flash memory has also continued to become more difficult to ensure, because these two trends lead to 1) fewer electrons in the flash memory cell floating gate to represent the data; and 2) larger cell-to-cell interference and disturbance effects. Without mitigation, worsening reliability can reduce the lifetime of NAND flash memory. As a result, flash memory controllers in solid-state drives (SSDs) have become much more sophisticated: they incorporate many effective techniques to ensure the correct interpretation of noisy data stored in flash memory cells. In this article, we review recent advances in SSD error characterization, mitigation, and data recovery techniques for reliability and lifetime improvement. We provide rigorous experimental data from state-of-the-art MLC and TLC NAND flash devices on various types of flash memory errors, to motivate the need for such techniques. Based on the understanding developed by the experimental characterization, we describe several mitigation and recovery techniques, including 1) cell-to-cell interference mitigation; 2) optimal multi-level cell sensing; 3) error correction using state-of-the-art algorithms and methods; and 4) data recovery when error correction fails. We quantify the reliability improvement provided by each of these techniques. Looking forward, we briefly discuss how flash memory and these techniques could evolve into the future. Autors: Yu Cai;Saugata Ghose;Erich F. Haratsch;Yixin Luo;Onur Mutlu; Appeared in: Proceedings of the IEEE Publication date: Sep 2017, volume: 105, issue:9, pages: 1666 - 1704 Publisher: IEEE
» Error-Voltage-Based Open-Switch Fault Diagnosis Strategy for Matrix Converters with Model Predictive Control Method
 Abstract:This paper proposes an error-voltage-based open-switch fault-diagnosis a strategy for a matrix converter (MC). A finite control set model predictive control method is used to operate the MC. The MC system performances under normal operation and under a single open-switch fault operation are analyzed. A fault-diagnosis strategy has also been implemented in two steps. First, the faulty phase is detected and identified based on a comparison of the reference and estimated output line-to-line voltages. Then, the faulty switch is located by considering the switching states of the faulty phase. The proposed fault-diagnosis method is able to locate the faulty switch accurately and quickly without additional voltage sensors. Simulation and experimental results are presented to demonstrate the feasibility and effectiveness of the proposed strategy. Autors: Hanbing Dan;Tao Peng;Mei Su;Hui Deng;Qi Zhu;Ziyi Zhao;Patrick Wheeler; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4603 - 4612 Publisher: IEEE
» eShiver: Lateral Force Feedback on Fingertips through Oscillatory Motion of an Electroadhesive Surface
 Abstract:We describe a new haptic force feedback device capable of creating lateral shear force on a bare fingertip—the eShiver. The eShiver creates a net lateral force from in-plane oscillatory motion of a surface synchronized with a “friction switch” based on Johnsen-Rahbek electroadhesion. Using an artificial finger, a maximum net lateral force of 300 mN is achieved at 55 Hz lateral oscillation frequency, and net force is shown to be a function of velocity and applied voltage, as well as the phase between them. A second set of experiments is carried out on a human finger, and a lateral force of up to 450 mN is achieved at a lateral oscillation frequency of 1,000 Hz. This force is reached at a peak lateral surface velocity of 400 mm/s and a peak applied voltage of 400 V. We develop a simple lumped parameter model of the eShiver, and a time domain simulation of the artificial finger is shown to agree with the experimental results. Three distinct zones of operation are found, which predict the limitations of force generation and which may be used for optimization. The human finger is found to be similar to the artificial finger in its dependence on actuation parameters, suggesting that the same lumped parameter model may be applied, albeit with different parameters. Curiously, the friction force due to Johnsen-Rahbek electroadhesion is found to increase substantially over time as the finger remains in contact with the surface. Considerations for optimizing the performance of the eShiver are discussed. Autors: Joseph Mullenbach;Michael Peshkin;J. Edward Colgate; Appeared in: IEEE Transactions on Haptics Publication date: Sep 2017, volume: 10, issue:3, pages: 358 - 370 Publisher: IEEE
» ESO-Based Inertia Emulation and Rotor Speed Recovery Control for DFIGs
 Abstract:In recent years, with the ever increasing penetration of wind generation, great concerns have been raised since the constantly decline of system's inertia may considerably deteriorate the frequency stability of power system. In this regard, an inertial response control technique is proposed to enable wind generators to provide the power system with controlled inertia in need via releasing energy to or absorbing energy from the system. In this paper, an extended state observer (ESO)-based inertia emulation controller (InEC) is proposed for doubly-fed induction generators (DFIGs), which is shown to be robust to measurement noise and changing working conditions. In addition, to mitigate potential adverse impacts of rotor speed recovery control (RSRC) of DFIGs on system frequency, an ESO-based RSRC is derived, allowing a schedulable dynamic of speed recovery. Experiments carried out on a power hardware-in-loop testbed manifest that the proposed controllers outperform the traditional proportional–differential type InEC and proportional–integral type RSRC in performance and robustness. Autors: Feng Liu;Zhangwei Liu;Shengwei Mei;Wei Wei;Yaxin Yao; Appeared in: IEEE Transactions on Energy Conversion Publication date: Sep 2017, volume: 32, issue:3, pages: 1209 - 1219 Publisher: IEEE
» Establishing Effective Global Virtual Student Teams
 Abstract:Research problem: In the educational arena, virtual teams made up of students who are located in more than one country are becoming increasingly commonplace. However, studies of the technological, social, and organizational factors that contribute to the success of these global virtual student teams (GVSTs) have yet to be systematically identified and discussed. In this paper, we seek to address this gap in our knowledge, drawing on several years of experience with GVSTs and addressing the following research question: How can university instructors establish effective GVST projects? Situating the case: The cases that we explore in this paper involve GVSTs with team members located variously in Hong Kong (all four cases), the USA (two cases), the UK (one case), and Singapore (one case). Students are a mix of undergraduate and graduate. How the case was studied: Our pedagogical purpose for running the GVST projects was to expose students to international communication and negotiation practices. The case designs involved situations where the student team members had to work collaboratively on a variety of tasks. We collected observational data and survey data, and required the team members to submit individual reflective reports about their learning experiences. About the case: We examine cultural differences among teams. We also note how issues of time and space vary across these teams, and consider how sufficient trust may be developed between team members to ensure productive work. Conclusion: From the four cases, we elicit 10 pertinent operational factors that should be of value to educators planning GVST projects. Autors: Robert M. Davison;Niki Panteli;Andrew M. Hardin;Mark A. Fuller; Appeared in: IEEE Transactions on Professional Communication Publication date: Sep 2017, volume: 60, issue:3, pages: 317 - 329 Publisher: IEEE
» Estimating the Cross-Correlation Properties of Large-Scale Parameters in Multilink Distributed Antenna Systems: Synchronous Measurements Versus Repeated Measurements
» Estimation of Finger Joint Angles Based on Electromechanical Sensing of Wrist Shape
 Abstract:An approach to finger motion capture that places fewer restrictions on the usage environment and actions of the user is an important research topic in biomechanics and human-computer interaction. We proposed a system that electrically detects finger motion from the associated deformation of the wrist and estimates the finger joint angles using multiple regression models. A wrist-mounted sensing device with 16 electrodes detects deformation of the wrist from changes in electrical contact resistance at the skin. In this study, we experimentally investigated the accuracy of finger joint angle estimation, the adequacy of two multiple regression models, and the resolution of the estimation of total finger joint angles. In experiments, both the finger joint angles and the system output voltage were recorded as subjects performed flexion/extension of the fingers. These data were used for calibration using the least-squares method. The system was found to be capable of estimating the total finger joint angle with a root-mean-square error of 29–34 degrees. A multiple regression model with a second-order polynomial basis function was shown to be suitable for the estimation of all total finger joint angles, but not those of the thumb. Autors: Junki Kawaguchi;Shunsuke Yoshimoto;Yoshihiro Kuroda;Osamu Oshiro; Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering Publication date: Sep 2017, volume: 25, issue:9, pages: 1409 - 1418 Publisher: IEEE
» Estimation of Remaining Useful Lifetime of Piezoelectric Transducers Based on Self-Sensing
 Abstract:Piezoelectric transducers are used in a wide range of applications. Reliability of these transducers is an important aspect in their application. Prognostics, which involve continuous monitoring of the health of technical systems and using this information to estimate the current health state and consequently predict the remaining useful lifetime ( ), can be used to increase the reliability, safety, and availability of the transducers. This is achieved by utilizing the health state and predictions to adaptively control the usage of the components or to schedule appropriate maintenance without interrupting operation. In this work, a prognostic approach utilizing self-sensing, where electric signals of a piezoelectric transducer are used as the condition monitoring data, is proposed. The approach involves training machine learning algorithms to model the degradation of the transducers through a health index and the use of the learned model to estimate the health index of similar transducers. The current health index is then used to estimate of test components. The feasibility of the approach is demonstrated using piezoelectric bimorphs and the results show that the method is accurate in predicting the health index and . Autors: James Kuria Kimotho;Tobias Hemsel;Walter Sextro; Appeared in: IEEE Transactions on Reliability Publication date: Sep 2017, volume: 66, issue:3, pages: 914 - 923 Publisher: IEEE
» Estimation of Sampling Period for Stochastic Nonlinear Sampled-Data Systems With Emulated Controllers
 Abstract:This note focuses on determining the value of the maximum allowable sampling period (MASP) that guarantees the stability of stochastic nonlinear sampled-data systems with emulated controllers. Two methods are proposed to compute MASP, one based on sufficient Lyapunov-like conditions on stabilization of stochastic nonlinear systems in mean square and the other from applying Barbalat's Lemma. Comparison studies are made and illustrated for the two methods by a numerical example. Autors: Yong-Feng Gao;Xi-Ming Sun;Changyun Wen;Wei Wang; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4713 - 4718 Publisher: IEEE
» Ethics in Robotics Research: CERNA Mission and Context
 Abstract:This article summarizes the recommendations concerning robotics as issued by the Commission for the Ethics of Research in Information Sciences and Technologies (CERNA), the French advisory commission for the ethics of information and communication technology (ICT) research. Robotics has numerous applications in which its role can be overwhelming and may lead to unexpected consequences. In this rapidly evolving technological environment, CERNA does not set novel ethical standards but seeks to make ethical deliberation inseparable from scientific activity. Additionally, it provides tools and guidance for researchers and research institutions. Autors: Alexei Grinbaum;Raja Chatila;Laurence Devillers;Jean-Gabriel Ganascia;Catherine Tessier;Max Dauchet; Appeared in: IEEE Robotics & Automation Magazine Publication date: Sep 2017, volume: 24, issue:3, pages: 139 - 145 Publisher: IEEE
» Evaluating the Performance of Digital Modular Protection for Grid-Connected Permanent-Magnet-Generator-Based Wind Energy Conversion Systems With Battery Storage Systems
