Digital Commons Network^™

Developing A Template For Logistics Test And Evaluation, Timothy J. Fennell, Jason S. Mogle

Theses and Dissertations

Logistics test and evaluation, performed during the developmental test and evaluation effort, is an integral part of the aircraft acquisition process. However, there has been no standard approach to conducting logistics test and evaluation. This study researched past and present approaches to aircraft logistics test and evaluation to determine the most effective method for future programs. We conducted this study using the Delphi method. We solicited the expert opinions of 32 individuals from the logistics test and evaluation field using two rounds of questions. We then statistically analyzed the data to ultimately develop a logistics test and evaluation template. We …

Benchmarking Customer Service Practices Of Air Cargo Carriers: A Case Study Approach, Patrick D. Lozon, Michael B. Mcdaniel

Theses and Dissertations

This study used the benchmarking process incorporated in a case study approach to determine what the Air Force could learn from the commercial air cargo carriers in regard to customer service practices. The air cargo industry leaders were determined through a previous study to be United Parcel Service, Federal Express, Emery Air Freight, Airborne Freight, DHL Airways, and Burlington Air Express. In addition, the 437th Aerial Port Squadron APS at Charleston AFB South Carolina was the Air Force representative in the benchmarking study. Interviews with air cargo managers were conducted at each carrier’s main hub and at Charleston AFB. The …

Logistics Control Facility: A Normative Model For Total Asset Visibility In The Air Force Logistics System, Eric C. Lorraine, Michael E. Michno

Theses and Dissertations

Computer simulation was used to evaluate the impact of a Logistics Control Facility LCF with a Total Asset Visibility TAV system on the AF logistics systems ability to support a weapon system. For this study, the B-1B was chosen as the weapon system of interest. Two performance measures, expected fully mission capable rates and expected pipeline quantities, were used to evaluate the simulation results. Two-sample tests were used to compare the current logistics configuration of the B-1B with the same configuration, but with an LCF controlling the movement of assets. The expected FMC rate performance measure showed significant results while …

Analysis Of The Jplan Exercise As An Experimental Learning Tool, Mark J. Lynch, Michael E. Washington

Theses and Dissertations

The purpose of this study is to develop an effective educational tool for the Combat Logistics course offered at the Air Force Institute of Technology. The current tool being used, the JPLAN Exercise, was identified as outdated in several areas. The research focused upon four investigative questions what makes an effective educational tool, should the existing exercise be revised or replaced, which logistics principles are essential for incorporation into the educational tool, and is the updated tool significantly different from the original. To answer these questions, we conducted an extensive literature review that focused on two areas. The first area …

How Effective Has The Air Force Been In Eliminating Its Dependence On Ozone Depleting Chemicals?, L. Susan Willard

Theses and Dissertations

This research was undertaken to determine how effectively the Air Force had eliminated its dependence on Ozone Depleting Chemicals. The research was limited to analyzing the impact of ODCs on major acquisition programs. Results indicated existing variables which may be impeding full implementation. Also identified were lessons learned which could be applied to future environmental legislation with potential impact on acquisition programs. In- depth telephonic interviews were conducted with Program Directors responsible for the development and fielding of major Air Force acquisition programs. Analysis revealed that ODCs substantially impacted the acquisition programs to the extent that many programs had classified …

Organic Maintenance Performance Measurement: A New Approach, John S. Nehr, William G. Queener

Theses and Dissertations

The growing role of Air Force Air Logistics Centers ALC in complex, multiyear developmental programs increases the need for effective cost and schedule performance measurement. In order to effectively manage these activities, timely and accurate cost and schedule information must be collected and compared with an established baseline. The ALCs need a new management technique which facilitates this type of performance measurement. A proven approach to cost and schedule performance measurement in weapon system acquisitions is Earned Value EV. This approach, required of contractors who are subjected to the CostSchedule Control Systems Criteria CSCSC, allows the program manager to obtain …

