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Thermodynamic Modeling, Energy Equipartition, And Nonconservation Of Entropy For Discrete-Time Dynamical Systems, Wassim H. Haddad, Qing Hui, Sergey G. Nersesov, Vijaysekhar Chellaboina

Department of Electrical and Computer Engineering: Faculty Publications

We develop thermodynamic models for discrete-time large-scale dynamical systems. Specifically, using compartmental dynamical system theory, we develop energy flowmodels possessing energy conservation, energy equipartition, temperature equipartition, and entropy nonconservation principles for discrete-time, large-scale dynamical systems. Furthermore, we introduce a new and dual notion to entropy; namely, ectropy, as a measure of the tendency of a dynamical system to do useful work and grow more organized, and show that conservation of energy in an isolated thermodynamic system necessarily leads to nonconservation of ectropy and entropy. In addition, using the system ectropy as a Lyapunov function candidate, we show that our discrete-time, …

A Review Of Antennas And Propagation For Mimo Wireless Communications, Michael A. Jensen, Jon W. Wallace

Faculty Publications

Multiple-input-multiple-output (MIMO) wireless systems use multiple antenna elements at transmit and receive to offer improved capacity over single antenna topologies in multipath channels. In such systems, the antenna properties as well as the multipath channel characteristics play a key role in determining communication performance. This paper reviews recent research findings concerning antennas and propagation in MIMO systems. Issues considered include channel capacity computation, channel measurement and modeling approaches, and the impact of antenna element properties and array configuration on system performance. Throughout the discussion, outstanding research questions in these areas are highlighted.

Wide Angle Decentered Lens Beam Steering For Infrared Countermeasures Applications, Jennifer L. Gibson, Bradley D. Duncan, Edward A. Watson, John S. Loomis

Electro-Optics and Photonics Faculty Publications

A beam-steering system consisting of three cemented achromatic doublets is presented. Intended for use in IR countermeasure applications, our system is designed to operate over the 2- to 5-μm spectrum with minimum angular dispersion. We show that dispersion can be minimized by using doublet lenses fashioned from AMTIR-1 and germanium. Our system is designed to be compact and lightweight, with no internal foci, while allowing steering to ±22.5 deg. We also maintain a minimum 2-in. clear aperture for all steering angles, and a nominal divergence of 1 mrad. Plane wave and Gaussian beam analyses of our system are presented.

Electrical Material Property Measurements Using A Free-Field, Ultra-Wideband System [Dielectric Measurements], C. A. Grosvenor, R. Johnk, D. Novotny, S. Canales, J. Baker-Jarvis, M. Janezic, James L. Drewniak, Marina Koledintseva, Jianmin Zhang, Poorna Chander Ravva

Electrical and Computer Engineering Faculty Research & Creative Works

We present nondestructive measurements of material properties using TEM horn antennas and an ultra-wideband measurement system. Time-domain gating and genetic algorithms are used to process the data and extract the dielectric properties of the material under test.

Probabilistic Balancing Of Fault Coverage And Test Cost In Combined Built-In Self-Test/Automated Test Equipment Testing Environment, Shanrui Zhang, Minsu Choi, Nohpill Park, Fabrizio Lombardi

Electrical and Computer Engineering Faculty Research & Creative Works

As design and test complexities of SoCs ever intensify, the balanced utilization of combined built-in self-test (BIST) and automated test equipment (ATE) testing becomes desirable to meet the required minimum-fault-coverage while maintaining an acceptable cost overhead. The cost associated with combined BIST/ATE testing of such systems mainly consists of 1) the cost induced by the BIST area overhead and 2) the cost induced by the overall testing time. In general, BIST is significantly faster than ATE, while it can provide only limited fault-coverage, and driving higher fault-coverage from BIST means additional area cost overhead. On the other hand, higher fault-coverage …

Huffman Approach To Opcode Compression, Jason B. Shreve

Electrical & Computer Engineering Theses & Dissertations

Instructions are the building blocks of computer programs. They are composed of opcodes, which uniquely identify each instruction, and the operands or data. In most architectures, the instruction length is a set multiple of the word size. The size and number of operands vary by instruction. Due to programmer usage, program need, or compiler design, opcodes do not occur with a constant distribution. Likely, some opcodes occur very frequently, whereas others occur very infrequently or not at all. If the length of an opcode were representative of its frequency, compression in program size might be achieved.

