Engineering Commons^™

Design Criteria Of Coherent Optical Fiber Communication System, Rajesh N. Patel

Theses

Design criteria of coherent optical fiber communication system were discussed and investigated. First, the different types of optical fibers (waveguides) were discussed. Then the laser sources, photo-detectors, transmitter & receiver circuits were discussed in detail.

Design criteria of conventional intensity modulated (direct detection) optical fiber communication system were discussed. Then, the design criteria and estimation of number of photons for different modulation schemes for coherent optical fiber communication system were analyzed.

Coherent optical fiber communication system's advantages and drawbacks were discussed in detail. Improvement in receiver sensitivity of coherent detection compare with conventional direct detection was investigated. Finally, some receiver …

Image Enhancement And Edge Detection Using Fuzzy Algorithm, Samir Patel

Theses

A method of image enhancement and edge detection by computer using the fuzzy set is illustrated. The algorithm involves extraction of fuzzy properties corresponding to pixels and then succesive application of fuzzy operator 'contrast intensification' along with smoothing in the fuzzy property plane before detecting its edges. The property plane is extracted from the spatial domain using S, π, and (1- π) functions and the fuzzifiers. Edge detection is achieved using KIRSH operator. A computer routine is developed and the effectiveness of the algorithm with different value of the system parameter is demonstrated on different images. The digital computer HP …

Design And Construction Of A Thermoelectric Calorimeter To Measure Thermal Resistance Of Building Components, Ravindra Samtaney

Theses

The steady-state thermal resistance of a building wall is an important parameter in determining its thermal performance. In-situ measurement of thermal resistance is the only unambiguous way of determining thermal resistance since the actual value may significantly differ from the laboratory or the calculated R-value.

Hitherto, the in-situ measurement of thermal resistance has been largely confined to the winter season. A thermoelectric calorimeter was designed, constructed and tested in order to provide measurements of thermal resistance during the summer as well as the winter season.

This thermoelectric calorimeter is a rectangular box, insulated on five sides and covered with an …

Design Of An Experimental Apparatus To Measure The Charge And Mass Of Ionized Species In A Partially Ionized Cluster Beam Deposition System, Nitin K. Shah

Theses

The objective of this research was the design and construction of an experimental apparatus to investigate the size distribution of gallium clusters that can be emitted from a heated crucible with a 1 mm nozzle. This research work involved the design and construction of a partially ionized cluster beam (PICB) deposition system which would provide low charged particle background for retarding field analysis and cluster size measurements. The apparatus also allowed control of critical parameters on which the cluster size may depend.

The promise of PICB is based on the formation of clusters of adatoms, their ionization and their acceleration …

Investigation Of High Shear-Rate Viscoelastic Flow, Sudarshan S. Sood

Theses

The object of this study is to understand two important characteristics exhibited by viscoelastic fluids at high shear-rates, and analyse their influence on practical applications Viscoelastic fluids, such as polymer solutions, when subjected to high shear stress, behave in a manner which has not been sufficiently analytically explained In experimental studies, such fluids have shown.

(a) Stress relaxation.

(b) Decrease of viscosity with an increase in shear rate.

(c) Slight decrease of viscosity with temperature.

(d) Normal stress differences in shear flow.

In this thesis an analytical explanation is given for two (a and b ) of these features This …

Friedman's Model Of Calculating The Optimum Bid Price Using Dbase Iii Plus, Selim Uzel

Theses

The micro-computer program, BIDCALC presented in this thesis is offered as simple, practical, and proven approach to developing an effective data-based competitive bidding strategy. BIDCALC is written in dBASE III Plus programming language for MS-DOS based computers.

Main purpose of the program is to evaluate the optimum bid using the Friedman's model of Maximizing the Expected Profit. At the same time the program keeps track of necessary competitor and project information in data base files which are easily transferable to other software packages. The program is capable of generating a variety of reports in a matter of seconds.

BIDCALC is …

Automatic Generation Of Robot Paths For Waterjet Cutting From Autocad Drawings, Samir Vij

Theses

The automatic generation of robot paths for a commercial water-jet cutting system by establishing a link with a commercial CAD system, in an attempt to achieve paper-less manufacturing and to minimize human interface is the objective of this thesis.

