Thesis (M.S. in Computer Science)--Naval Postgraduate School, June 1990. / Thesis Advisor(s): Wu, C. Thomas. Second Reader: Lum, Vincent Y. "June 1990." Description based on signature page. DTIC Identifier(s): Software engineering, event driven multimedia database, acoustic database. Author(s) subject terms: Software engineering, event driven multimedia database, acoustic database. Includes bibliographical references (p. 96). Also available online.

Higher-order transformations are ubiquitous within data management. In relational databases, higher-order queries appear in numerous aspects including query rewriting and query specification. In XML databases, higher-order functions are natural due to the close connection of XML query languages with functional programming. The thesis investigates higher-order query languages that combine higher- order transformations with ordinary database query languages. We de- fine higher-order query languages based on Relational Algebra, Monad Algebra, and XQuery. The thesis also studies basic problems for these query languages including evaluation, containment, and type inference. We show that even though evaluating these higher-order query languages is non-elementary, there are subclasses that are polynomially reducible to evaluation for ordinary query languages. Our theoretical analysis is complemented by an implementation of the languages, our Higher-Order Mapping Evaluation System (HOMES). The system integrates querying and query transformation in a single higher- order query language. It allows users to write queries that integrate and combine query transformations. The system is implemented on top of traditional database management systems. The evaluation algorithm is optimized by a combination of subquery caching techniques from relational and XML databases and sharing detection schemes from functional programming.

Approved for public release, distribution unlimited / The maintenance of large military software systems is complex, involves users as well as software professionals, and requires appropriate management, which is one of the most important factors in efficient maintenance. Maintenance management requires information about the current state of the maintenance process that should be organized within a maintenance-oriented Enginering Database. This database should include all the necessary data about software changes, system configeration, maintenance task scheduling, etc., and it should be based on a realistic model of the maintenance process. This tesis proposes a mathematical Model of Software Maintenance that uses graphs to model the relationships between maintenance tasks and software components. The Model addresses the dynamic behavior of the maintenance process and supports priority and precedence of maintenance activities. The proposed Model of Software Maintenance provides a sound basis for implementation of a maintenance-oriented engineering database that supports automation of maintenance management, e.g., process control, task scheduling, job assignments, planning and forecast, gathering and interpretation of maintenance statistics and metrics, etc.

Vast amounts of evolving data are created in the design of hard real-time software systems. This data must be managed so that it can be stored and retrieved according to the needs of design engineers. In the Computer-Aided Prototyping System (CAPS), a Design Database (DDB) must manage the storage and retrieval of the entire Prototype System Description Language (PSDL) program. This thesis presents a conceptual design and initial implementation of a Design Database (DDB) for the Computer-Aided Prototyping System (CAPS).

In this diploma thesis, I conduct a research into approaches to consolidating data base and source code base of the Techno.cz webserver, which is the subject of the consolidation. By consolidation I mean bringing the server into the state where documentation is produced according to given requirements, data base is changed in order to improve data structure and consistency and source code base is reorganised in order to unify source code upon one platform, improve file system organization and remove problematic characteristics of the source code in general. The goals of this thesis are to create and describe general process of consolidation, sequence and contents of its steps; to describe contents of consolidation in given areas: documentation, data base and source code base; to describe actual steps made to achieve the final state of the server. My approach to accomplishing these goals is the study of relevant literature and usage of my practical experience in the field of web development. My contribution to the topic is the creation of the general consolidation process that has a potential to be reused by similar projects. Another contribution may be the description of handling the risks and problems that emerged during the consolidation process. This topic may find itself as a valuable source of knowledge for fellow developers facing similar issues. The thesis is divided into eight chapters. After the introduction chapter 2 follows. Chapter 2 describes parameters of the Techno.cz webserver. Chapter 3 discusses software engineering methodologies in order to create suitable consolidation process. Chapter 4, 5, 6 discuss particular fields of consolidation: documentation, data base and source code. In chapter 7 I am trying to assess suitability of created processes and approaches for usage in future development. In the conclusion I summarize the thesis according to required structure.

Entity Relationship (ER) diagrams are among the most popular formalisms for the support of database design [7, 12, 17, 6]. Their classical use in the (usually computer aided) database design process can roughly be described as follows: after evaluating the requirements of the application, the database designer constructs an ER schema, which represents the conceptual model of the new database. CASE tools can be used to automatically transform the ER schema into a relational database schema, which is then manually fine-tuned. During the last years, the initially rather simple ER formalisms has been extended by various means of expressivity to account for new, more complex application areas such as schema integration for data warehouses [12, 3, 13]. Designing a conceptual model with such enriched ER diagrams is a nontrivial task: there exist complex interactions between the various means of expressivity, which quite often result in unnoticed inconsistencies in the ER schemas and in implicit ramifications of the modeling that have not been intended by the designer. To address this problem, Description Logics (DLs) have been proposed and succesfully used as a tool for reasoning about ER diagrams and thereby detecting the aforementioned anomalies [5, 6, 8].