Engineering Commons^™

The Effect Of Active And Passive Control On Air Traffic Controller Dynamic Memory, Esa M. Rantanen

Master's Theses - Daytona Beach

The purpose of this study was to investigate the effect of automated and passive control on air traffic controller dynamic memory. The study consisted of two experiments, each involving a realistic ATC scenario for radar approach control with a mix of arriving and departing traffic. In Experiment I, the subjects performed manual control of the traffic while, in Experiment II, the scenario was highly automated and the subjects were tasked with only monitoring the situation. The dynamic memory performance was measured by interrupting the scenario and having the subjects recall the traffic situation at the moment of simulation interruption. The …

Comparison Of Air Traffic Control Candidate Ability With Simulator-Based Training Measures, Lawrence A. Tomaskovic

Master's Theses - Daytona Beach

The purpose of this study was to determine if the utilization of an experimental computer-based selection test battery would aid in the prediction of a candidates performance when using an air traffic control computer-based simulation program. Each candidate completed the selection test battery, and then received air traffic control instruction using the air traffic control simulation program incorporated in the TRACON/Pro™ simulator system. The selection test battery results were correlated with the subsequent simulator scoring results.

Superplastic Forming System Design, Keith Bain

Honors Capstone Projects and Theses

No abstract provided.

Application Of Fuzzy Logic For Performance Enhancement Of Drives, Gilberto Costa Sousa

Doctoral Dissertations

Fuzzy logic shows enormous potential for advancing power electronics technology. Its application to DC and AC drives control is discussed here.

Initially, a phase-controlled bridge converter DC drive was considered. Analysis of converter performance at continuous and discontinuous conduction modes was first conducted. Fuzzy control was used to linearize the transfer characteristics of the converter in discontinuous conduction mode. It was then extended to current and speed loops, replacing the conventional proportional-integral controllers. The control algorithms were developed in detail, and verified by PC-SIMNON (developed by Lund Institute of Technology Sweden) digital simulation. Significant performance improvement was achieved over conventional …

Effect Of Joystick Versus Control Yoke Use On Personal Computer (Pc) Flight Training: A Comparative Analysis, Gregory Alan Fontaine

Master's Theses - Daytona Beach

The purpose of this study was to provide a comparative performance analysis of a generic control yoke device and a generic joystick device. The comparison provided data needed for further evaluation of personal computer (PC) aircrew training device (ATD) potential. Both devices were used in support of the same PC flight simulation software program, and were evaluated using the experimental research method. Objective and subjective data were obtained during controlled testing, and subsequently analyzed using basic summation and t-test methods. The results tested the research hypothesis that there is no significant difference in personal computer ATD operator performance using a …

The Use Of Videotape During Post-Flight Debriefing Of Simulator Flights To Improve Student Learning And Reduce Instructional Time, Stanley Paul Rowe

Master's Theses - Daytona Beach

The purpose of this study was to determine if videotaping students during simulator flights and using the results as a teaching tool would improve student learning and require less instructional time. Thirty subjects were randomly selected from students enrolled in an instrument rating flight course at Embry-Riddle Aeronautical University. A Frasca 141 simulator and a Panasonic video camera were used as the data gathering instruments. The treatment group reviewed the instructional lessons on videotape during their post-flight debriefing. At the end of the experiment, both groups received a posttest. The results of the posttest and the amount of instructional hours …

The Perception Of Travel Agents As To Passenger Acceptance Of The High Speed Civil Transport In Commercial Airline Service: A Study Of Tomorrow's Transpacific Air Travel, James H. Starnes Iii

Master's Theses - Daytona Beach

Through a cooperative effort between NASA, Boeing Commercial Airplane Group, Douglas Aircraft Company, GE Aircraft Engines, and Pratt & Whitney, technology for a new-generation supersonic transport aircraft is being developed. To determine if air travelers will choose this aircraft, the High Speed Civil Transport (HSCT), as their mode of air transportation on transpacific routes, a self-developed questionnaire was sent to randomly selected travel agents in the Los Angeles, California area. The questionnaire examined criteria that passengers use to select transpacific flights, including fare, schedule, flight time length, and comfort. Results indicated that all passengers will be attracted to supersonic air …

A Feasibility Study Of A Private Entity Competing With Fbos For Airline Ground Handling Contracts, Carlos A. Vergas

Master's Theses - Daytona Beach

This thesis investigates whether a private entity can compete with fixed base operators (FBOs) for airline ground handling contracts. Separating the research method into five phases, the author first conducts a need analysis. Then, the author dissects the structure of existing ground handling contracts. Thirdly, the average service charges presently in place are tabulated. Fourthly, a financial analysis is performed including the calculation of the break-even point at a profit. Finally, a model of ground handling operation is simulated using an existing air carrier’s ground handling contract.

