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 218

_id f586
authors Gabriel, G. and Maher, M.L.
year 2000
title Analysis of design communication with and without computer mediation
source Proceedings of Co-designing 2000, pp. 329-337
summary With recent developments in CAD and communication technologies, the way we visualise and communicate design representations is changing. A matter of great interest to architects, practitioners and researchers alike, is how computer technology might affect the way they think and work. The concern is not about the notion of 'support' alone, but about ensuring that computers do not disrupt the design process and collaborative activity already going on (Bannon and Schmidt, 1991). Designing new collaborative tools will then have to be guided by a better understanding of how collaborative work is accomplished and by understanding what resources the collaborators use and what hindrances they encounter in their work (Finholt et al., 1990). Designing, as a more abstract notion, is different than having a business meeting using video conferencing. In design it is more important to 'see' what is being discussed rather than 'watch' the other person(s) involved in the discussion. In other words the data being conveyed might be of more importance than the method with which it is communicated (See Kvan, 1994). Similarly, we believe that by using text instead of audio as a medium for verbal communication, verbal representations can then be recorded alongside graphical representations for later retrieval and use. In this paper we present the results of a study on collaborative design in three different environments: face-to-face (FTF), computer-mediated using video conferencing (CMCD-a), and computer-mediated using "talk by typing" (CMCD-b). The underlying aim is to establish a clearer notion of the collaborative needs of architects using computer-mediation. In turn this has the potential in assisting developers when designing new collaborative tools and in assisting designers when selecting an environment for a collaborative session.
series other
last changed 2003/04/23 15:50

_id ddss2006-hb-487
id DDSS2006-HB-487
authors Chien-Tung Chen and Teng-Wen Chang
year 2006
title 1:1 Spatially Augmented Reality Design Environment
source Van Leeuwen, J.P. and H.J.P. Timmermans (eds.) 2006, Innovations in Design & Decision Support Systems in Architecture and Urban Planning, Dordrecht: Springer, ISBN-10: 1-4020-5059-3, ISBN-13: 978-1-4020-5059-6, p. 487-499
summary With the development of ubiquitous computing (Weiser, 1991), what will become of the traditional media such as pen and sketches, especially in the design education environment? Or what will they be transformed into? In this research, we focus on the interior design process with a particular type of media-1:1 spatially augmented reality design environment (SARDE). In this research, we tried to implement SARDE and have a scenario experiment to check how designers interact with such design media. Furthermore, through this research, we have come to know more about how designers use design media to represent their design dream.
keywords Design & Decision Support Systems, Spatially Augmented Reality, Architecture Education, and Computer Visualization
series DDSS
last changed 2006/08/29 12:55

_id 1839
authors Papamichael, Konstantinos Michael
year 1991
title Design process and knowledge possibilities and limitations of computer-aided design
source University of California, Berkeley
summary An attempt to determine how computers can be used to assist designers resulted in the development of a design theory, according to which design is 'feeling and thinking while acting.' Design is theorized as living through one's imagination, however being continuously affected by real life itself. The design process is decomposed into elementary activities that are characterized with respect to the nature of knowledge requirements and the degree to which they can be specified and delegated to computers. The results are considered as criteria to determine possibilities and limitations of computer-aided design. An integration of a variety of computer applications tools is proposed towards the design and development of a computer-based Design Support Environment (DSE), that is applicable to any design domain. The proposed DSE automates all specifiable and delegable design activities, while assisting with the nondelegable ones through appropriate user interface. A DSE demonstration prototype is also presented in the Appendix. This prototype addresses the design of fenestration and electric lighting systems of office spaces with respect to comfort, energy and cost.
series thesis:PhD
email
last changed 2003/02/24 20:32

