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Air Force Institute of Technology

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Estimating Kc-137 Aircraft Ownership Costs In The Brazilian Air Force, Ulisses O. Bonasser Jun 1997

Estimating Kc-137 Aircraft Ownership Costs In The Brazilian Air Force, Ulisses O. Bonasser

Theses and Dissertations

This research addresses the estimation of operation and support (O&S) costs of the Brazilian Air Force KC-137 aircraft. BAF lacks an established set of procedures for computing ownership costs of such aircraft, which prejudices the elaboration of cost-benefit analysis and allocation of budget resources. The purpose of the study is to develop an O&S cost breakdown structure and a set of cost estimating equations that will be used to estimate the ownership costs of the KC-137 aircraft during their expected service life.

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Physiologically-Based Vision Modeling Applications And Gradient Descent-Based Parameter Adaptation Of Pulse Coupled Neural Networks, Randy P. Broussard Jun 1997

Physiologically-Based Vision Modeling Applications And Gradient Descent-Based Parameter Adaptation Of Pulse Coupled Neural Networks, Randy P. Broussard

Theses and Dissertations

In this research, pulse coupled neural networks (PCNNs) are analyzed and evaluated for use in primate vision modeling. An adaptive PCNN is developed that automatically sets near-optimal parameter values to achieve a desired output. For vision modeling, a physiologically motivated vision model is developed from current theoretical and experimental biological data. The biological vision processing principles used in this model, such as spatial frequency filtering, competitive feature selection, multiple processing paths, and state dependent modulation are analyzed and implemented to create a PCNN based feature extraction network. This network extracts luminance, orientation, pitch, wavelength, and motion, and can be cascaded …

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Optimization Considerations For Adaptive Optics Digital Imagery Systems, Robert T. Brigantic Jun 1997

Optimization Considerations For Adaptive Optics Digital Imagery Systems, Robert T. Brigantic

Theses and Dissertations

This dissertation had three objectives. The first objective was to develop image quality metrics that characterize Adaptive Optics System (AOS) performance. The second objective was to delineate control settings that maximize AOS performance. The third objective was to identify and characterize trade-offs between fully and partially compensated adaptive. For the first objective, three candidate image quality metrics were considered: the Strehl ratio, a novel metric that modifies the Strehl ratio by integrating the modulus of the average system optical transfer function to a 'noise-effective-cutoff' frequency at which some specified image spectrum signal-to-noise-ratio level is attained, and the noise-effective-cutoff frequency. It …

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Kinetics And Spectroscopy Of Brno, Patrick E. Godfrey Jun 1997

Kinetics And Spectroscopy Of Brno, Patrick E. Godfrey

Theses and Dissertations

The infrared spectra and photochemistry of nitrosyl bromide, BrNO, are important to characterizing the performance of a recently demonstrated Br(2P1/2)-NO(v=2 → v=1) transfer laser pumped by photolysis of iodine molecules. This wavelength agile, mid-infrared laser may be a desirable source for remote sensing and infrared countermeasures missions. Nitrosyl bromide also plays a role in the destruction of stratospheric ozone. The kinetics of BrNO formation and destruction were examined using time-resolved photolysis techniques. The equilibrium constant for the dark reaction Br2 + 2NO (reversible reaction) 2BrNO was determined as Keq 168 ± 23 /atm and …

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Thickness Effects On A Cracked Aluminum Plate With Composite Patch Repair, Joel J. Schubbe Jun 1997

Thickness Effects On A Cracked Aluminum Plate With Composite Patch Repair, Joel J. Schubbe

Theses and Dissertations

Post-repair fatigue crack growth was investigated in 3.175, 4.826, and 6.35 mm thick aluminum panels asymmetrically repaired with boron/epoxy composite patches bonded to the plates with FM73 sheet adhesive. Patches were uniaxial with patch to panel stiffness ratios ranging from 0.46 to 1.3. Experimental fatigue tests were carried out at 120 MPa, R=0.1, and 10 Hz (sinusoidal) to measure patched and unpatched face crack lengths, center crack opening displacements, and selected strains. Crack growth data was acquired using optical, eddy current, and post-test analysis methods. Crack growth rates were calculated using the incremental polynomial method. A three-layer Mindlin plate finite …

