Engineering Commons^™

Performance Evaluation And Sequence Control Of An Automatedmanufacturing System, Vijaykumar D. Desai

Theses

In an automated sequential manufacturing system Programmable Logic Controllers (PLC) are widely used. As the control specification varies, the control software needs to be rewritten to accommodate the new specification. Since PLC has high flexibility, one can update the current system while it is running thereby making easier implementation. In order to design flexible, reusable and maintainable control software, a good modeling tool is required. Petri nets are such a tool. Which facilitates analysis of behavioral properties, performance evaluation, and systematic construction of discrete event simulators and controllers. In this thesis a system with one robot and five sequential work …

Viscoelastic Effects On Parallel Flow Stability, Transition To Turbulence, And Turbulent Flow, Michael Garofalo

Theses

The classical two dimensional theory of stability of parallel flow is extended to viscoelastic fluids. How the elasticity of the fluid affects the point of stability and determines the point of transition to turbulence is analyzed. In addition the magnification of disturbances is elucidated. This study is based on a viscoelastic constitutive equation which has been successful in predicting the experimental trends of various unsteady high shear rate laminar flows. A viscoelastic stability equation which is an extension to the Orr-Sommerfeld equation for a Newtonian fluid is derived and solved for a flow between parallel plates superimposed by a two-dimensional …

The Mobile Satellite Service (Mss) Systems For Global Personal Communications, Kiho Lee

Theses

A worldwide interest has arisen on personal communications via satellite systems. The recently proposed mobile satellite service(MSS) systems are categorized four areas: geostationary earth orbit(GEO) systems, medium earth orbit(MEO) systems, low earth orbit(LEO) systems, and highly elliptical orbit(HEO) systems. Most of the systems in each category are introduced and explained including some technical details. The communication links and orbital constellations of some systems are analyzed and compared with different categories, and with different systems. Some economical aspects of the systems are mentioned. The regulatory issues about frequency spectrum allocation, and the current technical trends in these systems are summarized.

Mechanical Behavior Of Polystyrene Foam Bead Lightweight Concrete, Hai-Ying Ni

Theses

This thesis is designed to investigate the effect of porosity on the mechanical properties (strength and modulus) of concrete, and to evaluate the effect of silica fume on the mechanical properties of the polystyrene foam bead lightweight concrete. In this research we made the lightweight concrete by using polystyrene foam beads as light weight aggregate and studied its mechanical properties in detail. Due to the near zero density and modulus of foam beads, we were able to consider it as "porosity". We could then control porosity in concrete by varying foam bead volume fraction.

In our experiments we used the …

Volatilization Of Volatile Organic Compounds From Complex Wastewaters, Syed Sikandar Qadry

Theses

A variety of volatile organic solvents used in the pharmaceutical and specialty chemical industries end up in wastewater collection and treatment systems. EPA has classified these VOCs into groups depending on their potential to volatilize from the wastewaters. In making this classification, Henry's Law, which is valid at very low concentrations, has been used to describe the vapor-liquid equilibrium. But, in reality the concentrations observed in the wastewaters are often too high for Henry's Law to be valid and it is inappropriate to assume that equilibrium has been achieved for every compound.

This project evaluates the volatilization rates, both experimental …

Area And Perimeter Measurements Of Cells With Bound Fluorescent Antibodies, Aicha Weiss

Theses

The objective of this research was to geometrically analyze the characteristics of cells, specifically area and perimeter. The images were transferred from HP A900 system to an AVS work station. The images were visualized and manipulated by the AVS which permits the distinction between the cell body, fluorescent object, and background. The intrinsic geometry of the cell was determined by using image processing algorithms written in C. The images were then passed through a threshold filter, thereby yielding a black background and a white cell body. The perimeter calculation was then applied to the black and white images. Two test …

Case Study Of Assembly Defects In Manufactured Products, Michael J. Withka

Theses

Design for Quality Manufacturability (DFQM) is a design tool that empowers engineers to create designs that are easily and effectively transformed into manufactured products. The goal of this methodology is to make designers aware of design characteristics that may lead to product defects during the assembly process. Acknowledging the possibility of these defects will enable the designer to institute design modifications early in the design phase. The benefits realized in this approach are a reduction in the number of defects in the finished product, reduced product cycle times, a reduction in monitoring costs and a reduction in time-to-market.

