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Design And Analysis Of Electrical Circuits That Produce Fractional-Order Differentiation, Richard N. Hughes
Design And Analysis Of Electrical Circuits That Produce Fractional-Order Differentiation, Richard N. Hughes
Theses and Dissertations
Two half-order differentiator circuit designs were investigated and their electrical performance evaluated (Oldham and Oldfield). Initially, each circuit design was computer modelled and simulated using the HSPICE computer analysis program. Then, each circuit design (Oldham and Oldfield) was fabricated with two different component technologies. This resulted in four circuits, realized on printed circuit boards, to be evaluated--Oldham discrete component; Oldham hybrid component; Oldfield discrete component; and Oldfield surface mount component. The characterizations of each circuit's electrical performance is documented with time, phase, gain, noise and spectrum responses. A comparison of each circuit's performance versus the design criteria and computer model …
Exponential Characteristic Spatial Quadrature For Discrete Ordinates Neutral Particle Transport In Slab Geometry, Glenn E. Sjoden
Exponential Characteristic Spatial Quadrature For Discrete Ordinates Neutral Particle Transport In Slab Geometry, Glenn E. Sjoden
Theses and Dissertations
A new discrete ordinates spatial quadrature scheme is presented for solving neutral particle transport problems. This new scheme, called the exponential characteristic method, is developed here in slab geometry with isotropic scattering. This method uses a characteristic integration of the Boltzmann transport equation with an exponential function as the assumed from of the source distribution, continuous across each spatial cell. The exponential source function is constructed to globally conserve zeroth and first spatial source moments and is non-negative. Characteristic integration ensures non- negative fluxes and flux moments. Numerical testing indicates that convergence of the exponential characteristic scheme is fourth order …
Design And Construction Of A Channel Electron Multiplier Based Mossbauer Spectroscopy System, Daniel J. Robbins
Design And Construction Of A Channel Electron Multiplier Based Mossbauer Spectroscopy System, Daniel J. Robbins
Theses and Dissertations
A channel electron multiplier (cem) detector system was designed and built to provide a signal to a Mossbauer spectroscopy system in an effort to obtain a better signal-to-noise ratio than achievable with a proportional counter system. Three cems are contained in a vacuum chamber built using standard components. Gamma, rays of 14.4-keV energy from a 57Co source enter from outside the chamber through a window and are absorbed by an 57Fe target near the cems. The target emits internal conversion electrons which are collected by the cems and a Mossbauer spectrometer collects the signal. The system produces a …
Multilayer Perceptrons For Classification, Lisa M. Belue
Multilayer Perceptrons For Classification, Lisa M. Belue
Theses and Dissertations
Techniques for training, testing, and validating multilayer perceptrons are thoroughly examined. Results obtained using perceptrons are compared and contrasted with two multivariate discriminant analysis techniques- logistic regression and k neighbor. Methods for determining significant input features are investigated and a procedure for examining the confidence to place in the significance of these features is developed. Procedures to evaluate the applicability of high-order feature inputs are examined. These methods and procedures are applied to two very different applications. The first application concerns the prediction of Air Force pilot retention/separation rates for input to force projection models. The second application concerns the …
An Analysis Of The Endurance Of Mobile Satellite Command And Control Systems, Steven O. Brown
An Analysis Of The Endurance Of Mobile Satellite Command And Control Systems, Steven O. Brown
Theses and Dissertations
This study investigated the endurance of a single deployed generic mobile space (GMS) command and control (C2) system. Specifically, factors which affect overall system performance were examined. The analysis began with the development of a simulation model for a GMS C2 system. Optimal settings of factor levels were determined by using the model to find peak system endurance and availability. Factors set were field support vehicle (FSV) access, numbers of maintenance personnel, and numbers of spare components available. After optimum values were chosen for these factors, an experimental design was conducted to determine factor effect between maintenance manpower and the …
Transformation Of Combat Data In Support Of Battle Trace, Hyoung-Kyu Choi
Transformation Of Combat Data In Support Of Battle Trace, Hyoung-Kyu Choi
Theses and Dissertations
The purpose of this study was to find an appropriate way of characterizing battle data as a function of time. This study was initially designed to remove the numerical instability problem cited in Barr's battle trace methodology as suggested by TRAC-MTRY. The research focused on the instability problem and identifying/recommending a technique that improved the efficiency of computation, and enhanced an analyst's ability to meaningfully interpret the battle trace. Two Lanchester's Square Law based methodologies are introduced and analyzed. The results of this analysis indicate that the battle trace of a constant value generated by Lanchester's Square Law integration seemed …
