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Articles 180991 - 181020 of 197918

Full-Text Articles in Engineering

Mass Transfer Of Hazardous Organic Compounds In Soil Matrices Relevant To Thermal Desorption/Incineration, Jong-In Dong May 1990

Mass Transfer Of Hazardous Organic Compounds In Soil Matrices Relevant To Thermal Desorption/Incineration, Jong-In Dong

Dissertations

Soils contaminated with hazardous organic compounds have been known to threaten human health both directly through various contact mechanisms and indirectly through leaching or transfer to the food chain. Thermal desorption of contaminated soil matrices with secondary treatment of the effluent gases (collection, incineration, etc) is one of most feasible and developing technologies for cleaning of contaminated soils. There is, however, little known about the mass transfer principles of organic contaminants through the heated soil matrices. The objectives of this study is, therefore, to learn and understand details of the mass transfer processes of organic compounds in these soil matrices. …


Interconnection Of X.25 Networks, Syed Ayaz Qutubuddin Ahmed May 1990

Interconnection Of X.25 Networks, Syed Ayaz Qutubuddin Ahmed

Theses

The purpose of this work was to investigate the performance of two interconnected X.25 networks via CCITT internet protocol X.75. Since internet protocol X.75 follow the same flow approach as X.25, we are allowed to model the acknowledgement queue in such a way that this queue provides a feed back path from destination to the source queue. Thus we are able to model our interconnected network as a closed queueing network with limited number of packets in transit within the network. Mean Value Analysis with Blocking (MVA) algorithm was applied to obtain the performance characteristics as the resources available were …


An Implementation Of Mht Algorithm For Adaptive Transform Coding Of Speech, Peter Battenschlag May 1990

An Implementation Of Mht Algorithm For Adaptive Transform Coding Of Speech, Peter Battenschlag

Theses

The Modified Hermite Transform (MHT), a suboptimum block transform scheme, is implemented on a TMS320C25 signal processing system with the objective of reducing the redundancy in speech signals and transmit a quantized vector representation at bitrates as less as 0.5 bits per sample.

The generation of the Hermite polynomials with a binomial and several first order IIR filter structures is presented focusing on the fact that no muliplications are required which simplifies the MHT algorithm considerably.

An assembler program performs forward and inverse transformation together with a vector quantization using adaptive bitallocation based on short-time statistics for the transform coefficients. …


Multichannel Input Moniter, Geng Lin Chen May 1990

Multichannel Input Moniter, Geng Lin Chen

Theses

In order to communicate ,with each other, people must use the same kind of language. MIDI, the Musical Instrument Digital Interface, was established as a hardware and software specification which makes the communication between musical instruments become possible.

What this thesis does is interfacing a musical instrument with other devices using MIDI protocol. The hardware is a multichannel priority interrupt system which has already been done and was included in the discussion of this thesis. The focus of this thesis is concentrated on the software development of multichannel input monitor.


Configuring Maps For A Satellite Communication Network By Self- Organization, Yizhong Chen May 1990

Configuring Maps For A Satellite Communication Network By Self- Organization, Yizhong Chen

Theses

There are several management tasks in a telecommunication network. Among which traffic management is one of the most important and difficult tasks. It is concerned with maximizing network efficiency when the network is under stress either due to overload or failure. New attempts to automate this task such as expert system based approach are yet to be perfected. In this thesis, we advocate a new concept of traffic management. Our scheme consists of two levels. At the first level, we introduce a Self-organization model to dynamically configure a map for a satellite communication network. The second level is a routing …


Prestressed Concrete Columns Under Bending And Axial Load, Ajit Chiplunkar May 1990

Prestressed Concrete Columns Under Bending And Axial Load, Ajit Chiplunkar

Theses

A general analysis and design equation for slender and nonslender prestressed concrete columns subjected to uniaxial or biaxial moments combined with axial load is proposed. The proposed equation is an extension to the one developed by Hsu for reinforced concrete columns. The analytical results of the ultimate loads of eccentrically loaded slender prestressed columns are compared with the experimental results reported by Brown and Hall and Aroni respectively. The comparative study shows that the proposed equation of interaction diagram is in good agreement with the actual tests.