 Abstract:This paper develops and tests a new method for managing the responses of multiple digital relays employed in interconnected permanent-magnet generator (PMG)-based wind energy conversion systems (WECSs) with battery storage. The developed method utilizes digital relays (modules), each of which provides protection for a specific location of the PMG-based WECS and battery storage. The outputs of the developed digital protection scheme are trip signals to operate circuit breakers in PMG-based WECS, battery storage, and point-of-common-coupling. The modular digital protection is implemented for experimental testing on a 5-kW PMG-based WECS that has a 2.3-kW battery storage. Test results show that the developed protection can offer fast, accurate, and reliable responses to faults occurring in different parts of the tested WECS and battery storage. In addition, test results show that the modular digital protection has minor sensitivity to the location of faults, charge/discharge cycles of the battery storage, and/or levels of power delivery to the host grid. Autors: S. A. Saleh;Ryan Meng;Ryan McSheffery; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4186 - 4200 Publisher: IEEE
» Evaluation and Adjustment of the AMSR2 Snow Depth Algorithm for the Northern Xinjiang Region, China
 Abstract:It is still a challenge to accurately map snow depth using passive microwave remote sensing. This study first validates the standard AMSR2 snow depth product in Northern Xinjiang, China, and then proposes an improved snow depth retrieving algorithm using the AMSR2 brightness temperature data in combination with in-situ measurements in the same region. The results show that: 1) in the past 15 years the mean snow depth based on the metrological stations ranges from 1.1 to 20.4 cm (mean 8.9 cm); 2) the standard AMSR2 snow depth product overestimates (underestimates) snow depth when snow depth thinner (thicker) than 30 cm, with an overall increased estimation error (root mean squared error) as snow depth increase; and 3) for the ascending mode (AMSR2_A) and descending mode (AMSR2_D), our improved algorithm shows smaller bias (2.5 and 3.9 cm) and smaller error (6.9 and 8.2 cm) as compared with the standard AMSR2 products (5.7 and 6.7 cm) and (11.2 and 12.1 cm), respectively. This suggests that the improved algorithm based on brightness temperature data of AMSR2_A has better accuracy and smaller error and can be used to retrieve snow depth of nonforest areas in cold period in the Northern Xinjiang. Autors: Renping Zhang;Tiangang Liang;Qisheng Feng;Xiaodong Huang;Wei Wang;Hongjie Xie;Jing Guo; Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing Publication date: Sep 2017, volume: 10, issue:9, pages: 3892 - 3903 Publisher: IEEE
» Evaluation of a “Field Cage” for Electric Field Control in GaN-Based HEMTs That Extends the Scalability of Breakdown Into the kV Regime
 Abstract:A distributed impedance “field cage” structure is proposed and evaluated for electric field control in GaN-based, lateral high electron mobility transistors operating as kilovolt-range power devices. In this structure, a resistive voltage divider is used to control the electric field throughout the active region. The structure complements earlier proposals utilizing floating field plates that did not employ resistively connected elements. Transient results, not previously reported for field plate schemes using either floating or resistively connected field plates, are presented for ramps of V/ns. For both dc and transient results, the voltage between the gate and drain is laterally distributed, ensuring that the electric field profile between the gate and drain remains below the critical breakdown field as the source-to-drain voltage is increased. Our scheme indicates promise for achieving the breakdown voltage scalability to a few kilovolts. Autors: Brian D. Tierney;Sukwon Choi;Sandeepan DasGupta;Jeramy R. Dickerson;Shahed Reza;Robert J. Kaplar;Albert G. Baca;Matthew J. Marinella; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3740 - 3747 Publisher: IEEE
» Evaluation of Marine Surface Wind Speed Observations From AMSR2 on GCOM-W Satellite
 Abstract:Observations of marine surface scalar wind speeds from the advanced microwave scanning radiometer 2 (AMSR2), onboard the global change observation mission-water satellite (GCOM-W), were evaluated by comparisons with offshore moored buoy measurements, output from the European Centre for Medium Range Weather Forecast Reanalysis Interim, and observations by the RapidScat (RSCAT) scatterometer onboard the International Space Station. In general, the AMSR2 wind speeds agreed well with the reference data. The root mean square difference between the AMSR2 and buoy measurements was 1.09 ms–1, which is slightly larger than the mission goal of 1 ms–1 . Underestimation at low wind speeds (<5 ms–1) was found in the comparisons. The AMSR2 wind speeds were found to contain a slight scan bias; namely, wind speeds in the right swath are higher than those in the left swath by 0.2–0.3 ms–1. Systematic dependence of the wind speed bias on the wind direction relative to the AMSR2 looking direction was found in a residual analysis. Results of the triple collocation analysis suggest that the random errors in the AMSR2 wind speed are less than 1 ms–1 and are smaller than those in the outputs from the numerical weather prediction (NWP) models, if random errors in the reference wind data (buoy, NWP, and RSCAT) are considered explicitly. Autors: Naoto Ebuchi; Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing Publication date: Sep 2017, volume: 10, issue:9, pages: 3955 - 3962 Publisher: IEEE
» Evaluation of Modal Power Distribution of Automotive Optical Gigabit Ethernet Connections
 Abstract:Automotive optical gigabit Ethernet is a technology that is expected to realize autonomous driving cars with notable benefits: electromagnetic interference free, lighter weight, and higher data communication. Plastic optical fibers have been used in automotive optical networks since 1998. To secure a higher data rate, two issues must be considered: the need for modal power distribution (MPD) control and the lack of link margin. Here, we performed a combined study of MPD and the frequency characteristics of a 15-m optical fiber cable with multiple connections. The results reveal that the links have transmission directivity and the number of connections influences the bandwidth with different MPDs, as shown in encircled angular flux (EAF) profiles. We also show that automotive optical connections typically contain an air gap that generates higher mode radiation. To minimize this radiation, we filled the gap with a cured gel. We found that the EAF profile shifts from 13.8° to 15.4° at 50% EAF with a 1.75-dB insertion loss improvement based on the shift at z/a = 3.1 (where z indicates the axial misalignment at the connection, and a is the core radius). The approach presented here is an effective solution for facilitating the rapid realization of automotive optical gigabit communication. Autors: Shigeru Kobayashi;Koji Horiguchi;Yasuhiro Hyakutake;Okihiro Sugihara; Appeared in: Journal of Lightwave Technology Publication date: Sep 2017, volume: 35, issue:17, pages: 3664 - 3670 Publisher: IEEE
» Event-Triggered State Estimation With an Energy Harvesting Sensor
 Abstract:In this paper, a problem of event-triggered state estimation for a linear Gaussian system with an energy harvesting sensor is investigated. A stochastic energy-dependent event-triggering transmission protocol is proposed to balance the communication rate and estimation performance according to the sensor's battery energy. The joint conditional probability distribution of the state and sensor's energy level on the combined set-valued and point-valued event-triggered measurements available to the remote estimator is derived. Based on this distribution, the recursive minimum mean squared error estimates of the state and sensor energy level are obtained. Also, the relationship between the average communication rate and energy harvesting rate is discussed. Finally, a numerical example is provided to evaluate the effectiveness of the proposed results. Autors: Jiarao Huang;Dawei Shi;Tongwen Chen; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4768 - 4775 Publisher: IEEE
» Evidence of Hot-Electron Effects During Hard Switching of AlGaN/GaN HEMTs
 Abstract:This paper reports on the impact of soft- and hard-switching conditions on the dynamic ON-resistance of AlGaN/GaN high-electron mobility transistors. For this study, we used a special double pulse setup, which controls the overlapping of the drain and gate waveforms (thus inducing soft and hard switching), while measuring the corresponding impact on the ON-resistance, drain current, and electroluminescence (EL). The results demonstrate that the analyzed devices do not suffer from dynamic increase when they are submitted to soft switching up to V. On the contrary, hard-switching conditions lead to a measurable increase in the dynamic ON-resistance (dynamic-. The increase in dynamic induced by hard switching is ascribed to hot-electrons effects: during each switching event, the electrons in the channel are accelerated by the high electric field and subsequently trapped in the AlGaN/GaN heterostructure or at the surface. This hypothesis is supported by the following results: 1) the increase in is correlated with the EL signal measured under hard-switching conditions and 2) the impact of hard switching on dynamic becomes weaker at high-temperature levels, as the average energy of hot electrons decreases due to the increase scattering with the lattice. Autors: I. Rossetto;M. Meneghini;A. Tajalli;S. Dalcanale;C. De Santi;P. Moens;A. Banerjee;E. Zanoni;G. Meneghesso; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3734 - 3739 Publisher: IEEE
» Evidence of Time-Dependent Vertical Breakdown in GaN-on-Si HEMTs
 Abstract:This paper demonstrates and investigates the time-dependent vertical breakdown of GaN-on-Si power transistors. The study is based on electrical characterization, dc stress tests and electroluminescence measurements. We demonstrate the following original results: 1) when submitted to two-terminal (drain-to-substrate) stress, the AlGaN/GaN transistors show a time-dependent degradation process, which leads to the catastrophic failure of the devices; 2) time-to-failure follows a Weibull distribution and is exponentially dependent on stress voltage; 3) the degradation mechanism is strongly field dependent and weakly thermally activated, with an activation energy of 0.25 eV; and 4) emission microscopy suggests that vertical current flows under the whole drain area, possibly through extended defects. The catastrophic failure occurs at random positions under the drain contact. The time-dependent failure is ascribed to a percolation process activated by the high-electric field that leads to the generation of localized shunt paths between drain and substrate. Autors: Matteo Borga;Matteo Meneghini;Isabella Rossetto;Steve Stoffels;Niels Posthuma;Marleen Van Hove;Denis Marcon;Stefaan Decoutere;Gaudenzio Meneghesso;Enrico Zanoni; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3616 - 3621 Publisher: IEEE
» Evolutionary Behavior Tree Approaches for Navigating Platform Games
 Abstract:Computer games are highly dynamic environments, where players are faced with a multitude of potentially unseen scenarios. In this paper, AI controllers are applied to the Mario AI benchmark platform, by using the grammatical evolution system to evolve behavior tree structures. These controllers are either evolved to both deal with navigation and reactiveness to elements of the game or used in conjunction with a dynamic A* approach. The results obtained highlight the applicability of behavior trees as representations for evolutionary computation and their flexibility for incorporation of diverse algorithms to deal with specific aspects of bot control in game environments. Autors: Miguel Nicolau;Diego Perez-Liebana;Michael O’Neill;Anthony Brabazon; Appeared in: IEEE Transactions on Computational Intelligence and AI in Games Publication date: Sep 2017, volume: 9, issue:3, pages: 227 - 238 Publisher: IEEE
» Evolving Spatial Clusters of Genomic Regions From High-Throughput Chromatin Conformation Capture Data
 Abstract:High-throughput chromosome-conformation-capture (Hi-C) methods have revealed a multitude of structural insights into interphase chromosomes. In this paper, we elucidate the spatial clusters of genomic regions from Hi-C contact maps by formulating the underlying problem as a global optimization problem. Given its nonconvex objective and nonnegativity constraints, we implement several evolutionary algorithms and compare their performance with non-negative matrix factorization, revealing novel insights into the problem. In order to obtain robust and accurate spatial clusters, we propose and describe a novel hybrid differential evolution algorithm called HiCDE, which adopts non-negative matrix factorization as local search according to each candidate individual provided by differential evolution algorithm. Based on the fitness value of each individual, the population is partitioned into three subpopulations with different sizes; each subpopulation is equipped with a specific mutation strategy for either exploitation or exploration. Finally, all control parameters in the pool have equal probability to be selected for generating trial vectors. The effectiveness and robustness of HiCDE are supported by real-world performance benchmarking on chromosome-wide Hi-C contact maps of yeast and human, time complexity analysis, convergence analysis, parameter analysis, and case studies. Autors: Xiangtao Li;Shijing Ma;Ka-Chun Wong; Appeared in: IEEE Transactions on NanoBioscience Publication date: Sep 2017, volume: 16, issue:6, pages: 400 - 407 Publisher: IEEE