A Maintenance Manpower Study Of The Composite Wing At Mountain Home Afb, Stella T. Smith, Cristina C. Vilella

Theses and Dissertations

In response to changes in threats, the Air Force has reorganized several flying units into composite wings. They are intended to provide a flexible, rapid deployment force. This study focused on the impact of the composite wing organizational structure on the determination of maintenance manpower authorizations at Mountain Home AFB, the Air Forces first air intervention wing. An opinion survey of maintenance and manpower experts was used to identify factors that are important in the determination of maintenance manpower authorization levels. Statistical analysis identified important-factors and indicated differences in opinion between maintenance and manpower specialists. Factors specific to the composite …

An Analysis Of Alternative Methods Of Measuring Hazardous Waste Reduction Progress At The Air Force Materiel Command's Air Logistic Centers, Edward C. Finke

Theses and Dissertations

his study investigated the relationship between aircraft related maintenance activity and the amount of hazardous waste (HW) disposed of by Air Force Materiel Command's (AFMC) Air Logistic Centers (ALC). These ALCS, along with the Aircraft Guidance and Meteorology Center, generate approximately 76 percent of the HW generated by the Air Force. The activity indexing and least squares curve fitting methods were used to predict the amount of HW that would have been disposed of based on the relative level of aircraft related maintenance activity had no pollution prevention efforts been implemented. These predictions were then compared to what historically occurred …

Development Of An Analytical Hierarchy Process (Ahp) Model For Siting Of Municipal Solid Waste Facilities, Dimasalang F. Junio

Theses and Dissertations

Deciding on locations for municipal solid waste facilities is a difficult problem where qualitative criteria compete with quantitative economic and engineering criteria, in an environment that is highly political and emotional. State guidelines often describe different methodologies but fall short in offering a solution or a methodology in arriving at a solution. This study develops a decision modeling procedure, based on the Analytical Hierarchy Process (AHP), that can be used by public sector decision makers to locate and site municipal solid waste facilities. The applicability of the procedure is demonstrated at the City of Springfield, Clark County, Ohio. Research efforts …

Optimal Utilization Of Field Generated Analytical Data For Site Characterization And Remedial Decision Making, Ronald J. Lester

Theses and Dissertations

This study developed data quality standards for assessing environmental analytical data quality and its use in remedial decision making, specifically in risk assessment calculations. The primary purpose was to increase the use of field generated data in environmental site investigations versus the continued reliance on costly and time consuming EPA Contract Lab Program data. Increased reliance on field lab data could significantly reduce remedial investigation costs. The standards developed are based on regulatory criteria for data useability, achievable quality in a CLP lab setting, and basic statistical methods. The standards were applied to sets of Volatile Organic Compound data in …

Economics Of Chlorofluorocarbon (Cfc) Machine Replacement, Geoffrey D. Rudderow

Theses and Dissertations

Continued use of chlorofluorocarbon CFC refrigerants may have a severe financial as well as operational impact on the users of air-conditioning and other refrigeration equipment as price increases continue and production is phased out. With production of CFCs coming to a halt on 31 December 1995, the two major refrigerants that have been used in commercial and industrial cooling applications will no longer be available. The phase out of production is a result of national and international agreement that these, as well as other CFCs, are a primary cause of the depletion of the stratospheric ozone layer. To help the …

Evaluation Of Alternative Methods For Wastewater Disinfection, David C. Piech

Theses and Dissertations

This study investigated the alternative methods of wastewater disinfection. Areas of interest included methods of operation, ease of maintenance, and effectiveness for various types of wastewater. A literature search revealed three major disinfection options, which include chlorination dechlorination, ultraviolet light, and ozone. A questionnaire was sent to the active duty Air Force installations that operate wastewater treatment plants, requesting permit limitations and monthly averages for a variety of wastewater parameters. The majority of Air Force wastewater treatment plants use chlorine for disinfection. Using the data obtained from the questionnaire responses and established wastewater parameters from other research, the basic design …

Polynomial Real Root Finding In Bernstein Form, Melvin R. Spencer

Theses and Dissertations

This dissertation addresses the problem of approximating, in floating-point arithmetic, all real roots (simple, clustered, and multiple) over the unit interval of polynomials in Bernstein form with real coefficients.

