Digital Commons Network^™

Pulse Width Modulated Adaptive Delta Modem Design And Analysis, Gregory L. Milne

Retrospective Theses and Dissertations

A unique design of a voiceband adaptive delta modem will be presented. The modulator utilizes a constant amplitude variable width pulse combined with the principles of delta modulation. This results in a modem that has lower amplitude distortion, requires less transmission channel bandwidth, and is less prone to slope overload than conventional adaptive delta modems. The design also allows the use of a simple single integration demodulator while maintaining fidelity.

The modem design and analysis is presented assuming a transmission channel which is bandwidth limited and amplitude limited.

Dynamic Systems Analysis Of A Vehicle Suspension System, Bruce M. Skeldon

Retrospective Theses and Dissertations

This research report deals with one system in a Computer Aided Instruction package in the Dynamic Systems and Control Theory fields for the college undergraduate students. It uses the computer to numerically solve the two degree of freedom equations of motion for a vehicle suspension system. Numerical solutions to the system differential equations are used to drive an animated display of the vehicle’s motion (vertical displacement and rotation about the center of gravity) on the video display terminal.

The Stress-Buffering Role Of Social Report And Self-Efficiency Among First-Year Graduate Students, Mary T. Cecchini

Retrospective Theses and Dissertations

No abstract provided.

The Relationship Between Role Conflict And Ambiguity And Types Of Communication Moderated By Organization Level, Charles A. Olsson

Retrospective Theses and Dissertations

No abstract provided.

Marital Satisfaction As A Function Of Gender, Own Rationality And Spouse's Rationality, Gabrielle T. Vincent

Retrospective Theses and Dissertations

No abstract provided.

Metalinguistic Tasks For Adolescent Children, Mary D. Griffin

Retrospective Theses and Dissertations

No abstract provided.

The Integration Of Computer Graphics With Video Disc Technology: An Application In Training, Fereidon Torkzadeh

Retrospective Theses and Dissertations

The major objective of the work outlined in this paper is to become familiar with the MOVIE.BYU graphic system from Brigham Young University to demonstrate its use in the generation of non real-time images for a typical pilot training application. The implementation is done by using the MOVIE.BYU graphics system, a VAX 11/750 digital computer, and RAMTEK 9460 system. This paper discusses how the images can be stored a frame at a time on a video disc for playback at the normal rate to portray a moving scene using a Panasonic video disc recorder and player, and a Sony video …

A Theoretical Evaluation Of Water Surface Changes In A Circular Reservoir, Hossein G. Tehrani

Retrospective Theses and Dissertations

The purpose of this project is primarily to develop an equation to estimate the time that it will take for the water surface to decrease to another depth in an inverted conical-shaped reservoir behind an earth dam by means of the falling head permeability concept. This equation can be applied to the earth embankment either with or without underdrain. Since the derived equation for time span is a complicated and tedious matter, a computer program has been developed for solving this equation.

The computer program is written in BASIC language and executed on a Tektronix 4051 microcomputer. Primary effort has …

The Effect Of Detention Period On The Clarification Efficiency Of Nitrified Activated Sludge, James C. Boyd

Retrospective Theses and Dissertations

Proper performance of the final clarifier in the activated sludge process is vital to total system efficiency. Inadequate clarification can adversely affect substrate removal efficiency due to the biochemical oxygen demand exerted by solids lost in the clarifier effluent. Detention period is one factor which influences clarification performance and thus is of interest to the designer engineer. Also of interest is the relationship between detention period and rising sludge conditions in the clarifier, which can lead to a deterioration in clarification efficiency. Rising Sludge conditions are believed to be caused by the denitrification of nitrified activated sludge in the final …

Phase-Locked Loop Based Oscillator Phase Noise Measurement Technique, Luis M. Jimenez

Retrospective Theses and Dissertations

Oscillators play an important role in the performance of various radio frequency (RF) systems. The generation of stable carrier and clock frequencies is necessary at both the transmitter and receiver ends of a communication system. Phase noise is the parameter used to characterize an oscillator frequency stability. This thesis introduces a phase noise measurement technique using a phase-locked loop. A 100 MHz Colpitt’s oscillator, for the phase noise source, was designed and built. The output of the oscillator was mixed down to 10 MHz, before a phase-locked loop extracted the phase noise information. Measurements were taken at RF frequencies using …

Optimizing Scanning Mirror System Performance Using Solid State Piezoelectric Actuators, Thomas J. Tomasetti

Retrospective Theses and Dissertations

The purpose of this thesis is to design a scanning mirror system using piezoelectric actuators. A dual-cantilevered bimorph electromechanical coupling is presented, which maximizes the amount of angular deflection possible with an applied field. Two types of feedback methods are employed: rate sensing, which provides resonance damping, and position sensing for increased bandwidth and decreased hysteresis. A prototype system, including the actuator and feedback mechanisms, is developed. Its performance compares favorably with its model and is capable of plus and minus five degrees of angular deflection with a bandwidth of 300 Hertz.