Effect Of A Range Ring And Of Intruder Vertical Rate On Pilot Perception Of Separation On A Cockpit Display Of Traffic Information, Paul V. Wassell

Master's Theses - Daytona Beach

This study was conducted to determine the effect of a range ring and intruder vertical rate on pilots’ perception of aircraft separation as viewed on a cockpit display of traffic information. A group of 30 pilots from Embry-Riddle Aeronautical University participated as subjects. SuperCard® Version 1.6 software and a Macintosh IIsi® personal computer were employed to generate the simulation of a cockpit display of traffic information. Each pilot monitored 80 unique scenarios in which they determined, as early as possible, what the vertical miss distance would be when a single intruder passed ownship. The pilots’ decision time and perceived vertical …

Nitric Oxide Production: A Mechanism For Inhibition Of Chlamydia Trachomatis Replication, Bojun Chen

Electronic Theses and Dissertations

Chlamydia trachomatis (CT) replicates in macrophages, but is inhibited by IFN-$\gamma$ or LPS. IFN-$\gamma$ and/or LPS induced nitrite production in mouse peritoneal macrophages, macrophage cell lines (RAW264.7 and J774A.1) and McCoy cells. Kinetic studies indicated that peak production occurred 48 hours post-treatment. CT infection itself was insufficient to induce nitrite production, but resulted in enhancement of nitrite production in IFN-$\gamma$-treated cells. Treatment with IFN-$\gamma$ or LPS resulted in significant inhibition of CT replication in these cells. Strong correlation between nitrite production and inhibition of CT replication was observed in RAW264.7 and J774A.1 cells (correlation coefficients: $-$0.93 and $-$0.94, p $<$ 0.001). N$\sp{\rm g}$- monomethyl-L-arginine (L-NMMA) specifically inhibited nitrite production and partially reversed inhibition of CT replication in macrophage cell lines. NOS mRNA was measured in RAW264.7 cells by Northern blot and Dot blot hybridization. Strong correlation between NOS mRNA expression and inhibition of CT replication (correlation coefficient: $-$0.97, p $<$ 0.05) was observed. Anti-TNF-$\alpha$ antibody completely neutralized the biological activity of TNF-$\alpha$ secreted by LPS-treated RAW264.7 cells, yet the antibody neither reduced nitrite production nor restored CT replication. Combination of the antibody and L-NMMA significantly enhanced restoration of CT replication. In peritoneal macrophages, inhibition of CT replication induced by IFN-$\gamma$ was partially restored by L-NMMA or anti-TNF-$\alpha$ antibody. In McCoy cells, inhibition of CT replication induced by IFN-$\gamma$ and LPS was not significantly restored by L-NMMA. Great restoration of CT replication by 1 mM L-NMMA was observed in LPS-treated J774A.1 cells (31%), but not in IFN-$\gamma$-treated cells (5%). Our data indicate that (1) NO production is one of the mechanisms for inhibition of CT replication in IFN-$\gamma$-activated peritoneal macrophages and RAW264.7 cells; (2) NO plays a significant role in CT inhibition in LPS-treated macrophage cell lines, but not peritoneal macrophages; (3) TNF-$\alpha$ may be associated with inhibition, but the mechanism(s) may not involve NO production; (4) NO production may not be the mechanism for CT inhibition in McCoy cells treated with IFN-$\gamma$ and LPS.

