Engineering Commons^™

A Study In Use And Management Of De/Anti-Icing Constituents With Regard To New Storm Water Legislation, Darren P. Gibbs, Bruce L. Willing

Theses and Dissertations

This research identified management practices of airfield and aircraft de/anti-icing constituents which may be implemented to deal with new storm water legislation. Storm water regulations require that deicing operations obtain a NPDES permit for discharges into storm water runoff which may mandate the use of Best Management Practices. An FAA civilian airport survey and a USAF survey were used, with a literature search, to identify practices of de/anti- icing constituents. Four major constituents are used-glycol, urea, calcium magnesium acetate, and sodium formate. Concerns of uncontrolled release of the constituents include high BOD rates, nitrate and nitrite enrichment, impaired aesthetic water …

A Model Action Plan To Reduce The Use And Release Of Cfcs In Air- Conditioning And Refrigeration Systems, David W. Andrews, Daniel P. Ellert-Beck

Theses and Dissertations

This study investigated methods to reduce the use and release of chlorofluorocarbon (CFC) refrigerants and evaluated alternatives to CFCS in air- conditioning and refrigeration systems. A life cycle cost (LCC) analysis formed the basis for evaluation. A literature review examined applicable CFC directives, containment methods, replacement refrigerants, and alternative processes. The results of the LCC analysis showed that maintaining the existing CFC system was always the least costly alternative. When forced to replace a CFC reciprocating package unit, the best replacement was a non-CFC reciprocating unit. The most practical replacement for reciprocating chillers was a new reciprocating chiller for systems …

Cultural Resources Management In The United States Air Force: Development Of A Planning Primer, Steven R. Becker, Russell R. Hula

Theses and Dissertations

The purpose of this study was to produce a USAF base-level primer for use as a guide to requirements, standards, and procedures concerning the preservation of cultural resources. Cultural resources include buildings, sites, districts, structures, and objects that have significant scientific, historic, or cultural value. The research had two major objectives: (1) Identify existing sources of cultural resource information through a review of legal requirements, regulations, USAF policy documents, and other sources such as data bases. (2) Produce a 'cultural resources management primer' after identifying the appropriate characteristics of a primer. This product could then be used by novice personnel …

A Comparison Of Computer And Paper Media In Psychological Testing, Anthony C. Hensley, Timothy R. Morris

Theses and Dissertations

This study examined differences based on computer and paper modes of administration in psychological testing. The hypotheses tested were the expectations that scores on the computer Wonderlic Personnel Test (WPT) would be higher than the paper version and subjects would report higher levels on the computer Vocational Preference Inventory (VPI) scales. A counterbalance experimental design with two experimental groups was used. The subjects were volunteers from the Air Force Institute of Technology (AFIT) and Wright State University (WSU); 90 subjects completed the study. This included 75 students from AFIT and 15 from WSU; 69 subjects were male and 21 were …

An Investigation Of Integrated Weapon System Management Implementation Issues, Scott A. Dalrymple, Lester F. Pietraszuk

Theses and Dissertations

This thesis investigated Integrated Weapon System Management implementation issues. Five functional areas were examined: Contracting, Engineering, Financial management, Program Management, and Test Management. Data was collected through interviews. The most significant lessons learned were to establish a direct chain of command and to use TQM principles. Program business practices were changed by increasing Product Center/ALC interaction and implementing a single joint CCB. Program personnel obtained useful guidance from other IWSM programs and from the information products distributed by HQ AFMC. Communication improvements included increased teleconference capability and establishment of a Local Area Network. Cultural differences between centers, insufficient initial guidance, …

Pollution Prevention, An Investment Decision Model To Assess Financial Feasibility For Application To Air Force Processes, Debra S. Rankin, Clare R. Mendelsohn

Theses and Dissertations

This research develops a Pollution Prevention Investment Decision Model (PPIDM) to evaluate the financial feasibility of pollution prevention alternatives. The PPIDM provides managers with simple, systematic, and flexible guidelines for making accurate and expedient decisions when considering pollution prevention alternatives. The model illustrates that a comprehensive analysis is not always necessary. The PPIDM gives managers the flexibility to adjust the economic feasibility criteria based on top management's perceptions of the political environment. When top management places a very high value on political considerations, economic criteria is insignificant and the project may be implemented immediately without further analysis. The PPIDM takes …

