CumInCAD is a Cumulative Index about publications in Computer Aided Architectural Design
supported by the sibling associations ACADIA, CAADRIA, eCAADe, SIGraDi, ASCAAD and CAAD futures

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Hits 1 to 20 of 2550

_id 75a8
authors Achten, Henri H.
year 1997
title Generic representations : an approach for modelling procedural and declarative knowledge of building types in architectural design
source Eindhoven University of Technology
summary The building type is a knowledge structure that is recognised as an important element in the architectural design process. For an architect, the type provides information about norms, layout, appearance, etc. of the kind of building that is being designed. Questions that seem unresolved about (computational) approaches to building types are the relationship between the many kinds of instances that are generally recognised as belonging to a particular building type, the way a type can deal with varying briefs (or with mixed use), and how a type can accommodate different sites. Approaches that aim to model building types as data structures of interrelated variables (so-called ‘prototypes’) face problems clarifying these questions. The research work at hand proposes to investigate the role of knowledge associated with building types in the design process. Knowledge of the building type must be represented during the design process. Therefore, it is necessary to find a representation which supports design decisions, supports the changes and transformations of the design during the design process, encompasses knowledge of the design task, and which relates to the way architects design. It is proposed in the research work that graphic representations can be used as a medium to encode knowledge of the building type. This is possible if they consistently encode the things they represent; if their knowledge content can be derived, and if they are versatile enough to support a design process of a building belonging to a type. A graphic representation consists of graphic entities such as vertices, lines, planes, shapes, symbols, etc. Establishing a graphic representation implies making design decisions with respect to these entities. Therefore it is necessary to identify the elements of the graphic representation that play a role in decision making. An approach based on the concept of ‘graphic units’ is developed. A graphic unit is a particular set of graphic entities that has some constant meaning. Examples are: zone, circulation scheme, axial system, and contour. Each graphic unit implies a particular kind of design decision (e.g. functional areas, system of circulation, spatial organisation, and layout of the building). By differentiating between appearance and meaning, it is possible to define the graphic unit relatively shape-independent. If a number of graphic representations have the same graphic units, they deal with the same kind of design decisions. Graphic representations that have such a specifically defined knowledge content are called ‘generic representations.’ An analysis of over 220 graphic representations in the literature on architecture results in 24 graphic units and 50 generic representations. For each generic representation the design decisions are identified. These decisions are informed by the nature of the design task at hand. If the design task is a building belonging to a building type, then knowledge of the building type is required. In a single generic representation knowledge of norms, rules, and principles associated with the building type are used. Therefore, a single generic representation encodes declarative knowledge of the building type. A sequence of generic representations encodes a series of design decisions which are informed by the design task. If the design task is a building type, then procedural knowledge of the building type is used. By means of the graphic unit and generic representation, it is possible to identify a number of relations that determine sequences of generic representations. These relations are: additional graphic units, themes of generic representations, and successive graphic units. Additional graphic units defines subsequent generic representations by adding a new graphic unit. Themes of generic representations defines groups of generic representations that deal with the same kind of design decisions. Successive graphic units defines preconditions for subsequent or previous generic representations. On the basis of themes it is possible to define six general sequences of generic representations. On the basis of additional and successive graphic units it is possible to define sequences of generic representations in themes. On the basis of these sequences, one particular sequence of 23 generic representations is defined. The particular sequence of generic representations structures the decision process of a building type. In order to test this assertion, the particular sequence is applied to the office building type. For each generic representation, it is possible to establish a graphic representation that follows the definition of the graphic units and to apply the required statements from the office building knowledge base. The application results in a sequence of graphic representations that particularises an office building design. Implementation of seven generic representations in a computer aided design system demonstrates the use of generic representations for design support. The set is large enough to provide additional weight to the conclusion that generic representations map declarative and procedural knowledge of the building type.
series thesis:PhD
email
more http://alexandria.tue.nl/extra2/9703788.pdf
last changed 2003/11/21 15:15

