Digital Commons Network^™

An Analysis Of The Influence Of Lesson Study On Preservice Secondary Mathematics Teachers' View Of Self-As Mathematics Expert, Julie Stafford

Theses and Dissertations

This research seeks to investigate the influence of lesson study on preservice secondary mathematics teachers' view of self as mathematics expert. The study acknowledges the commonly held belief that prospective mathematics teachers have that they know and understand secondary mathematics. The purpose in engaging the preservice teachers in lesson study is to dislodge this belief. In particular, this research report focuses on one preservice teacher and her experiences during lesson study. Using the data collected, the researcher reports on the baseline beliefs that the preservice teacher held toward her knowledge of secondary mathematics, her mathematical experiences during the actual lesson …

An Approach To Concept Development For Compliant Mechanisms Possessing High Coefficients Of Restitution, Brandon H. Woolley

Theses and Dissertations

The design of structures and mechanisms subject to impact loading has historically involved designing in such a way as to minimize damage induced by the impact. This has historically been accomplished by absorbing and dissipating the energy of the impact. However, in some applications it is desirable to harness the energy and return it to the impacting object to maximize the coefficient of restitution (COR), resulting in large rebound velocities. The use of traditional rigid-body mechanisms to achieve high-COR mechanisms is limited by issues of friction, durability, poor strain-energy distribution and others. Compliant mechanisms do not possess the same limitations …

Sandwich Theorem And Calculation Of The Theta Function For Several Graphs, Marcia Ling Riddle

Theses and Dissertations

This paper includes some basic ideas about the computation of a function theta(G), the theta number of a graph G, which is known as the Lovasz number of G. theta(G^c) lies between two hard-to-compute graph numbers omega(G), the size of the largest lique in a graph G, and chi(G), the minimum number of colors need to properly color the vertices of G. Lovasz and Grotschel called this the "Sandwich Theorem". Donald E. Knuth gives four additional definitions of theta, theta_1, theta_2, theta_3, theta_4 and proves that they are all equal.

First I am going to describe the proof of the …

Channel Probing For An Indoor Wireless Communications Channel, Brandon Hunter

Theses and Dissertations

The statistics of the amplitude, time and angle of arrival of multipaths in an indoor environment are all necessary components of multipath models used to simulate the performance of spatial diversity in receive antenna configurations. The model presented by Saleh and Valenzuela, was added to by Spencer et. al., and included all three of these parameters for a 7 GHz channel. A system was built to measure these multipath parameters at 2.4 GHz for multiple locations in an indoor environment. Another system was built to measure the angle of transmission for a 6 GHz channel. The addition of this parameter …

Physical Activity And Changes In Abdominal Fat Over 18 Months: A Prospective Study Of Middle-Aged Women, Lance Eric Davidson

Theses and Dissertations

Objective: To investigate the extent to which changes in physical activity predict changes in abdominal fat in women over an 18-month period, while statistically controlling the effects of possible confounders, such as age, total body fat percent, and energy intake. Design: A prospective cohort design over 18 months. There was no intervention or treatment. Changes in objectively-measured physical activity were used to predict changes in abdominal fat over the study period. Subjects: 110 healthy, middle-aged women (mean: 41.3±3.3 yrs), primarily Caucasian, educated, and married. Measurements: An objective measure of physical activity (ACT) using CSA accelerometers, worn continuously for 7 consecutive …

On-Chip Actuation Of Compliant Bistable Micro-Mechanisms, Michael S. Baker

Theses and Dissertations

Two compliant bistable micro-mechanisms have been developed which can be switched in either direction using on-chip thermal actuation. The energy storage and bistable behavior of the mechanisms are achieved through the elastic deflection of compliant segments. The pseudo-rigid-body model was used for the compliant mechanism design, and for analysis of the large-deflection flexible segments. To achieve on-chip actuation, the mechanism designs were optimized to reduce their required rotation, allow them to be switched using linear-motion thermal actuators. The modeling theory and analysis are presented for several design iterations. Each iteration was successfully fabricated and tested using either the MUMPs or …

