| Multiple Model Adaptive Estimation and Control Redistribution Performance on the VISTA F-16 During Partial Actuator Impairments. Volume 1 |
DEC 97 |
135 pages |
| Authors:
Curtis S. Clark; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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 | Multiple Model Adaptive Estimation with Control Reconfiguration (MMAE/CR) capability to estimate and compensate for partial actuator failures, or "impairments" is investigated using the high-fidelity, nonlinear, six-degree- of-freedom, VISTA F-16 simulation which currently resides on the Simulation Rapid-Prototyping Facility (SRF). After developing a model for inserting partial actuator impairments into the VISTA F-16 truth model, research begins with a battery of single actuator impairment tests. This stage of research explores the ... |
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| Evaluation of a Maximum A-Posteriori Slope Estimator for a Hartmann Wavefront Sensor |
DEC 1997 |
123 pages |
| Authors:
Troy B. Van Caster; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Current methods for estimating the wavefront slope at the aperture of a telescope using a Hartmann wavefront sensor are based upon a centroid shift estimator. The centroid shift estimator determines the displacement, or shift, of the centroid off the optical axis using a moment calculation of the intensity distributions recorded in each subaperture. This centroid shift is proportional to the average slope of the wavefront in each subaperture. A maximum ... |
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| Message-Bundle Converting in Intenet Protocol Multicast-Based High Level Architecture Exercises |
DEC 1997 |
113 pages |
| Authors:
Tracy A. Bobo; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| The Department of Defense is pushing for more wide-spread and realistic interactive training simulations which increases the demand on network capacity and resources. While network bandwidth is a measurable resource, packet bandwidth, or the number of packets-per-second (Pk/s) a host can handle, is a shifting commodity. This research analyzes host performance characteristics under varying data loads. The hosts include SGI single and multi-processor systems and Intel Pentium platforms using both ... |
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| Speaker Verification in the Presence of Channel Mismatch Using Gaussian Mixture Models |
DEC 1997 |
69 pages |
| Authors:
Robert B. Reid; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| A channel compensation method is sought for use in speaker identification (ID) and verification applications under matched and mismatched training and testing conditions. This work expands on previous work on matched conditions by investigating three techniques on matched and mismatched conditions using the TIMIT and NTIMIT speech databases. First, previous results on 168 speakers are reproduced for matched conditions using Gaussian mixture models (GMM) and mel-frequency cepstral coefficients. Next, cepstral ... |
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| Atmospheric Induced Errors in Space-Time Adaptive Processing |
DEC 1997 |
139 pages |
| Authors:
Vinod D. Naga; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| This thesis examines the effects of atmospheric turbulence-induced phase perturbations on the performance of ground-based Space-Time Adaptive Processing (STAP) systems. Both Fully Adaptive Joint Domain Optimum and Partially Adaptive Factored-Time Space processing methods are examined. This thesis concentrates on the turbulence effects on STAP applied to ground-based arrays. This thesis further focuses on the capability of STAP to resolve targets at low elevation angles in the presence of turbulence. Only ... |
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| Optimal Orbit Insertion Strategies Using Combined High and Low Thrust Propulsion Systems |
DEC 1997 |
101 pages |
| Authors:
Darren W. Johnson; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Low thrust electric propulsion systems are becoming sufficiently mature to consider their use as primary propulsion for orbital transfer in place of high thrust chemical systems. Instead of facing an either/or situation, it may be advantageous to use both types. This effort demonstrates a technique for finding orbital transfer strategies that use both high and low thrust propulsion systems and which result in optimal tradeoffs of the performance parameters cost ... |
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| Atmospheric Turbulence Scintillation Effects on Wavefront Tilt Estimation |
DEC 1997 |
99 pages |
| Authors:
James A. Louthain; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| A new atmospheric turbulence screen generator is developed for use in performance calculations of adaptive optics systems valid over a wide range of atmospheric turbulence parameters. The screen generator accounts for diffraction effects caused by weak turbulence and incorporates the phase, amplitude, and cross statistics of the perturbed optical field. The wavefront's phase and amplitude perturbations are taken from the correlation functions developed by Lee and Harp and the cross ... |
