Engineering Commons^™

High Order Orthogonal Tensor Networks: Information Capacity And Reliability, Donald C. Wunsch, Y. M. Mirkes, Alexander N. Gorban

Electrical and Computer Engineering Faculty Research & Creative Works

Neural networks based on construction of orthogonal projectors in the tensor power of space of signals are described. A sharp estimate of their ultimate information capacity is obtained. The number of stored prototype patterns (prototypes) can many times exceed the number of neurons. A comparison with the error control codes is made

Kramers-Kronig Anomalous Dispersion On Single-Mode Fiber-Optic Couplers And Tapers, Arnel C. Lavarias

Electrical & Computer Engineering Theses & Dissertations

The Kramers-Kronig relations couple the real and imaginary part of the dielectric constant of a medium, namely the refractive index n(ω) and the extinction coefficient κ(ω). Changes in n(ω) due to normal and anomalous dispersion (Kramers-Kronig effect) are investigated for the first time using fiber optic couplers and tapers. Kramers-Kronig effect is induced by evanescent wave absorption in these devices. Couplers and tapers have oscillatory spectral outputs that are highly sensitive to the refractive index of the surrounding medium. Theoretical modeling of the Kramers-Kronig effect on couplers and tapers shows two distinct effects. First, the spectral outputs of these devices …

Diamond For Fiber-Optic Raman Spectroscopy, Jianli Zheng

Electrical & Computer Engineering Theses & Dissertations

Raman spectroscopy is a powerful technique for molecular structural studies and concentration measurement. Being a single beam technique, the Raman intensity depends on the optical power of the excitation source, optical alignment of the system, detector response as well as species concentration. To eliminate the unwanted variations in the system and get the concentration information of the species, intensity referencing is necessary. The existing referencing methods either use a constant Raman band of the sample, or add a chemically inert material with known concentration into the sample. Unfortunately, the former method is not always applicable and the latter is not …

New Approaches To Column Compatibility Checking And Column-Based Input/Output Encoding For Curtis Decompositions Of Completely Or Incompletely Specified Switching Functions, Michael A. Burns

Dissertations and Theses

Cube calculus is an algebraic model used to process boolean functions. Cube calculus operations are widely used in logic optimization, logic synthesis, image processing and recognition, machine learning, and other applications which require massive logic operations.

The cube calculus operations can be carried out on general-purpose computers. Since these operations can involve several levels of nested loops, this approach has poor performance.

A cube calculus machine which has a special data path designed to speed up cube calculus operations is presented in this thesis. This c-qbe calculus machine can execute cube calculus operations 10 to 25 times faster than the …

The Electrodynamic Levitation Of A Collar : Analysis, Experimentation And Simulation, Philip Nixon

Theses

This dissertation describes various methods of maintaining a collar levitated in a vertical axis, using the well-known principle of electromagnetic induction between two circuits. The advantages of closing the magnetic loop around the collar, to obtain large radial flux cutting the collar and, therefore, large lifting forces for a given induced current, are considered in depth.

The ideal magnetic circuit and the equivalent electrical circuit are used in developing a model for two topologies of core (both an open and closed-circuit core) levitating a nonmagnetic conducting collar above a coil. Various affects that degrade the performance of the levitation rig …

Reflection High-Energy Electron-Diffraction Study Of Melting And Solidification Of Pb On Graphite, Z. H. Zhang, P. Kulatunga, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The melting and solidification of Pb thin films on pyrolytic graphite are investigated in situ by reflection high-energy electron diffraction. Thin films with thicknesses of 4-150 monolayers are investigated. The surface morphology of the thin films were studied by scanning electron microscopy. Superheating of the Pb thin films by 4±2 to 12±2 K is observed from diffraction intensity measurements. Upon cooling the substrate, the Pb on graphite is seen to supercool by ∼69±4 K.

Femtosecond Photoemission Study Of Ultrafast Electron Dynamics On Cu(100), J. Cao, Y. Gao, R. J. D. Miller, Hani E. Elsayed-Ali, D. A. Mantell

Electrical & Computer Engineering Faculty Publications

The energy dependence of the relaxation of photoexcited electrons in copper was measured using femtosecond time-resolved photoemission spectroscopy to within 0.3 eV above the Fermi level. By performing lifetime measurements under different surface conditions, several surface dynamical processes were investigated. In particular, an anomalous long lifetime feature, which cannot be explained with Fermi-liquid theory, was observed in the lifetime-energy curve. This feature was found originating from the photoexcitation of the strongly localized Cu 3d electrons. ©1997 American Physical Society

