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Theses/Dissertations

1992

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Full-Text Articles in Engineering

On Adaptive Censored Cfar Detection, Loizos Anastasiou Prastitis Dec 1992

On Adaptive Censored Cfar Detection, Loizos Anastasiou Prastitis

Dissertations

In an automatic radar detection system the received signal in every range resolution cell is compared with a threshold to test for the presence of a target. A Neyman-Pearson type test is used which maximizes the probability of detection for a fixed probability of false alarm. For the simple case where the noise is homogeneous a fixed threshold is chosen to achieve the designed constant false alarm rate (CFAR). In the more realistic case the noise background is non-stationary due to clutter and interference. In this situation, the threshold used for testing a particular cell is usually set adaptively using ...


Analysis Of A Band-Saw, Suat Ali Ozsoylu Dec 1992

Analysis Of A Band-Saw, Suat Ali Ozsoylu

Dissertations

The solution for the transverse oscillations of a band-saw is determined. Two different models are treated: a fourth-order model and a second-order model. The response characteristics for both models are determined using Laplace transformation. To obtain the inverse Laplace Transform for the fourth-order model, it was necessary to fmd the frequencies by applying the Extended Lanczos Method in order to overcome the problem for computer overflow.

The limits of stability for both models are studied by plotting the eigenvalues against changing parameter values. Conditions for the onset of divergence and flutter instabilities, which need to be taken into account in ...


Three Dimensional Magnetic Field Sensors And Array In Bicmos Technology, Bingda Wang Dec 1992

Three Dimensional Magnetic Field Sensors And Array In Bicmos Technology, Bingda Wang

Theses

This thesis presents new designs of three dimensional magnetic field sensors in BiCMOS technology. The detailed design of the merged structure device by common diffusion and the high gain transduction circuit are presented. The merged structure has the advantage of less area, less external contacts and less parasitic capacitance. Cross-sensitivity is also eliminated by employing the merged structure. Three active on-chip loads are introduced to improve the sensitivity. The SPICE simulation results show that when a relative change in current ΔI/I is 0.001, about 13.6 mV and 8.5mV can be detected at the output in X ...


Trouble Shooting In Plastic Injection Molding Machines, Zafar Kamal Dec 1992

Trouble Shooting In Plastic Injection Molding Machines, Zafar Kamal

Theses

The purpose of this thesis is to find the solution of those problems which occur during plastic injection molding process. Molding cycle problem analysis is an important field in plastic injection process. It is very necessary to catch the problems during operation. Therefore on the basis of research trouble shooting criteria is prepared.

Good quality control is an essential feature for finding any sort of fault. Quality control is associated with each and every step of operation to maintain the required shape and surface finishing.

Most of the molding problems are solved by varying the machine conditions and by changing ...


Simulation Study For The Effect Of Dependencies In Queueing Systems, Yitao Bai Dec 1992

Simulation Study For The Effect Of Dependencies In Queueing Systems, Yitao Bai

Theses

Few theoretical results have been obtained in the literature for the effects of dependencies between random variables on the performance of queueing systems. This thesis aims at investigating this issue via simulation. Several dependencies are studied in detail, including dependencies between interarrival times, between interarrival time and service time, between service times and dependencies between different stages in networks of queues. We define several classes of dependent random variables and study their correlation coefficients, then we apply them to single and multiple station service systems. Comparisons with the independent case, for which the explicit form solution are available, are made ...


Timed Petri Net Simulation Of Flexible Manufacturing Systems, Yan Chen Dec 1992

Timed Petri Net Simulation Of Flexible Manufacturing Systems, Yan Chen

Theses

Standard Petri nets have been used to model and analyze Flexible Manufacturing Systems. The timed Petri net, which can incorporate the time delay associated with manufacturing events, provides additional information about real time behavior of practical systems. The Timed Petri Net Simulation Tool, a highly interactive graphical tool, is applied to simulate the modeled flexible manufacturing systems. Timed Petri net models are experimented with. Machine utilization data and throughput are obtained. Analysis of the results shows that the system performance can be optimized by choosing proper parameters.


Analysis Of The Optimum Extraction System Design For The Separation And Purification Of Rare Earths, Kenneth Yeon-Kang Chan Dec 1992

Analysis Of The Optimum Extraction System Design For The Separation And Purification Of Rare Earths, Kenneth Yeon-Kang Chan

Dissertations

A mathematical model for the liquid-liquid equilibrium of the lanthanide and yttrium oxides in the nitric acid - water - tributyl phosphate (HNO3-H2O-TBP) two-phase system has been developed. This model is based on the interrelationships of chemical reactions, phase equilibrium, and material balance. The chemical reactions were modelled using experimentally derived empirical equations for components involved. The distribution coefficients of 16 rare earths which were experimentally determined. by UK Harwell Laboratory were used to evaluate the parameters of this equilibrium model. Once model parameters are determined, material balance for all species in the HNO3-H2O-TBP ...


