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Articles 176611 - 176640 of 197992

Full-Text Articles in Engineering

An Integrated Mrp And Finite Scheduling System To Derive Detailed Daily Schedules For A Manufacturing Shop, Sita D. Nathan Jan 1994

An Integrated Mrp And Finite Scheduling System To Derive Detailed Daily Schedules For A Manufacturing Shop, Sita D. Nathan

Theses

Many companies rely on Material Requirements Planning (MRP) to support their Production Scheduling and Control (PS&C) functions. Since MRP does not provide a detailed shop floor schedule, these users have to implement either a third party procedure or an internally developed procedure for shop floor controls. In this thesis we consider a class of user shops which are characterized by the following features:

  • Homogenous machines, that is all machines can produce all products.

  • Each product requires a setup, but several products may have a common setup.

  • MRP requirements are specified on a weekly basis while actual requirements are specified on …


Time Frequency Analysis Of The Electromyogram During Fatigue, Michelle Rene Davies Jan 1994

Time Frequency Analysis Of The Electromyogram During Fatigue, Michelle Rene Davies

Theses

Spectral parameters obtained from the surface EMG signal have been used as indicators of fatigue during a sustained contraction. These same parameters have not been tested with the EMG signals obtained from fine wire electrodes. One such parameter is the median frequency which is known to decline with fatigue. A comparison was done between the median frequencies obtained from the surface EMG and those obtained from the fine wire EMG. The median frequencies from both types of electrodes decreased with time indicating that fine wire electrodes could be used to measure fatigue.

In addition, a new technique, time frequency analysis, …


Application Of The Wavelet Transform To Biomedical Signals, Karl O. Hauck Jan 1994

Application Of The Wavelet Transform To Biomedical Signals, Karl O. Hauck

Theses

The basic concepts and fundamentals of the wavelet signal representation were examined. The orthonormal wavelet was selected for this project after being compared to various types of wavelets. The orthonormal wavelet was chosen due to the equal time and frequency resolution exhibited in the wavelet coefficients. Programs were written in Matlab to implement the orthonormal wavelet in developing wavelet coefficients for a given signal. The programs include the conditions for an orthonormal wavelet in and which produce the wavelet filters g(n) and h(n). The wavelet filters were then incorporated into another program that applied Mallat's multiresolution algorithm for a given …


Transient Behavior Of An Adaptive Synchronous Cdma Receiver, Bin Zhu Jan 1994

Transient Behavior Of An Adaptive Synchronous Cdma Receiver, Bin Zhu

Theses

A steepest descent algorithm is used to update the adaptive weights of a two-stage synchronous Code-Division Multiple-Access (CDMA) receiver that was proposed recently. An issue of the adaptive CDMA system - the convergence and stability property of the receiver is investigated in this thesis.

This adaptive synchronous CDMA receiver uses a decorrelator at the first stage and adopts a neural network which acts as an interference canceler at the second stage. It can achieve near-optimum performance. Furthermore, its computational complexity is just a square function of the number of users. The only requirement is the knowledge of the users' signature …


Geotechnical Characterization Of Water Treatment Plant Residuals, Zhengyuan Xia Jan 1994

Geotechnical Characterization Of Water Treatment Plant Residuals, Zhengyuan Xia

Theses

Evaluation of engineering properties of water treatment plant (WTP) residuals is a critical part in predicting their behaviors in monofills. In this study, ten WTP residual samples were collected from ten water treatment plants across the United States. Their general chemical/physical and geotechnical properties including liquid and plastic limits, compaction) shear strength, permeability and durability characteristics were determined.

