Engineering Commons^™

Neural Net Classification Of States In Finite State Vector Quantization, Zhigang Zhang

Theses

In this thesis, a new image coding technique based on Neural Network Finite State Vector Quantization(NNFSVQ) is presented. The new design takes advantage of the high interblock spatial correlation of pixels in typical grey-level images, in addition to intrablock correlation already exploited by vector quantization (VQ). Although many FSVQ require large memory space for the storage of the numerous state codebooks, the memory space requirement of NNFSVQ can be reduced by a very large factor (about 10²-10³) to manageable size without impairing image quality. Simulation experiments have shown that by using NNFSVQ the bit rate can …

Optimization Of Bandwidth Allocation In Atm Nets Through Simulated Annealing, Chien-Long Hou

Theses

Optimization of Bandwidth Allocation in ATM network is considered in this thesis. We address the problem of determining optimal bandwidth allocation in such BISDN's that adopt ATM as their basic switching. technique by using Simulated Annealing. Computer simulation shows that this optimal policy leads to the configuration which yields the minimum average packet delay.

Landmark-Based Shape Recognition By A Modified Hopfield Neural Network, Kuowei Li

Theses

In this thesis, we introduce a new thethod to achieve partial shape recognition by means of a modified Hopfield neural network. To recognize partially visible object, we represent each object by a set of "landmarks." The landmarks of an object are points of interest relative to the object that have important shape attributes. Given a scene consisting of partially occluded objects, a model object in the scene is hypothesized by matching the landmarks of the model with those in the scene. A measure of similarity between two landmarks, one from a model and the other from the scene, is needed …

A Novel Schottky Barrier Mosfet For Vlsi Applications, Venkata S. Simhadri

Theses

Schottky barrier MOSFETs are expected to offer certain fabrication advantages, low series resistance and the feasibility to go into sub-micron technology without having short-channel effects. A p-channel MOSFET using Schottky contacts as source and drain is reviewed theoritically. The limitations of the device arising from the oxide offset between source/channel is studied with the help of one dimensional simulation SEDAN. The process sequence leads to an offset between source and channel. The performance of the SBMOSFETs with and without offset is estimated using two dimensional device simulation program PISCES-II for PtSi and IrSi as source and drain material. A novel …

Ligament Reconstruction : A Biomechanical Cadaveric Test Of Autogenous Repairs And The In Vivo Evaluation Of Synthetic Scaffold Materials, Anne Marie Daly

Theses

The knee joint is the largest and one of the most complex joints in the human body. The anterior cruciate ligament (ACL) is one of the major intra-articular ligaments responsible for controlling and guiding the knee through most of its range of motion and its rupture alters normal joint mechanics.

One objective of this thesis was to determine if two autogenous tissue ACL reconstruction methods were biomechanically equivalent. The first method using the central one-third of the patellar tendon has been used clinically since the early 1960s. The second method utilizes portions of both the semitendinosus and the iliotibial band. …

Design Of A Microengineered Pressure Sensor, Ranjeet Alexis

Theses

A new family of microengineered vacuum ionization gauges of an approximate volume of 200µ³ has been designed. These devices can he fabricated using existing semiconductor processing capabilities. The focus of this thesis is to scale down the current state-of-the-art for ionization sensors to micron dimensions. These gauges can be manufactured economically and potentially will be integrated with more complex structures and circuitry. In these devices an active ionization volume of micron dimensions is used for launching ions in a trajectory towards a collection electrode. Ionization of gas species is accomplished by an electron flux of sufficient energy. Analysis of …

Point Pattern Matching By A Genetic Algroithm, Minghwang Chen

Theses

The problem we consider is to find a subset of points in a pattern that best match to a subset of points in another pattern through a transformation in a least squares sense. Exhaustive search to find the best assignment mapping one set of points to another set is, if the number of points that are to be matched is large, computationally expensive. We develop a genetic algorithm which searches for the best ("almost the best") assignment efficiently. To map the point pattern matching into the framework of a genetic algorithm, we use a fitness function which inversely proportional to …

A Critical Analysis On Cogeneration Policy, R. Tjahjokartiko Gondokusumo

Theses

It could be difficult to understand electricity problems without knowing its history; how a combine of legal, administration, and financial means effects electricity in the development. The recent public law on energy-related issues traceable by this study is the Renewable Energy and Energy Efficiency Technology Competitiveness Act of 1989.

