Engineering Commons^™

Cost Constrained Improvements To The Military Retirement System, Cynthia A. Brown

Theses and Dissertations

This research studies possible changes to the current military retirement system. The current military retirement system refers to the system provided under the Military Reform Act of 1986, A new system is proposed which would provide the retiree with four options. Option 1 would provide a pay annuity and medical benefits to the retiree (this is the current system). Option 2 would provide a pay lump sum in place of the, annuity and would offer medical benefits. Option 3 would offer the pay annuity but give a medical lump sum amount in place of the medical benefit. Finally, option 4 …

Modified Anderson-Darling And Cramer-Von Mises Goodness-Of-Fit Tests For The Normal Distribution, David A. Gwinn Sr.

Theses and Dissertations

New techniques for calculating goodness-of-fit statistics for normal distributions with parameters estimated from the sample are investigated. Samples are generated for a Normal(0,1) distribution. Critical values are calculated for five modifications to the Anderson-Darling statistic and five modifications to the Cramer-Von Mises statistic. An extensive power study is done to test the power of the new statistics versus the power of the unmodified statistics. Powers of six of the new statistics show minimal to no improvement, two of the new statistics show a marked decrease in power, and two of the new statistics show an overall increase in power over …

Predicting The Productive Capacity Of Air Force Aerospace Ground Equipment Personnel Using Aptitude And Experience Measures, Robert S. Faneuff

Theses and Dissertations

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 Vocational Aptitude Battery (ASVAB). A second-order logistic model was used to regress PC on aptitude and experience at the task level and at the overall job, or aggregate, level. Model …

Construction And Testing Of A Neutron And Gamma Spectrometry System Using Pulse Shape Discrimination With An Organic Scintillator, Robert S. Pope

Theses and Dissertations

The goal of this thesis was to construct and test a neutron detector to measure the energy spectrum of 1 to 14-MeV neutrons in the presence of gammas. A spectrometer based on the process of pulse shape discrimination (PSD) was constructed, in which the scintillator NE-213 was used. The primary neutron/ gamma sources used were 78-mCi and 4.7-Ci ²³⁹PuBe sources, while 4.7-µCi and 97.6-µCi ²²Na gamma sources were used for energy calibration and additional testing of the detector. Proton recoil spectra and Compton electron spectra were unfolded with the neutron and gamma unfolding code FORIST to generate the …

A Monte Carlo Study Of The Raw And Normal Varimax Rotation Criterion In Factor Analysis, Willam M. Ibinson

Theses and Dissertations

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 multiplying each factor pattern by its transpose to create a covariance matrix. Data sets of multivariate normal deviates were in turn generated from each covariance matrix via the Choleski algorithm. …

Enhancements To The Animated Tutor For Air Combat Simulation, David A. Legge

Theses and Dissertations

This study investigates the use of the Ada programming language in combat modeling. It takes an existing combat model, the Animated Tutor for Air Combat Simulation (ATACS), and re-writes it into Ada. The new model also includes enhancements to the original model. ATACS+, as it is now called, is used as a learning tool in combat modeling classes at the Air Force Institute of Technology. ATACS+ consists of a preprocessor and a model, complete with two and three-dimensional graphics and engagement status reports. Conclusion are made about Ada's suitability for combat modeling, some of the features of Ada which can …

Analysis Of Topaz Ii And Space-R Space Nuclear Power Plants Using A Modified Thermionic Model, Otto D. Habedank

Theses and Dissertations

Models based on the TDS thermionic diode model were developed for TOPAZ II and SPACER nuclear power systems. Several parameter studies were conducted with the TOPAZ II model. These determined system performance and efficiency while varying the following: (1) Coolant flow inlet temperatures. (2) Rate of coolant temperature change. (3) Power profile of the core. (4) Cesium reservoir temperature. Analysis of results indicate the model accurately represented the TOPAZ II system, underestimating published data by 10%. Coolant flow studies indicate that raising coolant temperatures up to 100 K higher increases system power by up to 5%. Additional increases in temperature …

A Comparison Of Variable Selection Criteria For Multiple Linear Regression: A Second Simulation Study, David P. Woollard

Theses and Dissertations

This thesis implements a variable selection method proposed by Alan J. Miller, and makes an extension of Ross J. Hansen's 1988 thesis research by comparing the methods he examined: Minimum MSE, Minimum Sp, and Minimum Cp with Miller's method. Response Surface methodology is employed with two performance measures: the percentage of correct variables in a model and the Theoretical Mean Squared Error of Prediction (TMSEP). Each technique is applied on generated data with known multicollinearities, variances, random predictors, and sample sizes. Both performance measures are computed for models selected under each technique. A full factorial design using each performance measure …