Thermal Microactuators For Microelectromechanical Systems (Mems), Rebecca Cragun

Theses and Dissertations

Microactuators are needed to convert energy into mechanical work at the microscale. Thermal microactuators can be used to produce this needed mechanical work. The purpose of this research was to design, fabricate, and test thermal microactuators for use at the microscale in microelectromechanical systems (MEMS). The microactuators developed were tested to determine the magnitude of their deflection and estimate their force. Five groups of thermal microactuators were designed and tested. All of the groups used the geometrically constrained expansion of various segments to produce their deflection. The first group, Thermal Expansion Devices (TEDs), produced a rotational displacement and had deflections …

An Investigation Of Compliant Over-Running Ratchet And Pawl Clutches, Gregory Mark Roach

Theses and Dissertations

This thesis proposes that compliant mechanism theory can be used to design over-running ratchet and pawl clutches with reduced part count, lower assembly and manufacturing time while maintaining functionality. An extension of the theory to the micro regime is also briefly addressed. The results of the research show that the ratchet and pawl type of over-running clutch is a good choice for the use of compliance, and the clutch pawls should be loaded in compression to get the largest amount of output torque. It was found that com-pliant mechanism theory can be used to design ratchet and pawl clutches with …

Designing, Debugging, And Deploying Configurable Computing Machine-Based Applications Using Reconfigurable Computing Application Frameworks, Anthony Lynn Slade

Theses and Dissertations

Configurable computing machines (CCMs) offer high-performance application acceleration with custom hardware. They are also dynamically reconfigurable and give significant internal visibility. Such features are useful throughout the design, debug, and deploy stages of CCM-based application development. However traditional, monolithic design tools do not offer adequate support for all of these development stages. This thesis describes a specification for a reconfigurable computing application framework (RCAF) which is more suitable for CCM application development. It also describes an implementation of such an RCAF. This RCAF improves the efficiency of application design and debugging. It also establishes an application architecture framework which helps …

Ontology-Based Extraction Of Rdf Data From The World Wide Web, Timothy Adam Chartrand

Theses and Dissertations

The simplicity and proliferation of the World Wide Web (WWW) has taken the availability of information to an unprecedented level. The next generation of the Web, the Semantic Web, seeks to make information more usable by machines by introducing a more rigorous structure based on ontologies. One hinderance to the Semantic Web is the lack of existing semantically marked-up data. Until there is a critical mass of Semantic Web data, few people will develop and use Semantic Web applications. This project helps promote the Semantic Web by providing content. We apply existing information-extraction techniques, in particular, the BYU ontologybased data-extraction …

An Analysis Of Microbial Contamination In Military Aviation Fuel Systems, Harold W. Graef

Theses and Dissertations

Military aviation fuel systems can be an ideal environment for microorganisms. Microbial growth in hydrocarbon fuel systems arises because of the impracticality of keeping fuel tanks sterile and the inevitable presence of water from condensation. Microbial contaminants in aviation fuel systems are a concern because of their potential to degrade the fuel, accelerate tank corrosion, and threaten flight safety. This research addresses the concern of using more environmentally friendly Fuel System Icing Inhibitors (FSII), which are also biocidal. Are significant levels of microorganisms growing in military aviation fuel systems, and if so, are there any common variables? Forty aviation fuel …

Inquisitive Pattern Recognition, Amy L. Magnus

Theses and Dissertations

The Department of Defense and the Department of the Air Force have funded automatic target recognition for several decades with varied success. The foundation of automatic target recognition is based upon pattern recognition. In this work, we present new pattern recognition concepts specifically in the area of classification and propose new techniques that will allow one to determine when a classifier is being arrogant. Clearly arrogance in classification is an undesirable attribute. A human is being arrogant when their expressed conviction in a decision overstates their actual experience in making similar decisions. Likewise given an input feature vector, we say …

