Digital Commons Network^™

Space Charge Structure Of A Glow Discharge In The Presence Of A Longitudinal Inhomogeneity, Frank A. Tersigni

Theses and Dissertations

A survey of space charge structures arising due to inhomogeneities in glow discharges was conducted. Space charge structures associated with tube geometries, the cathode sheath, striations, and shockwaves were examined. Space charge effects on the Electron Energy Distribution Function (EEDF) were explored for a geometric inhomogeneity using an approximate nonlocal solution to the one dimensional Boltzmann equation after Godyak. The approximate solution partially captured qualitative aspects of space charge effects on the EEDF. Simplification of collisional effects and adaptation of an approximate electric field restricted quantitative comparisons with experimental data. It is recommended that any future analysis of space charge …

Target Pose Estimation From Radar Data Using Adaptive Networks, Andrew W. Learn

Theses and Dissertations

his research investigates and extends recent work by J.C. Principe at the University of Florida in target pose estimation using adaptive networks. First, Principe's technique is successfully extended to estimate both azimuth and elevation using SAR images. A network trained and tested using MSTAR data yields mean errors of less than six degrees in azimuth and five degrees in elevation. Second, the technique is applied to high-range resolution radar (HRR) signatures. Ground target (azimuth only) testing yields mean errors of less than 11 degrees for most classes. Air target testing for networks trained and tested on the same aircraft class …

Analysis Of The Applicability Of Video Segmentation To Unmanned Aerial Vehicle Surveillance Video, Bradley L. Pyburn

Theses and Dissertations

The focus of this research is to determine if applying edge detection segmentation (proposed by Ramin Zabih, Justin Miller, and Kevin Mai) to Unmanned Aerial Vehicle (UAV) video footage can provide meaningful segments for database storage and retrieval. The edge detection segmentation algorithm is applied to fifty-four UAV video sequences containing visual effects such as abrupt camera changes, camera zooms, motion (rapid and gradual), and cloud cover while varying the frame rate from 5 fps to 30 fps. An analysis of the results is performed to compare actual versus expected outcomes, similar sequences, and scenes with motion, along with explaining …

Modulation Of Electrostatic Microelectromechanical Mirrors Using A Cmos Controller, Paul C. Rounsavall

Theses and Dissertations

Microelectromechanical Systems (MEMS) is a rapidly growing technology that lends itself particularly well to optical applications. An example of an optical MEMS device is the piston-action mirror that modulates the phase of reflected light. The phase of reflected light can be varied using thermal or electrostatic actuation to control the position of the mirror. In previous research, a modulation method to control thermally actuated mirrors was developed. This thesis presents the development, implementation, fabrication, and testing of a complimentary metal oxide semiconductor (CMOS) controller capable of directly interfacing between a digital system, such as a computer, and an electrostatically actuated …

Studies Of Electrochemical Characteristics Of Pasted Nickel Hydroxide Electrode With Surface Deposited Cobalt, Xian-You Wang, Yun-Shi Zhang, Jie Yan, Zheng Zhu, Hua-Tang Yuan, De-Ying Song

Journal of Electrochemistry

The surface of the spherical nickel hydroxide particles used as an active material in pasted nickel electrodes is surface-deposited with cobalt. This paper investigated the effects of the amount of cobalt deposit on the characteristics of nickel hydroxide electrode. The performances of the electrode, such as discharge capacity, utilization of active material and reversibility of Ni(OH)₂/NiOOH redox reaction, were studied by comparing the charging/discharging curves and cyclic voltammograms. The mechanism of action of cobalt deposits has been described in terms of the electrochemical impedance spectroscopy of nickel hydroxide electrode.

Oxidation Mechanism Of Hypophosphite, Dong-Bai Sun, Ying Jin, Hong-Ying Yu, De-Jun Yang

Journal of Electrochemistry

There exist two oxidation current peaks on the anodic polarization curve between -0.7 V and 0 V (SCE) in Na-hypophosphite solution. Peak Ⅰ (-0.55 V, SCE) , which represents the oxidation process from H₂PO₂^- to H₂PO₃^-, has been studied previously. Peak Ⅱ, which is located at the potential about -0.4 V (SCE), is investigated emphatically in this paper. The results show that, peak Ⅰ and Ⅱ are corresponding to two successive steps in oxidation process of H₂PO₂^-, i.e. peak Ⅱ corresponds to the oxidation process of …

A New Cell Structure For Proton Exchange Membrane Fuel Cell, Ming Han, Hong-Feng Xu, Bao-Lian Yi

Journal of Electrochemistry

Separating the functions of current collection and gas flow distribution and then to design two separate elements to achieve the desired performance characteristics, a nonconventional cell structure for proton exchange membrane fuel cells bave been developed. The current collector is achieved using a thin stain steel sheet, the gas flow distribution is achieved using a carbon paper that has the desired chemical durabiliy when in contact with the proton exchange membrane. Combining these two separate elements into a single divice yields a bifunctional device that performs as a bipolar separator plate. The advantages of this alternative appproach to making biplar …

