One of the most important activities in the systems engineering process is the determination of the best implementation method from a set of alternatives. This project describes a process that can be followed to evaluate a set of implementation alternatives. This process consists of performing the following activities: Definition of the need, requirements and functional analysis, evaluation of the alternatives, requirements validation, and risk identification. To clarify the activities in the evaluation process, the project follows a case study in which the XYZ Corporation determines the best implementation approach for providing access to a remote database over low speed communications lines. Three alternatives were evaluated by the XYZ Corporation. After performing the evaluation, an HTML only implementation approach was selected. This implementation had the highest perfonnance and dependability compared to the other alternatives. Regional users will use a Netscape browser to view HTML pages stored at the corporate headquarters. A web seNer located at the corporate headquarters will interface with the database seNer by performing the required additions, updates, and queries to the corporate database. The web seNer will also fonnat the returns into HTML pages for viewing at the regional sites. / Master of Science

<p>The objective of this paper is to show how relational database schema can be transformed into static object-oriented database schema. First, data definition in the relational model and the object model are described. Next, the transformation rules are explained. This is followed by an illustration of an algorithm used to construct object-oriented schema out of relational schema. Finally, the algorithm is implemented through the use of C++.</p> / Master of Science

<p>The international aviation industry has embraced a revolutionary future concept of operations known as "free flight". The free flight concept allows each aircraft to travel between destinations using flexible fuel efficient routes rather than the current fixed jet routes. Flying the present inefficient fixed routes costs the airlines millions of dollars annually in fuel and personnel costs. Additionally, because there are only a limited number of the current "highways in the sky", aircraft in the United States and Europe regularly experience delays waiting for their turn to access the jet-routes. This present system also constrains future air traffic growth, particularly in oceanic airspace.</p> <p> To address these deficiencies, direct pilot-to-controller communications are required in oceanic airspace managed by the United States. This functional requirement for direct pilot-to-controller communications is not being met by the present oceanic air-to-ground communications system.</p> <p>Using a systems engineering approach, this project determines the feasibility of extending domestic air traffic control communication systems into the U.S. managed oceanic airspace over the Gulf of Mexico. Two feasible alternatives are evaluated for achieving this capability.</p> / Master of Science

see document / Master of Engineering

Master of Science

see document / The conceptual and preliminary design of the Dynamic Link Tool (DLTool) System are presented. The DLTool System performs moderate fidelity, satellite radio frequency (RF) interference and communications analysis. The primary customer of the DLTool System is Program 607 of Lockheed Martin Corporation (LMC) in Valley Forge, Pennsylvania. The system will dramatically improve the existing satellite RF interference analysis capabilities of Program 607, which are currently inadequate. Most-importantly, the DLTool System will reduce the required analysis time for satellite RF interference problems from approximately 6 hours to 1 hour. The DLTool System is intended to provide the capability to quickly predict or anticipate potential periods of RF interference. The design of the DLTool System includes an analysis of the needs of the customer, a feasibility study, the definition and allocation of operational and maintenance requirements, and the functional analysis of the system. The system is designed for a workstation-based local area network with simultaneous users, and includes a graphical user interface for input and output. The core component of the DLTool System is customized c++ code that performs the computational analysis of user defined satellite-ground station scenarios. The primary users of the system are communication engineers who will use the DLTool System to study RF interference issues for their customer. / Master of Science

Master of Science

Master of Science

In today's society, the disposal of hazardous and non-hazardous waste is an ever growing problem. Legislation has become increasingly stringent with regard to protecting the environment from groundwater contamination. As documented by the EPA, the proportion of waste disposed of in landfills has steadily declined throughout the past thirty years due to source reduction, waste diversion to combustion facilities, and material recovery efforts. <p>This project examines the effects of material recovery levels on landfill life-cycle costs. A model has been developed to study the relationships between the operational costs, profit, and material recovery levels. The landfill in King George County, Virginia is used as the basis for studying the effects of increasing the current state required material recovery level from 25% to 50%. / Master of Science

<p>Air, nitrogen, argon and carbon dioxide were used as the atomizing gas in an 'air-assist' spray nozzle to determine the effect of these gases on mean droplet size, number density, velocity and their distributions in kerosene fuel spays and spray flames using a two dimensional phase Doppler interferometer. Data have been obtained with these atomizing gases using a base, air assisted case as a reference, since this is the most commonly used atomizing fluid in almost all applications. Comparisons were made between the gases on a mass and momentum flux basis. Both burning and nonburning sprays were investigated. The results show significant differences in atomization characteristics from the atomizer with different gases and under conditions of constant mass and momentum flux of the gas. The results also show that the presence of oxygen in the air atomized sprays assists in the combustion process, since it produces smaller and faster moving droplets, especially at locations near to the nozzle exit. In nonburning sprays, droplets had similar size and velocity. Lighter gases such as nitrogen more effectively atomized the fuel in comparison to the denser gases. Argon and carbon dioxide produced larger, slower moving droplets than air and nitrogen assisted cases in both the burning and nonburning sprays. Flame photographs revealed the argon and carbon dioxide atomized flames to have greater luminosity than air or nitrogen atomized flames.</p> / Master of Science