Experimental And Computational Failure Analysis Of Graphite/Bismaleimide Laminated Composite And Carbon Foam In Sandwich Construction, Troy C. Welker

Theses and Dissertations

Sandwich beams consisting of a carbon foam core and graphite/bismaleimide face sheets were constructed and tested. Nine specimens were fabricated using three distinct cross-ply symmetric face sheet layups with a constant core thickness. Four-point bend testing controlled by a constant rate of midspan vertical displacement was used to load the specimens to failure. Displacements and strains from the experiment were compared to analytical sandwich beam theory and displacements and failure loads were compared to a layerwise finite element solution. A phenomenological failure criterion was developed that compares favorably with experimental failure data. The finite element solution gives failure within an …

The Air Warrior's Value Of National Security Space, John D. Loftis

Theses and Dissertations

The 2001 Report of the Commission to Assess United States National Security Space Management and Organization recommended that U.S. efforts in national security space be elevated to the highest national security priority. With more focused high-level attention on national security space decisions a measure that captures and quantities the value of space capabilities to combat operations professionals is desired. This thesis models what the air warriors desire from space assets in combat. A Value-Focused Thinking (VFT) approach was used to elicit values from air combat experts with operational experience. An initial Gold Standard value model was constructed and validated by …

Phasing A Dual Optical Path System Using An Optical Fiber As A Phase Conjugate Mirror, Shawn M. Willis

Theses and Dissertations

Phase conjugation properties of stimulated Brillouin scattering (SBS) in a short multimode fiber have been investigated with an eye towards its application for a multi-channel double pass master oscillator power amplifier (MOPA) system. In particular, properties of the SBS beam to compensate for the axial and transverse phase distortion between individual channels in a multi-channel amplifier system were studied. Two optical paths were created by covering half of the laser beam with a microscope slide, and also by spatially splitting the wavefronts with a 4 prism set-up. The Stokes beams that traversed the same optical paths as the pump beams …

The Effects Of Perceived Overqualification On Job Satisfaction, Organizational Commitment, And Turnover: A Study Of Afit Graduates, Thomas E. Hoskins

Theses and Dissertations

The U.S. Air Force provides multiple program to increase the educational skills of its workforce. This study focuses on the Air Force Institute of Technology (AFIT) graduate level, in-residence degree program. The Air Force is making a significant investment in the education of its members. Studies on perceived overqualification, overeducation, and match quality suggest that utilization plays a role in an individual's job satisfaction and organizational commitment. Job satisfaction and organizational commitment levels can be used as predictors of turnover. This research studies the levels of perceived overqualification in AFIT graduates and how it effects their job satisfaction, organizational commitment, …

An Analysis Of Engagement Of Those Who Telecommute Vs Those Who Do Not, Daniel J. Boeh

Theses and Dissertations

Telecommuting is a program used by many of the successful companies in the private sector, both as a cost savings measure and as a way to recruit and retain quality personnel. Telecommuting has also been used by many companies to adhere to stricter environmental mandates. The public sector, however, has been slow to implement telecommuting programs. Buckingham and Coffman of the Gallup Organization have done extensive research into what they call "engagement," and as to what comprises an engaged employee. They also developed a twelve question survey (referred to as the Q12) to determine if an employee is engaged or …

Reverse Geographic Location Of A Computer Node, Clinton G. Carr Iii

Theses and Dissertations

The determination of methods by which a user is able to locate his computer when that user does not know his current location, termed "homestation", will provide the Air Force an advantage over its adversaries. The methods are a combination of different mathematical techniques that enable the user to manipulate data to minimize the effects of delay caused by various factors on the network. The techniques use the smallest round trip time obtained from the ping utility. This time is then converted into miles and plotted on a map of the United States. The methods used to solve this problem …

Performance Evaluation And Analysis Of Effective Range And Data Throughput For Unmodified Bluetooth Communication Devices, Timothy F. Kneeland