This thesis is an …

Achromatic Angle-Insensitive Infrared Quarter-Wave Retarder Based On Total Internal Reflection At The Si–Sio2 Interface, R. M.A. Azzam, Cristina L. Spinu

Electrical Engineering Faculty Publications

An achromatic infrared (λ = 1.2–4 μm), Si-prism quarter-wave retarder (QWR) is described that uses total internal reflection at a buried Si–SiO₂ interface at an angle of incidence φ near 33°, where ∂Δ/∂φ = 0. The retardance Δ deviates from 90° by <±2° within a field of view of ±10° (in air) over the entire bandwidth. Because the SiO₂ layer at the base of the prism is optically thick, this QWR is unaffected by environmental contamination.

Lorentz-Violating Electrostatics And Magnetostatics, Quentin G. Bailey, V. Alan Kostelecký

Publications

Electromagnetostatics experiments show promise for improving existing sensitivities to parity-odd coefficients for Lorentz violation in the photon sector.

Swing-Up And Balancing Nonlinear Control For A Rotational Inverted Pendulum, Jiang Wang

Mechanical & Aerospace Engineering Theses & Dissertations

In this thesis, nonlinear controllers are designed for the swing-up and balance modes of a rotational inverted pendulum, which is a pendulum hinged on a horizontally rotating link. The proposed control algorithms are designed by partial feedback linearization and sliding mode control techniques, for swing-up and balancing respectively. First a mathematical model of the pendulum dynamics is derived, followed by experimental verification. Then the system model is partially linearized, which makes it possible for the system to track a simple desired trajectory with "pump energy" function. Then a swing-up controller is designed. For an under-actuated mechanical system, like the inverted …

Modeling And Simulation Of Photonic Crystal Fibers Using Finite Difference Frequency Domain Method, Md. Khalid Ikram

Electrical & Computer Engineering Theses & Dissertations

Photonic crystal fibers (PCFs) allow guiding light in low-index core. These fibers exhibit properties such as single-mode operation in broad wavelength region. The mode shape and group velocity dispersion can be controlled by designing the microstructures of the cladding. In order to study these properties, a fast, efficient, and highly accurate numerical modeling method is required.

A full-vectorial finite-difference frequency-domain (FDFD) method is implemented. The modal properties of conventional step index fiber and index-guiding PCF are analyzed using this modeling technique. Compared to plane wave expansion and biorthogonal basis methods, FDFD is found to be simple, reliable, and efficient. PCFs …

Hierarchical Hybrid Multicast An End System Multicast Algorithm Approach, Guillermo Loaisiga

Electrical & Computer Engineering Theses & Dissertations

Due to the rapid development in the computer and communication technologies, the Internet is experiencing an increasing demand of high-speed, real-time distributed applications, such as live streaming multimedia, videoconferencing, distributed simulations, and multiparty games. Multicast is an efficient transmission mechanism to support these applications. Historically, IP Multicast (IPM) has provided multicast support with well-known benefits, especially in bandwidth savings. However, it has experienced little deployment due to economic and architectural limitations.

Overlay multicast holds promise for the implementation of large scale Internet multicast services. An overlay network is a virtual topology constructed on top of the Internet infrastructure. This concept …

Establishing A Cyber Warrior Force, Scott D. Tobin

Theses and Dissertations

Cyber Warfare is widely touted to be the next generation of warfare. As America's reliance on automated systems and information technology increases, so too does the potential vulnerability to cyber attack. Nation and non-nation states are developing the capability to wage cyber warfare. Historically, the Air Force and DoD have concentrated their efforts toward defensive network operations. However, a shift in doctrine has shown both the Air Force and DoD acknowledging the potential for Information Warfare. What appears to be lacking is the trained and educated cyber warrior force that will carry out the information operations if needed. This research …

Volume Holographic Recording And Readout For 90-Deg Geometry, Partha P. Banerjee, Monish Ranjan Chatterjee, Nickolai Kukhtarev, Tatiana Kukhtareva

