Peter J. Barclay

Teallach: a model-based user interface development environment for object databases

Abstract Model-based user interface development environments show promise for improving the productivity of user interface developers, and possibly for improving the quality of developed interfaces. While model-based techniques have previously been applied to the area of database interfaces, they have not been specifically targeted at the important area of object database applications. Such applications make use of models that are semantically richer than their relational counterparts in terms of both data structures and application functionality. In general, model-based techniques have not addressed how the information referenced in such applications is manifested within the described models, and is utilised within the generated interface itself. This lack of experience with such systems has led to many model-based projects providing minimal support for certain features that are essential to such data intensive applications, and has prevented object database interface developers in particular from benefiting from model-based techniques. This paper presents the Teallach model-based user interface development environment for object databases, describing the models it supports, the relationships between these models, the tool used to construct interfaces using the models and the generation of Java programs from the declarative models. Distinctive features of Teallach include comprehensive facilities for linking models, a flexible development method, an open architecture, and the generation of running applications based on the models constructed by designers.

The Teallach tool: using models for flexible user interface design

Model-based user interface development environments aim to provide designers with a more systematic approach to user interface development using a particular design method. This method is realised through tools which support the construction and linkage of the supported models. This paper presents the tools which support the construction of the Teallach models in the context of the Teallach design method. Distinctive features of the Teallach tool include comprehensive facilities for relating the different models, and the provision of a flexible design method in which models can be constructed and related by designers in different orders and in different ways.

Exploiting Model-based Techniques for User Interfaces to Databases

Model-based systems provide methods for supporting the systematic and efficient development of application interfaces. This paper examines how model-based technologies can be exploited to develop user interfaces to databases. To this end five model-based systems, namely Adept, HUMANOID, Mastermind, TADEUS and DRIVE are discussed through the use of a unifying case study which allows the examination of the approaches followed by the different systems.

A framework for information visualisation

In this paper we examine the issues involved in developing information visualisation systems and present a framework for their construction. The framework addresses the components which must be considered in providing effective visualisations. The framework is specified using a declarative object oriented language; the resulting object model may be mapped to a variety of graphical user interface development platforms. This provides general support to developers of visualisation systems. A prototype system exists which allows the investigation of alternative visualisations for a range of data sources.

A framework for user-interfaces to databases

A framework for user-interfaces to databases (IDSs) is proposed which draws from existing research on human computer interaction (HCI) and database systems. The framework is described in terms of a classification of the characteristic components of an IDS. These components, when progressively refined, may be mapped to a conceptual object-oriented language for the precise specification of the IDS. A prototype system is presented, showing the potential for automated mapping of a language specification to a fully functional implementation. As well as providing general support to any database interface developer, we believe that the framework will prove useful for researching a number of IDS issues.

Using a Metadata Software Layer in Information Systems Integration

A Federated Information System requires that multiple (often heterogenous) information systems are integrated to an extent that they can share data. This shared data often takes the form of a federated schema, which is a global view of data taken from distributed sources. One of the issues faced in the engineering of a federated schema is the continuous need to extract metadata from cooperating systems. Where cooperating systems employ an object-oriented common model to interact with each other, this requirement can become a problem due to the type and complexity of metadata queries. In this research, we specified and implemented a metadata software layer in the form of a high-level query interface for the ODMG schema repository, in order to simplify the task of integration system engineers. Two clears benefits have emerged: the reduced complexity of metadata queries during system integration (and federated schema construction) and a reduced learning curve for programmers who need to use the ODMG schema repository.

Teallach — a flexible user-interface development environment for object database applications

The Teallach project has adapted model-based user-interface development techniques to the systematic creation of user-interfaces for object-oriented database applications. Model-based approaches aim to provide designers with a more principled approach to user-interface development using a variety of underlying models, and tools which manipulate these models. Here we present the results of the Teallach project, describing the tools developed and the flexible design method supported. Distinctive features of the Teallach system include provision of database-specific constructs, comprehensive facilities for relating the different models, and support for a flexible design method in which models can be constructed and related by designers in different orders and in different ways, to suit their particular design rationales. The system then creates the desired user-interface as an independent, fully functional Java application, with automatically generated help facilities.

Using a genetic algorithm for optimizing fixed polarity Reed-Muller expansions of boolean functions

Abstract The use of a genetic algorithm is presented which determines good sub-optimum fixed polarity Reed-Muller expansions of completely specified boolean functions. The algorithm performs better than previous techniques which find a good fixed polarity by non-exhaustive search.

The Prometheus taxonomic database

M.R. Pullen et al. (2000) have designed a new model of plant taxonomy (called Prometheus); it supports multiple overlapping classifications, and distinguishes the process of naming from classifying. The concepts identified in this taxonomic model necessitated the design of a new database model - the Prometheus Object-Oriented Model (POOM) - to represent and manipulate the data. POOM is an extended object-oriented model which emphasises relationships, thereby providing graph behaviour in an object-oriented database and providing an expressive means of defining relationships between objects. Additionally, the Object Query Language (OQL) is extended to the Prometheus Object-Oriented Language (POOL) in order to provide unified querying of object-oriented graph structures. This paper presents a taxonomic database system designed in terms of the concepts offered by POOM. Through examples we show how the representation of the semantics and processes of taxonomy, not possible using existing data models, can be supported. Example POOL queries highlight the need for the extended features for manipulating relationships, graph structures and complex objects such as are found in taxonomies.

Implementation of the Prometheus Taxonomic Model: a comparison of database models and query languages and an introduction to the Prometheus Object-Oriented Model

Types of databases commonly used for handling taxonomic data are compared. It is shown that none of the existing types of databases fully support the requirements of taxonomic data. The results of this comparison provide a rationale for the design and implementation of a new database system based on an Extended Object- Oriented model. The new model, the Prometheus Object-Oriented Model (POOM) and its query language Prometheus Object-Oriented Language (POOL), are discussed in relation to the requirements of taxonomic data and the Prometheus Taxonomic Data Model. POOM provides the ability to represent the semantics of relationships between data. This allows us to build the type of graph structures that are found in taxonomic hierarchies. In addition, the system can query and manipulate these graphs (POOL). These features have been used to improve the original Prometheus Taxonomic Data Model. These improvements and the advantages they offer are described and discussed.