Visual Information Processing And Response Time In Traffic-Signal Cognition, Hasan H. Demirarslan
Visual Information Processing And Response Time In Traffic-Signal Cognition, Hasan H. Demirarslan
Theses and Dissertations
In man-machine design, it is important to quantify the reaction time components instead of simply determining the lump-sum reaction time to stimulus. The primary purpose of this thesis was to investigate the reaction time components, such as visual perception and muscle response time, and to quantify them by separating from their aggregated sum. The prime example, traffic-signal cognition simulation was used to examine human reaction time to signal change. With a modified computer program that stimulates the driver's approach to the intersection, we measured the subject's reaction times and examined behavioral patterns. Twelve subjects were involved in the experiment. A …
An Investigation Of Modifications To The Tac Campaign Model, Efgan Denguer
An Investigation Of Modifications To The Tac Campaign Model, Efgan Denguer
Theses and Dissertations
This research investigates the cost and budget modifications to Mixmaster which is an aggregate version of the Theater Attack Model (TAM). Seven simple cost employment methods, a goal programming approach, a probabilistic approach for determining cost coefficients, and goal programming version of that probabilistic approach were applied to Mixmaster. Also, Mixmaster was enhanced with an additional leading constraint to incorporate the Air Force tactical considerations in a campaign scenario. The results favor the advantages of the goal programming approaches. In addition, the probabilistic approach introducing the time factor in the computations promises more accurate results, given that the required parameters …
Automating The Weekly Flight Scheduling Process At The Usaf Test Pilot School, Gary G. Foster
Automating The Weekly Flight Scheduling Process At The Usaf Test Pilot School, Gary G. Foster
Theses and Dissertations
This study investigated different scheduling solution approaches that could be automated and applied at the USAF Test Pilot School (TPS). Currently at the TPS, flight schedules are manually developed on a daily basis. Weekly flight schedules are not developed due to the large quantity of data that must be processed to develop a flight schedule for an entire week. A weekly flight scheduling approach would reduce the occurrence of scheduling problems and unbalanced resource utilization, both of which are often the result of a daily flight scheduling approach. In addition, posting a flight schedule for the entire week would improve …
Causal Univariate Spatial-Temporal Autoregressive Moving Averages (Starma) Modelling Of Target Information To Generate Tasking Of A World-Wide Sensor System, Kelly A. Greene
Theses and Dissertations
The Department of Defense employs a resource limited world-wide sensor system to detect certain events of interest. The purpose of this research was to establish a methodology using a univariate causal STARMA model for forecasting the relative probability of an event occurring in a geographical location during a time block of the day. These relative probabilities are used as input for a tasking model that assigns the scarce sensor resources so as to optimize the detection of these events. The STARMA model is appropriate for forecasting the relative probabilities because a definite temporal relationship and a definite spatial relationship exists …
Developing Cmmca Flight Profiles For Cruise Missile Tracking, Andrew C. Hachman
Developing Cmmca Flight Profiles For Cruise Missile Tracking, Andrew C. Hachman
Theses and Dissertations
The Air Force has recently acquired two aircraft dedicated for cruise missile tracking. These aircraft, known as the Cruise Missile Mission Control Aircraft (CMMCA), are responsible for collecting data from the missile and United States. Due to tracking and positively controlling the missile during live fire testing over the western the limited tracking radar range and the flight characteristics of the CMMCA, tracking cruise missiles through complex maneuvers is not always possible. A FORTRAN optimization, based on flight simulation and optimal control theory, was written in a prior thesis effort in order to determine optimal CMMCA flight profiles for tracking …
Optimization Of Stochastic Response Surfaces Subject To Constraints With Linear Programming, Robert G. Harvey
Optimization Of Stochastic Response Surfaces Subject To Constraints With Linear Programming, Robert G. Harvey
Theses and Dissertations
This research investigated an alternative to the traditional approaches of optimizing a stochastic response surface subject to constraints. This research investigated the bias in the expected value of the solution, possible alternative decision variable settings, and a method to improve the solution. A three step process is presented to evaluate stochastic response surfaces subject to constraints. Step 1 is to use a traditional approach to estimate the response surface and a covariance matrix through regression. Step 2 samples the objective function of the linear program (i.e., response surface) and identifies the extreme points visited. Step 3 presents a method to …