Electrical and Computer Engineering Faculty Publications

When a prerecorded cross-beam hologram is reconstructed (so-called edge-lit readout) with a uniform plane wave and a point source, the resulting exact solutions reveal Bessel-function-type diffracted beam profiles, which are fundamentally modified under weak propagational diffraction. The case of a profiled beam readout with propagational diffraction may be analyzed using a transfer function approach based on 2-D Laplace transforms. In a second series of investigations, dynamic readout from a cross-beam volume hologram recorded with two orthogonal uniform plane waves is considered for various dependences of the refractive index modulation with intensity. Typically, refractive index profiles that are proportional to the …

A Fast And Simple Algorithm For Computing M Shortest Paths In Stage Graph, M. Sherwood, Laxmi P. Gewali, Henry Selvaraj, Venkatesan Muthukumar

Electrical & Computer Engineering Faculty Research

We consider the problem of computing m shortest paths between a source node s and a target node t in a stage graph. Polynomial time algorithms known to solve this problem use complicated data structures. This paper proposes a very simple algorithm for computing all m shortest paths in a stage graph efficiently. The proposed algorithm does not use any complicated data structure and can be implemented in a straightforward way by using only array data structure. This problem appears as a sub-problem for planning risk reduced multiple k-legged trajectories for aerial vehicles.

Map Estimation For Hyperspectral Image Resolution Enhancement Using An Auxiliary Sensor, Russell C. Hardie, Michael T. Eismann, Gregory L. Wilson

Electrical and Computer Engineering Faculty Publications

This paper presents a novel maximum a posteriori (MAP) estimator for enhancing the spatial resolution of an image using co-registered high spatial-resolution imagery from an auxiliary sensor. Here we focus on the use of high-resolution panchomatic data to enhance hyperspectral imagery. However, the estimation framework developed allows for any number of spectral bands in the primary and auxiliary image. The proposed technique is suitable for applications where some correlation, either localized or global, exists between the auxiliary image and the image being enhanced. To exploit localized correlations, a spatially varying statistical model, based on vector quantization, is used. Another important …

Volume Holographic Optical Elements, Ching-Cherng Sun, Partha P. Banerjee

Electrical and Computer Engineering Faculty Publications

The final two papers are concerned with the analysis of novel holograms. Banerjee et al. investigate holographic recording and reconstruction for edge-lit holograms recorded in a 90-degree geometry. Various cases of recording and readout that incorporate propagational diffraction have been modeled. It is shown that the 90-degree geometry can result in beam shaping, as evidenced through preliminary experimental results with photorefractive lithium niobate. Nguyen et al. propose a new approach for designing computer-generated holograms. An artificial neural network is used to initiate the genetic algorithm so that the high computation cost of genetic algorithms for synthesizing holograms is significantly reduced …

Satellite Attitude Control System Design Using Reaction Wheels, Bhanu Gouda, Brian Fast, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

No abstract provided.

A Tightly-Coupled Ins/Gps Integration Using A Mems Imu, Jonathan M. Neu

Theses and Dissertations

Micro-Electro-Mechanical Systems (MEMS) technology holds great promise for future navigation systems because of the reduced size and cost of MEMS inertial sensors relative to conventional devices. Current MEMS devices are much less accurate than standard inertial sensors, but they can still be useful. In this thesis, data was recorded from an inexpensive MEMS inertial measurement unit and integrated with GPS measurements using a tightly-coupled Kalman filter. The overall goal of this research is to investigate the usefulness of MEMS sensors for a small, real-time, low-cost INS/GPS integration. A golf cart was used to collect dynamic data, along with a commercial …

Synergisms Of Electric Or Electromagnetic Fields And Photodynamic Effects Induce Apoptosis And Necrosis Of Cancer Cells, Radeva Maria, Lambrera Maya, Angelova Plamena, Traitcheva Nelly, Berg Hermann

Journal of Electrochemistry

Weak pulsating sinusoidal electromagnetic fields (PEMF) have been applied to change membrane permeation and induction of apoptosis (necrosis). In the case of suspension of human cancer cells U-937 and K-562 inside of Helmholtz-coils the amplitude of PEMF B=10 and at 39mT (at 50 Hz) was combined gradually with the cytotoxic agent actinomycin-C on one hand with its novel photodynamic activity on the other.