An Evaluation Of Schedule Metrics Used Within Aeronautical Systems Center, Robert J. Hayes, Lawrence M. Miller

Theses and Dissertations

This study focused on a selected group of schedule metrics in use at Aeronautical Systems Center (ASC) acquisition program offices. Over 300 metrics were collected from the System Program Offices (SPOs). The metrics data were sorted into the categories of cost, schedule, and performance. In order to narrow the scope of the project, the team decided to focus on schedule metrics. Seven of the most common schedule metrics were selected for evaluation by a group of five experienced acquisition professionals. The group was asked to input the likely behaviors driven by the metrics being addressed by the study. Next, they …

Development And Application Of A Methodology For Evaluating Type Ii Expired Shelf Life Hazardous Material Generation In The United States Air Force, Jennifer Putz

Theses and Dissertations

The Pollution Prevention Act of 1990, Air Force Directive 19-4, and the Air Force Pollution Prevention Plan require installations to reduce the amounts of hazardous waste generated. To meet the requirements set forth in these documents, each waste stream containing a hazardous waste needs to be identified and characterized for changes in policies or procedures that would reduce the hazardous waste generated. This research develops a methodology to determine the amount of materials with a type II shelf life that is disposed of as hazardous waste because the shelf life expired while the material was in base supply storage. This …

Range Scheduling Automation For The Air Force Satellite Control Network: A Case Study In Computer System Development, Donald J. Aitken, Steven C. Bishop

Theses and Dissertations

This study explored the factors influencing divergent outcomes of two computer system development efforts which were undertaken to fulfill the same requirement for computer automation of a manual resource scheduling process. The first project employed the traditional waterfall approach to system development, but resulted in user rejection and cancellation after considerable resources and effort had been expended. The second project employed prototyping and both the process and the product were well received by the users and ultimately produced an operational system. Analysis yielded eight contributory factors to the failure of the first effort. Three of these were related to the …

The Theory Of Constraints Applied To Project Scheduling: The Critical Chain Concept Defined, Andrew D. Ingram, Paul E. Scherer

Theses and Dissertations

This research applies the Theory of Constraints' principles to a project management environment. The Constraint Theory developed by Dr. Eliyahu M. Goldratt has been successfully applied in many manufacturing settings. Researchers are now beginning to apply Theory of Constraints' principles and techniques outside the manufacturing environment. Specific objectives of this research effort include: to develop and demonstrate a resource constrained project scheduling algorithm based on the Theory of Constraints' principles and techniques: to perform a detailed comparison of the manufacturing and project scheduling environments designed to support algorithm development; and to lay the foundation for additional research in this area …

Comparison Of Four-Cursor Buttons Vs Joystick To Access Computerized Technical Information From An Integrated Maintenance Information System, Gerald E. Streff, Robert H. Gundel

Theses and Dissertations

The purpose of this thesis was to evaluate the use of four-cursor buttons versus a joystick device to present technical order information on a portable maintenance aid computer for aircraft technicians in a maintenance environment. Studies to date have verified the superiority of computer-presented technical orders when compared to current paper-based systems; this research investigated the effectiveness of these computer-based systems when technicians used a joystick or four-cursor button to display desired technical information. A comparison was made as to technician performance using a portable maintenance aid at the 4950th Test Wing, WPAFB OH. A total of thirty-two maintenance technicians …

An Assessment Of Afit Sys200, 'Acquisition Planning And Analysis', As A Broadening Course Under Apdp, Daryl J. Hauck, Charles A. Manship

Theses and Dissertations

This study assessed AFIT's SYS200 course, 'Acquisition Planning and Analysis,' to determine whether it serves adequately as a broadening course under the Acquisition Professional Development Program (APDP). APDP certification requires persons in eight acquisition functional disciplines (Acquisition Logistics, Systems R and D/ Engineering, Program Management, etc.) to complete SYS200. Three complementary measures (assessing knowledge, self- efficacy, and a supervisor assessment) were used to determine whether SYS200 conveyed its curriculum effectively to members of all functional disciplines. The results showed that SYS200 attendance produced substantial increases in acquisition-related knowledge, self-efficacy, and supervisor assessments for all functional disciplines. In all three measures, …

A Methodology For Project Selection Using Economic Analysis And The Analytic Hierarchy Process, Jeffrey L. Battin, Thomas J. Bender

