Engineering Commons^™

A Volume Integral Formulation For Electromagnetic Scattering From Homogeneous Dielectric Bodies, Mark Joseph Povinelli

Electrical Engineering and Computer Science – Theses

In recent years, printed circuit antennas have become very useful in conformal and planar phased array antenna systems. Of particular interest is the radiation and scattering performance of stripline and microstrip printed circuit antenna array-elements used in these systems. These ele­ments are generally made up of a complex three-dimensional distribution of dielectrics and con­ductors, which can include microstrip or stripline feed circuitry on a dielectric substrate. Figure 1 shows the geometry of a typical multilayer printed circuit stripline-fed flared slot antenna, used as an array-element in a multioctave planar phased array antenna. This antenna element design also incorporates a stripline …

Variable Angle Spectroscopic Magneto-Optics And Ellipsometry: Application To Dyco Multilayers, Thomas E. Tiwald, William A. Mcgahan, Z. S. Shan, Alan M. Massengale, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

The purpose of this paper is twofold. First, we describe the adaptation of a variable angle spectroscopic ellipsometer (VASE) to magneto-optic measurements covering 3000–8000 Å, and 0 to ±8 kOe. Second, we describe application of VASE to determine Kerr rotation and ellipticity for a series of Dy/Co multilayers prepared by sputter deposition. We report spectroscopic ellipsometric and Kerr effect results for samples exhibiting perpendicular magnetic anisotropy, since these are relevant as magneto-optic recording media.

A Lagrangian For A System Of Two Dyons, Rainer Georg Thierauf

Dissertations and Theses

Maxwell's equations for the electromagnetic field are symmetrized by introducing magnetic charges into the formalism of electrodynamics. The symmetrized equations are solved for the fields and potentials of point particles. Those potentials, some of which are found to be singular along a line, are used to formulate the Lagrangian for a system of two dyons (particles with both electric and magnetic charge). The equations of motion are derived from the Lagrangian. It is shown that the dimensionality constants k and k*, which were introduced to define the units of the electromagnetic fields, have to be equal in order to avoid …

Mulch: A Multi-Layer Channel Router Using One, Two, And Three Layer Partitions, Ronald I. Greenberg, Alex T. Ishii, Alberto L. Sangiovanni-Vincentelli

Computer Science: Faculty Publications and Other Works

Chameleon, a channel router for three layers of interconnect, has been implemented to accept specification of an arbitrary number of layers. Chameleon is based on a strategy of decomposing the multilayer problem into two- and three-layer problems in which one of the layers is reserved primarily for vertical wire runs and the other layer(s) for horizontal runs. In some situations, however, it is advantageous to consider also layers that allow the routing of entire nets, using both horizontal and vertical wires. MulCh is a multilayer channel router that extends the algorithms of Chameleon in this direction. MulCh can route channels …

Thin-Film Hermeticity: A Quantitative Analysis Of Diamond-Like Carbon Using Variable Angle Spectroscopic Ellipsometry, S. Orzeszko, Bhola N. De, John A. Woollam, John J. Pouch, Samuel A. Alterovitz, David C. Ingram

Department of Electrical and Computer Engineering: Faculty Publications

The purpose of this paper is twofold. First, we report on the successful application of variable angle spectroscopic ellipsometry to quantitative thin-film hermeticity evaluation. Secondly, it is shown that under a variety of film preparations and moisture introduction conditions water penetrates only a very thin diamondlike carbon (DLC) top surface-roughness region. Thus DLC is an excellent candidate for use as protective coatings in adverse chemical and aqueous environments.

A Structured Light Method For Sensing Alignment During Automated Truss Assembly, Jayesh K. Champaneri

Electrical & Computer Engineering Theses & Dissertations

A new method using structured light is proposed to obtain visual feedback information for aligning two cylindrical beams. For a robotic system employed to perform alignment operations in real time it is essential that the accompanying vision system does not pose a heavy burden on the computing machinery and reduce the overall speed of operation. The method proposed here involves two stripes of light projected on each cylinder. One picture frame is sufficient to completely determine the position of the cylinder in space. An experiment was conducted to demonstrate the principle of this method. Results showed that the errors involved …

Reflectance Of An Absorbing Substrate For Incident Light Of Arbitrary Polarization: Appearance Of A Secondary Maximum At Oblique Incidence, R. M.A. Azzam, A. M. El-Saba

