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1991

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Articles 451 - 480 of 1363

Full-Text Articles in Engineering

Report Of The 12th F.V. Hunt Postdoctoral Fellow (1989-1990), E. Carr Everbach Jun 1991

Report Of The 12th F.V. Hunt Postdoctoral Fellow (1989-1990), E. Carr Everbach

Engineering Faculty Works

No abstract provided.


Bs News Jun 1991

Bs News

Building Services Engineering

No abstract provided.


Tensile Behavior Of Hybrid Woven-Fabric-Composites, Hussein M Massoud Jun 1991

Tensile Behavior Of Hybrid Woven-Fabric-Composites, Hussein M Massoud

Archived Theses and Dissertations

No abstract provided.


Operations Research In A New Spanish Air Force Planning System, Antonio Valderrabano Jun 1991

Operations Research In A New Spanish Air Force Planning System, Antonio Valderrabano

Theses and Dissertations

The focus of this research effort was to determine a new Spanish Air Force Planning System. Today's highly technological weapon systems are very expensive, and resources are very scarce. So its selection has to be done very carefully. This process can allow high flexibility, be helpful facing the budgetary problems for all the Air Forces, and also can be easily integrated in a joint defense system. The path defined in this thesis is able to be adapted for different situations. It can be useful for other Services or countries, when their own peculiarities have been set up on the defined …


1-Nitronaphthalene Causes Ultrastructural Changes Primarily In Nonciliated Bronchiolar Epithelium Followed By Ciliated Epithelium In The Rat, John-Michael Sauer Jun 1991

1-Nitronaphthalene Causes Ultrastructural Changes Primarily In Nonciliated Bronchiolar Epithelium Followed By Ciliated Epithelium In The Rat, John-Michael Sauer

Masters Theses

This study describes morphological changes in the lung at several time intervals following a single injection of 1-Nitronaphthalene (100 mg/kg intraperitoneal) in male Sprague-Dawley rats using transmission and scanning electron microscopy. Dilation of the smooth endoplasmic reticulum and mitochondrial distension in the nonciliated bronchiolar (Clara) cells was apparent as early as 1 hour after injection, while adjacent ciliated cell showed minimal changes. At 6 hours, when respiratory distress was apparent in the animals, Clara and ciliated cells exhibited chromatin clumping, loss of mitochondrial cristae and cytoplasmic vacuolization. Also at 6 hours, the interstitial area around the terminal bronchioles was infiltrated …


Mosfet Audio Amplifier, Jeff Argast Jun 1991

Mosfet Audio Amplifier, Jeff Argast

Undergraduate Honors Capstone Projects

My senior project is an audio amplifier utilizing MOSFETs as the output transistors to drive the speaker. Within this document I cover the details of designing an amplifier, and the methods used to build it.

The most important part of the project is the output stage. In this section I chose MOSFETs over BJTs. Several advantages ensued from this decision, resulting in a simple design.

Further, the transformer must be able to supply the necessary currents for the transistors. Because large musical peaks are possible, resulting in sizable power surges, I had to obtain a large transformer with adequate specifications. …


Pump Polarization Effects In Cw Dye Lasers, Lee W. Casperson, W. J. Sandle, A. C. Wilson, D. M. Warrington, R. J. Ballagh Jun 1991

Pump Polarization Effects In Cw Dye Lasers, Lee W. Casperson, W. J. Sandle, A. C. Wilson, D. M. Warrington, R. J. Ballagh

Electrical and Computer Engineering Faculty Publications and Presentations

The effects of pump polarization on the performance of cw dye lasers have been investigated. A recently developed semiclassical model for synchronously pumped mode‐locked dye lasers is adapted to the problem of cw dye‐laser oscillation, and analytic expressions are obtained for the relationship between the pump power, pump polarization, and dye‐laser output power. The theoretical results are compared with experimental data obtained using an argon‐laser‐pumped rhodamine 6G dye laser.


