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Articles 70681 - 70710 of 77551

Full-Text Articles in Engineering

Modelling And Parameter Estimation In Clinical Electrooculography, Shengche Hsu May 1989

Modelling And Parameter Estimation In Clinical Electrooculography, Shengche Hsu

Theses

The Corneoretinal potential (CRP) was discovered in 1848. Its response to changes in light intensity can provide information relevant in the diagnosis of some retinal degenerative disorders. The indirectly measured CRP is referred to as electro-oculography (EOG). A system for automatic data acquisition and modelling, providing graphic presentation, data processing and file management, has been developed. A linear feedback model is proposed to represent the dynamics of the EOG signal. Model parameters are estimated by the nonlinear least-square method. The effect of measurement time on the reliability of parameter estimation is discussed.


An Interactive Graphics Capability For Numerical Design Optimization, Abbay P. Joshi May 1989

An Interactive Graphics Capability For Numerical Design Optimization, Abbay P. Joshi

Theses

Hierarchical Object Oriented Program Software [HOOPS] is used here to develop an interactive graphical interface for the design optimization program CADOP5. A preprocessor provides the user with button menu options. Using various buttons like Variable Button, Obj Button, Parameter Button, etc. the user can interactively define problem variables, parameters and limits as well as interactively modify the behavior and the constraint functions. The post processor displays variable values for three consecutive design cycle in the form of bar charts. Objective function values are plotted against the number of design cycle. Using this information the user can determine if the solution …


The Kinetics Of Degradation Of 1,2-Dichloroethane, 1,1,1-Trichloroethane And 1,1,2,2-Tetrachloroethane In A Photoreactor Using Ozone, Hydrogen-Peroxide And Ultraviolet Radiation, Yuan-Shen Li May 1989

The Kinetics Of Degradation Of 1,2-Dichloroethane, 1,1,1-Trichloroethane And 1,1,2,2-Tetrachloroethane In A Photoreactor Using Ozone, Hydrogen-Peroxide And Ultraviolet Radiation, Yuan-Shen Li

Theses

The experiments to oxidize the refractory chemicals, 1,2- Dichloroethane, 1,1,1-Trichlotoethane and 1,1,2,2- Tetrachloroethane using Ozone, Hydrogen Peroxide and Ultraviolet Radiation have been conducted in a ss-304 photoreactor. The reaction kinetic models have been proposed and through the experiments we demonstrate that these models for these compounds perfectly. Analysis is done by gas chromatograph for the substrate concentration and the gas/liquid mass transfer coefficients are calculated. The reaction late constants are determined by use of the Rosenbrock Hillclimb Optimization Algorithm in conjunction with the Fourth-Order Runge- Kutta method on a digital computer. By comparing the effects of O3,O3 …


User Interactive Compensation For Si/So Systems Via Root-Locus, Shih-Mim Liu May 1989

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.


Removal Of Contaminants From Clay Soils By Thermal Desorption, Wen-Ming Mao May 1989

Removal Of Contaminants From Clay Soils By Thermal Desorption, Wen-Ming Mao

Theses

The objective of this study was to investigate the removal of contaminants from clay soils by thermal treatment. There were two phases involved in this project. The first was a study of equilibrium adsorption of clay - organics study, and the second was the determination of the thermal desorption characteristics.

Three organics, phenol, chlorophenol, and chlorobenzene and one clay soil, bentonite, were selected for these studies. The first phase, involved the simulation of the isothermal adsorption simulated the process of contaminants being sorbed onto bentonite. Three different isotherm models,viz, Linear isotherm, Freundlich isotherm, and Langmuir isotherm were evaluated with experimental …


Digital Image Restoration Using Power Spectrum Equalization Filtering Technique, Debdatta Sen May 1989

Digital Image Restoration Using Power Spectrum Equalization Filtering Technique, Debdatta Sen

