Engineering Commons^™

A Three-Dimensional Finite Element Stress Analysis Of Interface Conditions In Porous Coated Hip Prosthesis, Siu-For Yau

Theses

A three-dimensional finite element model of a collar-type hip stem and both the cortical and cancellous bones is used to investigate the stress distributions on an implanted femoral stem, adjacent bone, and specifically at the bone/implant interface for various amounts of porous coating and different stem materials. The finite element model consists of 909 nodes comprising 536 linear eight-node solid brick elements and 176 two-node interface elements. The finite element analysis code employed is SUPERTAB from SDRC. The interface elements consist of coincident-node spring elements and gap elements which model the rigidly bonded and loose interfaces respectively. Local coordinate systems …

Mobile Manipulator Path Planning By A Genetic Algorithm, Min Zhao

Theses

The thesis addresses the path planning problem for a mobile manipulator system which is used to perform a sequence of tasks specified by locations and minimum oriented force capabilities. The problem is to find an optimal sequence of base positions and manipulator configurations for performing a sequence of tasks given a series of task specifications. The formulation of the problem is nonlinear. The feasible regions for the problem are nonconvex and unconnected. Genetic algorithms applied to such problems appear to be very promising while traditional optimization methods cause difficulties. Computer simulation is carried out on a three degrees-of-freedom manipulator mounted …

Adaptive Filter Application In Fetal Electrocardiography, Xueqiang Zhou

Theses

A hybrid adaptive algorithm for cancelling the maternal electrocardiography (MECG) component in abdominal fetal electrocardiography(FECG) is described. This algo rithm combines the advantages of the orthogonal algorithm which was developed by Reichert(1977) and the multiple reference noise cancelling adaptive algorithm which was developed by Widrow(1975).

The simulating experiment was taken to test all of these three algorithms. It demonstrated that all these three algorithms can cancel the abdominal component of the maternal ECG with three limb lead ECG signals. and the hybrid algorithm is at least as effective as each other algorithm alone. In this experiment, the abdominal ECG signal …

Measurement Of The Electrical And Optical Properties Of Thermid Polymide, Zhixiong Zhu

Theses

Electrical and optical properties of spin-coated THERMID polyimide EL-5010 have been studied and evaluated in this thesis. The D.C. bulk resistivities of 0.96^-2.56 μm thick samples were measured to be 10¹⁶ Ω-cm over the 27-160°C range using a test system consisting of Keithley 236 Source-Measure Unit. The bulk resistivity decreased to 2 x 10¹⁴Ω-cm at 200?C. The surface resistivity, 10¹⁵Ω/0 , and breakdown voltage, 350 V/pm, were also measured. The fixed charge concentration and mobile ion concentration in the THERMID polyimide EL-5010 insulator of a MIS capacitor structure were measured using a high …

The Performance Evaluation Of A New Neural Network Based Traffic Management Scheme For A Satellite Communication Network, Dequan Liu

Theses

The thesis describes a new neural network based traffic management scheme for a satellite communication network. The scheme consists of two levels of management. The front end of the scheme is a derivation of the Kohonen's self-organization model to configure maps for the satellite communication network dynamically, The model consists of three stages. The first stage is the pattern recognition task which selects an exemplar map that best meets the current network requirements. The second stage analyzes the discrepancy between the chosen exemplar map and the state of the network, and adaptively modifying the chosen exemplar map to conform closely …

Mobile Robot Path Planning Based On Hierarchical Hexagonal Decomposition, Dan Zheng

Theses

In this thesis, a new algorithm based on hierarchical cell decomposition and artificial potential field is developed to solve the find-path problem for a mobile robot. The basic cell structure used for decomposition is a hexagon. The artificial potential field is based on an attractive force from the goal position and repelling forces from the obstacles. Computer simulations of the algorithm for various obstacle scenarios are also presented.

Oscillatory Potentials Model And Parameter Identification, Huizhong Pan

Theses

Two mathematicals model are presented for the oscillatory potentials of the electroretinogram. These models represent the oscillatory potential in terms of sets of parameters whose values may provide information of diagnostic value.

The test setup and protocol for obtaining the oscillatory potentials are described, as well as the data processing including acquisition up to identification of the model parameters.

Data from eight subjects, five normals and three diabetics, were used to evaluate the two models. These preliminary test results show a marked difference in the values of some of the model parameters between normals and diabetics.