» Exact Statistical Characterization of $2\times 2$ Gram Matrices with Arbitrary Variance Profile
 Abstract:This paper is concerned with the statistical properties of the Gram matrix , where is a complex central Gaussian matrix whose elements have arbitrary variances. With such arbitrary variance profile, this random matrix model fundamentally departs from classical Wishart models and presents a significant challenge as the classical analytical toolbox no longer directly applies. We derive new exact expressions for the distribution of and that of its eigenvalues by means of an explicit parameterization of the group of unitary matrices. Our results yield remarkably simple expressions, which are further leveraged to study the outage data rate of a dual-antenna communication system under different variance profiles. Autors: Nicolas Auguin;David Morales-Jimenez;Matthew R. McKay; Appeared in: IEEE Transactions on Vehicular Technology Publication date: Sep 2017, volume: 66, issue:9, pages: 8575 - 8579 Publisher: IEEE
» Experiences With an Optimal Estimation Algorithm for Surface and Atmospheric Parameter Retrieval From Passive Microwave Data in the Arctic
 Abstract:We present experiences in using an integrated retrieval method for atmospheric and surface parameters in the Arctic using passive microwave data from the AMSR-E radiometer. The core of the method is a forward model which can ingest bulk data for seven geophysical parameters to reproduce the brightness temperatures observed by a passive microwave radiometer. The retrieval method inverts the forward model and produces ensembles of the seven parameters, wind speed, integrated water vapor, liquid water path, sea and ice temperature, sea ice concentration and multiyear ice fraction. The method is constrained using numerical weather prediction data in order to retrieve a set of geophysical parameters that best fit the measurements. A sensitivity study demonstrates the method is robust and that the solution it provides is not dependent on initialization conditions. The retrieval parameters have been compared with the Arctic Systems Reanalysis model data as well as columnar water vapor retrieved from satellite microwave sounders and the Remote Sensing Systems AMSR-E ocean retrieval product in order to determine the feasibility of using the same setup over pure surface with 100% and 0% sea ice cover, respectively. Sea ice concentration retrieval shows good skill for pure surface cases. Ice types retrieval is in good agreement with scatterometer backscatter data. Deficiencies have been identified in using the forward model over sea ice for retrieving atmospheric parameters, that are connected to the treatment of surface emissivity and surface temperature. The retrieval agrees well with legacy atmospheric retrieval products in open ocean areas. Autors: Raul Cristian Scarlat;Georg Heygster;Leif Toudal Pedersen; Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing Publication date: Sep 2017, volume: 10, issue:9, pages: 3934 - 3947 Publisher: IEEE
» Experimental and Simulation Study of Silicon Nanowire Transistors Using Heavily Doped Channels
 Abstract:The experimental results from 8 nm diameter silicon nanowire junctionless field-effect transistors with gate lengths of 150 nm are presented that demonstrate on-currents up to 1.15 mA/m for 1.0 V and 2.52 mA/m for 1.8 V gate overdrive with an off-current set at 100 nA/m. On- to off-current ratios above with a subthreshold slope of 66 mV/dec are demonstrated at 25 C. Simulations using drift-diffusion which include density-gradient quantum corrections provide excellent agreement with the experimental results. The simulations demonstrate that the present silicon-dioxide gate dielectric only allows the gate to be scaled to 25 nm length before short-channel effects significantly reduce the performance. If high-K dielectrics replace some parts of the silicon dioxide then the technology can be scaled to at least 10 nm gatelength. Autors: Vihar P. Georgiev;Muhammad M. Mirza;Alexandru-Iustin Dochioiu;Fikru Adamu-Lema;Salvatore M. Amoroso;Ewan Towie;Craig Riddet;Donald A. MacLaren;Asen Asenov;Douglas J. Paul; Appeared in: IEEE Transactions on Nanotechnology Publication date: Sep 2017, volume: 16, issue:5, pages: 727 - 735 Publisher: IEEE
» Experimental Demonstration of Efficient Spin–Orbit Torque Switching of an MTJ With Sub-100 ns Pulses
 Abstract:Efficient generation of spin currents from charge currents is of high importance for memory and logic applications of spintronics. In particular, generation of spin currents from charge currents in high spin–orbit coupling metals has the potential to provide a scalable solution for embedded memory. We demonstrate a net reduction in the critical charge current for spin torque-driven magnetization reversal via using spin–orbit mediated spin current generation. We scaled the dimensions of the spin–orbit electrode to 400 nm and the nanomagnet to 270 nm nm in a three-terminal spin–orbit torque, magnetic tunnel junction (SOT-MTJ) geometry. Our estimated effective spin Hall angle is 0.15–0.20 using the ratio of zero-temperature critical current from spin Hall switching and estimated spin current density for switching the magnet. We show bidirectional transient switching using spin–orbit generated spin torque at 100 ns switching pulses reliably followed by transient read operations. We finally compare the static and dynamic response of the SOT-MTJ with transient spin circuit modeling showing the performance of scaled SOT-MTJs to enable nanosecond class non-volatile MTJs. Autors: Tanay A. Gosavi;Sasikanth Manipatruni;Sriharsha V. Aradhya;Graham E. Rowlands;Dmitri Nikonov;Ian A. Young;Sunil A. Bhave; Appeared in: IEEE Transactions on Magnetics Publication date: Sep 2017, volume: 53, issue:9, pages: 1 - 7 Publisher: IEEE
» Experimental Investigation of a New Tribo-Aeroelectrostatic Separation Process for Micronized Plastics From WEEE
 Abstract:Tribo-electrostatic separation of mm-size granular insulating materials is a process widely used in the plastics recycling industry. However, the separation of micronized plastics is still inefficient because of their tendency to aggregate. The paper is aimed at validating the feasibility of a new tribo-aero-electrostatic separation process for micronized mixed plastics originating from waste electric and electronic equipment. The separation process is based on a fluidized bed tribocharging system equipped with rotating roll electrode connected to a dc high-voltage supply. The micronized insulating materials to be separated (white and grey polyvinyl chloride particles of average size 20 µm) were tribocharged using the fluidization air provided by a variable-speed blower. The charged particles were pinned to the rotating electrode of opposite polarity. This process enabled the sorting of one product while the other materials were left in the fluidized bed. The new electrode configuration has the merit to significantly reduce the particle aggregation problem that affects the operation of other fluidized-bed-type tribocharging devices. The separation outcome, in terms of recovery and purity, depended on several factors, and was found to be optimal for a voltage of 35 kV and a rotation speed of roll electrode of 60 r/min. This new process was also tested for ternary mixtures of granular plastics and the obtained results demonstrate its effectiveness for recovering a targeted product, according to the voltage polarity, leaving the other products in the fluidized bed. Autors: Mohamed El-Mouloud Zelmat;Amar Tilmatine;Seddik Touhami;Abdelber Bendaoud;Karim Medles;Rabah Ouiddir;Lucian Dascalescu; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4950 - 4956 Publisher: IEEE
» Experimental Observation of Negative Susceptance in HfO2-Based RRAM Devices
 Abstract:Negative susceptance is experimentally measured in the low resistance state of TiN/Ti/HfO2/W resistive RAM memories. A meminductive-like behavior appears along with the memristive effects. A detailed study of small-signal parameters measured at 0 V after applying positive and negative voltage pulses is presented. A simple model for the conductive filaments consisting in a resistance in series with an inductance is used. In the equivalent circuit, both elements are in parallel with the geometrical capacitance of the structure. Both resistance and inductance show two clearly differentiate states. Positive voltages switch the device to the ON state, in which the resistance value is low and the inductance value is high. By applying appropriate negative voltages, the device switches to the OFF state, in which resistance value is high and inductance becomes negligible. The negative susceptance could be related to lags between current and electric field due to transport mechanisms occurring in the ON state. Autors: S. Dueñas;H. Castán;H. García;Óscar G. Ossorio;Luis A. Domínguez;E. Miranda; Appeared in: IEEE Electron Device Letters Publication date: Sep 2017, volume: 38, issue:9, pages: 1216 - 1219 Publisher: IEEE
» Experimental Validation of 3-D Magnet Eddy Current Loss Prediction in Surface-Mounted Permanent Magnet Machines
 Abstract:This paper presents the experimental validation of three-dimensional (3-D) Fourier method employed for predicting magnet eddy current loss in surface-mounted permanent magnet (SPM) machines. The magnet loss is measured for a 12-slot 14-pole SPM machine from experimental tests when the machine is operated with inverter under locked rotor conditions by repeating tests with two rotors, one with magnets and one without. The eddy current loss associated with each significant harmonic in the captured armature currents is predicted separately employing the developed method and the total magnet loss is evaluated by applying the principle of superposition. The magnet loss at real operating conditions of the machine is predicted from the method using the phase current captured when the SPM is operating at its maximum speed conditions. The result is used as an example to devise an effective means of further reduction in the total magnet loss. Autors: Sreeju Sreedharan Nair;Jiabin Wang;Tianfu Sun;Liang Chen;Robert Chin;Minos Beniakar;Dmitry Svechkarenko;Iakovos Manolas; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4380 - 4388 Publisher: IEEE
» Exploiting Unused Spare Columns and Replaced Columns to Enhance Memory ECC
 Abstract:Due to the emergence of extremely high density memory along with the growing number of embedded memories, memory yield is an important issue. Memory self-repair using redundancies to increase the yield of memories is widely used. Because high density memories are vulnerable to soft errors, memory error correction code (ECC) plays an important role in memory design. In this paper, methods to exploit spare columns including replaced defective columns are proposed to improve memory ECC. To utilize replaced defective columns, the defect information needs to be stored. Two approaches to store defect information are proposed—one is to use a spare column and the other is to use a content-addressable-memory. Experimental results show that the proposed method can significantly enhance the ECC performance. Autors: Hyunseung Han;Nur A. Touba;Joon-Sung Yang; Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems Publication date: Sep 2017, volume: 36, issue:9, pages: 1580 - 1591 Publisher: IEEE
» Exploiting WSSUS Multipath for GNSS Ranging
 Abstract:We propose a low-dimensional parameter estimation scheme for satellite-based ranging in the presence of an attenuated line-of-sight (LOS) signal and a time-varying number of multipath signals. This is of interest for landmobile users of global navigation satellite systems in diverse scattering environments with limited satellite visibility (e.g., a car moving through an urban canyon). Conventional ranging techniques, which rely solely on estimation of LOS parameters, ignore or suppress multipath and thus sacrifice available information; on the other hand, exhaustive approaches involving detection and estimation of each time-variant echo are too cumbersome in terms of parameter dimension. We suggest an unconditional maximum likelihood estimator (U-MLE) for joint estimation of LOS synchronization parameters and a small set of multipath distribution parameters. Our key assumptions are Gaussian wide-sense stationary uncorrelated scattering (WSSUS) and a known structure of the power delay profile. The proposed estimator uses as input data only a few complex-valued correlator outputs, which are provided by conventional navigation receivers, and its complexity is independent of the actual number of present echoes. Simulations demonstrate that the U-MLE improves accuracy and robustness of LOS synchronization for various model-matched and -mismatched multipath settings, including standardized and approved urban scenarios. Autors: Christoph Enneking;Felix Antreich; Appeared in: IEEE Transactions on Vehicular Technology Publication date: Sep 2017, volume: 66, issue:9, pages: 7663 - 7676 Publisher: IEEE
» Exploring Polymer Nanofiber Mechanics: A review of the methods for determining their properties.
