Engineering Commons^™

Performance Theorems For The Resource Scheduling Functions Of A Multiprocessing System, George Arthur Nicol

Dissertations and Theses

In this dissertation, a multiprocess scheduling model is developed and a set of performance theorems is constructed for the set of scheduling functions associated with the model. Each theorem describes the conditions under which a scheduling function exhibits a particular type of performance.

Photogrammetric Digitizing System, Frank Richard Gorshe

Dissertations and Theses

The acquisition of terrain data from aerial photography using digital photogrammetric methods gives the engineer and planner an economical alternative to conventional ground surveys. This paper describes a complete photogrammetric digitizing system developed for the Portland District Army Corps of Engineers. The hardware of the system consists of a

Wild AlO first order stereoplotter interfaced to an Altec AC-74 coordinate digitizer which is interfaced to both a Hewlett Packard 9810A programmable calculator and a Digi-Data nine-track magnetic tape recorder. The software of the system consists of photogrammetric routines developed for online computation by the programmable calculator and a sophisticated FORTRAN …

A Study Of The Effect Of Vibration On The Residual Stresses In A Welded Fabricated Tube, Shantini Ratnathicam

Dissertations and Theses

In many instances the predominant factor contributing to structural failure in welded parts is the residual stress which exists before the part is put into service. In this investigation an attempt is made to study the changes in residual stresses caused by vibrational stress relief (VSR). VSR is a fairly new idea in stress relief and there is no substantial evidence of its success in reducing residual stresses. This thesis documents the residual stress distributions found in 5/16 inch thick, 22 inch diameter welded fabricated tubes after VSR.

An Instrument For Determination Of The Polarization Of Fluorescence, George Irwin Johnston

Dissertations and Theses

This thesis is concerned with the development of a compact, sensitive and reliable instrument for determination of the polarization of fluorescence of fluorescein tagged molecules in solution. The instrument as designed and constructed differs from others (2,3,4,5,6,8,9). The difference is that all of its optical system is aligned on a single axis. This was accomplished by the use of an ellipsoidal mirror positioned between the excitation source and the phototube fluorescence signal receiver. In addition, the excitation source, a 45 watt tungsten-iodide light was electronically regulated to control the intensity.

Two types of determinations were made to verify the performance …

Rayleigh-Debye Scattering With Focused Laser Beams, Lee W. Casperson, Cavour W. Yeh

Electrical and Computer Engineering Faculty Publications and Presentations

A focused beam technique has been developed for diagnosing the characteristics of individual particles within a polydisperse ensemble. In the Rayleigh-Debye approximation the scattered fields are related to the orientation and properties of a scatterer by means of explicit analytic formulas. The results simplify when the particle size is small compared to the minimum beam diameter.

Metrication In Highway Design And Operations, Taher A. Al-Fadhli

Dissertations and Theses

The complex problem of metrication of highway design, construction and maintenance has been the subject of a number of studies and pilot projects carried out by the Federal Highway Administration (F.H.W.A.) of the United States and the Roads and Transportation Association of Canada. Through a research grant, the FHWA of the U.S.A. assigned the Ohio Department of Transportation, the Illinois Department of Transportation and the Oregon Highway Division to design, construct, and maintain these metric projects. The author has reviewed the experience and conclusions of these studies and the problems encountered in the pilot projects relative to the design, survey, …

An Experimental Investigation Of The Hole-Drilling Technique For Measuring Residual Stresses In Welded Fabricated Steel Tubes, Chau Mong Tran

Dissertations and Theses

Among semi-destructive methods of measuring residual stresses in elastic materials, the blind hole-drilling strain-gage method is one of the best because it is simple, economical and accurate. It is based on the measurement of strains disturbed by machining a small diameter shallow hole in the test piece. The strains measured in three known directions permit the determination of the direction and magnitude of principal stresses and subsequently of any stress in any direction.

This thesis presents the investigation of residual stresses in the longitudinal direction of a welded fabricated steel tube of 22 inch diameter, relating to a series of …

An Investigation Into The Elasticity Of Demand For Motor Gasoline, Samy Fouad El-Iskandarany

Dissertations and Theses

This thesis investigates the existence and determinants of the elasticity of demand for motor gasoline.