The ultimate loads of biaxially loaded short columns are also compared with the …


Three Dimensional Finite Element Analysis Of A Tibial Ankle Prosthesis, Harrison Philip Crowell Iii May 1990

Three Dimensional Finite Element Analysis Of A Tibial Ankle Prosthesis, Harrison Philip Crowell Iii

Theses

In this study, three dimensional finite element analysis is used to evaluate and compare partially and fully porous coated tibial components, of an ankle prosthesis, implanted in the distal tibia. The geometry of the distal tibia is determined from measurements of cross sections of a human tibia. From the measurements, solid models of the cancellous and cortical bone are created. A solid model of the tibial component is created and positioned in the solid model of the bone. From the solid model, a finite element model is created for the partially coated case and for the fully coated case. Each …


A Micro-Based Machine Vision System, Hsueh-Chung Michael Feng May 1990

A Micro-Based Machine Vision System, Hsueh-Chung Michael Feng

Theses

In this thesis, a low-cost general purpose machine vision system based on a personal computer of the PC-XT/AT family and an electronic camera controller based upon a Motorola 6811C11 single-chip microcontroller has been designed and implemented. This work is focused on image formation. The system supports a long distance camera-computer configuration. A picture editor, generic image manipulation software was designed and implemented. A single computer can supervise multiple cameras.


Analysis Of The Effects Of Biofeedback On Cardiovascular And Neuromuscular System, Andreas T. Gikas May 1990

Analysis Of The Effects Of Biofeedback On Cardiovascular And Neuromuscular System, Andreas T. Gikas

Theses

Time series signal processing techniques (Fourier based) were applied to study the effects of biofeedback on the cardiovascular and neuromuscular system.

A medical instrumentattion system was developed to monitor ECG, EEG and EMG biopotential signals and temperature.

Data from two experiments were first analyzed. These data were from two normal male subjects who engaged in relaxation techniques (Transcendental Meditation & Imagery). If we assumed that for both subjects relaxation produced a decrease of the sympathetic activity then that resulted in a decrease of the heart rate (ECG) and an increase in skin temperature. Spectral analysis of the EEG signal showed …


The Application Of Microwave Technology To The Remediation Of Non- Volatile Organic-Contaminated Soil, Huiping Gu May 1990

The Application Of Microwave Technology To The Remediation Of Non- Volatile Organic-Contaminated Soil, Huiping Gu

Theses

The application of microwave technology to the remediation of soils contaminated with non-volatile organic chemicals is the subject of this thesis. It had been previously shown in this laboratory that volatile and semi-volatile organics could be steam distilled from soil. This study has been focussed on the applicability of microwave treatment of soil contaminated with non-volatile organics at relatively low temperatures achievable by in situ microwave treatment. Non-volatile toxics, like dioxin, pose their greatest danger when excavated and transported, according to the EPA, therefore, there is an urgent need for an in situ remediation process. Microwave treatment is one of …


Reliability Of Titanium Dioxide Capacitors, Md. Badrul Hasan May 1990

Reliability Of Titanium Dioxide Capacitors, Md. Badrul Hasan

Theses

In recent years many different materials have been investigated as potential thin-film capacitor dielectrics. Silicon monoxide (SiO) and tantalum pentoxide (Ta2O5) are the two dielectric materials that are being used by most companies.

This thesis provides some theory and experiments to evaluate the reliability of TiO2 as a material which would yield a dielectric constant much higher than Ta2O5. It has also been shown that titanium dioxide is economically and technically capable of miniaturization demanded by the latest electronic systems.

Included here are the sections covering evaporant materials and their purities, …


An Artificial Neural Network For Redundant Robot Inverse Kinematics Computation, Wibawa Utama May 1990

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 …


Simulation Of Random Packing Of Hard Spheres Using Monte Carlo Method, Sung-Ho Park May 1990

Simulation Of Random Packing Of Hard Spheres Using Monte Carlo Method, Sung-Ho Park

Theses

A computer based method of generating a random packing of hard spheres is described. Using a Monte Carlo method as employed in the field of Computational Statistical Physics, packing of hard spheres are generated and analyzed.

The mean packing fractions for the present assemblies of 1000 spheres are 0.555±0.015 after pouring and 0.582±0.018 after 10 cycles of shaking. These values are approximately 5 to 6 per cent lower than the experimental results of G.D. Scott[30], but similar with the result of Visscher & Bolsterli [17].

