Digital Commons Network^™

Factors Influencing Recruitment Of Collegiate Basketball Players In Institutions Of Higher Education In The Upper Midwest, Lori Ulferts

Theses and Dissertations

The purpose of the study was to examine the factors that influenced college basketball players to choose to attend a certain institution of higher education. The secondary purpose was to learn if the perceptions of head college basketball coaches as to reasons for student athletes to choose a college were the same as the student athletes' stated reasons. The study sought to determine what factors influence athletes' decisions and whether those factors differed for female and male athletes, female and male coaches, athletes from different divisions, and coaches from different divisions. The study was intended to contribute to knowledge in …

Nonlinear Large Displacement And Moderate Rotational Characteristics Of Composite Beams Incorporating Transverse Shear Strain, Stephen G. Creaghan

Theses and Dissertations

This research was directed toward the investigation of nonlinear large displacements and moderate rotations of composite beam structures considering a finite element potential energy approach incorporating through the thickness shear strain as an analytical function. This approach was compared to large rotation theories. Test cases were run to evaluate numerical algorithms Riks method and displacement imposed techniques were employed. The limitations and advantages of both methods were considered. Loading arrangements included concentrated forces as well as moments.

An Electromagnetically-Controlled Precision Orbital Tracking Vehicle (Potv), Richard E. Lawrence Jr.

Theses and Dissertations

A propulsion configuration it defined for a precision orbital tracking vehicle (POTV) that employs electrodynamic forces to control vehicle attitude and position with respect to another spacecraft. A pair of electrically powered thrusters assist the POTV in position control. The vehicle can maintain continuous standoff at close range from another spacecraft in any direction, has docking capability, and has gross orbital transfer capability. These capabilities and the specific design derived for the POTV have been defined by the requirements of a postulated space facility (ASSET) that salvages structural aluminum from the external fuel tank of the space shuttle. Precision control …

A Synthetic Environment For Satellite Modeling And Satellite Orbital Motion, David L. Pond

Theses and Dissertations

Analysts tasked to study satellites moving in space must often rely on photographs to conduct their analysis. Often these photographs do not adequately represent how satellites move in space, their spatial relationships, or their interaction with other satellites. What analysts need is a three- dimensional synthetic environment that depicts satellites as they actually move and interact in space. This thesis addresses the early development of the Satellite Modeler (SM), a system that allows analysts to study, satellite motion and maneuvering of computer aided design (CAD) models of those satellites in a three-dimensional orbit. The system contains equipment that allows analysts …

An Object-Oriented Computer Aided Design Program For Modern Control Systems Analysis, Frederick L. Trevino

Theses and Dissertations

This investigation is a continuation of the ICECAP-PC research project conducted under Prof. Gary B. Lamont at the Air Force Institute of Technology. It is an ongoing development of a public domain Computer Aided Design (CAD) package for Control Engineering students and faculty, with a special emphasis on education. This investigation focuses on three areas. First, an object-oriented environment is specified, designed and implemented. The functional structure of ICECAP-PC is then converted into an object-oriented structure because object-orientation provides an advanced logic and implementation structure and effectively addresses common software engineering issues. Additionally, a new interface featuring pull-down menus, mouse …

Optical Haar Wavelet Transforms Using Computer Generated Holography, Peter G. Block

Theses and Dissertations

This research introduces an optical implementation of the continuous wavelet transform to filter images. The wavelet transform is modeled as a correlation process and is implemented with a Vander Lugt correlator. The orthonormal basis set used is composed of two one-dimensional Haar functions and a two-dimensional Haar function. Each wavelet, as well as its first two dyadic scalings, is implemented with computer generated holography. The Interferogram method, which represents a function only in terms of its phase, is used to encode the wavelet functions. The results are imaged onto a CCD array and captured using a framegrabber. The optical results …

Cathodoluminescence Spectroscopy Of Zinc Germanium Phosphide Zngep2, Michael R. Gregg

Theses and Dissertations

Zinc Germanium Phosphide (ZnGeP₂) is a nonlinear semiconductor suitable for use as a laser tuning element over the two to six micron wavelength range. Although this crystal has been studied in the past, its luminescent properties are not yet well understood. In this present study, ZnGeP₂ has been examined using cathodoluminescence spectroscopy (CL). Specifically, the spectral dependence of the CL was obtained as a function of electron beam energy, beam current and temperature. The resulting CL was found to be polarized with a peak structure that was dependent on the polarization. This peak structure observed by CL …

An Approximate Solution For The Linearized Spinup Dynamics Of A Dual-Spin Spacecraft, David L. Kinney