Evaluation And Implementation Of Asynchronous Adders, Poornima Y. Shankarreddy

Masters Theses

The need for high speed addition is forcing digital system designers to trade off space. If speed is used as a criterion to judge adders, then the Ripple Carry Adder (RCA) and the Carry Look Ahead Adders (CLAAD) will rank last and first respectively. On the other hand, if space is used, then the order of these two is reversed. The rest of the adders rank between these two. This paper evaluates RCA, CLAAD, and some of the other well documented adders. Both space and speed are used to judge the merits of each of these, and whether or not …

Development Of A Systematic Approach To The Implementation Of A Computer Integrated Manufacturing (Cim) For Small To Medium Sized Companies, G. Steven Trimmer

Masters Theses

CIM technology is rapidly becoming an essential part of businesses of all types and sizes. The impact on the culture of the enterprise is possibly of even greater complexity. Most existing implementations have been done by large businesses large teams of specialized talent.

The unique scope of this work is to simplify the implementation of CIM for small companies. The basic research derived from the WMU/IBM CIM Management Center, a fully functioning CIM facility that provides hands on experience to students and regional businesses.

The cultural references concerning CIM are derived from reading and personal experiences with industry while setting …

A Physics-Based Heterojunction Bipolar Transistor Model For Integrated Circuit Simulation, James A. Fellows

Theses and Dissertations

The purpose of this research effort was to derive a physics-based dc model for a Heterojunction Bipolar Transistor HBT. The dc model was then linearized to arrive at a small-signal model that accurately predicts the devices electrical behavior at microwave frequencies. This new model offers features not found in previous analytical or physics-based HBT models such as consideration of a cylindrical emitter-base geometry and is direct implementation into SPICE Simulation Program with Integrated Circuit Emphasis. The device model parameters were determined from a knowledge of the device material, geometry, and fabrication process. The model was then developed by using semiconductor …

Developing A Graphical User Interface To Support A Real-Time Digital Signal Processing System, Jeffrey C. Miller

Theses and Dissertations

A graphical software user interface for a VMEbus-based real-time digital signal processing system was designed. Use, requirements were defined and the Rumbaugh object-oriented analysis and design technique was applied to analyze the requirements and produce an object-oriented design. The software design includes a graphical, mouse- and keyboard driven user interface, specialized hardware driver modules, and operating system interfaces. An implementation plan was also developed to map the design into the C programming language using existing system code, automatically generated code, and newly written code. Based on the implementation plan, a limited software system prototype w successfully developed and demonstrated. The …

An Evaluation Of The Software Engineering Institute's Capability Maturity Model As A Framework For Software Process Improvement At Three Air Logistics Centers, Brian G. Hermann, Raymond J. Lewis Jr.

Theses and Dissertations

This research sought to determine whether a relationship exists between the maturity level of the software process, as determined by the Software Engineering Institutes Capability Maturity Model SEI CMM, and the actual success of particular software projects at three US Air Force Air Logistics Centers. Project success is defined in terms of cost, schedule, and quality criteria. In addition, each organizations acceptance of the SEI assessment as well as its effectiveness in setting up follow-on process improvement programs were evaluated. Finally, the process improvement programs were reviewed individually inasmuch as these programs are the mechanisms for achieving improved quality, lower …

An Assessment Of The Appropriateness To The Royal Australian Air Force Of A Masters Level Professional Program In Information Systems, Ralph G. L. Kettle, Joseph R. Taylor

Theses and Dissertations

This study assessed the appropriateness, to the Royal Australian Air Force RAAF, of a graduate professional program in Information Systems (IS) based on the Association for Computing Machinery’s ACM curriculum model. The ACM curriculum model is an archetype of graduate education in IS. Programs based on this model produce graduates with knowledge, skills, and abilities (KSAs) that are required by IS practitioners. The usefulness of twenty KSAs that underlie the ACM curriculum model were evaluated by 33 incumbents of RAAF information Systems Agencies and Directorate of Communications and Information Systems - Air Force. Although uncertain about the educational background suited …

Demonstration Of Improved Software Support Labor Estimation For Air Force Operational Flight Programs Through Functional Orientation, Ronald R. Warner Jr., Darrel L. Wright

Theses and Dissertations

This study demonstrated two approaches to improve current software support effort estimation models for aircraft software. Both approaches involved a functional orientation not used by existing models. The first approach demonstrated how to orient a model to reflect the block change cycle modification process and how to represent support effort changes over time in order to improve effort estimation accuracy. Current software models do not reflect the support environment or the temporal characteristics of aircraft software support. The second approach demonstrated how to calibrate a model by properly selecting source data in order to increase accuracy. Support calibration is not …