This thesis …

Preoperative Risk Assessment For Cardiac Surgery Using Piecewise Linear Regression Model, Arifa Zafar

Theses

In the present climate of quality assurance policies, rigorous requirements for informed consent, and a constantly changing patient population, a system of preoperative risk assignment for cardiovascular surgery was developed to monitor and evaluate surgical outcomes. The goal of this work is to estimate the preoperative risk associated with cardiac bypass surgery for patients in different risk categories. These risk categories are determined by the Parsonnet model which is based upon studying the severity of illness. The Parsonnet model assigns a risk value to a range of risk factors consisting of patient attributes and disease parameters. The aggregate of these …

Time Domain And Frequency Domain Analysis Of Myoelectric Signals During Muscle Fatigue, Rakesh M. Maniar

Theses

Spectral analysis of the EMG signal is a useful tool for studying the complex phenomena of fatigue. The spectral parameters of mean frequency and median frequency, and the time domain parameter of root mean square have been used to measure localized fatigue.

The normal values of median frequency and its decline with fatigue have not as yet been determined in healthy subjects. This should be done in order to apply spectral analysis for clinical evaluations of abnormal populations. Normal median frequency values and its slope were established in this work for the upper extremity muscles of biceps, triceps and deltoid …

Use Of Multiple Transmitters For 3-D Non-Intrusive Particle Tracking, Jitesh H. Agrawal

Theses

A method for non-intrusive tracking of a particle in 3-dimensional space, based on processing of signals emitted from a transmitter embedded in the particle, is being developed. This method uses a mathematical model, which predicts the induced signal in receivers present in the vicinity of flowing particle, and supporting numerical techniques. Specific application aspects related to improving the accuracy of this method are presented.

The focus here is the development of flexible software capable of processing information coming from multiple transmitters with known distinct spatial orientation. Implementation aspects of modified existing empirical corrections for improving model-reality agreement, and new techniques …

A Systematic Approach To Defense Diversification, Sathappan Venkatachalam

Theses

The decline in defense spending has resulted in defense dependent companies seeking new markets through re-designing existing products, developing new products and restructuring their businesses. Defense diversification is defined as the process of transitioning a defense company's core capabilities (technologies, products, services) into commercial and non-Department of Defense government markets. A combination of site visits and review of the literature on defense diversification demonstrates the need for diversifying companies to adopt a systematic approach.

A concurrent new product development/product redevelopment model is proposed, based on the principles of concurrent engineering. The model consists of an eight phase development cycle and …

Design For Quality Manufacturability Analysis Of Missing/Misplaced Parts And Part Interference, Altaf Yusuf Tamboo

Theses

Design for Quality Manufacturability (DFQM) is an approach that addresses the issue of quality manufacturability (QM) - the likelihood that defects will occur during manufacture of a product in a standard plant. The DFQM methodology is based on the premise that defects found in assembled products are often influenced by some features of the design and/or assembly process (influencing factors). These influencing factors cause defects in the presence of certain error catalysts.

One of the influencing factors is geometrical features such as shape and symmetry. A classification scheme for part shape and symmetry is developed. This scheme is summarized in …

Scheduling Of Flexible Manufacturing Systems With Automated Guided Vehicles Using Petri Net Models, Hua-Sheng Chiu

Theses

In this thesis, Petri net models for Flexible Manufacturing Systems (EMS) are constructed. A firing sequence of the Petri net from the initial marking to the final marking can be seen as a schedule of the modeled FMS. By using the branch-and-bound algorithm, an optimal schedule of the FMS can be obtained.

Automated Guided Vehicle Systems (AGVS) are increasingly used for material handling in factories and warehouses. An AGVS can reduce labor costs and is ready to be integrated into an automated factory. This thesis presents two AGVS models (shared and duty) which integrate the control of AGVS with the …

Wear And Friction Of Hylamer And Polyethylene Against Cobalt Chromium A Pin-On-Disc Study, Jerry D'Alessio, Ii

Theses

Understanding friction and wear of biomaterials is essential to the success of any prosthetic joint. A pin-on-disc wear tester is used to find the friction and wear of pins of one material on a coupon of medical grade cobalt chrome. In this experiment six pins of UHMWPe (ultra high molecular weight polyethylene) and six pins of Hylamer® from Du Pont Manufacturing were tested. Four separate runs were made. The tests were performed for ten million cycles, stopping every one to one and a half million cycles for data acquisition. Volumetric wear, wear rate, and coefficients of friction were measured. Both …

