Change is inevitable and unending in developing large, complex systems. Changes to requirements arise not only from changes in the social context of the system, but also from improved understanding of constraints and tradeoffs as system development proceeds. How to trace software requirements is the problem addressed by this thesis. We present a solution for requirements tracing in the context of object-oriented software development. Our solution consists of a traceability model and a tool to automate the tracing. TOOR, the tool to implement the model, uses a project specification written in FOOPS, a general purpose object-oriented language with specification capabilities, to set up the environment in which a project is carried out. The project specification defines the trace units and traces as objects and relations, respectively. The evolution of objects from requirements sources to requirements to design to code, and generally to any object taking part in the process is dealt with in a uniform way in TOOR: classes are declared for each kind of object we wish to control, and relations are defined between them. TOOR uses regular expressions to provide a selective tracing mode: the actual configuration of objects and relations is considered as a text and regular expressions are used to retrieve parts of the configuration matching the pattern described by them. TOOR enhances the flexibility of regular expressions by extending the pattern matching procedure by providing different ways of specifying how an object or relation is to be matched. Other modes of tracing in TOOR are the interactive tracing through modules and the non-guided tracing through several browsing mechanisms. TOOR modules are used to structure projects by providing hierarchical scopes for objects used in a project development. The tracing mechanisms of TOOR can use the project structure to order searches or to provide boundaries for searching. Browsing objects provides additional flexibility in situations where little information of what has to be traced is possessed and hyper-media features address the need to re-interpret data usually encoded in different formats. The user-definable features of a project specification provides much of the flexibility necessary for effective use of a software tracing tool. Also, the integration of regular expression tracing with other forms of tracing such as browsing and interactive tracing makes TOOK an extremely versatile tool. The user can select the more appropriate form of tracing depending on context and can switch from one form to another as convenient.

The object-oriented community is paying increasing attention to techniques for object instance encapsulation and alias protection. Formal techniques for modular verification of programs at the level of objects are being developed hand in hand with type systems and static analysis techniques for restricting the structure of runtime object graphs. Ownership type systems have provided a sound basis for such structural restrictions by being able to statically represent an extensible object ownership hierarchy. However, such structural restrictions may potentially have limitations on cases when more flexible reference structures are desired. In this thesis, we present a different encapsulation technique, called Effect Encapsulation, which confines side effects rather than object references. With relaxed restriction on reference structure, it is able to express certain common object-oriented patterns which cannot be expressed in Ownership Types. From this basis, we also describe a model of Object Validity --- a framework for reasoning about object invariants. Such a framework can track the effect and dependency of method calls on object invariants within an ownership-based type system, even in the presence of re-entrant calls. Moreover, we present an access control technique for protecting object instances. Combined with context variance, the resulting type system allows for a more flexible and useful access control policy, hence is capable of expressing more object-oriented patterns.

Bibliography: leaves 173-179. / xi, 221 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis aims to develop a basic object-oriented data structure and tools for the modelling and simulation of chemical and biochemical processes. The numerical methods are based on the Newton and Gear's Backward Difference methods. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1997

Thesis (M.App.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 141-149). Also available in electronic format on the Internet.

Thesis (M.S.)--Kutztown University of Pennsylvania, 1999. / Source: Masters Abstracts International, Volume: 45-06, page: 3192. Typescript. Abstract precedes thesis as preliminary leaf. Includes bibliographical references (leaves 73-74).

"Revised and summarized version of (the author's) doctoral thesis submitted to the Department of Geography at the University of Edinburgh"--P. xii. / Includes bibliographical references (p. 107-113) and index.

Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 128-131). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Most common object models of distributed object systems have a limited set of object-oriented features, lacking the advanced features of `polymorphism' (an abstraction mechanism that represents a quality or state of being able to assume different forms) and `concurrency' (the ability to have more than one thread of execution in an object simultaneously). The lack of support for advanced features is a serious limitation because it restricts the development of new components and limits reuse of existing of components that use these advanced features. As a result, wrappers must be used that hide the advanced features or components must be re-implemented using only the features of the common object model. In this dissertation, a new direction of research centered on a subset of object-oriented languages, specifically statically typed languages, is considered. One of the major drawbacks of existing distributed object systems is that they cater to a broad domain of programming languages including both object-oriented as well as non object-oriented languages. Mapping an object model into a non object-oriented language is a complex task and it does not appear natural to a native language user. The interoperable common object model (ICOM) proposed in this dissertation is an attempt to elevate common object models (with the advanced features of polymorphism and concurrency) closer to the object models of statically typed object-oriented languages. Specific features of the ICOM object model include: remote inheritance, method overloading, parameterized types, and guard methods. The actor model and reflection techniques are used to develop a uniform implementation framework for the ICOM object model in C++ and Modula-3. Prototype applications were implemented to demonstrate the utility of the advanced features of the ICOM object model. The main contributions of this dissertation are: design and implementation of a powerful common object model, an architecture for distributed compilation, and an implementation of a distributed object model using the actor model. / Ph. D.

Relational databases have proved inadequate for supporting new classes of applications, and as a consequence, a number of new approaches have been taken (Blaha 1998), (Harrington 2000). The most salient alternatives are denormalisation and conversion to an object-oriented database (Douglas 1997). Denormalisation can provide better performance but has deficiencies with respect to data modelling. Object-oriented databases can provide increased performance efficiency but without the deficiencies in data modelling (Blaha 2000). Although there have been various benchmark tests reported, none of these tests have compared normalised, object oriented and de-normalised databases. This research shows that a non-normalised database for data containing type code complexity would be normalised in the process of conversion to an objectoriented database. This helps to correct badly organised data and so gives the performance benefits of de-normalisation while improving data modelling. The costs of conversion from relational databases to object oriented databases were also examined. Costs were based on published benchmark tests, a benchmark carried out during this study and case studies. The benchmark tests were based on an engineering database benchmark. Engineering problems such as computer-aided design and manufacturing have much to gain from conversion to object-oriented databases. Costs were calculated for coding and development, and also for operation. It was found that conversion to an object-oriented database was not usually cost effective as many of the performance benefits could be achieved by the far cheaper process of de-normalisation, or by using the performance improving facilities provided by many relational database systems such as indexing or partitioning or by simply upgrading the system hardware. It is concluded therefore that while object oriented databases are a better alternative for databases built from scratch, the conversion of a legacy relational database to an object oriented database is not necessarily cost effective.