Electrical Engineering Faculty Publications

The reflectance of an absorbing substrate Rθ(ɸ) is considered as a function of the angle of incidence ϕ and an incident polarization parameter θ, where cos²θ and sin²θ give the power fractions of incident radiation that are p-and s-polarized, respectively. Taking GaAs as an example, we find that at certain wavelengths (e.g., 0.248 and 0.620 µm), the R_θ vs ɸ curve becomes oscillatory in a narrow range of θ > 45° with an unexpected secondary maximum appearing at oblique incidence. The extrema of the function R_θ(ɸ) are determined numerically, and their angular …

Variable Angle Of Incidence Spectroscopic Ellipsometric Characterization Of Tio2/Ag/Tio2 Optical Coatings, Kazem Memarzadeh, John A. Woollam, Abe Belkind

Department of Electrical and Computer Engineering: Faculty Publications

Optical constants (3000–8000 Å) and layer thicknesses of TiO₂/Ag/TiO₂ optical coatings are determined using variable angle of incidence spectroscopic ellipsometry. Ellipsometrically determined silver layer thicknesses agree well with those obtained by cross-sectional transmission electron microscopy. Also, spectral characteristics, absent in bulk silver data, are observed in n and k spectra for the thin silver layers. It is suggested that these structures may be caused by plasmon effects from the silver layers.

Waveform Analysis And Application To A Model Of The Egg Waveform, Eu-Rune Chang

Theses

The purpose of thesis is to describe and investigate a model of electroglottogram waveform. At the beginning, we generate a set of sine waveform models to analyze by using Fourier transform theory. Then, according to the electroglottogram is conjectured to be related to the area contact between the vocal folds, we assume a simple model of vocal fold vibratory motion is used to estimate the vocal fold contact area as function of time. Therefore, we modified and developed the mathematic EGG waveform model by using personal computer program computation to become a set of realistic EGG waveform models, which are …

Learning System, Bhavesh T. Adani

Theses

Many rule-based learning systems have been implemented which generate and update rules/facts from illustrative examples provided by the user. But very few of them have succeeded in achieving the efficiency and accuracy of an ideal system.

The approach made here is to continuously update the hierarchical structure of rules/facts of a knowledge-base so that efficient and accurate solutions to any query can be achieved easily and immediately from the many possible solutions to the query. As the rule-based systems deal with a very large knowledge-base, it is sometimes necessary to apply a learning technique that finds optimum solutions efficiently.

The …

Analysis And Design Of A Surface Microengineered Silicon Humidity Sensor, Uei-Yanq Chen

Theses

This thesis details the design for a solid-state humidity sensor which utilizes state-of-the-art silicon technology. The sensor design utilizes a microengineered surface which includes a polysilicon airbridge structure as heater and sensor element in an integrated device.The operation of this device depends upon the small variation of thermal convection coefficient which effects the temperature of the heated element within the device. The temperature of the polysilicon bridge is monitored by means of a resistance bridge. In one design(sensor I) a single polysilicon airbridge is used for both the heater and resistance sensing element. Also a second inferior design (sensor II) …

Optimal Cache Size In Microprocessor-Based Multiprogramming System, Charalambos Stephanou Christou

Theses

The Motorola 68020 microprocessor, its paged memory management unit MC68851 and cache memories are rigorously studied. The simulation model of this uniprocessor, multiprogramming system was constructed and tested to determine the optimal physical cache size.

The parameters varied in the model are the cache size, the degree of multitasking, the loop count and size, the cache algorithm and the time slice given to every task. A number of simulations have been conducted and the results are examined.

Arithmetic Pipline Scheduler, Chun-Ta Pan

Theses

A schedule is used to determine which stages of an arithmetic pipeline are active at any particular time. It can determine when another process can be introduced into the pipeline so no more than one set of data will use the same stage at the same time. The Arithmetic Pipeline Scheduler (APS) is a software tool used to analyze schedules for different operations and determine greedy schemes for introducing data into the pipeline. The user can use APS to process up to ten arithmetic equations. The user also can use APS to define different configurations of stages. Besides, APS can …

Computer Analysis Of The Electrocardiogram Using Hardware Digital Signal Processing, Mohammad Ashfaque Shaikh

Theses

A system based on the microcomputer IBM PC-AT has been realized to acquire and filter the clinical electrocardiogram (ECG) data in real time. The system program further detects and analyzes the ECG signals for possible cardiac arrhythmias.

This research is based on work done by previous researchers and achieves significant goals towards achieving on-line arrhythmia detection using a microcomputer. The system uses the hardware and software package ASPI 320/PC from Atlanta Signal Processors Inc. This hardware configuration uses a special purpose instrumentation microprocessor ( TMS32010 from Texas Instruments) to coprocess the ECG signals. Coprocessing the signals with the ASPI 320/PC …

Kalman Filtering Applied To The Analysis Of Brainstem Auditory Evoked Potentials, Chong An Qian

Theses

The objective of this thesis is to detect the Brainstem Auditory Evoked Response (BAER) using lower numbers of averages than at present, by using an optimal smoothing method which is based on the Kalman Filter.