An Adaptive Asynchronous Cdma Receiver And Its Convergence Analysis, Lizhi Zhong

Theses

An adaptive CDMA receiver scheme assuming perfect synchronization has been generalized in this thesis to the asynchronous channel, a much more practical assumption of the real system. Similar formulas are derived and as its synchronous version, it is still near-far resistant and requires no knowldge [sic] of received signal amplitudes and training sequences. Thus, sophisticated high-precision power control and user power estimation are not necessary and the receiver is particularly useful in mobile communications since it can adjust itself adaptively to changes in the power of the users. Tile convergence and transient behavior of the receiver are also investigated and …

Heart Rate Variability Studies On Ambulatory Subjects Using Ekg Derived Respiration, Xiaorui Tang

Theses

Power spectral analysis of heart rate variability (HRV) provides a powerful non-invasive too] for exploring the balance between sympathetic and parasympathetic components of the autonomic nervous system. In the spectrum of HRV, there are three distinct peaks. The high frequency (HF) band (0.15 to 0.4 Hz) is correlated with parasympathetic activity and this is the band of interest 'in the study.

Two OTOUPS Of SL113jeCtS were considered in this work, stroke survivors and subjects performing an oral presentation in front of an audience. Data were collected with a Holter monitor to allow for ambulatory recording. Respiration was derived from the …

Soft Decision Adaptive Multiuser Cdma Detector For Asynchronous Awgn Channels, Frank Viehofer

Theses

A multiuser detector in an asynchronous, additive white Gaussian noise, codedivision multipleaccess (CDMA) channel is proposed and analyzed. It employs a combination of a decorrelator and a nonlinear multiuser interference canceler that utilizes soft tentative decisions. The weights of the canceler are adaptively adjusted, in a manner that renders the knowledge of received signal energies and the use of training sequences unnecessary. The steady state error performance of the detector is obtained and found to be superior to the performance of the same detector that utilizes hard tentative decisions.

Stress-Strain Behavior Of High Strength Concrete Cylinders, Danqing Chen

Theses

Due to the recent development of high strength concrete in engineering and construction, it has become more important to study the behavior of materials in structures.

No results have been previously published in the literature regarding the influence of aspect ratio in plain high strength concrete cylinders on stress-strain behavior under uniaxial compression.Thus at present study, compression tests were conducted on 3x6 in., 3x9 in., and 3x12 in. plain high strength concrete cylinders to study their stress-strain behavior. Plain normal strength concrete cylinders were also tested and used for comparative study.

Based on the present investigations, attempting to obtain a …

Single-Axis Agonistic Motion Control System With Electro-Magnetic Actuators, Alexander Rokhvarg

Theses

A novel single-axis motion control system using solenoid electromagnet actuators is built and successfully controlled using a non-linear real-time control algorithm. Procedures for defining and modeling the electromagnetic actuator are established and implemented. Discrete-time nonlinear control law with global asymptotic stability and zero steady-state error is designed and numerically optimized. Stable operation with small-signal 0dB crossover frequency of 370 Rad/sec and positioning RMS steady-state error of better than 4 micron is achieved. Time domain parameters are verified on a working prototype. A step reference response positioning a 0.35 Kg mass payload over 1 cm travel in under 30 milliseconds is …

Investigation Of Velocity Distribution Within High Speed Waterjet, Hong Cao

Theses

The aim of this research was to investigate velocity distribution within the water jet at different conditions of jet formation. The water jet (WJ) velocity was measured by the use of Laser Transit Anemometer (LTA) and statistical technique which improved the accuracy of the velocity determination.

The velocities were measured for different diameters of the sapphire nozzle under different water pressures at different axial stand off distances and radial distances across the jet. The experiments performed in this study enabled us to evaluate the effects and conditions of the water jet on the velocity distribution. The acquired results provide information …

Development Of An Expert System To Facilitate A Pump Manufacturing/Warehouse Facility, Muhammad Mutahir Ghauri

Theses

The objective of this study is to evaluate the effectiveness of utilizing an expert system technology as it relates to manufacturing. It appears that our industries are still uncertain about this technology. In the first phase of this study, procedure for deployment of this technology is discussed. Secondly a knowledge-based expert system is developed, using a VP-Expert microcomputer shell. The system is made of three modules, inventory module, cost analysis module, and decision making module (for the selection of pumps).