System Design Analysis Of A Lightweight Laser Satellite Terminal, Brian C. Page

Theses and Dissertations

This study investigated the technological feasibility of a man- portable satellite laser communications system. Areas of interest were an end- to-end system analysis on the communications link evaluation of atmospheric effects and evaluation of semi-conductor lasers as the laser source. A literature search revealed that satellite laser communication research is primarily directed at inter-satellite links. There have been some proposed systems for space-to-ground laser communications systems, but they all utilize large fixed ground stations. The focus of this research effort is directed at a small man-portable ground station capitalizing on recent advances in semiconductor laser devices. Baseline satellite communication systems …

Measuring User Satisfaction Of The Electronic Mail System At Air Force Materiel Command Headquarters As An Indicator Of The System's Effectiveness, Randall R. Bradford

Theses and Dissertations

The purpose of this study was to evaluate the effectiveness of the electronic mail system at the Air Force Materiel Command Headquarters. User satisfaction was measured as an indicator of the systems effectiveness. In order to provide an objective measurement of system effectiveness, the following research questions were addressed: (1) What is system effectiveness in relation to this particular electronic mail system, and how should it be measured? (2) What measurement instruments can be adapted, modified, or created to measure effectiveness as it is defined for problem? (3) If a measurement instrument is administered what do the results of the …

Guidelines For Ensuring Software Supportability In Systems Developed Under The Integrated Weapon System Management Concept, Forrest F. Butts Iii, Anthony C. Johndro

Theses and Dissertations

This thesis studied the software maintenance planning and practices of the pilot Integrated Weapon System Management IWSM programs. Before IWSM, a System Program Office SPO acquired an Air Force weapon system then passed it to an Air Logistics Center ALC for follow-on support. The ALC was forced to maintain the software despite its questionable maintainability. The SPO de- emphasized maintainability because maintenance was an ALC responsibility and building maintainable software increased development costs and lengthened schedules. The IWSM philosophy closes the gap between development and maintenance. A System Program Director SPD, who oversees both system development and maintenance, has an …

Primary Coolant Flow Characteristics As It Exits The Palisades Reactor, Gregory Alan Baustian

Masters Theses

During fuel cycles 9 and 10 at the Palisades Nuclear Power Plant, new phenomena have been observed using the resistance temperature devices installed in the reactor coolant piping. Oscillations in the temperature readings have been observed leading to the assumptions that there is temperature stratification of the coolant in the reactor hot-legs and that the coolant rotates as it leaves the reactor. In addition, oscillations in the bulk coolant flow within the two hot legs have been postulated. This report outlines work performed using computational fluid dynamics modelling which predict the observed and assumed flow characteristics of the Palisades reactor …

Development Of Stereoscopic Particle Tracking Velocimetry For Turbulent Flow Field Diagnostics, Veera P. Rajendran

Electronic Theses and Dissertations

Stereoscopic particle tracking velocimetry (SPTV) was used to analyze a turbulent submerged jet of Reynolds number (based on the diameter of the nozzle) 8000. SPTV involves tracking the motion of tracer particles over time in a flow in three dimensions. The first part of this work consisted of developing a stereoscopic particle tracking technique using two high-speed video cameras. This included calibration of the cameras with "known" points, and developing an algorithm to automatically match and track particles. The second part was to apply the same to a submerged water jet in order to measure velocities. The velocities were subsequently …

An Empirical Investigation Of Quality And Productivity Management Practices In Manufacturing Firms, Kiran Vuppalapati

Masters Theses

A growing number of firms are implementing the concept of Just In Time (JlT) manufacturing and Total Quality Management (TQM). This research examines the impact of these management philosophies in manufacturing firms.

This research identifies a set of critical organizational variables necessary for a successful . implementation and the organizational problems faced during their implementation. The major object is to test the performance of firms implementing both JlT and TQM against firms implementing none of these philosophies. Results show that JIT-TQM firms are more customer focused and have better employee relations than traditional firms. This study also compares the performance …

Modeling Of A Large Undamped Space Structure Using Time Domain Techniques, Anthony R. Nash

Theses and Dissertations

The first phase of this project was the selection of accurate time domain state space modeling techniques by comparing the models generated by various methods, against a known system. The techniques selected were the Eigensystem Realization Algorithm and the Backward Least Squares method. These modeling techniques were applied to the vibration data from the PACOSS dynamic test article. The resulting model transfer function was then compared to the frequency response function of the actual system, and was found to be an accurate match for the system poles, but not for the system zeros. Large Space structures, Dynamic Control, System Mode …

An Experimental Study Into The Role Of Routing Flexibility In The Justification Of Advanced Manufacturing Systems, Sanjay Pathak

Masters Theses

Increased competition in manufacturing has focused attention on advanced technologies. These costly technologies lead to difficulty in purchase justification using traditional methods. New methods quantify attributes relating to the flexibility of advanced systems. One such attribute is routing flexibility.