Scheduling Air Mobility Command's Channel Cargo Missions, Gregory S. Rau

Theses and Dissertations

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 two-step process for revising AMC's channel mission schedule, this research can be used to improve the current schedule based on Step One's cargo flow. By carefully defining the notation and …

Theater Airlifter Survivability On The Ground, Michael A. Silver

Theses and Dissertations

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 by infantry weapons. A weapon is examined at each of several firing ranges to target. The threat to the aircraft is measured as the probability that the aircraft is hit. …

The Use Of Simulation To Evaluate Strategic Aeromedical Evacuation Policy And Planning, Charles W. Wolfe Jr.

Theses and Dissertations

Strategic aeromedical evacuation (AE) of casualties from the theater of operations to the CONUS during wartime is a complex operation that involves the integration of medical personnel and policies with airlift concepts and capabilities. Military analysts within the Air Mobility Command Analysis Group (AMC/XPY) have traditionally used deterministic linear programming techniques to estimate the number of aircraft the United States Air Force (USAF) requires for given contingency scenarios. However, this group has yet to develop a stochastic approach to validate their resource recommendations, and more importantly, to study the interrelationships between key factors comprising strategic aeromedical evacuation. As the possibility …

A Modified Chi-Squared Goodness-Of-Fit Test For The Three-Parameter Gamma Distribution With Unknown Parameters, Thomas J. Sterle

Theses and Dissertations

A modified chi-squared goodness-of-fit test was created for the gamma distribution in the case where all three parameters must be estimated from the sample. Critical values are generated using a Monte Carlo simulation procedure with 5000 repetitions each. Random samples of 8 different sizes were drawn from gamma distributions with shape parameters 1, 1.5, 2., and 2.5. The shape, scale, and location parameters were then estimated from each sample, using an iterative technique combining the maximum likelihood and minimum distance methods, enabling, computation of the chi-squared statistics and critical values. The same process is used to generate random samples, parameter …

Using Animation In The Validation Of Simulation Models, Michael L. Carpenter

Theses and Dissertations

This study examined three aspects of animation (movement, color, and detail of icons) to determine which one (or ones) best communicated the operation of a simulation model. The procedure was done in the context of using animation to establish a model's face validity. Movement, color, and detail of icons were looked at individually and in combination. The ability to communicate was measured both subjectively and objectively. The subjective measures were a selection of best and worst animation types where best and worst referred to how well an animation communicated, and a pairwise comparison of the animation types which resulted in …

Optimal Silo Attack Plan For The Red Integrated Strategic Offensive Plan (Risop), Richard C. Pace

Theses and Dissertations

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 both the flight time of the missile that impacts first and the duration of the attack. J- 8 defined several input rules which limit how missiles may be allocated. A …

A Modified Anderson Darling Goodness-Of-Fit Test For The Gamma Distribution With Unknown Scale And Location Parameters, Tamer Ozmen

Theses and Dissertations

A new modified Anderson-Darling goodness-of-fit test is introduced for the three-parameter Gamma distribution when the location parameter is found by minimum distance estimation and scale parameter by maximum likelihood estimation. Monte Carlo simulation studies were performed to calculate the critical values for A-D test when A-D statistic is minimized. These critical values are then used for testing whether a set of observations follows a Gamma distribution when the scale and location parameters axe unspecified and are estimated from the sample. Functional relationship between the critical values of A-D is also examined for each shape parameter by the variables, sample size …

The Airlift Capabilities Estimation Prototype: A Case Study In Model Validation, Randy Mccanne

Theses and Dissertations

This study investigates the application of a life cycle approach to the validation of operational models. The classic waterfall life cycle from software engineering is adapted for use on mathematical models by defining four stages of model development. Each stage is discussed in detail and examples of the output from each stage are presented. In addition, techniques are investigated for applying the proposed life cycle to existing models through the recovery of life cycle stages. The methodology is applied to a linear programming model developed for planning airlift operations to demonstrate the power of the life cycle approach to validation. …

Bradley Fighting Vehicle Gunnery: An Analysis Of Engagement Strategies For The M242 25-Mm Automatic Gun, James G. Riley