 Abstract:Polymer nanofibers are increasingly being used in broad and diverse areas. In addition to the intrinsic chemical properties of the polymer, the physical and mechanical properties of the fiber are also important in determining its suitability for a given application. But measuring the mechanical properties and understanding their relationship to the structure and dimensions of the polymer nanofibers present some unique challenges. The atomic force microscope (AFM) has the force-sensing sensitivity and three-dimensional (3-D) spatial resolution necessary for this type of experiment. Several methods have been developed based on the AFM. The threepoint bending test approach is one of the most common, and several models have been developed for results interpretation. Autors: Ying Li;Wankei Wan; Appeared in: IEEE Nanotechnology Magazine Publication date: Sep 2017, volume: 11, issue:3, pages: 16 - 28 Publisher: IEEE
» Exploring RapidIO Technology Within a DAQ System Event Building Network
 Abstract:RapidIO (http://rapidio.org/) technology is a packet-switched high-performance fabric, which has been under active development since 1997. The technology is used in all 4G/LTE base stations worldwide. RapidIO is also used in embedded systems that require high reliability, low latency, and deterministic operations in a heterogeneous environment. RapidIO has several offloading features in hardware, therefore relieving the CPUs from time- and power-consuming work. Most importantly, it allows for remote direct memory access and thus zero-copy data transfer. In addition, it lends itself readily to integration with field-programmable gate arrays. In this paper, we investigate RapidIO as a technology for high-speed data acquisition (DAQ) networks, in particular the DAQ system of an LHC experiment. We present measurements using a generic multiprotocol event-building emulation tool that was developed for the LHCb experiment. Event building using a local area network, such as the one foreseen for the future LHCb DAQ, puts heavy requirements on the underlying network as all data sources from the collider will want to send to the same destinations at the same time. This may lead to an instantaneous overcommitment of the output buffers of the switches. We will present results from implementing an event building cluster based on RapidIO interconnect, focusing on the bandwidth capabilities of the technology as well as its scalability. Autors: Simaolhoda Baymani;Konstantinos Alexopoulos;Sébastien Valat; Appeared in: IEEE Transactions on Nuclear Science Publication date: Sep 2017, volume: 64, issue:9, pages: 2598 - 2605 Publisher: IEEE
» Exploring the Feasibility of a DNA Computer: Design of an ALU Using Sticker-Based DNA Model
 Abstract:Since its inception, DNA computing has advanced to offer an extremely powerful, energy-efficient emerging technology for solving hard computational problems with its inherent massive parallelism and extremely high data density. This would be much more powerful and general purpose when combined with other existing well-known algorithmic solutions that exist for conventional computing architectures using a suitable ALU. Thus, a specifically designed DNA Arithmetic and Logic Unit (ALU) that can address operations suitable for both domains can mitigate the gap between these two. An ALU must be able to perform all possible logic operations, including NOT, OR, AND, XOR, NOR, NAND, and XNOR; compare, shift etc., integer and floating point arithmetic operations (addition, subtraction, multiplication, and division). In this paper, design of an ALU has been proposed using sticker-based DNA model with experimental feasibility analysis. Novelties of this paper may be in manifold. First, the integer arithmetic operations performed here are 2s complement arithmetic, and the floating point operations follow the IEEE 754 floating point format, resembling closely to a conventional ALU. Also, the output of each operation can be reused for any next operation. So any algorithm or program logic that users can think of can be implemented directly on the DNA computer without any modification. Second, once the basic operations of sticker model can be automated, the implementations proposed in this paper become highly suitable to design a fully automated ALU. Third, proposed approaches are easy to implement. Finally, these approaches can work on sufficiently large binary numbers. Autors: Mayukh Sarkar;Prasun Ghosal;Saraju P. Mohanty; Appeared in: IEEE Transactions on NanoBioscience Publication date: Sep 2017, volume: 16, issue:6, pages: 383 - 399 Publisher: IEEE
» Extension of Map-Drift Algorithm for Highly Squinted SAR Autofocus
 Abstract:For highly squinted synthetic aperture radar (SAR) imaging, the Omega-k algorithm is generally accepted as an effective focusing processor. However, the performance of the Omega-k algorithm may be degraded by the trajectory deviations due to the precision limitation of the navigation system in airborne SAR. In this paper, we focus on the autofocusing approach, which is compatible with the Omega-k imaging for highly squinted SAR. This new autofocusing approach can be viewed as an extension version of the conventional map-drift (MD) algorithm, which has been widely used in the broadside mode. Two-step process is performed in the proposed autofocusing method: 1) the range-independent phase-error is first retrieved by a squinted MD (SMD) estimator; and 2) a squinted range-dependent MD (SRDMD) estimator is proposed to derive the residual range-variant phase-error. By correcting the phase-errors obtained from SMD and SRDMD, the highly squinted SAR data can be finally focused. The effectiveness of the proposed algorithm has been demonstrated by both simulated and real-measured SAR data in highly squinted mode. Autors: Lei Ran;Zheng Liu;Tao Li;Rong Xie;Lei Zhang; Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing Publication date: Sep 2017, volume: 10, issue:9, pages: 4032 - 4044 Publisher: IEEE
» Extensive Cooperative Caching in D2D Integrated Cellular Networks
 Abstract:Device-to-device (D2D) communication is a promising supplement to cellular networks, since it provides high rate transmission without changing network infrastructure. For a D2D integrated cellular network, caching popular content (e.g., multimedia files) at a base station (BS) or a D2D device near to a requesting user not only reduces content delivery delay, but also alleviates backhaul traffic load. In order to minimize content delivery delay, in this letter, we propose an extensive cooperative caching (EC-Caching) scheme, which allows inter-BS, inter-device and between-BS-and-device cooperation in content caching. Simulation results demonstrate that the extension in degree of cooperation between the caching nodes contributes significant performance gain in terms of content delivery delay and cache hit rate, especially in populated areas. Autors: Peng Lin;Qingyang Song;Yao Yu;Abbas Jamalipour; Appeared in: IEEE Communications Letters Publication date: Sep 2017, volume: 21, issue:9, pages: 2101 - 2104 Publisher: IEEE
» Extracting 3D Parametric Curves from 2D Images of Helical Objects
 Abstract:Helical objects occur in medicine, biology, cosmetics, nanotechnology, and engineering. Extracting a 3D parametric curve from a 2D image of a helical object has many practical applications, in particular being able to extract metrics such as tortuosity, frequency, and pitch. We present a method that is able to straighten the image object and derive a robust 3D helical curve from peaks in the object boundary. The algorithm has a small number of stable parameters that require little tuning, and the curve is validated against both synthetic and real-world data. The results show that the extracted 3D curve comes within close Hausdorff distance to the ground truth, and has near identical tortuosity for helical objects with a circular profile. Parameter insensitivity and robustness against high levels of image noise are demonstrated thoroughly and quantitatively. Autors: Chris G. Willcocks;Philip T. G. Jackson;Carl J. Nelson;Boguslaw Obara; Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence Publication date: Sep 2017, volume: 39, issue:9, pages: 1757 - 1769 Publisher: IEEE
» Extraction of Frequency-Dependent Characteristic Impedance and Complex Permittivity in Single-Ended and Edge-Coupled Transmission Lines Using the Calculated Series Parasitic Effects
 Abstract:This paper presents a method to obtain the characteristic impedance () and the complex permittivity () of single-ended and edge-coupled interconnects on printed circuit board (PCB) technology. For this purpose, experimentally determined propagation constant () data are used in combination with the frequency-dependent resistance () and inductance (). Due to the difficulty of directly obtaining and from measurements, closed-form equations are used to perform the corresponding calculation. In this regard, the current distribution effects are considered within the cross section of the signal traces and the ground plane. The proposal was validated for both, single-ended and edge-coupled PCB interconnects considering three cases: standard, medium-loss, and in low-loss materials. The results show that the extracted data are in agreement with values reported in material datasheets at 4 GHz. In this regard, the method is a good alternative to characterize planar transmission lines on PCB technology within the whole frequency range where the S-parameter measurements are performed. Autors: Diego M. Cortés-Hernández;Rosa J. Sánchez-Mesa;Svetlana C. Sejas-García;Reydezel Torres-Torres; Appeared in: IEEE Transactions on Microwave Theory and Techniques Publication date: Sep 2017, volume: 65, issue:9, pages: 3116 - 3122 Publisher: IEEE
» Extraction of Glacial Lake Outlines in Tibet Plateau Using Landsat 8 Imagery and Google Earth Engine
 Abstract:Glacial lake outburst floods (GLOFs) are among the most serious natural hazards in high mountain regions in the last several decades. The recent global warming has caused dramatic glacial lake changes and increased potential GLOF risk, particularly in Tibet Plateau (TP). Thus there is a pressing need to understand area and spatial distribution of glacial lakes at a large scale. Current efforts about glacial lake mapping in TP region is limited by spurious detections in the heterogeneous backgrounds. The nonlocal active contour algorithm, which takes full consideration of the regional heterogeneity in image, has been effectively applied in the field of medical image segmentation, but has not been tested at large scale of glaciated area yet. Moreover, the improved radiometric resolution and geographic coverage from Landsat 8 provides an opportunity to map glacial lakes. This study evaluated the potential of Landsat 8 images on annual glacial lake mapping in TP region which was characterized by various complex water conditions. The Google Earth Engine based cloud computing effectively facilitated the processing of a complete time series of Landsat 8 imagery from 2015 (156 path/rows and approximately 3580 scenes). Characteristics of glacial lake distribution were analyzed from aspects of size classes and elevation. Our results demonstrate that these strategies and methods automatically produce highly reliable glacial lake extents across the entire TP region, and are potentially applicable to other large-scale glacial lake mapping projects. Autors: Fang Chen;Meimei Zhang;Bangsen Tian;Zhen Li; Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing Publication date: Sep 2017, volume: 10, issue:9, pages: 4002 - 4009 Publisher: IEEE
» Fabrication of InGaAs-on-Insulator Substrates Using Direct Wafer-Bonding and Epitaxial Lift-Off Techniques