Theses and Dissertations

The DoD and the Air Force continually seek to incorporate new technology in an effort to improve communication, work effectiveness, and efficiency. Office devices utilizing Bluetooth technology simplify device configuration and communication. They provide a means to communicate wirelessly over short distances thereby eliminating the need for different vendor specific cables and interfaces. One of the key concerns involved in incorporating new communication technology is security; the fundamental security concern of wireless communication is interception. Studies focusing on IEEE 802.11b have shown vulnerability zones around many DoD installations that reflect the ranges at which wireless communications using the 802.11b standard …

Implementing An Information Retrieval And Visualization Framework For Heterogeneous Data Types, Andrew J. Kowalchuk

Theses and Dissertations

In today's information focused world, there is no lack of entities focused on information gathering. However, there is still a widespread epidemic of information starvation in the Department of Defense (DoD). This starvation is attributed to the lack of interoperability between information gatherers and information consumers. To alleviate this problem, the DoD has put forth a vision of a Joint Battlespace Infosphere (JBI). This research proposes a framework for sharing and finding resources in a JBI. The framework uses an extensible metadata specification, agent technology, and the Control of Agent Based Systems (CoABS). It provides several tools for publication and …

Groundwater Flow Through A Constructed Treatment Wetland, Jack A. Blalock

Theses and Dissertations

This study is an analysis of the flow of water through a constructed treatment wetland at Wright-Patterson AFB, OH. The purpose of the treatment wetland is to biodegrade perchioroethylene, which is present in the groundwater as a contaminant. Contaminated water enters the bottom of the wetland and flows upward, exiting the wetland from a weir at one end. The wetland is designed for water to move vertically through the soil layers composing the wetland. The main purpose of this study is to characterize the water flow through the different layers of soil in the wetland. In this study, hydraulic parameters …

Modeling Catalytic Destruction Of Subsurface Contaminants In Recirculating Wells, Kerry J. Cadena

Theses and Dissertations

Groundwater and soil contamination is a significant problem throughout the nation, with approximately 300,000 to 400,000 sites affected (National Research Council, 1994). Examples of groundwater contaminants of special interest to DoD and AF installations include fuel hydrocarbons, chlorinated hydrocarbons, and nitroaromatic compounds. Traditional remediation technologies, which include pump-and-treat, permeable reactive barriers, and natural attenuation, have numerous drawbacks associated with them. These drawbacks have prompted researchers to look for innovative contamination clean-up methods. The technology investigated in this thesis, reticulating horizontal flow treatment wells (HFTWs) with in-well palladium (Pd) catalyst reactors, offers the potential for destruction of groundwater contaminants commonly found …

Strategies Leaders Should Use To Respond To Hostile Questions Regarding Organizational Changes: An Empirical Investigation, Michael S. Gore

Theses and Dissertations

The purpose of this research was to develop a tool, using Speech Act Theory, which will help leaders better handle hostile questions they face during organizational change. Specifically, speech act theory, which outlines five question-response strategies, was used to test the effectiveness of question responses to hostile questions encountered during organizational change.

Understanding The Dynamic System Of Terrorist - Government Interaction, John A. Hanrahan

Theses and Dissertations

The nature of action and reaction that forms the basis for terrorist - government interactions creates a dynamic system. Understanding how this dynamic system behaves in response to key government activities can help the government better control the overall behavior of the system. The system dynamics methodology is one tool that can help the government solve specific behavioral problems within the overall system. This research shows the ability of system dynamics to help develop government policy towards terrorism that can directly affect a terrorist's behavior. It supports a government policy of offensive action instead of defensive reaction. It also identifies …

Optimizing An In Situ Bioremediation Technology To Manage Perchlorate-Contaminated Groundwater, Mark R. Knarr