Theses and Dissertations

This thesis studies various engagement strategies for the Bradley Fighting Vehicle's 25-mm automatic gun firing APDS-T ammunition against a BMP- type target. The Army currently provides only the broadest guidance for the structure of the 25-mm point target engagement which results in the employment of an assortment of strategies throughout the Bradley community. The goal of this research was to determine if a best method exists. Bradley gunnery is a complex set commander/gunner interactions which can be difficult to represent with the analytic models commonly found in the literature. A model, based on the simulation methods used by the US …

Determining Cargo Flow For Air Mobility Command's Channel Cargo System, Michael Del Rosario

Theses and Dissertations

This research investigated using a multiperiod multicommodity minimal cost flow (M2MCF) formulation to model the channel cargo system of the United States Air Force's Air Mobility Command (AMC). The objective of this research was to determine how cargo should flow in the channel cargo system in order to minimize the cargo's delay enroute from its origin to its destination. This research showed the size of an M2MCF model of the channel cargo system exceeds AMC's computational capabilities. Additionally, this research describes three approaches to reduce the problem size. Because of the problem size and other modeling limitations discovered during this …

Integrating Psychological Operations Into The Joint Theater Level Simulation (Jtls), C. Matthew Pecot Iii

Theses and Dissertations

This thesis provides a prototype and methodology for integrating psychological operations (PSYOP) into the Joint Theater Level Simulation (JTLS) combat model. The requirement rose out of the need for aggregate-level training models to reflect the role of PSYOP so that commanders and their staffs can learn how to manage plan for, and conduct PSYOP within the context of AirLand battle doctrine. As the JTLS model currently exists, there is no representation of psychological operations whatsoever. This thesis outlines a methodology for incorporating the PSYOP analysis process (including the target audience analysis), the PSYOP product development and production process, the PSYOP …

An Analysis Of The Generalized Lambda Distribution, Robert J. Bergevin

Theses and Dissertations

The Generalized Lambda Distribution (GLD) is a four parameter function that is capable of mimicking the behavior of a wide range of probability density functions (pdfs). Unfortunately, the GLD presently cannot model every possible type of pdf. Since the reasons for this limitation are unknown, this thesis examines several potential problems in an attempt to expand the range of distributions the GLD can mimic. We first present a discussion of the behavior of the algorithm that is used to search for the appropriate GLD parameter values. In particular, we examine the effect of using an unconstrained search to find the …

A New Goodness-Of-Fit Test For The Weibull Distribution Based On Spacings, Mark C. Coppa

Theses and Dissertations

The critical values for a new goodness-of-fit test based on spacings are generated for the Weibull distribution when the shape parameter is known. The critical values are used for testing whether a set of observations follow a Weibull distribution when the scale and location parameters are unknown. A Monte Carlo simulation with 10,000 iterations is used to generate the critical values for sample sizes 5(5)35 at shape parameters k equal to 0.5(0.5)1.5 and for sample sizes 5(5)20 at shape parameters k = 2.0(1.0)4.0. A Monte Carlo power study of the Z* test statistic using 5000 iterations is accomplished using nine …

The Battle Of Little Round Top: An Analysis Of Battle Alternatives Through Commercial Wargames, John J. Mcguiness

Theses and Dissertations

This thesis examines the problem of whether one can use commercial wargames as a tool for historical research. The research examines two wargames dealing with the battle of Little Round Top: Gettysburg: The Turning Point and Thunder at the Crossroads. This research emphasized the need to analyze the wargame's structure prior to playing the game. This will avoid a possible mistake of drawing a conclusion about a particular driver in the battle which may not be from the historical situation but rather an inevitable outcome produced by the model's basic assumptions. Additionally, quantitative measures of time lines, casualty rates, and …

A Fuzzy Logic Optimal Control Law Solution To The Cmmca Tracking Problem, Randy E. Nelson

Theses and Dissertations

The Air Force uses the C-18 Cruise Missile Mission Control Aircraft (CMMCA) to radar track cruise missiles (CM) during test flights. Because of the complexity of the CM flight profiles, maintaining radar coverage at all times is very difficult. This thesis attempted to apply optimal control theory to construct a simulation providing 100% radar coverage. The simulation was divided into ten second intervals, and fuzzy logic was used at the start of each interval to determine the set point, i.e., that point in space where the CMMCA should be in ten seconds. The set point calculation's fuzzy logic balanced CMMCA …

Patient Scheduling And Aircraft Routing For Strategic Aeromedical Evacuation, Michael J. Loftus

