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

This qualitative naturalistic research study investigated peer interaction and its relationship to the learning of Logo geometry concepts within an elementary school computer lab classroom environment. The work of four focal children (10-11 years old) and their partners was analyzed. The study looked at (1) the kind of working relationships which existed between the partners, (2) the verbal strategies used by the partners during their mathematics disagreement, and (3) the ways in which the talk between the partners and the strategies they used both contributed to their learning, and reflected their learning, of the geometry concepts (with an emphasis upon the aspect of angular rotation). / The findings revealed that all but one of the dyadic (and triadic) partnerships were collaborative and symmetrical: the children took turns giving information and explanation. At times the information was incorrect. The number of explanations given was very small. A range of peer teaching skills was in evidence. There was no correspondence found between the rate of use of higher level strategies (which included talk supported by reasons), and the child's general Logo achievement. However, the verbal strategies used during disagreements did reveal the children's modes of working and thinking. Seven of the ten children worked in an algorithmic way; the other three seemed to understand what they were doing when they worked with angular rotations. The study was able to report on aspects concerning the children's understanding of angular rotation in the early stages of Logo learning, as well as on the sociocognitive aspect concerning the effects that children working together can have upon their learning of Logo geometry concepts.

No description available.

In existing algorithmic programming languages, algorithms are expressed almost exclusively in the present tense. This thesis examines the feasibility of adding tenses other than the present tense to algorithmic languages. The benefits of such extensions are studied with regard to clarity and succinctness of algorithms, readability of programs and efficiency of implementation. / The specifications are given for T-Pascal, a derivate of Pascal with a past tense, a future tense and a subjunctive. The utility of the additional tenses is illustrated by comparing code of programs in T-Pascal with other standard programming language solutions. The results indicate that the additional tenses are practical enhancements to an algorithmic language. An implementation of a compiler for the new language shows that programs in T-Pascal are in most cases as efficient as program written with the conventional tools of an algorithmic language.

Thesis (PhDInformationTechnology)--University of South Australia, 2004.

Thesis (Ph. D.)--Oregon State University, 1989. / Typescript (photocopy). Includes bibliographical references (leaves 111-141). Also available on the World Wide Web.

Thesis (M.S.)--Rochester Institute of Technology 1987. / Includes bibliographical references (leaves 86-88).

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliography.