Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (5732)
- Physical Sciences and Mathematics (2947)
- Aerospace Engineering (1674)
- Electrical and Computer Engineering (1343)
- Operations Research, Systems Engineering and Industrial Engineering (1245)
-
- Computer Sciences (1234)
- Business (992)
- Physics (919)
- Operational Research (609)
- Signal Processing (459)
- Civil and Environmental Engineering (422)
- Computer Engineering (414)
- Aviation (353)
- Electrical and Electronics (351)
- Social and Behavioral Sciences (349)
- Operations and Supply Chain Management (345)
- Materials Science and Engineering (335)
- Optics (330)
- Oceanography and Atmospheric Sciences and Meteorology (278)
- Navigation, Guidance, Control and Dynamics (252)
- Other Operations Research, Systems Engineering and Industrial Engineering (233)
- Human Resources Management (231)
- Systems Engineering (228)
- Atomic, Molecular and Optical Physics (198)
- Electromagnetics and Photonics (195)
- Aerodynamics and Fluid Mechanics (188)
- Environmental Sciences (188)
- Environmental Engineering (185)
- Nuclear Engineering (180)
- Applied Mathematics (178)
- Keyword
-
- #antcenter (380)
- #csra (134)
- Machine learning (93)
- Decision making (89)
- Algorithms (75)
-
- Global Positioning System (75)
- Image processing (73)
- Kalman filtering (65)
- Optimization (64)
- #afcec (62)
- Computer networks--Security measures (62)
- Drone aircraft (59)
- Computer security (57)
- Target acquisition (57)
- Neural networks (Computer science) (54)
- Software engineering (54)
- Additive manufacturing (52)
- Remote sensing (49)
- Flight control (48)
- Microelectromechanical systems (45)
- Computer vision (44)
- Artificial satellites (43)
- Decision support systems (43)
- #ctisr (42)
- Adaptive optics (42)
- Composite materials (42)
- Neural networks (41)
- Simulation (41)
- Wireless communication systems (41)
- Scheduling (40)
- Publication Year
- Publication
- Publication Type
- File Type
Articles 8581 - 8610 of 8786
Full-Text Articles in Entire DC Network
A Prototype Meta-Language And Automated Translator For Decision Analysis Problem Formulation, Jerry R. Puyear
A Prototype Meta-Language And Automated Translator For Decision Analysis Problem Formulation, Jerry R. Puyear
Theses and Dissertations
This thesis research effort develops a prototype meta-language for decision analysis problem description and automated software to translate the meta-language into a format useable by decision analysis software solvers. MELDA, the metalanguage developed, makes use of special symbols to provide a succinct language for the automation environment yet provides the means for user comprehension. Complete syntax and implementation rules are included. The MELADA translator software developed, DAT, stores the data given by MELADA in a file using prototype standard format, DASF, designed to hold all required data to solve a problem. DAT provides error checking and a message output file. …
Saber: A Theater Level Wargame, William F. Mann Iii
Saber: A Theater Level Wargame, William F. Mann Iii
Theses and Dissertations
This thesis provides a foundation to build a new theater level computerized wargame for the Air Force Wargaming Center, Maxwell AFB, AL to replace the Theater War Exercise (TWX), also known as Agile. Given a recently developed land battle, this thesis' effort links US Air Force doctrine with a conceptual model's framework and designs a new air battle module. The integration of both the air and land battles forms a new game, Saber. This thesis redefines the ground combat units of the land battle, and adds theater air defense units, bases and aircraft packages. This thesis introduces stochastic attrition between …
An Interactive Life Cycle Cost Forecasting Tool, John A. Gibson Iv
An Interactive Life Cycle Cost Forecasting Tool, John A. Gibson Iv
Theses and Dissertations
Enhancements were applied to an existing tool designed to estimate life cycle costs. These enhancements provide greater ease of data manipulation, additional options in developing models, and the ability to make modifications to suit the needs of the user. Life cycle costs can be generated quickly and easily. Analysis proved the amount of work done by the computer could be reduced with no loss of information. Additionally, the paths available to the user are shown graphically through flow charts--aiding in the learning process. The efforts of the user can now be directed towards developing models instead of spending those efforts …
A Study Of Variables To Help Predict Navigator Training Success And Classification, Gary A. Hagler
A Study Of Variables To Help Predict Navigator Training Success And Classification, Gary A. Hagler
Theses and Dissertations