_id c93d
authors Zreik, Khaldoun
year 1991
title What Could Artificial Intelligence Know about the Knowledge Involved in the Design Process?
source Computer Aided Architectural Design Futures: Education, Research, Applications [CAAD Futures ‘91 Conference Proceedings / ISBN 3-528-08821-4] Zürich (Switzerland), July 1991, pp. 395-410
summary The nature of the knowledge involved in the design process is very specific and it is incompletely known. Its control becomes very complicated owing to the large number of dynamic parameters and functions which define the relationships between one another. So we consider two relevant facts: 1.) all knowledge involved in the design process could not have been foreseen; 2.) the help of computer technology in this domain is badly oriented. Two major questions will be posed here: a. what kind of design knowledge do designers explicitly master? b. and which parts of it can computer technology represent today? // This paper aims to build a simple panorama of the knowledge involved in the architectural design process. Actors, resources and corresponding classifications of this knowledge and also its dynamic distribution will be presented. This paper also throws light upon how important are artificial intelligence sciences and tools for the improvement of the design process computability.
series CAAD Futures
last changed 1999/04/07 12:03

_id 0ab2
authors Amor, R., Hosking, J., Groves, L. and Donn, M.
year 1993
title Design Tool Integration: Model Flexibility for the Building Profession
source Proceedings of Building Systems Automation - Integration, University of Wisconsin-Madison
summary The development of ICAtect, as discussed in the Building Systems Automation and Integration Symposium of 1991, provides a way of integrating simulation tools through a common building model. However, ICAtect is only a small step towards the ultimate goal of total integration and automation of the building design process. In this paper we investigate the next steps on the path toward integration. We examine how models structured to capture the physical attributes of the building, as required by simulation tools, can be used to converse with knowledge-based systems. We consider the types of mappings that occur in the often different views of a building held by these two classes of design tools. This leads us to examine the need for multiple views of a common building model. We then extend our analysis from the views required by simulation and knowledge-based systems, to those required by different segments of the building profession (e.g. architects, engineers, developers, etc.) to converse with such an integrated system. This indicates a need to provide a flexible method of accessing data in the common building model to facilitate use by different building professionals with varying specialities and levels of expertise.
series journal paper
email
last changed 2003/05/15 21:22

_id 8db6
authors Bijl, Aart
year 1991
title On Knowing - Feeling and Expression
source Computer Aided Architectural Design Futures: Education, Research, Applications [CAAD Futures ‘91 Conference Proceedings / ISBN 3-528-08821-4] Zürich (Switzerland), July 1991, pp. 157-176
summary The basic assumptions for CAD, and for any use of computers, are re-examined. They refer to how we know things, how we think of knowledge being represented, and the impact of representation techniques on evolution of knowledge. Japan offers stimulating clues on how we might regard the usefulness of computers, and these are explained. Evocative illustrations are presented, to show a direction for future developments.
series CAAD Futures
last changed 2003/11/21 15:16

