Electrical and Electronics Commons^™

Artificial Dielectric Polymeric Optical Waveguides, Peng Chen

Theses

Wave propagation in artificial dielectric polymeric optical thin film waveguides is studied. These artificial dielectric films are made of multiple layers either metallic or semiconductor clusters in polymeric matrix. The waveguides are fabricated using the plasma polymerization and vacuumm evaporation deposition method. By analyzing results of these kinds of structures, some important conclusions can be obtained. The artificial dielectric layer in the waveguide center effectively changes the modal distribution in the waveguides. In the case of semiconductor layer, an all optical switch may be realized.

A Multimode Index Detecting Sensor For Use In Plastic Concrete, Qiyu Chen

Theses

This thesis describes a microcomputer-based measuring system using a laser diode source, a fiber optic sensor and a microcomputer DMA interface to test and analyze the entrained percentage of air in concrete.

The principle of refraction and reflection of light in optical fibers is applied to detection of air bubbles. Reflected light intensity signals are detected and transferred through a DMA interface to a laptop computer. Analysis of reflected light intensity produces a measurement of the air content of fresh concrete. Accuracy of the system is evaluated through extensive laboratory and field trials.

Ct Fan Beam Reconstruction With A Non-Stationary Axis-Of-Rotation, Joseph A. Concepcion

Theses

One important aspect for reconstructing an image using Computed Tomography (CT) is that the axis-of-rotation must pivot at the same point on the reconstruction plane as the x-ray source and CT scanner assembly rotates around the imaged object. This pivot point is used as a reference point for backprojecting pixel values to their proper coordinates. Therefore, reconstructing an image with a non-stationary axis-of-rotation would backproject pixel values to wrong coordinate points, since the reference point is non-stationary for every projection angle.

A convolution filtered backprojection algorithm has been derived for correcting images that were acquired with a non-stationary axis-of-rotation using …

Tri-Color Led Display System Using Microcontroller, Costakis A. Constantinou

Theses

A seven-by-forty-eight tricolor LED display panel is designed and built around the 68HC11 MCU.

Four bilateral switching transistors (4066) are used in a Wien bridge configuration to drive each tri-color LED. With this circuitry one is able to drive the tricolor LED symmetrically. An alternative design that uses only two switching transistors is also offered.

A software program was developed to output on the display scrolling and fixed messages. Each message could be displayed in a different color (Red, Green and Yellow) and at a different speed (Slow, Fast, and Medium). The program also includes an editor with insertion and …

Novel Way Of Sub-Carrier Coherent Detection And Clock Recovery In Fiber-Optic Communications, Narayan Gehlot

Theses

We experimentally demonstrate a novel concept for recovery of a Sub-Carrier and Timing Clock in fiber-optic communication systems using a Wavelength Division Multiplexing technique. The idea is to send a low radio frequency (RF) as a reference pilot from the transmitter to the receiver on a separate laser using the principle of Wavelength Division Multiplexing (WDM). This low frequency signal is taken to be a subharmonic of the subcarrier used to carry information and intensity modulate another laser. Such approach will be expected to generate at the receiver a local oscillator in high coherence with the subcarrier.

We show that …

On The Estimation Of New Life Model Of Transformer Insulation Material Under Combined Electrical And Thermal Stress, Chiming Lin

Theses

Results of combined electrical and thermal aging and only thermal aging studies conducted on a 'fish' paper insulation material are presented in this thesis.

The model for aging has been proposed which is essentially the Arrhenius equation with a weighted factor {exp -cg/kT1 to describe the enhanced reaction rate process under combined thermal and electrical stress. A procedure has been described for evaluation of parameters of this new model.

It is seen that life estimates obtained with this model are close enough to the experimental results.

In addition, reliability data were also generated on the same material using electrical noise. …

Hot : A Timing Optimizer For Hierarchical Vlsi Circuits Using The Charge Conservation Delay Model, Yumei Quan

Theses

The primary benefits of VLSI chips are their high speed, small area, and lower power. These performance attributes are dependent on the quality of chip design. As a result, performance can be optimized by proper design decisions. One of the decisions in chip design is the selection of gate delays and/or transistor sizes (channel width of an MOS transistor).