Microwave Plasma Chemical Vapor Deposited Diamond Tips For Scanning Tunneling Microscopy, Sacharia Albin, Jianli Zheng, John B. Cooper, Weihai Fu, Arnel C. Lavarias

Electrical & Computer Engineering Faculty Publications

Diamond microparticles were grown on etched tungsten wires using a microwave plasma-assisted chemical vapor deposition process. The apexes on cubo-octahedral particles bound by {100} and {111} facets were effectively used as tunneling tips for scanning tunneling microscopy. The atomically resolved surface image of highly oriented pyrolytic graphite was acquired. Tunneling characteristics revealed a higher electron emission from the diamond tips than that from the platinum–iridium tips. The same diamond tips were used to produce surface indentation and its image. © 1997 American Institute of Physics.

Cualse² Thin Films Obtained By Chalcogenization, S. Marsillac, K. Benchouk, C. El Moctar, J. C. Bernède, J. Pouzet, A Khellil, M. Jamali

Electrical & Computer Engineering Faculty Publications

CuAlSe₂ thin films have been synthesized by chalcogenization of thin Cu and Al layers sequentially deposited by evaporation under vacuum. It is shown that CuAlSe₂ films are obtained with some Cu₂-_δSe and Se phases present at the surface. These surface phases are suppressed by annealing under vacuum and by chemical etching in a KCN solution. At the end of the process, the XRD spectrum demonstrates that textured CuAlSe₂ films have been obtained with preferential orientation of the crystallites along the (112) direction. The gap of the films is 2.7 eV as expected. The …

Optical And Electrical Properties Of Cualse² Thin Films Obtained By Selenization Of Cu/Al/Cu... Al/Cu Layers Sequentially Deposited, J. C. Bernède, S. Marsillac, C. El Moctar, A. Conan

Electrical & Computer Engineering Faculty Publications

Optical and electrical properties of CuAlSe₂ thin films obtained by selenization of Cu/Al/Cu...Al/Cu layers sequentially deposited have been investigated. It is shown that the expected energy gap (2.67 eV) is measured for well crystallized films, whereas a slightly higher value is measured for films not so well crystallized. Raman diffusion also shows differences between well and poorly crystallized films with peaks corresponding to the reference powder for the former samples. A p-type conductivity is found whatever the crystalline quality of the samples. The conductivity of the films depends also strongly on their crystalline properties. When the films are badly …

Radar Backscatter Measurement Accuracy For A Spaceborne Pencil-Beam Wind Scatterometer With Transmit Modulation, David G. Long, Michael W. Spencer

Faculty Publications

Scatterometers are remote sensing radars designed to measure near-surface winds over the ocean. The difficulties of accommodating traditional fan-beam scatterometers on spacecraft has lead to the development of a scanning pencil-beam instrument known as SeaWinds. SeaWinds will be part of the Japanese Advanced Earth Observing Satellite II (ADEOS-II) to be launched in 1999. To analyze the performance of the SeaWinds design, a new expression for the measurement accuracy of a pencil-beam system is required. In this paper the authors derive a general expression for the backscatter measurement accuracy for a pencil-beam scatterometer which includes the effects of transmit signal modulation …

Teasing Apart The Threads Of Staple Strength, Andrew Peterson

Journal of the Department of Agriculture, Western Australia, Series 4

A successful partnership between two local inventors and Agriculture WA's Wool Program has created a new instrument which, just like the growth rings of trees, can show seasonal changes in the fibre diameter of wool. This will have considerable value to the wool industry as Andrew Peterson explains.

Damage Detection Of Bridge-Like Structures Using State Space Models, Javier Valentin Sivico

Masters Theses

"A global damage detection algorithm for bridge-like structures is proposed. This method provides the capability of determining the reduction in both stiffness and damping parameters of the structural elements. It is assumed the mass of the structural elements is not affected by the damages, which is a reasonable assumption for bridge-like structures. The proposed method uses the state space representation of the structural dynamics to make the diagnosis of the structural integrity. Given that the state space representation of any system is not unique, the damage detection procedure is developed for the physical coordinates of the state space representation. A …

Modeling Of Fading Dynamics For The Indoor Microwave Channel, Mangeet Singh

Theses : Honours

This report outlines the multipath fading phenomenon and its relationship to wireless system design. The work was conducted for the academic year of 1996. This report provides the reader with an insight into the phenomenon called fading and its relevance when designing wireless systems. Fading is an important consideration when wireless systems are to be designed. Because fading is very unpredictable and it cannot to totally eliminated in a wireless system, systems engineers have a hard time trying to design and commission efficient communication systems for a particular environment. Over the years, there has been a existing need worldwide to …

Closed Loop Time Domain Gradient Methods For Parameter And Time Delay Estimation, M, Behan, M Cahill, M. Carry, G Clausen, V. Dooley, N. English, W. Grainger, D. O'Connor, Aidan O'Dwyer, John Ringwood

Conference papers

This paper discusses the estimation of process parameters and time delay, in a Smith predictor structure, using gradient algorithms in the time domain. A number of estimation algorithms are outlined and applied in simulation to the estimation of the parameters of an appropriate process model. An analytical exploration of the technique is also provided.