In short, cogeneration was proposed to utility (as public property) from industry (as private property) under PURPA (of which National Energy Act is the legislative history). Thus, it should be clear that the problems of cogeneration is not pro or contra issues. It is a national issue. Then, a cogeneration planner …

Decomposing Non-Product Form Queuing Lattices Through Genetic Algorithm, Wei Han

Theses

In this paper, a Genetic Algorithm technique is adapted to decompose the state transition lattice of a class of non-product form queueing models. Genetic Algorithms are search algorithms based upon the mechanics of natural genetics. They combine a survival-of-the-fittest among string structures with a structured, yet randomized, information exchange to form a search algorithm with some of the innovative flair of human search. While randomized, genetic algorithms are no simple random walk. They efficiently exploit historical information to speculate on new search points with improved performance. Here genetic algorithms is applied to a non-product queueing lattices optimization problem. Only the …

Performance Evaluation Of Consumer Electronic Bus, Sairaj R. Pakkam

Theses

This thesis describes the performance evaluation of the Consumer Electronic Bus proposed by the Electronic Industries Association. To study the behaviour of CEBUS under different traffic conditions, a simulation program was developed modelling the layer architecture of CEBUS. The CEBUS is based on the ISO/OSI model of layered architecture. The simulation results have shown that, when the throughput of the network is small, the delay is bounded for all messages of all priorities. As the throughput of the network increases, under the presence of more high priority messages, the lower priority messages get queued at their nodes. It is also …

Improving The Throughput Of Plasticating Extruders : Measurement Of The Interparticulate Friction Coefficient For Polymeric Particulates With Circular And Profiled Cross Sections, Aiping Chen

Theses

This thesis deals with the coefficient of friction between individual polymeric pellets, the interparticulate friction coefficient (IPFC). It has been measured using a shear cell for a wide variety of circular and profiled cross?section pellets for a variery of polymeric materials. First, the thesis explains the reasons why it is desirable to enhance the IPFC based on the melting mechanisms in a single screw plasticating extruder. By making pellets with profiled cross?section pellets, the IPFC is greater than for pellets of circular cross?section. Second, it describes the test apparatus for measuring the IPFC and the method for calculating the IPFC. …

Hardware Algorithms For Computing Transcendental Functions, Xin-Pei Gong

Theses

The COordinate Rotation Digital Computer(CORDIC) is a special-purpose digital computer for real-time airborne computation. In this computer, a unique computing technique is employed which is especially suitable for solving the trigonometric relationships. A new computing technique based on the CORDIC algorithm is developed to reduce the number of iterations by one half for each input angle. This improvement is accomplished. by scanning multiple bits of the input angle(in our case, two) at a time. The CORDIC equations are rewritten accordingly and a hardware implementation structure is also presented. The results of the software simulation of the new algorithm are as …

Conditional Artificial Dielectric Waveguide, Hsien-Wen Ho

Theses

A thin layer of semiconductor ( the guest material ) is sandwiched between two polymeric films ( the host material ) to form an artificial dielectric waveguide. An artificial dielectric is a composite material consisting of a dielectric with a large number of conducting particles arranged in a three-dimensional pattern. The particle dimensions are smaller than the optical wavelength of interest. A beam of light with a photon energy above the band-gap of the semiconductor ( pump light ) induces electric and magnetic dipoles which affect the propagation of light with a photon energy below the band-gap ( probe light …

Comparative Analysis Of Single And Double Dwell Acquisition Schemes, Gurinder Singh Ahluwalia

Theses

Single and double dwell pseudonoise (PN) acquisition systems are described, explained and analyzed. These systems are designed to synchronize a locally generated PN signal with a received PN signal of unknown phase in the presence of noise. The mean, variance and an approximate probability distribution function (PDF) of the acquisition time for the single and double dwell PN acquisition schemes is developed. Intuitively, the double dwell acquisition system should be superior to the single dwell system because of the ability to quickly dismiss incorrect cells and further verify probable hits. It is shown analytically that this is in fact true …

Improving Solids Conveying In Plasticating Extruders : An Investigation Into Manufacturing Processes And Manufacturing Systems For Profiled Thermoplastic Pellets, Oommen Cherian

Theses

The objective of the thesis is the manufacture of thermoplastic bilobal and trilobal profiled pellets for the determination of the interparticulate co-efficient of friction exhibited by solid beds of such pellets. The enhancement of the interparticulate coefficient of friction is expected to lead to ameliorated solids conveying rates in plasticating extruders.

