Electrical and Electronics Commons^™

The Applicability Of Parametric Inverse Scattering For Optical Waveguides With Imperfect Boundaries, Hyoung Jin Choi

Theses

In this thesis, the applicability of an inverse scattering technique for an optical waveguide with imperfect boundaries is investigated. The inversion of imperfect boundaries of waveguides is different from usual inverse scattering algorithms because only eigenmodes can propagate in a waveguide. We suggest a parametric inversion method based on the first-order coupled mode equation. The validity and usefulness of the method are demonstrated using examples of periodic and almost periodic imperfect boundaries.

Adaptive Subband Video Coding With Motion Compensation, Manjunatha S. Kadur

Theses

An efficient scheme for video sequence coding is presented here. The interframe redundancy present in the video sequence is exploited by motion compensation using the efficient independent orthogonal search technique, which requires least number of computations in the worst case. The motion compensated frame difference signal is encoded with a new technique — subband adaptive vector quantization.

Subband coding like transform coding results in signals of unequal energy patterns, which is efficiently utilized for bit allocation. In addition, the subband approach offers means for efficient (but suboptimal) Vector Quantization (VQ) by splitting the signal into several signals. By rate distortion …

Integrated Voice/Data Services On Multihop Radio Networks, Chialun Lu

Theses

Integrated voice/data is the first step toward Integrated Services Digital Networks (ISDN). Various techniques have been proposed and analyzed for multiplexing voice and data over a large bandwidth channel. Network efficiency is what we are most concerned about. In this paper, we address the problem of determining optimal access policies for a tandem ISDN network by using Dynamic Programming. Computer simulation shows that optimal policy minimizes the data delay.

User Interactive Compensation For Si/So Systems Via Root-Locus, Shih-Mim Liu

Theses

A powerful computer-aided root-locus method is described and applied to the compensation for SI/SO systems. The approach is based on the concept of continuation methods in which the solution of a parameterized family of algebraic problems is converted into the solution of a differential equation and incorporates the quadratic synthetic division technique. The root-locus is obtained in a systematic manner by numerical integration. Breakaway points are analyzed and classified according to the properties of higher order derivatives. A Turbo Pascal(4.0) program which utilizes the algorithm has been written.

Nonlinear Variants Of The Least Mean Square (Lms) Algorithm, John George Van Saders

Theses

Adaptive systems using the LMS algorithm or its variants usually require bilinear correlation multipliers with high dynamic range and large bandwidth. The class of LMS-type algorithms utilizing zero-memory limiters (on one or both correlation multiplier inputs) to reduce dynamic range are examined. The correlator limiters may be included to simplify the hardware implementation or may arise due to limited dynamic range of the loop components. The application of a theorem due to Price provides a technique for simplifying the analysis, which otherwise might be extremely difficult. The analysis provides closed-form expressions for the mean weight convergence behavior, permitting examination of …

Arithmetic Pipeline Analysis Package Ii, Sai K. Vedantam

Theses

This work describes the implementation of arithmetic pipeline scheduling algorithms, to enhance an existing simulation package. The user need only specify the arithmetic equations to be processed and the required stage configuration. The program automatically performs the tasks of forming the reservation table, building the pipeline and specifying the input/output connectivity for each segment and multiplexer in the pipeline. This package integrates two existing simulation tools and enhances many aspects of the previous programs.

The main application area for such a tool is education. Since it is very easy to use and requires little or no time for one to …

Distributed Data Collection System Based On Hierarchical Network, Harish Mahindrakar

Theses

On line data collection systems are essential in order to satisfy the requirements for real-time applications. Typical applications are computer integrated manufacturing, security control, hourly wage calculations, human resources management. On line data collection system makes it possible to closely monitor and track different operations with more accuracy. On line data collection systems eliminate redundant work, save time and money.

If the distributed system is based on a multicontroller, it becomes really cost effective solution to build such a system.

This effort is the design of a distributed multicontroller system, required in a data collection system. A hierarchical network is …

Nonlinear, Metal-Clad Optical Waveguide, Bhavesh Patel

Theses

Planar optical waveguides consisting of different types of films including nonlinear films with metal cladding have been studied theoretically. Ideal metal cladding with σ = ∞ and nonideal metal cladding with σ ≠ ∞, that is, with complex refractive index is considered to get electric field and wave number for TE₀ mode. For nonlinear material, approximate solution is derived in a series form using Rayleigh-Schrodinger method. The appropriate eigenvalue equations are solved by Newton-Raphson iteration method. For self-focusing media in the center, the propagation constant increases with increasing power and with self-focusing media in the cladding the propagation constant …

Reduced Complexity Receivers For Trellis Coded Modulations Via Punctured Trellis Codes, Bonchul Koo

Theses

We introduce a new concept, called matched punctured trellis encoding, that simplifies the complexity of Maximum Likelihood Sequence Estimation (MLSE) receivers for combined trellis encoding and modulations with memory. Matched punctured trellis encoding is applied to tamed frequency modulation (TFM) which is a bandwidth efficient correlative - FM scheme. TFM finds applications in satellite, microwave radio, and mobile communications.