Water-jet cutting is an emerging technology with unlimited potential for a wide variety of manufacturing applications. Water-jet cutting systems integrated with robotic work cells allow the user to cut a variety of parts through part programs generated for robot controllers. The system employed is an Ingersoll-Rand water-jet cutting system, the movement of which is controlled by an Allen-Bradley 8200R programmable robot …

Investigation Of The Characteristics Of The Kerf And The Surface Generated In The Course Of Cutting Titanium With Abrasive Waterjets, Ajay Vora

Theses

The effect of cutting parameters on the quality of cut in the course of cutting Titanium (Gr.2) with Abrasive Waterjet is investigated. The cutting parameters include nozzle traverse rate, size and feed rate of abrasives and nozzle(s) diameter. The width of kerf (top and bottom ), taper and roughness is studied. The measurements are tabulated and plots are made to study the trend and relationship for each set of parameters.

The qualitative conclusions are made successfully but no quantitative relationship was derived. Suggestions are made for the evaluation of technology for feasibility and economic justification, and to achieve desired cutting …

Rf Characterization Of A Directly Modulated Ingaasp Buried Heterostructure Laser Diode, Charlotte Alvarez

Theses

The use of fiber optics for the transmission of microwave signals had its beginnings in 1984. Applications were limited to the lower microwave frequency regions. Technology in this field is advancing rapidly due to the high demand driven by the telecommunications community for high speed digital applications. Extensive research and development efforts are underway by both the component manufacturers and the subsystem end user. Most of the near term applications of microwaves in fiber optics are in weapon systems and communication systems for military and other government agencies.

The high frequency modulation characteristics of Lytel's InGaAsP 1300 nm buried heterostructure …

Design Of Bridge Inter-Connecting Token Ring & Token Bus Local Area Networks, Kasinath Anupindi

Theses

A Bridge interconnecting two Local Area Networks has been modelled. The two interconnected networks are the Token Ring and the Token Bus LANs. Concepts of Queueing theory have been employed in the design. Initially it is assumed that the buffer size at the Bridge is infinite. Further it is assumed that the arrival rate of the messages is Markovian and the service rate is General, Le it is an M/G/1 system. Expressions for the average waiting time at the Bridge and the size of the buffers is computed. Graphs for various parameters have been plotted. Based on these graphs the …

A 3-D Tactile Sensor With Digital Output, Sin-Shou Cho

Theses

This thesis details the design of a new tactile sensor for general-purpose robot manipulators. Such manipulators, designed to be functionally equivalent to the human hand, will require sensor arrays that fulfill several requirements : (1) many sensor elements to minimize tactile imaging time, (2) close spacing of small sensing elements for fine spatial discrimination, (3) ability to be molded to a convex fingertip surface for taction on concave surfaces, (4) tolerance to over-scale forces without damage. In addition to the above, which are considered requirements, several other characteristics are desirable. Foremost is the ability to sense shear forces, which provide …

Estimation Of Modified Proctor Densities Based On Visual Identification, Ramesh Damodaram

Theses

Often in construction jobs requiring controlled compaction, there is a delay involved in testing the soil sample to be used as a structural fill. Here a rational approach has been adopted to get these values from 600 test data available. Using these data, appropriate relationships between grain sizes, maximum dry densities and optimum moisture content were developed. From these, two tables were derived to estimate the maximum dry density and optimum moisture content based on grain size distribution.

In a fill control job, if the borrow pit happens to change, the field personnel could obtain soil samples and send them …

Implementation Of The Voice Processing System, Yang-Young Dan

Theses

The Voice Processing System is implemented by using XILINX Advanced Computer Aided Design Technology. It is also used as an interface to the 8052 AH-BASIC single hoard computer system.

The Voice Processing System ( VPS ) comprises three major parts:

1. Voice Detection Circuit

2. System Clock Generation & Synchronization

3. Signal Processing and Storing Circuit

The analog voice sip!gnals are the inputs to the first part of VPS. The digitalized voice is the output of this system.

In order to get precise output, the first part plays the roles of noise cancellation, zero crossing processing, and recognition.

For the …

Two Domain Heat Transfer Studies Using A Coupled Finite-Difference And Boundary Element Programs, Serap Dikmenli

Theses

An iterative coupling of a finite-difference boundary layer code "STAN5"' and a boundary element code "BEASY"2 have been used to study two dimensional convective-conductive problems. The coupling method essentially leaves undisturbed the codes of these programs and uses their custom features in their applicable domains. The boundary layer program is used-in the convective domain, while "BEASY" is used in the solid domain. Compatability conditions are established between these domain solutions and an iterative scheme is used until these conditions are mutually satisfied.