By using this method, the wave V latency of the BAER which is useful in testing for hearing loss can be detected with as low as 500 averages, while the traditional signal averaging method requires at least 2000 averages. Thus the time required for a hearing loss test can be reduced from one hour to approximately 20 minutes.

Also several other methods for detecting BAER …

Estimation Of X-Band Scattering Properties Of Tree Components, David E. Pitts, Gautam D. Badhwar, Eddie Reyna, R. Zoughi, Linkim Wu, Richard K. Moore

Electrical and Computer Engineering Faculty Research & Creative Works

An X-band FM-CW very fine range resolution scatterometer was used to acquire backscattering data for individual branches for a number of tree species. Using a model to describe the scattering source function, dσ/dR = f(η, κ), and an experimental procedure for selected removal of plant parts, allows the estimation of η, the volume backscatter coefficient, and κ, the volume extinction coefficient. It is found that 1) leaves are strong attenuators as well as scatterers, 2) the albedo, ω = η/κ, at a given angle of incidence, is nearly independent of the tree type, 3) the tree …

Measurements Of Radar Backscatter From An Artificial Tree An Indication Of Azimuthal Variations And Polarisation Sensitivity Of Trees, Richard K. Moore, M. S. Osman, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

Measurements of radar backscatter from an artificial tree were made in the laboratory at 6 and 10 GHz at horizontal incidence. The system has resolution cylinder 18 cm in diameter and 11 cm long. The tree itself was only 30.5 cm high so about half the tree was within the beam. The scattering was azimuthally uniform. Tilted polarizations gave results favoring an angle corresponding with that of the branches. Measurements were made with and without leaves.

Division-Of-Wave-Front Thin-Film Beam Splitter For Generating Binary Patterns Of Orthogonal Elliptical Polarization States, R. M.A. Azzam

Electrical Engineering Faculty Publications

A division-of-wave-front thin-film beam splitter is described that reflects monochromatic light at oblique incidence with orthogonal elliptical polarization states. It consists of a metallic substrate partially covered with a transparent thin film that inverts the ratio ρ of the complex p and s reflection coefficients at the principal angle of the metal. Any pattern of coated and uncoated areas of the substrate is imprinted upon the reflected wave front as a corresponding two-dimensional spatial binary polarization pattern. A specific design is given that uses a Au substrate at a wavelength of 632.8 nm. The effects of small errors in the …

Thin-Film Devices For Polarized Light- Introduction, R. M.A. Azzam, William H. Southwell

Electrical Engineering Faculty Publications

No abstract provided.

Implementation Of A Cross Coupled Phase Locked Loop System With Closed Loop Amplitude Control, Behzad Sadeghi

Theses

A system was designed, to demodulate an FM signal in presence of an interfering signal whose frequency was very close to the desired signal, this system was implemented and tested based on the theory of cross coupled phase locked loop systems, originaly proposed by (1).

This system included two phase locked loops for the purpose of demodulation, two low pass filters and two integrators, for the purpose of amplitude estimation. Two additional phase locked loops were designed to act as a 90° phase shifter. The following is the result of the theory, design procedure and some tabulated data for this …

Clinical Base Station For Portable Patient Monitoring Equipment, Silin Kuang

Theses

In today's clinical environment, where it is not always desirable to have a computer terminal present, a microcontroller-based biomedical system with multi-purpose features is needed. The present work offers an approach for a clinical based desktop workstation that provides the physician with record files, general management of his patient group, and specific algorithms for patient or group analyses. The workstation has the capabilities to acquire a large number of data from a portable patient monitoring device, generate a hard copy graphic record, create a patient cardfile and an . office personnel loggin file, and check patient's appointment and emergency list. …

Istemcr : Integrated System For Truck Engine Monitoring Via Cellular Radio, Tse-Shan Pan

Theses

The study presented is aimed at the application of the Data Acquisition to The Truck Engine as the source of all the signals, with the mobile telephone Cellular Radio system.

