Electrical and Computer Engineering Commons^™

Fast Block Matching Using Minkowski's Inequality, Jim Zong-Chang Lai, Yi-Ching Liaw, Shih-An Fong

Journal of Marine Science and Technology

In this paper, we present a fast block matching algorithm by making use of the Minkowski’s inequality. Combined with other fast block matching algorithms, our method can further reduce the computational complexity significantly with little PSNR degradation. Compared to the full search block matching algorithm, our approach can reduce the computing time by a factor of 6.4 to 21.5. Compared to MSEQ, which is a wellknown block matching algorithm preserving global optimality, our method can further reduce the corresponding computing time in average by 32.4%. The combination of our algorithm and the predictive search area approach for block motion estimation …

Estimation Model Of Transformer Iron Loss Using Neural Network, Tai-Ken Lu, Chien-Ta Yeh, Min-Doon Dirn

Journal of Marine Science and Technology

When we want to calculate the transformer iron loss in operation, in addition to considering the nonlinear hysteretic phenomenon of transformer itself and the natural unbalanced characteristic, the actual situation that the transformer is operated under three phase unbalance state should also be considered. This results in very non-regular change of the transformer iron loss, and the accuracy of the polynomial model that is commonly used to estimate the iron loss of the transformer in the past is thus reduced. Since neural network has parallel processing capability, which can process highly nonlinear function problem, hence, in this study, we try …

Effect Of Commutation Failures On Torsional Vibrations Of A Turbine Generator Nearby An Hvdc Link, Chi-Hshiung Lin

Journal of Marine Science and Technology

For an HVDC system, it is studied the torsional vibrations induced on the inverter side turbine generators due to a rectifier side ac faults. It is found there may be up to several times difference in the torsional torques induced at the turbine shafts and blades for the same fault, depending on the inverter commutation behavior. Further, if a single-phase-to-ground fault takes place with the commutation failure, it might cause a more serious impact on the turbine generator unit than a threephase-to-ground fault without commutation failure.

Selection Criteria To Statistical Models, D. K. Chaturvedi

D. K. Chaturvedi Dr.

No abstract provided.

A Hardware/Software Co-Design Architecture For Thermal, Power, And Reliability Management In Chip Multiprocessors, Omer Khan

Open Access Dissertations

Today’s designs are being shaped by the challenges of nano-CMOS technologies: increased power density, rising junction temperatures, and rising rate of errors and device failures that constrain average rate of power dissipation, and design technologies that limit peak power delivery. This thesis focuses on how to leverage the hardware and software abstraction layers of today’s systems. Several of the low level hardware details such as power, hotspots, and faults are tightly correlated to interactions within the system including application and hardware behavior. The conventional approach to tackling such problems come with additional costs and design complexity, and they are limited …

Protocol And System Design For A Service-Centric Network Architecture, Xin Huang

Open Access Dissertations

Next-generation Internet will be governed by the need for flexibility. Heterogeneous end-systems, novel applications, and security and manageability challenges require networks to provide a broad range of services that go beyond store-and-forward. Following this trend, a service-centric network architecture is proposed for the next-generation Internet. It utilizes router-based programmability to provide packet processing services inside the network and decompose communications into these service blocks. By providing different compositions of services along the data path, such network can customize its connections to satisfy various communication requirements. This design extends the flexibility of the Internet to meet its next-generation challenges. This work …

Large Direct Repeats Flank Genomic Rearrangements Between A New Clinical Isolate Of Francisella Tularensis Subsp. Tularensis A1 And Schu S4, Ufuk Nalbantoglu, Khalid Sayood, Michael P. Dempsey, Peter C. Iwen, Stephen C. Francesconi, Ravi D. Barabote, Gary Xie, Thomas S. Brettin, Steven H. Hinrichs, Paul D. Fey

Department of Electrical and Computer Engineering: Faculty Publications

Francisella tularensis subspecies tularensis consists of two separate populations A1 and A2. This report describes the complete genome sequence of NE061598, an F. tularensis subspecies tularensis A1 isolated in 1998 from a human with clinical disease in Nebraska, United States of America. The genome sequence was compared to Schu S4, an F. tularensis subspecies tularensis A1a strain originally isolated in Ohio in 1941. It was determined that there were 25 nucleotide polymorphisms (22 SNPs and 3 indels) between Schu S4 and NE061598; two of these polymorphisms were in potential virulence loci. Pulsed-field gel electrophoresis analysis demonstrated that NE061598 was an …

The Value Of Concentrating Solar Power And Thermal Energy Storage, Ramteen Sioshansi, Paul Denholm

Publications (E)