Theses

Digital deblurring of micro-circulatory images using both homomorphic and power spectrum equalization filtering are considered. An existing homomorphic filter was modified by changing filter parameters. This permitted an image with better contrast to be obtained. The power spectrum equalization approach consists of modeling and characterization of degradation and estimation of the power spectrum of the image using the Welch method. The restoration is considered from the point of view of spatial-frequency domain descriptions of images. Consideration is restricted to degradations arising from additive noise and spatially invariant linear blurring. The filter restores the power spectrum of the image to what …


Multiphase Solid-Liquid And Solid-Liquid-Gas Mixing In Stirred Tanks, Jessyca Susanto May 1989

Multiphase Solid-Liquid And Solid-Liquid-Gas Mixing In Stirred Tanks, Jessyca Susanto

Theses

A number of investigations can be found in the literature on the effect of mixing parameters on solid-liquid dispersions in agitated systems. However, the determination of the effect of impeller clearance on minimum suspension speed has received little attention. This work is mainly focused on the determination of the effect of the impeller clearance on Njs (the minimum agitation speed required for complete solid-liquid dispersion) and its corresponding power consumption, using both radial and axial impellers in stirred tanks. In addition, the effect of other significant parameters on Njs was also investigated.

The importance of the impeller clearance …


Trellis Coded Partial-Response Channels, Kumari Yalamanchili May 1989

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 …


Methods Of Achieving High Speed On Data Flow Machines, Chung-Lin Yu May 1989

Methods Of Achieving High Speed On Data Flow Machines, Chung-Lin Yu

Theses

Simultaneity is a key to high speed and large computation. Assuming hardware components of a given speed, it is the only remaining consideration in achieving raw speed. Simultaneity can be shackled by dependencies, however, and years of hardware and software work have been devoted to understanding the types of dependencies and how they can be obeyed or removed from a computation.

In this thesis, the principles of the data flow machines and the structure of the data flow languages are illustrated. Various methods of achieving high speed are discussed. These methods include streams, Lenient Cons (I-structure), and dependence-driven computation, which …


Image Coding With Switchable Dynamic Quantizers, Shing-Sun Yu May 1989

Image Coding With Switchable Dynamic Quantizers, Shing-Sun Yu

Theses

In this thesis, an image coding scheme based upon dynamic quantizations and Differential Pulse Code Miodulalton (DPCM) is studied for application in digital image transmission. This scheme achieves a degree of data compression, and at the same time, maintains an acceptable degraded Mean Square Error (MSE) in the reproduced image. The image to be transmitted is first divided into blocks and each block is then quantized before transmission. The dynamic quantizations including DPCM) are dynamically utilized in reducing the transmission rate while maintaining a desirable quantization noise level. Results of computer simulation of the proposed scheme demonstrate that the switchable …


Algorithms And Analysis Of Dialogue Time Patterns, Muhammad Saleem Akhtar May 1989

Algorithms And Analysis Of Dialogue Time Patterns, Muhammad Saleem Akhtar

Theses

The characteristics of a conversation between two people can be determined not only what they say to each other, but also by the rhythm of their dialogue. Their moods, attitudes and attributes may be conveyed in part by time patterns of the speech. The programs described herein can be useful in exploring the relationship between dialogue time patterns and other psychological aspects of human behavior. The measurements of these time patterns can be quickly, inexpensively, and reliably accomplished by the use of a PC.

The programs described herein are capable of calculating the variabilities, the time durations and frequencies of …


Unified Study Of Trellis Encoded Correlative-Fm, K. Narendra Bhat May 1989

Unified Study Of Trellis Encoded Correlative-Fm, K. Narendra Bhat

Theses

Trellis encoding of correlative-FM is studied from the point of view of the overall structure, performance, bandwidth occupancy, and complexity. Here, correlative (partial-response) coding is used to improve the bandwidth efficiency of MSK (Minimum-Shift Keying) at the expense of performance. Then, trellis codes are used to improve the error-rate performance of the corresponding correlative-FM scheme with little or no increase in bandwidth occupancy (compared to uncoded MSK). In a sense, this is similar to Ungerboeck's coding for (memoryless) PSK modulation.