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| Analytic Transfer Function of the Forward Propagation of Diffuse Photon Density Waves in Turbid Media with an Embedded Spherical Inhomogeneity |
DEC 1997 |
126 pages |
| Authors:
Deborah L. Lasocki; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Diffusing photons can be used to detect and localize optical inhomogeneities embedded in turbid media such as clouds, fog, paint and human tissue. This thesis shows that a transfer function derived from an analytic solution of the Helmholtz equation can completely characterize in three dimensions the perturbations in the forward propagation phenomena caused by a spherical defect object in a multiple-scattering medium. Two models of the forward propagation behavior of ... |
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| Effects of Near-Field Scatterers on Space-Time Adaptive Processing |
DEC 1997 |
129 pages |
| Authors:
Jonathan W. Fitton; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Near-field scatterers, such as the wing of an airplane, can affect the ability of the processor to null out clutter and jammer signals. The target, clutter, and jammer signals will reflect off the near-field scatterers into the array and appear to be coming from a direction different from their true sources. This thesis develops a theoretical model for the direct path and scattered path signals from the target, clutter, and ... |
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| A Wire Antenna Designed for Space Wave Radiation Over the Earth Using a Genetic Algorithm |
DEC 1997 |
115 pages |
| Authors:
Brian S. Sandlin; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| A wire antenna is designed for optimal performance at low elevation angles in the presence of a lossy half-space. A simple genetic algorithm (GA) and GENOCOP III software are each integrated with Numerical Electromagnetics Code Version 4.1 (NEC4.1) to optimize a wire antenna geometry for multiple |
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| A Reconfigurable Superscalar Architecture |
DEC 97 |
293 pages |
| Authors:
Christopher B. Mayer; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| The invention of the Field Programmable Gate Array (FPGA) has led to a number of interesting developments. One is the idea of providing custom hardware support for applications running on a computer. These reconfigurable computers have been shown to decrease the execution time for some applications. Based on past results, attention has subsequently turned to using reconfigurable computing in general-purpose computers (e.g. desktop and workstation environments). This thesis develops a ... |
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| Breast Cancer Mass Detection Using Difference of Gaussians and Pulse Coupled Neural Networks |
DEC 97 |
76 pages |
| Authors:
Donald A. Cournoyer; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| CAD, serving as a second reader, has been shown to improve the success of radiologists at detecting breast cancer. This thesis will develop a new algorithm to identify masses in mammograms. The system developed for this thesis will be capable of assisting a radiologist in making decisions. |
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| A Dispersive Scattering Center, Parametric Model for 1-D ATR |
DEC 97 |
66 pages |
| Authors:
Dane F. Fuller; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| The dispersive scattering center (DSC) model characterizes high- frequency backscatter from radar targets as a finite sum of localized scattering geometries distributed in range, these geometries, along with their relative locations, can be conveniently used as features in a one-dimensional automatic target recognition (ATR) algorithm. The DSC model's type and range parameters correspond to geometry and distance features according to the geometric theory of diffraction (GTD). Since these parameters are ... |
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| Secondary Data Support and Non-Homogeneities in Space-Time Adaptive Processing |
DEC 1997 |
202 pages |
| Authors:
Todd B. Hale; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| One of the primary problems with the application of Space-Time Adaptive Processing (STAP) techniques is secondary data support for the interference plus noise covariance matrix estimate. Reed has shown the required secondary data support to achieve performance within 3 dB of optimal SINR is approximately equal to twice the degrees of freedom (DOF) used in the algorithm. Reed proved this rule for Sample Matrix Inversion (SMI) techniques. A concern arises ... |
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| Orbit Estimation Using Track Compression and Least Squares Differential Correction |
DEC 97 |
152 pages |
| Authors:
Vincent J. Chioma; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| This thesis develops two methods of compressing a track of radar observations of a satellite into a single state vector and associated covariance matrix, and a method of estimating orbits using results from multiple tracks. The track compression uses least squares differential correction to determine a state vector at the central observation time. The resulting state vectors and covariance matrices are then used to estimate the satellite's orbit, also using ... |