Prediction Of Yarn Strength From Fiber Properties Using Fuzzy Artmap, Raonak Zaman, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

The count-strength-product (CSP) of cotton yarn is a complex function of fiber properties and spinning performance. The traditional way of predicting yarn CSP is using linear multiple regression. The correlation coefficient between actual CSP and predicted CSP obtained from linear regression is almost always less than 0.9. In this paper, we used a Fuzzy ARTMAP network to predict yarn CSP from fiber properties and spinning performance. Fiber properties and spinning data were used as inputs to ART_a, and yarn CSP was used as ART_b input. Our objectives are: better prediction of the quality of the end product, …

Safety Analysis Of Redundant Systems Using Fuzzy Probability Theory, James P. Dunyak, Ihab W. Ssad, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Backpropagation Of Accuracy, Donald C. Wunsch, M. Yu Senashova, Alexander N. Gorban

Electrical and Computer Engineering Faculty Research & Creative Works

We solve the problem: how to determine maximal allowable errors, possible for signals and parameters of each element of a network, proceeding from the condition that the vector of output signals of the network should be calculated with given accuracy? "Backpropagation of accuracy" is developed to solve this problem

Reflection Anistropy Spectroscopy Study Of The Near Surface Electric Field In Low-Temperature Grown Gaas (001), Todd Holden, Fred H. Pollak, J. L. Freeouf, D. Mcinturff, J. L. Gray, Mark S. Lundstrom, J. M. Woodall

Department of Electrical and Computer Engineering Faculty Publications

We have evaluated an ‘‘effective depletion width’’ of =< 45 Å and the sign (n-type/upward band bending) of the near surface electric field in low-temperature grown GaAs ~001! using the optical method of reflection anisotropy spectroscopy in the vicinity of the spin-orbit split E₁ , E₁ + Delta₁ optical features. Our results provide evidence that surface Fermi level pinning occurs for air exposed (001) surfaces of undoped low temperature grown GaAs.

Technique For Measurement Of The Minority Carrier Mobility With A Bipolar Junction Transistor, S. L. D'Souza, Michael R. Melloch, Mark S. Lundstrom, E. S. Harmon

Department of Electrical and Computer Engineering Faculty Publications

A simple technique to measure the minority carrier mobility using a bipolar junction transistor is demonstrated. By fixing the base-emitter voltage, the carrier injection into the base is constant. The collector current is then monitored as a function of a magnetic field applied perpendicular to the current transport across the base. The magnetic field leads to an increase in base transit time and a corresponding decrease in collector current. From the resulting fractional change in collector current, the minority carrier mobility in the base can be determined. For narrow base transistors, quasiballistic transport across the base must be taken into …

Electrical Characteristics Of Nearly Relaxed Inas/Gap Heterojunctions, E H. Chen, T. P. Chin, J. M. Woodall, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The electrical properties of lattice mismatched InAs/GaP heterojunctions are examined. In spite of a high dislocation density at the heterointerface, the current versus voltage characteristics show nearly ideal behavior with low reverse leakage currents and high breakdown voltages. The forward currentvaried exponentially with bias displaying ideal factors of 1.10 or less. Band offsets estimated from current–voltage and capacitance–voltage analysis are consistent with previous estimates based on differences in Schottky barrier heights.

The Sol Of New Orleans: An Undergraduate Design Experience, Edit J. Kaminsky, Brian L. Hardouin

Electrical Engineering Faculty Publications

This paper presents the incorporation of the design, construction, and testing of a solar-powered car into the undergraduate curriculum of the Electrical Engineering Department of the University of New Orleans. All work on the vehicle is entirely performed by students who earn design credits in our Senior EE Design Project and/or Special Problems in EE courses.