The research can be divided into four main stages. In the first stage, time series data of fifteen member countries of the Organization for Economic Cooperation and Development (OECD) are analyzed.

The ratio of gasoline price per gallon to the per capita GNP is introduced in this research to explain the variability in the size of the price elasticities of demand over the various countries. The ratio is called the "Price Factor" and designated as P.F. The introduction of P.F. established the basis for meaningful …

Light Extinction In Polydisperse Particulate Systems, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Analytic methods are developed for determining the attenuation characteristics of light beams propagating through ensembles of scattering particles including those with complex index of refraction. The methods are applicable to a wide range of practical particulate systems, and the results are expressed explicitly in terms of elementary functions. Propagation through fog and clouds is considered as an example, and it is found that absorption by the liquid lengths. water in such ensembles affects strongly the extinction for ir wave-lengths

Assessment Of Feasibility Of Proposed Bolted Connections For Tubular Structures, John Henry Tausch

Dissertations and Theses

The search for new and additional sources of energy -- from sun, wind, waves, and ocean currents -- is necessitating the development of structures in the open environment of the oceans as well as on land. The advantages of round or tubular members for use in such structures are shown; and to avoid the uncertainties of welded joints, two bolted connections are proposed and their feasibility explored.

The Development And Testing Of A Fluidic/Pneumatic Position Servo, David Lyle Portin

Dissertations and Theses

This thesis reviews the design and analysis of a fluidic/pneumatic position servo. Rolling diaphragm piston actuators are used for the system drive, and a hydrostatic gas journal bearing is used as the position sensor. The servo has a 1 inch range which is monitored using an electrical capacitive position transducer that was built as an integral part of the system.

Open-loop frequency response testing provides the basis for a mathematical model of the system.

The servo response is linear at frequencies up to 3 Hertz.

The frequency response appeared to be limited by the design of the gas bearing sensor, …

Error Codes In Digital Data Communication Systems, Robert Hadley Cravens

Dissertations and Theses

Today’s digital communication systems perform data transfers at the rate of millions of bits per minute, with data errors in the order of 1/6th error per day. This magnitude of errorless communication is now possible because of sophisticated error correcting codes. Many types of error codes are employed today in three distinct areas of digital data communication: human to computer; data source to computer; computer to computer; and intra-computer; we are concerned here with intra-computer communication.

This research is primarily a mathematical study of error codes in general to explore the possibilities of each major type for the purpose of …

Limit Design Of Unbraced Reinforced Concrete Frames, Thomas Joseph Gavin

Dissertations and Theses

The main objective of this study was to determine whether Limit Design could be applied to low-rise unbraced concrete frames. The investigation was carried out both analytically and experimentally.

In the analytical part, two mathematical models were used to determine the behavior of unbraced frames. The first method used a nonlinear computer program, which takes into account the material and geometric nonlinearities of concrete frames. Several cases of frames with different reinforcement ratios and under different beam to column load ratios were investigated. For each frame the gravity loads were increased proportionately to 3/4 of the ultimate frame capacity. Then, …

An Experimental Investigation Of Unbraced Reinforced Concrete Frames, Nourollah Samiee Nejad

Dissertations and Theses

The main objective of this investigation is to study experimentally the behavior of rectangular reinforced concrete frames subject to a combination of low column loads, beam loads, and lateral load. The analytical tool used in this investigation is a computer program which is a generalized computational method for non linear force deformation relationship and secondary forces due to displacement of the joints during loading.

In the experimental portion of this investigation, two rectangular frames, one design by the Ultimate Strength Design method and the other by a Limit Design method were prepared and tested to failure with short time loading. …

Single Particle Scattering With Focused Laser Beams, Lee W. Casperson, Cavour W. Yeh

Electrical and Computer Engineering Faculty Publications and Presentations

A scattering technique is described in which the incident laser beam is tightly focused to isolate the effects of a single particle. In this way the individual particles may be studied in their natural environment, and experiments with latex spheres are in agreement with the theory.