A Word Based Data Compression Using Arithmetic Encoding, Christopher Dean Peckham

Theses

It is usually difficult to compress data from a statistically unknown source and yield a good compression ratio. Using the fact that words are the fundamental basis of the written language, a data compression scheme based on words should yield high compression ratios. Discussed here is a compression scheme that gathers words from the source stream and places them in a dictionary, or word list, to use later in the coding, thereby becoming adaptive to the words in a given file without prior knowledge of the source. When a word is in the word dictionary, it is encoded by its …

Data Extraction And Analysis In Glucose Monitor, Chang Qian

Theses

For the purpose of building a workstation to read and analyze data from hand-held, home use glucose monitor, a new high performance Digital Oscilloscope Peripheral (DOP) for PC is used to easy sample and store data, and it is described here. The new features of DOP are discussed and some application software packages for different purpose are described here in detail.

Since the sampled data from the hand-held, home use glucose monitor is irregular and in random form, the Least-Square Polynomial Modeling Method is used to produce a fit curve line, which best goes through most data points. Using the …

Logic Design Using Programmable Logic Devices, Loc Bao Nguyen

Dissertations and Theses

The Programmable Logic Devices, PLO, have caused a major impact in logic design of digital systems in this decade. For instance, a twenty pin PLO device can replace from three hundreds to six hundreds Transistor Transistor Logic gates, which people have designed with since the 60s. Therefore, by using PLD devices, designers can squeeze more features, reduce chip counts, reduce power consumption, and enhance the reliability of the digital systems.

This thesis covers the most important aspects of logic design using PLD devices. They are Logic Minimization and State Assignment. In addition, the thesis also covers a seldomly used but …

Extrema Of The Magnitude And The Phase Of A Complex Function Of A Real Variable: Application To Attenuated Internal Reflection, R. M.A. Azzam

Electrical Engineering Faculty Publications

Given a complex function F(ω) = |F(ω)|exp[jΔ(ω)] of a real argument ω, the extrema of its magnitude |F(ω)| and its phase Δ(ω), as functions of ω, are determined simultaneously by finding the roots of one common equation, Im[G(ω)] = 0, where G= (F′/F)² and F′ = ∂F/∂ω. The extrema of |F| and Δ are associated with Re G < 0 and Re G > 0, respectively. This easy-to-prove theorem has a wide range of applications in physical optics. We consider attenuated internal reflection (AIR) as …

Physical Mechanism Of Triggering In Trigatron Spark Gaps, F. E. Peterkin, P. F. Williams

P. F. (Paul Frazer) Williams Publications

Since the first trigatron spark gap was described by J. D. Craggs, M. E. Haine, and J. M. Meek [J. Inst. Electr. Eng. 93A, 963 (1946)], there has been controversy about the physical mechanism responsible for triggering the devices. In this letter we present experimental evidence that directly shows the sequence of physical events responsible for triggering in the gap we studied, and we present a model for trigatron triggering based on this information. We believe this model to be general and discuss it in light of existing literature. We briefly discuss the implications of the model for the engineering …

The Lunar Date Of Ramesses Ii, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Due largely to the efforts of R. A. Parker, the various calendars used in Egypt are now fairly well understood. Dates which the Egyptians expressed in both their civil and lunar calendars can sometimes be determined exactly, and the study of such dates has been extremely important in efforts to establish an accurate Egyptian chronology. However, the successful use of this method obviously depends on one's ability to reconstruct accurately the astronomical and observational conditions on which the lunar calendar was based. The author re-examined the methods used to calculate lunar dates and have suggested some ways in which those …

Assessment Of Autonomic Regulation Of Heart Rate Variability, Shaw-Jyh Shin

Dissertations

Complex demodulation, accompanied by the techniques of interpolation, detrending and zero-phase-shift lowpass filtering were used to examine the effect of both divisions of the autonomic nervous system (sympathetic and parasympathetic) on heart rate by analyzing the heart rate variability signal from dogs under two different classical conditionings: CS+ and CS-, which cause different dynamic pattern changes in the autonomic nervous system to regulate the heart rate.

Unlike power spectral analysis, complex demodulation gives results in the time domain and shows the variation of amplitude and phase over time at a given frequency. The variation of phase indicates the frequency deviation …

System Performance Criteria In Cdma Networks Using Gold Codes, Yong H. Kim

Theses

First, we have presented the autocorrelation and crosscorrelation properties for periodic and aperiodic binary sequences. The generation of binary sequences using shift registers with feedback was reviewed. We have also included correlation properties for the Gold codes.

Next, we discussed Gold code generation for the balanced and unbalanced Gold codes.

Thirdly, we investigated the number of simultaneous users in a CDMA system using Gold codes for the worst case and the average case of mutual interference.

Finally, we simulated the probability of interference exceeding a threshold value, and the average crosscorrelation value caused by interference in a CDMA network which …