Confidence Interval Estimation For Output Of Discrete-Event Simulations Using The Kalman Filter, Randall B. Howard
Confidence Interval Estimation For Output Of Discrete-Event Simulations Using The Kalman Filter, Randall B. Howard
Theses and Dissertations
Discrete-event simulation is computer modeling of stochastic, dynamic systems. The Kalman filter is a Bayesian stochastic estimation algorithm. Because of the correlated nature of simulation output, it is difficult to apply the methods of classical statistics directly when constructing confidence intervals of discrete-event simulation parameters. Through the determination of a dynamics equation and application of the Kalman filter to simulation output data, three new confidence interval construction techniques have been developed. One technique obtains an estimate of the mean value and its associated variance from an estimated Kalman filter. The second technique utilizes Multiple Model Adaptive Estimation (MMAE) techniques to …
An Analysis Of Escort Formations, Mustafa Ilhan
An Analysis Of Escort Formations, Mustafa Ilhan
Theses and Dissertations
This study used computer simulation to investigate escort fighter formations unknown interceptor threat environment. A USAF computer simulation model, TAC, was used to simulate air combat between the escorts and the interceptors in several different combat scenarios. The escort formations were defined by the vertical and horizontal distances of the escort fighters from the main strike body. Interceptors were characterized as one of two types of fighters with dissimilar aircraft frames and missile firing ranges. A central composite design was used to mathematically model the effect of escort formations and interceptor type on the survivability of the bombers and escorts. …
Effects Of Facility Configurations And Scheduling Techniques On Aircraft Throughput For Warner Robins Alc Paint/Depaint Facilities, David V. Mcelveen
Effects Of Facility Configurations And Scheduling Techniques On Aircraft Throughput For Warner Robins Alc Paint/Depaint Facilities, David V. Mcelveen
Theses and Dissertations
The purpose of this research was to determine the effects of configuration options and dispatching rules on aircraft throughput for the WR- ALC paint/depaint facilities. A simulation model was constructed and used for this analysis as the primary means to conduct the research. The dispatching rules considered were first come first served, largest number in queue, shortest processing time, and a look ahead heuristic. Due to a reduction in the number of paint aircraft, no configuration option differing from the baseline significantly affected aircraft throughput. Dispatching rules were also found to produce no significant differences on aircraft throughput. Configuration options …
A Sensitivity Analysis Of Circular Error Probable Approximation Techniques, Peter Puhek
A Sensitivity Analysis Of Circular Error Probable Approximation Techniques, Peter Puhek
Theses and Dissertations
Several algebraic CEP estimates models were examined in this study. Each assumes that the crossrange and downrange miss distances of the sample data follow a bivariate normal distribution. The analysis determined the sensitivities of these models to changes in the parameters of sample size, bias, correlation, and ellipticity. The accuracy of each model is expressed in terms of relative error, and the parameter regions in which a certain method dominated as the most accurate were noted. In general, it was found that bias was the most significant parameter in determining the best CEP method. A simple method, based on the …
Spartan: An Instructional High Resolution Land Combat Model, David K. Cox
Spartan: An Instructional High Resolution Land Combat Model, David K. Cox
Theses and Dissertations
This project developed an instructional high resolution land combat simulation model. The purpose of this model is to demonstrate common techniques of modeling used in the present generation of US Army land combat models. This model is stochastic and uses an event scheduling type of discrete event time algorithm. The model represents a maximum of two six-man infantry squads in direct fire combat. The individual soldiers move, search for targets, engage targets, and react to hostile encounters. The data values provided will the model are all. generic and hypothetical. The model is only intended as a demonstration tool and has …
A Decision-Theoretic Approach To Recommending Action In The Air-To- Ground Aircraft Of The Future, Garrison H. Flemings
A Decision-Theoretic Approach To Recommending Action In The Air-To- Ground Aircraft Of The Future, Garrison H. Flemings
Theses and Dissertations
Designers of air-to-ground fighters of the future should consider including decision support systems to relieve pilots of some of the present workload. Those decision support systems should use utility theory. This work reviews two techniques of utility theory (decision trees and influence diagrams) and a new technique due to Morlan (probability ratio nets). The work includes a proposed structure for action recommendation systems in air-to-ground fighters of the future. The work describes an implementation of probability ratio nets. The work demonstrates the value of decision theory to air-to-ground fighters of the future by way of solving an example problem and …