It was observed that the geotechnical properties of WTP residuals are influenced by various factors such as mineral particle composition, organic content, type and amount of chemical additives) and time of aging, etc. Based on this study, the behavior of WTP residual …


An Adaptive Fusion Model For Distributed Detection Systems With Unequiprobable Sources, Yuzheng Zhang Jan 1994

An Adaptive Fusion Model For Distributed Detection Systems With Unequiprobable Sources, Yuzheng Zhang

Theses

In a traditional communication system, a single sensor such as a radar or a sonar is used to detect targets. Since the reliability of a single sensor is limited, distributed detection systems in which several sensors are employed simultaneously have received increasing attention in recent years. We consider a distributed detection system which consists of a number of independent local detectors and a fusion center. Chair and Varshney have derived an optimal decision rule for fusing decisions based on. the Baysian criterion. To implement such a rule, the probability of detection PD and the probability of false alarm …


Fast Point Pattern Matching By Heuristic And Stochastic Optimization Techniques, Ashish Agrawal Jan 1994

Fast Point Pattern Matching By Heuristic And Stochastic Optimization Techniques, Ashish Agrawal

Theses

This work is concerned with one of the methodologies used in the final stages of machine vision: the matching of model point patterns to observed point patterns. Conventional search methods not only fail to arrive at the optimal match, but are also computationally expensive and time consuming. To arrive at the optimal pattern match, stochastic and heuristic optimization as the search technique, exploiting Simulated Annealing (SA), Evolutionary Programming (EP) and Mean Field Annealing (MFA), are explored in detail. A comparison of results obtained using SA versus "hill-climbing" and "exhaustive search" techniques, and results of EP are presented. The relative effectiveness …


Fabrication Of Micron-Sized Mirror/Cantilever Silicon Devices For Crosspoint Switching Arrays, Yasser A. Abdel-Aziez Jan 1994

Fabrication Of Micron-Sized Mirror/Cantilever Silicon Devices For Crosspoint Switching Arrays, Yasser A. Abdel-Aziez

Theses

This thesis describes the fabrication of micron-sized vertical mirrors at the end of horizontal cantilevers, that are electrostatically controlled. The mirrors, 40x 40 μm with thicknesses of 1.5-6 μm, were made by using the etch resistance to 40% KOH etchant of <111> planes and oxide stripes. The cantilever beams, 100 to 350 μm long and 0.44 to 0.81 μm thick, were fabricated using the etch resistance of heavily doped boron layers to 10% KOH at 50 °C. Two technologies to introduce the boron layers were investigated. The ion implantation approach was based on thick oxide/photoresist masking. A maximum doping of 2.5 …


Fluid Flow Modeling For Pneumatically Fractured Formations, Deepak Nautiyal Jan 1994

Fluid Flow Modeling For Pneumatically Fractured Formations, Deepak Nautiyal

Theses

This thesis investigates the flow of compressible fluids in pneumatically fractured formations. Pneumatic fracturing is a recently developed technique for increasing permeability in geologic formations by the controlled injection of high pressure air. The artificially induced fractures enhance the flow rate of liquids and vapors in the subsurface, and can be applied to in situ remediation of hazardous waste sites, and for other hydrogeological applications.

A flow model for discrete fractures is derived based on the assumptions of viscous, laminar fluid flow through planar fractures (Poiseuille type flow). The model takes into account non-linearity introduced by gas compressibility effects. Provision …


An On-Line Approach For Evaluating Trigonometric Functions, Rajesh Amin Jan 1994

An On-Line Approach For Evaluating Trigonometric Functions, Rajesh Amin

Theses

This thesis investigates the evaluation of trigonometric functions based on an on-line arithmetic approach. On-line algorithms have been developed to evaluate the sine and cosine functions. Error analysis and heuristics are carried out to arrive at a minimal error algorithm based on the series expansion of the sine and cosine function.

A logical design based on the algorithm is presented where the unit is designed as a set of basic modules. A detailed bit slice design of each module is also presented. A simulator was designed as an experimental tool for synthesis of the on-line algorithms, and a tool for …


Biomechanical Comparison Of Interosseous And Subperiosteal Flexor Tendon Reattachment, Alisa Beth Olin Jan 1994

Biomechanical Comparison Of Interosseous And Subperiosteal Flexor Tendon Reattachment, Alisa Beth Olin

Theses

This study was undertaken to biomechanically compare the interosseous and subperiosteal distal flexor tendon reattachment techniques. Twenty New Zealand white rabbits underwent division of the right second and third hind limb profundus flexor tendon distal to the insertion of the superficial flexor. All tendons were repaired using the Kleinnert-Bunnell configuration with a 5-0 nylon tied over a cotton pad on the dorsum of the digit. In half of the animals, the second profundus was reattached into a hole in the middle phalanx and the third profundus was reattached after periosteal stripping of the middle phalanx. The other animals underwent subperiosteal …