Structural And Electrochemical Studies On Todorokite/Vernadite As Cathodes For Rechargeable Lithium Ion Batteries, Wei Chu, De-Yao Liu, Jin-Kua You, Yong Yang, Zu-Geng Lin

Journal of Electrochemistry

XRD, TEM, ICP, low scan-rate CV and charge/discharge tests were carried out for the studies on the structural and electrochemical behavior of a prepared 3 V manganese oxide cathode for rechargeable lithium ion batteries.XRD analysis revealed that the cathode sample is mainly composed of tunneled Todorokite and layered Vernadite. TEM investigation confirmed that the morphology of the sample is a laminated construction with approximate 10nm layer space. The reversibility of Li⁺ removal/intercalation and structural stability of this sample framework to lithium insertion are good in CV and charge/discharge tests. The discharge capacities were found to be about 129mAh/g obtained …

Kinetic Study Of Electrooxidation Of Benzene, Xin-Sheng Zhang, Ping Ding, Ying-Chun Dai, Wei-Kang Yuan

Journal of Electrochemistry

A reaction kinetic study for electrochemical oxidation of benzene was performed on a PbO₂ rotating disk electrode in 1 mol/L H₂SO₄ aqueous solution. The reaction orders, the activation energies and transfer coefficient were measured, and the kinetic expression was obtained.

Synthesis And Application Of Polymeric Corrosion Inhibitor For Reinforced Concrete, Wei-Wei Lin, Sheng-Xian Wang, Jian-Qing Zhang, Jun Yuan, Zhen-Guo Ji

Journal of Electrochemistry

A new polymer E-T was synthesized and used as a corrosion inhibitor for reinforced concrete. The inhibitive behavior and mechanism were studied with linear polarization, Tafel polarization, EIS and XPS method in simulated pore solution system with concrete samples. The result showed that the polymer was a mixing type inhibitor. A 1% dosage was sufficient to imhibit the corrosion of steel in simulated pore solution system. The salt endurance was enhanced from 0.02 mol/L to 0.10 mol/L. The result also showed the good synergetic effect of NaNO₂, especially in low NaNO₂ concentration. The EIS showed that E-T …

Long-Term Memory Motion-Compensated Prediction, Thomas Wiegand, Xiaozheng Zhang, Bernd Girod

Electrical Engineering

Long-term memory motion-compensated prediction extends the spatial displacement vector utilized in block-based hybrid video coding by a variable time delay permitting the use of more frames than the previously decoded one for motion compensated prediction. The long-term memory covers several seconds of decoded frames at the encoder and decoder. The use of multiple frames for motion compensation in most cases provides significantly improved prediction gain. The variable time delay has to be transmitted as side information requiring an additional bit rate which may be prohibitive when the size of the long-term memory becomes too large. Therefore, we control the bit …

An Interactive System For The Estimation Of Emissivity Of A Wafer In A Rapid Thermal Processing Chamber, Maurizio Fulco

Theses

Rapid thermal processing (RTP) is a method of thermally processing wafers for the manufacture of integrated circuits. During the thermal processing of wafers, it is essential that the wafer temperature follow a pre-specified temperature trajectory and that the temperature across the wafer be uniform especially at high temperatures. To ensure that the above objectives of RTP temperature control be met at any time during the process, the estimation of some parameters of the process is of fundamental importance in the design of the control system.

This thesis demonstrates the implementation of an interactive software system in which the emissivity of …

Fundamentals Of Linear State Space Systems, John Bay

Electrical and Computer Engineering Faculty Scholarship

This book addresses two primary deficiencies in the linear systems textbook market: a lack of development of state space methods from the basic principles and a lack of pedagogical focus. The book uses the geometric intuition provided by vector space analysis to develop in a very sequential manner all the essential topics in linear state system theory that a senior or beginning graduate student should know. It does this in an ordered, readable manner, with examples drawn from several areas of engineering. Because it derives state space methods from linear algebra and vector spaces and ties all the topics together …

Design Considerations And Thermodynamic Feasibility Study Of A Meso-Scale Refrigerator, Nabil Shovon Ashraf

Retrospective Theses and Dissertations

Recent advances in micro-fabrication technology have ushered a new era in miniaturization of chemical, environmental and energy systems. This foreseeable trend towards miniaturization in chemical, environmental and mechanical systems is expected to revolutionize the ways the human life is being perceived today. The high volume and mass reproducibility is seen as the striking aspect of micro-fabrication based miniature systems, offering economies far exceeding than the economies of scale obtained in large plants. The focus of this thesis work is directed at the thermodynamic feasibility and preliminary prototype design for a meso-scale refrigerator. Miniaturization to sub-centimeter domain will enable configuring these …