Electrochemical Reduction Of Nitrobenzene On The Wc Electrode In Acidic Solution, Chun-An Ma, You-Qun Chu, Ying-Hong Zhu, Zhi-Hua Xu

Journal of Electrochemistry

The tungsten carbide (WC) electrode was constructed by using polyterafluoroethylene as binder. The electrochemical behavior of nitrobenzene on the WC electrode in acidic solution was investigated by cyclic voltammetry, linear scan method and chronoamperometry. Experimental results showed that WC electrode had good activity for the electrochemical reduction of nitrobenzene, and the electrode process was controlled by diffusion and electrochemical stepssimultaneously. The apparent active energy of the electrode process is 23.7kJ⋅mol^-1, while the active energy of the electrochemicalstep is 10.91kJ⋅mol^-1.

Solid State Synthesis And Electrocatalysis Of Pt/Moo3 For The Oxidation Of Methanol, Qing Wang, Yi-Ming Zhou, Yang Shao, Yi-Gang Ji, Juan Xu, Ya-Wen Tang, Tian-Hong Lu, Tao Shen

Journal of Electrochemistry

The electrocatalyst, Pt/MoO₃ synthesized by solid state reaction, was used for the oxidation of methanol in direct methanol fuel cells. The X-Ray diffraction and cyclic voltammetry were employed to investigate the performance of the material. It was shown that the typical diffraction peaks for Pt appeared in XRD. And a good electrocatalysis for methanol oxidation was observed. The peak potential of the methanol oxidation appeared at ca. 0.63V(vs.SCE) and the peak current density for the oxidation was 78.1 mA⋅cm^-2.

Study On An Intermediate Temperature Planar Solid Oxide Fuel Cell, Shao-Rong Wang, Wen-Xia Chen, Ting-Lian Wen, Jia-Di Cao, Zhi-Yi Lv, Da-Qian Wang

Journal of Electrochemistry

Tape cast method was applied to prepare green sheets of Ni/YSZ anode supported YSZ thin film. After isostatic pressure treatment and cosintering, the YSZ film on the Ni/YSZ anode was gas-tight dense, and 15~30 μm thick. The area of the composite film was over 100 cm². A Ce_0.8Sm_0.2O_1.9 (CSO) interlayer was sintered on to the YSZ electrolyte film to protect La_0.6Sr_0.4CoO₃ (LSCO) cathode from reaction with YSZ at high temperatures. The LSCO cathode layer was screen printed onto the CSO interlayer and sintered at 1200 ℃ for 3 …

Fabrication Of Solid Oxide Fuel Cells And Analysis Of Their Structure And Performance, Nai-Tao Yang, Bo Meng, Ru-Jun Yu, Xiao-Yao Tan

Journal of Electrochemistry

An intermediate temperature solid oxide fuel cell (IT-SOFC) was fabricated by co-copressing-sintering methods, and the electrolyte of Ce_0.8Gd_0.2O_1.9 (CGO) and cathode materials of La_0.6Sr_0.4Co_0.2Fe_0.8O_3-α (LSCF) were prepared by sol-gel method. The effect of preparation methods on the microstructure of the prepared fuel cells was analyzed by SEM . It shows that the cells prepared by the co-pressing/co-sintering method possess a dense electrolyte layer and a compact interface between electrolyte and anode but a curved configuration, while those prepared by the colloidal technique have a flat configuration …

A Dual-Cell Technique And Its Application In Electrocatalytic Study Of Pt-Ru Metals, Lei Su, Bing-Liang Wu

Journal of Electrochemistry

Two local electrochemical reactive interfaces are established using two strips of Nafion membrane separated each other, which are in contact with different surface regions of the same metal-sheet working electrode. One potentiostatis used to control thepotentialof one electrochemical reactive interface to generate adsorbed surface speciesand the other potentiostatto hold the potential of the second interface as a detector of the intermediate. The adsorbed surface species driven by the difference in surface concentration diffuses alongthe surface of the metal-sheet between both local electrochemical interfaces and can be detected at the second interface when they achieveover there.The surface diffusion coefficient of the …

Preparation And Electrochemical Performance Of New Composite Seperators For Lithium-Ion Batteries, Hu Cheng, Hong-Yan Du, Yong Yang

Journal of Electrochemistry

New composite seperators for lithium ion batteries were prepared by coating PEO mixed with nanosize SiO₂ onto microporous polypropylene(PP) seperators. Highly conductive electrolytes were prepared by soaking them in an electrolyte solution. With these composite separators, the lithium ion cell consisting of Li anode and LiNi_0.8Co_0.2O₂ cathode were assembled. The high initial discharge capacity and good capacity retention were obtained through the cell.