This paper examines the value of concentrating solar power (CSP) and thermal energy storage (TES) in four regions in the southwestern United States. Our analysis shows that TES can increase the value of CSP by allowing more thermal energy from a CSP plant’s solar field to be used, by allowing a CSP plant to accommodate a larger solar field, and by allowing CSP generation to be shifted to hours with higher energy prices. We analyze the sensitivity of CSP value to a number of factors, including the optimization period, price and solar forecasting, ancillary service sales, capacity value and dry …

Doe Request For Information (Rfi) De-Foa-0000153 Pv Manufacturing Initiative: Summary Report, National Renewable Energy Laboratory

Publications (E)

Clean Cities hosts a collection of tools on the exploring concepts for a “PV Manufacturing Initiative” to facilitate the development of a strong photovoltaic (PV) manufacturing industry in the United States. As an integral part this effort, and to inform the creation of a new funding opportunity in this area, DOE sought feedback from the PV industry.

This document summarizes the results of the PV Manufacturing Request for Information (RFI), DE-FOA-0000153. (See Attachment 1.) The RFI was posted on http://www.grants.gov on 4 September 2009 and the NREL Web site on 9 September 2009. Respondents were asked to submit RFI inputs …

H-Matrix-Based Fast Direct Finite Element Solver For Large-Scale Electromagnetic Analysis, Haixin Liu, Dan Jiao

Department of Electrical and Computer Engineering Technical Reports

In this work, we prove that the sparse matrix resulting from a finite-element-based analysis of electrodynamic problems can be represented by an H-matrix without any approximation, and the inverse of this sparse matrix has a data-sparse H-matrix approximation with error well controlled. Based on this proof, we develop an H-matrix-based direct finite-element solver of O(kNlogN) memory complexity and O(k2Nlog2N) time complexity for solving electromagnetic problems, where k is a small variable that is adaptively determined based on accuracy requirements, and N is the number of unknowns. Both inversebased and LU-based direct solutions are developed. The LU-based solution is further accelerated …

A Theoretically Rigorous Full-Wave Finite-Element-Based Solution Of Maxwell's Equations From Dc To High Frequencies, Jianfang Zhu, Dan Jiao

Department of Electrical and Computer Engineering Technical Reports

It has been observed that finite element based solutions of full-wave Maxwell's equations break down at low frequencies. In this paper, we present a theoretically rigorous method to fundamentally eliminate the low-frequency breakdown problem. The key idea of this method is that the original frequency-dependent deterministic problem can be rigorously solved from a generalized eigenvalue problem that is frequency independent. In addition, we found that the zero eigenvalues of the generalized eigenvalue problem cannot be obtained as zeros because of finite machine precision. We hence correct the inexact zero eigenvalues to be exact zeros. The validity and accuracy of the …

Acoustic Censusing Using Automatic Vocalization Classification And Identity Recognition, Kuntoro Adi, Michael T. Johnson, Tomasz S. Osiejuk

Electrical and Computer Engineering Faculty Research and Publications

This paper presents an advanced method to acoustically assess animal abundance. The framework combines supervised classification (song-type and individual identity recognition), unsupervised classification (individual identity clustering), and the mark-recapture model of abundance estimation. The underlying algorithm is based on clustering using hidden Markovmodels (HMMs) and Gaussian mixture models (GMMs) similar to methods used in the speech recognition community for tasks such as speaker identification and clustering. Initial experiments using a Norwegian ortolan bunting (Emberiza hortulana) data set show the feasibility and effectiveness of the approach. Individually distinct acoustic features have been observed in a wide range of animal …

A Majorization Algorithm For Constrained Correlation Matrix Approximation, Daniel J. Simon, Jeff Abell

Electrical and Computer Engineering Faculty Publications

We desire to find a correlation matrix of a given rank that is as close as possible to an input matrix R, subject to the constraint that specified elements in must be zero. Our optimality criterion is the weighted Frobenius norm of the approximation error, and we use a constrained majorization algorithm to solve the problem. Although many correlation matrix approximation approaches have been proposed, this specific problem, with the rank specification and the constraints, has not been studied until now. We discuss solution feasibility, convergence, and computational effort. We also present several examples.

Effects Of Hydrogen Pretreatment On Physical-Vapor-Deposited Nickel Catalyst For Multi-Walled Carbon Nanotube Growth, Benjamin L. Crossley, Mauricio Kossler, Ronald A. Coutu Jr., Lavern A. Starman, Peter J. Collins

Electrical and Computer Engineering Faculty Research and Publications

Physical vapor deposited nickel catalyst layers of 10, 50, 100, 200, 350, and 500 angstroms were granulated using hydrogen plasma for varying times to determine an effective carbon nanotube (CNT) growth process using microwave plasma enhanced CVD (MPECVD). Nickel was deposited via sputtering or evaporation. The catalyst granule size, density, and resulting CNTs were analyzed. Sputtered nickel of 50 angstroms with 5 minutes of hydrogen plasma pretreatment resulted in the most effective CNT growth.