A new encoding approach, called matched encoding, is used here that produces trellis coded modulations achieving greater coding gains than …


Non Invasive Monitoring Of Cardiovascular Dynamics Through A Microwave Interferometer, Suresh Chakravarthi May 1989

Non Invasive Monitoring Of Cardiovascular Dynamics Through A Microwave Interferometer, Suresh Chakravarthi

Theses

The microwave interferometer is utilized to pick up vibrations of the anterior (front) chest wall, produced by cardiac activity. This instrument is capable of remotely measuring the vibrations at distances up to four feet through clothing, by using low level microwave energy at 9.3 Ghz. The vibrations picked up from subjects are filtered, and processed through a PC to correlate with EKG signals, and thereby evaluate the instrument as a non-invasive, non-contacting cardiac monitor.

The subjects lie on their back with the microwave energy illuminating their chest, and their cardiovascular dynamics are recorded simultaneously with EKG signals. The EKG is …


One-Dimensional Parametric Inverse Scattering For Lossless Dispersive Media, Frank Gangi May 1989

One-Dimensional Parametric Inverse Scattering For Lossless Dispersive Media, Frank Gangi

Theses

In this thesis, the effects of high frequency noise on a perturbational inversion algorithm for a stratified dispersive medium are investigated. It is shown that the perturbational algorithm becomes unstable under high frequency noise. The physical origin of this instability is discussed.

In order to enhance the robustness of the perturbational inverse scattering solution, a parametric inversion algorithm is implemented. The improvement by the use of a parametric inversion is given quantitatively by the profile-to-error ratio (PER). Examples of the two-pole and the three-pole reflection coefficients are compared and contrasted.


A Cmos Robotic Lan Interface Integrated Circuit Design, Yong-Bin Kim May 1989

A Cmos Robotic Lan Interface Integrated Circuit Design, Yong-Bin Kim

Theses

This thesis describes the design including specification, schematics,logic and circuit simulation, and standard cell layout for a CMOS mixed-mode I.C. for interfacing sensors into a robotics local area network. The network accepts up to 256 interface chips as nodes in each area. A simple network protocol permits acquisition of digital data from the interface nodes through gateways into ARCNET and MAP.

The sensor chip interfaces directly from analog signals of range 0-1V and 0-20mV. It contains an 8-bit ADC. The application I.C. interfaces to sensors for pressure, tactile stress, humidity, temperature, etc.

Each of the sensor interface node I.C.s is …


The Rate Of Vibrational Segregation In Particulate Materials, Yidan Lan May 1989

The Rate Of Vibrational Segregation In Particulate Materials, Yidan Lan

Theses

The rate of vibratory size segregation has been modeled in multi-component size systems as a process of mutual sorting between each size species. The concept of mutual sorting is introduced from which generalized expressions are derived for the rates of change of the local concentration of each size species. In a binary system, the expressions simplify to give the expected result that the segregation rates for the large and small particles are equal but of opposite sign. Also, in these systems, the segregation rate is described by measuring the rising speed of the interface between the small and large particles. …


Nonlinear, Metal-Clad Optical Waveguide, Bhavesh Patel May 1989

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 …


Experimental Evaluation Of J-Integral For Fiber Reinforced Concrete Subjected To Impact Loading, Piyushkumar Patel May 1989

Experimental Evaluation Of J-Integral For Fiber Reinforced Concrete Subjected To Impact Loading, Piyushkumar Patel

Theses

This research presents an experimental Evaluation of J-Integral for Fiber Reinforced Concrete Subjected to Impact Loading. Three-point edge notched bend specimen were employed in evaluation of J-Integral using both the multi-specimen, and the single specimen techniques. In the multi-specimen technique three different notch lengths were employed for extracting the energetic fracture parameter JIc. In the single specimen technique, the method developed by Rice[13] was used to evaluate JIc at three different notch lengths.