_id avocaad_2001_02
id avocaad_2001_02
authors Cheng-Yuan Lin, Yu-Tung Liu
year 2001
title A digital Procedure of Building Construction: A practical project
source AVOCAAD - ADDED VALUE OF COMPUTER AIDED ARCHITECTURAL DESIGN, Nys Koenraad, Provoost Tom, Verbeke Johan, Verleye Johan (Eds.), (2001) Hogeschool voor Wetenschap en Kunst - Departement Architectuur Sint-Lucas, Campus Brussel, ISBN 80-76101-05-1
summary In earlier times in which computers have not yet been developed well, there has been some researches regarding representation using conventional media (Gombrich, 1960; Arnheim, 1970). For ancient architects, the design process was described abstractly by text (Hewitt, 1985; Cable, 1983); the process evolved from unselfconscious to conscious ways (Alexander, 1964). Till the appearance of 2D drawings, these drawings could only express abstract visual thinking and visually conceptualized vocabulary (Goldschmidt, 1999). Then with the massive use of physical models in the Renaissance, the form and space of architecture was given better precision (Millon, 1994). Researches continued their attempts to identify the nature of different design tools (Eastman and Fereshe, 1994). Simon (1981) figured out that human increasingly relies on other specialists, computational agents, and materials referred to augment their cognitive abilities. This discourse was verified by recent research on conception of design and the expression using digital technologies (McCullough, 1996; Perez-Gomez and Pelletier, 1997). While other design tools did not change as much as representation (Panofsky, 1991; Koch, 1997), the involvement of computers in conventional architecture design arouses a new design thinking of digital architecture (Liu, 1996; Krawczyk, 1997; Murray, 1997; Wertheim, 1999). The notion of the link between ideas and media is emphasized throughout various fields, such as architectural education (Radford, 2000), Internet, and restoration of historical architecture (Potier et al., 2000). Information technology is also an important tool for civil engineering projects (Choi and Ibbs, 1989). Compared with conventional design media, computers avoid some errors in the process (Zaera, 1997). However, most of the application of computers to construction is restricted to simulations in building process (Halpin, 1990). It is worth studying how to employ computer technology meaningfully to bring significant changes to concept stage during the process of building construction (Madazo, 2000; Dave, 2000) and communication (Haymaker, 2000).In architectural design, concept design was achieved through drawings and models (Mitchell, 1997), while the working drawings and even shop drawings were brewed and communicated through drawings only. However, the most effective method of shaping building elements is to build models by computer (Madrazo, 1999). With the trend of 3D visualization (Johnson and Clayton, 1998) and the difference of designing between the physical environment and virtual environment (Maher et al. 2000), we intend to study the possibilities of using digital models, in addition to drawings, as a critical media in the conceptual stage of building construction process in the near future (just as the critical role that physical models played in early design process in the Renaissance). This research is combined with two practical building projects, following the progress of construction by using digital models and animations to simulate the structural layouts of the projects. We also tried to solve the complicated and even conflicting problems in the detail and piping design process through an easily accessible and precise interface. An attempt was made to delineate the hierarchy of the elements in a single structural and constructional system, and the corresponding relations among the systems. Since building construction is often complicated and even conflicting, precision needed to complete the projects can not be based merely on 2D drawings with some imagination. The purpose of this paper is to describe all the related elements according to precision and correctness, to discuss every possibility of different thinking in design of electric-mechanical engineering, to receive feedback from the construction projects in the real world, and to compare the digital models with conventional drawings.Through the application of this research, the subtle relations between the conventional drawings and digital models can be used in the area of building construction. Moreover, a theoretical model and standard process is proposed by using conventional drawings, digital models and physical buildings. By introducing the intervention of digital media in design process of working drawings and shop drawings, there is an opportune chance to use the digital media as a prominent design tool. This study extends the use of digital model and animation from design process to construction process. However, the entire construction process involves various details and exceptions, which are not discussed in this paper. These limitations should be explored in future studies.
series AVOCAAD
email
last changed 2005/09/09 10:48

_id cdb1
authors Cornick, T., Noble, B. and Hallahan, C.
year 1991
title The Limitations of Current Working Practices on the Development of Computer Integrating Modelling in Construction
source computer Integrated Future, CIB W78 Seminar. Calibre, The Netherlands: Eindhoven University of Technology, september, 1991. Unnumbered. includes bibliography
summary For the construction Industry to improve its processes through the application computer-based systems, traditional working practices must first change to support the integrated control of design and construction. Current manual methods of practice accept the limitations of man to process a wide range of building performance and production information simultaneously. However when these limitations are removed, through the applications of computer systems, the constraints of manual methods need no longer apply. The first generation of computer applications to the Construction Industry merely modelled the divided and sequential processes of manual methods i.e. drafting, specification writing, engineering and quantity calculations, estimating, billing, material ordering data-bases and activity planning. Use of these systems raises expectations that connections within the computer between the processes modelled can actually be made and faster and more integrated information processing be achieved. 'Linking' software is then developed. The end result of this approach was that users were able to produce information faster, present it in an impressive manner but, in reality, no perceived improvement in actual building performance, production economy or efficiency was realized. A current government sponsored Teaching Company Programme with a UK design and build company is addressing the problem of how real economic benefit can be realized through improvement in, amongst other things, their existing computer applications. This work is being carried out by both considering an academic conceptual model of how 'designing for production' can be achieved in computer applications and what is immediately realizable in practice by modelling the integration of a limited number of knowledge domains to which computers are already being applied. i.e. billing from design, estimating and buying. This paper describes each area of work and how they are impacting on each other
keywords construction, building process, integration
series CADline
last changed 2003/06/02 13:58