Predicting the product shape from a profile die is very difficult due to the elastic memory of plastics and the complex boundary conditions. Consequently the cost involved in experimenting with different profile dies is high. Therefore a standard die with several die inserts of varying cross-sections were used to …

Small Disturbance Stability As Affected By Excitation Controls, Alfredo Flores

Theses

The effect of excitation control systems on the power system's small disturbance stability limits has been investigated in this thesis. Three excitation control schemes namely the proportional, fast?acting and the modified fast?acting have been studied.

The stability results were predicted directly in terms of the AVR gain controlling parameters following one?dimensional and two?dimensional frequency domain separation technique. The necessary algorithms and computer simulation programs have been developed.

In case of a modified fast?acting excitation control with three unknown variables, a procedure has been proposed to obtain the stability results by extending the two?dimensional frequency domain separation technique.

Effect Of Moisture On Microcircuit Failure, Chandrabala D. Patel

Theses

Stability and reliability of microcircuit is dependent on its design, fabrication, testing, storage and use.

In this thesis emphasis is given on various failure mechanisms of Integrated Circuits in humid environment and techniques of improving reliability. Other factors which affect the failure of integrated circuits are also discussed. Moisture induced failure modes, semi-reversible failures and irreversible failures (surface leakage current and corrosion-causing interruption of interconnection lines) are also reviewed.

Controlling the contaminants and moisture related corrosion are also covered. The quickest way to evaluate the reliability of microcircuit is by accelerated aging test and by selection of meaningful criteria of …

Damage Effects To Si-Sio2 Structures Due To Reactive Ion Etching, Moshe D. Bunyan

Theses

This thesis presents the damage effects to the Si ? SiO₂ structures due to Reactive Ion Etching (RIE). The research was carried out on Si ? SiO₂ MOS capacitors which were fabricated using RIE and wet etch (Hydrofluoric acid etch (HFE)) Process. The experiment was carried out using CV technique and Ellipsometry. Various electrical parameters were measured from CV *curves of these MOS capacitors. It was observed that the CV curve obtained for the RIE etched sample showed considerable deviation from that of the control sample. This indicates the presence of excess of interface trap charge density which …

A Study Of Signal Cancellation Effects In Adaptive Arrays, Cheng-Der Sun

Theses

An adaptive array can automatically place pattern nulls in directions from which undesired signals (interference, jamming, or clutter, etc.) arrive and can also provide gain for a desired signal. The purpose of this study was to study the effects of the adaptive array on the desired signal while suppressing the undesired signal.

This was done by studying the transfer characteristics of the adaptive array between its input and output. In this study, C.W. jammers along with the desired signal were considered and input and output relationship of the adaptive array were determined. Several basic types of adaptive arrays were studied …

Demulsification And Separation Of Oil In A Water/Particulate System, Fong-Jung Tai

Theses

The wastewater generated from installation factories contains high suspended solids ( SS ) and oil. Effective removal of oil and clay particles in washrack wastewater can be achieved by using organic polymer TFL-398 alone or in conjunction with alum. The dissolved/emulsified oil concentration and suspended solids are used to represent the degree of oil demulsification and clay particles destabilization, respectively.

To improve the efficiency of oil demulsification and reduce the chemical consumption, pretreatment of the influent wastewater is essentially necessary. pH adjustment to 11-12 generally reduces chemical requirement. Total oil concentration was reduced significantly at pH = 11.7 without any …

A Comparative Study Of Edge Detection Techniques, Jaskaran Singh Dhaliwal

Theses

The problem of detecting edges in gray level digital images is considered. A literature survey of the existing methods is presented. Based on the survey, two methods that are well accepted by a majority of investigators are identified. The methods selected are: 1) Laplacian of Gaussian (LoG) operator, and 2) An optimal detector based on maxima in gradient magnitude of a Gaussian-smoothed image. The latter has been proposed by Canny[], and will be referred as Canny's method. The purpose of the thesis is to compare the performance of these popular methods. In order to increase the scope of such comparison, …

A Stereo Vision Technique Based On The Multi-Positioned Camera Criterion, Jie Bao

Theses

A modified feature based stereo vision [sic] technique is described in this thesis. The technique uses the curve-segments as the feature primitives in the matching process. The local characteristics of the curve-segments are extracted by the, Generalized Hough Transform.