This study attempted to build statistical models which could possibly be used to help predict an individual's final outcome of pass or fail from Undergraduate Navigator Training (UNT). Also, the research tried to develop models to help place a potential trainee into one of the three training tracks at UNT. The variables studied were test scores from a computerized testing device which measured psychomotor and cognitive skills of individuals entering training. The Air Force Officers Qualifying Test (AFOQT) scores were also variables considered. Data was from 317 trainees from the years 1988 to 1990. Discriminant analysis was applied in an …
The Utility Of Elliptical And Circular Confidence Regions For Hfdf Receivers, Paul T. Nemec
The Utility Of Elliptical And Circular Confidence Regions For Hfdf Receivers, Paul T. Nemec
Theses and Dissertations
This thesis investigates HFDF confidence region (CR) shape exhibited by geolocations in a search-and-rescue context. In Phase I, a Keeney-Raiffa multiattribute utility function was developed which allowed an analytical measure of preference between elliptical and equivalent- probability circular CRs. Phase II utilized a likelihood approach to establish CR shape for sample operational geolocations having multiple points of bearing intersections. For 12 sample Phase I geolocations, the elliptical CR always had higher utility than its corresponding circular CR. For accepted sample geolocations, a preference condition was developed whereby a circular CR would only be preferred over the corresponding elliptical CR if …
The Modeling Of Employment Decisions For Peacetime Contingency Operations, Michael C. Wilmer
The Modeling Of Employment Decisions For Peacetime Contingency Operations, Michael C. Wilmer
Theses and Dissertations
This research provided the conceptualization of a model that can be used to aid the operations planner in choosing employment strategies for peacetime contingency operations. The model uses object-oriented design and is constructed in two levels. The top layer of the model is a decision analytic model which provides a framework within which to structure the employment decision. It enables the user to quantify the probabilities of random events and the preferences of the commander and determine how these factors influence the decision. A Game Theory model is used to determine the probabilities with which the Red commander will adopt …
Multicriteria Network Routing Of Tactical Aircraft In A Threat Radar Environment, Ernst K. Isensee
Multicriteria Network Routing Of Tactical Aircraft In A Threat Radar Environment, Ernst K. Isensee
Theses and Dissertations
Real-time route planning for tactical aircraft has established a requirement for analytical tools which prescribe optimal solutions. The Air Force Electronic Warfare Center has developed a computerized routing aid which enhances the ability to plan tactical flight missions under real-time constraints. The decision aid known as the Improved Many-on-Many (IMOM) allows the user to subjectively evaluate flight routes within enemy radar coverages. However, the mission planner is required to intuitively assesses the survivability risks associated for each user defined route. As an alternative to this method, the deterministic procedures of dynamic programming and the shortest path algorithms offer techniques which …
Incorporating Value Systems In Strategic Force Analysis, Nancy D. Snyder
Incorporating Value Systems In Strategic Force Analysis, Nancy D. Snyder
Theses and Dissertations
Deterring potential Soviet aggression depends on our ability to hold at risk those assets they value most. This research investigates target valuation as an added dimension to force structure analysis. An extensive literature review is followed by the development and demonstration of a methodology defining development and use target values. The literature review covers arms control concepts to give a foundation for an important use of force structure analysis. It also covers measures of effectiveness. The final part of the review is comprised of definitions of perspectives on nuclear war. The methodology defines motivations for force structuring in the form …
Agility: Presentation And Flight Test Methods For The Operational Fighter Pilot, William R. Langdon
Agility: Presentation And Flight Test Methods For The Operational Fighter Pilot, William R. Langdon
Theses and Dissertations
This thesis develops both metrics and flight test techniques to measure agility. During development of both the agility metrics and the flight test techniques, previous work conducted by the agility community and the Flight Test Center at Edwards Air Force Base was used as a lessons learned tool to insure favorable results. Both simulator and flight testing was performed to validate the flight test techniques. During simulator testing several problems with the original flight test techniques were noted. Flight testing on the pitch agility flight test technique solved most of its problems but problems found during roll testing in the …