Theses and Dissertations

The objective of this study is to develop an approach that would assign patients to aeromedical evacuation aircraft and route each aircraft to a single CONUS airport. The goal is to minimize total patient wait time. A heuristic algorithm is developed which exploits the structure of the problem. The first subproblem solved is the assignment of aircraft to airports. This subproblem is solved using integer programming and the results are input into the second subproblem. The second subproblem is the patient to aircraft assignment problem. This subproblem minimizes patient wait time and is solved using network flow programming. The two …

An Analysis Of Tactical Airlifter Characteristics And Their Impact On Theater Airlift System Performance, John J. Koger

Theses and Dissertations

This study used computer simulation and Response Surface Technology to determine what tactical airlifter characteristics most impact theater airlift system performance in a Southwest Asia (SWA) scenario. Some Aircraft characteristics were grouped into functional sets, while others were considered individually. After screening one characteristic, reliability, with a two-level factorial experiment, a Box-Behnken design was used to estimate second-order metamodels. A stepwise regression procedure indicated that, if attrition rates are ignored, airlift system performance is most impacted by the aircraft's size, survivability, cruise speed, and ability to operate on short fields. The SWA scenario used in this study covers a large …

Estimating Test Range Capacity, Paul A. Mcdaniel

Theses and Dissertations

The main focus of this thesis effort was to develop a means to estimate the capacity of the test range complex at Eglin AFB, Florida. For the purposes of this study, test range capacity was defined as the maximum number of missions, of a given set, that could possibly be supported by range resources on any given day. In trying to determine this number, the complexities of the overall multi-resource constrained scheduling problem dictated a more practical approach be taken in modeling the allocation process of range resources to test missions. Therefore, a series of three single-resource, 0-1 integer programming …

Assessment Of 1991 Nehrp Provisions For Nonstructural Components And Recommended Revisions, Tsuteh Soong, Genda Chen, Z. Wu, R. H. Zhang, M. Grigoriu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As one part of the 1994 update effort of the 1991 NEHRP provisions, the seismic design force formulas for nonstructural components as they exist in the 1991 provisions are critically assessed and some of their shortcomings are identified. Various levels of improvements to these formulas are then presented which, on the one hand, preserve the equivalent lateral force format for design applicability and, on the other, correct some of the deficiencies on the basis of analyses, experimental results and observation data from past earthquakes.

Based on different interpretations of the component seismic coefficients as well as different degrees of simplicity …

Evaluation Of Diamond Grade Reflective Sheeting, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this project was to monitor the performance of the diamond grade sheeting when used on both typical traffic signs and construction signs. The durability, appearance, and reflectivity of the signs were monitored. Diamond grade sheetings used on typical traffic signs were evaluated over a two-year period with construction signs evaluated over an 18-month period.

Diamond grade sheeting was found to provide increased reflectivity compared to high intensity sheeting with no problems noted related to durability or appearance. However, the cost of the diamond grade sheeting would limit its use to situations where brighter, wider-angle reflective sheeting is …

Field Performance Evaluation Of Precast Concrete Box Culverts, Aluminum Culverts, And Galvanized Metal Arches And Pipe Arches, L. John Fleckenstein, David L. Allen, R. Clark Graves

Kentucky Transportation Center Research Report

Reported herein are the field performances of three different classes of culverts. The study included precast concrete boxes, precast arch culvert, aluminum boxes and pipe culverts, and several shapes of galvanized metal culverts. A total of 82 culverts were inspected throughout the state of Kentucky. Culverts were inspected in all 12 highway districts. A total of 15 precast concrete structures, 11 aluminum structures, and 56 galvanized metal structures were evaluated. This report discusses the distress observed in the three different classes of culverts and recommendations for future installations and possible maintenance schema for the existing culverts are included.

Pavement Drainage And Pavement-Shoulder Joint Evaluation And Rehabilitation, Zubair Ahmed, Thomas D. White, Philippe L. Bourdeau

JTRP Technical Reports

The objectives of this research were i) to evaluate the performance of pavement subdrainage systems ii) study the behavior of moisture conditions below pavements and iii) provide recommendations for unproved drainage criteria based on analysis of field data. Existing and retrofitted subdrainage collector systems were inspected through external visual inspection in combination with a probe for internal inspection. Distresses and deficiencies in construction observed were listed and compiled on video. A methodology for inspection is presented that can be used by highway agencies in monitoring the condition, need for maintenance, and performance of collector systems. Pavements with various types of …