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| The Virtual Spaceplane: Integrating Multiple Motion Models and Hypertext in a Virtual Environment |
DEC 1997 |
121 pages |
| Authors:
Troy D. Johnson; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| The Air Force is currently investigating the possibility of developing a manned vehicle capable of operating in space. This Military Spaceplane (MSP) will be capable of ascent to low-earth orbit and maneuvering while in orbit. The goal of this research involved creating the Virtual Spaceplane (VSP), a virtual environment (VE) simulator for the MSP. This thesis examines two ideas significant to virtual environments and cockpit design: multiple motion models and ... |
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| An Examination of Multi-Tier Designs for Legacy Data Access |
DEC 97 |
151 pages |
| Authors:
Michael L. Acker; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| This work examines the application of Java and the Common Object Request Broker Architecture (CORBA) to support access to remote databases via the Internet. The research applies these software technologies to assist an Air Force distance learning provider in improving the capabilities of its World Wide Web-based correspondence system. An analysis of the distance learning provider's operation revealed a strong dependency on a non-collocated legacy relational database. This dependency limits ... |
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| Collisional Broadening of Spectral Lines in the X --> b System of O2 and the First Vibrational Band of NO by the Noble Gases |
DEC 97 |
133 pages |
| Authors:
John J. Cornicelli; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Collisional broadening of the rotational spectral lines of the X to b system of O2 and the first vibrational band of NO by the noble gases is examined by Fourier transform spectroscopy. Peaks of the individual rotational lines are modeled with a Voigt function, from which Lorentzian half widths are extracted. Lorentzian widths are plotted vs. pressure of foreign gas, from which the pressure broadening coefficients and pressure broadening cross ... |
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| A Comparative Analysis of Networks of Workstations and Massively Parallel Processors for Signal Processing |
DEC 97 |
151 pages |
| Authors:
David C. Gindhart; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| The traditional approach to parallel processing has been to use Massively Parallel Processors (MPPs). An alternative design is commercial-off- the-shelf (COTS) workstations connected to high-speed networks. These networks of workstations (NOWs) typically have faster processors, heterogeneous environments, and most importantly, offer a lower per node cost. This thesis compares the performance of MPPs and NOWs for the two-dimensional fast Fourier transform (2-D FFT). Three original, high-performance, portable 2-D FFTs have ... |
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| Modeling and Simulation Support for Parallel Algorithms in a High-Speed Network |
DEC 1997 |
159 pages |
| Authors:
Dustin E. Yates; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| This thesis investigates the ability of a simulation model to compare and contrast parallel processing algorithms in a high-speed network. The model extends existing modeling, analysis, and comparison of parallel algorithms by providing graphics based components that facilitate the measurement of system resources. Simulation components are based on the Myrinet local area network standard. The models provide seven different topologies to contrast the performance of five variations of Fast Fourier ... |
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| Requirements, Design and Prototype of a Virtual User Interface for the AFIT Virtual Spaceplane |
DEC 1997 |
157 pages |
| Authors:
John M. Lewis; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| The United States Air Force is evaluating the feasibility of designing a military spaceplane capable of accomplishing military objectives from a low earth orbit and atmospheric flight regimes. Current efforts are involved in determining the scientific, operational. and budgetary constraints associated with this concept. This thesis looks at the exploration of new interface techniques associated with the design of a virtual spaceplane and is a subset of the overall virtual ... |
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| An Analytical Method to Calculate Activity from Measurements Affected by Coincidence Summing |
DEC 97 |
198 pages |
| Authors:
Anthony P. Popovich; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| An analytical method is developed and applied to find the activities of two radioisotopes based on measurements influenced by true coincidence summing. The method incorporates the solid angle subtended by the detector, the macroscopic cross sections of the materials present, the absolute peak and total efficiencies of the detector, and the modes and probabilities of decay of the radioisotope. With this information, the method corrects for both summing-in and summing-out ... |