Theses and Dissertations

An approximate solution is obtained for the linearized equations of motion for the spinup dynamics of a dual-spin spacecraft. The approximation is obtained from the WKB (Wentzel, Kramers, and Brillouin) method, which usually generates a divergent series. Comparison between the WKB solution and the numerically integrated solution are used to study the effects of spinup torque magnitude and the number of WKB terms used on the accuracy of the approximation. The WKB method generates accurate approximations for small spinup torques using as few as two terms in the series when no singularities are present in the WKB terms during the …

Behavior Of A Titanium Matrix Composite Under Quasi-Static Tensile And Compressive Loading, Keith L. Bearden

Theses and Dissertations

Quasi-Static tensile and compressive testing was performed on a unidirectional titanium matrix composite. The specific material was SCS-9/β 21S. The initial tensile and compressive modulus for both laminates was the same. The ninety degree laminate had a tensile and compressive modulus of 115.89 GPa. The zero degree laminate had a tensile and compressive modulus of 197.51 GPa. The ninety degree laminate exhibited a three stage stress/strain response in tension. The first stage is completely linearly elastic, however, partial debonding of the fiber from the matrix was observed. This partial debased did not effect the stress/strain response. The second stage is …

Behavior Of A Quasi-Isotropic Ply Metal Matrix Composite Under Thermo-Mechanical And Isothermal Fatigue Loading, Karl A. Hart

Theses and Dissertations

This study investigated the behavior of the SCS6/Ti-15-3 metal matrix composite with a quasi-isotropic layup when tested under static and fatigue conditions. Specimens were subjected to in-phase and out-of-phase thermo- mechanical and isothermal fatigue loading. In-phase and isothermal loading produced a fiber dominated failure while the out-of-phase loading produced a matrix dominated failure. Also, fiber domination in all three profiles was present at higher maximum applied loads and al three profiles demonstrated matrix domination at lower maximum applied loads. Thus, failure is both profile dependent and load equipment. Additional analyses, using laminated plate theory, Halpin-Tsai equations, METCAN, and the Linear …

Development Of An Engine/Airframe Performance Matching Scheme For Jet Engine Retrofit, Alan Lach

Theses and Dissertations

This investigation developed a procedure and new analysis tools for identifying retrofit engine designs for use in existing airframes. The goal was to find a replacement engine for the air-to-air fighter, AAF, developed in the textbook Aircraft Engine Design. This paper introduced the ideas of solution surfaces, constraint/thrust diagrams, quality measures and linear regression analysis for the engine design problem. It considered the application of the jet engine design software ACSYS, MISS, and ONX along with statistical analysis software, SAS. Modeling techniques and linear regression analysis were used to minimize iteration while searching a wide range of design variables. Improvements …

A Comparison Of Computational Fluid Dynamics Computer Programs For Hypersonic Propulsive Nozzle Flowfields, Kennedy B. Wilson Jr.

Theses and Dissertations

This study compared the results of two computer programs, a flux- difference-splitting (FDS) Godunov-based scheme and the SCPAMjet Hypersonic Nozzle (SCHNOZ) paraobolized Navier-Stoke's code using MacCormack's method, applied to a hypersonic nozzle flowfield. Two different nozzle geometries were investigated at three Mach numbers along a typical hypersonic flight trajectory. A direct compariosn between the SCHNOZ and FDS programs was made by numerically solving the steady Euler equations using a frozen flow assumption in the nozzle. The frozen flow SCHNOZ code is currently 6 to 10 times more efficient in terms of computational time than the FDS frozen flow code. The …

Increasing The Corrected Field Of View Of An Adaptive Optical Telescope, Dustin C. Johnston

Theses and Dissertations

Current adaptive optical telescope designs use a single deformable mirror (DM) to compensate for atmospheric distortion. The corrected field of view (FOV) of an adaptive optics system could be increased through the use of multiple DMs optically conjugated to corresponding planes which sample the turbulence region in altitude. Often, the atmospheric turbulence responsible for the degradation of telescope images is concentrated in several layers. Each DM would correct for the component of the total wavefront in the pupil contributed by one or more layers. If the atmosphere does not possess a layered structure, the best fit of the turbulence profile …

A Radiosity Approach To Realistic Image Synthesis, Richard L. Remington

Theses and Dissertations

The Air Force Institute of Technology (AFIT) has not had the capability to generate photorealistic images. This thesis is a research effort to implement such a system at AFIT, and to apply knowledge from the particle transport community to this problem. Investigation into various techniques for generating photorealistic images led to the conclusion that the radiosity method would serve as the foundation for development. This is because of the increased accuracy of the diffuse reflections with the radiosity method and the fact that the images produced with radiosity axe view-independent. Two distinct tools to generate photorealistic images axe described. The …

Efficient Derivation And Approximations Of Cepstral Coefficients For Speech Coding, Kimberly A. Limcangco

Theses and Dissertations

A new formulation is presented for the calculation of cepstral coefficients directly from measured sine wave amplitudes and frequencies of speech waveforms. Approximations to these cepstral coefficients are shown to be suitable for operation in a real-time speech coding environment. These results were encoded in the C programming language and then evaluated through experiments that were conducted on the McAulay-Quatieri Sinusoidal Transform Coder (STC).