Investigation Of Reactor Design Parameters Towards Optimizing Biodegradation Of Chlorophenols By Phanerochaete Chrysosporium, Nirupam Pal Dec 1992

Investigation Of Reactor Design Parameters Towards Optimizing Biodegradation Of Chlorophenols By Phanerochaete Chrysosporium, Nirupam Pal

Dissertations

The biodegradation of 2,4,6-trichlorophenol (246-TCP) and 2,4,5-trichiorophenol (245-TCP) by Phanerochaete chrysosporium was studied in batch and in continuous systems. Contrary to most of the previous reports from the literature, this study shows that degradation of both TCPs can occur in the absence of any measurable ligninase activity. The microorganism did not retain its degradative ability for more than about two weeks

In order to better understand the degradation process, the individual contributions of both the biomass and the extracellular proteins were studied separately. The results show that neither the biomass nor the extracellular proteins alone can ...


Study Of Surface Properties Produced By Magneto-Plasma On Nitriding For Improving Wear Resistance, I-Tsung Shih Dec 1992

Study Of Surface Properties Produced By Magneto-Plasma On Nitriding For Improving Wear Resistance, I-Tsung Shih

Dissertations

In this work a newly developed surface treatment process, Magneto-Plasma Ion Nitriding process, was developed and studied. This process was developed to increase durability and wear resistance of operational surfaces of different machine components.

In this study, orthogonal experimental analysis was used to develop, optimize, and select the process parameters. Coating layers were characterized and studied by using scanning electron microscopy(SEM), Auger electron spectroscopy(AES), and image analysis system. The influence of different process treatment parameters, such as temperature, nitrogen concentration, and magnetization, on the layers properties was studied. The mechanism of layer formation and bonding was proposed and ...


Kinematic Synthesis Of Adjustable Four-Bar Mechanisms For Multi-Phase Motion Generation, Shao Jie Wang Dec 1992

Kinematic Synthesis Of Adjustable Four-Bar Mechanisms For Multi-Phase Motion Generation, Shao Jie Wang

Dissertations

A four-bar linkage can satisfy up to five prescribed positions for the motion generation problem. The adjustable four-bar linkage, on the other hand, can satisfy more than five given positions by making some of the parameters adjustable.

Limited work had been done in the area of motion generation problems of kinematic synthesis of adjustable four-bar linkages until Wilhelm introduced the concept of multiple adjustments.

This study considers for the first time, the adjustment of a moving pivot, and the problems of three phases of motion. Various combinations of the number of prescribed positions for the motion generation problems are solved ...


Investigation Of The Consumer Electronics Bus, Jaesoo Yang Dec 1992

Investigation Of The Consumer Electronics Bus, Jaesoo Yang

Dissertations

The objectives of this dissertation are to investigate the performance of the Consumer Electronics Bus (CEBus) and to develop a theoretical formulation of the Carrier Sense Multiple Access with Contention Detection and Contention Resolution (CSMA/CDCR) with three priority classes protocol utilized by the CEBus

A new priority channel assigned multiple access with embedded priority resolution (PAMA/PR) theoretical model is formulated. It incorporates the main features of the CEBus with three priority classes. The analytical results for throughput and delay obtained by this formulation were compared to simulation experiments. A close agreement has been found thus validated both theory ...


Investigation Of The Striation Formation In The Course Of Abrasive Waterjet Cutting, Jo-Fei Chao Dec 1992

Investigation Of The Striation Formation In The Course Of Abrasive Waterjet Cutting, Jo-Fei Chao

Dissertations

The principal defect of the surfaces generated by abrasive waterjet machining is excessive waviness (striation). The existing theories of striation formation are not adequate to explain this phenomenon. The presented study is concerned with the development of an understanding of the mechanism of striation formation.

A spectral analysis of temporal process and spatial surface characteristics demonstrated that the striation is caused by nozzle vibration that is due to the conditions of the motion control of the nozzle. This enabled us to discover a means for improving the surface finish. From a study of the surface spectra, it was found that ...


Utilizing Instructional Design Constructs To Enhance Computer-Based Instruction In Air Traffic Controller Training, Theodore Scott Rhoads Dec 1992

Utilizing Instructional Design Constructs To Enhance Computer-Based Instruction In Air Traffic Controller Training, Theodore Scott Rhoads

Theses - Daytona Beach

This study demonstrates that a computer-based instructional design format is appropriate for novice air traffic control (ATC) training. The computer presents the student with small amounts of information in tutorial and drill and practice sequences that necessitate student interactivity. The student is then periodically audit tested to ascertain mastery of the subject matter. The result of these mid-lesson evaluations serve as a self-check so that the student can assess his/her progress in the learning cycle. The systematic design of instruction and interactive approach to learning, enhances student motivation, improves learning and retention, while placing the responsibility of achieving specific ...


Semiconductor P-N Junction Space Charge Region Capacitance, Mohammad Humayun Habib Dec 1992

Semiconductor P-N Junction Space Charge Region Capacitance, Mohammad Humayun Habib

Dissertations and Theses

The classical capacitance voltage characteristics based on the depletion approximation, is adequate at reverse bias, but introduces errors at high forward bias. Because of its inherent simplicity and compactness this classical depletion model is well studied and widely used in circuit simulators. In this work, a new model for the semiconductor space charge region (SCR) capacitance, based on physical justification, will be derived. This new model takes three input parameters, C0 , Vbi and m, thus eliminating the fitting parameter FC currently used in SPICE. This new model is applicable for any applied voltage and will be compared with the SCR ...


A Photometric Analysis Of Weapon Separation Characteristics, Douglas Paul Yurovich Dec 1992

A Photometric Analysis Of Weapon Separation Characteristics, Douglas Paul Yurovich

Masters Theses

This project attempted to implement a unique multi-camera photometric technology into the discipline of weapons separation testing from tactical jet aircraft.

This project was a U.S. Governmental, Department of Defense tasked affair, that utilized assets of the Naval Air Warfare Center Aircraft Division, Naval Air Station, Patuxent River, Maryland.

The methodology employed consisted of a standard lens calibration procedure; an airspace calibration procedure, that defined the zone for the activity of motion, and targeting of the aircraft and specific store.

With filmed flight test data in hand, the data was digitized through a motion sensor and stored as computer ...


Conceptual Design Of The Modular Transuranic Shipping Cask Mts-54, Vojislav Banjac Dec 1992

Conceptual Design Of The Modular Transuranic Shipping Cask Mts-54, Vojislav Banjac

Nuclear Engineering ETDs

The storage, transportation, and disposal of radioactive waste has become a problem of immense proportions in the United States. This Thesis focuses on the transportation of defense transuranic (TRU) waste to the Waste Isolation Pilot Plant (WIPP) repository near Carlsbad, New Mexico. The objective of the cask conceptual design was based on the following:

  • Taking into account the latest available data on TRU waste drum mass, investigate the possibility of increased drum capacity per shipment over the current design;
  • Present a new TRU cask design with increased drum capacity and the potential for transporting both Contact-handled (CH and Remote-handled (RH ...


Development And Analysis Of Non-Delay-Line Constant-Fraction Discriminator Timing Circuits, Including A Fully-Monolithic Cmos Implementation, David Martin Binkley Dec 1992

Development And Analysis Of Non-Delay-Line Constant-Fraction Discriminator Timing Circuits, Including A Fully-Monolithic Cmos Implementation, David Martin Binkley

Doctoral Dissertations

A constant-fraction discriminator (CFD) is a time pick-off circuit providing time derivation that is insensitive to input-signal amplitude and, in some cases, input-signal rise time. CFD time pick-off circuits are useful in Positron Emission Tomography (PET) systems where Bismuth Germanate (BGO)/photomultiplier scintillation detectors detect coincident, 511-keV annihilation gamma rays.

Time walk and noise-induced timing jitter in time pick-off circuits are discussed along with optimal and sub-optimal timing filters designed to minimize timing jitter. Additionally, the effects of scintillation-detector statistics on timing performance are discussed, and Monte Carlo analysis is developed to provide estimated timing and energy spectra for selected ...


Laser Doppler Velocimetry Research Of The Blowby Gas Characteristics In An Internal Combustion Engine, Mark Kevin Coffill Dec 1992

Laser Doppler Velocimetry Research Of The Blowby Gas Characteristics In An Internal Combustion Engine, Mark Kevin Coffill

Master's Theses

The project was designed to measure a reciprocating engine fluid flow (blowby gases past the piston rings) using a laser doppler velocimeter (LDV). Blowby gases were obtained by introducing compressed air into an engine cylinder (piston held at TDC) to simulate engine combustion pressures. Beginning the proposed research included starting an LDV/reciprocating engine laboratory at Western Michigan University and determining the limits of the measurement devices (LDV system in particular).

