Engineering Commons^™

A Resource Efficient Localized Recurrent Neural Network Architecture And Learning Algorithm, Daniel Borisovich Budik

Masters Theses

Recurrent neural networks (RNNs) are widely acknowledged as an effective tool that can be employed by a wide range of applications that store and process temporal sequences. The ability of RNNs to capture complex, nonlinear system dynamics has served as a driving motivation for their study. RNNs have the potential to be effectively used in modeling, system identification and adaptive control applications, to name a few, where other techniques fall short. Most of the proposed RNN learning algorithms rely on the calculation of error gradients with respect to the network weights. What distinguishes recurrent neural networks from static, or feedforward …

Using Physical Compilation To Implement A System On Chip Platform, Pradeep M. Chimakurthy

Masters Theses

The goal of this thesis was to setup a complete design flow involving physical synthesis. The design chosen for this purpose was a system-on-chip (SoC) platform developed at the University of Tennessee. It involves a Leon Processor with a minimal cache configuration, an AMBA on-chip bus and an Advanced Encryption Standard module which performs decryption.

As transistor size has entered the deep submicron level, iterations involved in the design cycle have increased due to the domination of interconnect delays over cell delays. Traditionally, interconnect delay has been estimated through the use of wire-load models. However, since there is no physical …

Microprocessor Implementation Of Autoregressive Analysis Of Process Sensor Signals, Swetha Priyanka Pakala

Masters Theses

Automated signal analysis can help for effective system surveillance and also to analyze the dynamic behavior of the system such as impulse response, step response etc. Autoregressive analysis is a parametric technique widely used for system surveillance and diagnosis. The main aim objective of this research work is to develop an embedded system for autoregressive analysis of sensor signals in an online fashion for monitoring system parameters. This thesis presents the algorithm, data representation and performance of the optimized microprocessor implementation of autoregressive analysis.

In this work an autoregressive (AR) model is generated as a solution to a linear system …

A Distributed Solution For Visual Sensor Networks To Detect Targets In Crowds, Cheng Qian

Masters Theses

Visual sensor networks (VSNs), a novel concept about fulfilling vision tasks by a network of collaborative visual sensors, has been attracting more and more attentions these days. This thesis introduces some pioneering research on developing a distributed algorithm for VSNs to detect targets in a cluttered scene. The algorithm is aimed to achieve excellent performances on both detection accuracy and energy efficiency.

Based on a statistical model of the cluttered scene, the development starts with a centralized version where all the nodes send visual data to a central node and the central node invokes an iterative prioritization strategy (IPS) to …

A Fuzzy Logic Controller For Autonomous Wheeled Vehicles, Mohamed Trabia, Linda Z. Shi, Neil Eugene Hodge

Mechanical Engineering Faculty Research

Autonomous vehicles have potential applications in many fields, such as replacing humans in hazardous environments, conducting military missions, and performing routine tasks for industry. Driving ground vehicles is an area where human performance has proven to be reliable. Drivers typically respond quickly to sudden changes in their environment. While other control techniques may be used to control a vehicle, fuzzy logic has certain advantages in this area; one of them is its ability to incorporate human knowledge and experience, via language, into relationships among the given quantities. Fuzzy logic controllers for autonomous vehicles have been successfully applied to address various …

“Design, Development And Characterization Of A Thermal Sensor Brick System For Modular Robotics, Nikhil Arun Naik

Masters Theses

This thesis presents the work on thermal imaging sensor brick (TISB) system for modular robotics. The research demonstrates the design, development and characterization of the TISB system. The TISB system is based on the design philosophy of sensor bricks for modular robotics. In under vehicle surveillance for threat detection, which is a target application of this work we have demonstrated the advantages of the TISB system over purely vision-based systems. We have highlighted the advantages of the TISB system as an illumination invariant threat detection system for detecting hidden threat objects in the undercarriage of a car. We have compared …

Novel Capacitance Extraction Method Using Direct Boundary Integral Equation Method And Hierarchical Approach, L. (Lijun) J. Jiang, B. J. Rubin, J. D. Morsey, H. T. Hu, A. Elfadel

