The relational model has dominated the database field because of its reduced application development time and non-procedural data manipulation features. It has significant problems, however, including weak integrity constraints. This paper discusses the need for object oriented techniques to improve on these flaws. Three existing DBMS will be discussed: IRIS, ORION, and OZ. / Department of Computer Science

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.

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.C.S.)--Carleton University, 2002. / Includes bibliographical references (p. 104-112). Also available in electronic format on the Internet.

Thesis (M.S.)--Rochester Institute of Technology, 1990. / Includes bibliographical references (leaves [69-71]).

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.

Aplicações ditas não convencionais, como, por exemplo, CAD, CASE, Automação de Escritórios, entre outras, freqüentemente exigem a manutenção de diversos estados da base de dados, retendo o histórico das modificações realizadas. Como resposta a tal requisito, é empregado o conceito de Versão. Neste trabalho o Modelo de Versões proposto por Golendziner é empregado no contexto da evolução de esquemas. Versões são utilizadas para armazenar os diferentes estados do esquema, de suas classes e métodos e, ainda, para posterior adaptação das instancias vigentes no banco de dados, mantendo um histórico da evolução do esquema do banco de dados. É proposto um modelo flexível de suporte a evolução de esquemas em bancos de dados orientados a objetos, bem como estratégias de propagação das instancias vigentes na base de dados. O histórico das modificações é representado pela derivação de versões do esquema e de seus elementos. Os estados anteriores as transformações são preservados, permitindo aos usuários a navegação retroativa e proativa entre versões, para realização de operações consistentes de modificação e consulta. / Non-conventional applications such as CAD, CASE, office automation often require the maintenance of various database states, to keep track of the history of the performed updates. The concept of version is employed to support such requirement. In this work, the version model proposed by Golendziner is used in the schema evolution context. Versions are used to store the different states of the schema, classes and methods, as well as for the mapping of database instances among the various schema versions, thus keeping the history of the database schema evolution. A flexible model is proposed to support schema evolution in object-oriented databases, as well as the strategies to propagate the corresponding changes to the database instances. Versions of schema, as well as versions of the schema elements represent their evolution history. In the proposed model, previous states are preserved allowing the user to make queries about consistency and modifications in both backward and forward version.

Aplicações ditas não convencionais, como, por exemplo, CAD, CASE, Automação de Escritórios, entre outras, freqüentemente exigem a manutenção de diversos estados da base de dados, retendo o histórico das modificações realizadas. Como resposta a tal requisito, é empregado o conceito de Versão. Neste trabalho o Modelo de Versões proposto por Golendziner é empregado no contexto da evolução de esquemas. Versões são utilizadas para armazenar os diferentes estados do esquema, de suas classes e métodos e, ainda, para posterior adaptação das instancias vigentes no banco de dados, mantendo um histórico da evolução do esquema do banco de dados. É proposto um modelo flexível de suporte a evolução de esquemas em bancos de dados orientados a objetos, bem como estratégias de propagação das instancias vigentes na base de dados. O histórico das modificações é representado pela derivação de versões do esquema e de seus elementos. Os estados anteriores as transformações são preservados, permitindo aos usuários a navegação retroativa e proativa entre versões, para realização de operações consistentes de modificação e consulta. / Non-conventional applications such as CAD, CASE, office automation often require the maintenance of various database states, to keep track of the history of the performed updates. The concept of version is employed to support such requirement. In this work, the version model proposed by Golendziner is used in the schema evolution context. Versions are used to store the different states of the schema, classes and methods, as well as for the mapping of database instances among the various schema versions, thus keeping the history of the database schema evolution. A flexible model is proposed to support schema evolution in object-oriented databases, as well as the strategies to propagate the corresponding changes to the database instances. Versions of schema, as well as versions of the schema elements represent their evolution history. In the proposed model, previous states are preserved allowing the user to make queries about consistency and modifications in both backward and forward version.

Aplicações ditas não convencionais, como, por exemplo, CAD, CASE, Automação de Escritórios, entre outras, freqüentemente exigem a manutenção de diversos estados da base de dados, retendo o histórico das modificações realizadas. Como resposta a tal requisito, é empregado o conceito de Versão. Neste trabalho o Modelo de Versões proposto por Golendziner é empregado no contexto da evolução de esquemas. Versões são utilizadas para armazenar os diferentes estados do esquema, de suas classes e métodos e, ainda, para posterior adaptação das instancias vigentes no banco de dados, mantendo um histórico da evolução do esquema do banco de dados. É proposto um modelo flexível de suporte a evolução de esquemas em bancos de dados orientados a objetos, bem como estratégias de propagação das instancias vigentes na base de dados. O histórico das modificações é representado pela derivação de versões do esquema e de seus elementos. Os estados anteriores as transformações são preservados, permitindo aos usuários a navegação retroativa e proativa entre versões, para realização de operações consistentes de modificação e consulta. / Non-conventional applications such as CAD, CASE, office automation often require the maintenance of various database states, to keep track of the history of the performed updates. The concept of version is employed to support such requirement. In this work, the version model proposed by Golendziner is used in the schema evolution context. Versions are used to store the different states of the schema, classes and methods, as well as for the mapping of database instances among the various schema versions, thus keeping the history of the database schema evolution. A flexible model is proposed to support schema evolution in object-oriented databases, as well as the strategies to propagate the corresponding changes to the database instances. Versions of schema, as well as versions of the schema elements represent their evolution history. In the proposed model, previous states are preserved allowing the user to make queries about consistency and modifications in both backward and forward version.