Our approach is based on puncturing a rate - 1/2 matched convolutional code to obtain a rate - 2/3 mismatched code. A matched code is one that produces trellis coded modulations of minimum complexity. Puncturing these codes to obtain mismatched codes …

Trellis Coded Partial-Response Channels, Kumari Yalamanchili

Theses

Binary partial-response channels with transfer functions (1+D), (1-D) and (1 — D²) are intersymbol-interference channels which find applications in baseband data communications and magnetic recording systems (tapes, discs, compact discs, etc.). In this thesis we develop a coding technique for improving the reliability of digital transmission over noisy partial-response channels with the above transfer functions. We do so by introducing a new concept, called matched encoding, which arises in the context of trellis coding for channels with memory.

We use inner and outer trellis coding of the partial-response channels. The inner codes called matched inner coset codes, are …

Performance Enhancement & Fault Detection Of Cmos Dynamic Logic For Vlsi, Ashok Arunachalum

Theses

New CMOS dynamic latches are designed which can be used along with conventional dynamic circuits to realize fast pipelined dynamic logic. Also a new method is described for detecting the difficult CMOS Non-classical faults viz. stuck open and stuck on faults. The conventional Domino logic is redesigned to make all the stuck open and stuck on faults detectable.

Transverse Electric (Te) And Transverse Magnetic (Tm) Mode Conversion In Optically Active (Chiral) Embedded Polymeric Waveguides, Mingdeh Chien

Theses

Wave propagation in an optically active isotropic, polymeric thin film waveguides is studied. The waveguides are fabricated using the dipping method. Thin film layers are composed of a passive PMMA (poly methyl methacrylate) host material and a chiral, optically active, ((s)-(+)-1,1'-Binaphthyl-2,2'-dily hydro phosphate), guest material. Experimental results show about 1° per centimeter rotation of polarization as light propagates through a 1.8cm waveguide. The theoretical analysis of the mode structure and wave propagation in the waveguide are examined using first order coupled mode theory. TE (-4 TM mode converter is a typical application of this investigation.

Firmware Toolkit For Larynx Synchronous D.S.P., Shih-Chieh Su

Theses

During the past ten years, digital signal processing has been an extremely active and dynamic field. Advances in integrated circuit technology and in processor architecture have greatly enlarged the scope of the technical areas to which digital signal processing techniques can be applied. Research in fundamental signal processing techniques and algorithms has led to dramatic improvements in the efficiency of signal processing systems.

This thesis creates a fast and cheap DSP package for 8052AH-BASIC. This is a useful and potential package when we apply research in speech science and medical diagnostics. It exploits the latest software-in-silicon technology to create a …

Maximum Rate Of Change Of The Differential Reflection Phase Shift With Respect To The Angle Of Incidence For Light Reflection At The Surface Of An Absorbing Medium, R. M.A. Azzam, A. M. El-Saba

Electrical Engineering Faculty Publications

The differential reflection phase shift, Δ = δ_p - δ_s, associated with the external reflection of monochromatic light at the surface of an absorbing medium is a monotonically decreasing function of the angle of incidence ø which is determined by the complex dielectric function ε. A new special angle of incidence, denoted by ø_Δ′max, is defined at which the slope Δ′ = ∂Δ/∂ø of the Δ-ø curve is maximum negative, Δ′_max, and a transcendental equation is derived that determines this angle. ø_Δ′max differs from the principal angle ø_p at which Δ …

A Microcomputer Based Non-Invasive Cardiopulmonary Monitor Using A Microwave Interferometer, Tanmoy K. Basu

Theses

With a microwave interferometer the vibrational velocity of the anterior (front), as well as posterior (back) chest wall can be monitored and recorded. The recorded signals are a reflection of the mechanical cardiac activity within the chest cavity, as opposed to Electrocardiogram (ECG) which is a reflection of the electrical cardiac activity. The interferometer recordings are obtained with no physical contact between the instrument and the subject. Moreover, the subject can be fully clothed since microwave energy readily passes through normal dry clothing.