Theses and Dissertations

This study examined the applicability of a multiple criterion decision making method, known as the Analytic Hierarchy Process (AHP) , to economic analysis decisions involving project selection. Through a survey of the literature and current practices, it was determined that qualitative criteria were not adequately represented in a typical economic analysis of projects. Several MCDM methods were examined and the AHP was found to be the most promising technique to rate projects on a ratio scale. Two types of project selection problems, those involving nonmutually exclusive alternatives and those involving mutually exclusive alternatives, were examined. It was determined that the …

Design Provisions For Cold-Formed Steel Column And Beam Columns, Committee On Specifications For The Design Of Cold-Formed Steel Structural Members

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Analysis Of Traffic Accident Data In Kentucky (1987-1991), Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

This report includes an analysis of traffic accident data in Kentucky tor the years of 1987-1991. A primary objective of this study was to determine average accident statistics for Kentucky highways. Average and critical number and rates of accidents were calculated for various types of highways in rural and urban areas. These data can be used in Kentucky's procedure to identify locations that have abnormal rates or numbers of accidents.

Another objective of this study was to provide data which can be used in the preparation of the problem identification portion of Kentucky's Annual Highway Safety Plan. County and city …

1992 Safety Belt Usage Survey And Evaluation Of Effectiveness In Kentucky, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of the survey was to establish 1992 safety belt and child safety seat usage rates in Kentucky. Data were collected at 100 sites and combined based on vehicle miles travelled for a given type of highway, rural or urban location, and county population category. Also included in this report is an analysis of accident records evaluating the effectiveness of safety belts.

Statewide usage rates were 41 percent for drivers and front-seat passengers (over 19 years of age) and 62 percent for children under four years of age (front and rear seats). Driver usage rates increased in 1992 compared …

Bs News

Building Services Engineering

No abstract provided.

Output Frequency Changes In A Commercial Rubidium Clock Resulting From Magnetic Field And Microwave Power Variations, Edward B. Sarosy

Theses and Dissertations

This report shows the relationship between output frequency shifts and the absorption cell magnetic field during microwave power fluctuations on a commercial rubidium frequency clock. Changes in the clock output frequency relative to the 10 MHz reference were monitored as changes in the absorption cell magnetic field (0.01 to 1.0 Gauss) and changes in the cell's interrogation microwave power were varied from the nominal specification (PO) at four discrete values (+1.3. -1.1, -2.2, -4.OdB). The maximum normalized output frequency shift of 1.4x10^-10 occurred at--4dB. The maximum normalized frequency change for the +1.3 and -1.1 dB data is about 3 …

Analysis Of Standard Type Unit Development, Jeffrey M. Hess, Merry D. Wermund

Theses and Dissertations

This research study examined the standard type unit development process for the Air Force. Current standard type unit development procedures were determined by a literature review. The literature review, with the interviews, provided information regarding the history of, purpose for, and possible alternatives for developing standard type units. A Delphi questionnaire was developed to determine how well the current process works, how standard type units worked for Desert Shield/Storm, and possible ways to improve the development process. This questionnaire was distributed to F-15 units, F-16 units, and major command personnel in Tactical Air Command (now Air Combat Command). All three …

Minimum Separation For Single-Layer Channel Routing, Ronald I. Greenberg, F. Miller Maley

Computer Science: Faculty Publications and Other Works

We present a linear-time algorithm for determining the minimum height of a single-layer routing channel. The algorithm handles single-sided connections and multiterminal nets. It yields a simple routability test for single-layer switchboxes, correcting an error in the literature.

A Comparison Of Aircraft Maintenance Organizational Structures, Wesley C. Davis, Sanford Walker

Theses and Dissertations

This study compares the aircraft maintenance structure being implemented by General Merrill A. McPeak with that of the previous structure typified by TACR 66-5. Historical aircraft data is used to compare organizational structures. Data from the USAF and USN is used to build regression models to determine if organizational structure contributes to combat capability. Statistical tests are used to determine if a significant difference exists between the two organizational structures. Regression analysis and comparison of the results lead the researchers to conclude that a significant difference exists in the performance measures of COMO and Objective Wing organizations. While many reasons …

Modification, Reimplementation And Studies Using The Meisner Model Of The Heart, Ari Zvi Zivotofsky

Theses

The study of left ventricular filling in both the normal and the pathological heart is of great importance. A computer model simulation of the heart with emphasis on mitral flow was designed by Meisner in 1986 and implemented in QuickBASIC. This paper discusses how the original program was altered to be able to perform "Parameter vs. Parameter" runs in which it can be observed how varying an input parameter affects output parameters. The output data is then formatted in such a way that it can be used by QUATTRO PRO, a standard spreadsheet package, to yield graphical outputs.