Threshold Characteristics Of Mirrorless Lasers, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Detailed analytical expressions are developed for the output power and spectral characteristics of high‐gain mirrorless laser amplifiers. With regard to intensity variations and spectral narrowing, such lasers are similar in behavior to conventional laser oscillators. A threshold transition region is apparent as saturation sets in, and spectral rebroadening occurs in inhomogeneously broadened laser systems. These solutions take full account of saturation by both the right and left propagating radiation, and the results agree with experiments that have been reported.

Design Of A Microprocessor Controlled Telecommunication System, George J. Maroutsos

Dissertations and Theses

Recent advancements in Large Scale Integration Technology have made available devices, such as microprocessors, analog gates and "three state" logic, that provide the designer with a wide range of possibilities in the design of telecommunication systems. A microprocessor and analog gates are utilized in this design to demonstrate the feasibility of implementing a flexible Telecommunication System. The microprocessor is programmed to control, through software, the system functions. The feasibility of systems highly adaptable to the needs of individual subscribers is thus demonstrated.

Beam Modes In Complex Lenslike Media And Resonators, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

General sets of higher-order beam modes are derived for light propagation in media having spatial variations of the gain or loss. The resulting expressions are also valid for propagation through conventional optical elements and graded transmission filters. The four basic mode sets obtained include off-axis Hermite-Gaussian and Laguerre-Gaussian modes of both real and complex argument. A procedure is developed for finding the resonant modes of laser oscillators containing arbitrary complex lens elements, and the mode stability properties of lasers can be interpreted physically by means of these formulas.

A Numerical Solution For The Ultimate Strength Of Tubular Beam-Columns, Arnold L. Wagner

Dissertations and Theses

To provide a basis for the development of interaction curves for tubular beam-columns of annular cross section, a general purpose beam-column computer program is developed, and used to determine ultimate load capacities. The paper presents the analytical model and the computer method. The analytical results are compared with published test data as well as experimental data obtained as part of this project.

Pulse Evolution In Co₂ Lasers, Lee W. Casperson, M. J. Herbst, John J. Turechek

Electrical and Computer Engineering Faculty Publications and Presentations

Explicit formulas are examined for the development of optical pulses in gain‐switched or Q‐switched laser oscillators and for the distortion of such pulses in succeeding stages of laser amplification. The results are compared to data obtained with a TEA CO₂ oscillator‐amplifier system.

Analytic Modeling Of Gain‐Switched Lasers. Ii. Laser Amplifiers, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The pulse transfer characteristics of gain‐switched laser amplifiers are investigated analytically. New closed‐form solutions have been obtained including arbitrary space‐ and time‐dependent pump distributions. The general results are specialzied to the important cases of uniform and traveling‐wave excitation. Input‐pulse shapes considered include step functions, practial oscillator output pulses, and also the inherent spontaneous‐emission noise. The results lead to improved models for pulse amplifiers and mirrorless traveling‐wave lasers. By proper choice of pump characteristics arbitrary output‐pulse waveforms can be synthesized.

Analytic Modeling Of Gain‐Switched Lasers. I. Laser Oscillators, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Detailed mathematical models are derived for the evolution of light pulses in gain‐switched laser oscillators. Unlike previous instantaneous‐switching models, arbitrary pump and spontaneous relaxation rates are considered. Explicit expressions are obtained for the gain and pulse characteristics in several practical situations, and both homogeneous and inhomogeneous limits are considered. By proper adjustment of the laser pump any output‐pulse shape can be obtained. The results are especially relevant for recent short‐pulse ultraviolet lasers and also for more conventional devices such as TEA CO₂ lasers.

A Study On The Stabilization Of A Floating Platform, Waldo Lizcano

Dissertations and Theses

A new technique for controlling the pitching motion of a floating platform is proposed in this study.