 Abstract:Defect less semiconductor-on-insulator (-OI) by a cost-effective and low-temperature process is strongly needed for monolithic 3-D integration. Toward this, in this paper, we present a cost-effective fabrication of the indium gallium arsenide-OI structure featuring the direct wafer bonding (DWB) and epitaxial lift-off (ELO) techniques as well as the reuse of the indium phosphide donor wafer. We systematically investigated the effects of the prepatterning of the III–V layer before DWB and surface reforming (hydrophilic) to speed up the ELO process for a fast and high-throughput process, which is essential for cost reduction. This method provides an excellent crystal quality of In0.53Ga0.47As on Si. Crystal quality of the film was evaluated using Raman spectra, and transmission electron microscope. Finally, we achieved good electrical properties of In0.53Ga0.47As-OI metal-oxide-semiconductor field-effect-transistors fabricated through the proposed DWB and ELO. Autors: Seong Kwang Kim;Jae-Phil Shim;Dae-Myeong Geum;Chang Zoo Kim;Han-Sung Kim;Jin Dong Song;Sung-Jin Choi;Dae Hwan Kim;Won Jun Choi;Hyung-Jun Kim;Dong Myong Kim;Sanghyeon Kim; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3601 - 3608 Publisher: IEEE
» Fabrication of Planar Back End of Line Compatible HfO$_x$ Complementary Resistive Switches
 Abstract:This paper presents the fabrication, together with morphological and electrical characterizations of complementary resistive switches using the nanodamascene process. The as-fabricated devices are fully embedded in an insulating oxide, opening the way for further process steps such as three-dimensional monolithic integration. Complementary resistive switches electrical performance is consistent with resistive random access memories fabricated and characterized with the same procedure that showed ratios of 100. Complementary operating voltages of and are obtained for 88 × 22 nm2 junction with a 6 nm thick HfO junction. Autors: Marina Labalette;Simon Jeannot;Serge Blonkowski;Yann Beilliard;Serge Ecoffey;Abdelkader Souifi;Dominique Drouin; Appeared in: IEEE Transactions on Nanotechnology Publication date: Sep 2017, volume: 16, issue:5, pages: 745 - 751 Publisher: IEEE
» Facet Segmentation-Based Line Segment Extraction for Large-Scale Point Clouds
 Abstract:As one of the most common features in the man-made environments, straight lines play an important role in many applications. In this paper, we present a new framework to extract line segments from large-scale point clouds. The proposed method is fast to produce results, easy for implementation and understanding, and suitable for various point cloud data. The key idea is to segment the input point cloud into a collection of facets efficiently. These facets provide sufficient information for determining linear features in the local planar region and make line segment extraction become relatively convenient. Moreover, we introduce the concept “number of false alarms” into 3-D point cloud context to filter the false positive line segment detections. We test our approach on various types of point clouds acquired from different ways. We also compared the proposed method with several other methods and provide both quantitative and visual comparison results. The experimental results show that our algorithm is efficient and effective, and produce more accurate and complete line segments than the comparative methods. To further verify the accuracy of the line segments extracted by the proposed method, we also present a line-based registration framework, which employs these line segments on point clouds registration. Autors: Yangbin Lin;Cheng Wang;Bili Chen;Dawei Zai;Jonathan Li; Appeared in: IEEE Transactions on Geoscience and Remote Sensing Publication date: Sep 2017, volume: 55, issue:9, pages: 4839 - 4854 Publisher: IEEE
» Facilitating the Integration of Renewables in Latin America: The Role of Hydropower Generation and Other Energy Storage Technologies
 Abstract:It is well known that storage facilities can provide value to various electricity sectors through several services, which we group into five main classes. Autors: Rodrigo Moreno;Rafael Ferreira;Luiz Barroso;Hugh Rudnick;Eduardo Pereira; Appeared in: IEEE Power and Energy Magazine Publication date: Sep 2017, volume: 15, issue:5, pages: 68 - 80 Publisher: IEEE
» Factor Graphs for Quantum Probabilities
 Abstract:A factor-graph representation of quantum-mechanical probabilities (involving any number of measurements) is proposed. Unlike standard statistical models, the proposed representation uses auxiliary variables (state variables) that are not random variables. All joint probability distributions are marginals of some complex-valued function , and it is demonstrated how the basic concepts of quantum mechanics relate to factorizations and marginals of . Autors: Hans-Andrea Loeliger;Pascal O. Vontobel; Appeared in: IEEE Transactions on Information Theory Publication date: Sep 2017, volume: 63, issue:9, pages: 5642 - 5665 Publisher: IEEE
» Falling Water, Rising Power
 Abstract:Hydropower is the production of electricity utilizing the force of falling water. Hydroelectric generators typically found in the United States range greatly in capacity from microhydro units rated between 5 kW-100 kW up to the large units at Grand Coulee Dam in Washington state, which are rated at 805 MW. The newly constructed Three Gorges Dam in China houses 32 units rated at 700 MW as well as two units rated at 50 MW to power the plant itself. Three Gorges is the world's largest hydroelectric power plant in terms of installed electrical generating capacity. Hydropower production can vary throughout the year as water supplies fluctuate. Peak hydropower generation typically occurs during the spring and summer months during snow melt and rain run-off season. Autors: Mark Skoric; Appeared in: IEEE Potentials Publication date: Sep 2017, volume: 36, issue:5, pages: 30 - 31 Publisher: IEEE
» Family of Soft-Switching Bidirectional Converters With Extended ZVS Range
 Abstract:This paper proposes a family of soft-switching bidirectional converters. In many applications, the bidirectional converters operate over a wide range of duty cycle and load variations. In the proposed converters, in order to extend the zero-voltage switching operation range, two supplemental voltage sources utilizing passive components are implemented in the auxiliary circuit. By using this method, the soft-switching features are ensured for an extensive range of the converter duty cycles. This is achieved independent of the output power value or the converter operation mode, and so, soft switching is ensured within the entire converter operating region. In these converters, all semiconductors components are soft switched, and the auxiliary circuit does not contribute to the complexity of the control circuit. Also, no extra voltage stress exists on the main switches and the voltage stress on the auxiliary switches is lower than the main switches voltage stress. In this paper, the proposed bidirectional buck/boost converter is analyzed and to confirm the feasibility of the proposed method, experimental results of a 150-W prototype converter are presented. Autors: Mohammad Reza Mohammadi;Hosein Farzanehfard; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7000 - 7008 Publisher: IEEE
» Farm Workers of the Future: Vision-Based Robotics for Broad-Acre Agriculture
 Abstract:Farmers are under growing pressure to intensify production to feed a growing population while managing environmental impact. Robotics has the potential to address these challenges by replacing large complex farm machinery with fleets of small autonomous robots. This article presents our research toward the goal of developing teams of autonomous robots that perform typical farm coverage operations. Making a large fleet of autonomous robots economical requires the use of inexpensive sensors, such as cameras for localization and obstacle avoidance. To this end, we describe a vision-based obstacle detection system that continually adapts to environmental and illumination variations and a visionassisted localization system that can guide a robot along crop rows with a complex appearance. Large fleets of robots will become time-consuming to monitor, control, and resupply. To reduce this burden, we describe a vision-based docking system for autonomously refilling liquid supplies and an interface for controlling multiple robots. Autors: David Ball;Patrick Ross;Andrew English;Peter Milani;Daniel Richards;Andrew Bate;Ben Upcroft;Gordon Wyeth;Peter Corke; Appeared in: IEEE Robotics & Automation Magazine Publication date: Sep 2017, volume: 24, issue:3, pages: 97 - 107 Publisher: IEEE
» Fascist Pigs [Book Review]
 Abstract: Autors: Nicholas G. Evans; Appeared in: IEEE Technology and Society Magazine Publication date: Sep 2017, volume: 36, issue:3, pages: 12 - 14 Publisher: IEEE
» Fascist Pigs: Technoscientific Oganisms andthe History of Fascism [Book Review]
 Abstract:In the current political climate, one may assume that the anti-intellectual, anti-expertise, anti-truth wave which is sweeping the globe, and that the rise of the far right necessarily spells an end for science-informed policy. The author of this book shows that this assumption is — for better or worse — misplaced. The author argues that agricultural science came to promote and embody fascist ideals in Portugal, Italy, and Germany in the early twentieth century. As a tool for engineering livestock and crops that would sustain and secure these aspiring empires, the author demonstrates how the organisms produced by scientists served to shape the narratives and politics of these regimes. The book begins with an introduction to the central premise of the book, which the author attributes to Canguilhem and Foucault: that biopolitics, the management and control of life, were central to fascism. The author then expands this account to encompass how new “techno-scientific organisms,” such as purpose-bred crops and animals, themselves interacted to promote and produce fascism. While biopolitics has understandably focused on human biopolitics in action under fascist rule, most infamously the Nazi’s experiment in human eugenics, the author develops an inquiry into the way that plants and animals informed and reinforced social change. The book is laid out in two primary sections. Section one, “Nation,” describes the national programs for Mussolini’s Italy and Salazar’s Portugal, and potatoes and the eponymous “fascist pigs” in the German Reich. The second section, “Empire,” focuses on the relationship between fascist techno-science and the imperial ambitions of each regime. Fascist Pigs offers more questions of science and politics than it answers, but in a style reminiscent of the opening book of a saga. This is an accessible and important book that I would recommend for students of science, technol- gy, and society as well as political science, and to philosophers of science and historians. Autors: Nicholas G. Evans; Appeared in: IEEE Technology and Society Magazine Publication date: Sep 2017, volume: 36, issue:3, pages: 12 - 14 Publisher: IEEE
» Fast Adaptive Finite-Time Voltage Regulation Control Algorithm for a Buck Converter System
 Abstract:A new voltage regulation control algorithm is designed for the buck-type dc-dc converter system in the presence of unknown input voltage and load variations. To enhance the voltage regulation time by using the finite-time control theory, a new fast voltage regulation control algorithm is designed that can guarantee that the output voltage converges to the reference voltage in a finite time. To address the unknown input voltage and load variations, two finite-time convergent observers are designed to estimate the unknown parameters in a finite time. Finally, an adaptive finite-time control algorithm is developed. Compared with the PI control algorithm, experimental results show that the proposed algorithm has a faster regulation performance and stronger performance on load-variation rejection. Autors: Yingying Cheng;Haibo Du;Chen Yang;Zuo Wang;Jinping Wang;Yigang He; Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs Publication date: Sep 2017, volume: 64, issue:9, pages: 1082 - 1086 Publisher: IEEE
