Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Thesis. 1976. M.S.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / Microfiche copy available in Archives and Engineering. / Includes bibliographies. / by William J. Masek. / M.S.

Current data flow testing criteria cannot be applied to test array elements for two reasons: 1. The criteria are defined in terms of graph theory which is insufficiently expressive to investigate array elements. 2. Identifying input data which test a specified array element is an unsolvable problem. We solve the first problem by redefining the criteria without graph theory. We address the second problem with the invention of the wp_du method, which is based on Dijkstra's weakest pre-condition formalism. This method accomplishes the following: Given a program, a def-use pair and a variable (which can be an array element), the method computes a logical expression which characterizes all the input data which test that def-use pair with respect to that variable. Further, for any data flow criterion, this method can be used to construct a logical expression which characterizes all test sets which satisfy that data flow criterion. Although the wp_du method cannot avoid unsolvability, it does confine the presence of unsolvability to the final step in constructing a test set.

Parallel processing has gained increasing importance over the last few years. A key aim of parallel processing is to improve the execution times of scientific programs by mapping them to many processors. Loops form an important part of most computational programs and must be processed efficiently to get superior performance in terms of execution times. Important examples of such programs include graphics algorithms, matrix operations (which are used in signal processing and image processing applications), particle simulation, and other scientific applications. Pipelining uses overlapped parallelism to efficiently reduce execution time.

Symbolic execution is a powerful technique used to perform various activities such as program testing, formal verification of programs, etc. However, symbolic execution does not deal with indexed variables in an adequate manner. Integration of indexed variables such as arrays into symbolic execution would increase the generality of this technique. We present an original substitution technique that produces array-term-free constraints as a counterargument to the commonly accepted belief that symbolic execution cannot handle arrays. The substitution technique deals with constraints involving array terms with a single aggregate name, array terms with multiple aggregate names, and nested array terms. Our approach to solving constraints involving array terms is based on the analysis of the relationship between the array subscripts. Dataflow dependence analysis of programs involving indexed variables suffers from problems of undecidability. We propose a separation technique in which the array subscript constraints are separated from the loop path constraints. The separation technique suggests that the problem of establishing data dependencies is not as hard as the general loop problem. In this respect, we present a new general heuristic program analysis technique which is used to preserve the properties of the relations between program variables.

The appropriate separation of concerns is a fundamental engineering principle. A concern, for software developers, is that which must be represented by code in a program; by extension, separation of concerns is the ability to represent a single concern in a single appropriate programming language construct. Advanced separation of concerns is a relatively recent technique in software development for dealing with the complexity of systems that contain crosscutting concerns, namely those individual concerns that cut across programs. Aspect-oriented programming (AOP), which is the area of this dissertation, offers a form of advanced separation of concerns in which primary and crosscutting concerns can be separated during problem solving. An aspect gathers into one place a concern that is or would otherwise be scattered throughout an object-oriented program or system. The primary aim of this dissertation-the AOPy project-is to investigate the usefulness of advanced separation of concerns that aspect-oriented programming offers. In other words, the AOPy Project determines whether the potential usefulness of aspect-oriented programming is currently actualized in practice. In determining its current practical usefulness, this dissertation also determines characteristics of and obstacles to usefulness of aspect-orientation in software development. Perhaps the most important contribution to understanding and addressing the problem of complexity in software systems that this dissertation makes is that the AOPy research project establishes a definition of compatibility of aspect-orientation and provides an analysis of sample instances during problem solving that indicate evidence of compatibility between object-orientation and aspect-orientation. Compatibility, as defined by the AOPy Project, exists when aspect-oriented ideas, terminology, and techniques are appropriately employed in the experimental problem-solving session. The primary scientific contribution of this dissertation, therefore, is a narrative description of the actual use of aspect-oriented programming in a series of controlled, problem-solving scenarios. Theories describing the use of aspect-oriented ideas, terminology, and techniques are generated and refined by means of Grounded Theory, a qualitative data analysis technique. Because this dissertation 1) analytically explores areas of compatibility of aspect-orientation with object-orientation and 2) defines areas of compatibility thwarted in practice, this research project can serve as a foundation for the development of aspect-oriented programming-based design methodologies that encourage compatibility and discourage non-compatibility. Therefore, the AOPy Project establishes a foundation for future research in both its methodology and its results and for future software development in practice. By contributing a definition of aspect-oriented compatibility and a framework within which it can be understood, this dissertation fosters the progression toward a seamless use of aspect-orientation between developer and task. / Graduation date: 2005

M.S. / Computer Science / A general river routing algorithm is described. It is assumed that there is one layer available for routing and the terminals are on the boundaries of an arbitrarily shaped rectilinear routing region. All nets are two terminal nets. No crossover is permitted between nets. A minimum separation must be maintained between wires to prevent design rule violations. The separation and default width for all nets are obtained from a parameter file. A command line option permits the user to change the width. The algorithm assumes no grid on the routing plane. The number of corners in a given route is reduced by flipping corners.

Thesis (Ph. D.)--Open University. BLDSC no. DX179937.

Thesis (Ph. D.)--Florida State University, 2003. / Advisor: Dr. Michael Mascagni, Florida State University, College of Arts and Sciences, Dept. of Computer Science. Title and description from dissertation home page (viewed Apr. 8, 2004). Includes bibliographical references.