The limitations which were found in the LDV system only allowed for limited results of in cylinder optical measurements. The results obtained were for cylinder pressures below 0.6 ...


An Integrated Simulation Model Development Environment For Slam Ii Using Object-Oriented Paradigm, Rizvan Erol Dec 1992

An Integrated Simulation Model Development Environment For Slam Ii Using Object-Oriented Paradigm, Rizvan Erol

Master's Theses

An integrated simulation model development environment was implemented to assist the modeler by automating certain activities of simulation modeling. The system included interactive model definition, experimental design, automatic simulation program generation in SLAM II. Object-oriented paradigm at software development stage was extensively used to conceptualize the structure, and rules of the SLAM II language in order to generate efficient, and modular program code. The present system targeted modeling of various probabilistic inventory control system problems. The remarkable advantages of the system were rapid model development time, and achieving reliable program code without requiring any knowledge in SLAM II. Object-oriented programming ...


A Study Of The Effects Of Polyacrylates On Water Retention And Binder Migration Tendencies Of Coatings, Wichan Charoenkitsupat Dec 1992

A Study Of The Effects Of Polyacrylates On Water Retention And Binder Migration Tendencies Of Coatings, Wichan Charoenkitsupat

Master's Theses

Five commercial polyacrylate samples were used to study their effects on viscosity, water holding, and binder migration under non-pressure conditions. The polyacrylates used were different in acid level, degree of crosslinking, and type of polymer (copolymer and terpolymer). A series of coatings was prepared using a number two clay and three styrene-butadiene latexes of similar particle size and T⋁g but different degrees of carboxylation, then the polyacrylates were added at several levels. The coatings were evaluated for rheological properties, water loss rate and binder migration. The results show that with increasing amounts of polyacrylates, the viscosity increased and the ...


A Computer Simulation Of The Rotary Vacuum Filter Brown Stock Washing System Using Distribution Sampling, Edison G. Yiu Dec 1992

A Computer Simulation Of The Rotary Vacuum Filter Brown Stock Washing System Using Distribution Sampling, Edison G. Yiu

Master's Theses

A probabilistic model was utilized to simulate the brown stock washing system's error due to process variability and measurement noise. Mass balances of the washing system were performed using distribution sampling. This model relies on a nonlinear relationship between displacement and dilution, which permitted the generation of displacement ratio based upon wash liquor ratio. Experimental trials were performed on a pilotscale rotary vacuum single-stage washer. Nonlinear first-order relationship appears to characterize a pilotscale washer adequately. Differences were observed between the means and standard deviations of the measured results compared to the simulation output. Future work is needed to identify ...


A Study Of The Effects Of Pigment Size And Shape On Binder Migration, Hee Jong Yang Dec 1992

A Study Of The Effects Of Pigment Size And Shape On Binder Migration, Hee Jong Yang

Master's Theses

The effects of pigment size and shape on coating structure and binder migration has been investigated. Clays and ground calcium carbonates of different particle size distributions were used in coatings with 15 pph SB latex.

Coatings were applied to Mylar and a special Tyvek using a wire wound rod. The coatings were dried slowly under ambient conditions, and using hot air immediately or after having been allowed to reach immobilization through penetration into the Tyvek. The dried coatings were evaluated for water holding, relative pore size and migration using the UV technique to measure the increase in SB latex at ...


Thermally Induced Vibration Of A Cross-Ply Laminated Plate With Hygrothermal Effects (Exact Solution), Stephen Jerry Maerz Dec 1992

Thermally Induced Vibration Of A Cross-Ply Laminated Plate With Hygrothermal Effects (Exact Solution), Stephen Jerry Maerz

Theses - Daytona Beach

Of increasing importance in structural design is the use of fiber-reinforced polymeric composite material, notably in advanced aircraft and projectiles. These applications expose the materials to varied environmental conditions, therefore the material performance under these conditions is of great interest. One aspect of this is the solution of the dynamic response of a composite structure under elevated temperature and moisture conditions. An exact solution is formulated which describes the hygrothermal effects due to heating and moisture diffusion on one surface of a symmetric cross-ply plate made of AS/3501 graphite epoxy with simply-supported boundary conditions.