Modeling Of Ground Water Aquifer Remediation By Pulsed Pumping When Contaminant Transport Is Affected By Physical, Non-Equilibrium Sorption And Desorption, Jeffrey L. Caspers

Theses and Dissertations

This research postulates and demonstrates a modification incorporating rate-limited sorption effects in the USGS SUTRA code for cleanup of a hypothetical sandy aquifer by pump-and-treat remediation methods. Contaminant transport is assumed to be affected by advection, dispersion, and rate-limited sorption/desorption. Sorption is assumed to be either equilibrium or rate-limited, with the rate-limitation described by either a first-order law, or by Fickian diffusion of contaminant through a spherical immobile pore region. Solutions are arrived at by split operator methods for the transport and one-dimensional Galerkin solutions for the solute concentration equations. The resulting model is tested against an analytical Laplace transform …

Use Of Infrared Spectrometry To Determine The Effect Of Trichloroethylene Resident Time On Desorption Rates From Flint Clay, Peter T. Lapuma

Theses and Dissertations

This laboratory based thesis investigated the desorption rate of trichloroethylene (TCE) from flint clay while varying the resident time of TCE exposed to the clay. It is thought that in long contaminated soil, a majority of contaminant mass will become entrained within the interior of the soil particles to slowly desorb out of the soil over long periods of time. Recent studies suggest that the longer a contaminant is resident in soil, the longer the contaminant will take to desorb from the soil. To understand more about soil desorption, this experiment was developed using infrared spectroscopy to detect TCE vapor …

Numerical Simulation Of Dynamic-Stall Suppression By Tangential Blowing, Matthew C. Towne

Theses and Dissertations

The use of tangential blowing to suppress the dynamic stall of a pitching airfoil is investigated numerically. The laminar two-dimensional, compressible Navier-Stokes equations are solved time-accurately using a Beam- Warming algorithm. A slot is located at four different positions along the surface of a NACA 0015 airfoil and air is injected in a nearly tangential sense along the upper surface. Suction control is also employed at one of these slot locations to directly compare with tangential-blowing control. Solution sensitivity to grid refinement, time-step size, numerical smoothing, and initial conditions is investigated at a Reynolds number of 2.4 x 10exp 4. …

Embedded Chaotic Time Series: Applications In Prediction And Spatio-Temporal Classification, James R. Stright

Theses and Dissertations

The Deterministic Versus Stochastic algorithm developed by Martin Casdagli is modified to produce two new, methodologies, each of which selectively uses embedding space nearest neighbors. Neighbors which are considered prediction relevant are retained for local linear prediction, while those which are considered likely to represent noise are ignored. For many time series, it is shown possible to improve on local linear prediction with both of the new algorithms. Furthermore, the theory of embedology is applied to determine a length of test sequence sufficient for accurate classification of moving objects. Sequentially recorded feature vectors of a moving object form a training …

The Excitation Mechanism Of Praseodymium-Doped Semiconductors, Paul L. Thee

Theses and Dissertations

This study on praseodymium Pr luminescence in Al_xGa_1-xAs was conducted to enhance the understanding of the excitation mechanism. Pr was implanted at 390 keV with doses from 5 x 10¹² to 5 x 10¹³ sq cm into Al_xGa_1-xAs x0.0 to 0.50 wafers which were annealed using the rapid thermal annealing RTA method. Low temperature photoluminescence PL was conducted using an Ar-ion laser and Ge detector. PL emissions of Pr from all hosts include peaks near 1.3 and 1.6 µm which are assigned to the intra-4f transitions of 1G4 yielding 3H5 …