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| Reduced Computational Cost, Totally Symmetric Angular Quadrature Sets for Discrete Ordinates Radiation Transport |
DEC 1997 |
148 pages |
| Authors:
Joseph M. Oder; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Several new quadrature sets for use in the discrete ordinates method of solving the Boltzmann neutral particle transport equation are derived. These symmetric quadratures extend the traditional symmetric quadratures by allowing ordinates perpendicular to one or two of the coordinate axes. Comparable accuracy with fewer required ordinates is obtained. Quadratures up to seventh order are presented. The validity and efficiency of the quadratures is then tested and compared with the ... |
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| Applying Flywheel Energy Storage to Solar Electric Orbital Transfers |
DEC 97 |
94 pages |
| Authors:
Mark W. Marasch; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| This study investigated the application of flywheel energy storage to minimum time, constant thrust orbital maneuvers using electric propulsion. The advantages of using stored energy to continue electric thruster operations while in eclipse were explored. The boundary value problems for several schemes of energy use were examined, and numerical solutions were found. Results of simulations utilizing energy storage were compared to results without energy storage. Schemes incorporating energy storage were ... |
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| Developing a Corpus Specific Stoplist Using Quantitative Comparison |
DEC 97 |
138 pages |
| Authors:
Craig N. Berg; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| We have become overwhelmed with electronic information and it seems our situation is not going to improve. It is becoming increasingly common for people to work with information on a daily basis. We seem to spend more and more time looking for information, and it is taking longer because more information is available. This thesis will look at how we can provide faster access to the information we want to ... |
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| Forecasting Methodologies for USAF Facility Maintenance and Repair Funding Requirements |
DEC 97 |
142 pages |
| Authors:
Gregory R. Ottoman; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Eighteen methodologies for forecasting facility maintenance and repair funding requirements were investigated and analyzed to determine which methodology is best suited for use by the United States Air Force (USAF). The literature review identified four primary factors, or criteria, that determine facility maintenance and repair funding requirements. The methodologies were scored against the four criteria with respect to their appropriate application to USAF requirements. An analysis of dominance was accomplished; ... |
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| Optimal Pulsed Pumping for Remediation of Aquifiers when Sorption is Rate-Limited |
DEC 97 |
186 pages |
| Authors:
Lawrence J. Schmitt; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| A variational optimization technique is developed to acquire an optimal schedule of pulsed pumping operations for use at existing pump-and-treat aquifer remediation sites. The optimization problem is stated as a minimization of a generic management objective functional, constrained by the contaminant transport equations in two-dimensional or three-dimensional flow models which account for rate-limited sorption. The two-dimensional case is fully developed and a first-order rate equation is used to describe the ... |
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| A Validation of the Parameterized Real-Time Ionospheric Specification Model (PRISM) Version 1.7B |
NOV 97 |
129 pages |
| Authors:
Shawn D. Filby; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| The most current version of the Parameterized Real-time Ionospheric Specification Model (PRISM), version 1.7b, was validated using Digital Ionospheric Sounding System (DISS) measurements of F2 layer critical frequency (foF2) and F2 peak electron density height (hmF2) as the "ground truth." PRISM was executed, first, with no real-time input parameter and, second, with Global Positioning System (GPS) Total Electron Content (TEC) measurements as the sole real-time parameter. Hourly values of hmF2 ... |
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| Failure Characteristics of Sandwich Plates Under Static and Dynamic Loading |
OCT 1997 |
254 pages |
| Authors:
A. N. Palazotto; L. N. Grummadi; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Laminated sandwich plate constructions are extensively used in various aerospace and industrial applications. However, these plates are prone to many defects. Specifically, their resistance to impact is a major concern. Impact can significantly reduce the strength and stiffness of the structure. Studying various aspects that can be used to improve the impact resistance of sandwich plates is the objective of this report. Two different sandwich models are studied. First, the ... |