Thermo-Mechanical Fatigue Of A Fiber Reinforced Titanium Aluminide Composite, Mark A. Bates
Thermo-Mechanical Fatigue Of A Fiber Reinforced Titanium Aluminide Composite, Mark A. Bates
Theses and Dissertations
The thermo-mechanical fatigue behavior of a specific unidirectional fiber reinforced titanium aluminide composite was investigated. Three test specimens were subjected to in-phase thermo-mechanical cycling and four to out- of-phase thermo-mechanical cycling. The applied maximum mechanical stresses ranged from 500-800 MPa. The stress ratio of 0.1 was used for all tests. The temperature range was from 150-650 C and the resulting fatigue lives were in the 58-1487 cycles range. The out-of-phase test specimens failed sooner compared to their respective in-phase counterparts. In order to find out why, the test results were analyzed using a simple micromechanics analysis and compared. The fracture …
Development Of A Personal Computer Based Approach To Aircraft Parameter Identification, Mark S. Erickson
Development Of A Personal Computer Based Approach To Aircraft Parameter Identification, Mark S. Erickson
Theses and Dissertations
This thesis develops and tests a personal computer based approach to the aircraft parameter identification problem. The approach was tested analytically at the Air Force Institute of Technology, Wright-Patterson AFB, Ohio. These tests were conducted using simplified short period approximation and second-order transfer function models of longitudinal aircraft response. Initial evaluations were accomplished using simulated, noise free data. The longitudinal aircraft model was modified prior to flight test, for both convenience and necessity. This more complex model was evaluated during a flight test program at the USAFTPS, Edwards AFB, California. A T-38A aircraft was used as a tool to demonstrate …
Sensitivity Analysis For The Selection Of Linear Quadratic Regulator Weighing Parameters Q And R For Active Vibration Suppression Of A Cantilevered Beam, Steven L. Story
Sensitivity Analysis For The Selection Of Linear Quadratic Regulator Weighing Parameters Q And R For Active Vibration Suppression Of A Cantilevered Beam, Steven L. Story
Theses and Dissertations
There has been much interest during the past decade to develop and launch large space structures. The high cost of launching material into orbit will require that these structures be assembled in space using light weight elements which are vulnerable to dynamic excitations. Active control may be necessary to rapidly attenuate large amplitude vibrations. The active vibration control system is usually designed after the structure has been optimized. The integrated design of the control system and the structure may provide additional weight savings. This thesis presents a sensitivity analysis of the structure/ control optimization problem. The structure used is an …
Transfer Of 4gl Application From Ingres To Oracle, Adnan Altunisik
Transfer Of 4gl Application From Ingres To Oracle, Adnan Altunisik
Theses and Dissertations
This paper documents the transfer of 4GL applications from INGRES to ORACLE. As a result of a fast and conceptual change in computer languages, 4GLs were developed and evolved. These are programming support tools whose goal is, basically, to make the programs more efficient by reducing the number of instructions. Both ORACLE and INGRES database systems use 4GLs to develop applications. Their 4GL environments and their facilities for application development are investigated and explained in depth in this effort. The TWX application, which was originally implemented in INGRES by using its 4GL, is designed and reimplemented in ORACLE. This is …
Effects Of Colocation And Non-Colocation Of Sensors And Actuators On Flexible Structures, W. C. Lee
Effects Of Colocation And Non-Colocation Of Sensors And Actuators On Flexible Structures, W. C. Lee
Theses and Dissertations
This thesis compares the performance and robustness of colocated and non-colocated sensor/actuator pairs. Linear quadratic Gaussian and loop transfer recovery (LOG/LTR) procedures are used to design optimum controllers for three example problems. The first example is a single motion degree-of-freedom system having motion only about one axis. This type of system does not have any right half plane zeros for the non-colocated case; however, the thesis shows it behaves as a non minimum phase system. The second example is a Bernoulli-Euler beam which does not have RHP zeros. An optimum LOG/LTR controller can not improve the robustness of non minimum …
