Engineering Commons^™

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 …

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 a mathematical …

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 …

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 and simulation …

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 …

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 completely degrade 246-TCP, but …

Reduction Of Acoustic Feedback Oscillations By Use Of Spectrum Shifting, Youssef Abdelilah

Theses

The problem of whistling noise or self-oscillation in public address systems operating in closed halls or rooms can be very disturbing to the listeners. This noise is sustained when the positive acoustic feedback, of the public address-room system, meets the oscillation criteria. This feedback system results from the acoustic sound signal reflected off the room walls and any other obstacles in the room, originating from the public address speakers and then re-entering the microphone.

When all of the audio signal components entering the public address system are shifted by a frequency increment Δf of 6 Hz, an increase of 5 …

Evaluation Of Truck Restrictions Using Simulation, Shaikh Mohamed Arif

Theses

Traffic congestion is a major problem in many central business districts. Many strategies have been proposed and implemented to solve or alleviate this problem. One of the most common strategies is to impose travel restrictions on the movement of trucks, without reviewing the economic consequences of goods movement restrictions on shippers, customers and on the overall business activity of the area.

This research examines the effect of various truck restrictive policies on the cost of urban goods movement, using the central business district of Manhattan as a case study. Computer simulation techniques are used to evaluate several scenarios under different …

Pressure Swing Absorption-Based Separation Of A Gas Mixture, Syamalendu Bhaumik

Theses

In this study, separation of a gas mixture was investigated using the novel concept of pressure swing absorption in a stationary absorbent liquid. The best features of pressure swing adsorption, gas liquid scrubbing and hollow fiber based membrane processes were incorporated to develop the process.

A well-packed microporous hydrophobic hollow fiber module was used to achieve absorption of a gas at a high pressure into a liquid during a certain part of the cycle followed by desorption of the gas from the liquid in the other part of the cycle. The device has a very high interfacial area per unit …

Behavior Of R/C Columns Under Nonproportional Variations In Axial And Lateral Loads, Kaniz Fatema Ahsan

Theses

The study on the behavior of reinforced concrete columns subjected to the motion of earthquake suggests that the structure may experience nonproportional variations in axial and lateral forces. In order to assess the capacity of a reinforced concrete structure under nonproportional loadings, an analytical model is developed using the fiber modeling technique.

The method is based on detailed analytical description of the geometry and material properties used in evaluating the behavior of the critical regions rather than a simplified and predefined set of hysteresis rules. The present study has two principal components of investigation. First, the analyses are done at …

Measures For Estimating The Need For Flexibility In A Manufacturing Facility, Raghu Chilukuri

Theses

Manufacturing technology is in the midst of on-going developments stemming from rapid improvements in machine tools, computers and robots. These developments present engineers with greater challenges and opportunities in designing more complex and productive systems. The concept of flexibility was defined by authors like Jaikumar, Son & Park, and Buzacott. The various challenges can be partly over come by building flexibility into the various systems. Various operational or raw measures are described as they help managers to understand the kind and extent of flexibility embedded in their production process and allow them to make informal judgement on new equipment.

Various …

An Improved Human Gait Model Incorporating The Effects Of Muscle Activity And Joint Friction, Tae Ho Choi

Theses

In designing an artificial leg for an amputee, it is important to find those underlying principles which determine the normal human gait. For this purpose we have developed a model of human walking, in which it is possible to predict an optimal gait at any given speed of walking based on the principle of minimum mechanical energy consumption.

Our model is an extension of the model proposed by Mochon and McMahon (1980). Their model assumes that during the swing phase of walking mechanical energy is conserved. Non-conservative forces due to muscle activity are assumed to occur during the double support …

The Permeability Of Hot Mix Asphalt Concrete With Petroleum Contaminated Soils, Kuen-Yuan Chuang

Theses

It is estimated by the United States Environmental Protection Agency (USEPA) that there are 2 to 3.5 million underground storage tanks (USTs) throughout the nation and about 25% of these tanks are leaking. The leakage of petroleum or other organic material presents serious environmental problem due to the uncontrolled release of petroleum products to ground water. Many new techniques have developed to reuse these petroleum contaminated soils generated from sites containing leaking USTs. One such soil reuse method available since 1985 is the use of petroleum contaminated soils in the production of hot mix asphalt.

The stability, durability, and hydraulic …

Entrance Effects For Short Catalytic Combustion Monoliths, Dong Dai

Theses

Catalytic combustion/incineration is becoming increasingly important in modern industrial processes. This thesis work investigates the importance of heat and mass transfer entrance effects in short catalytic combustion monoliths, and includes these effects in an engineering model. Consideration is limited to laminar-flow heat and mass transfer in a circular tube, in which Prandtl number is close to unity, as is the case for air. Thermal, mass and velocity boundary layer growths are considered with inlet conditions assumed uniform at a monolith bed entrance. Conservation equations are solved assuming laminar, steady-state flow, with constant wall temperature, and negligible axial diffusion of heat …

A Planning Model For Intermodal Auto-Rail Transportation Assignment, Daniel Disario

Theses

This thesis presents a planning model for assigning trips in a corridor served by highways and commuter rail. The underlying assumption is that commuters will choose a mode (or a combination of modes) connecting the origin and destination in a way that will either minimize their individual travel times and costs (the user equilibrium principle) or minimize total system travel time and cost (system optimal principle). The model is structured as a mathematical program with a non-linear objective function and linear constraints.