Direct Current Glow Discharges In Atmospheric Air, Robert H. Stark, Karl H. Schoenbach

Bioelectrics Publications

Direct current glow discharges have been operated in atmospheric air by using 100 μm microhollow cathode discharges as plasma cathodes. The glow discharges were operated at currents of up to 22 mA, corresponding to current densities of 3.8 A/cm² and at average electric fields of 1.2 kV/cm. Electron densities in the glow are in the range from 10¹² to 10¹³  cm⁻³. Varying the current of the microhollow cathode discharge allows us to control the current in the atmospheric pressure glow discharge. Large volume atmospheric pressure air plasmas can be generated by operating microhollow cathode discharges …

Multiple Stochastic Learning Automata For Vehicle Path Control In An Automated Highway System, Cem Unsal, Pushkin Kachroo, John S. Bay

Electrical & Computer Engineering Faculty Research

This paper suggests an intelligent controller for an automated vehicle planning its own trajectory based on sensor and communication data. The intelligent controller is designed using the learning stochastic automata theory. Using the data received from on-board sensors, two automata (one for lateral actions, one for longitudinal actions) can learn the best possible action to avoid collisions. The system has the advantage of being able to work in unmodeled stochastic environments, unlike adaptive control methods or expert systems. Simulations for simultaneous lateral and longitudinal control of a vehicle provide encouraging results

On The Global Stabilization Of Nonlinear Systems Via Switching Manifolds, Stephen P. Banks, Meti̇n U. Salamci, M. Kemal Özgören

Turkish Journal of Electrical Engineering and Computer Sciences

The global stabilization of nonlinear systems is investigated by using switching surfaces. The nonlinear system is forced to a lower order switching manifold, which is designed to be stable by construction. Thus, the stability of the reduced-order system is guaranteed and parameter selection for the switching surface is avoided. The method is extended to a class of uncertain nonlinear systems and exemplified with some fictitious dynamic models.

A Simple Formula Obtained Using Tabu Search Algorithm For The Radiation Efficiency Of A Resonant Rectangular Microstrip Antenna, Dervi̇ş Karaboğa, Keri̇m Güney

Turkish Journal of Electrical Engineering and Computer Sciences

A new simple formula for the radiation efficiency of a resonant rectangular microstrip patch antenna is presented. The formula is obtained by using a tabu search algorithm, which is a quite new optimization technique based on the principles of intelligent problem solving. The formula is valid for substrates with relative permittivities between 1 and 12.8 and for the complete range of thicknesses normally used. The results obtained by using this new simple formula are in conformity with those reported elsewhere. The formula can also be used in the calculation of the radiation efficiency of dipoles.

Effects Of Parasitic Elements On Oscillation Frequency Of Ota-C Sinusoidal Oscillators, Ari̇f Nacaroğlu, Ergun Erçelebi̇

Turkish Journal of Electrical Engineering and Computer Sciences

An oscillator circuit which incorporates Operational Transconductance Amplifiers is presented. The circuit is designed using three OTAs and two grounded capacitors. The frequency of oscillation is tunable over a wide frequency range. The effects of the parasitic elements on the oscillation frequency and the oscillation condition are studied. The theoretical results are compared with the experimental results for a practical oscillator circuit.

Implementation And Performance Study Of Image Data Hiding/Watermarking Schemes, Arkadiusz Edward Komenda

Theses

Two data hiding / watermarking techniques for grayscale and color images are presented. One of them is DCT based, another uses DFT to embed data. Both methods were implemented in software utilizing C/C++. The complete listings of these programs are included. A comprehensive reliability analysis was performed on both schemes, subjecting watermarked images to JPEG, SPIRT and MPEG-2 compressions. In addition, the pictures were examined by exposing them to common signal processing operations such as image resizing, rotation, histogram equalization and stretching, random, uniform and Gaussian noise addition, brightness and contrast variations, gamma correction, image sharpening and softening, edge enhancement, …

Differentiating Type Of Muscle Movement Via Ar Modeling And Neural Network Classification, Beki̇r Karlik

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this study is to classify electromyogram (EMG) signals for controlling multifunction proshetic devices. An artificial neural network (ANN) implementation was used for this purpose. Autoregressive (AR) parameters of $a_1, a_2, a_3, a_4$ and their signal power obtained from different arm muscle motions were applied to the input of ANN, which is a multilayer perceptron. At the output layer, for 5000 iterations, six movements were distinguished at a high accuracy of 97.6%.