_id 58f4
authors Barequet, G. and Kumar, S.
year 1997
title Repairing CAD models
source Proceedings of IEEE Visualizationí97, pp. 363-370
summary We describe an algorithm for repairing polyhedral CAD models that have errors in their B-REP. Errors like cracks, degeneracies, duplication, holes and overlaps are usually introduced in solid models due to imprecise arithmetic, model transformations, designer's fault, programming bugs, etc. Such errors often hamper further processing like finite element analysis, radiosity computation and rapid prototyping. Our fault-repair algorithm converts an unordered collection of polygons to a shared-vertex representation to help eliminate errors. This is done by choosing, for each polygon edge, the most appropriate edge to unify it with. The two edges are then geometrically merged into one, by moving vertices. At the end of this process, each polygon edge is either coincident with another or is a boundary edge for a polygonal hole or a dangling wall and may be appropriately repaired. Finally, in order to allow user- inspection of the automatic corrections, we produce a visualization of the repair and let the user mark the corrections that conflict with the original design intent. A second iteration of the correction algorithm then produces a repair that is commensurate with the intent. Thus, by involving the users in a feedback loop, we are able to refine the correction to their satisfaction.
series other
email
last changed 2003/04/23 15:14

_id 823f
authors Bignon, J.C., Halin, G. and Humbert, P.
year 1997
title Hypermedia Structuring of the Technical Documentation for the Architectural Aided Design
source CAAD Futures 1997 [Conference Proceedings / ISBN 0-7923-4726-9] München (Germany), 4-6 August 1997, pp. 843-848
summary The definition of an universal structuring model of the technical documentation is arduous, indeed utopian considering the great number of products and the diversity of relative information. To answer this situation we are trying to develop a general approach of the documentation. The document is the base entity of documentation structuring and it represents a coherent informative unit. We propose a model of document hypermedia structuring. This model allows the definition, the presentation, the navigation and the retrieval of general information on building products by a document manipulation. It is associated with a hypermedia design method adapted to document management. This method proposes, after the identification of the user, three phases of hypermedia definition : data definition, navigation definition and user interface definition. The model of a hypermedia structuring of the technical documentation proposed in this article is at once independent of available information on products, open, and makes easier the addition of new navigational functions.
series CAAD Futures
email
last changed 2003/11/21 15:16

_id ccc0
authors Braithwaite, G., Radford, A., Huang, E. , Chang, T.W., Jones, D., Woodbury, R. and Sweeting, R.
year 1997
title The Computer Modeling of Development Proposals: A Routine Part of Development Control
source CAADRIA ‘97 [Proceedings of the Second Conference on Computer Aided Architectural Design Research in Asia / ISBN 957-575-057-8] Taiwan 17-19 April 1997, pp. 123-132
doi https://doi.org/10.52842/conf.caadria.1997.123
summary This paper describes and discusses the aims and practicalities involved in the computer modeling of contentious development applications becoming accepted as a routine part of the processes of development control. It uses three case studies drawn from the University of Adelaide’s work with the City of Adelaide in Australia to delineate the role of 3D computer models of proposed new buildings and their immediate surroundings in the public understanding of the streetscape, neighbourhood context, overshadowing and overlooking implications of the proposals.
keywords 3D City Modeling
series CAADRIA
last changed 2022/06/07 07:54

_id 63ea
authors Brown, A.G.P., Berridge, P. and Mackie, D.
year 1997
title Gaming as a Vehicle for Collaborative Designcollaborative design
source Challenges of the Future [15th eCAADe Conference Proceedings / ISBN 0-9523687-3-0] Vienna (Austria) 17-20 September 1997
doi https://doi.org/10.52842/conf.ecaade.1997.x.c5x
summary This paper outlines one approach to addressing the problem of participation in a properly understood process and goes on to show how the principles used are being reinforced by an interactive computer based application.
keywords Collaborative Design
series eCAADe
email
more http://info.tuwien.ac.at/ecaade/proc/berridge/berridge.htm
last changed 2022/06/07 07:50