To optimize the performance of VLSI chips, transistor delay models and optimization algorithms are very important since accurate analytical models for signal delay are essential to replace expensive device level simulation and the high efficient algorithms assist designers in developing high …

Comparative Study Of Prediction Gain Based On Neural Network Architecture, Prashant M. Shah

Theses

This thesis describes the Neural Network approach to design predictor using Delta and Generalized Delta Rule. The predictor is designed by supervised training based on the typical sequence of pixel values. Neural Network is used to find the coefficients of the predictor. Both 1-D and 2-D scheme of the pixels as well as linear and non-linear correlations are used to find the coefficients by training. Different combinations of pixels are used to find the "best" combination among the order of the predictor.

Efficient Multiprocessor Scheduling By Mean Field Theory Neural Networks, Pei-Ken Yi

Theses

In this thesis, we develop an optimization method based on Mean Field Theory (MFT) Neural Networks to solve the Task Scheduling problem. The MFT algorithm combines characteristics of the Simulated Annealing (SA) algorithm and the Hopfield neural network. MFT exhibits rapid convergence and at the same time it preserves the solution quality afforded by SA. Since MFT has been successfully used to solve the Traveling Salesman Problem (TSP), a new modification to MFT is also presented which supports Task Scheduling problem. The temperature behavior of MFT during Task Scheduling is approximately analyzed and shown to possess a critical temperature (71,) …

Integrated Digital Speech System With Pc, Zhen Zhu

Theses

A PC-based real-time digital speech processing system is designed. Speech synthesis, analysis, storage and retrieval are implemented in the system with intelligent telephone functions. Speech data are stored on floppy disk and easy to retrieve. Though floppy disk is slow in speed, real-time processing is achieved with low bit rate coding. The computer gets speech data from a digital speech processing unit or send data to it through a synchronous seiial communication port. The analog input of digital speech processing unit can be selected from the telephone line or the microphone, and output of the digital speech processing unit can …

Uniformity Correction For Infrared Ir-Ccd Camera, Chien-Ming Leng

Theses

This thesis describes the results of a study of three types of uniformity correction schemes for an infrared camera. More specifically, a Datacube Image System was used to simulate the three uniformity correction schemes for a 320x244-element IR-CCD TV camera with PtSi Schottky-barrier detectors. The three uniformity correction schemes are: one-point uniformity correction with single background, one-point uniformity correction with multibackground and two-point uniformity correction. Datacube programs were developed for the three above uniformity correction schemes and some experimental results were obtained.

The Bandwidth Allocation Of Atm Through Genetic Algorithm, Hong Pan

Theses

In this thesis, we develop an optimization method based on Genetic Algorithm to achieve the bandwidth allocation of ATM network. In Broadband Integrated Service Digital Network (BISDN), the Asynchronous Transfer Model (ATM) is already adopted as the transfer standard by CCITT. ATM is a high-bandwidth, low-delay, fast-packet switching and multiplexing technique. Using ATM technique, we can flexibly reconfigure the network and reassign the bandwidth to meet the requirement of all types of services. As an effective optimization method, Genetic Algorithm(GA) is applied to implement the bandwidth allocation of ATM. GA is a class of search algorithm based on the mechanics …

Dual Token Ring Lan Performance, Pratap S. Pasupuleti

Theses

A simulation model to analyze the performance of a dual token ring LAN is developed. The performance measures throughput, average packet delay and maximum delay per packet are obtained. System performance is analyzed for different loads, number of stations, and packet lengths. The performances of token ring LANs with a conventional structure and a dual ring structure are compared for both uniform packet sizes and a case with mixed packet sizes. In the uniform packet size case, the dual ring delays were lower at equivalent throughput because of propagation delay effects. In the mixed packet size case the maximum delays …

Design, Fabrication, And Testing Of Temperature Compensated Magfet, Dilip K. Sampath

Theses

A simple model based on dc behaviour of MOS transistors operating in weak inversion is derived on the basis of previous publications. The bipolar like source to drain transfer characteristics of MOS transistor in weak inversion was used to implement a voltage source that is proportional to absolute temperature (PTAT); a cell that can be stacked to obtain the desired voltage. A CMOS temperature compensated current reference is implemented using PTAT cell with MOSFET as current defining element. A CMOS magnetic field sensor has been developed. The sensitivity of sensor is dependant on the bias current; incorporation of temperature independent …

An Efficient Annealing Algorithm For Global Optimization In Boltzmann Machines, Rajendra Sarasakrishna

Theses

This thesis proposes a new annealing algorithm for Boltzmann Machines. This algorithm uses an Exponential Formula for temperature scheduling that produces remarkably better solutions for global optimization. The superiority of the new algorithm is shown by computer simulations of several examples on Boltzmann Machine and its variants. This is also shown to have better properties than algorithms like Generalized Simulated Annealing which possess somewhat similar dynamics.