A set of images of a scene, which are taken by a multi-positioned camera satisfying the parallelism criterion, are first filtered by the Laplacian of a Gaussian operator in different widths, i.e. coarse to fine channels. At each channel, the Generalized Hough Transform is applied to the curve-segments in each image. The curve position, the curve-length, the curve centroid, the average …

An Artificial Neural Network For Redundant Robot Inverse Kinematics Computation, Wibawa Utama

Theses

A redundant manipulator can be defined as a manipulator that has more degrees of freedom than necessary to determine the position and orientation of the end effector. Such a manipulator has dexterity, flexibility, and the ability to maneuver in presence of obstacles. One important and necessary step in utilizing a redundant robot is to relate the joint coordinates of the manipulator with the position and orientation of the end-effector. This specification is termed as the direct kinematics problem and can be written as x = f(q)
where x is a vector representing the position and orientation of the end-effector, q …

Design And Analysis Of Movable Boundary Allocation Protocol, Karun Sekhri

Theses

The increasing digital communications traffic will require very high speed networks. The use of high communication speed increases the ratio between end to end propagation delay and the packet transmission time. This increase causes rapid performance deterioration and restricts the utilization of the high system bandwidth in broadcast channel based systems. Using several parallel channels in place of a single channel improves this ratio. For a given system bandwidth the total system capacity is increased by bandwidth division and parallel communication. FTDMA protocols have been suggested for the parallel channel network and these protocols are suitable for different loads. In …

Statistical Process Control For High Precision Deep Drawn Sheet Metal Parts, Sunil S. Shah

Theses

In today's world, industrial expertise has come to be judged in terms of the quality of the product. Good quality has become the ultimate aim in a manufacturing environment, which leads to many innovations for ease in the inspection of parts. In considering a metal working company like Hudson Tool & Die Company, a study of the various operations and the application of Statistical Process Control to the forming operations is performed using STORM software. Important characteristics have been carefully studied with regards to metal forming like uniform metal thickness, radius of the bend, depth of the drawing operation. In-depth …

Control Of Stress In Silicon Nitride Thin Films, Ajay Krishnan

Theses

Silicon nitride thin films of varying composition and thickness were deposited on silicon substrates by reactive rf diode sputtering of a silicon target using an argon/nitrogen gas mixture. Film stoichiometry could be controlled by varying the partial pressure of nitrogen, the total sputtering gas pressure and the target rf power. Films with refractive index of 2.01, the value for stoichiometric silicon nitride, could be obtained. Film stress was measured by wafer curvature; refractive index and thickness of deposited films were obtained by ellipsometry and interferometry measurements. The etch rate in buffered HF for films with refractive index 2.05 was 29A/min; …

Multiprocessor System Design Tutor : Expert System Approach, Rakesh Kamdar

Theses

To increase computational bandwidth and system resilience, integration of several microprocessors in a single system becomes necessary. The overall throughput and efficiency of such a system is directly dependent on the hardware and software interconnection supported by the basic microprocessor chip. Sometimes it becomes difficult to put together all the information for design criteria and all the design related formulas.

The approach made here is to continuously update the hardware and software information in the database related to a given microprocessor. This information can be accessed at any time for efficient design solution. Intel 80386 and Motorola 68020 microprocessors are …

Construction Cost Estimating In Project Management, Kalpit N. Patel

Theses

The primary objective of Cost Estimating is to support the timely generation of bid or alternative estimates. Cost Estimating also supports management analysis of estimate accuracy, reasonableness and project risk through the generation of summary reports and analysis. Estimates also provide a base of information during construction for such items as scope changes to the contract, variations in costs of the project cost, total project cost, feedback for scheduling etc.

Contruction cost estimating is the process of identifying and compiling the many items of cost that will enter into a construction project. This is a procedure that requires very detailed …

A Study Of The Effects Of Weighting Matrices In Power System State Estimation, Yanshi Wang

Theses

The effects of weighting matrices that may be used in the Weighted Least Squares (WLS) method when applied to the problem of Power System State Estimation (PSSE) are studied. These weighting matrices include the one usually used in the literature and the one used in the utility PSSE programs

The performances of these weighting matrices are compared using the Monte Carlo simulation technique.

To test the performances of the weighting matrices, a PSSE program is developed, different performance indices for state comparison are defined, and many cases are studied.

Results show that the weighting matrix usually used in literature, 1/σ², …

Investigation Of Mixed-Made Fracture In Concrete, Stylianos C. Aniftos

Theses

This study is aimed at evaluating the failure characteristics of concrete in the notched beam configuration. In general, for Mode I failure tension is commonly encountered. However, in the area of high shear stress, it remains to be a question whether shear or Mode II failure exists. Researches carried out in the past decade confirmed the existance of both Mode I and Mode II failure. It is the objective of this investigation to clarify this failure characteristics using FRANC an interactive fracture mechanics software.

The investigation carried out in this study used the experimental results of Bazant and Pfeiffer (3) …