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Electrical and Computer Engineering Faculty Research & Creative Works

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Q-Learning Based Dynamic Voltage Scaling For Designs With Graceful Degradation, Yu Guang Chen, Wan Yu Wen, Tao Wang, Yiyu Shi, Shih Chieh Chang Mar 2015

Q-Learning Based Dynamic Voltage Scaling For Designs With Graceful Degradation, Yu Guang Chen, Wan Yu Wen, Tao Wang, Yiyu Shi, Shih Chieh Chang

Electrical and Computer Engineering Faculty Research & Creative Works

Dynamic voltage scaling (DVS) has been widely used to suppress power consumption in modern designs. The decision of optimal operating voltage at runtime should consider the variations in workload, process as well as environment. As these variations are hard to predict accurately at design time, various reinforcement learning based DVS schemes have been proposed in the literature. However, none of them can be readily applied to designs with graceful degradation, where timing errors are allowed with bounded probability to trade for further power reduction. In this paper, we propose a Q-learning based DVS scheme dedicated to the designs with graceful …

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Low-Complexity Soft-Interference Cancellation Turbo Equalisation For Multi-Input-Multi-Output Systems With Multilevel Modulations, Jingxian Wu, Longbao Wang, Chengshan Xiao Mar 2015

Low-Complexity Soft-Interference Cancellation Turbo Equalisation For Multi-Input-Multi-Output Systems With Multilevel Modulations, Jingxian Wu, Longbao Wang, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

This study presents a low-complexity soft-interference cancellation equalizer (SICE) for the turbo detection of multiple-input-multiple-output systems operating in time dispersive channels. The SICE contains three time-invariant linear filters: a feedforward filter, a causal feedback filter and an anti-causal feedback filter. The feedforward filter is designed to suppress the InterSymbol interference because of channel time dispersion and the multiplexing interference from multiple transmit antennas. The causal (or anti-causal) feedback filter is developed to remove the residual interference caused by the symbols transmitted before (or after) the symbol under detection. The filters are designed by analyzing the statistical properties of soft decisions. …

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Accuracy Enhancement Of The Equivalence Principle Algorithm Based On The Meshless Spherical Surface, Xin Fu, Lijun Jiang, Zuhui Ma Mar 2015

Accuracy Enhancement Of The Equivalence Principle Algorithm Based On The Meshless Spherical Surface, Xin Fu, Lijun Jiang, Zuhui Ma

Electrical and Computer Engineering Faculty Research & Creative Works

Conventional equivalence principle algorithm (EPA) employs cubical boxes to support equivalence sources. However, it introduces strong discontinuities. In this work, a spherical surface is employed as the equivalence surface in EPA to avoid singularities from non-smooth surfaces. Further to achieve high order accuracy, meshless samples are used for the integrals on the spherical surface to avoid the equivalence surface mesh discretization. Theoretically the accuracy of EPA can be significantly improved, which was further benchmarked though numerical examples. Various meshless schemes are also discussed to achieve the optimal solution based on the spherical equivalence surface.

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The Fast Solver For Calculating The High Frequency Scattered Field From The Fock Current On The Surface Of The 3-D Convex Scatterer, Yu Mao Wu, Weng Cho Chew, Li (Lijun) Jun Jiang Mar 2015

The Fast Solver For Calculating The High Frequency Scattered Field From The Fock Current On The Surface Of The 3-D Convex Scatterer, Yu Mao Wu, Weng Cho Chew, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we first consider the Fock current from the 3-D convex cylinder. Next, on invoking the incremental length diffraction technique (ILDC), the resultant high frequency scattered fields are expressed in terms of the Fock current. We propose the NSDP method to calculate these scattered fields. Numerical examples illustrate that the proposed NSDP method for calculating the high frequency scattered fields could achieve the frequency independent computational workload and error controllable accuracy.