Fault Tolerant Clos Network, Preet Mohan S. Ahluwalia

Theses

Multistage interconnection networks, or MINs, provide paths between functional modules in multiprocessor systems. The MINs are usually segmented into several stages. Each stage connects inputs to appropriate links of the next stage so that the cumulative effect of all the stages satisfies input-output connection requirements.

This thesis deals with a fault tolerant Clos network. The fault tolerance technique involves addition of extra switches per stage to compensate for any switch failure The reliability analysis of both ordinary and fault tolerant Clos networks is presented. The optimal number of extra switches required to get the best reliability results has been analyzed.

Fast Packet Switching For B-Isdn With Neural Net Control, Ajit K. Chaudhuri

Theses

The concept of integrated network where both the voice packet and data packet are delt with, started taking shape since 1970. Later, Users? demand for communication of data, voice, file, facsimile, image, videotext, videophone, videomovie has also been felt. All these services need bit rate of transmission in the order of 10, even 100 Mbits. An economical way to transmit this higher bit rate, with flexibility of bandwidth, is to treat voice/video in the form of packets and transmit those packets in real time. Studies of this kind of communication is carried out in Broadband ISDN ( BISDN). At this …

N-Cross Coupled Phase Locked Loops, Joseph C. Aboukhalil

Theses

Interference cancelation has been mainly performed using arrays, in an important issue in communication both array and spatial cancelation and time domain approach were used. In array applications, depth of cancelation may dependent on the interferences to background power ratio and their spatial distributions. Also, array cancelers are inadequate when the signals are less than an array beamwidth apart. The latter was dealt with using supperesolution and eigenanalysis methods. Different time domain methods were used in the past. Among them what is termed Cross-Coupled PEL. It is an arrangement of two PLL each one is locked on and tracking one …

Electromagnetic Transients Program Interfacing, Enhancement And Comparison With Spice, Siswa Trihadi

Theses

The Electromagnetic Transients Program (EMTP) is a computer program used to simulate high speed power system transients. The EMTP input data structures and the rules in setting up the input data file are described in this thesis by means of two sample cases i.e an RLC series circuit and a sin le line to ground fault in power system.

The EMTP input data are very detailed an highly-structured column-dependent. To improve the user-friendliness of EMTP by ignoring the difficulty of arranging the column structures, this thesis presents the EM P User Interactive Program. Sample cases using this interactive program are …

Estimating 3-D Motion And Structure Parameters Of A Rigid Planar Object By Establishing Landmark Correspondences, Herman Agustiawan

Theses

The application of a landmark based approach in recognizing 3-D rigid planar objects[3] along with two different motion and structure estimation algorithm [21][23] have been studied to perform motion and structure estimation tasks of moving objects. The recognition algorithm is based on a sphericity value derived from affine transformation that maps feature points in the object under observation from first to second view in the 2-D image space. The motion and structure estimation algorithm is based on a unique mapping given four or more feature point correspondences.

More than ten experiments have been done including small and large rigid motions. …

Performance Evaluation Of Extended Token Ring Network Under Message Priorities, Prakash B. Kukadia

Theses

Local Area Networks carrying multiple priority classes of messages have received considerable attention recently. A simulation model of a symmetric, priority based network, consisting of token ring networks interconnected by a bridge is implemented. Messages are divided into two priority classes, namely, high priority classes and low priority classes. Two different approaches are considered for transmission of high priority messages. [1] Each station transmits the same amount of high priority traffic when the token reaches the station, regardless of the time elapsed from previous token arrival. [2] The amount of high priority traffic transmitted by each station may vary at …

Study And Characterization Of Ingaas Photodiode And Photodiode Arrays, Krishna R. Linga

Theses

This thesis describes the InGaAs p-i-n photodiodes, photodiode arrays and their characterization. A work station was also built for the opto-electrical characterization. The main feature of the In,_zGa_iAs photodiodes with x > 0.53 is its response to higher wavelengths than the standard lattice-matched photodiodes. An In_xGa_1-xAs photodiode with x = 0.88 respond to 2.6 μm wavelength. The application of these photodiodes is forlIber optic communications, spectroscopy and instrumentation. A complete characterization and analysis of the In_0.88Ga_0.12As photodiodes is presented. Dark current analysis, which is a critical parameter in photodiodes, …

Adaptive Stack Filtering By Lms And Perceptron Learning, Yu-Chou Huang

Theses

Stack filters are a class of sliding?window nonlinear digital filters that possess the weak superposition property(threshold decomposition) and the ordering property known as the stacking property. They have been demonstrated to be robust in suppressing noise. Two methods are introduced in this thesis to adaptively configure a stack filter. One is by employing the Least Mean Square(LMS) algorithm and the other is based on Perceptron learning.