Saber: Airland Combat Training Model Credibility Assessment And Methodology, David L. Scagliola
Saber: Airland Combat Training Model Credibility Assessment And Methodology, David L. Scagliola
Theses and Dissertations
Saber is a theater-level, airland combat training model, designed by a number of computer science and engineering students and faculty at the Air Force Institute of Technology (AFIT). Saber is intended to replace the Agile model, which is currently used at the Air Force Wargaming Center, Maxwell AFB, Alabama for Theater Warfare Exercise (TWX) training purposes. This thesis focuses on the progress made towards generating the Saber training model, its ability to meet the objectives specified by the Wargaming Center, and its ability to represent actual combat. Specifically, this thesis is directed towards characterizing, establishing a credibility assessment, and developing …
An Examination Of Wing Rock For The F-15, Michael T. Davison
An Examination Of Wing Rock For The F-15, Michael T. Davison
Theses and Dissertations
Wing rock in the F-15 was examined both analytically and experimentally. Using a previously developed model for the F-15, bifurcation analysis and continuation techniques were used to map out the periodic wing rock solutions and the equilibrium solutions leading up to wing rock. this was done for four maneuvers; a 1 g stall, rudder sweeps, constant bank turns and a symmetric pullup. To supplement this research, time history simulations were used to examine. the time history of wing rock. A study of stability derivatives was also done, to determine the critical parameters in wing rock. Bifurcation was also used to …
A Computer Based Educational Aid For The Instruction Of Combat Modeling, Richard S. Moore
A Computer Based Educational Aid For The Instruction Of Combat Modeling, Richard S. Moore
Theses and Dissertations
The Air Force Institute of Technology is one of few institutions that teaches combat modeling. Combat models are typically dynamic computer simulations of specialized dynamic processes. Great difficulty exists in portraying these dynamic and recurrent processes with conventional static diagrams. This thesis produced a computer-based instructional aid which presents animated examples of processes common to combat models, demonstrates a simple few-on-few aerial combat model, and encourages student exploration and interaction with these presentations. This aid provides dynamic examples of random number generation, detection processes, target selection, and target destruction. A complete combat model demonstrating a few-on-few air duel is animated …
Distributed Ray Casting For High-Speed Volume Rendering, Patricia L. Brightbill
Distributed Ray Casting For High-Speed Volume Rendering, Patricia L. Brightbill
Theses and Dissertations
The volume rendering technique known as ray casting or ray tracing is notoriously slow for large volume sizes, yet provides superior images. A technique is needed to accelerate ray tracing volumes without depending on special purpose or parallel computers. The realization and improvements in distributed computing over the past two decades has motivated its use in this work. This thesis explores a technique to speedup ray casting by distributed programming. The work investigates the possibility of dividing the volume among general purpose workstations and casting rays (using Levoy's front-to-back algorithm) through each subvolume independently. The final step being the composition …
Migrating A C-Based Cad Tool To An Object-Oriented Database/C++ Environment: Conversion Costs And Performance Analysis, Mark A. Roth, Timothy M. Jacobs
Migrating A C-Based Cad Tool To An Object-Oriented Database/C++ Environment: Conversion Costs And Performance Analysis, Mark A. Roth, Timothy M. Jacobs
AFIT Documents
his paper examines the potential of object-oriented databases to support complex design applications. To do this we migrated the Magic very large scale integrated (VLSI) circuit design tool written in the C language to a new environment in which Magic's existing file management code is replaced with a C++ language interface to the commercial object-oriented database management system (OODBMS) product Object Store. In our initial implementation we found the performance of this tool as implemented on the OODBMS to be marginally faster than the tool as currently implemented with a flat file system in several critical areas. Increased functionality, including …
High-Resolution Tvd Schemes For The Analysis Of 1. Inviscid Supersonic And Transonic Flows. 2. Viscous Flows With Shock-Induced Separation And Heat Transfer, Mark A. Driver
Theses and Dissertations
Application of TVD schemes to both inviscid and viscous flows is considered. The mathematical and physical bases of TVD schemes are discussed. First and second-order accurate TVD schemes and a second-order accurate Lax- Wendroff scheme are used to compute solutions to the Riemann problem in order to investigate the capability of each to resolve shocks, rarefactions, and contact surfaces. Second-order finite-volume and finite-difference TVD schemes are used to obtain solutions to inviscid supersonic and transonic cascade flow problems. TVD schemes are shown to be superior to the Lax-Wendroff family of schemes for both transient and steady-state computations. TVD methodology is …
