Engineering Commons^™

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 …

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. …

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 …

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. …

Modification Of Wear Testing Machine And Study Of Wear Resistance, Ning Li

Theses

In this work a modification of a wear testing machine has been done by designing a new loading mechanism and redesigning different components for a new roller-on-roller wear testing machine. A new loading mechanism containing gearbox frame and load cell assembly have been designed, manufactured and assembled. A pusher of the pushing mechanism is redesigned for better durability. Existing bearing support was redesigned and replaced. All new units of the wear testing machine were lined up and assembled with the machine. Finite element stress analysis for designed frame in the load mechanism was performed by using the Integrate Design Engineering …

A Direct Method For Surface Structure Recovering Based On Uoff, Ping Lin

Theses

The unified optical flow field (UOFF) theory which can be used for estimating motion and recovering surface structure was recently established in [9, 10]. The direct method developed in [2, 3, 4, 6, 7] does not need to explicitly solve the optical flow field and to find feature correspondence. Based on the UOFF, a direct method in space domain is developed to reconstruct the curved surface structure characterized by an Nth degree polynomial equation from a pair of stereo images. The initial work on this new method was reported in [8, 11].

In this study, I basically work on simulation …

Development Of A Composite User Equilibrium And System Optimization Assignment Model, Kimberly M. Stump

Theses

The Urban Transportation Modeling System (UTMS) is a set of procedures used by transportation planners to predict the volume of traffic that will flow through a network, and how the traffic is routed. This paper will focus on the final component of UTMS, traffic assignment, which assigns the traffic flows to actual routes in the network.

In this paper, two composite models which model both User Equilibrium and System Optimal assignments are presented. The composite models are solved using the GAMS (General Algebraic Modeling System) software, a powerful mathematical programming tool. The first model was based on Beckman's Formulation, (Beckman, …

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 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 …

The Thermal Model Of The Rat Under Hemorrhagic Shock Hypothermia With Microwave Intervention, Liu Zhe

Theses

A whole body thermal model simulating heat distribution and temperature regulation in rats during hemorrhagic shock and during post-shock microwave core rewarming period was developed. An electrical circuit was used to simulate the thermal system and a software named PSpice? was used to analyze the circuit. The temperature regulation as the result of the simulation is demonstrated to match the measured temperature histories of rats in hemorrhagic shock and the microwave rewarming experiment.

The blood pressure drop and cardiac output decrease were considered in the simulation and the so called "set point temperature" was investigated in the model. Linear decrease …

Computer Aided Finite Element Stress Analysis Of A Three Dimension Mandibular Bone Model Using I-Deas Software, Yixiong Xu

Theses

A three dimensional model of half of the mandibular bone, with 487 tetrahedra elements and 1,047 nodes, is established and analyzed by means of I-DEAS software. The masseter muscle is assumed to be 15° deviation from y-axis, and the Umetani boundary conditions are allowed to be varied. A 337 lb force was applied along the midline of the mandible to simulate a trauma force caused by the auto accident. The maximum principal stress is 18,400 psi and the minimum principal stress is -1,340 psi. Depending on the experimental results of dispalcement and maximum principal stress, the conclusions are drawn: 1) …

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 …

Development Of A Model For An Objective Minimum Resolvable Temperature Difference Characterization Of An Infrared Camera, Christine Issa Mourad

Theses

The parameter almost universally adopted by the infrared community for describing the overall performance of a thermal imaging camera is the minimum resolvable temperature difference. Unfortunately, this criterion is subjectively determined by a group of observers and as a consequence significantly varying results can be obtained at different times. This project describes work on an approach which ultimately aims to replace the observers by a computer-aided installation that simulates the human process by which the MRTD is estimated. The simulation is based on a direct measurement of signal to noise ratio in the image of the target and a determination …

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 …

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. …

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 …

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 …

Forward Kinematics Solution Of A Special Class Of General Stewart Platforms, Jian Li

Theses

A Stewart platform is a fully parallel, six-degree-of-freedom manipulator mechanism. A platform manipulator has a fixed platform acting as base, a mobile platform on which end-effector is mounted, and in-parallel kinematics chains (legs) between the two platforms. Although some direct position kinematics solutions for Stewart platforms of simplified geometry have been represented, to the best of our knowledge, no close-form direct kinematics solution for the general Stewart platform is available yet.

A common feature of six-degree-of-freedom Stewart platform of simplified geometry is the use of pairs of concentric ball joints. Due to inevitable manufacturing and assembly errors, practically there are …

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 …

Reverse Engineering : An Evaluation Of Contact Technology And Application In Manufacturing Systems, Shailesh V. Jadhav

Theses

There are many instances where one-of-a-kind parts, such as prototypes or custom-built parts, need to be reproduced. When a Computer Aided Design (CAD) of an existing part is not available, reverse engineering is involved in recreation of such part. Currently, geometric measurements from the surface of a prototype are extracted manually and sent to a CAD system. It is typically time consuming, tedious, and potentially a source of error. This study outlines a methodology, for the development of a CAD model, rapid prototype, and subsequently manufacturing of the part. The method developed uses a contact technique to extract 2-D or …

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 …

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 …

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 …

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(or Y) and Z directions, …