_id ffe2
authors Carrar, G., Luna, F. and Rajchman, A.
year 1999
title Cúpulas Telefónicas - Mobiliario Urbano, Diseño Industrial aplicado a una empresa de servicios (Telephone Cupolas - Urban Furniture, Industrial Design Applied to a Company of Services)
source III Congreso Iberoamericano de Grafico Digital [SIGRADI Conference Proceedings] Montevideo (Uruguay) September 29th - October 1st 1999, pp. 426-409
summary By november 1996, the state telecomunication company called for a national booth design contest. The idea was to use the awarded design shortly as part of the renovation of the public phone service. Gruppo MDM won the design contest and was contracted to do the manufacture technical drawings and a prototype which was tested during 1997. By 1997, an international bid was held, including the awarded project. Gruppo MDM was contracted for the follow up of the manufacture process, including research of suppliers worldwide, materials arriving on time with the quality required, verifying local suppliers with deadlines and quality controlls according to the specifications.
series SIGRADI
email
last changed 2016/03/10 09:48

_id aa2f
authors Carrara, G., Fioravanti, A. and Novembri, G.
year 1997
title An Intelligent Assistant for the Architectural Design Studio
source Challenges of the Future [15th eCAADe Conference Proceedings / ISBN 0-9523687-3-0] Vienna (Austria) 17-20 September 1997
doi https://doi.org/10.52842/conf.ecaade.1997.x.a3a
summary It seems by now fairly accepted by many researchers in the field of the Computer Aided Design that the way to realise support tools for the architectural design is by means of the realisation of Intelligent Assistants. This kind of computer program, based on the Knowledge Engineering and machine learning, finds his power and effectiveness by the Knowledge Base on which it is based. Moreover, it appears evident that the modalities of dialogue among architects and operators in the field of building industry, are inadequate to support the exchange of information that the use of these tools requires.

In fact, many efforts at international level are in progress to define tools in order to make easier the multiple exchange of information in different fields of building design. Concerning this point, protocol and ontology of structured information interchanges constitute the first steps in this sense, e.g. those under standardisation by ISO (STEP), PDT models and Esprit project ToCEE. To model these problems it has brought forth a new research field: the collaborative design one, an evolution of distributed work and concurrent design.

The CAAD Laboratory of Dipartimento di Architettura and Urbanistica per l'Ingegneria has carried out a software prototype, KAAD, based on Knowledge Engineering in the fields of hospital building and of building for aged people. This software is composed by an Interface, a Knowledge Base, a Database and Constraints. The Knowledge Base has been codified by using the formal structure of frames, and has been implemented by the Lisp language. All the elements of KB are objects

keywords Design Studio
series eCAADe
email
more http://info.tuwien.ac.at/ecaade/proc/carrara/carrara.htm
last changed 2022/06/07 07:50

_id 88f9
authors Carrara, G., Novembri, G., Zorgno, A.M., Brusasco, P.L.
year 1997
title Virtual Studio of Design and Technology on Internet (I) - Educator's approach
source Challenges of the Future [15th eCAADe Conference Proceedings / ISBN 0-9523687-3-0] Vienna (Austria) 17-20 September 1997
doi https://doi.org/10.52842/conf.ecaade.1997.x.n2w
summary This paper presents a teaching experience involving students and professors from various universities, in Italy and abroad, which began in 1996 and is still on going. The Virtual Studios on the Internet (VSI) have some features in common with the Teaching Studios planned for the new programme of the faculties of Architecture in Italian universities. These are the definition of a common design theme, and the participation of disciplinary teachers. The greatest difference is in the modes of collaboration, which is achieved through information and communication technologies. The chief result of this is that the various work groups in different places can work and collaborate at the same time: the computer networks provide the means to express, communicate and share the design project.
keywords CAAD, Teaching of architectural design, Shared virtual reality, Virtualdesign studio, Collective intelligence.
series eCAADe
email
more http://info.tuwien.ac.at/ecaade/proc/lvi_i&ii/zorgno.html
last changed 2022/06/07 07:50