Different proportions of fiber were employed in determining the JIc values. Experimental results from present study indicates that the JIc values calculated …


Study Of Ionized Cluster Beam Techniques For Reactive Deposition Of Gallium Nitride Thin Films, Jyh Sheen May 1989

Study Of Ionized Cluster Beam Techniques For Reactive Deposition Of Gallium Nitride Thin Films, Jyh Sheen

Theses

This thesis is divided into two parts. The first part investigates the Ionized Cluster Beam( ICB ) technique through measurements of the energy of ionized gallium beam. The presence of ions and their kinetic energy in the ICB technique is advantageous in the formation process of thin film. The results of retarding potential measurement are comparable with the presence of clusters as large as 500 atoms. The second part examines the formation of gallium nitride thin film. In order to enhance the reaction of gallium and nitrogen, dissociation of molecular nitrogen by microwave discharge method was used to generate atomic …


Firmware Toolkit For Larynx Synchronous D.S.P., Shih-Chieh Su May 1989

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 …


Electrical Insulation Screening For Reliability, Vinu Sundaresan May 1989

Electrical Insulation Screening For Reliability, Vinu Sundaresan

Theses

This thesis work includes an investigation on the use of electrical noise for the screening of dielectric sheet material for reliability. Three different high voltage insulation sheet materials, commonly used in power industry, have been studied. These are - Westinghouse Polyester resin coated glass cloth, Dupont ‘NOMEX' aramid calendared paper and a cotton rag commonly known as Fishpaper. Samples of each material have been categorized into low noise and high noise units. Subsequently, these samples were subjected to accelerated life testing.

It is seen that units having high noise are failing quicker compared to low noise units when subjected to …


Optimal Design Of Prestressed Concrete Members Using Numerical Techniques, Nasseruddin Syed May 1989

Optimal Design Of Prestressed Concrete Members Using Numerical Techniques, Nasseruddin Syed

Theses

This research consists of the application of nonlinear optimization techniques for the economical design of prestressed concrete members. A computer program using Lattice and Matrix methods of optimization is employed for least weight design of I-shaped prestressed concrete girders. The program calculates the most optimum values of the cross-sectional dimensions.It has the freedom to impose any constraints on any of the design variables, including sectional dimensions, eccentricities, concrete cover and limiting stresses.

Comparison of results obtained in this thesis with other analytical methods indicate that with the advent of computers, the numerical methods have a definite advantage over other analytical …


Spectrum Analysis Of Heart Rate Variability, Xuming Wang May 1989

Spectrum Analysis Of Heart Rate Variability, Xuming Wang

Theses

This research investigated the respiratory influence on heart rate variability. The heart rate spectrum was obtained from the heart rate variability signal which was extracted from the electrocardiogram We then studied the magnitude of the respiration peak in the heart rate spectrum and examined the dependence of the magnitude of this peak on breathing frequency, subject and day.

An experiment designed to simultaneously acquire the electrocardiogram and the respiration signal was conducted on ten people ranging from 22 to 55 years of age (3 females, 7 males). Three tests were performed on each subject. In each test, 2 different postures …


A Study Of Volatile Organic Compound Emissions In The Ambient Air Of A Sanitary Landfill In Richard W. Dekorte State Park, New Jersey, Minsen Gao May 1989

A Study Of Volatile Organic Compound Emissions In The Ambient Air Of A Sanitary Landfill In Richard W. Dekorte State Park, New Jersey, Minsen Gao

Theses

A study was made of 15 volatile organic compounds (VOCs) in the ambient air emissions of a sanitary landfill located at Richard W. DeKorte Park, Lyndhurst, New Jersey. The samples were collected from July 1986 to September 1987 at 10 designated landfill sites over the selected time period from 4 to 24 hours by drawing the air to be analyzed through a Tenax trap. An average 10 to 15 liters of air sample was collected each time. Sample analysis is done on a Varian Gas Chromatograph (GC) combined with a Tekmar Thermal Desorber. A standard gas mixture of the 15 …


High Temperature Resistant Crosslinked Phenol, O-Chlorophenol And Formaldehyde Copolymer Fiber, Suh Joon Han May 1989

High Temperature Resistant Crosslinked Phenol, O-Chlorophenol And Formaldehyde Copolymer Fiber, Suh Joon Han