The floating platform is assumed to be a simplified model of the columnar type rectangular platform supported by buoyant force from four cylindrical legs. The control arrangement consists of water jet streams immerging horizontally from two points located some distance apart on each leg to form a restoring couple. The water jet streams can be shifted t0 opposite horizontal positions or to the vertical downward ,positions according to control requirements. They are governed by angle control criterion as well as velocity control criterion. …

The Analysis Of The Deflection And Containment Of A Hot Plume By Side Draft Exhaust Hooding, Douglas H. Macgowan

Dissertations and Theses

A common industrial ventilation and pollution problem results when a thermally buoyant polluted plume of air must be exhausted away from a work area to allow achievement of air pollution standards. Generally, a close fitting canopy hood is one of the most effective means of exhaust containment; however, physical restrictions or the operation itself often prevent such an arrangement, and a hood located to the side of the operation is required. This arrangement requires the exhaust to bend and contain the vertically rising plume with a horizontal sweep of exhaust air across the surface of the operation.

A review of …

Evaluation Of The Institute Of Transportation Engineers Program For School Pedestrian Crossing, Nabil Shafiq Hamadeh

Dissertations and Theses

The Technical Council of the Institute of Transportation Engineers (ITE) developed a program for school crossing protection. The intent of this thesis is to evaluate the ITE program within. the context of those programs developed by other agencies throughout the nation. Research materials were obtained from the appropriate Federal, state, local and other agencies through papers, articles, reports and correspondence. Upon the analysis of these sources, the ITE program was found to be deficient in several ways. Recommendations for modifying the program which are set forth herein include a revision of the ITE program including the school route map, clarification …

Bayesian Inquiry: An Approach To The Use Of Experts, King G. Yee

Dissertations and Theses

Subjective information is a valuable resource; however, decisionmakers often ignore it because of difficulties in eliciting it from assessors. This thesis is on Bayesian inquiry and it presents an approach to eliciting subjective information from assessors. Based on the concepts of cascaded inference and Bayesian statistics, the approach is designed to reveal to the decision-maker the way in which the assessor considers his options and the reasons he has for selecting particular alternatives. Unlike previous works on cascaded inferences, the approach here focuses on incoherency. Specifically, it employs the use of additional information to revise and check the estimates. The …

The Design Of An Automatic Electronic Preanodizer, Armen C. Grossenbacher

Dissertations and Theses

The topic of this thesis is the design of an automatic preanodizer to be used to preadjust precision tantalum resistors by anodizing their surfaces. The purpose of the preanodizer is to generate a controllable voltage ramp to be applied to a set of tantalum resistors which are immersed in a suitable electrolyte. The slope and maximum value of the voltage ramp are set to produce the current required for proper anodization of the resistors. The rate of anodization determines the rate of change of the resistor value. This thesis covers the design of an electronic device to meet a set …

Threshold Characteristics Of Multimode Laser Oscillators, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The oscillation characteristics of a multimode laser are considered in detail, and for the first time saturation by all of the cavity modes is included. Analytical expressions are obtained for the mode amplitudes, linewidths, and over‐all spectral characteristics of lasers operating above and below threshold. It is found that with increasing excitation the spontaneous emission spectrum is gradually resolved into a set of narrow discrete modes. Slightly above threshold the number of modes reduces in a homogeneoulsy broadened laser until only a single mode is oscillating strongly. The theoretical results are in agreement with experimental data that have been reported …

Mode Properties Of Annular Gain Lasers, Lee W. Casperson, Mohammad Shabbir Shekhani

Electrical and Computer Engineering Faculty Publications and Presentations

The properties of a new class of laser resonators are investigated theoretically and experimentally. In these lasers the radiation propagates longitudinally in an annular amplifying medium, and useful low loss modes can be obtained even when the axial region is obscured. Alignment characteristics and far field patterns are discussed, and experiments have been conducted using coaxial double-discharge CO₂ devices.

Computer Aided Design For Fluidic Sequential Circuits Of Fundamental Mode, Yau-Hwang Lee

Dissertations and Theses

This thesis presents the method of state diagram synthesis and the development of a computer program for designing fluidic sequential feedback control circuits of the fundamental mode. A paper on state diagram synthesis was authored by Chen and Lee, presented in Detroit and published as ASME paper 73-WA/Flcs-2 in 1973.

Hypothetical systems are illustrated by using series of events characterized by the piston positions of some double-acting pneumatic cylinders. In these systems , an action can only begin when the previous action has been completed. Every extension or retraction of a piston is memorized and manifested by a flip-flop element …