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel hierarchical capacitance extraction method is introduced. It takes advantage of surface integral equations to have far less unknowns than the volumetric method. It uses the "divide and conquer" strategy to hierarchically solve the dense capacitance matrix efficiently. It partitions the problem into small regions (cells) automatically and each region is analyzed separately. An inverse binary-tree browse procedure is employed to combine cell capacitance matrixes from leafy level of the tree to the root. A global capacitance matrix is obtained at the root without computing charge distribution. Benchmarks using the developed code CSurf are provided to …

Numerical Analysis Of Sandwiched Composite-Fss Structures, Qiang Rui, Chen Ji, Huang Jingyu, Maria Koledintseva, Richard E. Dubroff, James L. Drewniak, Yang Fan

Electrical and Computer Engineering Faculty Research & Creative Works

A numerical technique to analyze shielding effectiveness of sandwiched FSS-composite structures is proposed. This technique is based on using a dispersive FDTD method in conjuncture with a novel periodic boundary condition to model sandwiched FSS-composite elements. Results show that by inserting single or multilayered FSS elements into composite materials, better shielding effectiveness can be achieved. © 2006 IEEE.

Integral Equation Solvers For Real World Applications -Some Challenge Problems, W. C. Chew, I. T. Chiang, C. P. Davis, A. Hesford, M. K. Li, Y. Liu, Z. G. Qian, M. Saville, L. Sun, M. S. Tong, J. Xiong, L. (Lijun) J. Jiang, H. Y. Chao, Y. H. Chu

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

The Use Of Fast Integral Equations Solvers For Practical Package And Interconnect Analysis, J. D. Morsey, B. J. Rubin, L. (Lijun) Jiang, L. Shan, L. B. Eisenberg, D. Becker, M. Arseneault

Electrical and Computer Engineering Faculty Research & Creative Works

Fast integral equation methods are now being applied to packaging and other such "low frequency" problems. This paper explores some of the issues surrounding such an application to real, product level packaging and interconnect type structures. Discussed are issues such as low frequency breakdown, mesh aspect ratios, and solver convergence. Finally, integral equation solver examples are presented using the IBM internally developed pre-corrected FFT (PFFT) solver labeled EMSurf[l]. ©2006 IEEE.

Robust Estimation Of Mahalanobis Distance In Hyperspectral Images, Eduardo C. Meidunas

Theses and Dissertations

This dissertation develops new estimation methods that fit Johnson distributions and generalized Pareto distributions to hyperspectral Mahalanobis distances. The Johnson distribution fit is optimized using a new method which monitors the second derivative behavior of exceedance probability to mitigate potential outlier effects. This univariate distribution is then used to derive an elliptically contoured multivariate density model for the pixel data. The generalized Pareto distribution models are optimized by a new two-pass method that estimates the tail-index parameter. This method minimizes the mean squared fitting error by correcting parameter values using data distance information from an initial pass. A unique method …

Design And Implementation Of A Complex-Conjugate Shaper And Baseline Restorer For A Silicon-Based Neutron Detector Front-End, Jonathan Lanier Britton

Masters Theses

This thesis presents the design and implementation of a CMOS shaper with baseline restoration for use in the silicon-based neutron detector front-end to be used at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL). The system consists of a voltage-to-current (V-to-I) converter, a four-pole complex-conjugate semi-Gaussian current-input active filter, and a ground-sensing baseline restorer (BLR) operational transconductance amplifier (OTA). The first prototype chip Patara has been fabricated in the TSMC 0.35-micron process, and experimental results show that proper functionality was achieved. The shaper, which is influenced by a real pole prior to the V-to-I converter, has …

Fpga Logic Design For Analog-To-Digital-Converter Hardware Utilizing High Speed Serial Data Links, Joshua Brandon Jones

Masters Theses

The Computer Assisted Dynamic Data Monitoring and Analysis System (CADDMAS) used by the aeropropulsion test cells at Arnold Engineering Development Center (AEDC) processes a large amount of high bandwidth accelerometer and strain gage data. Data from each sensor must be digitized before being processed by software running on networked computers. This thesis describes some of the original analog-to- digital converter (ADC) hardware used by the CADDMAS as well as some of its limitations. More up-to-date ADC hardware was designed to be used in the CADDMAS to enhance capabilities required by the aeropropulsion test cells. These new capabilities included an increase …

A Generalized Neuron Based Adaptive Power System Stabilizer For Multimachine Environment, D. K. Chaturvedi, O. P. Malik