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Evaluation And Application Of Space Telescope Aberration Sensing Using Phase Diversity, David J. Lee Apr 1997

Evaluation And Application Of Space Telescope Aberration Sensing Using Phase Diversity, David J. Lee

Theses and Dissertations

Due to mechanical aspects of fabrication, launch, and operational environment, space telescope optics can suffer from unforeseen aberrations, detracting from their intended diffraction-limited performance goals. This dissertation gives the results of simulation and theoretical studies designed to explore how wavefront aberration information for such "nearly diffraction-limited" telescopes can be estimated via the Gonsalves (least-squares) phase diversity technique. In traditional phase diversity, aberrations are estimated from two images—one conventional, focused image and one image that has been defocused by a known amount. These studies are original and significant in that this effort represents the first time the effects of photon noise …

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The Application Of Statistical Process Control To Departure Reliability Improvement, Liu W. Chieh Mar 1997

The Application Of Statistical Process Control To Departure Reliability Improvement, Liu W. Chieh

Theses and Dissertations

This research effort focuses on applying statistical process control (SPC) techniques to the departure reliability improvement process for Air Mobility Command, Mission Reliability Office. Basic SPC methods, including Pareto analysis, cause and effect diagrams, and control charts are determined to be effective tools for analyzing and assessing departure reliability. In addition, two more alternative measures of effectiveness for departure reliability are evaluated and compared using AMC's data. SPC methods are also shown to be useful in assessing in performance and in determining the reporting frequency for on-time performance information. Additional statistical analyses are conducted, including on-way analyses of variance, hypothesis …

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Electromagnetic Scattering From A Cavity In A Ground Plane: Theory And Experiment, William D. Wood Jr. Mar 1997

Electromagnetic Scattering From A Cavity In A Ground Plane: Theory And Experiment, William D. Wood Jr.

Theses and Dissertations

The electromagnetic scattering from an arbitrarily shaped open cavity embedded in a perfectly conducting, infinite ground plane is examined. The cavity is filled with a linear, isotropic, homogeneous material. The fields in the cavity interior and above the ground plane are expressed in terms of the tangential fields on the cavity surface and aperture. A coupled set of three integral equations is developed governing the tangential fields on the aperture and cavity surface. The support of the unknown tangential fields is finite. A moment-method based algorithm to approximate the solution to the integral equations for axisymmetric geometries is developed. The …

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System Comparison Procedures For Automatic Target Recognition Systems, Anne E. Catlin Mar 1997

System Comparison Procedures For Automatic Target Recognition Systems, Anne E. Catlin

Theses and Dissertations

Estimating the performance of an automatic target recognition (ATR) system in terms of probability of successful target identification involves extensive image collection and processing, which can be very time-consuming and expensive. We investigate the Wald sequential test for the difference in two proportions as a sample size-reducing alternative to ranking and selection and the classical method of comparing binomial confidence intervals. The test is modified for the multiple pairwise comparison of four systems, and is applied to actual data to compare different configurations of the Moving and Stationary Target Acquisition and Recognition (MSTAR) System.

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Automatic Digital Processing For Calibration Data Of Open Skies Treaty Sensors, Donna D. Keating Mar 1997

Automatic Digital Processing For Calibration Data Of Open Skies Treaty Sensors, Donna D. Keating

Theses and Dissertations

The Open Skies Treaty provides guidelines allowing participants to fly in air space over other participants' countries to monitor strategic military placement and development. The treaty restricts the ground size of the smallest detail recorded by these aerial imaging systems to any size larger than 30 cm. This restriction is enforced by placing a lower limit on the altitude at which a participating aircraft can fly and it is computed as the value of Hmin. Current techniques rely on human photographic interpreters to select the value of Hmin for every calibration pass and is very resource intensive. The Open Skies …

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Alternative Implementations Of Expanding Algorithm For Multi-Commodity Spatial Price Equilibrium, Yu-Shen Ke Mar 1997