A Prolog-Based System For Hardware Verification, Kevin L. Sparks
A Prolog-Based System For Hardware Verification, Kevin L. Sparks
Theses and Dissertations
With the expanding number of components provided on a single digital chip, verification of digital designs is becoming a major problem. The more circuits one places on a single chip, the greater the number of input/output combinations which need to be checked. A paper by Barrow in 1984 discusses a Prolog-based hierarchical formal verification system which he calls VERIFY. Barrow provided a lot of information on what VERIFY can and cannot do, and on projected enhancements. He does not, however, mention how VERIFY actually performs the task of formal verification. This thesis will provide a description of one possible implementation …
A Common Interface Real-Time Multiprocessor Operating System For Embedded Systems, Michael S. Rottman
A Common Interface Real-Time Multiprocessor Operating System For Embedded Systems, Michael S. Rottman
Theses and Dissertations
Large real time applications such as aerospace avionics systems, battle management, and factory automation place many demands and constraints on the computing system not found in other applications. Software development is hindered by software dependence on the computer architecture and the lack of portability between systems. This thesis specifies and designs a real time multiprocessor operating system (RTMOS) that implements a consistent programming model, enabling the development of real time parallel software independent of the target architecture. The RTMOS defines the core functionality required to demonstrate the programming model. The RTMOS functional requirements are specified using Structured Analysis and Design …
The Boundary Element Method Applied To The Two Dimensional Stefan Moving Boundary Problem, Donald C. Vosika
The Boundary Element Method Applied To The Two Dimensional Stefan Moving Boundary Problem, Donald C. Vosika
Theses and Dissertations
This thesis considers problems for which the boundary is not known before the problem is solved and must be determined as part of the solution. We consider a time dependent problem which results in a moving boundary. We look at the heat conduction/diffusion equation in one and two spatial dimensions. We use Green's Theorem to yield a Volterra boundary integral equation which involves an unknown function on the moving boundary. We use the boundary element method to obtain a solution. Graphical results for the two dimensional problem are presented.
An Automated Red Player For The Theater Warfare Exercise, Karl W. Kabanek
An Automated Red Player For The Theater Warfare Exercise, Karl W. Kabanek
Theses and Dissertations
The Theater Warfare Exercise (TWX) is a two-sided, theater-level, decision-making exercise created, maintained and used by the personnel at the Air Force Wargaming Center. It is used to allow military officers to practice the decision-making process needed for the wartime employment of air power. An automated player was designed and a prototype implemented for the red (enemy) player using an expert system shell. The automated red player uses the TWX database that contains the data on the different units used in exercise. From the data the automated red player builds mission packages for the various types of missions required in …
Optimal Iterative Task Scheduling For Parallel Simulations, Joann M. Sartor
Optimal Iterative Task Scheduling For Parallel Simulations, Joann M. Sartor
Theses and Dissertations
The ultimate purpose of this research is to reduce the time needed for execution of parallel computer simulations. In particular, the impact of task assignment strategies is determined for parallel VHDL circuit simulations. The classical scheduling problem, which assigns n precedence-constrained tasks to m processors is NP-complete in all but the simplest cases. The problem of assigning simulation tasks is further complicated by the iterative nature of computer simulations: each task is required to execute multiple times as the simulation executes. This investigation develops a polynomial-time algorithm (the level strategy) which provides optimal assignment for iterative systems with specific constraints. …
A Fully Coupled, Automated Formation Control System For Dissimilar Aircraft In Maneuvering Formation Flight, Paul R. Rohs
A Fully Coupled, Automated Formation Control System For Dissimilar Aircraft In Maneuvering Formation Flight, Paul R. Rohs
Theses and Dissertations