D. K. Chaturvedi Dr.

Artificial neural networks trained as intelligent controllers can easily accommodate the non-linearities and time dependencies of non-linear, dynamic systems. However, they require large training time and large number of neurons to deal with complex problems. Taking benefit of the characteristics of a generalized neuron (GN), that requires much smaller training data and shorter training time, a generalized neuron based adaptive power system stabilizer (GNAPSS) is proposed. It consists of a GN as an predictor, that predicts the plant dynamics, and a GN as a controller to damp low frequency oscillations. Results show that the proposed GNAPSS can provide a consistently …

Reaction Mechanism Of V(Ⅳ)/V(Ⅴ) Redox Couple At Graphite Felt Composite Electrode Bonded With Conductive Carbon Plastic, Xiao-Gang Li, Ke-Long Huang, Liusu-Qin Liusu-Qin, Ning Tan, Li-Quan Chen

Journal of Electrochemistry

The rate-determining step of V(Ⅳ) /V(Ⅴ) redoxreaction was investigated at graphite felt(GF)composite electrode by various techniques: cyclic voltammetry,polarization curve and impedance spectroscopy.Cyclic voltammetry analysis indicated that V(Ⅳ) /V(Ⅴ) redox reaction at GF electrode is quasi reversible.Acertain chemical reaction step is suspected to follow the electron transfer step of this reaction.The Tafel slopevalue(0.124) obtained from the polarization curve agrees well with theoretical value(0.12),which supposingthe electron transfer step was the rate-determining step.Impedance Spectroscopies at various potentials werestudied and simulated by equivalentcircuits.The impedance value of the electron transfer step modified is greatlyhigher than the others,which shows that the electron transfer step is the …

The Synthesis,Structure And Electrochemical Performances Of Lithium Iron Phosphate, Hui Xie

Journal of Electrochemistry

The lithium iron phosphate cathode materials were synthesized by solid-state reaction combined high-rate ball milling under the temperature ranging from 400 ℃ to 700 ℃.The crystalline structure,morphology of particles,and electrochemical performance of the sample were investigated by X-ray diffraction,scanning electron microscopy and charge-discharge test.The results showed that the sintering temperature had great influences on the crystal structure,morphology and electrochemical performances of LiFePO_(4).The sample synthesized under 600℃ showed the best charge-discharge performances with the first specific discharge capacity of(128.8) mAh/g and the 15~(th) specific discharge capacity of 129.1 mAh/g at 0.1C rate,each charge-discharge cycling efficiency being 99.7%.Also the sample showed good …

Synthesis Of Monolithic Carbon/Nickel Oxide Composite Electrode Material And Cyclic Voltammetry Characteristics, Tian-Ying Guo, Jing-Wei Zhu, Mou-Dao Song, Bang-Hua Zhang

Journal of Electrochemistry

Monolithic carbon/nickel oxide composite materials were synthesized by carbonization of phenol formaldehyde gels that were ion-exchanged with Ni~(2+).Atomic absorption spectroscopy and powder X-ray diffraction technique were used to characterize the chemical composition and physical structure of the materials.The nickel dope amount for this method can reach 5.9 %(by mass).Subsequent cyclic voltammetry experiments indicate that the materials exhibit best capacitive performance at the nickel content of 4.4 %.

Electrochemical Behavior Of Buprofezin On Glass-Carbon Electrode, Qi Wang, Chang-Guo Chen

Journal of Electrochemistry

Electrochemical behavior of Bup has been investigated by means of cyclic voltammetry,linear sweep voltammetry,differential pulse voltammetry and square wave voltammetry.The results indicate that the electrochemical behavior of Bup on the surface of glassy carbon electrode is corresponding to a irreversible two-protons and two-electrons process with absrption.The square wave voltammetry for determination of Bup in actual samples has been established.

Facilitated Effect Of Ag To Oxygen Transportation In Pem Fuel Cell Air Cathodes, Hong-Feng Xu, Jian-Hua Dong, Xiang-Li Hou

Journal of Electrochemistry

Silver(Ag) was deposited in the pores of Nafion membrane by ion exchange and succedent hydrogen reduction;the structures of Nafion-Ag membrane were measured by TEM and XRD,the diffusion coefficients of oxygen in Nafion-Ag was determined by electrochemical limited current method.The results showed that after deposited silver,the pores in the Nafion were enlarged by silver grains;the oxygen diffusion coefficient was increased about four times.By introducing silver in the thin Nafion film around the cathode catalyst,the performance of PEM fuel cell have a evident increasing in high current density, which shows the facilitated effects of silver to oxygen transportation in PEM fuel cell.