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A Study Of Decision Process In Mcdm Problems With Large Number Of Criteria, Jian Liu, Peng Liu, Si Feng Liu, Xian Zhong Zhou, Tao Zhang Mar 2015

A Study Of Decision Process In Mcdm Problems With Large Number Of Criteria, Jian Liu, Peng Liu, Si Feng Liu, Xian Zhong Zhou, Tao Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an effective decision process method is proposed to address the challenge in a multiple criteria decision-making (MCDM) problem because of large number of criteria. This method is based on the criteria reduction, tolerance relation, and prospect theory (PT). By building a discernibility matrix for tolerance relation (DMTR) in an MCDM problem with numerical values or interval numbers, this method first allows us to recognize a set of critical criteria from a large criteria pool and ignore the other criteria. Next, it establishes the criteria weights through the DMTR as they are usually not indicated in the data. …

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Generalized Coupled-Line All-Pass Phasers, Shulabh Gupta, Qingfeng Zhang, Lianfeng Zou, Li (Lijun) Jun Jiang, Christophe Caloz Mar 2015

Generalized Coupled-Line All-Pass Phasers, Shulabh Gupta, Qingfeng Zhang, Lianfeng Zou, Li (Lijun) Jun Jiang, Christophe Caloz

Electrical and Computer Engineering Faculty Research & Creative Works

Generalized coupled-line all-pass phasers, based on cascaded C-sections (CCSs), cascaded coupled-lines (CCLs), and hybrid-cascaded (HC) coupled transmission-line sections, are presented and demonstrated using analytical, full-wave, and experimental results. It is shown that for N commensurate coupled-line sections, CCL and HC phasers exhibit N group-delay peaks per coupled-line section harmonic frequency band, in contrast to the CCS configuration, which exhibits only one peak within this band. It is also shown that for a given maximum achievable coupling-coefficient, the HC configuration provides the largest group-delay swing. A wave-interference analysis is finally applied to the various coupled-line phasers, explaining their unique group-delay characteristics …

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Using Social Sensors For Influence Propagation In Networks With Positive And Negative Relationships, Basak Guler, Burak Varan, Kaya Tutuncuoglu, Mohamed Nafea, Ahmed A. Zewail, Aylin Yener, Damien Octeau Mar 2015

Using Social Sensors For Influence Propagation In Networks With Positive And Negative Relationships, Basak Guler, Burak Varan, Kaya Tutuncuoglu, Mohamed Nafea, Ahmed A. Zewail, Aylin Yener, Damien Octeau

Electrical and Computer Engineering Faculty Research & Creative Works

Online social communities often exhibit complex relationship structures, ranging from close friends to political rivals. As a result, persons are influenced by their friends and foes differently. Future network applications can benefit from integrating these structural differences in propagation schemes through socially aware sensors. In this paper, we introduce a propagation model for such social sensor networks with positive and negative relationship types. We tackle two main scenarios based on this model. The first one is to minimize the end-to-end propagation cost of influencing a target person in favor of an idea by utilizing sensor observations about the relationship types …

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Cooperative Multi-Cell Mimo Downlink Precoding With Finite-Alphabet Inputs, Wenhao Wu, Kun Wang, Weiliang Zeng, Zhi Ding, Chengshan Xiao Mar 2015

Cooperative Multi-Cell Mimo Downlink Precoding With Finite-Alphabet Inputs, Wenhao Wu, Kun Wang, Weiliang Zeng, Zhi Ding, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

This work investigates the design of linear precoders in cooperative multi-cell MIMO downlink coverage for finite-alphabet source signals. Traditional design of multi-cell MIMO downlink precoder relies on Gaussian input assumption, which may lead to performance loss when true data inputs consist of discrete non-Gaussian symbols. This work presents optimized precoders for finite-alphabet input by maximizing the sum rate under per-base station power constraints. Specifically, we propose two distributed algorithms: a finite-alphabet signal Gaussian interference gradient projection algorithm and a block diagonalization alternating optimization algorithm while supporting interference cancellation. Our numerical results demonstrate considerable performance gain in terms of approximate transmission …

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Fabrication And Characterization Of Single Crystalline 4h-Sic Mems Devices With N-P-N Homoepitaxial Structure, Feng Zhao, Allen V. Lim Feb 2015