Theses and Dissertations

Combining horizontal flow treatment wells (HFTWs) with in situ biodegradation is an innovative approach with the potential to remediate perchlorate-contaminated groundwater. A technology model was recently developed that combines the groundwater flow induced by HFTWs with in situ biodegration processes that result from using the HFTWs to mix electron donor into perchlorate-contaminated groundwater. A field demonstration of this approach is planned to begin this year. In order to apply the technology in the field, project managers need to understand how contaminated site conditions and technology design parameters impact technology performance. One way to gain this understanding is to use the …

Analysis Of Anion Distributions In The Developing Strata Of A Constructed Wetland Used For Chlorinated Ethene Remediation, Joshua D. Kovacic

Theses and Dissertations

Perchloroethene (PCE), Trichloroethene (TCE) and their degradation products are among the most common organic groundwater contaminants in the United States. Constructed wetlands utilizing upward flow harbor reduction-oxidation conditions that have demonstrated the potential to promote both partial and total mineralization of PCE and TCE through the process of natural attenuation. Organic acid and inorganic anion concentrations are indicative of reduction-oxidation processes that drive chlorinated ethene degradation. These analytes were investigated to assess their development within three vertically stratified regions of a constructed wetland cell at Wright-Patterson Air Force Base fed by groundwater contaminated with PCE and TCE. Data collected during …

Palladium-Catalyzed Destruction Of Nitro Aromatic-Contaminated Groundwater, Dennis Landon Phillips

Theses and Dissertations

Of the over 17,000 DoD sites that potentially require remediation, sites containing soil and groundwater contaminated by energetic compounds are prevalent (Larson et al., 2001). Production of energetics such as 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5 - trinitro- 1,3,5 -triazine (RDX), and octahydro-1,3,5,7-tetranitro- 1,3,5,7-tetrasocine (HMX) for use in munitions has created a DoD-wide problem due to improper disposal techniques (Price et al., 2001), Nitro aromatic compounds (NACs) similar to those used in explosives can also be found in insecticides, herbicides, pharmaceuticals, dyes, plastics, and many other commonly used products. The natural breakdown of these contaminants creates byproducts such as amines, which are known …

Theoretical Analysis Of Information Watermarking In Wavelet-Based Video Compression, Brendan K. Casey

Theses and Dissertations

Embedding audio bits into images for transmission of video data alleviates the synchronization problem common in video transmission techniques. We continue work combining audio or other information bits and images into one file using digital watermarking techniques to correct the synchronization problem. The system compresses the file by using wavelet image coefficients and implementing bit plane coding. Our research encompasses incorporating five free variables into the watermark/compression technique. These variables are watermark robustness, number of coding iterations, number of image coefficients, number of watermarked information bits, and number of watermarked error correcting bits. By altering these variables, four measurements of …

Fast Compression Of Imagery With High Frequency Content, D. Scott Anderson

Theses and Dissertations

Image compression is an active area due to the many applications involving electronic media. Much research has been focused on image quality versus bit rate and/or algorithm speed. Here, we seek an effective image coder with a weighted constraint on speed. However, the compression must not taint the quality of impulsive features on the image. Moreover, the camera is operated in a mode that creates a dominant fixed pattern noise across the image array, degrading visual quality and disrupting compression performance. We propose a method that efficiently compresses such an image. We begin by characterizing and removing the fixed pattern …

Deception Detection In A Computer-Mediated Environment: Gender, Trust, And Training Issues, Monica A. Dziubinski

Theses and Dissertations

The Department of Defense is increasingly relying on computer-mediated communications to conduct business. This reliance introduces an amplified vulnerability to strategic information manipulation, or deception. This research draws on communication and deception literature to develop a conceptual model proposing relationships between deception detection abilities in a computer-mediated environment, gender, trust, and training. An experiment was conducted with 119 communications personnel to test the proposed hypotheses. No relationship between gender or trust and deception detection accuracy was found. Partial support was found showing that training improves deception detection accuracy. The most significant finding was that individual’s deception detection abilities deteriorate in …