Structure And Electrochemical Characteristics Of Lifepo_4 Prepared By The Polyacrylates-Pyrolysis-Reduction Method For Li-Ion Batteries, Li-Hong Yu, Yu-Liang Cao, Xiao-Fei Zhang, Han-Xi Yang, Xin-Ping Ai

Journal of Electrochemistry

The cathode material of olivine LiFePO_(4) was prepared by a novel method of polyacrylate-pyrolysis-reduction.XRD demonstrates that the material have the olivine structure.SEM photo shows an average particle-size of about 100 nm with a well distribution.Electrochemical test of cycling at a constant current reveals the discharge capacity of 138 mAh/g and a good cycling stability.It is a novel practicable technology to prepare LiFePO_(4) by using polyacrylate-pyrolysis-reduction method.

Novel Electrochemical Method For Synthesis Of Nanostructured Materials Of Noble Metals Based On Poly(N-Vinylpyrrolidone) (Pvp), Wei Pan

Journal of Electrochemistry

Gold nanocrystals with controllable size were synthesized through a simple electroreduction method using poly(N-vinylpyrrolidone)(PVP) of different polymerization degree as both stabilizer and shape-controller for gold nanoclusters.Individual gold nanoparticles spontaneously assembled into the wire-and ring-shaped nanoparticle aggregates depending on the PVP's dynamic stretching and curling,and precursor nanoparticles grew into flat,single-crystalline nanoprisms with thickness of dozens of nanometers based on the oriented aggregation between particles.Besides,core-shell Au/Ag nanoparticles were conveniently synthesized through two-step electroreduction of noble metal ions in the presence of PVPK30.The electrochemical synthetic method based on PVP provides a new path for preparation of noble metal nanostructured materials with different shape …

Synergistic Functions Of Trimethl Phosphate And Vinylene Carbonate As Additives For The Li-Ion Batteries, Zhi-Yuan Tang, Yan-Bing He, Quan-Sheng Song, Yu-Hong Chen, Yuan-Gang Liu, Qiang Liu

Journal of Electrochemistry

The cooperative effects of trimethl phosphate and vinylene carbonate as additives for Li-ion batteries are investigated by using the cyclic voltammetry,electrochemical impedance spectroscopy and scanning electronic micro-photographs.The results show that the combination application of TMP and VC as additives for Li-ion batteries not only enhances safety of the batteries,but also improves their cycling performance.The reason may be ascribed to firstly VC being reduced and the reduction product polymerized to form excellent solid electrolyte interface(SEI) layer on the surface of graphite electrode during the first charge and discharge process,which prevents effectively the decomposition of TMP on the surface of the graphite …

Electrochemical Properties Of The Modified Carbon Nanotubes, Chun-An Ma

Journal of Electrochemistry

Powder micro-electrodes were prepared from raw carbon nanotubes and carbon nanotubes modified by carboxyl.The electro-reduction properties of both the raw and open-ended carbon nanotubes in p-Nitrophenol solution were investigated.The FTIR spectrum result indicated that the functional groups are successfully fixed on the surface of the carbon nanotubes after nitric acid treatment.The cyclic voltammetry results show that the electrochemical activity of carboxyl-modified carbon nanotubes was improved.The mechanism of electro-(reduction) for the carbon nanotubes after acid treatment was discussed.

Study Of The Electrooxidation Of Glycerol On Oxide And Pd/C Composite Catalysts, Zhi-Yuan Yan, Chang-Wei Xu, Pei-Kang Shen

Journal of Electrochemistry

Oxide and Pd on carbon composite catalysts have been prepared by intermittent microwave heating(IMH) method.The performance of the catalysts for glycerol oxidation in alkaline solution is studied by electrochemical techniques.It is shown that the Pd/C catalyst is active for glycerol electrooxidation.However,the oxide-Pd/C catalysts are even better in terms of the onset potential that is more negative and peak current density.The ratio of oxide to Pd is optimized according to the electrochemical measurement.The results reveal that the addition of oxide into the Pd/C induces the synergistic effect for glycerol electrooxidation.