Software Cost Estimating Models: A Calibration, Validation, And Comparison, Gerald L. Ourada
Software Cost Estimating Models: A Calibration, Validation, And Comparison, Gerald L. Ourada
Theses and Dissertations
This study was a calibration, validation and comparison of four software effort estimation models. The four models evaluated were REVIC, SASET, SEER, and COSTMODL. A historical database was obtained from Space Systems Division, in Los Angeles, and used as the input data. Two software environments were selected, one used to calibrate and validate the models outside their environment of calibration. REVIC and COSTMODL are COCOMO derivatives and were calibrated using Dr. Boehm's procedure. SASET and SEER were found to be un-calibratable for this effort. Accuracy of all the models was significantly low; none of the models performed better against the …
Investigation Of The Effects Of Increased Order Compensators In Mixed H2/H∞ Optimization, Scott R. Wells
Investigation Of The Effects Of Increased Order Compensators In Mixed H2/H∞ Optimization, Scott R. Wells
Theses and Dissertations
The problem of minimizing the 2-norm of one transfer function subject to an infinity-norm bound on another transfer function is examined for increased order controllers. In particular, the theoretical results of the full order case are extended to the higher order case, and SISO and MIMO numerical examples are given for increasingly higher order compensators. Some of the key proofs for higher order compensators include: the global minimum 2-norm is unachievable under output feedback for certain levels of gamma regardless of compensator order; the solution to the mixed H2/H infinity problem lies on the boundary of the infinity-norm constraint for …
Computation Of Planar Store Trajectories Using An Adaptive Grid Procedure, William D. Hack
Computation Of Planar Store Trajectories Using An Adaptive Grid Procedure, William D. Hack
Theses and Dissertations
The objective of this research was to compare a quasi-analytical, potential flow/three-degree-of-freedom model to an implicit-Euler algorithm for the calculation of store trajectories. The implicity algorithm uses a cell- centered, finite-volume, spatial discretization applied to the Euler equations, written in time-dependent, curvilinear-coordinates. A flux-differencing Roe scheme is employed to find the split-fluxes and the Steger/Warming flux-vector method is used to calculate the flux-Jacobians. The potential flow and implicit- Euler algorithm are combined with a three-degree-of-freedom algorithm to evaluate the planar, freefall trajectories of a simple store shape. The research uses two different grid-modification techniques in the implicit algorithm evaluation. Data …
The Application Of Kriging For Controlled Minimization Of Large Data Sets, Christopher Brodkin
The Application Of Kriging For Controlled Minimization Of Large Data Sets, Christopher Brodkin
Theses and Dissertations
Frequently, the quantity of data available is much greater than that which can be manipulated in an efficient and timely manner. This can cause several problems. The first, and probably most critical, problem is the excessive on-line storage needs of these huge data sets. Secondly, in the computer animation field, huge data sets may require excessive computational time for generation of each frame of a computer animation. Thirdly, computer screens have a limited resolution and need too much computational time removing excessive detail from images generated with a higher resolution than can be displayed. Lastly, too much time is required …
An Object-Oriented Database Implementation Of The Magic Vlsi Layout Design System, Timothy M. Jacobs
An Object-Oriented Database Implementation Of The Magic Vlsi Layout Design System, Timothy M. Jacobs
Theses and Dissertations
This thesis attempts to prove that the commercially available Object Store data management system provide the performance and functionality necessary to support a complex engineering design system. This is accomplished by modifying the Magic VLSI circuit layout design system to eliminate its current Unix file data management system and replace it with Object Store. The approach to this research effort includes a design recovery of the Magic system and identification of its ket data management functions. These functions are then modified to take advantage of the database management facilities of Object Store. Additional code is added to instrument performance measurement …
An Animated Graphical Postprocessor For The Saber Wargame, Gary W. Klabunde
An Animated Graphical Postprocessor For The Saber Wargame, Gary W. Klabunde
Theses and Dissertations
One of the most cost effective ways to learn and home the skills necessary to conduct and win a war is through the use of realistic computer simulations of conflict, or wargames. The Saber wargame was developed for just this purpose. Saber is a multisided, theater-level simulation developed by the Air Force Institute of Technology for the Air Force Wargaming Center. It models conventional, nuclear, and chemical warfare between aggregated air and ground forces. To aid in the realism, the effects of logistics, satellites, weather, and intelligence are represented. Saber provides an avenue for senior level joint service officers to …