In addition, …

Racking Performance Of Plasterboard-Clad Steel Stud Walls, B. Golledge, T. Clayton, G. Reardon

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

It is recognised that structural design efficiency in domestic and similar structures can be improved when the composite behaviour and contribution of all materials in the permanent structure can be fully recognised in the structural design of the frame. The ability to achieve this Improvement is currently limited by the need 10 rely on empirical test results for standardised building elements when considering the composite behaviour of the entire structure. The existing test methodology for determining the shear strength of plasterboard lined steel stud walls leads to an excessively conservative design of the complete structure. Since the test configuration is …

Test Of A Full Scale Roof Truss, Yao - Jie Guo, Shan-Feng Fang

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

In order to obtain information of ultimate capacity and destructive characteristics of a roof truss, the test of a full scale roof truss was carried out based on the test results this article has analysed the destructive mechanism and presented the suggestions of improvement to design and fabrication.

Practical Constraints Pertinent To The Design Of Neural Networks, Said Sadek Abdallah, Rufus H. Cofer

Electrical Engineering and Computer Science Faculty Publications

in designing a feedforward neural network for numerical computation using the backpropagation algorithm it is essential to know that the resulting network has a practical global minimum, meaning that convergence to a stationary solution can be achieved in reasonable time and using a network of reasonable size. This is in contrast to theoretical results indicating that any square-integrable (L2) function can be computed assuming that an unlimited number of neurons are available. A class of problems is discussed that does not fit into this category. Although these problems are conceptually simple, it is shown that in practice convergence to a …

Down-Aisle Stability Of Rack Structures, J. Michael Davies

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

No abstract provided.

An Experimental Study Of Shear Wall Units, Atsuo Tanaka, Hiroshi Hasuda, Kazumi Sakae, Tutomu Tumori

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

No abstract provided.

Dynamic Analysis Of Space-Related Linear And Nonlinear Structures, Paul A. Bosela, F. J. Shaker, D. G. Ertis

Civil and Environmental Engineering Faculty Publications

In order to be cost-effective, space structures must be extremely light-weight, and subsequently, very flexible structures, The power system for Space Station 'Freedom' is such a structure. Each array consists of a deployable truss mast and a split 'blanket' of photo-voltaic solar collectors. The solar arrays are deployed in orbit, and the blanket is stretched into position as the mast is extended. Geometric stiffness due to the preload make this an interesting non-linear problem. The space station will be subjected to various dynamic loads, during shuttle docking, solar tracking, attitude adjustment, etc. Accurate prediction of the natural frequencies and mode …

Minimization Of Exclusive Sum Of Products Expressions For Multiple-Valued Input Incompletely Specified Functions, Ning Song

Dissertations and Theses

In recent years, there is an increased interest in the design of logic circuits which use EXOR gates. Particular interest is in the minimization of arbitrary Exclusive Sums Of Products (ESOPs). Functions realized by such circuits can have fewer gates, fewer connections, and take up less area in VLSI and especially, FPGA realizations. They are also easily testable. So far, the ESOPs are not as popular as their Sum of Products (SOP) counterparts. One of the main reasons it that the problem of the minimization of ESOP circuits was traditionally an extremely difficult one. Since exact solutions can be practically …

Remote Driving With Reduced Bandwidth Communication, Fred W. Depiero, Timothy E. Noell, Timothy F. Gee

Electrical Engineering

Oak Ridge National Laboratory has developed a real-time video transmission system for low-bandwidth remote operations. The system supports both continuous transmission of video for remote driving and progressive transmission of still images. Inherent in the system design is a spatiotemporal limitation to the effects of channel errors. The average data rate of the system is 64,000 bits/s, a compression of approximately 1000:1 for the black and white National Television Standard Code video. The image quality of the transmissions is maintained at a level that supports teleoperation of a high-mobility multipurpose wheeled vehicle at speeds up to 15 mph on a …