» Fast Classification for Large Polarimetric SAR Data Based on Refined Spatial-Anchor Graph
 Abstract:The graph model-based semisupervised machine learning is well established. However, its computational complexity is still high in terms of the time consumption especially for large data. In this letter, we propose a fast semisupervised classification algorithm using the recently presented spatial-anchor graph for a large polarimetric synthetic aperture radar (Pol-SAR) data, named as Fast Spatial-Anchor Graph (FSAG) based algorithm. Based on an initial superpixel segmentation on the PolSAR image, the homogenous regions are obtained. The border pixels are reassigned to the most similar superpixel according to majority voting and distance measurement. Then, feature vectors are weighted within local homogenous regions. The refined spatial-anchor graph is constructed with these regions, and the semisupervised classification is conducted. Experimental results on synthesized and real PolSAR data indicate that the proposed FSAG greatly reduces time consumption and maintains the accuracy for terrain classifications compared with state-of-the-art graph-based approaches. Autors: Hongying Liu;Shuyuan Yang;Shuiping Gou;Puhua Chen;Yikai Wang;Licheng Jiao; Appeared in: IEEE Geoscience and Remote Sensing Letters Publication date: Sep 2017, volume: 14, issue:9, pages: 1589 - 1593 Publisher: IEEE
» Fast Determination of Saddle-Node Bifurcations via Parabolic Approximations in the Infeasible Region
 Abstract:This letter presents a simple methodology to quickly obtain the saddle-node bifurcation points of power systems by first solving a sequence of power flows that ends in the infeasible region and then performing a parabolic adjustment with the results of two infeasible cases. The proposed method exploits the ability of the factored load flow procedure to converge to complex solutions well beyond the maximum loading point. Test results on benchmark cases show that the new method yields a significant reduction in the computational cost, when compared to the previous approach based on exhaustive bisection search. Autors: Catalina Gómez-Quiles;Antonio Gómez-Expósito; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 4153 - 4154 Publisher: IEEE
» Fast Energy Efficient Radix-16 Sequential Multiplier
 Abstract:We propose a new sequential multiplier design that generates the radix-16 partial products (e.g., ) as two high () and low () components, such that , , where denotes the multiplicand. The required hard multiple is generated in a preliminary cycle to the advantage of reducing the cycle time of the main iteration. Two radix-16 carry-save adders are used to generate the radix-16 accumulated partial product. The synthesis results show improved latency, power dissipation, and energy consumption over the previous relevant designs at the cost of additional silicon area, while, however, the energy-area product is also lowered. Autors: Saba Amanollahi;Ghassem Jaberipur; Appeared in: IEEE Embedded Systems Letters Publication date: Sep 2017, volume: 9, issue:3, pages: 73 - 76 Publisher: IEEE
» Fast Low-Temperature Plasma Process for the Application of Flexible Tin-Oxide-Channel Thin Film Transistors
 Abstract:In this study, we demonstrated a p-type and n-type SnO TFTs on flexible polyimide substrate. The fabricated p-type SnO TFT showed a high of and a high of . Through optimizing the oxygen plasma condition, the n-type channel TFT transfered from prime p-type channel exhibits excellent characteristics, including a high on/off current ratio of , a low threshold voltage of −0.13 V, and a very high field-effect mobility of . This proposed low-temperature oxygen plasma treatment shows the potential in simplification of TFT process that can achieve n-type and p -type TFTs under the same device process. Autors: Po-Chun Chen;Yu-Chien Chiu;Zhi-Wei Zheng;Ming-Huei Lin;Chun-Hu Cheng;Guan-Lin Liou;Hsiao-Hsuan Hsu;Hsuan-ling Kao; Appeared in: IEEE Transactions on Nanotechnology Publication date: Sep 2017, volume: 16, issue:5, pages: 876 - 879 Publisher: IEEE
» Fast Moving Horizon State Estimation for Discrete-Time Systems Using Single and Multi Iteration Descent Methods
 Abstract:Descent algorithms based on the gradient, conjugate gradient, and Newton methods are investigated to perform optimization in moving horizon state estimation for discrete-time linear and nonlinear systems. Conditions that ensure the stability of the estimation error are established for single and multi iteration schemes with a least-squares cost function that takes into account only a batch of most recent information. Simulation results show the effectiveness of the proposed approaches also in comparison with techniques based on the Kalman filter. Autors: Angelo Alessandri;Mauro Gaggero; Appeared in: IEEE Transactions on Automatic Control Publication date: Sep 2017, volume: 62, issue:9, pages: 4499 - 4511 Publisher: IEEE
» Fast Operating Moving Coil Actuator for a Vacuum Interrupter
 Abstract:Vacuum circuit breakers are the dominant technology in medium-voltage distribution networks since they are environment friendly and maintenance free. It is a challenge to design an actuator for a vacuum circuit breaker, which achieves a high operating speed while maintaining high efficiency. A fast operating moving coil actuator for a vacuum interrupter has been developed. An analytical model of the actuator was initially developed and then simulated using a 3-D finite-element (FE) model. The model showed that the opening force was higher than the closing force due to asymmetry in the structure of the actuator, which resulted in a reluctance force component. The complete operating actuator prototype was built to avoid known problems such as contact popping, bounce, rebound, and welding. The magnetic field distribution and the static electromagnetic force on the moving coil were measured and provided a good correlation with the FE model simulation predications. The opening operation of the actuator prototype was compared for different capacitor supply voltages. A maximum velocity of 2.3 m/s was achieved when the capacitor was charged to 150 V. The actuator demonstrated successful operation at atmospheric pressure and also in a vacuum chamber. The opening time of the actuator in the vacuum was approximately 5 ms, compared to 5.5 ms at atmospheric pressure. We designed and built this actuator to illustrate that the moving coil actuator is capable of operating the vacuum circuit breaker quickly with high efficiency. Tests showed that further design optimizations for improving the operating speed and efficiency of the moving coil actuator are essential and the options have also been suggested. Autors: Xiaoze Pei;Alexander C. Smith;Roger Shuttleworth;Damian Sergio Vilchis-Rodriguez;Mike Barnes; Appeared in: IEEE Transactions on Energy Conversion Publication date: Sep 2017, volume: 32, issue:3, pages: 931 - 940 Publisher: IEEE
» Fast Stochastic Analysis of Electromigration in Power Distribution Networks
 Abstract:A fast and stochastic analysis methodology for electromigration (EM) assessment of power distribution networks is presented in this paper. We examine the impact of variability on EM time-to-failure (TTF), considering altered current densities due to global/local process variations as well as the fundamental factors that cause the conventional EM TTF distribution. Through the novel variations-aware current density model based on Hermite polynomial chaos, we demonstrate significant margins in EM lifetime when compared with the traditional worst case approach. On the other hand, we show that the traditional approach is altogether incompetent in handling transistor-level local variations leading to significantly optimistic lifetime estimates for lower metal level interconnects of power delivery network. Subsequently, we attempt to bridge the conventional, component-level EM verification method to the system level failures, inspired by the extreme order statistics. We make use of asymptotic order models to determine the TTF for the th component failure due to EM, and demonstrate application of this approach in developing IR drop aware system-level failure criteria. Autors: Palkesh Jain;Vivek Mishra;Sachin S. Sapatnekar; Appeared in: IEEE Transactions on Very Large Scale Integration Systems Publication date: Sep 2017, volume: 25, issue:9, pages: 2512 - 2524 Publisher: IEEE
» Fast Verification of Guide-Patterns for Directed Self-Assembly Lithography
 Abstract:Guide-patterns (GPs) are critical to the construction of contacts and vias in directed self-assembly (DSA) lithography. Simulations can be used to verify GPs, but runtime is excessive. Instead, we categorize the shapes of GPs using a small number of geometric parameters. Then a verification function is built to predict whether a GP will produce the required contacts, as follows: a vector in parameter space is constructed to represent each GP in a test set; the acceptability of each GP is then assessed by DSA simulation, and each vector is tagged “good” or “bad” accordingly; next, the parameter space is deformed to convert a radial distribution into one in which the good and bad vectors can be separated by a hyper-plane, which finally becomes the verification function. We also show how to reduce the dimensionality of the parameter space by principal component analysis, and how to generalize the geometric description of GPs to allow different types of GP to be verified in a uniform fashion. The proposed GP verification is demonstrated in 10 nm technology. Autors: Seongbo Shim;Youngsoo Shin; Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems Publication date: Sep 2017, volume: 36, issue:9, pages: 1522 - 1531 Publisher: IEEE
» Fast-Frequency Response Provided by DFIG-Wind Turbines and its Impact on the Grid
 Abstract:This paper presents a methodology for the analysis of frequency dynamics in large-scale power systems with high level of wind energy penetration by means of a simplified model for DFIG-based wind turbines. In addition, a virtual inertia controller version of the optimized power point tracking (OPPT) method is implemented for this kind of wind turbines, where the maximum power point tracking curve is shifted to drive variations in the active power injection as a function of both the grid frequency deviation and its time derivative. The proposed methodology integrates the model in a primary frequency control scheme to analyze the interaction with the rest of the plants in the power system. It is also proven that, under real wind conditions, the proposed version of the OPPT method allows us to smooth the wind power injected into the grid, thereby reducing frequency fluctuations. Autors: Danny Ochoa;Sergio Martinez; Appeared in: IEEE Transactions on Power Systems Publication date: Sep 2017, volume: 32, issue:5, pages: 4002 - 4011 Publisher: IEEE
» Fault-Tolerant Multilevel Topology Based on Three-Phase H-Bridge Inverters for Open-End Winding Induction Motor Drives
 Abstract:In this paper, a multilevel inverter based on three-phase H-bridge inverters for an open-end winding induction motor drive is presented and its fault-tolerance capability is investigated. The multilevel topology is obtained using three wye-connected three-phase H-bridge inverters to supply open-end winding induction motors. This topology has the ability to extend the maximum voltage applied to the motor windings up to two times the dc supply voltage of the three-phase inverters. For a given induction motor voltage, the topology allows the use of dc sources with a lower voltage rating. Consequently, faster power semiconductors can be used. This multilevel topology can be directly controlled by modifying known modulation concepts, such as sinusoidal pulse width modulation (PWM). In this study, two sinusoidal PWM modulation techniques will be implemented: the level-shifted carriers (phase disposition) and the phase-shifted modulator. Fault-tolerant operation under an open-switch fault without adding any extra components and without changing the modulation strategy is also proposed, adding fault-tolerant capability to the new topology. Experimental results of this multilevel inverter in normal operation and in fault tolerant mode are presented. The obtained results confirm the fault effectiveness of the proposed multilevel topology. Autors: Vitor Fernão Pires;Daniel Foito;J. Fernando Silva; Appeared in: IEEE Transactions on Energy Conversion Publication date: Sep 2017, volume: 32, issue:3, pages: 895 - 902 Publisher: IEEE