_id e717
authors De Vries, Mark and Wagter, Harry
year 1991
title The First CAAD Package (sketch based cad)
source Computer Aided Architectural Design Futures: Education, Research, Applications [CAAD Futures ‘91 Conference Proceedings / ISBN 3-528-08821-4] Zürich (Switzerland), July 1991, pp. 497-510
summary In this paper a theory will be presented that can be used to develop a new type of CAD program. It supports architectural design and can be applied to the earliest stages of the design process. The theory is based on architectural knowledge and describes how sketched input can be used for CAAD programs. The theoretical backgrounds will be explained briefly.
series CAAD Futures
email
last changed 2003/05/16 20:58

_id ecaade2007_073
id ecaade2007_073
authors Francis, Sabu
year 2007
title Web Based Collaborative Architectural Practice Using a Fractal System
source Predicting the Future [25th eCAADe Conference Proceedings / ISBN 978-0-9541183-6-5] Frankfurt am Main (Germany) 26-29 September 2007, pp. 727-734
doi https://doi.org/10.52842/conf.ecaade.2007.727
summary I have been working on an architecture representation system in India since 1991; that markedly deviates from the need of traditional drawings as we know. Over three million square feet of work has been done that took advantage of this system as it was being developed. The system has now matured sufficiently to be put into practice as a comprehensive architectural system of practice. It takes advantage of creation of just-in-time dynamic multi-organizations that can get formed (and dismantled) over the Internet on a project to project basis. The raison d’être of the representation system is that it would expose the “source-code” (metaphorically) of any work of architecture to stakeholders, much the same way as an open-source software project exposes the internal representation to fellow developers. I believe the design of architecture must go through an “open source” process in order to produce socially responsible designs. Such a stance is explained in this paper. The paper also explains the system in detail; its mathematical basis and justifies the need for such an approach. It also explores how a collaborative practice can be put into place using the system in the context of Internet technologies.
keywords Collaborative practice, fractals, representation system
series eCAADe
email
last changed 2022/06/07 07:50

_id f85d
authors Geraedts, Rob P and Pollalis, Spiro N.
year 2001
title Remote Teaching in Design Education - Educational and Organizational Issues and Experiences
source Architectural Information Management [19th eCAADe Conference Proceedings / ISBN 0-9523687-8-1] Helsinki (Finland) 29-31 August 2001, pp. 305-310
doi https://doi.org/10.52842/conf.ecaade.2001.305
summary The Department of Real Estate and Project Management (BMVB) of the Faculty of Architecture at the Delft University of Technology has been working closely with Professor Spiro N. Pollalis of Harvard University, Graduate School of Design in Cambridge, USA since 1991. His case-based interactive seminars about the management of the design & construction process have been highly appreciated by many generations of students. In Spring 2000, Pollalis suggested to extend the scope of his involvement by introducing a remote teaching component, the subject of his research in the last few years. As Information and Communication Technology (ICT) in the Design and Construction Industry is part of his lectures, it was appropriate to provide the students with a first hand experience on the subject. In the following experiment, the teacher would remain in his office at Harvard while the interactive work and discussion sessions with 130 students in a full lecture room would take place in Delft as planned. The consequences this experiment has had for the course, for the techniques and facilities used, how teachers and students experienced these, and which conclusions and recommendations can be made, are the topics of this paper.
keywords Remote Teaching, Design & Construction Education, And ICT
series eCAADe
last changed 2022/06/07 07:51

_id 2a0e
authors Jacobs, Stephen Paul
year 1991
title The CAD Design Studio: 3D modeling as a fundamental design skill
source McGraw-Hill, New York
summary Until now, books on CAD aimed at architects have addressed the use of computer-aided design and drafting as a recording tool, a faster means of producing and storing finished working drawings-and not as an adjunctive creative tool for the design process. Without being software specific, this book will guide the professional and student architect and graphics designer in how to use the computer as an electronic modelling tool, exploring graphic and geometric forms and systems with the freedom and speed of the computer. The reader will be led through a progression of design exercises and design problems, learning how to come up with multiple solutions to a given program. Beautifully illustrated throughout, including 10 four-color CAD drawings!
series other
last changed 2003/04/23 15:14