Fabrication And Characterization Of Single Crystalline 4h-Sic Mems Devices With N-P-N Homoepitaxial Structure, Feng Zhao, Allen V. Lim

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reports single crystalline 4H-SiC MEMS with homoepitaxial n-p-n structure and its resonant characteristics under electrostatic actuation. Single crystalline fully exploits the superior material properties of SiC for operations in harsh environments. Compared to previously report p-n structure, the n-p-n structure makes electrostatic actuation applicable which is essentially important for applications of resonators and actuators to sensor devices. Such n-p-n structure, complementing the p-n structure, also further extends the capability of monolithic integration between SiC MEMS and electronic devices and circuits with not only p-n configurations such as diodes, but also n-p-n configurations such as BJTs and MOSFETs, etc.

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Graphene Plasmonics For Tuning Photon Decay Rate Near Metallic Split-Ring Resonator In A Multilayered Substrate, Yongpin P. Chen, Wei E.I. Sha, Lijun Jiang, Jun Hu Feb 2015

Graphene Plasmonics For Tuning Photon Decay Rate Near Metallic Split-Ring Resonator In A Multilayered Substrate, Yongpin P. Chen, Wei E.I. Sha, Lijun Jiang, Jun Hu

Electrical and Computer Engineering Faculty Research & Creative Works

Study of photon decay rate is essential to various optical devices, where graphene is an emerging building block due to its electrical tunability. In this paper, we study photon decay rate of a quantum emitter near a metallic split-ring resonator, which is embedded in a multilayered substrate incorporating a graphene layer. Analyzing photon decay rate in such a complex multilayered system is not only computationally challenging but also highly important to experimentally realizable devices. First, the dispersion relation of graphene plasmonics supported at a dieletric/graphene/dielectric structure is investigated systematically. Meanwhile, the dispersion relation of metallic plasmonics supported at a dielectric/metal …

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Systems, Methods And Devices For Vector Control Of Permanent Magnet Synchronous Machines Using Artificial Neural Networks, Shuhui Li, Michael Fairbank, Xingang Fu, Donald C. Wunsch, Eduardo Alonso Feb 2015

Systems, Methods And Devices For Vector Control Of Permanent Magnet Synchronous Machines Using Artificial Neural Networks, Shuhui Li, Michael Fairbank, Xingang Fu, Donald C. Wunsch, Eduardo Alonso

Electrical and Computer Engineering Faculty Research & Creative Works

An example method for controlling an AC electrical machine can include providing a PWM converter operably connected between an electrical power source and the AC electrical machine and providing a neural network vector control system operably connected to the PWM converter. The control system can include a current-loop neural network configured to receive a plurality of inputs. The current-loop neural network can be configured to optimize the compensating dq-control voltage. The inputs can be d- and q-axis currents, d- and q-axis error signals, predicted d- and q-axis current signals, and a feedback compensating dq-control voltage. The d- and q-axis error …

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Counter-Doped Jte, An Edge Termination For Hv Sic Devices With Increased Tolerance To The Surface Charge, Chih Fang Huang, Hua Chih Hsu, Kuan Wei Chu, Li Heng Lee, Ming Jinn Tsai, Kung Yen Lee, Feng Zhao Feb 2015

Counter-Doped Jte, An Edge Termination For Hv Sic Devices With Increased Tolerance To The Surface Charge, Chih Fang Huang, Hua Chih Hsu, Kuan Wei Chu, Li Heng Lee, Ming Jinn Tsai, Kung Yen Lee, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a comparison of different techniques for SiC high-voltage devices is performed using numerical simulations. In particular, the method of counter doping (CD) introduced in the junction termination extension (JTE) region to create a multizone termination effect is investigated. Simulation shows that compared with the other edge termination techniques, CD-JTE greatly reduces the sensitivity of breakdown voltage (BV) to JTE doses and surface charges. The multizone CD-JTE with outer rings shows that for a 30-μm thick epi-layer, 90% of the theoretical BV is achievable with a wide tolerance of 11 x 1012 cm2 to the JTE …