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| Scheduling and Sequencing Arrivals to a Stochastic Service System |
OCT 1997 |
270 pages |
| Authors:
Peter M. Bosch; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Optimization of scheduled arrival times to an appointment system is approached from the perspectives of both queueing and scheduling theory. The appointment system is modeled as a one-server, first-come-first-served, transient queue with independent, distinctly distributed service times and no- show rates. If a customer does show, it is assumed to be punctual. The cost of operating the appointment system is a convex combination of customers' waiting times and the server's ... |
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| Shock Waves in Nonequilibrium Gases and Plasmas |
OCT 97 |
274 pages |
| Authors:
William M. Hilbun; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| An analysis and assessment of three mechanisms describing plasma/ shock wave interactions was conducted under conditions typically encountered in a weakly ionized glow discharge. The mechanisms of ion-acoustic wave damping, post-shock energy addition and thermal inhomogeneities were examined by numerically solving the Euler equations with appropriate source terms adapted for each mechanism. Ion-acoustic wave damping was examined by modeling the partially ionized plasma as two fluids in one spatial dimension ... |
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| Fact Book: AFIT Research, Cost and Benefit |
OCT 97 |
172 pages |
| Authors:
Charles J. Bridgman; David K. Vaughan; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Data are presented on the cost and on the benefits of research performed by the graduate students and faculty of the resident schools of the Air Force Institute of Technology (AFIT) at Wright Patterson AFB, Ohio (WPAFB). Costs are calculated by allocating direct and indirect costs of operation to the research function. Research costs per student year for 1996 were found to be $17,809. This is benchmarked against data from ... |
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| Parameter Estimation for Real Filtered Sinusoids |
SEP 97 |
192 pages |
| Authors:
Daniel R. Zahirniak; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| This research develops theoretical methods for parameter estimation of filtered, pulsed sinusoids in noise and demonstrates their effectiveness for Electronic Warfare (EW) applications. Within the context of stochastic modeling, a new linear model, parameterized by a set of Linear Prediction (LP) coefficients, is derived for estimating the frequencies of filtered sinusoids. This model is an improvement over previous modeling techniques since the effects of the filter and the coefficients upon ... |
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| Hybrid Quantum and Molecular Mechanics Embedded Cluster Models for Chemistry on Silicon and Silicon Carbide Surfaces |
97 |
336 pages |
| Authors:
James R. Shoemaker; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Fabrication of silicon carbide (SiC) semiconductor devices are of interest for aerospace applications because of their high-temperature tolerance. Growth of an insulating SiO2 layer on SiC is a poorly understood process, and sometimes produces interface defects that degrade device performance. Accurate theoretical models of surface chemistry, using quantum mechanics (QM), do not exist because of the huge computational cost of solving Schroedinger's equation for a molecular cluster large enough to ... |
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| The Rational Resolution Analysis: A Generalization of Multiresolution Analyses with Application to the Specific Emitter Identification Problem |
DEC 1996 |
179 pages |
| Authors:
Bruce P. Anderson; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| The rational resolution analysis (RRA) is introduced and developed as a generalization of the integer, dilation multiresolution analyses (MRA) developed by Mallat and Meyer. Rational dilation factors are achieved by relaxing the condition on MRAs that successive approximation spaces be embedded. Conditions for perfect reconstruction are discussed and it is shown that perfect reconstruction is possible with specific constraints on the scaling function: the scaling filter must have its roots ... |
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| A Systems Engineering Approach to Aircraft Kinetic Kill Countermeasure Technology: Development of an Active Air Defense System for the C/KC-135 Aircraft. Volume 2 |
DEC 1995 |
282 pages |
| Authors:
Mark C. Cherry; Bruce R. Dewitt; Christopher G. Dusseault; Joel J. Hagan; Brian S. Peterson; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Modern Surface to Air Missiles (SAMs) present a significant threat to today's military and civilian aircraft. Current countermeasure systems such as flares and chaff rely on decoying the missile threat and do not provide adequate protection against advanced computerized missiles (Schaffer, 1993:1). An aircraft defense system that actively seeks out and defeats an incoming missile by placing a physical barrier in the missile's path offers a promising alternative to current ... |