_id 7508
authors Montgomery, D.C.
year 1991
title Design and Analysis of Experiments
source John Wiley, Chichester
summary Learn How to Achieve Optimal Industrial Experimentation Through four editions, Douglas Montgomery has provided statisticians, engineers, scientists, and managers with the most effective approach for learning how to design, conduct, and analyze experiments that optimize performance in products and processes. Now, in this fully revised and enhanced Fifth Edition, Montgomery has improved his best-selling text by focusing even more sharply on factorial and fractional factorial design and presenting new analysis techniques (including the generalized linear model). There is also expanded coverage of experiments with random factors, response surface methods, experiments with mixtures, and methods for process robustness studies. The book also illustrates two of today's most powerful software tools for experimental design: Design-Expert(r) and Minitab(r). Throughout the text, You'll find output from these two programs, along with detailed discussion on how computers are currently used in the analysis and design of experiments. You'll also learn how to use statistically designed experiments to: * Obtain information for characterization and optimization of systems * Improve manufacturing processes * Design and develop new processes and products * Evaluate material alternatives in product design * Improve the field performance, reliability, and manufacturing aspects of products * Learn how to conduct experiments effectively and efficiently Other important textbook features: * Student version of Design-Expert(r) software is available. * Web site (www.wiley.com/college/montgomery) offers supplemental text material for each chapter, a sample syllabus, and sample student projects from the author's Design of Experiments course at Arizona State University.
series other
last changed 2003/04/23 15:14

_id f14c
authors Sariyildiz, Sevil
year 1991
title Conceptual Design by Means of Islamic-Geometric-Patterns within a CAAD-Environment
source Delft University of Technology
summary The starting point in this research was to develop a 3D grammar theory on top of existing 2D Islamic-geometric-patterns, trying to rescue their fundamental geometry contents to be applied in contemporary architecture without compromising any architectural style. As it is self evident the architectural design process consists of clearly distinct stages namely conceptual design, materialisation and further completion. A this conceptual stage the innovative item of the research deals with pattern grammars on 3D complex geometrical patterns, considering them as polyhedra and polytopes, for their use as an underlayer to a concept design, like architects use 2D rectangular and triangular grids by the conventional way. Handling these complex 3D patterns requires a special environment which is possible with CAAD. Within the CAAD environment, the handling of these complex patterns is easily done by means of 3D tools, because the 3D tools permit the user to make any possible manipulations and geometrical transformations in an easier way in space. To a geometrical patterns, there is some attention paid during the last 50 years by some scholars. The most complex geometrical patterns are highly developed in Islamic architecture because it is forbidden in Muslim religion to use man's portraits or sculptures of human beings in the religious buildings. All these approaches to complex patterns are analysed and studied as 2D elements. The question was how could we consider them in 3rd dimensions and use them instead of 2D underlayer, as 3D underlayers in the conceptual phase of the CAAD design. Pattern grammar is a generally employable aid (underlying pattern) for conceptual and material designs. On the basis of rules of symmetry and substitution, ordering principles have been worked out, which can be used for formal design methods as well as detailing systems (e.g. modular coordination). Through the realization of a pattern grammar a wider range of underlying patterns can be offered and a choice from these can be made in a more fundamental manner. At a subsequent stage the collection of "empty boxes" can be filled with (architectural) elements in such a way that another option is created between either filling up the boxes completely, filling them partly, or filling them in such a way that they overflow. It is self-evident that underlying patterns can also be used for details and decoration in a design. Concerning the materialisation of the concept design, within the 3D CAAD environment, substitution methods are partially developed. Further theoretical developments concerning the materialisation phase constantly backed up through feed-back with specialist matters (such as e.g. by means of expert systems, decision-support systems), must be worked out. As feed-back of the research, the possibilities of the design with 3D patterns have been tested and the procedures are explained. (*) Working with 3D patterns gives a designer more inspirations to develop new ideas and new concepts and gives the opportunity to handle the complexity. (*) The formal, structural and symmetrical qualities of geometrical patterns has a positive influence on the industrialisation of the building components. (*) Working with 3D tools which are able to handle complex geometry have a result because of the accuracy of the information, that there has hardly been a mistake made during the preparation and the assembly of the building components. This has also positive results concerning the financial aspects of the building process.
series thesis:PhD
email
last changed 2003/02/12 22:37