Recurrent Neural Networks Based Impedance Measurement Technique For Power Electronic Systems, Peng Xiao, Ganesh K. Venayagamoorthy, Keith Corzine, Jing Huang

Electrical and Computer Engineering Faculty Research & Creative Works

When designing and building power systems that contain power electronic switching sources and loads, system integrators must consider the frequency-dependent impedance characteristics at an interface to ensure system stability. Stability criteria have been developed in terms of source and load impedance, and it is often necessary to measure system impedance through experiments. Traditional injection-based impedance measurement techniques require multiple online testing that lead to many disadvantages, including prolonged test time, operating point variations, and impedance values at limited frequency points. The impedance identification method proposed in this paper greatly reduces online testing time by modeling the system with recurrent neural …

Constrained Kalman Filtering Via Density Function Truncation For Turbofan Engine Health Estimation, Daniel J. Simon, Donald L. Simon

Electrical and Computer Engineering Faculty Publications

Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. This article develops an analytic method of incorporating state variable inequality constraints in the Kalman filter. The resultant filter truncates the probability density function (PDF) of the Kalman filter estimate at the known constraints and then computes the constrained …

Causal Rlgc( Ƒ ) Models For Transmission Lines From Measured S-Parameters, Jianmin Zhang, James L. Drewniak, David Pommerenke, Marina Koledintseva, Richard E. Dubroff, Wheling Cheng, Zhiping Yang, Qinghua B. Chen, Antonio Orlandi

Electrical and Computer Engineering Faculty Research & Creative Works

Frequency-dependent causal RLGC(f) models are proposed for single-ended and coupled transmission lines. Dielectric loss, dielectric dispersion, and skin-effect loss are taken into account. The dielectric substrate is described by the two-term Debye frequency dependence, and the transmission line conductors are of finite conductivity. In this paper, three frequency-dependent RLGC models are studied. One is the known frequency-dependent analytical RLGC model ( RLGC-I), the second is the RLGC(f) model (RLGC-II) proposed in this paper, and the third (RLGC-III) is same as the RLGC -II, but with causality enforced by the Hilbert transform in frequency domain. The causalities of the three RLGC …

Reducing Common-Mode Voltage In Three-Phase Sine-Triangle Pwm With Interleaved Carriers, Jonathan W. Kimball, Maciej Jan Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

Interleaving PWM waveforms is a proven method to reduce ripple in dc-dc converters. The present work explores interleaving for three-phase motor drives. Fourier analysis shows that interleaving the carriers in conventional uniform PWM significantly reduces the common-mode voltage. New DSP hardware supports interleaving directly with changes to just two registers at setup time, so no additional computation time is needed during operation. The common-mode voltage reduction ranges from 36% at full modulation to 67% when idling with zero modulation. Third harmonic injection slightly reduces the advantage (to 26% at full modulation). However, the maximum RMS common-mode voltage is still less …

A Novel Approach To Interarea Oscillation Damping By Unified Power Flow Controllers Utilizing Ultracapacitors, Mahyar Zarghami, Mariesa Crow, Jagannathan Sarangapani, Yilu Liu, Stan Atcitty

Electrical and Computer Engineering Faculty Research & Creative Works

This paper discusses a novel approach for damping interarea oscillations in a bulk power network using multiple unified power flow controllers (UPFCs) utilizing ultracapacitors, also known more generally as electrochemical capacitors (ECs). In this paper, a new control is introduced to mitigate interarea oscillations by directly controlling the UPFCs' sending and receiving bus voltages that better utilizes the stored energy in the ECs. The results of this controller are compared with and without ECs. The proposed control provides better interarea oscillation mitigation when applied to multiple UPFCs in the 118-bus IEEE test system.

Statistical Approach For Yield Optimization For Minimum Energy Operation In Subthreshold Circuits Considering Variability Issues, Md. Waliullah Khan Nomani, Mohab Anis, Goutam Koley

Faculty Publications

The supply voltage (V-dd) and threshold voltage (V-th) are two significant design variables that directly impact the performance and power consumption of circuits. The scaling of these voltages has become a popular option to satisfy performance and low power requirements. Subthreshold operation is a compelling approach for energy-constrained applications where processor speed is less important. However, subthreshold designs show dramatically increased sensitivity to process variations due to the exponential relationship of subthreshold drive current with V-th variation and drastically growing leakage power. If there is uncertainty in the value of the threshold or supply voltage, the power advantages of this …