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| EASY-SIM: A Visual Simulation System Software Architecture with an ADA 9X Application Framework |
DEC 1994 |
163 pages |
| Authors:
Jordan R. Kayloe; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Software architectures increase productivity when used as the basis for developing applications in a problem domain. This thesis describes the creation of Easy-Sim, an object-oriented software architecture for visual simulation systems, and its corresponding implementation as an application framework in Ada 9X. The research built upon ObjectSim, an existing object- oriented simulation architecture implemented as a application framework. Both ObjectSim and Easy-Sim operate on Silicon Graphics platforms and use the ... |
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| Applicability of an Activity Based Cost System in Government Service Organizations |
SEP 1994 |
303 pages |
| Authors:
Robert W. Callahan; Daniel A. Marion; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| This research focused on the applicability of Activity-Based Cost (ABC) systems within government service organizations. ABC implementation efforts within other government organizations were first examined to determine what information short caused managers to consider ABC implementation. Next, archival analysis was conducted within the case study organization to determine if the same accounting information shortfalls existed. An ABC system was then implemented within the case study organization. ABC information was compared ... |
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| A Monte Carlo Study of the Raw and Normal Varimax Rotation Criterion in Factor Analysis |
23 MAR 1993 |
113 pages |
| Authors:
Willam M. Ibinson; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Factor analysis is a multivariate statistical procedure for analyzing and reducing large data sets. Many factor analysis schemes and techniques are available that lead to strikingly different results from the same data. This research effort used a Monte Carlo approach to investigate the properties of two rotation methods for simple structure, Kaiser's raw and normal varimax criterion. Data sets were developed from a set of contrived experimental factor patterns by ... |
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| Characterization of Laboratory Generated Turbulence by Optical Phase Measurements |
23 MAR 1993 |
173 pages |
| Authors:
Eric P. Magee; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| The resolution achieved by an optical imaging system in the presence of the random effects of the atmosphere is severely degraded from the theoretical diffraction limit. Techniques exist for recovering near diffraction limited performance of an imaging system in the presence of atmospheric turbulence. As opposed to laboratory testing, testing image enhancement techniques in the Earth's atmosphere imposes many limitations. Unfavorable weather conditions could result in the loss of time ... |
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| A Statistical Analysis of Terrorism and Instability in Latin America |
MAR 1993 |
143 pages |
| Authors:
Juan A. Hurtado; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| In this research the effect of socioeconomic factors on terrorism and government instability in Latin America are studied. A commonly held opinion is that terrorism and instability are caused by repressive conditions. The objective of this research was to generate a methodology to forecast terrorism and instability given certain socioeconomic indicators. This methodology was generated for individual countries, two groups of countries, and a composite developing country. A set of ... |
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| AFITBUNKI: A Modified Iterative Code to Unfold Neutron Spectra from Bonner Sphere Detector Data |
MAR 1993 |
118 pages |
| Authors:
Sean C. Miller; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| The neutron spectrum unfolding code BUNKI, developed at the Naval Research Laboratory in 1983, was modified to incorporate a finer energy group structure, seven initial-guess spectra, and new dose conversion factors. The modified code, AFITBUNKI, unfolds spectra into 54 energy groups between 10(exp- 7) and 14.92 MeV. The code calculates fluence, absorbed dose, percent of effective dose equivalent, and percent of ambient dose equivalent as a function of neutron energy. ... |
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| Predicting the Productive Capacity of Air Force Aerospace Ground Equipment Personnel Using Aptitude and Experience Measures |
MAR 1993 |
140 pages |
| Authors:
Robert S. Faneuff; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| This study investigated the effects of mechanical aptitude and job experience on the job performance of 204 Air Force Aerospace Group Equipment (AGE) mechanics. Job performance was expressed as productive capacity (PC), which is derived from estimated performance times on job tasks. PC measures were derived for 50 tasks typically performed by airmen in the specialty. Aptitude measures took the form of Mechanical percentile composite scores on the Armed Services ... |