Studies Of Electrical Properties Of Sio2 /Inp System, Milind S. Patel

Theses

Analyses of Electrical characteristics, of TilAu/SiO₂1InP structures, are presented here. The (MIS) Metal-Insulator- Semiconductor capacitors were fabricated with oxide thickness of 195nm, 420nm and 610nm respectively. The SiO₂ films were deposited on n-type Indium Phosphide(/nP) using Rapid Thermal Chemical Vapor Deposition (RTCVD). The characterization techniques employed in these experiments were (I-V) Current Voltage and High Frequency Capacitance Voltage (C-V) techniques. The electrical parameters obtained from the I-V and C-V measurements have been discussed here.

Electrical Characterization Of Preoxide Growth Fluorine Incorporated Thin Sio2 Films, Nilay J. Patel

Theses

Analyses of electrical characterization, of thin SiO₂ films grown on virgin and etched silicon surfaces, are presented here. The characterization techniques employed in these experiments are High Frequency Capacitance-Voltage (C-V), Capacitance-Time (C-T) & MOS Doping Profile and Static & Dynamic Current-Voltage (I-V) measurements. The structures, with areas ranging from 0.001-0.05 cm², used in this study are Al/Poly/SiO₂/Si/Al capacitors fabricated on virgin and C₂F₆ CHF₃ + He plasma exposed n-Si substrates. In this experiment, we have studied the effect of sacrificial oxidation. In this step, the oxide is thermally grown on the …

Mapping Hierarchical Structures Onto Hypercubes, Sandip C. Patel

Theses

Hierarchically structured arrays of processors are appropriate for low-level and intermediate-level image processing and computer vision. The most widely used structure is the pyramid. Neverthless, pyramid machines do not support the efficient implementation of the majority of scientific algorithms and their cost may become prohibitively high. In contrast, hypercube machines efficiently implement a wide variety of important algorithms due to the versatility of the underlying network. In fact, hypercube-based systems have become commercially available. The hypercube network supports both regular and irregular communications and it can efficiently simulate a variety of other structures like rings, trees, meshes, pyramids, etc. Thus, …

Efficient Multiprocessor Scheduling Based On Genetic Algorithms, Hong Ren

Theses

The problem of multiprocessor scheduling can be stated as finding a schedule for a general task graph to be executed on a multiprocessor system so that the schedule length can be minimized. This scheduling problem in known to be NP-hard and methods based on heuristic search have been proposed to obtain optimal and sub-optimal solutions to the problem. Genetic algorithms have recently received much attention as robust stochastic searching algorithms for various optimization problems. In this thesis, we propose an efficient method based on genetic algorithms to solve the multiprocessor scheduling problem. The representation of the search node will be …

A Microengineered Beam Diaphragm Structure For The High Performance Pressure Sensor, Alkesh Shah

Theses

The thesis details the design for a novel microengineered beam diaphragm structure for piezoresistive pressure sensor applications. The beam diaphragm structure is used as a pressure sensing device, within a Wheatstone bridge circuit. The single crystal silicon with [100] orientation is used for the beam diaphragm structure.

It has the advantages of high sensitivity(2.56 v/v/mm of Hg), good linearity(3Kpa to 1.4 Mpa) and overpressure protection with the help of the bosses. It's protection range is about 400 times the standard pressure range. The beam diaphragm structure has two rectangular bosses which are formed by anisotropic etching. Two pairs of diffused …

Magnetic Solvent Extraction, Jiann-Yang Hwang

Michigan Tech Patents

Particles of a magnetic material coated with a hydro- phobic surfactant are dispersed in an organic solvent extractant to produce a magnetic solvent extractant which can be used in solvent extraction processes. Phase separation of an organic phase, carrying the component to be separated, from the aqueous phase can be accelerated by applying a magnetic field to the organic phase. After removal of the organic phase, a magnetic field can be applied to the aqueous phase to remove any residual organic phase and thereby enhance the degree of separation.

Method Of Making High Strength Articles From Forged Powder Steel Alloys, Alfred A. Hendrickson, Darrell W. Smith

Michigan Tech Patents

High strength steel parts or articles are made from a powder alloy by compacting the powder into a preform, sintering the preform in a sintering furnace or the like under a highly-reducing atmosphere and at a temperature of at least 1150° C., cooling the preform, preheating the sintered preform in a highly-reducing atmosphere, such as an inert gas-based atmosphere containing hydrogen or pure hydrogen, to a temperature of at least 1000° C. and transferring the preheated preform to an impact forging device and impacting the preform at a peak averaging forging pressure of at least about 1000 MPa to obtain …