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Orientation Error Analysis And Compenstation Of Orthogonal Array With Two-Dimension Vector Sensors, Peng Han, Chao Ren, Zhongge Zhang, Grant L. Steven Jan 2015

Orientation Error Analysis And Compenstation Of Orthogonal Array With Two-Dimension Vector Sensors, Peng Han, Chao Ren, Zhongge Zhang, Grant L. Steven

Electrical and Computer Engineering Faculty Research & Creative Works

In the application of underwater target orientation using two-dimensional differential pressure vector sensors, both the elements of the vector sensors and the compensation algorithm will introduce target orientation errors. In this paper, simulation results of these target orientation errors reveal that channel response inconsistency errors contribute much more influence on the orthogonal array compared with the SNR, the target incident angle, and the unit location displacement. Based on this observation, a compensation algorithm for orientation estimation error is proposed and testing results demonstrate the efficiency of the proposed algorithm.

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Real Time Anomaly Detection In Wide Area Monitoring Of Smart Grids, Jie Wu, Jinjun Xiong, Prasenjit Shil, Yiyu Shi Jan 2015

Real Time Anomaly Detection In Wide Area Monitoring Of Smart Grids, Jie Wu, Jinjun Xiong, Prasenjit Shil, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

The real time anomaly detection in wide area monitoring of smart grids is critical to enhance the reliability of power systems. However, capturing the features of anomalous interruption and then detecting them at real time is difficult for large-scale smart grids, because the measurement data volume and complexity increases drastically with the exponential growth of data from the immense intelligent monitoring devices to be rolled out and the need for fast information retrieval from those mass data. Most of existing anomaly detection methods fail to handle it well. This paper proposes a spatial-Temporal correlation based anomalous behavior model to capture …

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Random Walk Based Capacitance Extraction For 3d Ics With Cylindrical Inter-Tier-Vias, Wenjian Yu, Chao Zhang, Qing Wang, Yiyu Shi Jan 2015

Random Walk Based Capacitance Extraction For 3d Ics With Cylindrical Inter-Tier-Vias, Wenjian Yu, Chao Zhang, Qing Wang, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Three-dimensional integrated circuits (3D ICs) make use of the vertical dimension for smaller footprint, higher speed, lower power consumption, and better timing performance. In 3D ICs, the inter-tier-via (ITV) is a critical enabling technique because it forms vertical signal and power paths. Accordingly, it is imperative to accurately and efficiently extract the electrostatic capacitances of ITVs using field solvers. Unfortunately, the cylindrical via shape presents major challenges to most of the existing methods. To address this issue, we develop a novel floating random walk (FRW) method by rotating the transition cube to suit the cylindrical surface and devising a special …

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Opportunistic Through-Silicon-Via Inductor Utilization In Lc Resonant Clocks: Concept And Algorithms, Umamaheswara Rao Tida, Varun Mittapalli, Cheng Zhuo, Yiyu Shi Jan 2015

Opportunistic Through-Silicon-Via Inductor Utilization In Lc Resonant Clocks: Concept And Algorithms, Umamaheswara Rao Tida, Varun Mittapalli, Cheng Zhuo, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

LC resonant clock is an attracting option for low power on-chip clock distribution designs. However, a major limiting factor to its implementation is the large area overhead due to the conventional spiral inductors. On the other hand, idle through-silicon-vias (TSVs) in three-dimensional integrated circuits (3D ICs) can form vertical inductors with minimal footprint and little noise coupling with horizontal traces, particularly suitable for the application of LC resonant clock. However, due to the strict constraints on the location of idle TSVs, the use of the TSV inductor is limited by the constrained choices of its location, inductance and quality factor. …

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Fast And Accurate Emissivity And Absolute Temperature Maps Measurement For Integrated Circuits, Hsueh Ling Yu, Yih Lang Li, Tzu Yi Liao, Tianchen Wang, Yiyu Shi Jan 2015

Fast And Accurate Emissivity And Absolute Temperature Maps Measurement For Integrated Circuits, Hsueh Ling Yu, Yih Lang Li, Tzu Yi Liao, Tianchen Wang, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