_id ddss9483
id ddss9483
authors Shyi, Gary C.-W. and Huang, Tina S.-T.
year 1994
title Constructing Three-Dimensional Mental Models from Two-Dimensional Displays
source Second Design and Decision Support Systems in Architecture & Urban Planning (Vaals, the Netherlands), August 15-19, 1994
summary In the present study we adopted the tasks and the experimental procedures used in a recent series of study by Cooper (1990, 1991) for the purpose of examining how we utilized two-dimensional information in a line-drawing of visual objects to construct the corresponding three-dimensional mental structure represented by the 2-D displays. We expected that the stimulus materials we used avoided some of the problems that Cooper's stimuli had, and with that we examined the effect of complexity on the process of constructing 3-D models from 2-D displays. Such a manipulation helps to elucidate the difficulties of solving problems that require spatial abilities. We also investigated whether or not providing information representing an object viewed from different standpoints would affect the construction of the object's 3-D model. Some researchers have argued that 3-D models, once constructed, should be viewer-independent or viewpoint-invariant, while others have suggested that 3-D models are affected by the viewpoint of observation. Data pertinent to this issue are presented and discussed.
series DDSS
last changed 2003/08/07 16:36

_id 2c7b
authors Stenvert, Ronald
year 1993
title The Vector-drawing as a Means to Unravel Architectural Communication in the Past
source [eCAADe Conference Proceedings] Eindhoven (The Netherlands) 11-13 November 1993
doi https://doi.org/10.52842/conf.ecaade.1993.x.q9a
summary Unlike in painting, in architecture one single person never controls the whole process between conception and realization of a building. Ideas of what the building will eventually look like, have to be conveyed from patron to the actual builders, by way of drawings. Generally the architect is the key-figure in this process of communication of visual ideas. Nowadays many architects design their new buildings by using computers and Computer-Aided (Architectural) Design programs like AutoCad and VersaCAD. Just like traditional drawings, all these computer drawings are in fact vector-drawings; a collection of geometrical primitives like lines, circle segments etc. identified by the coordinates of their end points. Vector-based computer programs can not only be used to design the future, but also as a means to unravel the architectural communication in the past. However, using the computer as an analyzing tool for a better comprehension of the past is not as simple as it seems. Historical data from the past are governed by unique features of date and place. The complexity of the past combined with the straightforwardness of the computer requires a pragmatic and basic approach in which the computer acts as a catalytic agent, enabling the scholar to arrive manually at his own - computer-assisted - conclusions. From this it turns out that only a limited number of projects of a morphological kind are suited to contribute to new knowledge, acquired by the close-reading of the information gained by way of meaningful abstraction. An important problem in this respect is how to obtain the right kind of architectural information. All four major elements of the building process - architect, design, drawing and realization - have their own different and gradually shifting interpretations in the past. This goes especially for the run-of-the-mill architecture which makes up the larger part of the historical urban environment. Starting with the architect, one has to realize that only a very limited part of mainstream architecture was designed by architects. In almost all other cases the role of the patron and the actual builder exceeds that of the architect, even to the extent that they designed buildings themselves. The position of design and drawing as means of communication also changed in the past. Until the middle of the nineteenth century drawings were not the chief means of communication between architects and builders, who got the gist of the design from a model, or, encountering problems, simply asked the architect or supervisor. From the nineteenth century onwards the use of drawings became more common, but almost never represented the building entirely "as built". In 1991 I published my Ph.D. thesis: Constructing the past: computerassisted architectural-historical research: the application of image-processing using the computer and Computer-Aided Design for the study of the urban environment, illustrated by the use of treatises in seventeenth-century architecture (Utrecht 1991). Here, a reconstruction of this historical communication process will be presented on the basis of a project studying the use of the Classical orders as prescribed in various architectural treatises, compared to the use of the orders in a specific group of still existing buildings in The Netherlands dating from the late sixteenth and entire seventeenth century. Comparisons were made by using vector-drawings. Both the illustrations in the the treatises and actual buildings were "translated" into computer-drawings and then analyzed.