Comparison Of The Situational Checklist Versus The Skill Checklist Assessment Center Exercise Reports Forms, Donna J. Gray

Retrospective Theses and Dissertations

No abstract provided.

A Survey And Analysis Of The Beginning Teacher Program In Florida And Its Relationship To Effective Education, Joanne Mullins Olson

Retrospective Theses and Dissertations

This study was conducted to determine whether there were significant factors contributing to a teacher's ability to perform effectively in the classroom. An approximate 5% stratified random sample was selected from 9,401 possible subjects in Florida's Beginning Teacher Program between 1982 and 1985. A comparison of descriptive and reportive data was performed for teachers who completed and teachers who did not complete the program.

Statistical measures included the use of contingency tables, chi-square statistic, frequency distributions and t-tests. Results suggested that a teacher's possibility of successfully completing Florida's Beginning Teacher Program was influenced by the participant's age, grade point average, …

Perfect Numbers And Mersenne Primes, Barry A. Delello

Retrospective Theses and Dissertations

No abstract provided.

Analysis Of The Df(3r)Ok1, Pamela S. Thomas

Retrospective Theses and Dissertations

No abstract provided.

Separation Plane Priority In Computer Image Generation, Keith A. Stump

Retrospective Theses and Dissertations

Flight simulators are devices in which air crews can be trained without the use of actual aircraft. Potentially dangerous maneuvers, such as air-to-air refueling, and destructive exercises, such as evasive action from weaponry or aerial dogfights, can be practiced repeatedly with no risk to pilot or crew. Flight simulators are cost effective since the fuel costs associated with training pilots in actual aircraft can be excessive. Flight simulators offer an alternate training method with reduced cost. The task of a visual flight simulator is to present the trainee with scenes representative of those that would be seen if the actual …

The Effect Of Sewage Effluent Removal On The Water Quality Of Lake Howell, Florida, Patricia L. Smith

Retrospective Theses and Dissertations

In April, 1983, sewage effluent discharge from the Maitland and Winter Park sewage treatment plants was diverted from Lake Howell to the Iron Bridge Regional Sewage Treatment Plant. The sewage treatment plants of the cities of Winter Park and Maitland had been discharging into Lake Howell since 1927 and 1962, respectively. These point sources had contributed 95% of the total phosphorus and 69% of the total nitrogen budgets for Lake Howell. Physico-chemical parameters were monitored monthly for two years chemical parameters were monitored monthly for two years from January, 1983 through December, 1984. Annual mean values fro chlorophyll_a, …

A Performance Comparison Of Solar Radiation Predictive Models For Both Fixed And Tracking Surfaces, William F. Marion

Retrospective Theses and Dissertations

Accurate performance prediction for a system utilizing solar energy requires accurate estimates of the solar radiation received by the collector surface. This thesis compares the performance of five different diffuse solar radiation models in estimating the diffuse radiation received by a tilted surface in the warm, humid climate of Central Florida.

The following models were studied: Isotropic Model, Temps and Coulson Model, Klucher Model, Hay Model, and Perez Model. The models were evaluated for both a fixed south facing surface and for three different tracking schemes suitable for photovoltaic applications. Model estimates were then compared to the solar radiation data …

The Design And Implementation Of Surface Acoustic Wave Devices For Linear Fm And Nonlinear Fm Pulse Compression Technique For Radar Applications, James C. Walker

Retrospective Theses and Dissertations

The purpose of this work is to design, fabricate, and compare dispersive SAW devices using both linear FM and a new non-linear FM scheme. This new non-linear FM scheme uses the Blackman function as the modulating signal of the FM waveform. Up-chirped and V-chirped devices for both linear and the new non-linear FM scheme and their corresponding matched filters are compared.

Design considerations are discussed in detail. An efficient sampling algorithm (which can also be applied to other non-linearly modulated FM waveforms) developed to facilitate the design of the SAW devices is presented.

Switched-Capacitor Programmable Sallen And Key Lowpass Filters, Karl P. Eriksson

Retrospective Theses and Dissertations

This thesis deals with a different approach to switched-capacitor filters than previously seen by the use of a Sallen and Key topology. It is shown that a Sallen and Key second-order topology approach to a switched-capacitor filter gives reasonable filter performance results, contrary to what the literature leads one to expect. It is also shown that the Sallen and Key second-order topology with modification to a third-order section with buffers results in a high performance switched-capacitor filter with fewer components than previous switched-capacitor filters. This results in fewer monolithic chip size requirements, reduced power requirements, and less cost. Higher order …

A Model For Vocal Fold Vibratory Motion, Contact Area, And The Electroglottogram, D. G. Childers, D. M. Hicks, G. P. Moore, Y. A. Alsaka

Faculty Bibliography 1980s

No abstract provided.