» Fear Not Distribution that Works [Open Letter]
 Abstract: Autors: Jefferey Dungen; Appeared in: IEEE Technology and Society Magazine Publication date: Sep 2017, volume: 36, issue:3, pages: 11 - 11 Publisher: IEEE
» Feasibility and Validation of 4-D Pulse Wave Imaging in Phantoms and In Vivo
 Abstract:Pulse wave imaging (PWI) is a noninvasive technique for tracking the propagation of the pulse wave along the arterial wall. The 3-D ultrasound imaging would aid in objectively estimating the pulse wave velocity (PWV) vector. This paper aims to introduce a novel PWV estimation method along the propagation direction, validate it in phantoms, and test its feasibility in vivo. A silicone vessel phantom consisting of a stiff and a soft segment along the longitudinal axis and a silicone vessel with a plaque were constructed. A 2-D array with a center frequency of 2.5 MHz was used. Propagation was successfully visualized in 3-D in each phantom and in vivo in six healthy subjects. In three of the healthy subjects, results were compared against conventional PWI using a linear array. PWVs were estimated in the stiff (3.42 ± 0.23 m ) and soft (2.41 ± 0.07 m ) phantom segments. Good agreement was found with the corresponding static testing values (stiff: 3.41 m and soft: 2.48 m ). PWI-derived vessel compliance values were validated with dynamic testing. Comprehensive views of pulse propagation in the plaque phantom were generated and compared against conventional PWI acquisitions. Good agreement was found in vivo between the results of 4-D PWI (4.80 ± 1.32 m ) and conventional PWI (4.28±1.20 m ). PWVs derived for all of the healthy subjects () were within the physiological range. Thus, the 4-D PWI was successfully validated in phantoms and used to image the pulse wave propagation in normal human subjects in vivo. Autors: Iason-Zacharias Apostolakis;Pierre Nauleau;Clement Papadacci;Matthew D. McGarry;Elisa E. Konofagou; Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control Publication date: Sep 2017, volume: 64, issue:9, pages: 1305 - 1317 Publisher: IEEE
» Feast or Famine [From the Editor's Desk]
 Abstract:Presents the introductory editorial for this issue of the publication. Autors: Alfy Riddle; Appeared in: IEEE Microwave Magazine Publication date: Sep 2017, volume: 18, issue:6, pages: 6 - 22 Publisher: IEEE
» Features of Capacitive Displacement Sensing That Provide High-Accuracy Measurements with Reduced Manufacturing Precision
 Abstract:The capacitive displacement sensing method based on time grating employs a set of movable induction electrodes suspended with some gap width above a set of fixed excitation electrodes, and signals are obtained through electric field coupling. In this paper, we consider three features of time-grating capacitive displacement sensors that reduce the required manufacturing precision while maintaining high-accuracy measurements. First, the effect of edge roughness of the induction electrodes is suppressed by the filtering effect of the overlapping area integral method. Second, the effect of edge roughness of the excitation electrodes can be suppressed by the smoothing effect of the electric field. Third, the averaging effect of multiple induction electrodes is adopted to reduce the effect of geometric errors in the excitation electrodes. Printed circuit board manufacturing technology with a manufacturing accuracy on the order of 10 μm is selected to fabricate a prototype time-grating capacitive sensor, and a linearity of 0.005% is obtained for a single-period range of 0.8 mm. The measurement accuracy is largely independent of the manufacturing precision owing to the three aforementioned smoothing effects, which is promising for transforming the presently challenging technology of long-range displacement measurements with nanometer-scale accuracy into a conventional technology. Autors: Kai Peng;Zhicheng Yu;Xiaokang Liu;Ziran Chen;Hongji Pu; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7377 - 7386 Publisher: IEEE
» Feedback-Based Integrated Motorway Traffic Flow Control With Delay Balancing
 Abstract:The development and deployment of simple, yet efficient, coordinated and integrated control tools for motorway traffic control remains a challenge. A generic integrated feedback-based motorway traffic flow control concept is proposed in this paper. It is based on the combination and suitable extension of control algorithms and tools proposed or deployed in other studies, such as ramp metering or variable speed limit (VSL)-enabled cascade-feedback mainstream traffic flow control, and allows for consideration of multiple bottlenecks. The new controller enables coordination of ramp metering actions at a series of on-ramps, as well as integration with VSL control actions, toward a common control goal, which is bottleneck throughput maximization. While doing this, the approach considers a pre-specified (desired) balancing of the incurred delays upstream of the employed actuators, via a suitably designed knapsack problem. Despite the multitude of the offered configurations, options, and possibilities, the generic control algorithm remains simple, efficient, and suitable for field implementation. The control algorithm is demonstrated and evaluated using a validated macroscopic traffic flow model for a number of scenarios. Autors: Georgia-Roumpini Iordanidou;Ioannis Papamichail;Claudio Roncoli;Markos Papageorgiou; Appeared in: IEEE Transactions on Intelligent Transportation Systems Publication date: Sep 2017, volume: 18, issue:9, pages: 2319 - 2329 Publisher: IEEE
» Field and Torque Calculation and Transient Analysis in Variable Reluctance Machines
 Abstract:The variable reluctance machine (VRM), also known as the switched reluctance machine, is a class of electrical machines that exhibits many interesting characteristics. However, the satisfactory analytical formulation of its working equations (torque and voltage equations) in a saturated regime is not yet completely available for covering some of its operational aspects, such as the analysis of transient state. This paper provides such equations for the general case in which a VRM operates with a pronounced level of magnetic saturation. These equations together with help of lookup tables allow online access of the instant torque on the shaft as well as the flux linkage of a phase, since the computation times are reduced to a few microseconds, whereas in a numerical approach such as the finite-element method, would take a few minutes of CPU time, which is totally inappropriate for such investigations. Autors: Bahram Amin;Moien Masoumi;Mojtaba Mirsalim; Appeared in: IEEE Transactions on Magnetics Publication date: Sep 2017, volume: 53, issue:9, pages: 1 - 9 Publisher: IEEE
» Field Modeling for Plate-Core Inductor With Significant Fringing Using Equal-Flux Contours
 Abstract:An inductor with winding sandwiched between two core plates is analyzed to model the nonuniform distribution of magnetic field. The winding is placed near the edge of the core to maximize the energy within the limited footprint such that the amount of energy stored outside the core volume is not negligible. The proportional-reluctance, equal-flux model is developed to build the contours with equal amount of flux by governing the reluctance of the flux path. The shapes of the flux lines are modeled by different functions that are guided by the finite-element simulation. The field calculated from the flux lines enables calculation of inductance, winding loss, and core loss. The inductance is used as a figure of merit to evaluate the modeling accuracy. Prototypes made of flexible circuit for inductors with different layouts are measured to verify the model. The measured inductances agree with the modeled result by less than 13% error. Autors: Han Cui;Joyce Mullenix;Roberto Massolini;Khai D. T. Ngo; Appeared in: IEEE Transactions on Magnetics Publication date: Sep 2017, volume: 53, issue:9, pages: 1 - 10 Publisher: IEEE
» Field Plate Design for Low Leakage Current in Lateral GaN Power Schottky Diodes: Role of the Pinch-off Voltage
 Abstract:In this letter, we demonstrate a general model to reduce the reverse leakage current () in high-voltage AlGaN/GaN Schottky diodes (SBDs) by engineering the pinchoff voltage () of their field plates (FPs). The maximum voltage drop at the Schottky junction () in the OFF state can be significantly decreased by reducing , which leads to a drastically diminished . We used a tri-gate architecture as means to control and, thus, , as it offers great flexibility to engineer compared with conventional schemes. of SBDs with tri-gate FPs was reduced by decreasing the width of the nanowires, which led to a very small , below 10 nA/mm under reverse biases up to 500 V, and an increase of over 800 V in soft breakdown voltage () at /mm. These results reveal the importance of in reducing ${I}_{\text {R}}$ for SBDs, and unveil the potential of tri-gate structures as FPs for power devices. Autors: Jun Ma;Dante Colao Zanuz;Elison Matioli; Appeared in: IEEE Electron Device Letters Publication date: Sep 2017, volume: 38, issue:9, pages: 1298 - 1301 Publisher: IEEE
 Abstract:Ericsson's The 5G Business Potential report [1] analyzes commercial potential offered by fifth-generation (5G) industrial technology, focusing on eight key global industries including manufacturing, public safety, financial services, health care, automotive, public transport, media and entertainment, and energy utilities. Ericsson has identified a huge opportunity for telecom operators who address industry digitalization, and they foresee a revenue potential of US\$582 billion by 2026. Compared to 2016, this represents a 34% growth in revenue. The report shows that the manufacturing and energy utilities sectors offer the strongest opportunity for revenues created or enhanced by 5G. Autors: Matthias Pätzold; Appeared in: IEEE Vehicular Technology Magazine Publication date: Sep 2017, volume: 12, issue:3, pages: 4 - 11 Publisher: IEEE
» Finding all the Lower Boundary Points in a Multistate Two-Terminal Network
 Abstract:System reliability of a multistate flow network can be computed in terms of all the lower boundary points, called d-minimal paths (-MPs). Although several algorithms have been proposed in the literature for the -MP problem, there is still room for improvement upon its solution. Here, some new results are presented to improve the solution of the problem. A simple novel algorithm is improved to solve a Diophantine system that appeared in the -MP problem. Then, an improved algorithm is proposed for the -MP problem. It is also explained how the proposed algorithm can be used in order to assess the reliability of some smart grid communication networks. We provide the complexity results and show the main algorithm to be more efficient than the existing ones in terms of execution times through some benchmark networks and a general network example. Moreover, we compare the algorithms through one thousand randomly generated test problems using the Dolan and Moré's performance profile. Autors: Majid Forghani-elahabad;Luiz Henrique Bonani; Appeared in: IEEE Transactions on Reliability Publication date: Sep 2017, volume: 66, issue:3, pages: 677 - 688 Publisher: IEEE
» Finding Related Forum Posts through Content Similarity over Intention-Based Segmentation