series eCAADe
last changed 2022/06/07 07:50

_id b5be
authors Stok, Leon
year 1991
title Architectural synthesis and optimization of digital systems
source Eindhoven University of Technology
summary High level synthesis means going from an functional specification of a digits-system at the algorithmic level to a register transfer level structure. Different appli-cations will ask for different design styles. Despite this diversity in design styles many tasks in the synthesis will be similar. There is no need to write a new synthesis system for each design style. The best way to go seems a decomposition of the high level synthesis problems in several well defined subproblems. How the problem is decomposed depends heavily on a) the type of network architecture chosen, b) the constraints applied to the design and c) on the functional description itself. From this architecture style, the constraints and the functional description a synthesis scheme can be derived. Once this scheme is fixed, algorithms can be chosen which fit into this scheme and solve the subproblems in a fast and, when possible, optimal way. To support such a synthesis philosophy, a framework is needed in which all design information can be stored in a unique way during the various phases of the design process. This asks for a design data base capable of handling all design information with a formally defined interface to all design tools. This thesis gives a formal way to describe both the functional representation, the register transfer level structure and the controller and the relations between all three of them. Special attention has been paid to the efficient representation of mutual exclusive operations and array accesses. The scheduling and allocation problems are defined as mappings between these formal representations. Both the existing synthesis algorithms and the new algorithms described in this thesis fit into this framework. Three new allocation algorithms are presented in this thesis: an algorithm for optimal register allocation in cyclic data flow graphs, an exact polynomial algorithm to do the module allocation and a new scheme to minimize the number of interconnections during all stages of the data path allocation. Cyclic data flow graphs result from high level behavioral descriptions that contain loops. Algorithms for register allocation in high level synthesis published up till now, only considered loop free data flow graphs, When these algorithms are applied to data flow graphs with loops, unnecessary register transfer operations are introduced. A new algorithm is presented that performs a minimal register allocation and eliminates all superfluous register transfer operations. The problem is reformulated as a multicommodity network flow problem for which very efficient solutions exist. Experiments on a benchmark set have shown that in all test cases all register transfers could be eliminated at no increase in register cost. Only heuristic algorithms appeared in literature to solve the module allocation problem. The module allocation problem is usually defined as a clique cover problem on a so-called module allocation graph. It is shown that, under certain conditions, the module allocation graph belongs to the special class of comparability graphs. A polynomial time algorithm can optimally find a clique cover of such a graph. Even when interconnect weights are taken into account, this can be solved exactly. This problem can be transformed into a maximal cost network flow problem, which can be solved exactly in polynomial time. An algorithm is described which solves the module allocation problem with interconnect weights exactly, with a complexity O(kn2), where n is the number of operations In previous research, interconnection was optimized when the module allocation for the operations and the register allocation for the variables already had been done. However, the amount of multiplexing and interconnect are crucial factors to both the delay and the area of a circuit. A new scheme is presented to minimize the number of interconnections during the data path allocation. This scheme first groups all values based on their read and write times. Values belonging to the same group can share a register file. This minimizes the number of data transfers with different sources and destinations. Secondly, registers are allocated for each group separately. Finally the interconnect allocation is done. During the interconnect allocation, the module allocation is determined. The value grouping is based on edge coloring algorithms providing a sharp upper bound on the number of colors needed two techniques: splitting read and write phases of values and introducing serial (re-)write operations for the same value, make that even more efficient exact edge coloring algorithms can be used. It is shown that when variables are grouped into register files and operations are assigned to modules during the interconnection minimization, significant savings (20%) can be obtained in the number of local interconnections and the amount of global interconnect, at the expense of only slightly more register area.
keywords Digital Systems; Digital Systems
series thesis:PhD
email
last changed 2003/02/12 22:37