Isolating Failure Mechanisms In A Fiberglass/Epoxy Tensile Test Specimen Using Acoustic Emission Signal Parameters, Michael Kouvarakos Dec 1992

Isolating Failure Mechanisms In A Fiberglass/Epoxy Tensile Test Specimen Using Acoustic Emission Signal Parameters, Michael Kouvarakos

Theses - Daytona Beach

This study used acoustic emission (AE) signal parameters to isolate the failure mechanisms in a 0° unidirectional, fiberglass/epoxy tensile test specimen. Since several failure mechanisms were known to be present, the lack of any distinctly identifiable bands in the original amplitude distribution indicated that there was considerable overlap between the AE signals of the various failure mechanisms. In order to separate the amplitude bands associated with each mechanism, it was necessary to sort on the duration of the AE signal. Two additional plots, counts versus amplitude and hits versus counts, were used to verify that the amplitude distributions were ...


A Study On Radical Scavenging And Magnetic Resonance Imaging Characteristics Of Stable Radical Nitroxides, Shiey-Shiun Horng Oct 1992

A Study On Radical Scavenging And Magnetic Resonance Imaging Characteristics Of Stable Radical Nitroxides, Shiey-Shiun Horng

Dissertations

Several nitroxides have been prepared for study of their image enhancement capability. These nitroxides contain different nitroxyl moieties within one molecule. On MRI examination for the nitroxides prepared, TEMPO and HPTPO are better due to their better water solubility, even though some of the others have more nitroxyl centers available. The intensity response is linear with respect to concentration in the range studied in most of the cases except for HPTPO, whose intensity finally reaches maximum when its concentration is higher than 10 mM.

Three sources of biomass, namely, liver microsomes, whole-cell yeast and a bacterial activated sludge consortium, have ...


Fabrication And Characterization Of Gated Silicon Field Emission Micro Triodes, Nanchou Liu Oct 1992

Fabrication And Characterization Of Gated Silicon Field Emission Micro Triodes, Nanchou Liu

Dissertations

This dissertation describes the fabrication technology and characterization of a gated silicon field emission micro triode that is a novel electron tunneling device for generating electron emission into a vacuum. Conic (point) and wedge field emitter structures with nm-scale radii were fabricated in silicon and GaAs by etching, MOCVD and dry oxidation. A new self-aligned process was developed for fabrication of vertical field emission triodes. This process allows control of gate opening to less than 0.5 μm diameter without the need of electron-beam writing. It also provides a planar gate electrode and a thick dielectric layer for reduction of ...


Design For Productivity Using Gd&T, Srihari G. Acharya Oct 1992

Design For Productivity Using Gd&T, Srihari G. Acharya

Theses

No abstract provided.


Errors In Constant-Velocity Shaft Couplings, Philip M. Remington Oct 1992

Errors In Constant-Velocity Shaft Couplings, Philip M. Remington

Theses

A Multiloop spatial system of rotations is used to represent a shaft coupling, allowing a transmission plane which may deviate from the plane of symmetry to be specified. The plane of transmission, for intersecting input and output shaft axes, is the locus of intersections of screw axes that compose the system. By prescribing the transmission plane outside of the plane of symmetry (commonly called the "homokinetic plane" or "bisecting plane") to pecified orientations, a phase shift between the input and output shaft rotational displacements will he quantified. The rotational phase shift between the input and output shafts can be evaluated ...


Mathematical Model And Simulation Of The Progression Of Cutaneous T-Cell Lymphoma, Maria L. Agostinho Oct 1992

Mathematical Model And Simulation Of The Progression Of Cutaneous T-Cell Lymphoma, Maria L. Agostinho

Theses

A simple mathematical model and simulation of the progression of cancer with particular emphasis on Cutaneous T Cell Lymphoma was investigated. The mathematical model consists of a set of differential equations that first satisfies the homeostasis levels of the different components present and second predicts the dynamics during a diseased or unhealthy condition. The simulation was done using a FORTRAN program for integrating the differential equations.

Simulation of the immune system is important in evaluating the usefulness of particular sorts of biologically targeted therapies and in selecting the most promising treatment strategies for clinical trials. In particular, the effects of ...


Quantitative Assessment Of Myocardial Oxygen Supply And Demand Using A Dynamic Model Of The Cardiovascular System, Badrinath R. Puranic Oct 1992

Quantitative Assessment Of Myocardial Oxygen Supply And Demand Using A Dynamic Model Of The Cardiovascular System, Badrinath R. Puranic

Theses

A quantitative understanding of the changes in coronary, pulmonary and systemic hemodynamic variables and their effect on myocardial supply and demand is important to the better management of anesthetic care of patients with impaired cardiac function. Animal studies have identified those hemodynamic factors that play an important role in determining the balance between oxygen supply and demand for the myocardium. These include myocardial contractility, left ventricular end-diastolic volume, systemic arterial pressure, systemic vascular resistance, and heart rate. The interactions of these factors are complex and their combined effects on myocardial oxygen supply and demand are difficult to predict a priori ...