The mean coordination numbers are 5.97 and 6.33 for the pouring and shaking case, respectively. …


Design And Analysis Of Movable Boundary Allocation Protocol, Karun Sekhri May 1990

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 …


Control Of Stress In Silicon Nitride Thin Films, Ajay Krishnan May 1990

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 May 1990

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 May 1990

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 May 1990

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 May 1990

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) …


Experimental Evaluation Of Process Zone Deformation In Concrete, Cherng-Maou Meng May 1990

Experimental Evaluation Of Process Zone Deformation In Concrete, Cherng-Maou Meng

Theses

Concrete structures are often subjected to a variety of loading conditions. Under ultimate load design, concrete structures can resist these loads without evident deformation. However, under service, tension cracks will develop and depending on their location, they may impair load carrying capacity.

It is generally believed that microcrack development is preceeded by formation of a relatively long microcracked region. A large number of studies have indicated that due to formation of this process zone (microcracked zone), Linear Elastic Fracture Mechanics (LEFM) principles are not applicable to concrete. However, a number of nonlinear models can be developed if the length of …


Mathematical Modeling And Simulation Of The Progression Of Aids, Anju H. Nagpal May 1990

Mathematical Modeling And Simulation Of The Progression Of Aids, Anju H. Nagpal

Theses

Acquired Immunodeficiency Syndrome (AIDS) caused by Human Immunodeficiency Virus (HIV) is a pernicious disease acknowledged as a world health problem. One of the major issues in the study of AIDS is understanding the manifestation and the progression of the disease following the transmission of HIV. Unfortunately, the present state of biological knowledge does not yet give us a reliable means of evaluating these phenomena. A simulation approach is, therefore, extremely useful in predicting the various phases of the deteriorating physiological status of the patient. In the present study we have focused on the development of a mathematical model of the …


Design Of A Real Time Optical Sensor For Continuous Blood Cell Separation, Girish S. Yerande May 1990

Design Of A Real Time Optical Sensor For Continuous Blood Cell Separation, Girish S. Yerande

Theses

For continuous measurement and display of oxygen saturation and RBC content in blood during cell separation a reflection type optical sensor is designed based on the theoretical model using the photon diffusion theory. The prototype sensor consists of two arrays of light emitting diodes, red and infrared, and photodiodes. The emission wavelength of LEDs are 660 nm and 800 nm. The 800 rim which is in the infrared region is very close to isobestic value for blood. The prototype sensor is mounted on the blood cell separator equipped with an antitwister mechanism. Each LED emits a specific wavelength of light …


Biomechanical Analysis Of The Acetabulum And Acetabular Prothesis By Three Dimensional Finite Element Analysis, Mitchell J. Palmer May 1990

Biomechanical Analysis Of The Acetabulum And Acetabular Prothesis By Three Dimensional Finite Element Analysis, Mitchell J. Palmer

Theses

A biomechanical analysis modeling methodology of the acetabulum and acetabular prosthesis using three dimensional finite element analysis is presented. A simplified pelvis model is utilized which will yield accurate bone/component interfacial stresses. The SDRC IDEAS software program was used to perform the associated operations. Model generation of the simplified pelvic model and cup, finite element subdivision; material properties, restraints and load modeling are detailed. The model is comprised of 429 isoparametric elements in the simplified pelvis portion and 633 elements in the cup portion. Materials properties and loads are from the literature. The modeling methodology offers the advantages of determining …


A Study Of The Effect Of Flexibility On Manufacturing Performance, Prashanth B. Nagendra May 1990

A Study Of The Effect Of Flexibility On Manufacturing Performance, Prashanth B. Nagendra

Theses

Manufacturing flexibility has been a major topic of research in recent years. Researchers and managers are concerned about the role of flexibility in manufacturing performance. The strategic and economic impact of flexibility is of vital importance for managers in today's competitive industry.