The indirect communication of compatability (boundary) criteria between these programs was achieved by two editor/data-transferor like programs. Combined …

Stepping Motor Control And Position Monitoring, Pei-Kuan Feng

Theses

Stepping motors provide precise digital control of speed, without speed detector feedback. A stepping motor can produce a large torque for a relatively small displacement, without a shaft-position sensor or special compensation. This provides accurate control of motor position. This thesis describes the development of stepping motor torque characteristics and the different approaches stepping motor phase current waveform detection. It is shown that one of the most useful indicators of rotor position is the initial rate of current rise. The Hybrid, Permanent-magnet and Variable-reluctance step motors have been applied in the drive circuits. The open-loop control circuits are implemented to …

The Tapered Dielectric Rod-Conical Antenna, Nicholas I. Georghiades

Theses

The problem of the linearly tapered dielectric rod/conical antenna, excited by the HEI1 hybrid mode in a metallic circular waveguide , is rigorously studied. A theoretical model, and numerical investigation for the radiation characteristics of such an antenna are presented. The model is based on the combination of classical analysis of the Electromagnetic Fields within the dielectric rod, Local Mode Theory, and the Equivalence Principle for the determination of equivalent current distributions.

The far-zone radiation field is considered to be the summation of the fields produced by two radiative components in the dielectric rod/conical structure: The "aperture" of the uniform …

Microcomputer-Controlled Respiratory Rate Monitor, David John Hartmann

Theses

In order to measure the metabolic change in an animal due to the administration of anti-obesity drugs, an instrument was constructed which will allow the continuous sampling of twelve individual animals residing in enclosed chambers. The instrument is based on the principle of Indirect Calorimetry, which measures metabolic rate by sampling the inlet and outlet concentrations of respiratory gases (oxygen and carbon dioxide) of the chamber. The system is controlled by an IBM PC which will control six chambers or twelve chambers simultaneously.

The system assesses the metabolic rate of the animal by calculating the Respiratory Quotient (RQ) and the …

A Computer-Based Microwave Interferometer Instrumentation System As A Non-Invasive Cardiopulmonary Monitor, Chin-Yee Eric Ho

Theses

The system comprises a microwave interferometer as a computer-based non-invasive cardiopulmonary monitor. The microwave interferometer records the mechanical vibration of the chest wall. The objective is to determine whether the signals may have diagnostic value and to evaluate the instrument as a non-invasive and non-contacting cardiopulmonary monitor.

With the help of a computer it is possible to analyze the mechanical vibration of the chest wall produced by the heart and thereby detect, and possibly categorize, cardiac abnormalities. This system is able to process two channels, the first signal from microwave interferometer records chest wall vibrations and the second signal is …

Role Of Contact Stresses In Surface Fatigue And Wear, Chih-Chi Huang

Theses

This thesis is devoted to the role and analysis of stress distribution at the area of load and slide contact in the surface fatigue. The orthogonal shear stresses are critical stresses for surface fatigue in pure rolling contact. On sliding combination with rolling, the maximum shear stresses become to be the prime cause for surface fatigue because they move from subsurface toward the surface. The compressive residual stress induced during manufacturing could increase the resistance to surface fatigue. Sliding speed rarely affects the stress distribution and surface fatigue. From investigation of the stick-slip region in the contact area, sliding wear …

Reliability Of Packaging In Microcircuits, Zia Iqbal

Theses

The semiconductor industry is faced with the problems of how to increase the level of reliability of semiconductor parts being used in the electronic systems which have had their lifetimes extended through new and better system design.

This paper deals with the reliability of packaging constructions commonly used in large scale integration / integrated circuits and will present the failure mechanisms and failure modes which can arise when proper processing is used. In addition, the materials used in each construction and how they affect reliabilty will be analyzed.

It is not the intention of this paper to present any new, …

Determination Of Project Duration For Resource Constrained Projects Without Using Resource Scheduling Procedure, Rabindra Nath Karmakar

Theses

The problem addressed in this thesis is that of determining the practicability of equating measures of network and resource characteristics to the early finish date of a project which is constrained by resources. The output of standard critical path calculations along with information on resource profiles that are easy to calculate can be of use in estimating resource constrained project duration.

Twenty two different equations ( developed by Hall) were used to find the estimated project finish dates. These results were compared to the schedule resulting from the application of the heuristic rule of minimum activity float. It is shown …

Schema Based Wiring Tool : A Computer Network And Cad Design System, Jia Jing Zhang

Theses

For the purpose of building a SBC-8052-Basic micro-controller based instrument system, a new SCHEMA II Computer Aided Design system for IBM-PC is used to enhance circuits design routine, and it is described here. The new features of this CAD are discussed, and the design example of a new version of the SBC-8052-Basic micro-controller is given here in detail.