Alternative Implementations Of Expanding Algorithm For Multi-Commodity Spatial Price Equilibrium, Yu-Shen Ke

Theses and Dissertations

This thesis presents an algorithm based on the expanding algorithm to solve spatial price equilibrium problems for three different models: perfect competition, monopoly, oligopoly. The expanding algorithm is used to solve the linear single commodity spatial price equilibrium problem for perfectly competitive markets. In this thesis, we consider the general multi-commodity spatial price equilibrium problems with all nonlinear functions, and variable shipping cost. We also show that more commodities in total are shipped, and there is more congestion, especially in oligopoly model.

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Modeling And Analyzing The Effect Of Ground Refueling Capacity On Airfield Throughput, W. Heath Rushing Mar 1997

Modeling And Analyzing The Effect Of Ground Refueling Capacity On Airfield Throughput, W. Heath Rushing

Theses and Dissertations

This thesis develops five analytical models to understand the current ground refueling process, to optimize the airfield configuration and to determine the refueling policy which maximizes throughput, the primary measure of airfield efficiency. This study models the airfield refueling process as a continuous time Markov process to adequately represent the inherent stochastic nature of the transitory ground refueling system and provide an analytical evaluation of various airfield configurations. Also, the study provides an optimal refueling policy to minimize the number of aircraft on the ground which in turn minimizes the average amount of time aircraft spend on the ground in …

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Analyzing And Improving Stochastic Network Security: A Multicriteria Prescriptive Risk Analysis Model, David L. Lyle Mar 1997

Analyzing And Improving Stochastic Network Security: A Multicriteria Prescriptive Risk Analysis Model, David L. Lyle

Theses and Dissertations

This research optimized two measures of network security by hardening components and improving their reliability. A common measure of effectiveness (MOE) for networks is statistical reliability, which ignores the effects of hostile actions. A new MOE which includes hostile actions was developed. Both measures require component reliability functions, derived using fault trees. Fuzzy Logic and Monte Carlo simulation were used to quantify uncertainty. Results from the model are compared to traditional Risk Assessment results.

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Development And Implementation Of An Isentropic Potential Vorticity Algorithm For Use At Air Force Global Weather Center, Jay B. Desjardins Jr. Mar 1997

Development And Implementation Of An Isentropic Potential Vorticity Algorithm For Use At Air Force Global Weather Center, Jay B. Desjardins Jr.

Theses and Dissertations

This thesis presents and validates methods for calculating isentropic potential vorticity (IPV) and applies these methods in software programs planned for implementation at the Air Force Global Weather Center (AFGWC). The IPV programs will provide Air Force Weather forecasters additional tools to diagnose atmospheric kinematics and understand atmospheric dynamics. A FORTRAN program is recommended using mandatory-level isobaric data projected to be available on AFGWC computer systems, specifically, from the Navy Operational Global Atmosphere Prediction System and Medium Range Forecast models. Program development and analysis consists of three main steps: (1) data retrieval; (2) IPV calculations; and, (3) interpolation to an …

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Moisture Sensitivity Of Contrail Forecast Algorithms, Allen C. Rabayda Mar 1997

Moisture Sensitivity Of Contrail Forecast Algorithms, Allen C. Rabayda

Theses and Dissertations

This thesis looked at using new relative humidity (RH) climatologies to improve the Air Force Global Weather Center's (AFGWC) contrail forecasts. To study the effect of the new RH climatolgies, the currently used empirical relative humidity (RH) profile is replaced with a more accurate climatological one, the Stratospheric And Gaseous Experiment II (SAGE II). The study begins by examining accuracy and bias of forecast contrail bases generated by the empirical and SAGE II RH profiles on 42 days. Both sets of forecast bases are shown to be statistically similar with a series of hypothesis tests. Additional RH profiles, from 0% …

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Advances In Time-Domain Electromagnetic Simulation Capabilities Through The Use Of Overset Grids And Massively Parallel Computing, Douglas C. Blake Mar 1997