_id b4c4
authors Carrara, G., Fioravanti, A. and Novembri, G.
year 2000
title A framework for an Architectural Collaborative Design
source Promise and Reality: State of the Art versus State of Practice in Computing for the Design and Planning Process [18th eCAADe Conference Proceedings / ISBN 0-9523687-6-5] Weimar (Germany) 22-24 June 2000, pp. 57-60
doi https://doi.org/10.52842/conf.ecaade.2000.057
summary The building industry involves a larger number of disciplines, operators and professionals than other industrial processes. Its peculiarity is that the products (building objects) have a number of parts (building elements) that does not differ much from the number of classes into which building objects can be conceptually subdivided. Another important characteristic is that the building industry produces unique products (de Vries and van Zutphen, 1992). This is not an isolated situation but indeed one that is spreading also in other industrial fields. For example, production niches have proved successful in the automotive and computer industries (Carrara, Fioravanti, & Novembri, 1989). Building design is a complex multi-disciplinary process, which demands a high degree of co-ordination and co-operation among separate teams, each having its own specific knowledge and its own set of specific design tools. Establishing an environment for design tool integration is a prerequisite for network-based distributed work. It was attempted to solve the problem of efficient, user-friendly, and fast information exchange among operators by treating it simply as an exchange of data. But the failure of IGES, CGM, PHIGS confirms that data have different meanings and importance in different contexts. The STandard for Exchange of Product data, ISO 10303 Part 106 BCCM, relating to AEC field (Wix, 1997), seems to be too complex to be applied to professional studios. Moreover its structure is too deep and the conceptual classifications based on it do not allow multi-inheritance (Ekholm, 1996). From now on we shall adopt the BCCM semantic that defines the actor as "a functional participant in building construction"; and we shall define designer as "every member of the class formed by designers" (architects, engineers, town-planners, construction managers, etc.).
keywords Architectural Design Process, Collaborative Design, Knowledge Engineering, Dynamic Object Oriented Programming
series eCAADe
email
more http://www.uni-weimar.de/ecaade/
last changed 2022/06/07 07:55

_id 80f7
authors Carrara, G., Fioravanti, A. and Novembri, G.
year 2001
title Knowledge-based System to Support Architectural Design - Intelligent objects, project net-constraints, collaborative work
source Architectural Information Management [19th eCAADe Conference Proceedings / ISBN 0-9523687-8-1] Helsinki (Finland) 29-31 August 2001, pp. 80-85
doi https://doi.org/10.52842/conf.ecaade.2001.080
summary The architectural design business is marked by a progressive increase in operators all cooperating towards the realization of building structures and complex infrastructures (Jenckes, 1997). This type of design implies the simultaneous activity of specialists in different fields, often working a considerable distance apart, on increasingly distributed design studies. Collaborative Architectural Design comprises a vast field of studies that embraces also these sectors and problems. To mention but a few: communication among operators in the building and design sector; design process system logic architecture; conceptual structure of the building organism; building component representation; conflict identification and management; sharing of knowledge; and also, user interface; global evaluation of solutions adopted; IT definition of objects; inter-object communication (in the IT sense). The point of view of the research is that of the designers of the architectural artefact (Simon, 1996); its focus consists of the relations among the various design operators and among the latter and the information exchanged: the Building Objects. Its primary research goal is thus the conceptual structure of the building organism for the purpose of managing conflicts and developing possible methods of resolving them.
keywords Keywords. Collaborative Design, Architectural And Building Knowledge, Distributed Knowledge Bases, Information Management, Multidisciplinarity
series eCAADe
email
last changed 2022/06/07 07:55

