Approved for public release; distribution is unlimited / As demand for hard real-time and embedded computer systems increases, a new approach to software development is critical. Software engineers and users would benefit from an automated methodology allowing validation of design specifications or functional requirements early in the development life cycle. A fast, efficient, easy-to-use tool would increase productivity and would enhance user confidence that software would be delivered at less cost and on schedule. The Computer Aided Prototyping System (CAPS) is a conceptualized tool providing these capabilities. This thesis represents a pioneering effort to develop a Static Scheduler for the CAPS Execution Support System using the Ada programming language. The Static Scheduler initially extracts critical operators, timing constraints and precedence relationships from a high-level prototype source program. The Static Scheduler then creates a static schedule for run-time execution, using worst case scenarios, guaranteeing that timing constraints are met. The primary goal of this thesis is to provide the scheduling algorithms and implementation guidelines for the Static Scheduler. Secondary goals are to demonstrate the significance of continued research to telecommunications applications and to demonstrate the feasibility of Ada as the implementation language. / http://archive.org/details/staticschedulerf00jans / Lieutenant, United States Navy

No description available.

Le succès des intergiciels dans le cadre du développement de systèmes d'information ``généralistes'' comme les applications Web, encourage leur utilisation pour le développement d'autres applications plus spécifiques et plus exigentes en qualité de service , comme les applications temps réel ou même certaines applications critiques. Nous partons d'une architecture intergicielle dite schizophrène ayant des propriétés de généricité et de configuration. Cette architecture est renforcée pour supporter deux catégories de services pour la tolérance aux fautes et le consensus. La conservation des propriétés de l'architecture de base ainsi que le respect des contraintes posées par les applications critiques et sûres de fonctionnement sont les principaux objectifs de nos propositions. Les principes et les propriétés de l'architecture schizophrène sont détaillés. Ensuite, nous menons des études approfondies de la théorie de la tolérance aux fautes et du consensus ainsi que de la norme FT CORBA. Ces études nous permettent de généraliser les différents concepts et d'isoler les différentes abstractions utiles afin de proposer deux architectures pour un service de tolérance aux fautes compatible avec la norme FT CORBA et pour un service générique de consensus. Nous montrons que la conception de ces services maximise leur configurabilité. Après les propositions d'architectures, nous décrivons la réalisation effective de ces deux services. Nous nous basons sur PolyORB, un integriciel développé à l'ENST. Des scénarios de test et des mesures de performances complètent notre étude et valident nos propositions.

<p>Syftet med den här rapporten är att undersöka om det finns något testverktyg som uppfyller kraven från Saab Underwater Systems. I rapporten presenteras även en sammanfattning av testningens grunder och metoder för att välja ut och utvärdera datorprogram. Arbetet med att välja ut och utvärdera testverktyg kan ses som en process. Först ska kraven sammanställas och sedan ska några verktyg väljas ut för utvärdering. Två av de tre verktyg som valdes ut utvärderades mer</p><p>ingående. De två testverktyg som utvärderades var LDRA Testbed och AdaTEST 95. LDRA Testbed har väldigt många olika statiska analyser vilket i många fall troligen inte kommer att utnyttjas. Enhetstestningen sker med hjälp av TBrun som är en del av verktygsserien som LDRA marknadsför. AdaTEST 95 har inte lika många funktioner som LDRA Testbed men har de nödvändiga statiska analyserna och enhetstestning presenterade i ett enklare gränssnitt. Båda</p><p>verktygen uppfyller de viktigaste kraven från Saab Underwater Systems, men inget av dem uppfyller alla krav. Båda verktygen skulle kunna underlätta testningen men AdaTEST 95 rekommenderas. AdaTEST 95 är framtaget för att underlätta för i första hand utvecklare och det är utvecklare som ska använda verktyget på Saab Underwater Systems.</p>

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In recent years, the field of distributed processing, distributed systems, has undergone great change, and has been an area attracting tremendous research and development efforts. This thesis explores the various current methodologies for designing, developing and implementing distributed systems using the Ada programming language, and goes on to implement a simulation of a distributed store system using the "virtual node" design approach. After a brief introduction on distributed systems in general, an investigation of the basic issues and problems involved in distributing Ada programs coupled with an analysis and comparison of various approaches to developing distributed Ada systems is carried out. It is shown that one of the critical problems of Ada in a distributed environment is its implicit assumption of a single memory processor. A simulation of a distributed system (store system) is carried out using the virtual node method of developing distributed Ada systems. The various stages of this design method including interface task specification are stepped through. A sample run of the. system is given, including the customer file, stock file data and the monitored output of the system. / Department of Computer Science

From the smallest microcomputer to the largest mainframe computer, data communication capabilities are and will be a major factor in the success and usefulness of the computer systems. The need for larger systems to process data created on the small computers, the need to move subsets of data to small computers access larger computers for other capabilities, and the need for growth in hardware capability are all major reasons that data communication is so important to today's technology.As data communication is the backbone of today's technology, it will play a leading role in governing the changes in the technology of the future. Hence the knowledge of data communication becomes a very important aspect.In this thesis emphasis has been given to simulate the lower layers of communication protocols using Ada as the base language. The language Ada is chosen because of it's capability of providing parallel processing, which is an inherent property of the data communication. Ada is a complex, general purpose programming language that provides an excellent concurrent programing facility called task, that is based on rendezvous concept.Simulation is an excellent way to teach & understand concepts, which otherwise becomes infeasible to understand. Now a days more and more communication details is embedded in the hardware, and hence what is going inside the computer, to provide communication between two computers or just plain data communication, is becoming transparent to the user. However, this does not eliminate the need to know about the functional characteristics of the protocols, which are the rules to provide an effective and reliable communication environment, rather the need to understand protocols is increasing as more and more computer vendors are coming out with their own products. Thanks to the ISO (International Standard Organization), which has come with the standard for the Computer to Computer Communication, but still protocol analysis and design will play a very important role. The field of protocol conversion has grown tremendously in order to provide communication across heterogeneous systems using message communication will to the field of protocol which now a days is an different protocols.Here in this study, communication backbone is simulated in Ada using its concurrent processing capabilities and it is tried to show how a data or aMessage communication will actually take place. This study can serve as a blue print to improve this in order to cater to the field of protocol analysis and protocol conversion, which now a days is an important facet of the data communication industry. / Department of Computer Science

Solar concentrating systems are often used to decrease the cost of solar energy by redirecting the incident sunlight from a relatively large area onto a photovoltaic cell of smaller area. In addition to the convergence characteristics of the concentrator, indices of refraction and reflectivities which are functions of wavelength can result in an illumination which varies both spatially and spectrally on the solar cell. Nonuniformity can also be induced by concentrator tracking error. The effects of such nonuniform illumination on solar cell performance are of interest.In this investigation, a model of a concentrator solar cell consisting of a network of preexisting one-dimensional models has been developed. This model is analyzed for three sample grid configurations for both spot-focusing and line-focusing concentrator applications.Ada computer programs have been created which, together with a few other pieces of readily available software, are capable of simulating the model. Sample simulations have been performed for line-focusing concentrator applications. These results are presented and discussed. / Department of Physics and Astronomy

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 116-118). Also available via the Internet.

Thesis (Ph.D.)--Memorial University of Newfoundland, 2002. / Restricted until May 2003. Bibliography: leaves 317-338.