A case study of the object-oriented development of two computer games using commercially available products was conducted. The games were constructed for use on Apple Macintosh computers using a C+ + like programming language and an accompanying object-oriented class library. Object-oriented techniques are compared with procedure oriented techniques, and benefits of object-oriented techniques for code reuse are introduced. The reuse of object-oriented code within a target domain of applications is discussed, with examples drawn from the reuse of specific functions between the two games. Other reuse topics encountered in the development effort which are discussed: reuse of operating system routines, reuse of code provided by an object-oriented class library, and reuse of code to provide functions needed for a graphical user interface. / Master of Science

Telecommunications capabilities have increased dramatically in recent years. Especially significant is the introduction and tremendous growth of mobile telephone communications. Given the limitations of current mobile phone communications and the need for truly global person-to- person capabilities, an enhanced satellite-based system is presented as a feasible means to link portable telephones throughout the world. <p>Using systems engineering and the systems approach, the choice of using a satellite system vice other methods is made from a feasibility analysis. Following this choice, operational requirements are established. Based upon these requirements, two different satellite constellations are presented for consideration: a three-satellite geosynchronous constellation and a multi-satellite low earth orbiting (LEO) constellatIon. The advantages and disadvantages of each configuration are explored and the LEO constellation is chosen. Throughout the paper, systems engineering and its methodologies are used to illustrate how such a system might be developed using the systems approach. / Master of Engineering

Master of Science

<p>The goal of this project was decode and display a run-length encoded image, and to apply error concealment techniques to the decoded image. The software was written in the C programming language, a language learned during the course of this project. This software was written to read a run-length encoded ASCII file and translate it to a bit-mapped ASCII file. The software can display the bit-mapped image on a video screen and print it on a laser printer.</p> <p> The software also implements four error concealment techniques and displays the improved image on the video screen and on a laser printer.</p> <p> This software was written for the U.S. Coast Guard's Standard Workstation, running the Unisys Corporation's Burroughs Technology Operating System (BTOS), using the BTOS C compiler. Most of the code should be transportable to other operating systems, but the display functions make use of system library functions, which may not be available on other operating systems. / Master of Science

<p>This project report defines network robustness and discusses capability indicators that could be used to analyze network robustness. Growing dependence on telecommunication networks and recent network outages have focused attention on network robustness. The National Communications System (NCS), a confederation of 23 Federal departments and agencies, has been concerned with network robustness since its formation in 1963. The NCS is developing and implementing systems and services that enhance the capability of the public switched networks to support critical Government communication requirements during times of crisis or emergency. Quantitative indicators of network robustness are needed to analyze the benefits of these enhancements. This project proposes a set of candidate capability indicators that could be used by the NCS in future analyses of the public switched networks with and without network enhancements.</p> / Master of Science

The two-phase approach to the problem of reconciling Dominion Bank's FRB account permitted us to satisfy the critical need for improving the manual process, while allowing us to plan a long-term solution. The implementation of the short-term program provided an automated means of keeping track of exception items by allowing the addition and deletion of items in four database files representing "We Debits," We Credits," "FRB Debits, II and "FRB Credits." This eliminated the need to manually transcribe the revised list, initially comprising 1300 items, on a biweekly basis. The migration from a biweekly to a daily reconcilement would have been impossible without the implementation of this program. The short-term program also provided the ability to print reports of exception items in a variety of formats which made it possible to focus on stale items and to report only the relevant items to the originating areas which was made possible by the use of the balancing and report group codes. The balancing phase of the process was also enhanced by the short-term program because it provided the ability to instantaneously calculate net totals of exception items. This feature helped to identify out-of-balance conditions prior to the close of business each day_ The use of the balancing group codes made the balancing process more efficient because out-of-balance conditions could be identified by group, permitting faster resolution of problem conditions. Another feature of the short-term program that enhanced the reconcilement process was the ability to attach descriptive information to the exception items in the database files using a 3D-character description field. Special reports could be generated as needed based on the information in this field, / Master of Science

Master of Science

<p>To fill the need for automated assistance during the system engineering process, a prototype computer-aided tool emphasizing requirements analysis and traceability management is designed and developed. An object-oriented approach is used which leads to the selection of Smalltalk as the implementation language. Peter Chen's Entity-Relationship- Attribute database structure is selected to maintain a complete and consistent system definition. "User-friendly" interfaces are implemented to allow efficient manipulation and representation of the system definition data. These interfaces include a system engineering editor, two engineering views (text and hierarchy), a requirement extractor, and a schema extender. The prototype is expandable and extendable to permit future upgrades to support additional views, reports, and dynamic verification of models. With system definition becoming increasingly important in designing error-free, cost-effective systems, this computer-aided system engineering tool provides an accessible source of automated assistance to support the engineer.</p> / Master of Science

<p>This report identifies the activities of the Peninsula Center (P.C.) located 1n Hampton, Virginia and defines the dynamic system that exists at this facility. It explains the functions and responsibilities of the personnel, and ultimately details the site's activities throughout the semester. This is done in an effort to illustrate the opportunity for improvements in efficiency and enhancement of system capabilities.</p> / Master of Science

The primary purpose of this study was to develop and test a model for the process of making the decision to select/not select cook-chill for hospital food services. A second purpose was to determine the nature of the decision strategy, analytical versus intuitive, most predictive of satisfaction with cook-chill. A generic decision model was developed based on an extensive review of literature on decision making. Due to the lack of research on food service systems, a modified Delphi technique was used to identify 1) the factors critical in the process of making the decision to select/not select cook-chill and 2) the characteristics of a successful hospital cook-chill operation. The information gathered from the Delphi technique was used to develop a questionnaire which would measure the applicability of the generic model to the decision to select/not select cook -chill food production. The generic model was composed of five decision components and one satisfaction component. Using the model as a framework, a questionnaire was developed to test the relationships between the components of the model. Correlations between these components revealed that the use of the model was significantly related with satisfaction with the decision to select/not select cook-chill. A "Checklist for the Process of Making the Decision to SelectINot Select Cookchill Food Production for Hospital Foodservices" was developed using the model and questionnaire as frameworks. The Checklist consists of 136 questions: 101 questions measuring the decision process and 35 questions measuring satisfaction with the decision. For the purposes of this study, analytical decision making was defined as a process where objective, as opposed to subjective information, was available and was used in the process of making the decision. The Checklist consisted of questions to which there was a "yes" or "no" response. The higher the number of "yes" responses on the decision component questions, the more analytical the decision process and the higher the correlation with satisfaction. It was statistically determined that 37 "yes" responses resulted in satisfaction with the decision process. The lower the number of "yes" responses on the decision component questions, the more intuitive the decision process and the lower the correlation with satisfaction. The results of this study are significant in that an extensive review of literature between 1950 and 1990 showed that there was little empirically based research on foodservice systems. The existing research prior to this study did not provide enough information to develop a model for the process of making the decision to select/not select cook-chill production for any foodservice operation. The model developed and tested in this research is generic in nature and should apply equally well in a variety of types of foodservices. It may be necessary to make minor adaptations to the Checklist to address the unique nature of various types of foodservices such as schools, college/universities, military, prisons, hotels, and restaurants. / Ph. D.