This thesis initially provides an in-depth.perception of the prior research conducted in the area of manufacturing flexibility. Manufacturing flexibility, in this study, has been classified into four major types. Simple definitions and operational measures are provided for each of these primary types. The different factors effecting these flexibilities are identified. A new concept called the Cause-Effect-Flexibility-Technology diagrams based …


Trellis Coded Tamed Frequency Modulation In Rayleigh Fading Channels, Kiran R. Patel May 1990

Trellis Coded Tamed Frequency Modulation In Rayleigh Fading Channels, Kiran R. Patel

Theses

It is usually difficult to reduce the effects of channel impairements on transmitted information. A fading channel is one such media in which digital communications system operates. A signal is subject to distortion in amplitude and phase when propagating towards the receiver. This puts constraint in required SNR at the receiver, for given performance. Various modulation/coding and demodulation/decoding techniques are employed to lessen the effects of fading. Bit error rate is a performance parameter that sets the criteria for signal design, system architecture and performance.

Here, a slow Rayleigh fading channel with three propagation paths possesing a scattering function of …


Lossless Image Data Compression Techniques Using High Order Markov Arithmetic Encoding, Santo Politi May 1990

Lossless Image Data Compression Techniques Using High Order Markov Arithmetic Encoding, Santo Politi

Theses

It is difficult to compress digital images with acceptable ratios if a distortion is not acceptable. The lack of a rule based structure as in a language is one of the main reasons. In this work a number of algorithms for lossless image data compression are considered. The coding and the modeling aspects are treated separately. Different approaches are proposed to combine. Markov Arithmetic Encoding, a very efficient plain text encoding scheme, with source modeling algorithms to obtain higher compressibility. A modular approach is selected which enables combining various models. Model statistics are studied for further improvements. The schemes presented …


Single Token Integrated Dama In Multiple Bus Local Networks, Srinivasan Ramadurai May 1990

Single Token Integrated Dama In Multiple Bus Local Networks, Srinivasan Ramadurai

Theses

Multiple-bus local Networks (MBLNs) provide an architecturally simple solutions to serve high-reliability-high capacity local area networks(LAN) applications. Access mechanisms for MBLNs possessing stability and favorable delay characteristics are developed in this thesis. A new technique is proposed that uses a single explicit token to achieve demand assignment multiple access (DAMA) to arbitrate access on all the buses in the system. Analytical model was developed and compared to simulation results that indicates performance improvement in terms of delay characteristics of the system of buses.


Effective Use Of Management Information Systems In Manufacturing, Bhavik Shah May 1990

Effective Use Of Management Information Systems In Manufacturing, Bhavik Shah

Theses

Information is the catalyst of management and the ingredient that coalesces the managerial functions of planning, organizing, actuating and controlling. The implementation of management information system (MIS) provides the vehicle by which management process can be administered and integrated. Information is at the core of creative thinking, which leads to new ways of improving products, process and services to the invention of new devices and to discovery of new marketable concepts. Thus information for an organization has a dual application for internal operation and external marketing potential.

The organization studied was a small to medium sized batch manufacturer of healthcare …


Temperature Dependent Current-Voltage Characteristics Of Tisi2/N+/P Silicon Shallow Junctions, Bhupendra M. Shah May 1990

Temperature Dependent Current-Voltage Characteristics Of Tisi2/N+/P Silicon Shallow Junctions, Bhupendra M. Shah

Theses

Analyses of temperature dependent current-voltage characteristics, of titanium silicide films on n+/p silicon shallow junctions, has been presented here. The fabrication technique involves the formation of shallow pn junctions, by ion-implantation of As+ through titanium films evaporated on P type silicon. The improvement of the activation of dopants has been fulfilled by different annealing processes in conjunction with the dopant drive-in. Electrical measurement of temperature dependent current-voltage technique has been employed to characterize these devices. The temperature dependent factors such as energy bandgap narrowing, majority carrier degeneracy, diffusivities, mobilities and minority carrier life time are evaluated by using key approximations.


Application Specific Integrated Circuits For Single Board Computer, Ximing Shi May 1990

Application Specific Integrated Circuits For Single Board Computer, Ximing Shi

Theses

A single board computer is the central part of many microprocessor-based instruments. The implementation of the logic portion of a single board computer using Xilinx Logic Cell Array makes the computer system more powerful. Xilinx Logic Cell Array is a new kind of Programmable Gate Array in application specific integrated circuit with high design flexibility and functional density. The XACT Development System provides schematic capture and auto place-and-route for design entry.

In this thesis, a Xilinx Logic Cell Array was developed and implemented in the 8052AH-Basic based Single Board Computer design. Also, the logic and timing verification and simulation of …