The comparison of temperatures (temperature correlation) obtained by measuring instruments and by thermal simulation is commonly necessary. Currently the way in which thermal maps are obtained by infrared thermographer yields inaccurate results since the emissivity values of all elements in an IC are ignored and measurement method assumes a constant emissivity. Without the correct settings of emissivity in infrared thermographer, the temperature variation could reach up to as high as 300 %. Coating black paint on the IC surface is a widely used method to assume the IC with constant emissivity and simplify the measurement procedures. Coating a uniform black …

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Sensing Performance Study Of Sic, A Wide Bandgap Semiconductor Material Platform For Surface Plasmon Resonance Sensor, Wei Du, Feng Zhao Jan 2015

Sensing Performance Study Of Sic, A Wide Bandgap Semiconductor Material Platform For Surface Plasmon Resonance Sensor, Wei Du, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

The sensing properties of a surface plasmon resonance (SPR) based waveguide sensor on a wide bandgap semiconductor, silicon carbide (SiC), were studied. Compared to other waveguide sensors, the large bandgap energy of SiC material allows the sensor to operate in the visible and near infrared wavelength range, while the SPR effect by a thin gold film is expected to improve the sensitivity. The confinement factor of the sensor at various wavelengths of the incident light and refractive index of the analyte were investigated using an effective index method. Since the change of analyte type and concentration is reflected by the …

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Mode-Multiplexed Transmission Over Conventional Graded-Index Multimode Fibers, Roland Ryf, Nicolas K. Fontaine, H. Chen, B. Guan, B. Huang, Mina Esmaeelpour Jan 2015

Mode-Multiplexed Transmission Over Conventional Graded-Index Multimode Fibers, Roland Ryf, Nicolas K. Fontaine, H. Chen, B. Guan, B. Huang, Mina Esmaeelpour

Electrical and Computer Engineering Faculty Research & Creative Works

We present experimental results for combined mode-multiplexed and wavelength multiplexed transmission over conventional graded-index multimode fibers. We use mode-selective photonic lanterns as mode couplers to precisely excite a subset of the modes of the multimode fiber and additionally to compensate for the differential group delay between the excited modes. Spatial mode filters are added to suppress undesired higher order modes. We transmit 30-Gbaud QPSK signals over 60 WDM channels, 3 spatial modes, and 2 polarizations, reaching a distance of 310 km based on a 44.3 km long span. We also report about transmission experiments over 6 spatial modes for a …

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Teaching Engineering Ethics, Steve Eugene Watkins Jan 2015

Teaching Engineering Ethics, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

Instruction in engineering ethics is an important aspect of professional development. For universities, it is an element of program assessment and is considered for accreditation. For engineering students, it addresses relationships in professional life and is a topic for professional licensure. A common instructional objective is for students to have an ability to continue developing their ethical knowledge and judgment. Topical content typically includes an introduction to principles of applied ethics with supporting examples of related engineering situations. This paper discusses the organization of the ethics component in a senior seminar course. Key topics are ethics principles in the context …

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Big Data -- A 21st Century Science Maginot Line? No-Boundary Thinking: Shifting From The Big Data Paradigm, Xiuzhen Huang, Steven F. Jennings, Barry Bruce, Alison Buchan, Liming Cai, Pengyin Chen, Carole Cramer, Weihua Guan, Uwe Kk Hilgert, Hongmei Jiang, Zenglu Li, Gail Mcclure, Donald F. Mcmullen, Bindu Nanduri, Andy Perkins, Bhanu Rekepalli, Saeed Salem, Jennifer Specker, Karl Walker, Donald C. Wunsch, Donghai Xiong, Shuzhong Zhang, Yu Zhang, Zhongming Zhao, Jason H. Moore Jan 2015