Development And Evaluation Of A Nfweav Simulation Model For Weaving Areas Under Non-Freeway Condition, Wen-Min Pan Jan 1994

Development And Evaluation Of A Nfweav Simulation Model For Weaving Areas Under Non-Freeway Condition, Wen-Min Pan

Theses

The development of a microscopic digital computer simulation model representing vehicle interaction at a weaving area under non-freeway condition is presented. Weaving areas are classified into two categories: 1. Weaving caused by merging and diverging of a ramp with an arterial, 2. On/off ramps connecting an arterial with a highway. The principal characteristics of the simulation model are the following: 1) a car following and lane changing model were used to represent vehicle movements; 2) an anti-collision check algorithm was developed for all vehicle movements; 3) driver merging urgency and follower courtesy model were developed for weaving vehicles. The simulation …


Performance Of National Research And Education Network While Transmitting Healthcare Information Data, Bhavesh Mahendra Shukla Jan 1994

Performance Of National Research And Education Network While Transmitting Healthcare Information Data, Bhavesh Mahendra Shukla

Theses

National Research and Education Network(NREN) is a first step in the process of building a National Information Infrastructure(NII). NII will ultimately lead to Broadband Integrated Services Digital Network(B-ISDN), a network which will support global exchange of voice, data, images and video.

NREN will evolve out of present National Science Foundation Network (NSFNET), also known as Interim NREN. At present NSFNET operates at 45 MBits/sec. By 1996, there are plans to boost the data rate to 155 MBits/sec and to 620 MBits/sec by the turn of century.

In this thesis, present actual NSFNET is simulated using software simulation tool Networkll.5. The …


Performance Modeling Of High Data Rate Ring Networks Using Stochastic Petri Nets, Le Zhong Jan 1994

Performance Modeling Of High Data Rate Ring Networks Using Stochastic Petri Nets, Le Zhong

Theses

This thesis has proposed a performance analysis method for Carrier Sensing Multiple Access Ring Network (CSMA) based on Petri net methodologies. The method can offer more accurate results than traditional queuing methods, but less than simulation results. In the CSMA network access protocol is studied in this thesis, when a passing message is detected by a station, it stops transmitting immediately in order to avoid a collision.

A generalized stochastic Petri nets model is made first, then the SPNP package is used to do the analysis. The analysis results show that even at a very heavy load fraction of near …


Laser Treatment Of Ceramic Coatings On Defective Ceramic Glazed Tile, Gousinn Yu Jan 1994

Laser Treatment Of Ceramic Coatings On Defective Ceramic Glazed Tile, Gousinn Yu

Theses

Laser surface melting treatment was achieved by a 2 Kw CO2 surgical laser system.The partially defocused laser beam provided a circular spot with an annular energy distribution on the sample.

It is certain that laser surface treatment will do the job of repairing in defective ceramic tiles. All glazes provided by American Standard were tested for an ability of withstand laser treatment when coated on to a glazed tile. In order to repair the defective ceramic tile it is necessary to patch the damaged region with a cement. The cement must then be glazed in order to match that of …


Design Of An Autonomous Vehicle System, Fritz Gerald Momplaisir Jan 1994

Design Of An Autonomous Vehicle System, Fritz Gerald Momplaisir

Theses

With advances in electronics, mobile vehicles are becoming more and more sophisticated. The Potential applications of AGVs are numerous an range from a material handling system for the factory floor to an intelligent wheel chair for the handicapped. The design of these vehicles, however, remains a difficult task. Even when the machine is given precise information about its environment, the fact that it is never free of noise further complicate the situation. One of the goals of an AGV project is to design a robust system that will operate efficiently in the presence of different sources of noise.