A microwave interferometer that is capable of detecting the vibrational velocity of the surfaces of the chest …

Generation Of Atomic Nitrogen By Gas Discharge In Microwave Cavity, Jong-Shun Shieh

Theses

A microwave discharge system for producing atomic nitrogen at low flow rate and low pressure has been investigated. The molecular nitrogen passes through a microwave cavity in a quartz tube and is dissociated by the microwave energy. Subsequent recombination of nitrogen atoms produces a characteristic yellow glow due to the relaxation of excited molecular nitrogen to its ground state. The titration of nitric oxide with atomic nitrogen was used to measure the atomic nitrogen yield. At a 2 sccm nitrogen flow rate the atomic nitrogen yield was 8.75*10¹⁵ atom/sec, which corresponds to a nitrogen generation efficiency of about 1%. …

A Wideband Continuous Phase Shifter For Ka-Band, William J. Tanis

Theses

The design, fabrication and test of a 45 degree microstrip phase shifter capable of full Ka-band performance is presented. The design uses a Lange coupler with two ports terminated with beam-lead varactor diodes to provide continuous phase shift. Although this concept has been employed at X-band and below, this thesis demonstrates its feasibility for wideband use at frequencies as high as 40 GHz. The design uses thin-film capacitors, beam-lead diodes, simulated grounds, and air bridges to achieve a planar geometry and to simplify the production process. Detailed test results using various test circuits are shown for comparison to actual phase …

X.25 Interface Packet Level Simulation, Arvind Tewari

Theses

An X.25 interface was simulated at the packet level and data packets successfully transmitted from the Data Circuit-Terminating Equipment (a process) to the Data Terminal Equipment (another process). This was executed interactively. Two independent processesg were generated on the AT&T 3B15 computer and inter-process communication (IPC) used to transfer the data. The X.25 interface is based on the Open System Interconnection (OSI) model of the International Standards Organization.

Design Of A Lan Based Data Acquisition System For Sensor Applications, Krishna Murthy Uppunda

Theses

This thesis presents the design of a local area network (LAN) based data acquisition system for sensor applications. The circuit designed forms the robotic LAN (RLAN) interface between the sensor IC nodes and the ARCNET network. The RLAN network uses two packet protocols. The sensor data request (SDR) packet is received by the sensor IC nodes and the sensor transmits the sensor data (SD) packet. The RLAN interface provides a two way communication between the sensors and the ARCNET network. Whenever an ARCNET node receives the SDR packet, it stores the packet temporarily in a 1k RAM buffer. The RLAN …

Use Of The Lms Algorithm In Ecg Analysis, Xiaohua Yang

Theses

The purpose of this thesis is to develop an IBM PC-AT based system to effectively process electrocardiogram (ECG) signals. Adaptive filter theory is used to implement a noise cancellation system (adaptive noise canceller), which adaptively cancels the ECG signals resulting in real ECG noise. The adaptive process is based on the well known least-mean square (LMS) algorithm.

The noise canceling system is software based. Several programs have been written, which include analog to digital converter control, data acquisition and storage, data retrieval, adaptive filtering and digitized data graphics.

The thesis presents numerous computer experiments. The performance of the adaptive noise …

Design Of A Temperature Sensor For Gallium Arsenide Ic Applications, Raviprakash Raviprakash Gutala

Theses

This thesis presents the design of a temperature sensor circuit including sensor, differential amplifier, and a memory element for gallium arsenide IC standard cell applications. A standard 1-um depletion-mode GaAs MESFET technology has been used for the design of the circuit. The circuit is intended to be used as a standard cell in GaAs les providing an alarm when the sensor temperature reaches 125 °C. The circuit includes a NAND latch which is set when the chip cell temperature reaches 125 °C. The output of the latch can be sensed by additional circuits (on or off the GaAs chip) which …

Progressive Transmission Of Images Using Pyramidal Structure, Chin-Hua Hsu

Theses

A progressive image transmission scheme based upon Laplacian pyramid structure is used for image coding over low-bandwidth channels. The filtering and differential pulse code modulation (DPCM) methods of image coding are generalized to allow quantization of the Laplacian images. Filtering is performed with a local, symmetric weighting function. The three different quantizers, (1) scalar quantizer, (2) memoryless vector quantizer (VQ), and (3) finite state vector quantizer (FSVQ), are used here to compare the results. In the receiver end, the image can be reconstructed using reverse procedure. The reconstructed image is not the same as the original image because of the …

Microprocessor-Based Processing Unit Implemented By Xilinx Programmable Logic Array, Lee Chuan Hu

Theses

The 8052 microprocessor-based processing unit is a super single board computer with many unusual features: memory page selecting with page indicators, on-board EPROM/PROM programmer, real time clock, battery back-up RAM, and memory mapped I/O. It is implemented by using Xilinx programmable logic array and can be used for various instruments. Xilinx user-programmable Application-Specific Integrated Circuit (ASIC) is a large logic array with up to 9000 equivalent gates. The advantages of programmable logic devices over standard ICs are more flexibility, design security, lower cost, higher performance, reduced power consumption, smaller size, and increased reliability. The system development time is also greatly …

Reliability Problems And Failure Mechanisms In Ic Packaging, Dilip J. Patel

Theses

Today, reliability is acknowledged as an important item in design and operation of electronics circuits and system.