An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider

Dissertations and Theses

Since the need of energy conservation has become more and more urgent in the past decades, there has been an increased interest in the study and development of more efficient energy conversion systems. One of the fields that have arisen from that endeavor is a branch of physics called Finite Time Thermodynamics (FIT). It may be said that FIT was initiated through the famous paper by Curzon and Ahlborn (1975) that established new bounds on the efficiency of a finite time Carnot heat engine. Before, the traditional treatments gave a fundamental upper limit on the efficiency of any heat engine. …

Composition And Method For Radiation Synovectomy Of Arthritic Joints, D. E. Day, Gary J. Ehrhardt

Materials Science and Engineering Faculty Research & Creative Works

A method for preparing nonradioactive microspheres adapted for radiation synovectomy of arthritic joints in a mammal involves forming the microspheres by doping a biodegradable glass material which may be lithium or potassium silicate, lithium or potassium aluminosilicate, lithium or potassium aluminoborate, lithium or potassium germanate or lithium or potassium alumino- germanate with an isotope which may be samarium, holmium, erbium, dysprosium, rhemium or yttrium so that the isotope is chemcially dissolved in and distributed uniformly throughout the glass material. The doped glass material is then treated with an acid wash to produce a thin layer on the surface thereof and …

Integrated Neural Network And Machine Vision Approach For Intelligent State Identification, Cihan H. Dagli, Timothy Andrew Bauer

Engineering Management and Systems Engineering Faculty Research & Creative Works

An interfacing of neural networks (NNs) and machine vision to provide the next state of a system given an image of the present state of the system is presented. This interfacing is applied to a loading operation. First, a NN is trained for part recognition under conditions of rotation, location, object distortion, and background noise given an image of the part. Then, a second NN, given the output of the first NN and an image of a pallet being loaded, is trained for optimal part loading onto the pallet under conditions of noise in the image. The paradigm used is …

Acuta Enews August 1991, Vol. 20, No. 8

ACUTA Newsletters

In This Issue

President's column

Business meeting

Regional meetings

User groups

Director's column

Workshop in Atlanta

Electromagnetic Field Plot Of An Inductive Window By The Moment Method, John R. Natzke, Mark R. Wolski, Thomas Koryu Ishii

Faculty Publications - Department of Electrical Engineering and Computer Science

A moment method is used to plot the electromagnetic field of an inductive window in a TE10 -mode rectangular waveguide. Green's dyadic functions are derived based on Tai's approach, which is a modified form of Hansen's vector wave functions. Based on the computed electric fields, the S matrix and the equivalent aperture reactance of the waveguide window are calculated. This calculation agrees with the previously published closed-form results of Marcuvitz.

Efficient Single-Heterojunction Al0.27Ga0.73As/Gaas P-I-N Photodiodes With 22-Ghz Bandwidths, C. Johnson, S. Sloan, D. M. Braun, J. L. Russell, M. Zurakowski, M. Lightner, F. Kellert, G. Patterson, R. Koo, Dennis J. Derickson, J. E. Bowers

Electrical Engineering

A report is presented on the design, fabrication, testing, and modeling of single-heterojunction Al_0.27Ga_0.73As/Ga p-i-n photodiodes for use as components in optical receivers. The photodiodes are grown by molecular beam epitaxy and fabricated as 1100-μm² mesa structures. At 5-V reverse bias and 850 nm, 100 fF of capacitance, 90 pA of leakage current, 73% external quantum efficiency, <2% reflectivity, and 22-GHz bandwidths are typically measured.

Roughness Coefficients For Selected Residue Materials, John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Analysis of surface runoff on upland areas requires identification of roughness coefficients. A laboratory study is conducted to measure Darcy-Weisbach and Manning roughness coefficients for corn, cotton, peanut, pine needles, sorghum, soybeans, sunflower, and wheat residue. Varying rates of flow are introduced into a flume in which selected amounts of residue are securely attached. Roughness coefficients are calculated from measurements of discharge rate and flow velocity. The laboratory data are used to derive regression equations for relating roughness coefficients to Reynolds number and either percent residue cover or residue rate. Separate equations are developed for Reynolds number values from 500 …

Computer Aided Process Planning System For Generating Alternative Process Plans, Rao T. Gali

Masters Theses

Computer Aided Process Planning (CAPP) has a key role in Computer Integrated Manufacturing (CIM) as an interface between design and manufacturing. Current CAPP systems treat process planning as a static function, and always generate the same machine and process combinations. Thus, these CAPP systems are inadequate for advanced manufacturing facilities such as Flexible Manufacturing Systems (FMS). This thesis presents research conducted for the design and development of a CAPP system called Alternative Computer Aided Process Planning (A-CAPP) which generates alternative process plans by interacting with production planning and machine loading functions to satisfy system capacity constraints.