The model was applied to a case study of the Raritan Valley Corridor located in Northern New Jersey. …

Dynamics Of Blood Coagulation, Jie Gao

Theses

In this paper we present a new method to analyze whole blood coagulation dynamics. Using a PC-286 computer equipped with a DASH-16 AID board.

The row data from a SONOCLOT analyzer is amplified and digitized on the DASH-16 A/D board and stored in the PC-286 hard disk. The data is filtered through a digital Butterworth filter. The filtered data is then fit to mathematical relationship by the least square method. The coefficients which define the mathematical relationships are used to identify blood specimens with normal coagulation dynamics as distinguished from specimens with abnormal dynamics.

The digital filter and curve-fitting routine …

Studies Of Wet Thermal Oxidation Of Silicon And Porous Silicon, Nilesh A. Gharia

Theses

Wet Thermal Oxidation of Silicon in VLSI is an extremely important step in the formation of field oxides. Understanding oxidation kinetics is critical for process reproducibility. The present study aims at gaining an insight into the oxidation kinetics through large experimental data at process temperatures of 800°C, 900°C, 1000°C and 1100°C with a bubbler temperature of 98°C. Oxides with thicknesses ranging from 100A to 7000A have been grown. Rate constants are obtained for the growth kinetics. Extensive characterization studies have been performed on MOS structures produced after wet oxidation.

In addition, porous silicon which assumes a growing significance in the …

Microwave Gaas Mesfet Nonlinearity And Large-Signal Modeling, Yan He

Theses

The nonlinearity analysis for a 0.5μm gate length microwave GaAs metal-semiconductor field-effect transistor (MESFET) by HP85150B Microwave Design System was investigated. The analysis starts with the construction of a large-signal MESFET equivalent circuit model. This model consists of bias dependent elements that were extracted by the optimization of DC and small-signal S-parameter measurement data. The details on this construction procedure are included in this work. The MESFET third-order intermodulation distortion was then simulated by HP85150B Microwave Design System. Reasonable agreement was obtained between simulation and measurement results. Microwave GaAs MESFET nonlinearity principles and large-signal modeling technique review are also presented. …

Partial Vlsi Implementation Of The Architecture For Reusable Components (Arc), Deepak Kakadasam

Theses

This work describes a novel VLSI implementation of the Architecture for Reusable Components (ARC) processor, using Hardware Description Language (HDL). The main goal here is to achieve efficient execution of reusable software through proper hardware support. This involves the hard wired implementation of each instruction designed for the ARC processor.

Instructions are broken down into their logical functions, then modeled and simulated through the hierarchical design methods that HDL offers. The structural model of the processor has been developed and simulated. The purpose here has been to begin work on the design and implementation of the ARC processor.

The instructions …

Performance Analysis Of Pyramid Mapping Algorithms For The Hypercube, Jing-Chiou Liou

Theses

Comparative performance analysis of algorithms that map pyramids and multilevel structures onto the hypercube are presented. The pyramid structure is appropriate for low-level and intermediate-level computer vision algorithms. It is not only efficient for the support of both local and global operations but also capable of supporting the implementation of multilevel solvers. Nevertheless, pyramids lack the capability of efficient implementation of the majority of scientific algorithms and their cost may become unacceptably high. On a different horizon, hypercube machines have widely been used in the field of parallel computing due to their small diameter, high degree of fault tolerance, and …

Application Of Imaging Pyrometry For Remote Temperature Measurements, Michael B. Kaplinsky

Theses

The radiometric model of an IR image sensor has been developed. Based on this model, the application of imaging pyrometry to remote temperature measurements has been investigated. This analysis provides the estimation of temperature accuracy achievable by imaging pyrometry in conjunction with a number of radiometric methods. The detection of radiation emitted across the full spectral bandwidth of the imager as well as utilization of narrow-passband filters was analyzed for a target with known emissivity.

The methods of two-wavelength ratio radiometry and multi-wavelength radiometry were considered for the targets with unknown emissivity. The optimal selection of the wavelengths for the …

Stepwise Reduction And Approximation Method For Performance Analysis Of Generalized Stochastic Petri Nets, Jinming Ma

Theses

This thesis delves into the performance analysis of generalized stochastic Petri net (GSPN) model by using an approximation method: the Stepwise Reduction and Approximation (SRA) Method. The key point is that we are able to analyze a subnet in isolation by keeping its token flow direction and its sub-throughput equivalent with all the possible tokens entering into the subnet. The thesis first defines various kinds of potentially reducible subnets, subnet selection rules, approximation subnet construction rules, and reduction evaluation rules. Then corresponding to the possible subnets, the approximation method is used stepwisely until the interested measures are found with the …