Performance And Characterization Of A Large Format Solid State Imager, Jacob A. Mendez

Electrical and Computer Engineering ETDs

The purpose of this thesis is to validate the specifications of the CCD 486 as specified by Fairchild Imaging, the manufacturer of the CCD and Spectral Instruments, the manufacturer of the camera control electronics and supporting hardware. Specifications have been provided by both companies and are shown in Appendix A. This study is necessary because of the nature of the experiments to be analyzed using the CCD 486. In addition, the thesis will propose new testing methods for electronically shuttered CCD imagers that are not well understood.

Oct-Based Elastography For Large And Small Deformations, Donald D. Duncan, Sean J. Kirkpatrick, Ruikang K. Wang

Electrical and Computer Engineering Faculty Publications and Presentations

We present two approaches to speckle tracking for optical coherence tomography (OCT)-based elastography, one appropriate for small speckle motions and the other for large, rapid speckle motions. Both approaches have certain advantages over traditional cross-correlation based motion algorithms. We apply our algorithms to quantifying the strain response of a mechanically inhomogeneous, bi-layered polyvinyl alcohol tissue phantom that is subjected to either small or large dynamic compressive forces while being imaged with a spectral domain OCT system. In both the small and large deformation scenarios, the algorithms performed well, clearly identifying the two mechanically disparate regions of the phantom. The stiffness …

Krf Excimer Laser-Assisted Combustion-Flame Deposition Of Diamond Films, Y. X. Han, Hao Ling, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Cobalt (Co) composition has detrimental effects on the deposition of diamond films on cemented tungsten carbide (WC-Co) substrates. It decreases adhesion of the deposited films to the substrates and causes a transformation of sp³-bonded diamond to sp²-bonded graphite. In this study, a KrF excimer laser with a wavelength of 248 nm, a pulse width of 23 ns, and a pulse energy range of 84–450 mJ was used in the combustion-flame method to improve the quality of the deposited diamond films. Scanning electron microscopy, energy dispersive x-ray analysis, and Raman spectroscopy of the deposited films showed that …

Predicting On-Orbit Static Single Event Upset Rates In Xilinx Virtex Fpgas, Joshua Engel, Keith S. Morgan, Michael J. Wirthlin, Paul S. Graham

Faculty Publications

Sponsorship: Department of Energy, Los Alamos National Laboratory. This document describes the methodology used to predict single-event upset rates for Xilinx Virtex FPGAs based on the CREME96 orbit modeling tool. Using this methodology, SEU upset rates are obtained for several Xilinx Virtex FPGAs including Virtex, Virtex-II, and Virtex-4. Further, SEU upset rates are obtained for a variety of orbits for each of these FPGAs.

Mimo Communication Capacity: Antenna Coupling And Precoding For Incoherent Detection, Nicolas W. Bikhazi

Theses and Dissertations

While the capacity of multiple-input multiple-output (MIMO) systems has been explored in considerable detail, virtually all literature on this topic ignores electromagnetic considerations. This dissertation explores electromagnetic effects on the capacity performance of these multi-antenna architectures. Specifically, it examines the impact of superdirectivity for compact antenna arrays, the effect of antenna mutual coupling, and MIMO performance of multi-mode optical fiber with non-linear detection. Superdirectivity can lead to abnormally large capacity bounds in a MIMO communication system, especially when the antennas are placed close together. Because superdirective behavior is difficult to achieve in practice, this work formulates an approach for limiting …

Bright Contrast Imaging Of Carbon Nanofiber-Substrate Interface, Makoto Suzuki, Hirohiko Kitsuki, Quoc Ngo, Cary Y. Yang

Electrical and Computer Engineering

We present the contrast mechanisms of scanning electron microscopy (SEM) for visualizing the interface between carbon nanofibers (CNFs) and the underlying substrate. SEM imaging with electron beam energies higher than a certain threshold provides different image contrasts depending on whether CNFs are in contact with the substrate or suspended above the substrate. CNFs with diameters ranging from 25to250nm are examined with various electron beam energies. It is found that the threshold energy corresponds to the energy required to penetrate the CNF and its dependence on CNF diameter can be understood using the theory of electron range. This knowledge will be …