_id 7a20
id 7a20
authors Carrara, G., Fioravanti, A.
year 2002
title SHARED SPACE’ AND ‘PUBLIC SPACE’ DIALECTICS IN COLLABORATIVE ARCHITECTURAL DESIGN.
source Proceedings of Collaborative Decision-Support Systems Focus Symposium, 30th July, 2002; under the auspices of InterSymp-2002, 14° International Conference on Systems Research, Informatics and Cybernetics, 2002, Baden-Baden, pg. 27-44.
summary The present paper describes on-going research on Collaborative Design. The proposed model, the resulting system and its implementation refer mainly to architectural and building design in the modes and forms in which it is carried on in advanced design firms. The model may actually be used effectively also in other environments. The research simultaneously pursues an integrated model of the: a) structure of the networked architectural design process (operators, activities, phases and resources); b) required knowledge (distributed and functional to the operators and the process phases). The article focuses on the first aspect of the model: the relationship that exists among the various ‘actors’ in the design process (according to the STEP-ISO definition, Wix, 1997) during the various stages of its development (McKinney and Fischer, 1998). In Collaborative Design support systems this aspect touches on a number of different problems: database structure, homogeneity of the knowledge bases, the creation of knowledge bases (Galle, 1995), the representation of the IT datum (Carrara et al., 1994; Pohl and Myers, 1994; Papamichael et al., 1996; Rosenmann and Gero, 1996; Eastman et al., 1997; Eastman, 1998; Kim, et al., 1997; Kavakli, 2001). Decision-making support and the relationship between ‘private’ design space (involving the decisions of the individual design team) and the ‘shared’ design space (involving the decisions of all the design teams, Zang and Norman, 1994) are the specific topic of the present article.

Decisions taken in the ‘private design space’ of the design team or ‘actor’ are closely related to the type of support that can be provided by a Collaborative Design system: automatic checks performed by activating procedures and methods, reporting of 'local' conflicts, methods and knowledge for the resolution of ‘local’ conflicts, creation of new IT objects/ building components, who the objects must refer to (the ‘owner’), 'situated' aspects (Gero and Reffat, 2001) of the IT objects/building components.

Decisions taken in the ‘shared design space’ involve aspects that are typical of networked design and that are partially present in the ‘private’ design space. Cross-checking, reporting of ‘global’ conflicts to all those concerned, even those who are unaware they are concerned, methods for their resolution, the modification of data structure and interface according to the actors interacting with it and the design phase, the definition of a 'dominus' for every IT object (i.e. the decision-maker, according to the design phase and the creation of the object). All this is made possible both by the model for representing the building (Carrara and Fioravanti, 2001), and by the type of IT representation of the individual building components, using the methods and techniques of Knowledge Engineering through a structured set of Knowledge Bases, Inference Engines and Databases. The aim is to develop suitable tools for supporting integrated Process/Product design activity by means of a effective and innovative representation of building entities (technical components, constraints, methods) in order to manage and resolve conflicts generated during the design activity.

keywords Collaborative Design, Architectural Design, Distributed Knowledge Bases, ‘Situated’ Object, Process/Product Model, Private/Shared ‘Design Space’, Conflict Reduction.
series other
type symposium
email
last changed 2005/03/30 16:25

_id 6279
id 6279
authors Carrara, G.; Fioravanti, A.
year 2002
title Private Space' and ‘Shared Space’ Dialectics in Collaborative Architectural Design
source InterSymp 2002 - 14th International Conference on Systems Research, Informatics and Cybernetics (July 29 - August 3, 2002), pp 28-44.
summary The present paper describes on-going research on Collaborative Design. The proposed model, the resulting system and its implementation refer mainly to architectural and building design in the modes and forms in which it is carried on in advanced design firms. The model may actually be used effectively also in other environments. The research simultaneously pursues an integrated model of the: a) structure of the networked architectural design process (operators, activities, phases and resources); b) required knowledge (distributed and functional to the operators and the process phases). The article focuses on the first aspect of the model: the relationship that exists among the various ‘actors’ in the design process (according to the STEP-ISO definition, Wix, 1997) during the various stages of its development (McKinney and Fischer, 1998). In Collaborative Design support systems this aspect touches on a number of different problems: database structure, homogeneity of the knowledge bases, the creation of knowledge bases (Galle, 1995), the representation of the IT datum (Carrara et al., 1994; Pohl and Myers, 1994; Papamichael et al., 1996; Rosenmann and Gero, 1996; Eastman et al., 1997; Eastman, 1998; Kim, et al., 1997; Kavakli, 2001). Decision-making support and the relationship between ‘private’ design space (involving the decisions of the individual design team) and the ‘shared’ design space (involving the decisions of all the design teams, Zang and Norman, 1994) are the specific topic of the present article.

