The Virtual Network (VN) protocol is a communications protocol software compatible with the Space Plug-and-play Architecture (SPA). This Master Thesis defines a protocol that extends the Virtual Network protocol to cover communication over the Controller Area Network (CAN). The Virtual Network for the Controller Area Network (VN-CAN) is defined, modelled and verified using UPPAAL as well as implemented and tested while running on actual hardware. The VN-CAN protocol enables components on the CAN network to communicate with other components both inside and outside of the CAN network, which together with the modularity of both the protocol and the implementation enables application level software to be agnostic of their physical position in the network. The implementation enables components to automatically discover routes to other components on the VN network without the need for any prior knowledge about the network topology. A method for direct addressing, i.e. that two components on the CAN network can communicate directly without sending messages via a central router, has been added to the VN-CAN protocol in order to reduce traffic on the CAN network. UPPAAL modelling and verification of the VN-CAN protocol has been done to give a high level of confidence in the correctness of the protocol. Testing on actual hardware has shown that the protocol achieves the goals of address resolution, self addressing and transfer of VN messages over CAN.

Communication and networking are vast areas which are developing rapidly. It is very important to know in detail how the system works, how it can be enhanced to meet today's requirement, how to implement the appropriate techniques to obtain desired results etc. To explain all of the above, simulation techniques were adopted. Simulation plays an important role in developming new designs and modifying existing systems to make them more feasible and efficient.Protocols are the back bones of the communication systems and play a major role in data transfer. The review of literature provides an explanation of ISO/OSI models, layered approach and concepts of simulation. The simulation was carried out to explain the concepts of error detection, error correction and flow control in Data Link layer. Ada was used to develop the software, because of its concurrent processing tools called tasks. Also state-of-the-art utilities like Vax/Vms Screen Management System, File Definition Language, and Debugger were us ed in the program development. / Department of Computer Science

The solar concentration performance of a tracking, flat-base, line-focusing Fresnel mirror was investigated in this study. The Fresnel mirror consists of flat mirror strips situated on a base and oriented at appropriate angles to focus incident light to a desired line. Simple optical ray tracing and energy conservation were used to develop a mathematical model of the concentrator assuming small or zero diurnal tracking errors. The model analyzed the concentrator design and provided detailed expressions for the geometric evaluation of the concentrated sunlight rays in the focal plane above the mirror. The local concentration ratio and the geometric concentration ratio were introduced to describe the intensity profile in the focal plane and the average concentration of sunlight on a target absorber. Included in the model were losses of incident sunlight due to imperfect reflection, nonreflecting portions of the base, and blockage by adjacent mirror strips when imperfect tracking occurs.Based on the analytical model and using the Ada high level language, a computer program was written to simulate the concentrator. To facilitate performance comparisons, a baseline concentrator design was adopted. To study the effects of imperfect tracking, performance data were generated for small tracking errors up to approximately two and one-half degrees. The effects of design variations were studied by varying the concentrator focal length, strip width, and base width.Simulation results demonstrated that the concentration characteristics were highly sensitive to tracking error. Intensity profile shifts relative to the target caused the highest losses in intercepted sunlight.Design decisions were found to dramatically affect the concentration character- istics. For the baseline concentrator under perfect tracking conditions, an optimum focal length was identified. Except for the disadvantage of added costs, decreased strip widths was found to be a way to increase both the maximum and average concentration ratio for the absorber. Using smaller strip widths might, however, critically affect the energy intercepted by the target under imperfect tracking. Increasing the concentrator base width increased the total amount of power in the focal plane, with a higher maximum concentration ratio and additional tailing of the intensity profile. / Department of Physics and Astronomy

Concurrent processing has always been a traditional problem in developing operating systems. Today, concurrent algorithms occur in many application areas such as science and engineering, artificial intelligence, business systems databases, and many more. The presence of concurrent processing facilities allows the natural expression of these algorithms as concurrent programs. This is a very distinct advantage if the underlying computer offers parallelism. On the other hand, the lack of concurrent processing facilities forces these algorithms to be written as sequential programs, thus, destroying the structure of the algorithms and making them hard to understand and analyze.The first major programming language that offers high-level concurrent processing facilities is Ada. Ada is a complex, general purpose programming language that provides an excellent concurrent programming facility called task that is based on rendezvous concept. In this study, concurrent processing is practiced by simulating a business system using Ada language and its facilities.A warehouse (the business system) consists of a number of employees purchases microwave ovens from various vendors and distributes them to several retailers. Simulation of activities in the system is carried over by assigning each employee to a specific task and all tasks run simultaneously. The programs. written for this business system produce transactions and financial statements of a typical business day. They(programs) are also examining the behavior of activities that occur simultaneously. The end results show that concurrency and Ada work efficiently and effectively. / Department of Computer Science

The Republic of Guinea is located on the west coast of Africa at about 11° North latitude. A large portion of Guinea's supply of protein is dried fish. The actual drying method operates under open air, the foodstuff being unprotected from unexpected rains, windborne dirt and dust, and from infestation by insects, rodents, and other animals. More, the deforestation rate is increasing year after year, depleting the source of fuel for drying. Practical ways of drying fish cheaply and sanitarily would be welcome.Recently, much work has been devoted to developing algorithms for parallel processors. Parallel algorithms have received a great deal of attention because of the advances in computer hardware technology. These parallel processors and algorithms have been used to improve computational speed, especially in the areas of sorting, evaluation of polynomials, arithmetic expressions, matrix and graphic problems.Sorting is an important operation in business and computer engineering applications. The literature contains many sorting algorithms, both sequential and parallel, which have been developed and used in practical applications. bubble sort, quick sort, insertion sort, enumeration sort, bucket and odd-even transposition sort. Ada, a new excellent programming language that offers high-level concurrent processing facilities called tasks, is used in this thesis to introduce, implement, compare and evaluate some of the parallel sorting algorithms. This thesis will also show that parallel sorting algorithms reduce the time requirement to perform the tasks. / Department of Computer Science

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 171-172). Also available via the Internet.

Thesis (M.S.)--Kutztown University of Pennsylvania, 1991. / Source: Masters Abstracts International, Volume: 45-06, page: 3190. Abstract precedes thesis as [1] preliminary leaf. Typescript. Includes bibliographical references (leaf 54).

Thesis (M.A.)--Catholic Theological Union at Chicago, 2005. / Vita. Includes bibliographical references (leaves 110-114).

Stuttgart, Univ., Studienarb., 2003.

Thesis (M.A.)--Catholic Theological Union at Chicago, 2005. / Vita. Includes bibliographical references (leaves 110-114).