Computational Investigation Of An Improved Cowl Concept For Hypersonic Propulsive Nozzles, Mark C. Butler

Theses and Dissertations

The effects of placing a gas generator into the cowl of a hypersonic nozzle/afterbody were investigated computationally. Gas generator mass flow and deflection angle effects were analyzed for two nozzle/cowl geometries; an experimentally validated nozzle/cowl configuration evaluated at off-design conditions and a generic hypersonic propulsive nozzle evaluated at more realistic on design conditions. A combination of Van Leer flux-vector splitting and Roe flux-difference splitting finite volume computational algorithms were used to solve the unsteady two-dimensional Navier-Stokes equations based on planar, laminar flow, perfect gas equation of state assumptions. For the low speed off-design cases analyzed, gas generator effects on nozzle …

Mixed H2-H∞ Optimization With Multiple H Infinity Constraints, Julio C. Ullauri

Theses and Dissertations

A general mixed H₂/H_∞ optimal control design with multiple H_∞ constraints is developed and applied to two systems, one SISO and the other MIMO. The SISO design model is normal acceleration command following for the F- 16. This design constitutes the validation for the numerical method, for which boundaries between the H₂ design and the H_∞ constraints arc shown. The MIMO design consists of a longitudinal aircraft plant (short period and phugoid modes) with stable weights on the H₂ and H_∞ transfer functions, and is linear- time-invariant. The controller order is reduced …

Design And Analysis Of A Mode B And Mode Jd Satellite Earth Station, Dennis J. Hance

Theses and Dissertations

This thesis focuses on the design, integration, and analysis of an amateur radio service mode B and mode JD satellite earth station. Preliminary designs were investigated to determine the optimum configuration for the earth station. Modern digital modems, cabling structures, an 80386-based computer system, satellite tracking software, transmission and reception antennas, preamplifiers, and sophisticated performance measurement technologies were integrated into a functioning earth station. Initially, component availability and station design dictated the selection and acquisition of the requisite station equipment, integration of the transmitter, receiver preamplifiers, antennas, and computer equipment followed. Preliminary testing of the various components in the integration …

The Application Of Nepa Requirements To Cercla Remedial Actions, Connie L. Strobbe

Theses and Dissertations

This study investigated the application of National Environmental Policy Act NEPA requirements to Comprehensive Environmental Response, Compensation, and Liability Act CERCLA actions. Similarities in the documentation and public participation requirements of NEPA and CERCLA include identification and evaluation of alternatives and public participation. Differences include document contents and timing of public participation. This study presented four options for ensuring NEPA compliance at CERCLA sites. Option one included a Programmatic Environmental Impact Statement PEIS with subsequent combined FSEIS report for each subunit. Option two eliminated the PEIS, but retained a stand-alone NEPA document for each CERCLA subunit. Option three included a …

H2 Optimal Control With H∞, Μ, And L1 Constraints, David E. Walker

Theses and Dissertations

H₂ optimization with convex constraints is considered. The optimal order-free solution is shown to be unique through convex analysis. H_∞ constraints with feedforward terms and singular constraints are also allowed. The optimal fixed-order solution is shown to have the same characteristics as a mixed problem with regular H_∞ constraints. Furthermore, these results are shown to hold for controller orders as low as the optimal H₂ order. A numerical method is developed based on analytical gradients which results in sub- and super-optimal fixed-order controllers. The problem is extended to include an upper bound on a mu constraint …

Noise Reduction For Speech Enhancement Using Non-Linear Wavelet Processing, Hassan Dehmani

Theses and Dissertations

The problem of speech enhancement presents many obstacles in the speech processing field. This thesis develops several speech de-noising systems that can be used in the time, fourier, and wavelet domains. We present two thresholding techniques soft and hard. The application of these thresholding techniques to noisy speech data is discussed. The combination of both wavelets and the Fourier domains with noisy phase restoration proves to yield the best results in terms of intelligibility. Informal listening tests were conducted in order to compare the effects and differences between the speech de-noising systems.