Advances In Time-Domain Electromagnetic Simulation Capabilities Through The Use Of Overset Grids And Massively Parallel Computing, Douglas C. Blake

Theses and Dissertations

A new methodology is presented for conducting numerical simulations of electromagnetic scattering and wave propagation phenomena. Technologies from several scientific disciplines, including computational fluid dynamics, computational electromagnetics, and parallel computing, are uniquely combined to form a simulation capability that is both versatile and practical. In the process of creating this capability, work is accomplished to conduct the first study designed to quantify the effects of domain decomposition on the performance of a class of explicit hyperbolic partial differential equations solvers; to develop a new method of partitioning computational domains comprised of overset grids; and to provide the first detailed assessment …

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A Comparison Of Circular Error Probable Estimators For Small Samples, Charles E. Williams Mar 1997

A Comparison Of Circular Error Probable Estimators For Small Samples, Charles E. Williams

Theses and Dissertations

Several previous studies investigated the performance of competing circular error probable (CEP) estimators for small samples. This estimation is important in ICBM analysis because, due to expense, there are a limited number of ICBM test launches. In the most recent previous study (1993), Tongue considered five CEP estimators in a simulation test, attempting to determine the behavior of these estimators for populations of various bias, ellipticity, correlation, and sample size. In this paper, we build on Tongue's findings in three ways: (1) The number of estimators compared is expanded to eight. (2) Different factors and factor levels are used. (3) …

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Analysis Of A Methodology For Linear Programming Optimality Analysis, Chanseok Jeong Mar 1997

Analysis Of A Methodology For Linear Programming Optimality Analysis, Chanseok Jeong

Theses and Dissertations

The methodology of Johnson, Baner, Moore, and Grant can be applied to large scale linear programming models. A methodology for optimality analysis of linear programs was developed to create metamodels using response surface methodology techniques such as experimental design and least squares regression. A metamodel consists of a simple equation which is able to predict the optimal objective function value of a linear program. What is needed is some large scale application of the techniques to verify how accurate they are. In the research, I plan to use the large scale LP model, STORM. I use the "Hot Start" idea …

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C-17/Paratrooper Risk Assessment Analysis, Jose C. Belano Mar 1997

C-17/Paratrooper Risk Assessment Analysis, Jose C. Belano

Theses and Dissertations

The C-17 test and evaluation community has been testing different aircraft formation geometries in search of a configuration which minimizes paratrooper encounter with the wake vortices of upstream aircraft. This thesis develops a simulation tool that the C-17 test and evaluation community can utilize as an advanced risk assessment model to use on proposed formation geometries prior to live testing. The model is developed under the architecture of object-oriented simulation using MODSIM III and parallels similar efforts by the Aerodynamic Decelerator Technology community in creating object-oriented counterparts to already developed trajectory models of various degrees of freedom. This thesis develops …

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Robust Parameter Estimation For The Mixed Weibull (Seven Parameter) Including The Method Of Minimum Likelihood And The Method Of Minimum Distance, Donald A. Mumford Mar 1997

Robust Parameter Estimation For The Mixed Weibull (Seven Parameter) Including The Method Of Minimum Likelihood And The Method Of Minimum Distance, Donald A. Mumford

Theses and Dissertations

Robust parameter estimation is successfully applied to the Mixed Weibull (seven parameter) using the Method of Minimum Distance and the Method of Maximum Likelihood. That is, parameters can now be estimated for a mixture of two Weibull distributions where the true populations are co-located, partially co-located or highly separated. Both techniques provided very robust estimates that were far superior to current parameter estimation techniques. Sample sizes as low as ten with mixing proportions down to 0.1 were investigated. For the MLEs, innovative bounding techniques are presented to allow consistent and correct convergence using any reasonable point estimate. The likelihood function …

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Net-Centric Design And Analysis Of Information Systems, Timothy R. Schmoyer Mar 1997

Net-Centric Design And Analysis Of Information Systems, Timothy R. Schmoyer

Theses and Dissertations

This thesis presents a unique methodology merging state of the art Internet and distributed database technology to support distributed simulations with programming language and platform independence. Standardized models of Command, Control, Communications, Computers, and Intelligence (C4I) systems using Integrated Definition (IDEF) models and executable simulation objects are placed in database repositories which can be accessed and implemented over a distributed simulation network using the Common Object Request Broker Architecture (CORBA). The CORBA distributed simulation network accesses heterogeneous distributed databases, performs distributed processes, and supports portability and reuse of simulation objects and interoperability across operating systems and programming languages.