A Vision System Model, Erik J. Fretheim Jun 1991

A Vision System Model, Erik J. Fretheim

Theses and Dissertations

This dissertation provides four major contributions to the field of vision research. The first contribution is a general vision system model. The model, which blends biological as well as technological methods into a coherent approach to vision, will provide a basis for implementing vision systems. The second contribution of this dissertation is to demonstrate particular implementations of portions of the model. These implementations will include methods for using Gabor wavelets in edge detection, in preprocessing images for use as feature vectors in backpropagation neural networks, and as basis functions in a recognition/reconstruction network, as well as methods for integrating color …


Spaceborne Radar Measurement Of Wind Velocity Over The Ocean-An Overview Of The Nscat Scatterometer System, David G. Long, F. M. Naderi, Michael H. Freilich Jun 1991

Spaceborne Radar Measurement Of Wind Velocity Over The Ocean-An Overview Of The Nscat Scatterometer System, David G. Long, F. M. Naderi, Michael H. Freilich

Faculty Publications

Scatterometry and scatterometer design issues are reviewed. The design of the NASA Scatterometer (NSCAT) to be flown on the Japanese ADEOS mission is presented. Building on Seasat experience, the NSCAT system includes several enhancements, such as three antenna azimuths in each of two swaths, and an onboard digital Doppler processor to allow backscatter measurements to be colocated everywhere within the orbit. These enhancements will greatly increase the quality of the NSCAT wind data. The ground processing of data is discussed, and scatterometers of the next decade are briefly described.


Mathematical Modeling Of Mass Transfer In Microvascular Wall And Interstitial Space, Daekyung Kim May 1991

Mathematical Modeling Of Mass Transfer In Microvascular Wall And Interstitial Space, Daekyung Kim

Dissertations

The dynamics of macromolecular transport across the microvascular wall and into the adjoining interstitial space was studied in the hamster cheek pouch using intravital fluorescence microscopy in combination with digital image processing. Fluorescein isothiocyanate-labe led dextrans (FITC-Dx) of 70,000 and 150,000 daltons were used as tracers. In each experiment, the time-dependent extravasation of FITC-Dx from a leakage site in a blood vessel was videotaped for about 2 hours. The macromolecular transport from individual microvessels was quantified by digital video-image processing. Histograms of the light intensity distributions for selected fields at various times were obtained and then converted to the interstitial …


The Theory Of Bootstrapped Algorithms And Their Applications To Cross Polarization Interference Cancelation, Abdulkadir Dinc May 1991

The Theory Of Bootstrapped Algorithms And Their Applications To Cross Polarization Interference Cancelation, Abdulkadir Dinc

Dissertations

Dual-polarized transmission has become an important method for frequency re-use, particularly in satellite and microwave radio communication. Nevertheless, cross-polarization interference, which is inherent to this method, may cause degradation in system performance.

Different canceler [sic] structures have been proposed to mitigate the effect of cross-polarization. Among these are the diagonalizer, the least mean square (LMS) canceler [sic] and the bootstrapped cancelers [sic]. Bootstrapped canceler [sic] schemes have been proposed and implemented in different applications, such as satellites, tactical communications, and quadrature amplitude madulation [sic] (QAM) dual polarized microwave radio. Nevertheless, no attempt was made in the past to quantify the …


Mathematical Modeling Of Chemical Vapor Deposition Processes And Its Application To Thin Film Technology, Norman W. Loney May 1991

Mathematical Modeling Of Chemical Vapor Deposition Processes And Its Application To Thin Film Technology, Norman W. Loney

Dissertations

A number of workers in the field of Chemical vapor deposition (CVD) have presented mathematical models in the literature. Some workers were able to produce analytical expressions for the interwafer concentration profile. These analytical expressions were based entirely on zero or first order chemical reaction rates. Until now, it appears that a chemical reaction rate expression that is not zero or first order directly, must be handled by a numerical scheme.

Presented herein is a mathematical model with an analytical interwafer concentration profile. This concentration profile is neither zero nor first order but shifts from zero to first order as …


Investigation Of Stagnation Flow Heat Transfer For A Heated Horizontal Round Plate, Ching-Hua Wei May 1991

Investigation Of Stagnation Flow Heat Transfer For A Heated Horizontal Round Plate, Ching-Hua Wei

Dissertations

The heat transfer characteristics in stagnation flow are investigated through three cases in this study. The first is forced convection by an array of air jets; the second is free convection of a downward-facing heated round plate; the third is free convection of an upward-facing heated round plate.

