Stefan Vieweg

Database Requirements for CIM Applications

Changes in market and production profiles require a more flexible concept in manufacturing. Computer integrated manufacturing (CIM) describes an integrative concept for joining business and manufacturing islands. In this context, database technology is the key technology for implementing the CIM philosophy. However, CIM applications are more complex and thus more demanding than traditional database applications such as business and administrative applications. Systematically analyses the database requirements for CIM applications including business and manufacturing tasks. Special emphasis is given on integration requirements due to the distributed, partly isolated nature of CIM applications developed over the years. An illustrative sampling of current efforts in the database community to meet the challenge of non‐standard applications such as CIM is presented.

KELP: A Hypertext oriented User-Interface for an Intelligent Legal Fulltext Information Retrieval System

This paper concerns the description of K L E P, an intelligent legal information retrieval system with emphasis on a Hypertext oriented presentation of retrieved documents. K L E P provides two distinct categories of descriptors for indexing the documents. An approach to term classification and a four level hierarchy of interdocument similarities is introduced. Cluster analysis based on these similarities and a hierarchy of subject fields provided by a knowledge base is performed to obtain document classification. The retrieved documents are presented in a graphical browsing system showing both similarities between documents and similarities between retrieved documents and query. The relationships obtained from indexing and classification, and the knowledge base are used to obtain automatically generated Hypertext links for a user-friendly presentation of documents.

Active Object-Oriented Database Systems for CIM Applications

Object-oriented database systems (OODBS) have gained wide attention as the most promising database technology for non-standard applications like computer aided design and computer integrated manufacturing. Among the most important requirements of these applications which are supported by OODBS are complex object modeling, advanced transaction management, and version management, to mention just a few. Active database systems (ADBS) have reached equal potential for non-standard applications as they offer event driven and constraint driven behavior of the database system necessary for implementing time critical reactions. For example, manufacturing plants need timely support of raw material and assemblies to keep going the manufacturing process. Active object-oriented database systems (AOODBS) provide the best of both worlds. They are based on one hand on an object-oriented data model for representing the objects of the problem domain, and on the other hand on a rule based knowledge model for representing the event driven and constraint driven behavior. In the first part of this chapter we survey various approaches to AOODBS. In the second part we report on our own experience in extending the commercially available OODBS GemStone™ with active capabilities. TriGS (= Trigger system for GemStone) focuses on several concepts that originate both from shortcomings of existing active object-oriented database systems and from advanced requirements of Leitstand systems, for which TriGS has been developed in the first place. TriGS makes explicit use of objects, message passing, inheritance, and overriding to provide for a seamless integration between rules and an object-oriented data model. Rules consisting of events, conditions, and actions monitor the behavior of objects and can be attached to specific classes (local rules) or defined independently of any class hierarchy (global rules). Concerning the execution of rules, TriGS uses a flexible event based mechanism defining the points in time when conditions are evaluated and actions are executed. An evaluation of TriGS and a discussion of future research issues concludes this chapter.

BRANT — An Approach for Knowledge Based Document Classification in the Information Retrieval Domain

Classical approaches, namely term weighting and statistical document clustering do not score to achieve substantial breakthroughs in information retrieval research. Information retrieval systems must be designed to overcome the syntactical barrier in document representation. This paper discusses the combination of classical term weighting approaches and probabilistic inference concepts to form a powerful semantic document classification model. BRANT is a prototype adapting inference strategies from medical differential diagnosis to the area of information retrieval.

Migration in object-oriented database systems—a practical approach

Object‐oriented database systems are designed to meet the requirements of advanced database applications such as computer‐integrated manufacturing. These requirements may evolve in the course of time and may require the migration of the database application from one object‐oriented database system to another. Traditional migration approaches for relational database systems fail when applied to object‐oriented database systems. The goal of this paper is to fill this gap. The paper describes a framework for the migration of object‐oriented database applications. Our approach is based on a detailed analysis of the involved database systems, of the applications database requirements, and of the resources available for the database migration. We illustrate our framework by means of a case study, which is migrating an electronic planning board system from the object‐oriented database system ONTOS to ObjectStore.

Database Requirements of CIM Applications

Changes in market and production profiles require a more flexible concept of manufacturing. Computer Integrated Manufacturing (CIM) describes an integrative concept for joining business and manufacturing islands. In this context database technology is the key technology for implementing the CIM philosophy. However, CIM applications are more complex and thus, more demanding than traditional database applications like business and administrative applications. In this chapter we systematically analyze the database requirements for CIM applications including business and manufacturing tasks. Special emphasis is given on integration requirements due to the distributed, partly isolated nature of CIM applications developed over the years. An illustrative sampling of current efforts in the database community to meet the challenge of nonstandard applications like CIM concludes this chapter.

Eine Hypertext-Benutzerschnittstelle für ein juristisches Volltext Information Retrieval System

Die vorliegende Arbeit gibt einen kurzen Uberblick uber das EUREKA Projekt 359, „Lokale intelligente Benutzerschnittstelle fur Volltext-Retrieval-systeme (ITS 90)“. Der Projektteil Hypertextschnittstelle fur juristisches Volltext Information Retrieval wird prasentiert. Dabei wir der Benutzerin die Moglichkeit angeboten, ausgehend von Rechtsvorschriftenzitaten in Gerichtsentscheidungen mittels Hypertextfunktionen in eine Rechtsvorschriftendatenbank zu verzweigen. Dadurch erhalt die Benutzerin die Moglichkeit des Zugriffs auf zwei thematisch unterschiedliche Datenbasen. Mittels Hypertextfunktionen konnen somit die rechtlichen Grundlagen von Gerichtsentscheidungen durch direkte Betrachtung die zugrundeliegenden Rechtsvorschriften uberpruft bzw. nachvollzogen werden.