This study developed a fully automated formulation control system, capable of controlling a number of like or dissimilar aircraft in maneuvering formation flight. C-130 fixed wing aircraft and H-53 helicopters were modelled in various formulations and simulated through a mix of maneuvers. External formation guidance was assumed as a single data burst of nominal function guidance commands and separation distances for each wing aircraft in the formation. No communication was assumed between formation aircraft. Wing aircraft track lead aircraft maneuvering with an ideal on-board sensor, maneuvering to maintain relative position. It was determined that lead aircraft inputs must be attenuated …
A Navigation Reference System (Nrs) Using Global Positioning System (Gps) Aiding, Richard D. Stacey
A Navigation Reference System (Nrs) Using Global Positioning System (Gps) Aiding, Richard D. Stacey
Theses and Dissertations
To quantify the performance abilities of existing or proposed navigation systems, the U.S. Air Force has for the last several years compared the performance of the system under test to the performance of a baseline navigation system known as the Completely Integrated Reference Instrumentation System (CIRIS). CIRIS obtains a highly accurate navigation solution by combining the output from three major subsystems: inertial navigation system (INS) information, barometric altitude information, and range and range-rate data from ground transponders which have been precisely surveyed. Although the navigation solution produced by CIRIS is highly accurate, it will soon be inadequate as the standard …
An Environmentally Controlled Chamber For The Study Of Radon Detection, William R. Wharton Jr.
An Environmentally Controlled Chamber For The Study Of Radon Detection, William R. Wharton Jr.
Theses and Dissertations
A system was developed to dynamically control and monitor the environment and radon concentration within a glovebox chamber for the study of radon. The system is designed around a personal computer workstation which automates the entire system. The radon concentration is determined by monitoring the count rate from radon and its progeny which are continuously circulated from the radon chamber through a Lucas Cell detection system. This information is then used as a base for controlling a radon injection system. When the concentration within the glovebox drops, the system injects a precisely-measured volume of high activity radon gas into the …
An Assessment Of The Accuracy Of Semi-Empirical Quantum Chemistry Calculations Of The Mechanical Properties Of Polymers, James R. Shoemaker
An Assessment Of The Accuracy Of Semi-Empirical Quantum Chemistry Calculations Of The Mechanical Properties Of Polymers, James R. Shoemaker
Theses and Dissertations
The ultimate mechanical properties of polymers, assuming perfect morphology, will be limited by the mechanical properties of a single, ideal polymer chain. Previous calculations of polymer chain moduli using semi- empirical (SE) quantum chemistry methods have resulted in modulus values much higher than experimentally measured. This study investigated the error in the calculated inherent to the method of calculation by comparing SE results for C-C bond potentials in two well characterized polymers, polyethylene and polydiacetylene. It was found that the SE calculation systematically overpredicted bond stiffness in these polymers by approximately 25% to 30%. This is the upper limit on …
A Computer Simulation Of Braitenberg Vehicles, Eric B. Werkowitz
A Computer Simulation Of Braitenberg Vehicles, Eric B. Werkowitz
Theses and Dissertations
In his treatise, Vehicles: Experiments in Synthetic Psychology, Valentino Braitenberg used simple, autonomous vehicle designs to illustrate the principles behind animal nervous system organization and operation. The goal of this effort was to produce a computer program to allow a researcher to experiment with these concepts and to analyze their performance using methods employed by experimental psychologists. The resulting program allows the user to design vehicles that respond to changes in their environments and that have the ability to adapt their behavior, using a learning algorithm developed by Teuvo Kohonen. The vehicle designer is free to select sensor attributes, …
Hardware Upgrade Of A Segmented Drum Assay System, Claude A. Irvine
Hardware Upgrade Of A Segmented Drum Assay System, Claude A. Irvine
Theses and Dissertations
This paper describes the conversion of a DEC PDP-11/05 computer system, previously used in Canberra's Model 2220B segmented gamma scanner, with an IBM PC. Two tasks necessary for completion of the project involved reestablishing communications with a Canberra Series 35+ multi-channel analyzer and a scan table controller. An additional serial/parallel card was installed in the PC to reinstate comunications with the multi-channel analyzer. For computer control of scan table controller operations a digital input/output card was used along with an external electromechanical relay board; when implemented together this hardware setup replaces functions that were normally processed through a motion control …
