Paul ten Hagen

Knowledge engineering in design

The authors present, in a unifying framework, the principles of the IIICAD system, a generic design apprentice currently under development at CWI. IIICAD incorporates three kinds of design knowledge. First, it has general knowledge about the stepwise nature of design based on a set-theoretic design theory. Second, it has domain-dependent knowledge belonging to the specific design areas where it may actually be used. Finally, it maintains knowledge about the previously designed objects; this is somewhat similar to software reuse. Furthermore, IIICAD uses AI techniques in the following areas: formalization of design processes, extensional versus intentional descriptions, modal and other non-standard logics as knowledge representation tools; commonsense reasoning about the physical world (naive physics), coupling symbolic and numerical computation; integration of object-oriented and logic programming paradigms, and development of a common base language for design.

Intelligent CAD Systems III

Designing often involves rather complex processes of reasoning. For building knowledge-based systems for designing, a detailed logical analysis of these processes is inevitable. This paper aims to present a logical framework for describing the steps in a design process as logical inferences. To represent the various kinds of reasoning involved, this framework uses reasoning about viewpoints and reasoning about partial models. These are particular kinds of meta-level reasoning. The logical framework, which is presented in this paper, offers a basis for a formal specification of knowledge-based systems for design.

Design process representation in ADDL

This paper presents the use of ADDL (Artifact and Design Description Language) for design process representation in an intelligent CAD system. ADDL is a special purpose programming language which conceived at the Centre for Mathematics and Computer Science (CWI). It is now being further developed both at the University of Tokyo and at CWI. ADDL is designed for implementing systems which assist a designer in performing a design task. It allows dynamic design object descriptions and a flexible design process representation. In this paper we briefly introduce design object representation in ADDL and elaborate on design process representation. In particular, we pay attention to the multi-world mechanism and the scenario interpreter. In the last section the actual implementation of ADDL on top of Smalltalk-80† is discussed.

Qualitative reasoning about design objects

Abstract This paper presents an intelligent design system which interactively assists a designer during the design process. The system is based on a general design model by which design is viewed as a stepwise refinement process. During this process a model of the design object is gradually refined from a rough abstract model to an exact description meeting the desired specifications. This model is called a meta-model since it is used as a central model from which aspect models are derived. For the meta-model description we use a qualitative model which describes the design object in terms of function and behavior. The system is a so called empty shell since it is only a framework on which an intelligent CAD system can be built. As an example we show an intelligent CAD system for the key design of a technical device in order to visualize the phenomenon of aquaplaning.

Intelligent user interface for intelligent CAD

A user cannot fully exploit the capabilities of an intelligent CAD system unless the user interface is equally powerful. In this paper we list the general and design-related criteria of intelligent communication. The emphasis is on the semantics of the inputs/outputs in context of communication, the design process, and the design constraints. We give a proposal how to extent a traditional user interface with a monitor component in order to meet the requirements of intelligent communication. The proposal is an implementational model for the communicational tasks of intelligent CAD.

Facial Animation by Synthesis of Captured and Artificial Data

Performer-driven animation has been used with success 1, first of all to reproduce human body motion. While there are different capturing hardware-software systems to map the motion of a performer on the motion of a model of the body or face, little has been done both on the technical and on the theoretical level to support the inventive re-use of captured data.