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An Examination Of The Hanson Contrail Forecast Algorithm Under Low Relative Humidity Conditions, Robert P. Asbury Iii Mar 1997

An Examination Of The Hanson Contrail Forecast Algorithm Under Low Relative Humidity Conditions, Robert P. Asbury Iii

Theses and Dissertations

Accurate forecasts of contrail occurrence are essential to military aircrews. Although classical forecast methods have been reasonably successful predicting contrails, there is need for improvement at low ambient relative humidity. This thesis examines the performance of the Hanson method, which was developed to provide better contrail forecasts under drier atmospheric conditions. As a secondary objective, the forecast methods of Schumann and Hanson are compared to the algorithm currently in use by the Air Force Global Weather Central. Data used to validate the algorithms were collected at Wright-Patterson AFB, OH and Edwards AFB, CA. Theoretical contrail forecasts were made for each …

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A Validation Study Of The Ssm/I Temperature Algorithm And Comparison With The Cal/Val Land Surface Temperatures, Ronald L. Comoglio Mar 1997

A Validation Study Of The Ssm/I Temperature Algorithm And Comparison With The Cal/Val Land Surface Temperatures, Ronald L. Comoglio

Theses and Dissertations

The USAF operational cloud model, the Real-Time Nephanalysis (RTNEPH), requires infrared and visual scene scans as well as input from the Special Sensor Microwave Imager (SSM/I), featured on the Defense Meteorological Satellite Program (DMSP) polar orbiters. Additionally, SSM/I provides input to the Air Force Global Weather Center (AFGWC) surface temperature model (SFCTMP). The global surface temperatures are required for identifying which pixel of a scene is cloud and which is ground and as a first guess input to initialize NWP models. The SSM/I provides brightness temperatures sampled at four discrete: frequencies and dual polarizations to produce surface temperatures. Two algorithms …

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An Atmospheric Sensitivity And Validation Study Of The Variable Terrain Radio Parabolic Equation Model (Vtrpe), Matthew K. Doggett Mar 1997

An Atmospheric Sensitivity And Validation Study Of The Variable Terrain Radio Parabolic Equation Model (Vtrpe), Matthew K. Doggett

Theses and Dissertations

The Variable Terrain Radio Parabolic Equation (VTRPE) computer model is a powerful and flexible program that provides calculations of the radar propagation conditions of the atmosphere. It is limited however, by the accuracy and resolution of the input data. This study quantifies the sensitivity of the VTRPE model to the accuracy and resolution of the atmospheric parameters that go into it. Also, two case studies are examined to test the utility of VTRPE in operational use. The sensitivity to measurements of pressure, temperature, and humidity was found to be dependent on the meteorological environment. In standard and subrefractive environments, average …

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Optimization Of The Velocity Azimuth Display (Vad) Algorithm's Adaptable Parameters In The Wsr-88d System, Donald R. Farris Mar 1997

Optimization Of The Velocity Azimuth Display (Vad) Algorithm's Adaptable Parameters In The Wsr-88d System, Donald R. Farris

Theses and Dissertations

Meteorologists have encountered problems with the Velocity Azimuth Display (VAD) algorithm in the Weather Surveillance Radar - 1988 Doppler (WSR-88D) System. Under certain meteorological conditions, forecasters have observed differences between the radar's wind profiles and wind profiles from rawinsonde upper-air soundings, or wind profilers. One of the main causes of this problem is inversions in the atmosphere which cause the radar beam to subrefract or superefract, causing the VAD winds to be inaccurately reported at a particular height. This thesis used the WSR-88D Algorithm Testing and Display System (WATADS) to compare VAD winds from recorded Level 2 NEXRAD data at …