Synthesis Of (S)-3-Phenylpropane-2-Tert-Butoxycarbonylamino-1-Thiol And Its Electrochemical Behavior Self-Assembled On Gold, Ru Sun, Jian-Feng Ge, Mei Wang, Ren-Ao Gu

Journal of Electrochemistry

The synthesis of (S)-3-Phenylpropane-2-tert-butoxycarbonylamino-1-thiol(N-Boc-APT) from L-phenylalanine was reported. L-Phenylalanine was reduced to the corresponding amino alcohol, protection of the amino group using tert-butyl pyrocarbonate gave (S)-2-tert-butoxycarbonylamino-3-phenylpropane-1-ol, which was then O-mesylated and treated with potassium thioacetate in DMF to give 3-phenylpropane-2-tert- butoxycarbonylamino-1-etylmercapto. After the acetyl group was removed with ammonia in alcohol, the desired target molecular was obtained. The structure of intermediate and target molecular was conformed by IR and ¹HNMR. We made N-Boc-APT self-assemble-modificated gold electrode and investigated its electrochemical behavior. The CV results of methylene blue on nano-Au/N-Boc-APT SAM/Au electrode showed that nano-Au could speed this electron transfer …

Synthesis And Electrochemical Behavior Of Layered-Structure Limn1-XCrXO2, Jie Xiao, Hui Zhan, Yun-Hong Zhou

Journal of Electrochemistry

The Layered-structure LiMn_1-xCr_xO₂(x=0, 0.15) solid solution has been prepared by the rheological phase method. From the XRD results, undoped LiMnO₂ crystallized almost entirely in the orthorhombic phase while the structure of LiMn_0.85Cr_0.15O₂ belongs to monoclinic phase. TEM investigation shows that the final powder product consists of ultrafine spherical particles which are distributed homogeneously, with the average diameter ranging from 60 to 300nm. The initial discharge capacity of LiMn_0.85Cr_0.15O is much higher than that of undoped LiMnO₂. After 40 cycles, the capacity retention …

Lithium Insertion Into Tio2(B) Nanobelts Synthesized By The "Soft Chemical" Method, Cha-Geng Nie, Zheng-Liang Gong, Lan Sun, Juan Zuo, Yue-Kun Lai, Chang-Jian Lin

Journal of Electrochemistry

TiO₂(B) Nanobelts were synthesized by using the "Soft chemical"method. The products were characterized by means of transmission electron microscope(TEM), X-ray diffraction(XRD), Raman spectrum and energy dispersive spectrum(EDS). Galvanostatic charging and discharging tests showed that lithium-ion intercalation/deintercalation occurred reversibly in the TiO₂(B) nanobelts electrode, and a high capacity (265 mAh·g^-1) can be obtained. The results suggested that TiO₂(B) Nanobelts might be a promising negative electrode material of second Lithium battery.

Preliminary Study Of Speek Membranes For Direct Methanol Fuel Cells Application, Su-Zhen Ren, Zhen-Xing Liang, Xin-Sheng Zhao, Qin Xing, Gong-Quan Sun, Xue-Feng Yang

Journal of Electrochemistry

This paper describes the methanol permeability characterization of SPEEK membranes and their feasibility for DMFC application. The SPEEK membranes showed a significant lower methanol permeation than Nafion 115 determined from voltammetric methods. An increase in open circuit voltage was found in the performance of SPEEK membranes in DMFC. The power density of the cell using SPEEK membrane was considerably poorer than that of Nafion 115. If modified properly, the SPEEK membranes can be chosen for DMFC application based on this study.

Nonlinear Dynamic Analysis Of An Orthotropic Composite Rotor Blade, Ming-Hung Hsu

Journal of Marine Science and Technology–Taiwan

This work presents the nonlinear dynamic analysis of orthotropic composite rotor blade using differential quadrature method (DQM). It can be found that the same efficient and procedure of DQM for both uniform composite beam and pre-twisted non-uniform composite beam. In this approach, only nine sample points are needed to achieve convergence. Dynamic responses of orthotropic composite rotor blade with various rotor rotation speeds are determined. Both linear and nonlinear dynamic responses have been obtained in order to study the significance of the nonlinear effect. The transient responses of the derived systems are calculated by using Newmark method. The bending-torsion coupled …