Ewa Grabska

New visual languages supporting design of multi-storey buildings

This paper deals with designing multi-storey buildings with the use of a knowledge-based visual design support system. In this system two visual languages for creating design solutions by the designer are proposed. The first one allows the designer to design 2D floor layouts, while the second one is dedicated to creating 3D building structures. The generated design solutions in the form of drawings are internally represented as hierarchical hypergraphs gathering design knowledge on which reasoning about designs can be based. The approach is illustrated by example of designing a three-storey house.

A Graph Grammar Model of the hp Adaptive Three Dimensional Finite Element Method. Part I

The first part of our paper presents a composite programmable graph grammar model for the self-adaptive two dimensional hp Finite Element Method algorithms (2D hp-FEM) with mixed triangular and rectangular finite elements. The two dimensional model is a starting point for the three dimensional model of self-adaptive hp-FEM presented in the second part of this paper. A computational mesh is represented by a composite graph. The operations performed over the mesh are expressed by the graph grammar rules. The three dimensional model is based on the extension of the two dimensional model with rectangular finite elements. In the second part of this paper, we conclude the presentation with numerical examples concerning the generation of the optimal mesh for simulation of the Step-and-Flash Imprint Lithography (SFIL).

Graph Transformations for Modeling hp-Adaptive Finite Element Method with Triangular Elements

The paper presents composition graph (CP-graph) grammar, which consists of a set of CP-graph transformations, suitable for modeling triangular finite element mesh transformations utilized by the self-adaptive hpFinite Element Method (FEM). The hpadaptive FEM allows to utilize distributed computational meshes, with finite elements of various size (thus hstands for element diameter) and polynomial orders of approximation varying locally, on finite elements edges and interiors (thus pstands for polynomial order of approximation). The computational triangular mesh is represented by attributed CP-graph. The proposed graph transformations model the initial mesh generation, procedure of hrefinement (breaking selected finite elements into son elements), and prefinement (adjusting polynomial orders of approximation on selected element edges and interiors). The graph grammar has been defined and verified by implemented graph grammar transformation software tool.

Graph Transformations for Modeling hp-Adaptive Finite Element Method with Mixed Triangular and Rectangular Elements

The paper presents composition graph (CP-graph) grammar, which consists of a set of CP-graph transformations, suitable for modeling transformations of two dimensional meshes with rectangular elements mixed with triangular elements. The mixed meshes are utilized by the self-adaptive hp Finite Element Method (FEM) extended to support triangular and rectangular elements. The hp -FEM generates a sequence of mixed triangular and rectangular element meshes providing exponential convergence of the numerical error with respect to the mesh size. This is done be executing several h or p refinements over an initial mesh. The mixed finite element mesh is represented by attributed CP-graph. The proposed graph transformations model the initial mesh generation as well as mesh refinements. The proposed extended graph grammar has been defined and verified by using implemented software.

Applying cooperating distributed graph grammars in computer aided design

This paper deals with a graph grammar model of cooperation and distribution for generating designs in computer aided design domain. It is based on earlier research in formal language theory based models for design, especially graph grammars, and also on the developments in the theory of grammar systems. The motivation for the idea presented is given and some possible modes of application are briefly described.

Assisting Creativity by Composite Representation

The paper presents a composite syntactic-semantic representation of objects that is particularly suited for creative design in engineering. This representation is to a great extent oriented towards visual evaluation. The role of emergence both in art and in engineering design is discussed firstly. It is shown on examples taken from Escher’s prints, Civil Engineering and Mechanical Engineering that the emergence can occur with respect to the shape of the object or to its internal structure or topology. The composite representation supports the search for alternative solutions in both domains. It has been implemented as a design tool including the editor of graph grammars, the generator of composition graphs, the library of primitives and the visualisation module.

Converting function into object

The aim of the present paper is to show how the multi-layered graph-based representation could stimulate creative thinking in design. The prototype software developed in this project allows the user to define functional requirements for the designed object and to transform them into the object itself. It is done in several phases and the representation scheme encourages the designer to look for alternatives, analogies and novel solutions at each level of abstraction. The proposed methodology is illustrated by simple example of designing the teapot but the same principles apply for each artefact.

Designing floor-layouts with the assistance of curious agents

The paper deals with visual computational design in which emergence is a key to creativity. The presented framework for conceptual design uses shape grammars and curious agent assistants. The intelligent agents perceive the changing environment and emergent phenomena that occur in it. Interacting with each other and the designer they look for the most original and plausible solutions to a given design task. The approach is illustrated by the example of a designing floor-layouts.

HYPERGRAPHS IN DIAGRAMMATIC DESIGN

A specific diagram language, called the floor-layout language, is considered. It allows to edit floor-layouts maintaining specified restrictions. An internal diagram representation in the form of hypergraphs needed for syntactic analysis is described. Some examples of designing floor-layouts are presented.

Graph Visualization in ArchiCAD

This paper deals with computer aided design in architecture. A two-phase representation of objects is used that separates the definition of structure from the interpretation. It is shown how to integrate such a graph-based representation with the commercial ArchiCAD system used by many architects. Preliminary results reported in this paper indicate that it is possible to augment ArchiCAD by a graph grammar-based tool that would allow the designer to generate alternative solutions and to evaluate them.