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| Models for the Optimization of Air Refueling Missions |
MAR 1993 |
163 pages |
| Authors:
Clayton H. Pflieger; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| This research follows A. Yamani's work on the problem of minimizing total fuel costs for airlift missions that require in-flight refueling. Yamani's major assumptions were removed and the resulting enhanced formulation was applied the the original problem and the related problem of maximizing allowable cabin load. This optimization is accomplished selecting the rendezvous point and initial fuel for each aircraft. The formulation considers a C-141B airlifter refueled once by a ... |
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| Theater Airlifter Survivability on the Ground |
MAR 1993 |
150 pages |
| Authors:
Michael A. Silver; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| Airlifter attrition can severely decrease the throughput of cargo during extended airlift operations. Much work has been done to enhance the tactical airlifter survivability in the air but little study has gone into airlifter survivability on the ground. This thesis develops a method to measure the threat to parked aircraft from ground weapons. Specific scenarios cover airlifter mobility on the ground, time to off-load cargo, short-field takeoff capability and attack ... |
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| Understanding the Nature of Bureaucracy: An Integration of the Organizational and Public Choice Approaches |
MAR 1993 |
130 pages |
| Authors:
Rodney G. Vernon; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| Bureaucracy is a term that has taken on different meanings in the academic literature since its inception. Vincent de Gournay first coined the term during the eighteenth century to describe the illnesses of rule by officials. Since that time, the term has evolved in organizational theory to describe a form of rational hierarchical organization in the public and private sector and at the same time, the public choice school describes ... |
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| Scheduling Air Mobility Command's Channel Cargo Missions |
MAR 1993 |
134 pages |
| Authors:
Gregory S. Rau; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| Through the use of a linear programming model, this research revised the initial schedule for AMC's channel cargo missions to eliminate any excess delay enroute by minimizing the cumulative, weighted time-in-system for all cargo, according to a given cargo flow. In fact, the revised schedule minimizes any assigned nonnegative weighting of the time-in-system, due to the properties of equivalent measures of performance. When combined with Step One of a proposed ... |
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| Identification of Significant Outliers in Time Series Data |
MAR 1993 |
148 pages |
| Authors:
Keri L. Robinson; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| This thesis examines the feasibility of using least median of squares (LMS) procedure applied to a reweighted least squares (RLS) autoregression model to identify significant outliers in time series data. The time series were analyzed for data points that were outliers. In order to perform detailed analysis on an outlier. the analyst must be able to determine that an outlier data point is significantly different from normally distributed data. This ... |
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| Including Maximum Sustained Wind Speed in a Time Series Model to Forecast Hurricane Movement |
MAR 1993 |
155 pages |
| Authors:
Timothy B. Mott; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| Techniques for applying time series fundamentals to forecasting hurricane movement are thoroughly examined in this research. The objectives are: (1) to modify Dr. Thomas Curry's threshold autoregressive time series model to improve its ability to forecast hurricane movement, (2) to forecast the maximum sustained wind speed for a hurricane, and (3) to identify if wind speed should be included as an explanatory variable to aid in forecasting hurricane movement. Eleven ... |
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| Optimal Silo Attack Plan for the Red Integrated Strategic Offensive Plan (RISOP) |
MAR 1993 |
139 pages |
| Authors:
Richard C. Pace; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| The Joint Staff Directorate for Force Structure, Resources, and Assessment (J-8) sought a procedure which could be used to generate an optimal missile allocation for the silo attack portion of the Red Integrated Strategic Offensive Plan (RISOP). Their current solution procedure is a manual heuristic which is time-consuming and is not guaranteed to lead to an optimal solution. J- 8 defines an optimal solution as a feasible solution which minimizes ... |
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