A-CAPP is a variant …

Comparing Simulated And Experimental Hysteretic Two-Phase Transient Fluid Flow Phenomena, R. J. Lenhard, J. C. Parker, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

A hysteretic model for two-phase permeability (k)-saturation (S)-pressure (P) relations is outlined that accounts for effects of nonwetting fluid entrapment. The model can be employed in unsaturated fluid flow computer codes to predict temporal and spatial fluid distributions. Consideration is given to hysteresis in S-P relations caused by contact angle, irregular pore geometry, and nonwetting fluid entrapment effects and to hysteresis in k-Srelations caused by nonwetting fluid entrapment effects. An air-water flow experiment is conducted with a 72-cm vertical soil column where the water table is fluctuated to generate scanning S-P paths. Water contents are measured via a gamma radiation …

The Effect Of Defense Management Review Decision 904, Stock Funding Depot Level Reparables, On Cash Flow Within The Reparable Support Division Of The Air Force Stock Fund, Deborah A. Elliot

Theses and Dissertations

This study investigated what the potential cash flow condition of the Reparable Support Division of the Air Force Stock Fund might be after final implementation of the procedures outlined in Defense Management Review Decision 904, Stock Funding Depot Level Reparables. The operation of the future Reparable Support Division was modelled using the General Purpose Simulation Software (GPSS/H) package and future cash flow conditions were projected through use of this model. Recommendations were then made based on the results of these projections and based on other data gathered during the course of the research process.

Evaluation Of Headwalls And Outlets For Geocomposite Edge Drains On I-75 And I-71, L. John Fleckenstein, David L. Allen, Jack A. Harison

Kentucky Transportation Center Research Report

Longitudinal, round, perforated pipe edge drains have been used along Kentucky roadways for approximately two decades. Panel (fin) edge drains were first used in Kentucky in 1984. Most of these edge drains were installed on the Interstate and Parkway systems.

Several problems related to the drains have been noted in the last seven years. A number of these problems have been observed to be related to flexible outlet pipes and headwalls.

A recent study was initiated to evaluate headwalls and outlets on I-75 from Lexington, Kentucky to Cincinnati, Ohio (approximately 70 miles) and on I-71 from Louisville, Kentucky to I-75 …

Ccfss News August 1991, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

Inhibited Spontaneous Emission By Photonic Band Gaps In A Square Lattice Of Periodic Dielectric Medium, Abdullah Al-Ghamdi

Masters Theses

The concepts of band theory for electrons can be employed to describe the behavior of electromagnetic waves propagating in two-dimensional, periodic dielectric structures. These two-dimensional, periodic structures can produce photonic band gaps in which the spontaneous emission by atoms embedded in the structure is prohibited and as a result the performance of many semiconductor devices can be enhanced. The calculations are based on finding the eigenvalues of the algebraic equation for the frequencies of electromagnetic waves moving in a square lattice composed of square dielectric rods with different dielectric constants.

Study Of Parameters Affecting Performance Of Automotive Transmission Filters, Debra Cauthen

All Theses

Modified isocyanate binders have been introduced as a possible alternative to phenolic resins for bonding nonwovens in automatic transmission filtration. The Occupational Safety and Health Administration (OSHA) and the American Conference of Governmental Industrial Hygienists (ACGIH) have placed restrictions on worker exposure to phenol-formaldehyde due to toxicological and ecological concerns. Modified isocyanates are unproven for bonding needlefelts in this application.

33rd Rocky Mountain Conference On Applied Spectroscopy

Rocky Mountain Conference on Magnetic Resonance

Program and registration information for the 33rd annual meeting of the Rocky Mountain Conference on Applied Spectroscopy, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 28 - August 1, 1991.

Associative Processing Implemented With Content-Addressable Memories, Luis Sergio Kida

Dissertations and Theses

The associative processing model provides an alternative solution to the von Neumann bottleneck. The memory of an associative computer takes some of the responsibility for processing. Only intermediate results are exchanged between memory and processor. This greatly reduces the amount of communication between them. Content-addressable memories are one implementation of memory for this computational model. Associative computers implemented with CAMs have reported performance improvements of three orders of magnitude, which is equivalent to the performance of the same application running in a conventional computer with clock frequencies of the order of GHz. Among the benefits of content-addressable memories to the …