Decisions taken in the ‘private design space’ of the design team or ‘actor’ are closely related to the type of support that can be provided by a Collaborative Design system: automatic checks performed by activating procedures and methods, reporting of 'local' conflicts, methods and knowledge for the resolution of ‘local’ conflicts, creation of new IT objects/ building components, who the objects must refer to (the ‘owner’), 'situated' aspects (Gero and Reffat, 2001) of the IT objects/building components.

Decisions taken in the ‘shared design space’ involve aspects that are typical of networked design and that are partially present in the ‘private’ design space. Cross-checking, reporting of ‘global’ conflicts to all those concerned, even those who are unaware they are concerned, methods for their resolution, the modification of data structure and interface according to the actors interacting with it and the design phase, the definition of a 'dominus' for every IT object (i.e. the decision-maker, according to the design phase and the creation of the object). All this is made possible both by the model for representing the building (Carrara and Fioravanti, 2001), and by the type of IT representation of the individual building components, using the methods and techniques of Knowledge Engineering through a structured set of Knowledge Bases, Inference Engines and Databases. The aim is to develop suitable tools for supporting integrated Process/Product design activity by means of a effective and innovative representation of building entities (technical components, constraints, methods) in order to manage and resolve conflicts generated during the design activity.

keywords Collaborative Design, Architectural Design, Distributed Knowledge Bases, ‘Situated’ Object, Process/Product Model, Private/Shared ‘Design Space’, Conflict Reduction.
series other
type symposium
email
last changed 2012/12/04 07:53

_id 508b
authors Chiu, Mao-Lin
year 1997
title Representations and Communication channels in collaborative architectural design
source Mary L. M., John S. G., Fay S., editor, Formal Aspects of Collaborative CAD, IFIP97, Australia, Februrary, 1997, pp. 77-96
summary Collaborative design requires participation of individuals and coordination of design information and tasks. This paper focuses on the representations and communication channels in collaboration design. On the basis of a design communication model and findings of four collaborative design case studies, the phenomena of design communication are presented. The study also examines when the conditions of collaboration are achieved and what kinds of interfaces in computer-mediated collaborative work are needed, and propose a theme-oriented interface for computer-mediated collaborative design.
series other
email
last changed 2003/04/23 15:14

_id 7ebf
authors Clark, G. and Mehta, P.
year 1997
title Artificial intelligence and networking in integrated building management systems
source Automation in Construction 6 (5-6) (1997) pp. 481-498
summary In recent years the emphasis has moved towards integrating all a building's systems via centralised building management systems (BMS). To provide a more intelligent approach to the facility management, safety and energy control in building management systems (IBMS), this paper proposes a methodology for integrating the data within a BMS via a single multi-media networking technology and providing the BMS with artificial intelligence (AI) through the use of knowledge-based systems (KBS) technology. By means of artificial intelligence, the system is capable of assessing, diagnosing and suggesting the best solution. This paper outlines how AI techniques can enhance the control of HVAC systems for occupant comfort and efficient running costs based on occupancy prediction. Also load control and load balancing are investigated. Instead of just using pre-programmed load priorities, this work has investigated the use of a dynamic system of priorities which are based on many factors such as area usage, occupancy, time of day and real time environmental conditions. This control strategy which is based on a set of rules running on the central control system, makes use of information gathered from outstations throughout the building and communicated via the building's data-bus.
series journal paper
more http://www.elsevier.com/locate/autcon
last changed 2003/05/15 21:22