X-Aaarf An X Windows Version Of The Afit Algorithm Animation Research Facility, Charles R. Wright Jr.

Theses and Dissertations

The AFIT Algorithm Animation Research Facility was developed by the Air Force Institute of Technology (AFIT) as a teaching aid for data structures and algorithm design of sequential processes. However, AAARF's unique design makes it particularly suitable for the animation of algorithms running on remote systems. In particular, an extensive set of parallel performance animations has been developed for the Intel iPSC/2 Hypercube for parallel program analysis and performance optimization. The AAARF system was originally developed using the Sun Microsystems' SunView(TM) windowing system. Recent advances in Graphical User Interface (GUI) technology combined with Sun's adoption of the X Window System …

Etann Hardware Implementation For Radar Emitter Identification, James B. Calvin Jr.

Theses and Dissertations

This study investigated classification of 30 radar emitters with 16 signal features using Intel's 80170NX chip, the Electronically Trainable Analog Neural Network (ETANN). Software tools were developed to characterize the ETANN sigmoidal transfer function for use in a custom simulator, known as Neural Graphics. Neural Graphics operates on a Silicon Graphics workstation. The Intel Neural Network Training System simulators were used in early experiments, but were found to be inefficient in training on data used in this research. Using a modified Neural Graphics simulator, single chip and multi-chip experiments were performed to provide benchmark results prior to performing chip-in-loop training. …

A Generic Template Extractor (Gentex) In C For Vlsi Design Verification, Kenneth J. Mcclellan Jr.

Theses and Dissertations

The problem of VLSI design verification through circuit extraction was analyzed. The problems of creating a simple template format, the permutability of pins, maintaining connectivity, and performance were focused on. A generic template extractor (GENTEX) was developed in the C programming language for use as a testbed to find solutions to these problems. Six different extraction algorithms were tested with GENTEX and compared based on performance. EDIF translation programs were used to interface with GENTEX on both the input and output sides. One translation program converted an EDIF representation of a schematic into the template format used by GENTEX. The …

Signal Approximation With A Wavelet Neural Network, Charles M. Westphal

Theses and Dissertations

This study investigated the use of Wavelet Neural Networks (WNN) for signal approximation. The particular wavelet function used in this analysis consisted of a summation of sigmoidal functions (a sigmoidal wavelet). The sigmoidal wavelet has the advantage of being easily implemented in hardware via specialized electronic devices like the Intel Electronically Trainable Analog Neural Network (ETANN) chip. The WNN representation allows the determination of the number of hidden-layer nodes required to achieve a desired level of approximation accuracy. Results show that a bandlimited signal can be accurately approximated with a WNN trained with irregularly sampled data. Signal approximation, Wavelet neural …

Perceptions About Strategies And Processes Necessary In Minnesota To Integrate Systems To Increase Services To Children And Families, Harold King Larson

Theses and Dissertations

This Minnesota study was intended to obtain, describe, and analyze legislator, state commissioner, and local service providing agency director perceptions of the change strategies and processes which might permit integrated delivery systems and services to increase and improve services to children and families. The specific research questions asked were (1) How do the policymakers and stakeholders perceive the issues which led to the 1990 legislative initiative in Minnesota? (2) Are there consensual perceptions among the policymakers regarding these issues? (3) What are the policymaker and stakeholder perceptions regarding the efficacy of certain (a) change strategies and (b) change processes? Are …

An Experimental Determination Of The Effects Of Blending Collocated And Non-Collocated Sensor Measurements To Control A Flexible Structure, Richard G. Cobb

Theses and Dissertations

An experimental investigation was performed controlling a cantilevered beam in bending using proportional feedback on a blend of collocated and non-collocated sensor measurements using a single actuator. Exact transfer functions between the control input and the measurements were developed and compared to the finite element method. By analyzing the open loop pole-zero locations as a function of the measurement blending, insight into the closed loop behavior is obtained. Minimum phase behavior can be maintained for a range of the blending ratio. Results using blended control were compared to both proportional collocated feedback and compensated collocated feedback using LQG methods. The …