 Abstract:We study the problem of finding related forum posts to a post at hand. In contrast to traditional approaches for finding related documents that perform content comparisons across the content of the posts as a whole, we consider each post as a set of segments, each written with a different goal in mind. We advocate that the relatedness between two posts should be based on the similarity of their respective segments that are intended for the same goal, i.e., are conveying the same intention. This means that it is possible for the same terms to weigh differently in the relatedness score depending on the intention of the segment in which they are found. We have developed a segmentation method that by monitoring a number of text features can identify the parts of a post where significant jumps occur indicating a point where a segmentation should take place. The generated segments of all the posts are clustered to form intention clusters and then similarities across the posts are calculated through similarities across segments with the same intention. We experimentally illustrate the effectiveness and efficiency of our segmentation method and our overall approach of finding related forum posts. Autors: Dimitra Papadimitriou;Georgia Koutrika;Yannis Velegrakis;John Mylopoulos; Appeared in: IEEE Transactions on Knowledge and Data Engineering Publication date: Sep 2017, volume: 29, issue:9, pages: 1860 - 1873 Publisher: IEEE
» Finite-Horizon Energy-Efficient Scheduling With Energy Harvesting Transmitters Over Fading Channels
 Abstract:In this paper, energy-efficient transmission schemes achieving maximal throughput over a finite time interval are studied in a problem setting, including energy harvests, data arrivals, and channel variation. The goal is to express the offline optimal policy in a way that facilitates a good online solution. We express any throughput maximizing energy-efficient offline schedule (EE-TM-OFF) explicitly in terms of water levels. This allows per-slot real-time evaluation of transmit power and rate decisions, using estimates of the associated offline water levels. To compute the online power level, we construct a stochastic dynamic program that incorporates the offline optimal solution as a stochastic process. We introduce the immediate fill measure, which provides a lower bound on the efficiency of any online policy with respect to the corresponding optimal offline solution. The online algorithms obtained this way exhibit performance close to the offline optimal, not only in the long run but also in short problem horizons, deeming them suitable for practical implementations. Autors: Baran Tan Bacinoglu;Elif Uysal-Biyikoglu;Can Emre Koksal; Appeared in: IEEE Transactions on Wireless Communications Publication date: Sep 2017, volume: 16, issue:9, pages: 6105 - 6118 Publisher: IEEE
» First-Principles Investigations of TiGe/Ge Interface and Recipes to Reduce the Contact Resistance
 Abstract:The metal–semiconductor interface is fundamental to any semiconductor device and the success of advanced technology nodes critically depends upon the minimization of the contact resistance at the interface. In this paper, we calculate the electronic structure of a metal–semiconductor interface (TiGe/Ge contact) within the framework of first-principles density functional theory simulations. We report the modulation of the Schottky barrier height with respect to the different phases of TiGe metal and different crystallographic orientations of Ge substrate. We further compute the – characteristics of the TiGe/Ge contact with nonequilibrium Green’s function formalism, using a two-terminal device configuration. The calculated transmission spectrum allows us to extract the contact resistance at the metal–semiconductor interface. Furthermore, the onset of Ohmic contact for p-doped TiGe/Ge interface is identified by studying the – characteristics as a function of increasing active carrier concentration. We find that a doping concentration of 1e21 is sufficient to transform the Schottky contact into Ohmic and thereby achieve a least possible contact resistance at the interfaces. Our paper thus provides useful physical insights into the nanoscale details of the TiGe/Ge interfaces and can guide further process development to minimize the contact resistance. Autors: Hemant Dixit;Chengyu Niu;Mark Raymond;Vimal Kamineni;Rajan K. Pandey;Anirudhha Konar;Jody Fronheiser;Adra V. Carr;Phil Oldiges;Praneet Adusumilli;Nicholas A. Lanzillo;Xin Miao;Bhagawan Sahu;Francis Benistant; Appeared in: IEEE Transactions on Electron Devices Publication date: Sep 2017, volume: 64, issue:9, pages: 3775 - 3780 Publisher: IEEE
» Flexibility Needed: Challenges for Future Energy Storage Systems [Guest Editorial]
 Abstract:The articles in this special section focus on the technologies that will support future energy storage systems. In modern power systems, we are transitioning to an increasing penetration of massive low-cost wind and solar generation, which will require indispensable system flexibility for balancing requirements to maintain system performance. The existing actors have limited technical capabilities to provide the needed flexibility, and new alternatives are required. The flexibility providers are diverse and being assessed extensively, with a clear sense of urgency. Autors: Hugh Rudnick;Luiz Barroso; Appeared in: IEEE Power and Energy Magazine Publication date: Sep 2017, volume: 15, issue:5, pages: 12 - 19 Publisher: IEEE
» Flexible PCC Voltage Unbalance Compensation Strategy for Autonomous Operation of Parallel DFIGs
 Abstract:This paper proposes a flexible compensation strategy for parallel-connected doubly fed induction generators (DFIGs) when connected to an unbalanced weak grid. The proposed strategy has two main advantages, the voltage unbalance factor at the point of common coupling (PCC) can be continuously controlled, thus, the flexible tradeoff between the balanced DFIG output current and the balanced PCC voltage can be achieved, and the negative sequence current required by the compensation can be properly shared among the parallel DFIGs and their grid side converters according to their respective operation conditions without the need of real-time communication. The operation performance and stability of the proposed strategy are analyzed. Simulation and experimental results are carried out to verify the proposed compensation strategy. Autors: Tao Wang;Heng Nian;Z. Q. Zhu;Hongyang Huang;Xiaoming Huang; Appeared in: IEEE Transactions on Industry Applications Publication date: Sep 2017, volume: 53, issue:5, pages: 4807 - 4820 Publisher: IEEE
» Flexible Power Regulation and Current-Limited Control of the Grid-Connected Inverter Under Unbalanced Grid Voltage Faults
 Abstract:The grid-connected inverters may experience excessive current stress in case of unbalanced grid voltage fault ride through (FRT), which significantly affects the reliability of the power supply system. In order to solve the problem, the inherent mechanisms of the excessive current phenomenon with the conventional FRT solutions are discussed. The quantitative analysis of three-phase current peak values is conducted and a novel current-limited control strategy is proposed to achieve the flexible active and reactive power regulation and successful FRT in a safe current operation area with the aim of improving the system reliability under grid faults. Finally, the simulation and experiments of traditional and proposed FRT solutions are carried out. The results verify the effectiveness of the proposed method. Autors: Xiaoqiang Guo;Wenzhao Liu;Zhigang Lu; Appeared in: IEEE Transactions on Industrial Electronics Publication date: Sep 2017, volume: 64, issue:9, pages: 7425 - 7432 Publisher: IEEE
» Fly the electric skies
 Abstract:When you first sit in the cockpit of an electric-powered airplane, you see nothing out of the ordinary. However, touch the Start button and it strikes you immediately: an eerie silence. There is no roar, no engine vibration, just the hum of electricity and the soft whoosh of the propeller. You can converse easily with the person in the next seat, without headphones. The silence is a boon to both those in the cockpit and those on the ground below. Autors: George Bye; Appeared in: IEEE Spectrum Publication date: Sep 2017, volume: 54, issue:9, pages: 26 - 31 Publisher: IEEE
» Flying cell towers to the rescue
 Abstract:YOU'VE JUST SETTLED DOWN on the couch when a sudden jolt rattles you so hard that you spill hot coffee in your lap. The walls of your home split and collapse, pinning you beneath a section of roofing. Then the motion stops. Heart pounding, you reach for the smartphone in your pocket, but when you try to call for help, there’s no service. Because the earthquake has demolished the nearest cell tower, first responders are forced to rely on outdated radios and networks as they search the rubble for survivors. The devices carried by police officers can't communicate with those used by firefighters. Walkie-talkies work only at short range. No wonder several homes are searched twice while yours is overlooked. Autors: Kamesh Namuduri; Appeared in: IEEE Spectrum Publication date: Sep 2017, volume: 54, issue:9, pages: 38 - 43 Publisher: IEEE
» Fog Vehicular Computing: Augmentation of Fog Computing Using Vehicular Cloud Computing
 Abstract:Fog computing has emerged as a promising solution for accommodating the surge of mobile traffic and reducing latency, both known to be inherent problems of cloud computing. Fog services, including computation, storage, and networking, are hosted in the vicinity of end users (edge of the network), and, as a result, reliable access is provisioned to delay-sensitive mobile applications. However, in some cases, the fog computing capacity is overwhelmed by the growing number of demands from patrons, particularly during peak hours, and this can subsequently result in acute performance degradation. In this article, we address this problem by proposing a new concept called fog vehicular computing (FVC) to augment the computation and storage power of fog computing. We also design a comprehensive architecture for FVC and present a number of salient applications. The result of implementation clearly shows the effectiveness of the proposed architecture. Finally, some open issues and envisioned directions are discussed for future research in the context of FVC. Autors: Mehdi Sookhak;F. Richard Yu;Ying He;Hamid Talebian;Nader Sohrabi Safa;Nan Zhao;Muhammad Khurram Khan;Neeraj Kumar; Appeared in: IEEE Vehicular Technology Magazine Publication date: Sep 2017, volume: 12, issue:3, pages: 55 - 64 Publisher: IEEE
» Food Intake Detection Using Ultrasonic Doppler Sonar
 Abstract:Reliable, user-friendly and convenient sensing is highly desirable when the continuous monitoring of food intake is necessary. In this paper, food intake monitoring was during the processes of chewing and swallowing. Acoustic Doppler sonar (ADS) detected chewing and swallowing events that were non-contact and free from acoustic interference. When a 40 kHz ultrasonic beam was focused on the lower jaw and neck, movements of the chin and neck cause Doppler frequency shifts and an amplitude envelope modulation of ultrasonic signals. Hence, it was possible to detect chewing and swallowing events using Doppler frequency shifts in the received ultrasound signals. To prevent suspicious chew events caused by talking from being recognized as food intake events, the log-filter bank energy of the voice band was also taken into consideration. Automatic detection of chewing and swallowing events was achieved via an artificial neural network. The experimental results showed that the proposed ADS-based food intake detection method yielded promising results with maximum recognition rates of 91.4% and 78.4% for chewing and swallowing, respectively. As a result, it was confirmed that the proposed food intake detection method using ultrasonic Doppler yielded high rates of recognition without discomfort to the user from continuous skin contact. Autors: Ki-Seung Lee; Appeared in: IEEE Sensors Journal Publication date: Sep 2017, volume: 17, issue:18, pages: 6056 - 6068 Publisher: IEEE

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