Physical Sciences and Mathematics Commons^™

Effective And Appropriate Use Of Controlled Experimentation In Software Development Research, Mark Alan Johnson

Dissertations and Theses

Although there is a large body of research and publication on software development, only a limited amount of this work includes empirical demonstration of its effectiveness. Yet, it is this empirical understanding which will help move software development from a craft to an engineering discipline. Of the empirical methods for research, controlled experiments are the most commonly thought of in scientific studies, and yet the least used to study software development.

This thesis begins with a brief review of the different empirical methods commonly used to study software development. This review provides a quick introduction to each empirical method, compares …

Needed Narrowing As The Computational Strategy Of Evaluable Functions In An Extension Of Goedel, Bobbi J. Barry

Dissertations and Theses

A programming language that combines the best aspects of both the functional and logic paradigms with a complete evaluation strategy has been a goal of a Portland State University project team for the last several years. I present the third in a series of modifications to the compiler of the logic programming language Goedel which reaches this goal. This enhancement of Goedel's compiler translates user-defined functions in the form of rewrite rules into code that performs evaluation of these functions by the strategy of needed narrowing. In addition, Goedel's mechanism that evaluates predicates is supplemented so that needed narrowing is …

Abstract Index Interfaces, Muralidharan Janakiraman

Dissertations and Theses

An index in a database system interacts with many of the software modules in the system. For systems supporting a wide range of index structures, interfacing the index code with the rest of the system poses a great problem. The problems are an order of magnitude more for adding new access methods to the system. These problems could be reduced manifold if common interfaces could be specified for different access methods. It would be even better, if these interfaces could be made database-system independent. This thesis addresses the problem of defining generic index interfaces for access methods in database systems. …

Contention-Free Scheduling Of Communication Induced By Array Operations On 2d Meshes, Andreas Bernhard Georg Eberhart

Dissertations and Theses

Whole array operations and array section operations are important features of many data-parallel languages. Efficient implementation of these operations on distributed-memory multicomputers is critical to the scalability and high-performance of data-parallel programs. This thesis presents an approach for analyzing communication patterns induced by array operations and for using run-time information to schedule the message flow. The distributed, dynamic scheduling algorithms guarantee link-contention-free data transfer and utilize network resources almost optimally. They incur little overhead, which is important in order not to reduce the speedup gained by the parallel execution. The algorithms can be used by compilers for the generation of …

Compiling Evaluable Functions In The GöDel Programming Language, David Shapiro

Dissertations and Theses

We present an extension of the Gödel logic programming language code generator which compiles user-defined functions. These functions may be used as arguments in predicate or goal clauses. They are defined in extended Gödel as rewrite rules. A translation scheme is introduced to convert function definitions into predicate clauses for compilation. This translation scheme and the compilation of functional arguments both employ leftmost-innermost narrowing. As function declarations are indistinguishable from constructor declarations, a function detection method is implemented.

The ultimate goal of this research is the implementation of extended Gödel using needed narrowing. The work presented here is …

A Policy-Independent Secure X Server, Kirk Joseph Bittler

Dissertations and Theses

This thesis demonstrates that a secure X system can be designed and implemented to be independent of a particular security policy. The advantages and costs of a separation of security policy and enforcement are examined by developing a large scale application, the DX windowing system, on a DTOS platform. DTOS is a high assurance operating system that isolates policy decisions in a Security Server. A security conscious process, such as DX, eliminates policy considerations from the code. The process instead consults the Security Server and enforces the decisions that server derives from the policy. The DX architecture is described and …