_id ga9921
id ga9921
authors Coates, P.S. and Hazarika, L.
year 1999
title The use of genetic programming for applications in the field of spatial composition
source International Conference on Generative Art
summary Architectural design teaching using computers has been a preoccupation of CECA since 1991. All design tutors provide their students with a set of models and ways to form, and we have explored a set of approaches including cellular automata, genetic programming ,agent based modelling and shape grammars as additional tools with which to explore architectural ( and architectonic) ideas.This paper discusses the use of genetic programming (G.P.) for applications in the field of spatial composition. CECA has been developing the use of Genetic Programming for some time ( see references ) and has covered the evolution of L-Systems production rules( coates 1997, 1999b), and the evolution of generative grammars of form (Coates 1998 1999a). The G.P. was used to generate three-dimensional spatial forms from a set of geometrical structures .The approach uses genetic programming with a Genetic Library (G.Lib) .G.P. provides a way to genetically breed a computer program to solve a problem.G. Lib. enables genetic programming to define potentially useful subroutines dynamically during a run .* Exploring a shape grammar consisting of simple solid primitives and transformations. * Applying a simple fitness function to the solid breeding G.P.* Exploring a shape grammar of composite surface objects. * Developing grammarsfor existing buildings, and creating hybrids. * Exploring the shape grammar of abuilding within a G.P.We will report on new work using a range of different morphologies ( boolean operations, surface operations and grammars of style ) and describe the use of objective functions ( natural selection) and the "eyeball test" ( artificial selection) as ways of controlling and exploring the design spaces thus defined.
series other
more http://www.generativeart.com/
last changed 2003/08/07 17:25

_id 77bc
authors Cohen, S., Elber, G. and Bar-Yehuda, R.
year 1997
title Matching of freeform curves
source Computer-Aided Design, Vol. 29 (5) (1997) pp. 369-378
summary Freeform parametric curves are extensively employed in various fields such as computer graphics, computer vision, robotics, and geometric modeling. While manyapplications exploit and combine univariate freeform entities into more complex forms such as sculptured surfaces, the problem of a fair or even optimal relativeparameterization of freeforms, under some norm, has been rarely considered. In this work, we present a scheme that closely approximates the optimal relativematching between two or even n given freeform curves, under a user's prescribed norm that is based on differential properties of the curves. This matching iscomputed as a reparameterization of n - 1 of the curves that can be applied explicitly using composition. The proposed matching algorithm is completely automaticand has been successfully employed in different applications with several demonstrated herein: metamorphosis of freeform curves with feature preservations, keyframe interpolation for animation, self-intersection free ruled surface construction, and automatic matching of rail curves of blending surfaces.
keywords Dynamic Programming, Tangent/Gauss Map, Feature Recognition, Fairness
series journal paper
last changed 2003/05/15 21:33

_id fd8b
authors Czernuszenko, M., Pape, D., Sandin, D., DeFanti, T., Dawe, G. and Brown, M.
year 1997
title The ImmersaDesk and Infinity Wall projection-based virtual reality displays
source Computer Graphics, 31(2): 46-49, May
summary Virtual reality (VR) can be defined as interactive computer graphics that provides viewer-centered perspective, large field of view and stereo. Head-mounted displays (HMDs) and BOOMs™ achieve these features with small display screens which move with the viewer, close to the viewer's eyes. Projection-based displays, supply these characteristics by placing large, fixed screens more distant from the viewer. The Electronic Visualization Laboratory (EVL) of the University of Illinois at Chicago has specialized in projection-based VR systems. EVL's projection-based VR display, the CAVE™ premiered at the SIGGRAPH 92 conference.In this article we present two new, CAVE-derived, projection-based VR displays developed at EVL: the ImmersaDesk™ and the Infinity Wall™, a VR version of the PowerWall. We describe the different requirements which led to their design, and compare these systems to other VR devices.
series journal paper
last changed 2003/04/23 15:50