A warehouse was selected for the analysis, which carries the finished product in the form of pumps. The quantities and …

Measurement Of The Reaction To Stress And Meditation Using Brain Wave Coherence And Heart Rate Variability, Christopher B. King

Theses

Measurement of physiological parameters associated with the stress response and the relaxation response caused by various forms of meditation can provide valuable information about the reaction of the body to the mind and to the external environment.

This study used two different techniques to evaluate physiological parameters. The first part examined the meditation response by recording the EEG and calculating the coherence between brain waves originating from different parts of the brain. It was found that high levels of coherence in the alpha portion of the EEG frequency band coincided with a restful state associated with the relaxation response. In …

A Pharmacokinetic Model Of The Liver, Samirbhai Rameshbhai Patel

Theses

The liver is the major organ where chemical breakdown of organic and inorganic compounds takes place. A pharmacokinetic heterogeneous model was developed for the local anesthetic and antiarrhythmic drug lidocaine. It was assumed that transport and elimination of lidocaine and its metabolites are linear with concentration. Simulations were done using VisSim software on a 486 based personal computer to obtain concentration profiles for hepatic clearance and for step input of the drug and its metabolites. It was found that the rate of uptake and rate of breakdown were 0.48 min^-1 and 0.49 min^-1 respectively for lidocaine. The results …

Analysis Of Intermodulation Distortion For Mesfet Small-Signal Amplifiers, Imad Saleh Ahmad

Dissertations and Theses

Using the nonlinear Volterra series representation, analytical expressions for the third-order intermodulation distortion power and intercept point for a MESFET small-signal amplifier are derived when its equivalent circuit is bilateral and includes the gate-to-drain capacitance (C_gd) explicitly as a nonlinear element. Previously developed analytical expressions treated C_gd as a linear element or incorporated it as part of gate-to-source and drainto- source capacitances (C_gs and C_ds). These new analytical expressions are then compared with experimental data and good agreement is obtained. The analytical expressions are also used to study the variation of intermodulation distortion with …

Assessment Of Non-Mechanical Thermo-Syphon Solar Pump, Tarek Hassan Selim

Archived Theses and Dissertations

No abstract provided.

Efficient Axis And Circle Detection Through Hough Transformation, Karissa E. Hobert

Presidential Scholars Theses (1990 – 2006)

Computer vision and human vision are quite different. While a person can look at an object and easily recognize it, a computer is does not understand the the objects it is seeing. Finding axes and circles in an image is an intermediate step in designing a machine with the ability to recognize shapes and objects. Through the utilization of contour and smoothed local symmetry information, the main axes of an image are determined and may be used to facilitate shape and object analysis. A Hough transform algorithm detects the most popular lines from a set of candidate axis points. This …

Nonlinear Robust Control Of A Series Dc Motor Utilizing The Recursive Design Approach, Michael J. Burridge

Retrospective Theses and Dissertations

In this thesis, the investigation of asymptotic stability of the series DC motor with unknown load-torque and unknown armature inductance is considered. The control technique of recursive, or backstepping, design is employed. Three cases are considered. In the first case, the system is assumed to be perfectly known. In the second case, the load torque is assumed to be unknown and a proportional-integral controller is developed to compensate for this unknown quantity. In the final case, it is assumed that two system parameters, load torque and armature inductance, are not known exactly, but vary from expected nominal values within a …

Impact Of Artificial Reef Associates On Macrobenthic Community Structure In Florida Bay, Heinz Michael Proft

Dissertations, Theses, and Masters Projects

No abstract provided.

Crassostrea Virginica On Constructed Intertidal Oyster Reefs: The Effects Of Tidal Height And Substrate Level On Settlement, Growth, And Mortality, Ian K. Bartol

Dissertations, Theses, and Masters Projects

No abstract provided.

Beam Dynamics In The Cebaf Superconducting Cavities, Zenghai Li

Dissertations, Theses, and Masters Projects

This work is a study of beam dynamics in the CEBAF superconducting cavities under the influence of the fields generated by externally applied RF and beam particles.;A full 3-D modeling of the CEBAF 5-cell superconducting cavity is carried out. Details of the modeling with MAFIA are discussed. Multipole fields due to the asymmetric couplers are studied by means of 3-D Fourier transforms. The cavity steering and focusing of the multipole fields are studied. Experimental measurements of these effects are performed to validate the modeling. Evaluation of the cavity misalignment is discussed. The emittance degradation effects in the CEBAF superconducting linacs …