Estimation Of Surface Snow Properties Using Combined Millimeter-Wave Backscatter And Near-Infrared Reflectance Measurements, Ram M. Narayanan, Sandy R. Jackson

Department of Electrical and Computer Engineering: Faculty Publications

Knowledge of surficial snow properties such as grain size, surface roughness, and free-water content provides clues to the metamorphic state of snow on the ground, which in turn yields information on weathering processes and climatic activity. Remote sensing techniques using combined concurrent measurements of near-infrared passive reflectance and millimeter-wave radar backscatter show promise in estimating the above snow parameters. Near-infrared reflectance is strongly dependent on snow grain size and free-water content, while millimeter-wave backscatter is primarily dependent on free-water content and, to some extent, on the surface roughness. A neural-network based inversion algorithm has been developed that optimally combines near-infrared …

Manual Tracking Flight Control With Amplitude And Rate Constrained Dynamic Actuators, Russel B. Miller

Theses and Dissertations

A new control methodology for manual flight control, viz., real-time tracking control, is developed. Amplitude and rate constrained dynamic actuators are considered. Optimal tracking control is made possible by the use of unique reference signal prediction strategies which extrapolate the reference signal over the optimization horizon. A receding horizon, linear-quadratic inner-loop controller is employed in conjunction with an outer-loop nonlinear element. The constraint effects mitigation strategy is to optimally track a modified reference signal which yields feasible actuator commands over the optimization horizon when the pilot demanded reference is too aggressive to be tracked by the inner-loop optimal control law. …

New Objective Classification System For Nuclear Opacification, Donald D. Duncan, O. B. Shukla, Sheila West, Oliver D. Schein

Electrical and Computer Engineering Faculty Publications and Presentations

We have developed an autonomous objective classification scheme for degree of nuclear opacification. The algorithm was developed by using a series of color 35-mm slides acquired with a Topcon photo slit-lamp microscope and use of standard camera settings. The photographs were digitized, and first, and second-order gray-level statistics were extracted from within circular regions of the nucleus. Classifications of severity were performed by using these features as input to a neural network. Training versus classification performance was tested by using photographs of different eyes, and test/retest classification reproducibility was evaluated by using paired photographs of the same eyes. We demonstrate …

Parallel Algorithms For Single-Layer Channel Routing, Ronald I. Greenberg, Shih-Chuan Hung, Jau-Der Shih

Computer Science: Faculty Publications and Other Works

We provide efficient parallel algorithms for the minimum separation, offset range, and optimal offset problems for single-layer channel routing. We consider all the variations of these problems that are known to have linear- time sequential solutions rather than limiting attention to the "river-routing" context, where single-sided connections are disallowed. For the minimum separation problem, we obtain O(lgN) time on a CREW PRAM or O(lgN / lglgN) time on a (common) CRCW PRAM, both with optimal work (processor- time product) of O(N), where N is the number of terminals. For the offset range problem, we obtain the same time and processor …

Investigation Of The Ferrielectric Subphase With Qt>1/2 Under Bias Voltage, Yuri Panarin, O.E. Kalinovskaya, J.K. Vij

Articles

The properties of Femelectric phase with qT > 112 have been investigated using broadband dielectric spectroscopy and polarization measurements under the bias voltage. The field -induced sequence of phase transitions is found to be different fiom those of the conventional femelectric phases with qTS 112

A Study Of Antiferroelectric Liquid Crystals Using The Pyroelectric Technique, J.W. O'Sullivan, Yuri Panarin, J.K. Vij, A.J. Seed, M. Hird, J.W. Goodby

Articles

Antiferroelectric liquid crystals are studied using the pyroelecmc technique. The effects of temperature and applied voltage on the pyroelectric signal are examined. The pyroelecmc signal can detect phase changes that occur due to temperature and bias voltage. A high temperature femelecmc phase FiLC is found and the stability of this phase under different bias voltages is examined

Tradeoffs In The Design Of A Spaceborne Scanning Pencil Beam Scatterometer: Application To Seawinds, David G. Long, Chialin T. Wu, Michael W. Spencer

Faculty Publications

SeaWinds is a spaceborne wind scatterometer to be flown on the second Japanese Advanced Earth Observing Satellite (ADEOS-II) in 1999. An important international element of NASA's Earth Observing System (EOS), SeaWinds is an advanced follow-on to the NASA scatterometer (NSCAT) on the first ADEOS platform. Unlike previous operational spaceborne scatterometer systems. SeaWinds employs a scanning "pencil-beam" antenna rather than a "fan-beam" antenna, making the instrument more compact and yielding greater ocean coverage. The goals of this paper are twofold. First, the overall SeaWinds functional design and backscatter measurement approach are described, and the relative advantages of the pencil-beam technique are …

The People: The Least Accountable Branch, Marci A. Hamilton

Articles

No abstract provided.