Martin Staudt

ConceptBase—a deductive object base for meta data management

Deductive object bases attempt to combine the advantages of deductive relational databases with those of object-oriented databases. We review modeling and implementation issues encountered during the development of ConceptBase, a prototype deductive object manager supporting the Telos object model. Significant features include: 1) The symmetric treatment of object-oriented, logic-oriented and graph-oriented perspectives, 2) an infinite metaclass hierarchy as a prerequisite for extensibility and schema evolution, 3) a simple yet powerful formal semantics used as the basis for implementation, 4) a client-server architecture supporting collaborative work in a wide-area setting. Several application experiences demonstrate the value of the approach especially in the field of meta data management.

Subsumption between queries to object-oriented databases

Subsumption between queries is a valuable information, e.g., for semantic query optimization. We approach the subsumption problem in the setting of object-oriented databases, and find that reasoning techniques from Artificial Intelligence can be applied and yield efficient algorithms.

Metadata standards for data warehousing: open information model vs. common warehouse metadata

Metadata has been identified as a key success factor in data warehouse projects. It captures all kinds of information necessary to analyse, design, build, use, and interpret the data warehouse contents. In order to spread the use of metadata, enable the interoperability between repositories, and tool integration within data warehousing architectures, a standard for metadata representation and exchange is needed. This paper considers two standards and compares them according to specific areas of interest within data warehousing. Despite their incontestable similarities, there are significant differences between the two standards which would make their unification difficult.

EULE: a knowledge-based system to support business processes

Office tasks related to the processing of contracts in the insurance business are complex and highly dependent on legal and company-specific regulations. Furthermore, due to increasing competition on the market there is a strong pressure to increase the efficiency and quality of office task performance. The only way to meet these manifold requirements is to provide a computer-based guidance and interactive support for office workers. At Swiss Life, we have developed the EULE system that fulfills these requirements. EULEs functionality is in the triangle of Knowledge Representation, Business Process Modeling, and Knowledge Management — the latter because EULE encodes and stores knowledge which is crucial for the company. The system relies on a knowledge representation language which covers data and process aspects as well as the relevant legislation and company regulations.

ConceptBase Managing Conceptual Models about Information Systems

ConceptBase is a meta data management system intended to support the cooperative development and evolution of information systems with multiple interacting formalisms. It supports a simple logic-based core language, O-Telos, which integrates deductive and object-oriented features in order to support the syntactical, graphical, and semantic customization of modeling languages as well as analysis in multi-language modeling environments.

Query by class, rule, and concept

The ideal query language for a knowledge base will probably never be found: easy formulation and easy evaluation of queries are two conflicting goals. Easy formulation asks for a flexible, expressive language near to human language or gestures. Easy evaluation of queries requires an effective mapping to machine code, which computes the correct answer in a finite number of steps. This article approaches the problem by a query language with three faces. The first projects queries to concepts of the knowledge representation language KL-One for easy formulation and readability. The second presents queries as rules of a deductive database with fixpoint semantics. The third presents queries as classes whose instances are the materialized answer (view) to the query. The methods for maintaining and updating the views are compiled from their deductive interpretation.

Organizational Memory Supported Workflow Management

Business processes are by nature information-intensive and require IT support. Database systems solve the basic need for secure and efficient data storage and access. As such they are well-understood and widely applied. Workflow management systems, currently being added to support and optimize formal business processes, distribute jobs among employees. Recently, researchers and practioners started to promote the idea to explicitly represent the knowledge of the enterprise as so-called “Organizational Memory”.

Design and management of data warehouses report on the DMDW'99 workshop

The idea of building data warehouses as central data collections made available for decision support applications in a company is widely accepted. The concrete design and management of a data warehouse from a technical as well as from an organizational point of view, however, turns out to be far from trivial but requires sophisticated and time consuming efforts. The DMDW workshop was held at the CAiSE’99 conference in Heidelberg on June 14-15, 1999. It had the intention to bring together practitioners and researchers to discuss the design and management of data warehouses. The various presentations gave a broad view on the data warehouse life cycle covering aspects relevant at design time, at build time and at run time. Overall, DMDW’99 was recognized as a success. The 30+ participants enjoyed the high quality program (acceptance rate of 50 percent) and had vivid discussions. In this report, we review the presentations given at the DMDW workshop and present some open problems which we believe should be addressed by future research and whose solution could contribute to make data warehouse research more relevant to the practice.

Cooperative support for office work in the insurance business

Office tasks related to processing of contracts in the insurance business are complex and highly dependent on legal and company-specific formal regulations. On the other hand, the increasing competition strongly influences efficiency as well as quality requirements and makes such activities very dealing with critical for the company success. This paper describes the main ideas behind the EULE system implemented at Swiss Life to provide computer based guidance and interactive support for typical office tasks dealing with private life insurance. The system relies on a knowledge representation language which covers data and process aspects including encoding of the relevant regulation contexts. Based on specifications in this language a compiler enables the automatic generation of executable systems. Furthermore, we sketch the embedding of EULE into a general advanced software architecture, in particular w.r.t. organizational memory, functionality workflow management and business process modeling.

A Generic Subsumption Testing Toolkit for Knowledge Based Queries

Subsumption checking is a key technique for intensional reasoning in data and knowledge bases, with applications in terminology management, schema integration, query optimization, reuse of materialized views, and cooperative question-answering. However, the demands of these applications differ, and general solutions covering all these aspects are undecidable or at least computationally intractable. We have therefore implemented a generic approach from which subsumption testers can be configured by tuning certain parameters. Specific contributions include a coverage of negation and the exploitation of semantic knowledge. An application in the ConceptBase system, a deductive object manager for meta data, indicates the practical usefulness of the approach.