The scientific …


A Hybrid Low Bit-Rate Video Codec Using Subbands And Statistical Modeling, Ferhat Cakrak Jan 1994

A Hybrid Low Bit-Rate Video Codec Using Subbands And Statistical Modeling, Ferhat Cakrak

Theses

A hybrid low bit-rate video codes using subbands and statistical modeling is proposed in this thesis. The redundancy within adjacent video frames is exploited by motion estimation and compensation. The Motion Compensated Frame Difference (MCFD) signals are decomposed into 7 subbands using 2-D dyadic tree structure and separable filters. Some of the subband signals are statistically modeled by using the 2-D AR(1) technique. The model parameters provide a representation of these subbands at the receiver side with a. certain level of error. The remaining subbands are compressed employing a classical waveform coding technique, namely vector quantization (VQ).

It is shown …


Modeling Arsenic Transformation In Clay Soils, Chao-Yi Chung Jan 1994

Modeling Arsenic Transformation In Clay Soils, Chao-Yi Chung

Theses

This project is designed to estimate the possible transformation forms of arsenic in clay soil. A computer model was established to simulate arsenic transformations. The amount of arsenic species adsorbed, dissolved, and the predominant soluble species are calculated by the model, which is mainly based on the Freundlich adsorption isotherm, solubility data collected by Keaton and Kardos, and pH-Eh diagram established by Ferguson and Garvis. The computer language used is Turbo PASCAL version 5.5.

The clay soil environment is considered to be in standard state: 25°C 1 atm. Environmental factors of the soil system which are accounted for by the …


Adaptive Notch Filter, Yuchen Huang Jan 1994

Adaptive Notch Filter, Yuchen Huang

Dissertations and Theses

The thesis presents a new adaptive notch filter (ANF) algorithm that is more accurate and efficient and has a faster convergent rate than previous ANF algorithms. In 1985, Nehorai designed an infinite impulse response (UR) ANF algorithm that has many advantages over previous ANF algorithms. It requires a minimal number of parameters with constrained poles and zeros. It has higher stability and sharper notches than any ANF algorithm until now. Because of the special filter structure and the recursive prediction error (RPE) method, however, the algorithm is very sensitive to the initial estimate of the filter coefficient and its covariance. …


Minutes Of The Friends Of The Tractor Test And Power Museum January 5th 1994, Tractor Museum Jan 1994

Minutes Of The Friends Of The Tractor Test And Power Museum January 5th 1994, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

No abstract provided.


Applications Of Object Database Technology In Thermodynamics And Materials Science, R Venkatesh, David Hansen, David Maier, James T. Stanley Ii Jan 1994

Applications Of Object Database Technology In Thermodynamics And Materials Science, R Venkatesh, David Hansen, David Maier, James T. Stanley Ii

Faculty Publications - Department of Electrical Engineering and Computer Science

Over the last few decades there has been a continual development of computer programs and databases directed at storage and manipulation of scientific data. The data these programs manipulate are typically kept in a proprietary format with little thought given to portability, upgrading or interfacing with other software. Hence, there is an inability to share data across programs of between data sources. We believe that many of the difficulties with sharing scientific data and building on previous computational efforts result from the incompatibility of programs and data in the scientific domain. We are involved in exploring an alternative data management …


Gravity And Electromagnetism In Noncommutative Geometry, Giovanni Landi, Nguyen Ai Viet, Kameshwar C. Wali Jan 1994

Gravity And Electromagnetism In Noncommutative Geometry, Giovanni Landi, Nguyen Ai Viet, Kameshwar C. Wali

Physics - All Scholarship

We present a unified description of gravity and electromagnetism in the framework of a Z 2 non-commutative differential calculus. It can be considered as a “discrete version” of Kaluza-Klein theory, where the fifth continuous dimension is replaced by two discrete points. We derive an action which coincides with the dimensionally reduced one of the ordinary Kaluza-Klein theory.


Coping With The Risk Of Cancer In Children Living Near Power Lines, Eileen N. Abt Jan 1994

Coping With The Risk Of Cancer In Children Living Near Power Lines, Eileen N. Abt

RISK: Health, Safety & Environment (1990-2002)

Ms. Abt briefly summarizes evidence linking power lines with a possible increase in risk of childhood cancer. She also recounts how, although many experts remain skeptical of causality, public fears, whether or not warranted, have themselves created serious problems. Finally, she proposes ways to address those problems.