This thesis provides information on evaluation of the reliability for hermetic and non hermetic IC packages made by different manufacturers.

Literature study concentrates on the reliability and related problems in IC packages developed between 1970 and 1988.

Several failure mechanisms and failure modes are discussed to point out how higher reliability in IC packages may be achieved.

The bibliography is given in a chronological order to help further research in this area.

A Methodology For Designing Spacecraft Onboard Processing Systems, Mohammad Nadeem Ahmad

Theses

A three layer methodology is presented for designing spacecraft onboard computer systems. The system design is perceived as a sequence of three hierarchical layers: the Dedicated Processing Layer, the Application and Support Processing Layer, and the Communications Processing Layer. Each layer implements a distinct set of functions and offers services at different levels of abstraction. As opposed to the ISO/OSI Reference Model, where the prime objective is to implement peripheral interaction between two systems, the layered approach used here is to address the problems in system design itself. The problem is approached in a bottom-up fashion, starting with the description …

A Cmos Digital Temperature Sensor For Asic Vlsi Standard Cell Design, Chih-Ta Sung

Theses

This thesis describes the design of a CMOS digital temperature sensor cell including the physical layout database.This cell is designed for implementation within an ASIC VLSI chip as a standard cell . The digital temperature sensor can trigger an alarm signal and turn off power for preventing fatal damage in the VLSI chip if overheating occurs.A digital output also permits measurement of temperature over the 0 - 120°C range with ±3.4°C accuracy using standard VLSI foundry processing. Two sensing elements are implemented in a differential mode within the temperature sensor cell. An operational amplifier is used in the successive approximation …

Computer-Controlled Programmable Pulse Generator For A Jeol Jnm-Ft-1a Radio Frequency Amplifier Section Of A Nuclear Magnetic Resonance Spectrometer, William H. Russell, Roger M. Hawk

Journal of the Arkansas Academy of Science

A microprocessor controlled programmable pulse generator was specifically designed to interface with the JEOL JNM-FT-1 A Radio Frequency (RF) section of a nuclear magnetic resonance (NMR) spectrometer. The programmable pulse generator was programmed and controlled by an IBM compatible computer. Statis rams were utilized as the programmable pulse generator's on board memory which were used to store the pulse sequences. Pulse widths can be programmed from 0.2 microseconds to 14.3 minutes. The JEOL RF section is unique in that it allows the pulse generator to control the phase of the RF transmitted to the NMR probe and whether the sample …

Lf Pulse Magnetic Field Generation And Uniformity Studies, Shun-Wen Tan

Theses

This thesis dealt with the design and construction of a pulsed magnetic field (PMF) generation circuit. The spatial variations of the generated PMF are also studied The generated PMF is intended to be used for two purposes (a) in hospitals, for its healing effect of broken bones, and (b) to study the effects of PMF on industrial bacteria and their activity in transforming toxic waste to benign waste

A square coil made of two sections is constructed and the associated circuitry for the PMF generation is designed and built The circuitry is divided into two parts. the control circuit and …

An Application Of Bit Level Systolic Arrays On Digitized Adaptive Array Processes, Shin-Hwa Tsai

Theses

This thesis has concentrated on some aspects of adaptive arrays, i.e., the data type as well as the calculating processes under an optimized version. An adaption of a modified bit-level array is described on the control structure for processes like correlation matrix, Q-R decomposition and solution of triangular linear systems. In short, an implementation of SMI(Sample Matrix Inversion) under a parallel systolic array process is consider5ed. Also an application of utilizing systolic array on a matrix inversion is derived. As a result, it could be predicted that a VLSI chip implementation for small adaptive arrays is feasible in the near …

Netexpert, An Expert System For Computer Network Management, Sailen Patel

Theses

Data Communications systems consist of distributed software and hardware components executing concurrently a number of communications functions. The logical framework for these functions is called data communication architecture and is layered hierarchically according to the OSI model. The protocol defines the syntax and semantics of the communications between entities of the same layer. NETEXPERT: An Expert system described here contains a set of formal specifications corresponding to different abstractions level of the protocol. On the highest level there is a specification of the service provided by this protocol. On the consecutive lower levels there are successive refinements of this specification …