_id 85c5
authors Strauss, Wolfgang
year 1991
title Organization Principles in Virtual Space - Digital Casa in Media City
source Experiences with CAAD in Education and Practice [eCAADe Conference Proceedings] Munich (Germany) 17-19 October 1991
doi https://doi.org/10.52842/conf.ecaade.1991.x.o4m
summary Omitting the "virtual": the organization of the space - that is architecture. How the design process itself has been changed by the new media, is the topic of this discussion - the process of designing in its penetration and extension into other techniques and media, for example video montage or image data banks. The process of designing becomes an electronic working of images differing substantially from the traditional process by the employed electronic devices.
series eCAADe
last changed 2022/06/07 07:50

_id 83b4
authors Tan, Milton
year 1991
title Themes for Schemes: Design Creativity as the Conceptualization, Transformation, and Representation of Emergent Forms
source Harvard University, Graduate School of Design
summary Architects, graphic designers, and others frequently develop designs by picking out and transforming subshapes of two-dimensional or three-dimensional shapes. Shape grammars formalize this aspect of design by specifying rules of the form $a /to b$: the left-hand side a describes a type of subshape that may be picked out, while the right-hand side b describes what that type of subshape may become. Designs in the language specified by a shape grammar are derived by recursively applying the shape transformation rules to a starting shape. To apply a shape-transformation rule automatically, a computer system, must have the capacity to recognize instances of the type of subshape specified on the left-hand side of the rule. Sometimes such instances are explicitly input by the designer, and explicitly represented in a data structure: in this case, recognition is a relatively straightforward task. But there may also be 'emergent' instances that were not explicitly input, and are only indirectly represented in the data structure. These emergent instances are potentially numerous, and may be extremely difficult to discover. This thesis focuses on mechanisms for picking out and transforming subshapes. The first three chapters place the issue in its broadest context by arguing that different designers--bringing different knowledge and attitudes to the task--will pick out and pay attention to different subshapes in a drawing. This contention is supported by introducing some of the relevant literature on perception, problem-solving, and creativity. Chapter 4 introduces shape grammars to provide a more formal framework for investigating this topic. Chapter 5 describes the properties and limitations of Topdown--a computer program which supports design by applying the rules of a shape grammar, but does not provide for recognition of emergent subshapes. Chapter 6 introduces ECART, a computer program which supports efficient recognition and transformation of emergent subshapes, and demonstrates how its performance transcends that of Topdown. Examination of the results produced by ECART suggest that a designer's conceptual filter--the repertoire of subshape types that he or she can recognize in a drawing--plays a crucial role in the development of design ideas.  
keywords Computer Graphics; Computer Software; Development
series thesis:PhD
email
last changed 2003/02/12 22:37

_id bbdc
authors Tang, J.C.
year 1991
title Findings from observational studies of collaborative work
source international Joumal of Man-Machine Studies, 34(2), 143-160
summary The work activity of small groups of three to four people was videotaped and analyzed in order to understand collaborative work and to guide the development of tools to support it. The software tools we currently have are often based on a single user model. Even those that are based on multiple user models define structures of interaction that restrict fluid collaboration. We need observe how people collaborate then build software that facilitates collaboration based on those observations, giving the users the tools" that are "naturally" defined in face-to-face interaction. In this experiment small groups of people were observed in a collaborative design task using a shared drawing space. Specific features of collaborative work activity that raise design implications for collaborative technology: 1. collaborators use hand gestures to uniquely communicate significant information 2. the process of creating and using drawings conveys much information not contained in the resulting drawings 3. the drawing space is an important resource for the group in mediating their collaboration 4. there is a fluent mix of activity in the drawing space 5. the spatial orientation among the collaborators and the drawing space has a role in structuring their activity
series other
last changed 2003/04/23 15:14

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