_id ddss9829
id ddss9829
authors De Hoog, J., Hendriks, N.A. and Rutten, P.G.S.
year 1998
title Evaluating Office Buildings with MOLCA(Model for Office Life Cycle Assessment)
source Timmermans, Harry (Ed.), Fourth Design and Decision Support Systems in Architecture and Urban Planning Maastricht, the Netherlands), ISBN 90-6814-081-7, July 26-29, 1998
summary MOLCA (Model for Office Life Cycle Assessment) is a project that aims to develop a tool that enables designers and builders to evaluate the environmental impact of their designs (of office buildings) from a environmental point of view. The model used is based on guidelinesgiven by ISO 14000, using the so-called Life Cycle Assessment (LCA) method. The MOLCA project started in 1997 and will be finished in 2001 resulting in the aforementioned tool. MOLCA is a module within broader research conducted at the Eindhoven University of Technology aiming to reduce design risks to a minimum in the early design stages.Since the MOLCA project started two major case-studies have been carried out. One into the difference in environmental load caused by using concrete and steel roof systems respectively and the role of recycling. The second study focused on biases in LCA data and how to handle them. For the simulations a computer-model named SimaPro was used, using the world-wide accepted method developed by CML (Centre for the Environment, Leiden, the Netherlands). With this model different life-cycle scenarios were studied and evaluated. Based on those two case studies and a third one into an office area, a first model has been developed.Bottle-neck in this field of study is estimating average recycling and re-use percentages of the total flow of material waste in the building sector and collecting reliable process data. Another problem within LCA studies is estimating the reliability of the input data and modelling uncertainties. All these topics will be subject of further analysis.
keywords Life-Cycle Assessment, Office Buildings, Uncertainties in LCA
series DDSS
last changed 2003/08/07 16:36

_id b3b1
authors Ebrahim, Mostafa Abdel-Bary
year 1997
title Application and evaluation of digital image techniques in close range photogrammetry
source University of Innsbruck
summary Most of the orthomapping techniques that are used in the present are restricted to surfaces that arise from a function of 'ground co- ordinates' z = f (x, y) , so-called 2.5D objects. Some techniques are also restricted to surfaces with kind of smooth shape or even to regular surfaces, but all of them are established to rectify images (although increasingly digitally). A new approach has been established for digital restitution and orthomapping of close range objects of almost any shape and size and with almost no restriction to images or objects. The idea of this approach is an inversion of the photographic technique and is (on the contrary to the 'rectification approach') strictly object oriented. All of the objects are regarded to be describable in their geometrical shape by a number of particular faces that can be regular or irregular but can anyway be created in a CAD environment. The data needed to get this surface can come from any photogrammetric, tachometric or other source with any particular one wants to have for the results. All the details that lie on that surface don't have to be restituted by analog or analytical point measurement but can after that be projected onto this surface from any photo, from any side and with any camera they have been taken. A 'Digital Projector' does the projection of the photos from the same positions and with the same inner orientation as of photographic camera. Using this approach any measurements of any details on the facades can be done easily. No details of the object can be neglected, none can be forgotten, no prior filtering of details has preceded this using. The full information of the original photos is available in the results. The results of the restitution can be presented in many ways. One of them is create orthoimages in any scale. Other results are any perspective or parallel view of the object. Other use of the strict 3D map-covered object for visualization (e.g. in architecture and archaeology application) is possible  
keywords Digital Image; Digital Projector; Close Range Photogrammetry; Architectural Photogrammetry; 2.5d Objects; Visualization
series thesis:PhD
email
more http://www.arcs.ac.at/dissdb/rn027356
last changed 2003/02/12 22:37

_id d4b1
authors Egglib, L., Ching-yaob, H., Brüderlinb, B. and Elbera, G.
year 1997
title Inferring 3D models from freehand sketches and constraints
source Computer-Aided Design, Vol. 29 (2) (1997) pp. 101-112
summary This paper describes `Quick-sketch', a 2D and 3D modelling tool for pen-based computers. Users of this system define a model by simple pen strokes, drawn directlyon the screen of a pen-based PC. Exact shapes and geometric relationships are interpreted from the sketch. The system can also be used to sketch 3D solid objects andB-spline surfaces. These objects may be refined by defining 2D and 3D geometric constraints. A novel graph-based constraint solver is used to establish the geometricrelationships, or to maintain them when manipulating the objects interactively. The approach presented here is a first step towards a conceptual design system.Quick-sketch can be used as a hand sketching front-end to more sophisticated modelling, rendering or animation systems.
keywords Geometric Constraints, Conceptual Design, Free-Hand Sketch Interpretation
series journal paper
last changed 2003/05/15 21:33

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