Dynamic Modeling Of Pwm And Single-Switch Single-Stage Power Factor Correction Converters, Guangyong Zhu

Retrospective Theses and Dissertations

The concept of averaging has been used extensively in the modeling of power electronic circuits to overcome their inherent time-variant nature. Among various methods, the PWM switch modeling approach is most widely accepted in the study of closed-loop stability and transient response because of its accuracy and simplicity. However, a non-ideal PWM switch model considering conduction losses is not available except for converters operating in continuous conduction mode (CCM) and under small ripple conditions. Modeling of conductor losses under large ripple conditions has not been reported in the open literature, especially when the converter operates in discontinuous conduction mode (DCM). …

Application Of The Fdtd Method For The Analysis Of Finite-Sized Phased Array Microstrip Antennas, Javier Gomez Tagle Rangel

Retrospective Theses and Dissertations

The Finite-Difference Time-Domain (FDTD) method has gained tremendous popularity in the past decade as a tool for solving Maxwell's equations. Phased Array Antennas find several applications including mobile communications ( cellular, personal communication systems and networks), satellite communications, global positioning system (GPS), aeronautical and radar systems. This dissertation describes the application of the FDTD method for calculating broadband characteristics of finite-sized phased array antennas consisting of microstrip elements fed with coaxial probes.

The characterization of such antennas is dependent upon the development of simulation tools that can accurately model general topologies including wires, dielectrics, conductors lumped elements and metallic strips. …

Neurocontrol Of Turbogenerators With Adaptive Critic Designs, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design of a neuro-controller for a turbogenerator using a novel technique based on adaptive critic designs (ACD). This adaptive critic design based neuro-controller augments/replaces the traditional automatic voltage regulator (AVR) and the turbine governor of the generator. Simulation results are presented to show that neural network controllers with the ACD have the potential to control turbogenerators when system conditions and configuration changes.

Head Movement And Vision In Underwater-Feeding Birds Of Stream, Lake, And Seashore, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Studies head movement and vision in underwater-feeding birds. Review of relevant literature on the physiological and behavioral aspects of vision; Role of vertical head movement as an aid in the acquisition of visual information.

Mössbauer Effect Determination Of Relative Recoilless Fractions For Iron Oxides, Sei J. Oh, Desmond C. Cook

Physics Faculty Publications

The relative recoilless fraction (F-value) of each of six iron oxides, defined as the ratio of the recoil-free fractions of two different materials, was experimentally determined relative to hematite at 300 K and 77 K by Mössbauer spectroscopy. Using the relative recoil-free fractions compared to that of hematite, the relative recoilless fractions between all pairs of the seven iron oxides were determined. The F-values can allow conversion of Mössbauer subspectral areas to the relative atomic, molecular, or weight fractions of each iron oxide present in a mixed oxide phase sample.

Exclusive Disjunctions In Indefinite And Maybe Information In Relational Databases, Taflan İ. Gündem

Turkish Journal of Electrical Engineering and Computer Sciences

Incorporating indefinite information into databases has been studied extensively. In this paper, we propose a structure called an E-table to represent maybe information and inclusive and exclusive disjunctions. We define the type of redundancies in E-tables and show how to eliminate them. Also we present an extended relational algebra to operate on E-tables. In this paper we expand the concepts and operations defined by Lin and Sunderraman [1] in order to accommodate exclusive disjunctions in relational databases.

Nonlinear Constrained Optimizer And Parallel Processing For Golden Block Line Search, Duc T. Nguyen, Wilson H. Tang, Yeou K. Tung, Hakizumwami B. Runesha

Civil & Environmental Engineering Faculty Publications

Generalized exponential penalty functions are constructed for the multiplier methods in solving nonlinear programming problems. The non-smooth extreme constraint Gext is replaced by a single smooth constraint Gs by using the generalized exponential function (base a>1). The well-known K.S. function is found to be a special case of our proposed formulation. Parallel processing for Golden block line search algorithm is then summarized, which can also be integrated into our formulation. Both small and large-scale nonlinear programming problems (up to 2000 variables and 2000 nonlinear constraints) have been solved to validate the proposed algorithms.

A Classification Of Techniques For The Compensation Of Time Delayed Processes. Part 1: Parameter Optimised Controllers, Aidan O'Dwyer, John Ringwood

Conference papers

An extensive literature exists on the compensation of time delayed processes. It is possible to identify themes that are common to many of the available techniques. The intention of the two parts of this paper is to provide a framework against which the literature may be viewed; Part 1 of the paper considers the use of parameter optimised controllers for the compensation problem, with Part 2 of the paper considering the use of structurally optimised compensators. Conclusions are drawn at the end of Part 2.

A Classification Of Techniques For The Compensation Of Time Delayed Processes. Part 2: Structurally Optimised Controllers, Aidan O'Dwyer, John Ringwood

Conference papers

Following on from Part 1, Part 2 of the paper considers the use of structurally optimised controllers to compensate time delayed processes.