Theses

Phenolic copolymer fibers which possess clearly distinguishable physical and chemical properties from other synthetic and natural fibers were prepared. Acid catalyzed condensation polymerization of phenol, formaldehyde and o-chiorophenol was carried out by a two-stage polymerization. Initially, phenol-formaldehyde and o-chlorophenol-formaldehyde oligomers were separately prepared by refluxing the corresponding monomers at 100°C under strong agitation. At the second stage, these two oligomers were combined and vacuum-distilled to form a block copolymer which was then melt spinned into fibers and subsequently cured by succinyl chloride in a mineral spirit. Using a flame test and thermogravimetric analysis, it was found that these cured fibers …


Statistical Multiplexing Of Video Sources For Packet Switching Networks, Krishna Kancherla May 1989

Statistical Multiplexing Of Video Sources For Packet Switching Networks, Krishna Kancherla

Theses

Communication networks are fast evolving towards truly integrated networks handling all types of traffic. They employ integrated switching technologies for voice. video and data. Statistical or asynchronous time division multiplexing of full motion video sources is an initial step towards packetized video networks. The main goal is to utilize the common communication channel efficiently, without loosing quality at the receiver. This work discusses the concept of using statistical multiplexing for packet video communications. The topology of a single internal packet network to support ISDN services has been adopted. Simulations have been carried out to demonstrate the statistical smoothing effect of …


The Application Of The Ordered List Method And The Dynamic Programming To The Unit Commitment, Hoang Uong May 1989

The Application Of The Ordered List Method And The Dynamic Programming To The Unit Commitment, Hoang Uong

Dissertations and Theses

The thesis presents a method of committing generating units in a hydro-thermal power system within practical computer resources such as computer time and data storage.


Mine Warfare In The Russian And Soviet Navies, Jeffrey K. Bray May 1989

Mine Warfare In The Russian And Soviet Navies, Jeffrey K. Bray

Graduate Program in International Studies Theses & Dissertations

This thesis examines the development of technology, tactics, strategy, and organization of mine warfare in the Russian and Soviet navies from 1807 to the present. The author reviews the trials and tribulations of the development of naval mines and their employment within these two navies. This development has been primarily driven by the needs of war and advances of technology. In spite of occasional setbacks, the Russian and Soviet mine warfare forces continued to provide support to the overall naval and central policies of their respective governments. This support has often been during times of high tension and limited resources. …


Microprocessor Based Protection Of Induction Motors Using Thermal, Mechanical, And Skin Effect Electrical Models To Predict Motor Temperature Rise, Nader S. Moharari May 1989

Microprocessor Based Protection Of Induction Motors Using Thermal, Mechanical, And Skin Effect Electrical Models To Predict Motor Temperature Rise, Nader S. Moharari

Masters Theses and Doctoral Dissertations

This study investigates induction motor performance during a variety of system and load conditions. A computer simulation is used to characterize the motor behavior during normal operation, lockedrotor case, high inertia loading, and overloading conditions. Motor temperature at critical points is estimated. A microprocessor protection scheme based on motor temperature is proposed. Previous studies assume a linear relationship between motor impedance and frequency when calculating motor temperature. In this study an electrical model, based on Maxwell's equations, is used in conjunction with a mechanical model, to represent the motor during dynamic state conditions. The model accounts for the rotor bar …


Density-Dependent Convective Flow In Closed Basins, Kim L. Mccleary May 1989

Density-Dependent Convective Flow In Closed Basins, Kim L. Mccleary

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Great Basin is a region of the Basin and Range Physiographic Province, which is completely isolated hydrologically from the sea. All precipitation that falls within the Great Basin is lost from the land surface or from the surface of closed inland lakes through evapotranspiration. Playas are often found at the base of these undrained basins. This study focuses on subsurface groundwater flow patterns in closed basins. Because all discharge from the basins occurs via evapotranspiration on and near the playa, the water table of the aquifer beneath the playa is often just below the ground surface. Fluctuations of the …