Experimental results are presented to demonstrate the effectiveness of our methods to noise suppression.

Recovering Surface Structure Using Direct Method, Zhu Ying

Theses

A new approach to recovering surface structure from a pair of stereo images is proposed in this thesis. The approach is based on an extension of the concept of optical flow to a spatial sequence of images. z.e., the unified optical field (DOFF). A direct method in spatial domain is developed which is able to recover surface structure that can be characterized by an Nth order polynomial equation. The order N of the surface can be one. a planar surface. or two, a cylindrical or spherical surface. for example. or any number higher than two. This is a big improvement …

An Investigation Of Optoelectronic Integrated Circuit Receiver, Dinar S. Gupte

Theses

This thesis report presents an investigation of an OptoElectronic Integrated receiver Circuit (OEIC). An OEIC on Silicon (Si) substrate is analyzed and simulated as part of this investigation. The OEIC is based on GaAs technology. The advantages of this are its compactness, high speed, low noise and high reliability in light wave communication systems. A higher output signal is required to make such devices suitable for practical applications. This is achieved by the use of a cascode stage. The fabrication techniques of the relevant semiconductor devices have also been discussed.

In light wave communication systems, the region of minimum losses …

Design And Development Of Ccd Camera For Document Scanner Using Optical Fiber Bundle, Aniruddha P. Joshi

Theses

A CCD camera for the gray scale document line scanner has been designed and developed at Photon Imaging Corp. The scanner consists of a revolutionary optical fiber bundle, CCD camera, and control electronics. The key concept resides in the fiber-optic bundle. At one end it has a linear array of equally spaced light guides. These terminate at the opposite end in a square array with a polished surface for viewing by a camera. The fan-out from linear to square end is not done with attention to ordering, so the bundle may be relatively inexpensive. Reordering is done electronically using an …

Analysis Of Field Distribution Of A Dielectric Resonator And Its Applications, Manohar R. Kamath

Theses

Dielectric resonators (DR) are suitably shaped objects made of high dielectric constant materials like TiO₂, BaO, ZnO, and accessory ingredients, which can function as electrical resonators covering a very wide frequency range upto 40GHz. The physical dimensions of dielectric resonators are in mm range. High dielectric constant material resonators seem to be ideally suited for microwave applications because of their miniature size, low loss, insensitivity to magnetic dc biasing fields, and ability to concentrate large RF magnetic fields in small volumes. However temperature stabilization of dielectric resonators is an important consideration as the center frequency is a function …

Slotted Aloha Protocol For Packet Transmission Via Satellite Link : Throughput Performance Of Continuous Transmission Packet, Solon Karashialis

Theses

The throughput performance of multi-access schemes for data traffic through a satellite channel is analyzed in this paper. Three general schemes are described: channel reservation schemes, random access schemes, and padket reservation schemes. This thesis considers only the random access schemes. Analysis and comparison between ALOHA and Slotted ALOHA are made, but the main emphasis is on satellite channel throughput. A continuous transmission protocol for Slotted ALOHA is suggested in which each ground earth station repeats the transmission of each packet in a number of random repetition slots. The channel is idle when no ground station (GS) is transmitting on …

An Integrated Circuit X-Ray Sensing Array Based On A Cmos Flip-Flop Cell, Huan-Chung Lee

Theses

A novel X-ray sensor IC has beeli designed which counts individual photons at rates up to 5,000,000 counts per second. A two-dimensional X-ray flip-flop sensor array, consisting of an 30 x 30 matrix of CMOS flip-flop sensors integrated in one chip together with an internal clock generator and access selection circuitry is described. A flip-flop sensing cell contains cross-coupled CMOS devices, one of which is connected to a large-area reverse-biased diode. A large area diode exposed to X-ray flux triggers the flip-flop. By reading out the final stable state of the flip-flop, the absence or presence of an X-ray photon …

Optimization On Isdn In Multihop Radio Networks Through Genetic Algorithm, Prashant H. Pahade

Theses

Integrated service of voice and data on a single network has received considerable attention recently. Various techniques have been proposed and analysed for multiplexing voice and data over a large bandwidth channel. Efficient channel allocation for voice and data on multihop radio network 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 Genetic Algorithm. Computer Simulation shows that this leads to the decision which is beneficial to the services of both voice and data in the network.