The first case is investigated by systematic experiments which examine the heat transfer characteristics mainly by five air jets impinging normally to a flat plate, with varying nozzle diameters, and Reynolds numbers, at different distances between the nozzles and the plate. The empirical formulas of heat transfer around the stagnation point and …


Kinetic Studies On Pyrolytic And Oxidative Decomposition Of Chlorocarbons In A Tubular Flow Reactor, Yang Soo Won May 1991

Kinetic Studies On Pyrolytic And Oxidative Decomposition Of Chlorocarbons In A Tubular Flow Reactor, Yang Soo Won

Dissertations

Chloroform decay and product distributions were distinctly different in the absence and presence of added O2 and/or CH4. Increases in O2 concentration were observed to speed reagent loss, with a slower decay of chloroform observed for the CHCl3/CH4/Ar pyrolysis system. In CHCl3/CH4/O2, the major products were C2Cl4, CH2CCl2, C2HCl3, CO and CO2 over a wide temperature range. Minor products included CH2Cl2, CH3Cl, and C2H3Cl. When CH4 reactant was not present, …


Adiabatic Kinetic Studies Of The Cytidine/Acetic Anhydride Reaction By Utilizing Temperature Versus Time Data, Joseph John Shatynski May 1991

Adiabatic Kinetic Studies Of The Cytidine/Acetic Anhydride Reaction By Utilizing Temperature Versus Time Data, Joseph John Shatynski

Theses

It is possible to predict the kinetics of a reaction by using temperature versus time data under adiabatic conditions. This method was used for the cytidine/acetic anhydride reaction using a RC1 Mettler Reaction Calorimeter.

The authenticity of the experimental adiabatic system was verified by determining the kinetic parameters of a known reaction (hydrolysis of acetic anhydride) and comparing them to literature values.

For example, the average experimental activation energy, heat of reaction, and ln k0 values for the hydrolysis of acetic anhydride were 11.2 ±.5 kcal/gmole, -14.4 ± .2 kcal/gmole, and 12.74 ± .94 sec-1, respectfully, while …


Performance Analysis Of Symbol Timing Recovery Circuits Employed In Digital Communications Systems, Elisha Yegal Bar-Ness May 1991

Performance Analysis Of Symbol Timing Recovery Circuits Employed In Digital Communications Systems, Elisha Yegal Bar-Ness

Theses

An analytical approach is presented for the jitter performance of a timing recovery circuit consisting of a prefilter, a zero-memory nonlinear device, and a narrow band postfilter tuned to the pulse repetition frequency. Assuming first a squarer type of nonlinearity, analytical expressions for the rms jitter in the timing wave are obtained as a function of the pre and post filtering characteristics. These expressions are suitable for judging the case where the baseband signal is bandlimited. Also for some specific examples, the jitter performance of this kind of STR circuit is evaluated.

Secondly, a general type of nonlinerity is assumed, …


Development Of A Classification And Coding System For Computer-Aided Process Planning, Shilpan K. Patel May 1991

Development Of A Classification And Coding System For Computer-Aided Process Planning, Shilpan K. Patel

Theses

The chore of this work was to develop a Group Technology Classification Code which can represent the full gamut of simple, rotational parts. The automated coding plan is developed to alleviate the endeavor of the process planner to plan the tasks related to the manufacturing of a specific part. The 15 digits were devised from the Japanese KK-3 Classification and Coding system. The KK-3 System contains 21 digits. Our aim is to minimize the code length, and concurrently to eliminate the redundancies. As a result, a 15 digit G.T. Code is created. The proposed plan also generates the operation logic …


Multistage Interconnection Networks : Improved Routing Algorithms And Fault Tolerance, Kuo-Yu Chen May 1991

Multistage Interconnection Networks : Improved Routing Algorithms And Fault Tolerance, Kuo-Yu Chen

Theses

Multistage interconnection networks for use by multiprocessor systems are optimal in terms of the number of switching element, but the routing algorithms used to set up these networks are suboptimal in terms of time. The network set-up time and reliability are the major factors to affect the performance of multistage interconnection networks. This work improves routing on Benes and Clos networks as well as the fault tolerant capability. The permutation representation is examined as well as the Clos and Benes networks. A modified edge coloring algorithm is applied to the regular bipartite multigraph which represents a Clos network. The looping …