This thesis presents results of experiments into evaluation of routing flexibility. The performance of conventional dedicated machinery when compared with that of machines having routing flexibility indicates an advantage of flexible machinery. The thesis indicates a procedure for evaluation of different flexibilities and their comparison with conventional machinery in reality.

An empirical formula is developed that helps in quantifying routing flexibility …

Development And Implementation Of A Scramjet Cycle Analysis Code With A Finite-Rate-Chemistry Combustion Model For Use On A Personal Computer, Clarence F. Chenault

Theses and Dissertations

This study compared the performance of an equilibrium combustion model to a finite-rate-chemistry combustion model for a fixed geometry Scramjet flying at the flight conditions of Mach 12, 15, and 18 with a constant dynamic pressure of 50,000 Pa. An integrated PC-based code, developed specifically for this study, models the combustor as an equilibrium combustion process or as finite-rate-chemistry combustion process. This integrated program is based on two existing programs, Ramjet Performance Analysis (RJPA) and 3 STREAM. The effects of mixing schedule, combustor length, and combustor exit area were investigated. The results of this study indicate that inefficient mixing is …

Binaural Room Simulation, Brian A. Smith

Theses and Dissertations

Research in binaural and spatial hearing is of particular interest to the Air Force. Applications in cockpit communication, target recognition, and aircraft navigation are being explored. This thesis examines human auditory localization cues and develops a mathematical model for the transfer function of a sound signal traveling from an isotropic point source through a rectangular room to both ears of a listener. Using this model as a guide, non-head coupled binaural sound signals are generated in a binaural room simulation. Reflection and attenuation cues included in the computer generated signals are varied in order to determine which cues enhance the …

Control Of A Large Space Structure Using Multiple Model Adaptive Estimation And Control Techniques, Gregory J. Schiller

Theses and Dissertations

The purpose of this thesis is to apply moving-bank multiple model adaptive estimation and control MMAEMMAC algorithms to an actual space structure SPICE being examined at Phillips Laboratory at Kirtland AFB, NM. The structure consists of a large platform and a smaller platform connected by three legs in a tripod fashion. Kalman filtering and LQG control techniques are utilized as the primary design tool. Implementing a bank of filters increases the robustness of the LQG controller when uncertainties exist in the system model, whereas the moving bank is utilized to reduce the computational load. Several reduced-order models are developed from …

Analysis Of The Effects Of Wake Passage On Heat Transfer In A Linear Turbine Cascade, Kevin S. Allen

Theses and Dissertations

This study investigated the effect of wake passage on the heat transfer in a linear turbine cascade. The apparatus used was the Air-Force Institute of Technology linear Turbine Cascade Test Facility (TCTF). The TCTF was fitted with a be Pulley system to facilitate a series of translating bars. The bars, when passed d upstream of the cascade, created a series of wakes. The parameters varied were freestream model Reynolds number and bar conditions, i.e. , bars in, bars out, and bar passing frequency. One blade in the TCTF was instrumented to allow pressure and temperature measurements at discrete points on …

The Effects Of Optical Feedback On Polarization Of Vertical Cavity Surface Emitting Lasers, Gregory J. Vansuch

Theses and Dissertations

Vertical Cavity Surface Emitting Lasers VCSELs are a type of semiconductor laser with a cavity oriented orthogonally to the planes of material growth. These lasers differ from conventional edge emitting lasers in several important ways. They have symmetric output beams and they are easily built into two dimensional arrays, making them very attractive as photonic components. The characteristic of interest in this thesis is polarization. While the asymmetric cavities of edge emitters exhibit a clear preference for light polarized in a particular direction, the cylindrically symmetric cavity of a VCSEL has no clear preference. Therefore, it should be relatively easy …