Sectionalism And The Representation Debate, 1787-1792, John E. Grenier

Theses and Dissertations

From 1787 until 1792 the issue of the apportionment of representatives in the House of Representatives was the focus of spirited debate in American politics. The central issue at stake was the size and influence of each of the sections in future Congresses. The representation issue was first debated during the Constitutional Convention in 1787. After a temporary settlement of the representation guestion in the Convention, the First Congress re-opened the apportionment debate. The result was a constitutional amendment that would have significantly increased the size of the House of Representatives. After that amendment failed to pass the states, the …

A Morphophonology Of Komo: Non-Tonal Phenomena, John Paul Thomas

Theses and Dissertations

Komo, a sub-Bantu language spoken in northeastern Zaire, exhibits a number of interesting interactions between the morphology and phonology during the process of word derivation. A framework using parametric rule description, underrepresentation of morphemes, and lexical phonology is used in describing non-tonal phenomena of the language. Use of this framework results in optimalizing the description of lexical entries and simplifying the derivation of forms exhibiting complex phonological alternations. Complete paradigms of verbs in a number of tense-aspect-mood configurations are included, even though they may go beyond the requirements of the analysis. This brings to light a language that has not …

The Effects Of Caffeine On Search Rate In Working Memory, George C. Erickson

Theses and Dissertations

No abstract provided.

The New Politics Of Fear: The 1977 Dade County Gay Rights Referendum And The Regeneration Of The Radical Right, 1969-1980, Micheal J. Melgaard

Theses and Dissertations

No abstract provided.

Teacher Exposure To And Knowledge Of People With Virtual Impairment And The Effect On Attitudes Towards Mainstreaming, Robert Wall

Theses and Dissertations

No abstract provided.

Fantasy Proneness And Psychological Coping, Kenneth D. Huff

Theses and Dissertations

In this study, objective measures of self-esteem, satisfaction with life, trait anxiety, and schizotypal psychopathology were administered to 493 subjects representing the full range of fantasy proneness as determined by their scores on the Inventory of Childhood Memories and Imaginings (ICMI); in addition, subjects selected for high, medium, and low levels of fantasy proneness were administered measures of state anxiety and coping skills during a stressful laboratory condition. This was done in order to contribute to the construct validity of fantasy proneness and to provide empirical inquiry into the nature of fantasy proneness as a psychological coping strategy.

In replication …

Corporate Information Management And Business Process Improvement Under The Unit Cost Program: An Analysis Of A System For The Air Force Institute Of Technology, Kevin D. Kettell, Fredrick T. Ziegler Ii

Theses and Dissertations

DOD has been undergoing changes toward a competitive business-type environment as a result of the Packard Commission and -the Goldwater-Nichols Act. As a result of the Goldwater-Nichols Act, two programs directly affect the Air Force Institute of Technology (AFIT): Defense Management Report Decision 971, better known as the Defense Business Operations Fund (DBOF); and, the Corporate Information Management (CIM) initiative. DBOF requires that organizations provide unit cost per output figures as the basis for organizational funding. Unit cost resourcing changes the way federal managers manage and allocate resources, and promotes quality management and continuous improvement principles. Defense Information Management recognizes …

Excitation And De-Excitation Mechanisms Of Er-Doped Gaas And Algaas, David W. Elsaesser

Theses and Dissertations

Electrical and optical characterization have been performed on GaAs and Al_xGa_1-xAs samples doped with Er either by ion implantation or during Molecular Beam Epitaxial (MBE) growth. Deep Level Transient Spectroscopy (DLTS) and Temperature-Dependent Hall Effect (TDH) measurements indicated the presence of two hole traps in Er-doped GaAs, at 35 and 360 meV above the valence band maximum. The former (shallower) center was thought to be due to Er substituting for a Ga atom (Er_Ga) and giving rise to an isoelectronic impurity potential. The second center was attributed to an Er atom occupying an interstitial …

"Butchery And Plunder In God's Name": The Causes Of Oliver Cromwell's 1649-1650 Irish Campaign, Thomas M. Mulhern

Theses and Dissertations

This thesis proposes to examine the campaign of Oliver Cromwell against the Irish in the years 1649-1650, and its immediate and long-range causes. This will be done by examining the campaign itself and the history of the English and Irish from their first meeting to the final confrontation between the Irish and Cromwell.

The introduction looks at the events occurring, in England and Ireland, in 1649 and why Cromwell was called upon to mount a campaign against the Irish.

The first chapter explores the Ulster Rising of 1641 and the eight years of war that followed, culminating in the arrival …