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Adaption Of The Air Weather Service Fog Model To Forecast Radiation Fog Events In The Southeast United States, Andrew C. Goodnite Mar 1997

Adaption Of The Air Weather Service Fog Model To Forecast Radiation Fog Events In The Southeast United States, Andrew C. Goodnite

Theses and Dissertations

This research examined the performance of the Air Weather Service (AWS) Fog Model and the potential for using it in the Southeast United States for predicting fog. This task was accomplished in four separate steps. First, a correlation study was performed by comparing different weather elements in observations that met radiational cooling conditions to the observed visibility. This correlation study showed that the 22 UTC dewpoint depression was correlated (0.60) with early morning fog and no other weather elements that are commonly observed had significant correlation with early morning fog. Second, a verification study was conducted on the Saint Louis …

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Validation Of The Air Force Global Weather Center Relocatable Window Model Total Cloud Forecast, Edward C. Harris Mar 1997

Validation Of The Air Force Global Weather Center Relocatable Window Model Total Cloud Forecast, Edward C. Harris

Theses and Dissertations

Air Force Global Weather Center's (AFGWC) Relocatable Window Model (RWM) total cloud forecasts were validated using data for selected days in May, June, and July, 1996. Forecasts were generated twice daily (00 UTC and 12 UTC) to determine the RWM's ability to accurately forecast total cloud cover during the late spring and early summer. The RWM forecasts were post-processed using the Slingo cloud forecast algorithm and compared against AFGWC's operational real time nephanalysis (RTNEPH) cloud analysis model. As a minimal-skill baseline comparison to the RWM's total cloud forecast, the RTNEPH initial analysis hour was persisted and evaluated against the same …

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Quantification Of Weather Effects On Imaging Laser Radar, Clifton D. Stargardt Mar 1997

Quantification Of Weather Effects On Imaging Laser Radar, Clifton D. Stargardt

Theses and Dissertations

The Air Force is investigating the use of imaging laser radar systems as autonomous guidance systems on future precision guided munitions. The Air Force's Wright Laboratory is currently testing a 1.06 micron wavelength laser radar (ladar) at Eglin Air Force Base. Since laser radiation can be susceptible to propagation problems through weather, quantitative understanding of these effects is important to the development of this weapon system. Ladar image degradation, in the form of target dropouts and false returns, was evaluated in various weather conditions. Statistical analysis of the images presented expected degrees of degradation according to visibility and rain fall …

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Ranking And Generating Alternatives For The National Air Intelligence Center's (Naic) Resource Allocation Strategy, Steven M. Cox Mar 1997

Ranking And Generating Alternatives For The National Air Intelligence Center's (Naic) Resource Allocation Strategy, Steven M. Cox

Theses and Dissertations

Allocating resources is never an easy task, especially when requirements call for more resources than those available. It gets more difficult when the availability of resources shrinks from year to year. This is the case at the National Air Intelligence Center (NAIC). In each of the past five years, NAIC has been forced to make their resource allocation decision with fewer dollars and less manpower. This decision has been time consuming, manpower intensive, and sometimes very heated. In an effort to lessen these three consequences, a resource allocation model, based upon the NAIC Commander's values and preferences, was developed. The …

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Modeling A Chemical Battlefield And The Resulting Effects In A Theater-Level Combat Model, Todd M. Gesling Mar 1997

Modeling A Chemical Battlefield And The Resulting Effects In A Theater-Level Combat Model, Todd M. Gesling

Theses and Dissertations

This thesis describes the development of a methodology to model chemical weapons use in the Joint Staff's Joint Warfare Analysis Experimental Prototype (JWAEP) and to quantify the resulting effects. The methodology incorporates organic unit assets and theater-level chemical assets into JWAEP by using the three principles of nuclear, biological, and chemical defense (NBC) which reflect joint and Army doctrine, and combines them with the basic concepts already used in existing theater-level models. Other aspects of the problem include representing chemical 'packages' on the battlefield, determining attrition and time effects, adjusting unit effectiveness, determining chemical package intelligence acquisition procedures, identifying solution …

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