Effects Of Thickness And Curvature On The Natural Frequencies Of Cylindrical Composite Shells, Jose L. Monteverde E.

Theses and Dissertations

An analytical study is performed to determine the dynamic response, natural frequencies and mode shapes, of deep composite cylindrical shells, including the effect of through the thickness shear strain. The DSHELL finite element program is used to predict the first four natural frequencies and the results are compared to a reference using the Galerkin technique. The program was extended to problems considering simply supported-free boundary conditions. As is well know, the free boundary is rather difficult to represent using the Galerkin technique approach. The mode shapes are created by plotting a surface-contour plot of the eigenvector output from DSHELL.

A …

Dynamic Load Balancing For A Parallel Discrete-Event Battlefield Simulation, Seth R. Guanu

Theses and Dissertations

This thesis investigates issues involved in developing a dynamic load balancing model for a parallel discrete event battlefield simulation. The research covers issues in task management, discrete-event simulation, parallel simulation, and load balancing. There are four primary issues discussed concerning the design of a dynamic load balancing model. The first issue is processor load evaluation which deals with the calculation of the amount of work on a processor. The second issue is load balancing profitability determination which deals with the decision to load balance or not based on some cost-gain relationship. The third issue is task migration which deals with …

Spatio-Temporal Pattern Recognition Using Hidden Markov Models, Kenneth H. Fielding

Theses and Dissertations

A new spatio-temporal method for identifying 3D objects found in 2D image sequences is presented. The Hidden Markov Model technique is used as a spatio-temporal classification algorithm to identify 3D objects by the temporal changes in observed shape features. A new information theoretic argument is developed that proves identifying objects based on image sequences can lead to higher classification accuracies than single look methods. A new distance measure is proposed that analyzes the performance of Hidden Markov Models in a multi-class pattern recognition problem. A three class problem identifying moving light display objects provides experimental verification of the sequence processing …

Calibration And Initial Testing Of A New Hydraulic Simulator, Cristian A. Puebla

Theses and Dissertations

In the present research, the flow field associated with the ejection of a crew capsule from the fuselage of a high speed generic aircraft was experimentally investigated by means of the modified gas hydraulic analogy. For this, an existing hydraulic simulator was calibrated and modified to adapt it to the needs of the experiment. The analogy was evaluated for a five-sided capsule alone, and good quantitative agreement with the 2-D shock-expansion theory was obtained. It was found that the size of the model played a key role in the determination of good quantitative data. The analysis of the capsule interacting …

A Diffraction-Based Model Of Anisoplanatism Effects In Adaptive Optic Systems, Steven E. Troxel

Theses and Dissertations

This dissertation presents a new model for computing the angle dependent performance measures of an adaptive-optics system. By incorporating diffraction caused by the index-of-refraction variations of the atmosphere, the phase and amplitude fluctuations of the propagating wave are computed. New theory is presented, that uses the diffraction-based propagation model to yield optical transfer function (OTF) expressions that are more accurate as compared to current theory that neglects diffraction. An evaluation method for calculating the OTF is presented that utilizes a layered atmospheric model and normalized OTF expressions. The diffraction model is also used to present the first OTF signal-to-noise ratio …

Multirate Time-Frequency Distributions, John R. O'Hair

Theses and Dissertations

Multirate systems, which find application in the design and analysis of filter banks, are demonstrated to also be useful as a computational paradigm. It is shown that any problem which can be expressed a set of vector-vector, matrix-vector or matrix-matrix operations can be recast using multirate. This means all of numerical linear algebra can be recast using multirate as the underlying computational paradigm. As a non-trivial example, the multirate computational paradigm is applied to the problem of Generalized Discrete Time- Frequency Distributions GDTFD to create a new family of fast algorithms. The first of this new class of distributions is …