Since the wiring board system is adopted as tool of the laboratory development and controlled by the QL microcomputer, and since SCHEMA II CAD, on the other hand, is used on the IBM-PC-AT, communication between the two microcomputers is accomplished, and the …

Softening Response Of Concrete In Direct Tension, Teresa Cintora

Theses

Due to the increased attention in nonlinear fracture mechanics and numerical methods of cementitious material, it has become necessary to have a reliable investigation of the post-peak softening response of concrete under direct uniaxial loading. But due to the brittleness of the material previous researchers have encountered great difficulty in obtaining complete data regarding the load-deformation behavior. This study uses a strain-controlled testing method and therefore the post-peak curve can be more easily obtained. Based on these results a unique formula for the normalized load vs. deformation curve has been proposed to be applied in fracture analysis applications.

Study Of The Structure And Capacity Of Construction Industry In Pakistan, Tayyab A. Ansari

Theses

The construction industry is the second largest sector in Pakistan's economy after agriculture. It is a fragmented industry which includes very small and very large contracting groups. It includes professional groups such as architects, engineers, management personnel etc. Major part of this industry is dominated by material's suppliers, vendors etc.

In the light of the developments which have taken place particularly over the last ten years, the study has covered the capacity of the construction industry in terms of estimated output, availability of manpower, demand and production of building materials , financial problems, credit, quality of work, the role of …

A Dynamic Model Of A Fill-And-Draw Reactor And Its Implications For Hazardous Waste Treatment, Shing-Hwa Chang

Theses

A dynamic model of a fill-and-draw reactor has been developed, which includes a number of operational parameters such as the draw-down volume, the fraction of total cycle time devoted to fill, reaction, and draw, and the concentration of the toxic substance in the feed to the reactor. The model has been solved numerically for two cases, one assuming Monod kinetics, and one considering substrate inhibition (Andrews kinetics).

The conversions achieved with this type of reactor have been compared to that of a conventional activated sludge (CSTR) design. These results indicate that for most practical settings of the operating parameters, the …

An Improved Method Of Gas Chromatographic Determination Of Trace Organic Vapors In Ambient Air Collected In Canisters, Yong-Jin Shen

Theses

An improved method for analysis and quantitation of volatile organic compounds in ambient air has been developed. Samples are collected in evacuated SUMMA polished stainless steel canisters using a sampling flow apparatus with a critical orifice as flowrate controller. Analysis of VOCs in the collected air is carried out by cryogenically concentrating the sample, then thermally transfering it onto the head of a capillary column in a gas chromatograph. The column effluent is measured by a parallel flame ionization detector (FID), and electron capture detector (ECD). The problems associating with quantitative transfer of the sample to the initial cryofocusing loop …

Temperature Dependent Reliability Of Plastic Packaged Microcircuits, Wasim Ahmed

Theses

Increasing power and power densities in new high complexity semiconductor devices are creating heat removal problems. Increased powers produce higher junction temperature which lead to potentially faster degradation of device reliability. Thermal management at device level packaging involves efficient and cost-effective removal of dissipated thermal energy from the device to assure its reliable performance over the long term. In the context of very high levels of integeration of future ICs, thermal management will mean making such devices possible close to the limits of acceptable high temperature.

The major factors affecting heat flow in a plastic Dual-in-line-packages (DIP'S) are investigated using …

An Investigation Of Interrupt Handling Schemes In Pipeline Processors, Shailesh Ratilal Gami

Theses

In order to acheive higher performance in a pipeline processor, proper interrupt handling is essential. In a pipeline processor, interrupt handling is difficult because many instructions are in the processor at the same time. This study describes and evaluates the different solutions to interrupt handling. Several pipelined 32-bit microprocessors have also been studied and their architectural and programming features are compared.

Performance Of Single Dwell Serial Synchronization System, Chan-Yee Hsiung

Theses

By using the sampling theorem, the problem of the detection of a signal in white Gaussian noise, reduces to the consideration of the sum of the squares of statistically independent Gaussian variates. If the transmitter and and receiver are not synchronous, then no data transmission is possible and the decision statistic has a central chi-square distribution. Otherwise, the decision statistic has a non-central chi-square distribution. Also, this. paper presents a method to calculate the mean and variance of the acquisition time which are the most important parameters to evaluate the performance of a PN spread synchronization system. In addition, the …

Failure Mechanisms Of Hermetically Sealed Solid Tantalum Capacitors, Syed R. Kazmi

Theses

This study has determined the failure mechanisms of solid tantalum capacitors and their causes. It was observed that high leakage current and electric shorts are the most prominant modes of failure. The experimental data has proved that humidity and high temperature are the factors which promote these kinds of failures. It is also stablished that change in electrical parameters due to exposure to harsh weather are reversible. Vacuum treatment to such capacitors helped in improving their electrical characteristics.