Big Data -- A 21st Century Science Maginot Line? No-Boundary Thinking: Shifting From The Big Data Paradigm, Xiuzhen Huang, Steven F. Jennings, Barry Bruce, Alison Buchan, Liming Cai, Pengyin Chen, Carole Cramer, Weihua Guan, Uwe Kk Hilgert, Hongmei Jiang, Zenglu Li, Gail Mcclure, Donald F. Mcmullen, Bindu Nanduri, Andy Perkins, Bhanu Rekepalli, Saeed Salem, Jennifer Specker, Karl Walker, Donald C. Wunsch, Donghai Xiong, Shuzhong Zhang, Yu Zhang, Zhongming Zhao, Jason H. Moore

Electrical and Computer Engineering Faculty Research & Creative Works

Whether your interests lie in scientific arenas, the corporate world, or in government, you have certainly heard the praises of big data: Big data will give you new insights, allow you to become more efficient, and/or will solve your problems. While big data has had some outstanding successes, many are now beginning to see that it is not the Silver Bullet that it has been touted to be. Here our main concern is the overall impact of big data; the current manifestation of big data is constructing a Maginot Line in science in the 21st century. Big data is not …

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Future Internet Resilience For Massive Failures, Yufei Cheng, Egemen K. Çetinkaya, James P. G. Sterbenz Jan 2015

Future Internet Resilience For Massive Failures, Yufei Cheng, Egemen K. Çetinkaya, James P. G. Sterbenz

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Network Attack Experimentation Using Openflow-Enabled Geni Testbed, Mani Chaitanya Gorla, Venu Madhav Kamaraju, Egemen K. Çetinkaya Jan 2015

Network Attack Experimentation Using Openflow-Enabled Geni Testbed, Mani Chaitanya Gorla, Venu Madhav Kamaraju, Egemen K. Çetinkaya

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Thevenin Equivalence In Disorderless Quantum Networks, C. A. Cain, Cheng-Hsiao Wu Jan 2015

Thevenin Equivalence In Disorderless Quantum Networks, C. A. Cain, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

We outline the procedure of extending the Thévenin equivalence principle for classical electric circuits to reducing Aharonov-Bohm-based quantum networks into equivalent models. With examples, we show from first principles how the requirements are related to the electron band structure's Fermi level and the lattice spacing of the network. Quantum networks of varying degrees of coupling strength from four basic classifications of single and double entangled loops sharing symmetry and highly correlated band structures are used to demonstrate the concept. We show the limitations of how the principle may be applied. Several classes of examples are given and their equivalent forms …

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Low Complexity Polynomial Expansion Detector For Massive Mimo Uplink With Multiple-Antenna Users, An An Lu, Xiqi Gao, Chengshan Xiao Jan 2015

Low Complexity Polynomial Expansion Detector For Massive Mimo Uplink With Multiple-Antenna Users, An An Lu, Xiqi Gao, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a low complexity polynomial expansion (PE) detector for massive multi-input multi-output (MIMO) uplink transmissions is proposed. In contrast to most massive MIMO systems in the literature, where single-antenna user equipment's (UEs) are assumed, multiple-antenna UEs are employed in this paper. Furthermore, each link between a user and the base station forms a jointly correlated Rician fading channel. The PE detector reduces the complexity of the minimum mean square error (MMSE) detector by replacing the matrix inversion with an approximate matrix polynomial. In the design of the low complexity PE detector, the approximations of the moments of the …

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An Efficient Linear Precoding Algorithm For Energy Harvesting Transmitter With Finite-Alphabet Inputs And Instantaneous Csi, Xiaodong Zhu, Weiliang Zeng, Chengshan Xiao Jan 2015

An Efficient Linear Precoding Algorithm For Energy Harvesting Transmitter With Finite-Alphabet Inputs And Instantaneous Csi, Xiaodong Zhu, Weiliang Zeng, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

This paper investigates the precoder design in multiple-input multiple-output (MIMO) systems with energy harvester. The objective is to maximize the sum of mutual information (MI) over multiple time slots with causal knowledge of energy arrivals. Different from existing works, the system is considered with finite-alphabet inputs, and the transmitter is assumed to know not only the statistical channel state information (CSI) but also the instantaneous CSI of the current time slot at the beginning of each time slot. The optimal precoder design leads to an intractable multi- dimensional matrix optimization problem. We show that this difficult optimization problem can be …