Acuta Enews January 1994, Vol. 23, No. 1 Jan 1994

Acuta Enews January 1994, Vol. 23, No. 1

ACUTA Newsletters

In This Issue

Board Report

Presidents message

FCC proposes regulations for toll fraud

Cruising he information superhighway

21st century technology


Acuta Enews January 1993, Vol. 23, No. 1 Jan 1994

Acuta Enews January 1993, Vol. 23, No. 1

ACUTA Newsletters

In This Issue

Regulatory update

President's column

Grants to network innovators

Monograph honoraria $500

Phone fiber to carry CATV

Director's column


Fuzzy Knowledge-Based Approach To Treating Uncertainty In Inventory Control, Dobrilla Petrovic, Edward Sweeney Jan 1994

Fuzzy Knowledge-Based Approach To Treating Uncertainty In Inventory Control, Dobrilla Petrovic, Edward Sweeney

Articles

Inventory control in complex manufacturing environments encounters various sources of uncertainity and imprecision. This paper presents one fuzzy knowledge-based approach to solving the problem of order quantity determination, in the presence of uncertain demand, lead time and actual inventory level. Uncertain data are represented by fuzzy numbers, and vaguely defined relations between them are modeled by fuzzy if-then rules. The proposed representation and inference mechanism are verified using a large numbers of examples. The results of three representative cases are summarized. Finally a comparison between the developed fuzzy knowledge-based and traditional, probabilistic approaches is discussed.


A Probabilistic Model For Avcs Longitudinal Collision/Safety Analysis, Jacob Tsao, Randolph Hall Jan 1994

A Probabilistic Model For Avcs Longitudinal Collision/Safety Analysis, Jacob Tsao, Randolph Hall

Faculty Publications

This paper develops a probabilistic model for analyzing longitudinal collision/safety between an abruptly decelerating vehicle and its immediate follower. The input parameters are the length of the gap between the two vehicles, their common speed prior to the failure, the reaction delay of the following vehicle and a bivariate distribution for the two deceleration rates. The output includes the probability of a collision and the probability distribution of the relative speed at collision time We use this model to compare the safety consequences associated with the platooning and “free-agent” longitudinal-separation rules. We also demonstrate that the free-agent rule implemented with …


Intergranular Corrosion-Fatigue Failure Of Cobalt-Alloy Femoral Stems. A Failure Analysis Of Two Implants, Jeremy L. Gilbert, Christine A. Buckley, Joshua J. Jacobs, Kim C. Bertin, Michael R. Zernich Jan 1994

Intergranular Corrosion-Fatigue Failure Of Cobalt-Alloy Femoral Stems. A Failure Analysis Of Two Implants, Jeremy L. Gilbert, Christine A. Buckley, Joshua J. Jacobs, Kim C. Bertin, Michael R. Zernich

Biomedical and Chemical Engineering - All Scholarship

Two modular hip implants with a cobalt-alloy head and a cobalt-alloy stem were retrieved after a fracture had occurred in the neck region of the femoral component, eighty-five and seventy months after implantation. Both implants failed less than one millimeter distal to the taper junction between the head and the stem (outside of the taper). The fracture surfaces of the implant were investigated with the use of scanning electron microscopy, to determine the nature of the failure process. The fractures occurred at the grain boundaries of the microstructure and appeared to be the result of three factors: porosity at the …


A Method For Computing Stokes Flow Interactions Among Spherical Objects And Its Application To Suspensions Of Drops And Porous Particles, Ashok S. Sangani, Guobiao Mo Jan 1994

A Method For Computing Stokes Flow Interactions Among Spherical Objects And Its Application To Suspensions Of Drops And Porous Particles, Ashok S. Sangani, Guobiao Mo

Biomedical and Chemical Engineering - All Scholarship

A method for computing Stokes flow interactions in suspensions of spherical objects is described in detail and applied to the suspensions of porous particles, drops, and bubbles to determine their hydrodynamic transport coefficients.


Winter 1994, 90.9 Wmpg Fm Jan 1994

Winter 1994, 90.9 Wmpg Fm

WMPG Program Guides

No abstract provided.