Construction, Calibration And Use Of A Neutron Time-Of-Flight Spectrometer, Charles L. Wood
Construction, Calibration And Use Of A Neutron Time-Of-Flight Spectrometer, Charles L. Wood
Theses and Dissertations
The energy spectrum of a 5 curie Pu-Be neutron source is determined by use of a neutron time-of-flight spectrometer. This spectrometer measures the time it takes for a neutron to travel between two plastic scintillator detectors. Using a fixed distance for travel, a time spectrum is generated which is then unfolded into the energy spectrum of the source. The different aspects of equipment selection, connection and calibration of the system are described. With the resolved spectrum the energy resolution of the spectrometer is determined by using a Monte Carlo simulation of the experimental set-up. A dual- parameter experiment is conducted …
The Self-Shielding Of Fallout Gamma Rays By Terrain Roughness, Mark S. Herte
The Self-Shielding Of Fallout Gamma Rays By Terrain Roughness, Mark S. Herte
Theses and Dissertations
The study presents a first order calculation of the self-shielding of nuclear weapon fission fragment gamma rays by surface roughness (microscopic terrain irregularities). To simulate fallout particles, polymer microspheres were deposited on slides containing samples of soil, concrete and asphalt roofing shingles. Scanning electron microscopy was used to photographically map the surfaces. The thickness of surface irregularities at various angles was measured by converting the photographs to digital images. Measurements showed a dependence upon the surface type, but not upon particle size. Average values of the measurements were modelled using a homogeneous buried source. With this geometry, dose rates were …
The Optimal Location Of Geodss Sensors In Canada, Pierre J. Forgues
The Optimal Location Of Geodss Sensors In Canada, Pierre J. Forgues
Theses and Dissertations
This thesis studies the maximal coverage p-median and the set covering facility location problems as applied to the GEODSS location problem. The classical single-objective mathematical formulations of the p-median and set covering problems are converted into network-flow formulations and various solution methods are developed using a scaled-down version of the GEODSS problem. The next step is the introduction of a second criterion function into the problem. This second function consists of minimizing the sum of the variance in coverage at the selected locations. Research reveals the deficiencies of MOLP (multiobjective linear programming) techniques in generating the efficient frontier of an …
Hybrid Wafer Scale Microcircuit Integration -- [ 4989063 ], Edward S. Kolesar Jr.
Hybrid Wafer Scale Microcircuit Integration -- [ 4989063 ], Edward S. Kolesar Jr.
AFIT Patents
A wafer scale integration arrangement wherein integrated circuit die of varying size, fabrication processes, and function are commonly mounted in the same host wafer using a filled epoxy material of special characteristics. The mounting epoxy material also serves as a substrate for the die interconnecting conductors in regions adjacent the mounted die. The described assembly also includes a newly available photosensitive polyimide material as a planarization and passivation covering for the die and host wafer and as a mounting surface for an interconnecting metal conductor array. Multiple levels of interconnection metal. Fabrication processes for the die to host wafer attachment …
Three Degrees Of Freedom Compliant Motion Control For Robotic Aircraft Refueling, Clayton M. Andersen
Three Degrees Of Freedom Compliant Motion Control For Robotic Aircraft Refueling, Clayton M. Andersen
Theses and Dissertations
The Air Force Institute of Technology (AFIT) supports on-going research in application of robotic technology to enhance assembly tasks. As a testbed, AFIT supports the ground-based aerial refueling project, with an emphasis on visual servoing techniques and compliant motion control. This thesis focuses on compliant motion control. Previous research developed the testing environment, which includes a PUMA-560 industrial manipulator, and a half scale mock-up of an aerial refueling system. This effort corrected and expanded the existing two degree of freedom (DOF) compliant controller to three DOF. Three DOF compliance was demonstrated by inserting the refueling nozzle into the receiver port. …