Dynamic Analysis Of The Generalized Slider Crank, Sahidur Rahman May 1991

Dynamic Analysis Of The Generalized Slider Crank, Sahidur Rahman

Theses

A numerical technique is used to analyze the kinematics of the generalized slider crank mechanism and an analytical technique to derive dynamic force equations for that mechanism has been formulated. The numerical technique used for displacement analysis is based on a combination of Newton-Raphson and Davidon-Fletcher-Powell optimization algorithm using dual-number coordinate-transformation matrices. Velocity analysis is performed by using a dual number method. Finally, dynamic force analysis is accomplished on the basis of the dual-Euler equation and D'Alembert's principle. The approach is developed in such a manner that a digital computer can detect when a solution is possible and then solve …


Task Scheduling For Fms Based On Genetic Algorithm, Hung-Yuan Li May 1991

Task Scheduling For Fms Based On Genetic Algorithm, Hung-Yuan Li

Theses

A Flexible Manufacturing System (FMS) consisting of p automated guided vehicles (AGV's), m workstations and n tasks is studied. The main problem investigated in this thesis is to find an optimal or suboptimal task scheduling for p AGV's among m workstations to complete n tasks.

An efficient approach based on genetic algorithms has been designed and implemented to solve the problem of task scheduling for a FMS. Near-optimal, or even optimal, task scheduling is accomplished by genetic algorithms. Simulation results on the algorithm are also discussed.


Off-Line Programming Using Igrip, Narahari K. Bhandary May 1991

Off-Line Programming Using Igrip, Narahari K. Bhandary

Theses

AT&T's FWS-200 (Flexible Work Station) has been modeled and simulated to implement Off-Line Programming (OLP). IGRIP (Interactive Graphics Robot Instruction Program) from Deneb Robotics, Inc. has been used to simulate the FWS operation.

A GSL(Graphics Simulation Language) program has been used to simulate the chip placements during PCB assembly. The program leads the user through the motions of chip placement, and after the simulation run downloads the motion sequence to the FWS. The animation sequences of the FWS have been downloaded to the FWS on the Factory Floor using a C program, which is utilized to communicate the data to …


Performance Evaluation And Comparison Of Ordinary, Adaptive And Exhaustive Services In The Token Ring Network, Hong Wang May 1991

Performance Evaluation And Comparison Of Ordinary, Adaptive And Exhaustive Services In The Token Ring Network, Hong Wang

Theses

Ordinary service and exhaustive service are two major alternatives of scheduling policies considered in providing access to token ring networks. Results to date have shown that exhaustive service results in more delay to lightly loaded stations in asymmetric traffic while ordinary service wastes time in circulating the token after each transmission. This work presents a new token passing protocol, called adaptive service, in which the token holding time is dynamically changing; in this way, it provides a fair compromise between exhaustive and ordinary service. The simulation results show that in asymmetric traffic, adaptive service gives improvement on the local delay …


Image Enhancement And Analysis Of Leukocyte Adhesion, Yee-Ruh Lin May 1991

Image Enhancement And Analysis Of Leukocyte Adhesion, Yee-Ruh Lin

Theses

The image of leukocyte adhesion to microvascular walls in the isolated rat perfused heart model has been observed and processed. Some of the fluorescent labeled leukocytes are barely visible due to microscope focal plane and the motion of objects. The purpose of this thesis is to extract leukocyte from the image of the experimental data using image enhancement and analysis (segmentation) techniques and develop a program to handle automatically counting of leukocytes in a predefined scene.