Synthesis And Characterization Of Lpcvd Boron Nitride Films For X-Ray Lithography, Wen-Pin Kuo

Theses

Boron nitride thin films were deposited on silicon and fused quartz substrates using ammonia and the liquid precursor borane-triethylamine complex (TEAB) by low pressure chemical vapor deposition over a temperature range of 300-850°C, a pressure range of 0.21-0.6 torr, and an ammonia flow rate range of 0-740 sccm. An increased in the nitrogen content in the film due to the addition of ammonia flow resulted in a pronounced improvement in the optical transmission, an increase in the film uniformity and a decrease in the depletion effect. IR spectra of the films showed an asymmetrical wide band centered around 1400 cm …

Modal Control Of Flexible Beam Using Smart Mateirals, Sujata Mallepalle

Theses

In this work, the dynamics and control aspects of a vibrating flexible beam using modal analysis are studied. To damp the vibrations of the system, the vibrations of each mode has to he controlled, which can he done if we know the individual mode shape. and the resonance frequency. These quantities can be derived mathematically or measured experimentally with a spectrum analyzer. Individual modal velocities can be computed by integration of the product of beam velocity and the mode shape, over the interval of beam length. The integration is carried out using numerical methods. The necessary discrete ordinates are obtained …

A Review Of Energy Storing Prosthetic Feet And Computer Aided Structural Optimization Of A Below-Knee Prosthesis, Poonam Gope Lalwani

Theses

Because people with physical disabilities have shown an interest in participation in sports, a new class of prosthetic feet known as "energy storing prosthetic feet" has been developed. These new developments in prosthetic foot design utilize energy storage and return to improve ambulation. This thesis reviews the design, materials, advantages and disadvantages of various energy storing prosthetic feet. Research studies, comparing gait in below-knee amputees using different prosthetic designs, can be applied to the design of prosthetic feet that are lighter, stronger and more reliable. Comparisions among these feet are reviewed in the context of functional capability and patient satisfaction. …

Optical Flow Determination And Motion Analysis, Qian Wang

Theses

Optical flow, also known as image flow, is of fundamental importance in the processing of image sequences. Various approaches to determine optical flow have been proposed --- others continue to appear. Using several sets of real image sequences, here, the results of three different approaches to the the determination of optical flow are reported, the approaches are the Gradient-based approach, the Correlation-based approach and the Correlation-feedback approach. The comparisons are primarily empirical, and they show that the performance of these different algorithms differs significantly among the different image sequences, indicating that there does not exists one superior algorithm which could …

Microstructural Investigation Of Surface Coating Developed By Electro-Spark Deposition Technology, Tianzong Xu

Theses

Electro-spark deposition (ESD) is a pulsed-spark micro-welding process using an electrode to apply a fused, metallurgically bonded coating with an extremely low heat input so as to eliminate thermal distortion or changes in metallurgical structure of the substrate. The deposited surface achieves an exceptionally fine-grained, homogeneous coating that may approach as amorphous structure which is believed to contribute to good wear and corrosion resistance.

In this research, an optical image analysis system, scanning electron microscope with computerized energy dispersive spectrometer, microhardness testing system and computerized surfanalyzer were employed to investigate the microstructure and properties of achieved surface coatings.

As the …

A Programmable Integrated Power Supply For The Electrostatic-Drive Micromotor, Chao Ye

Theses

A 6-phase bipolarized, high-voltage power supply with rectangular pulse shape has been designed to study the special operational characteristics of various electrostatic-drive micromotors. In particular the design powers the variable-capacitance side-drive micromotor. This power supply provides variable frequency, variable voltage, and variable duty-cycle control. Simulation has been used extensively in the design and design verification.

The bipolarization (dual voltage polarity) of each pair of the phases reduces physical clamping of the rotor to the electrical shield beneath it. Thus, bipolarization of the voltage supplied to the stator nodes reduces charge build-up on the rotor.

The output frequency range varying from …

Fingerprint Pattern Recognition For Medical Uses, Feng You

Theses

The purpose of my research is to provide a method to automatically classify fingerprints into three subgroups: whorl, loop and arch, which can help medical scientists to study the relationship between fingerprint patterns and medical disorders. In the research, two different kinds of approaches were developed. The first one is performing pattern recognition in the frequency domain, which uses the feature of Fourier spectrum. That is, prominent peaks in the spectrum give the principal direction of fingerprint patterns. Using the above feature, we can obtain the principal direction of every subregion, after which the pattern of the whole image can …

A Study Of Pulsation Of Chest Wall Using Microwave Interferometer, Paul Zeno

Theses

The microwave interferometer is utilized to pick up vibrations of the anterior chest wall produced by the cardiac activity. The objective of this project is to find the causes of different peaks in the output of the microwave interferometer. The output of the microwave interferometer is recorded simultaneously with EKG and jugular pressure pulses. Eighteen subjects had their mechanical vibrations of the chest wall, EKG and jugular pressure pulses recorded. The processed interferometer data, when compared with EKG and jugular pressure pulses appear to have a close relation to the mechanical events in the cardiac cycle. Four peaks in the …