Wolfgang Wilkes

A transaction model supporting complex applications in integrated information systems

The use of database systems in new applications, e.g. computer aided design, software engineering, etc, leads to new requirements for the transaction management. Main characteristics of such environments are long duration of transactions and teamwork. In this paper we introduce a concept for lang transactions which especially supports the cooperative work of groups on a common set of data. The transaction model has two levels: on the one hand the team has to be protected from the outside world, on the other hand mechanisms are required which allow controlled teamwork an common objects. In the latter case rigid synchronisation mechanisms as used in database systems are not applicable. A main concept for the support of teamwork and for design databases in general is a user-oriented version mechanism. This paper presents such a mechanism and its integration into the transaction model.

Complex and composite objects in CAD/CAM databases

It is shown that the concept of interfaces and the concept of composite objects are based on the same mechanism, an instance inheritance relationship. This relationship is integrated into an object-oriented data model which represents interfaces and composite objects in an easy way. The concept of interfaces is generalized to an abstraction mechanism. This allows some severe drawbacks of a rigid interface concept to be eliminated and generic component relationships to be needed.<<ETX>>

OOPS-an object oriented programming system with integrated data management facility

OOPS is an object-oriented programming environment with integrated data management facilities. It is designed to especially support advanced applications, like engineering and office applications. Rich data modeling facilities, including the concepts of classification, generalization, and aggregation are provided. Additionally, complex semantic integrity constraints, exception-handling mechanisms, and triggers can be specified. Since all these facilities are integrated into a single language, the artificial distinction between database language and programming language is no longer existent. The main features of the programming language and the architecture of OOPS are presented.<<ETX>>

Information modelling of folded and unfolded design

An information model for a folded design description which corresponds to electronic design interchange format (EDIF) version 2.0.0, using the language Express, is presented. It is shown that it can be easily extended to a model for an unfolded description. A method to compute the actual values for occurrences of views, nets, and ports, is given, which is based on the back-annotation facilities of EDIF and may help to uncover EDIFs underlying semantics.<<ETX>>

HANDICAP - A System for Design Consulting*

CAD frameworks allow to integrate various CAD tools into an integrated design environment. Such a design environment will give the designer more freedom in organizing his design process and he may follow more than only one predefined design path. This paper introduces a design consulting system which supports the designer in performing this additional task of organizing his design process. The system follows a distributed approach: several expert systems evaluate a given design situation on the basis of their local knowledge, and their results are combined into a common proposal as to how to perform the next design steps. The paper describes the underlying concepts and the implementation design of the design consultant prototype HANDICAP.<<ETX>>

Ein Transaktionskonzept zur Unterstützung komplexer Anwendungen in integrierten Systemen

The use of database systems in new applications, e.g. computer aided design, software engineering, etc, leads to new requirements for the transaction management. Main characteristics of such environments are long duration of transactions and teamwork.

A knowledge-based design consultant: model and architecture

Future CAD frameworks for VLSI chip design will provide a component to support the designer in finding applicable design strategies and tools and in deciding which of them are best suited for the specific design task. This paper describes the underlying concepts of a prototype of such a design consulting system. It introduces a model of the design process, which allows one to define where in the design process design consulting can take place and which kind of information should be taken into account to support the designer in making an appropriate decision. The design consulting problem is tackled from an AI point of view: the decision problem is put into a general problem taxonomy and the resulting problem subtypes and solving methods are discussed. Finally, the paper concludes with the description of the architecture of the design consulting system which is based on two blackboards: a control blackboard and a design data blackboard.<<ETX>>

Design of a tool interface for integrated CAD-environments

The tool interface which provides mechanisms for tools to implement their data handling facilities on the basis of a common data schema is a key element of a CAD framework. A tool interface which has been developed and implemented in the DASSY project is described. It decouples the CAD tools from the underlying database, and the chosen architecture with an integrated main memory database allows the adaptation of the tool interface to different databases.<<ETX>>

Technische Informationssysteme zur Unterstützung von Entwurfsprozessen

Die drei Haupt-Arbeitsschritte des GI-Arbeitskreises „Technische Informationssysteme“ in der Fachgruppe 4.2.1. „Rechnerunterstutztes Entwerfen und Konstruieren (CAD)“ der Gesellschaft fur Informatik sind (1) die Aufnahme der Istsituation, (2) die Problemanalyse und (3) die Erarbeitung eines Sollkonzepts. Insgesamt ist ein zentraler und grundlegender Bruch und eine grose Lucke zwischen den prinzipiellen Aufgaben und Zielen von technischen Informationssystemen und der bestehenden Istsituation zu erkennen. Es werden die ersten Ansatze fur das zu erarbeitende Sollkonzept vorgestellt. Vorangestellt ist eine Gegenstandsbestimmung fur das Umfeld des Entwurfs, die fur die Definition und Abgrenzung der Funktionalitat von technischen Informationssystemen notwendig ist.