Effect Of Shrinkage On The Design And Manufacture Of Plastic Parts In Injection Molding Using Cad/Cam Techniques, Deepak M. Shastri May 1991

Effect Of Shrinkage On The Design And Manufacture Of Plastic Parts In Injection Molding Using Cad/Cam Techniques, Deepak M. Shastri

Theses

Computer aided design software in injection molding has revolutionized injection molding in the design and manufacturing processes. Computer Aided Engineering can be applied to injection molding to increase the process efficiency, reduce part costs, and produce accurate parts in less time. The mold designer has many software programs to choose from to produce satisfactory mold designs from part geometries, and a correct selection can produce profitable results. A study of the need for and the scope of computers in injection molding is performed to evaluate the suitability of a CAE package by considering the value added to the parts using …


Implementation Of Automated Assembly, Kang H. Kong May 1991

Implementation Of Automated Assembly, Kang H. Kong

Theses

Research has shown that about 60 - 80% wealth producing activities is related to manufacturing in major industrial countries.

Increased competition in industry has resulted in a greater emphasis on using automation to improve productivity and quality and also to reduce cost.

Most of the manufacturing works such as machining, painting, storage, retrieval, inspection and transportation have changed to automation successfully, except assembly. Manual assembly is predominant over automatic assembly techniques due to inherent assembly problem and the fact that the assembly machines lack the innate intelligence of human operator and lack sufficient flexibility to changeover when product designs and …


Simulation Of Voice And Data Integration, Urmila S. Patel May 1991

Simulation Of Voice And Data Integration, Urmila S. Patel

Theses

A simulation model of integrated voice and data is developed. The data packets are transmitted during voice inactivity (i.e. silence duration). A statistical model of voice (talkspurt) and silence duration is generated. inter-arrival time between data packets is modeled using geometrical distribution. The data traffic statistics is simulated for a given voice activity model and various data packet arrival rates. Four important results are obtained by performing this simulation: 1. Average data packet delay versus arrival rate. 2. The optimal ratio of data packet arrival rate to average data packet delay. 3. Probability of wait time for various data packet …


Size Reduction Of Polymeric Particulates By Jet Milling, Cheng Hua May 1991

Size Reduction Of Polymeric Particulates By Jet Milling, Cheng Hua

Theses

A basic theory for the size reduction operation by jet milling has been developed.

Typical samples of feedstock have been analyzed using screen analysis to determine the initial distribution of polymeric particulate sizes prior to jet milling.

A statistical theory .was developed using probabilities to represent the likelihood that specific size reductions would occur. These probabilities include the effects of various equipment.

The theory was then used to predict the distribution of polymeric particulate sizes after jet milling. The agreement between the predictions and actual results was within 5 %.

Encouraged by the successful work of the simulation of the …


Design For Manufacturability, Kocherlakota Sreedhar May 1991

Design For Manufacturability, Kocherlakota Sreedhar

Theses

Design for Manufacturability represents a new awareness of the importance of design as the first manufacturing step. It recognizes that a company cannot meet all its objectives with isolated design and manufacturing operations. The Design for Manufacturability approach embodies certain underlying imperatives that help maintain communication between all components of the Manufacturing and Design system and permit flexibility to adopt and to modify design during each stage of the product realization. Design for Manufacturability cannot be bought or sold and it should be implemented by management. Complete support of management to the implementation is very important to the success of …


Eeg Data Compression, Yun-Chu Wu May 1991

Eeg Data Compression, Yun-Chu Wu

Theses

This paper presents two different ways to compress EEC data-direct data com pression and a data transformation technique. The Adaptive Delta modulation and Huffman coding are used in the former method to predict or interpolate the data. Linear orthognal transformation algorithms are used in the latter method to detect and reduce the redundancies of the data by analyzing the spectral and energy distribution. Each method is implemented by programming the computer. The experimental results of their efficiencies and errors with different requirements and under different situations are compared and discussed. By comparing the EEC data compression degree and normalized square …


Burn Wound Healing Evaluation By Infrared Imaging, Shang-Yuan Chen May 1991

Burn Wound Healing Evaluation By Infrared Imaging, Shang-Yuan Chen

Theses

Infrared imaging is a pictorial method of temperature representation. Its advantage in the treatment of burns is that it is a non-invasive, safe and reliable method for estimating the area, temperature and depth of burns. An Imaging Burn program was developed for comparing changes in burn area in response to treatment with time. The program proved itself capable of determining the surface area of simulated lesions on the skin of human volunteers to within an error of 1.6 percent. The size and temperature of burn lesions in patients was recorded. First degree burns were warmer than surrounding areas of normal …