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Investigation Of Thermoelectric Properties Of P-Type Gan Thin Films, Bahadir Kucukgok, Babar Hussain, Chuanle Zhou, Ian T. Ferguson, Na Lu Jan 2015

Investigation Of Thermoelectric Properties Of P-Type Gan Thin Films, Bahadir Kucukgok, Babar Hussain, Chuanle Zhou, Ian T. Ferguson, Na Lu

Electrical and Computer Engineering Faculty Research & Creative Works

GaN and its alloys are promising candidates for high temperature thermoelectric (TE) materials due to their high Seebeck coefficient and high thermal and mechanical stability. Moreover, these materials can overcome the toxicity concern of current Te-based TE materials, such as BI2Te3 and PbTe. These materials have recently shown a higher Seebeck coefficient than that of SiGe in high temperature region because their large bandgap characteristic eliminates the bipolar conduction. In this study, we report the room temperature thermoelectric properties of p-type Mg doped GaN, grown by metalorganic chemical vapor deposition (MOCVD) on sapphire substrate with various carrier …

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Real Time Mission Planning, Emad William Saad, Stefan Richard Bieniawski, Riley Pigg, Paul Edward, John Lyle Vian, Paul Michael Robinette, Donald C. Wunsch Jan 2015

Real Time Mission Planning, Emad William Saad, Stefan Richard Bieniawski, Riley Pigg, Paul Edward, John Lyle Vian, Paul Michael Robinette, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

The different advantageous embodiments provide a system comprising a number of computers, a graphical user interface, first program code stored on the computer, and second program code stored on the computer. The graphical user interface is executed by a computer in the number of computers. The computer is configured to run the first program code to define a mission using a number of mission elements. The computer is configured to run the second program code to generate instructions for a number of assets to execute the mission and monitor the number of assets during execution of the mission.

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Survivability Evaluation Of Gas, Water And Electricity Infrastructures, Alberto A. Avritzer, Laura Carnevali, Hamed Ghasemieh, Lucia Happe, Boudewijn R. H. M. Haverkort, Anne Koziolek, Daniel Sadoc Menasche, Anne Remke, Sahra Sedigh, Enrico Vicario Jan 2015

Survivability Evaluation Of Gas, Water And Electricity Infrastructures, Alberto A. Avritzer, Laura Carnevali, Hamed Ghasemieh, Lucia Happe, Boudewijn R. H. M. Haverkort, Anne Koziolek, Daniel Sadoc Menasche, Anne Remke, Sahra Sedigh, Enrico Vicario

Electrical and Computer Engineering Faculty Research & Creative Works

The infrastructures used in cities to supply power, water and gas are consistently becoming more automated. As society depends critically on these cyber-physical infrastructures, their survivability assessment deserves more attention. In this overview, we first touch upon a taxonomy on survivability of cyber-physical infrastructures, before we focus on three classes of infrastructures (gas, water and electricity) and discuss recent modelling and evaluation approaches and challenges.

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Efficient Calculation Of Large Finite Periodic Structures Based On Surface Wave Analysis, Xiaoyan Y.Z. Xiong, Ling Ling Meng, Li (Lijun) Jun Jiang, Wei E.I. Sha, Fan Yang Jan 2015

Efficient Calculation Of Large Finite Periodic Structures Based On Surface Wave Analysis, Xiaoyan Y.Z. Xiong, Ling Ling Meng, Li (Lijun) Jun Jiang, Wei E.I. Sha, Fan Yang

Electrical and Computer Engineering Faculty Research & Creative Works

The electromagnetic modeling of practical finite periodic structures is a topic of growing interest. Due to the truncation of infinite periodic structures, surface waves will be excited and localized near discontinuous interfaces leading to the edge effect. In this work, surface waves are numerically extracted and their magnitudes and decay rates are analyzed for different materials and geometries. Based on the exponential decay of the surface wave, a novel method is developed by connecting the solution to the large finite array problem with that to a relatively small one to achieve low complexity and memory consumption. The method numerically reconstructs …

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