2-Electron Wave-Functions In Hyperspherical Coordinates, Jose E. Hornos, S. W. Macdowell, C. Denise Caldwell

Faculty Bibliography 1980s

No abstract provided.

Angular-Distribution Of Fluorescence From Photoionization-Produced He+ (N=2), J. Jiménez-Mier, C. Denise Caldwell, D. L. Ederer

Faculty Bibliography 1980s

We report the first measurement of the angular distribution of the 304-Å He + ( n = 2 ) radiation following photoionization. This distribution reflects the alignment of the ion, which is related to the fraction ξ = σ ( 2 p , k d ) [ σ ( 2 p , k s ) + σ ( 2 p , k d ) ] of d component in the electron wave. The experimental angular distributions correspond to alignments of -0.62 ± 0.03 and -0.62 ± 0.02 at photon energies of 65.5 and 66.5 eV, respectively. These translate into ratios …

Individual Differences In Training Performance: The Derivation Of A Prediction Model, Brenda J. Hoskin

Retrospective Theses and Dissertations

This research examines the use of non-cognitive personality measures as supplements to traditional cognitive ability measures for predicting training performance. The Hogan Personality Inventory (HPI) significantly predicted an overall performance measure (R² = .17) for Navy BE&E Students (N = 155). However, when applied as a supplemental predictor composite to the military cognitive measure (ASVAB), the resulting increase in R² (.04) failed to attain significance, F(6, 144) = 2.17, p > .05). In further analyses, several HPI and ASVAB scales combined to significantly predict selected performance criteria. The ASVAB remained as the primary source of information. It is quite …

The Relationship Between Perceptual Learning And Psychmotor Task Variety: Contextual Interference Effects, Sherrie Ann Jones

Retrospective Theses and Dissertations

Task variety during training was manipulated to assess residual effects on skill acquisition during subsequent transfer to a novel perceptual motor task. The task involved tracing a four-point star pattern displayed on a personal computer with a "mouse," while receiving variation in visual feedback from the CRT display. Variety during training involved two cases of abnormal visual feedback (left-right reversal and 90 degree tilt) Task variety (i.e., visual feedback) was manipulated and counterbalanced in four levels: alternated variety (trial by trial), blocked variety (in five trial sets), no variety (i.e., one type of feedback), and a control condition that trained …

A Comparison Of Test Scores Obtained From Equivalent Forms Of A Multiple Choice In-Basket Exercise And A Free Response In-Basket Exercise, German B. Romero

Retrospective Theses and Dissertations

No abstract provided.

Superior-Subordinate Perceptional Congruence Of Promotion Criteria Importance And Its Relationship To Job Satisfaction, Stacie L. Clark

Retrospective Theses and Dissertations

The degree of perceptual congruence of the importance of promotion criteria to superiors and subordinates was investigated. The relationship of congruence to job satisfaction was also evaluated. Fifty-two student workers and their superiors participated in the study. Perception of promotion criteria importance was measured through the rating of a list of promotion criteria using a seven point scale. An average discrepancy score of 7.925 was obtained between superiors' and subordinates' ratings indicating a significant degree of discrepancy, t(50) = 25.04, p< .001. Job satisfaction was measured using the Job Descriptive Index (JDI) and was correlated with the discrepancy scores. Perceptual congruence of promotion criteria was found to be significantly related to subordinates' satisfaction with supervision on the job, r = -.276, p < .05, and satisfaction with present pay, r = -.299, p < .05.

Comparison Of The Narratives Vs. The Checklist Assessment Center Exercise Report Forms, James C. Rehmann

Retrospective Theses and Dissertations

No abstract provided.

The Use Of Scheffe-Equivalent Equations To Predict Physical Properties Of Neoprene, Cheng Y. Loh

Retrospective Theses and Dissertations

The goal of this study is to find a more organized and directed approach to build models for mixture systems. An attempt is made to generate and then compare Scheffe (mixture) models with those generated by McGee using the ‘conventional’ method for neoprene data. The models are judged on their ability to predict physical properties of neoprene by comparing the following: predicted and actual values by inspection; the calculated % error of prediction; the squared multiple correlation coefficients; adjusted squared multiple correlation coefficients; the Fisher statistic and significance probability. Scheffe models do not have an intercept term and test statistics …

Ion Selective Electrodes Based On Aza- Substituted Crown Ethers, Lisa Ann Wellington

Retrospective Theses and Dissertations

A cation-responsive electrode system has been developed which incorporates aza-substituted crown ethers as ligands. In a novel application, uncomplexed crown ethers were used in the pelletized form for ionic transport. Electrodes have been produced which can be conditioned for a particular ion and following their use, be reconditioned and reused for other ions. Preparation method and lifetime studies are included.

The responses of two crown ethers with plasticizers were evaluated for thirteen representative cations. The concentration range covered in each evaluation was 1 x 10^-1 to 1 x 10^-7 M. For those ions exhibiting Nernstian or near-Nernstian response, …