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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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_id	728f
authors	Gross, Mark D.
year	1991
title	Grids in Design and CAD
source	Reality and Virtual Reality [ACADIA Conference Proceedings / ISBN 1-880250-00-4] Los Angeles (California - USA) October 1991, pp. 33-43
doi	https://doi.org/10.52842/conf.acadia.1991.033
summary	The grid is a useful device for expressing design rules about the placement of elements in a layout. By expressing position rules for elements in relation to a grid, a designer can systematically organize decisions in a layout design problem. Grids and placement rules offer a discipline that can help a designer work effectively to lay out complex designs, and it can also facilitate group design work. Unfortunately, computer supported drawing systems often cannot support this way of working because they lack a sufficiently rich implementation of grids. The Grid Manager module of the CoDraw program shows enhancements useful for architectural Computer Assisted Design. These enhancements would enable more effective ways of using the computer as a design tool.
series	ACADIA
email
last changed	2022/06/07 07:51

_id	2e03
authors	Diederiks, H.J. and van Staveren, R.J.
year	1991
title	Dynamic Information System for Modelling of Design Processes
source	Computer Integrated Future, CIB W78 Seminar. september, 1991
summary	Unnumbered : ill. DINAMO is a Dynamic Information System for Modelling of Design Processes. It is intended for use along with product models, data management systems and existing applications. In DINAMO a programming user can define processes. These processes are represented by graphs. The graphs are characterized by nodes and relations between nodes. Each node in a graph represents a task, and each relation can be restricted to conditions. So the way in which a process is actually being performed, that is, the actual path to be evaluated through the graph, can depend on certain conditions. Processes and functions (=software modules) are available to the user as tasks. A consuming user can activate tasks; the DINAMO system regulates the dispatch of the tasks, conform the process and function definitions. Tasks are collected on sheets; sheets are collected in a task box. A task box can be regarded as a certain environment, determined by the programming user. A consuming user can choose between the environments which are available at that moment. With the DINAMO system software and process definitions can be re-used in a simple way
keywords	design process, modeling, graphs, information, relations, software
series	CADline
last changed	2003/06/02 13:58

_id	eb51
authors	Coyne, Richard
year	1996
title	CAAD, Curriculum and Controversy
source	Education for Practice [14th eCAADe Conference Proceedings / ISBN 0-9523687-2-2] Lund (Sweden) 12-14 September 1996, pp. 121-130
doi	https://doi.org/10.52842/conf.ecaade.1996.121
summary	This paper brings some of the debate within educational theory to bear on CAAD teaching, outlining the contributions of conservatism, critical theory, radical hermeneutics and pragmatism. The paper concludes by recommending that CAAD teaching move away from conservative concepts of teaching, design and technology to integrate it into the studio. In a highly illuminating book on education theory, Shaun Gallagher (1991) outlines four current views on education that correspond to four major positions in contemporary social theory and philosophy. I will extend these categories to a consideration of attitudes to information technology, and the teaching of computing in architecture. These four positions are conservatism, critical theory, radical hermeneutics, and pragmatism. I will show how certain issues cluster around them, how each position provides the focus of various discursive practices, or intellectual conversations in contemporary thinking, and how information technology is caught up in those conversations. These four positions are not "cognitive styles," but vigorously argued domains of debate involving writers such as Gadamer, Habermas and Derrida about the theory of interpretation. The field of interpretation is known as hermeneutics, which is concerned less with epistemology and knowledge than with understanding. Interpretation theory applies to reading texts, interpreting the law, and appreciating art, but also to the application of any practical task, such as making art, drawing, defining and solving problems, and design (Coyne and Snodgrass, 1995). Hermeneutics provides a coherent focus for considering many contemporary issues and many domains of practice. I outline what these positions in education mean in terms of CAAD (computer-aided architectural design) in the curriculum.
series	eCAADe
email
more	http://www.caad.ac.uk/~richard
last changed	2022/06/07 07:56

_id	01c8
authors	Gross, Mark D.
year	1991
title	Programming 2-Way Constraints in CODRAW
source	1991. [8] p. : ill. includes bibliography
summary	Constraints based drawing programs require users to understand and manage relationships between drawing elements. By establishing constraint relationship among elements the user effectively programs the drawing's behavior. This programming task requires a more sophisticated visual interface than conventional drawing programs provide. Users must have available - in a convenient format - information about the structure of the constraints that determine the drawing's interactive edit behavior. This format must support editing and debugging. CoDraw is a constraint based drawing program that can be interactively extended by its users. This paper describes the CoDraw program and its programming interface
keywords	constraints, drafting, user interface
series	CADline
last changed	2003/06/02 10:24

_id	2d77
authors	Korte, Michael
year	1991
title	CASOB - Simultaneous Surveying and Drawing
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.t7p
summary	Accurate planning and economical building within an existing structure require a complex building analysis based upon detailed scale plans. Work has shown unsatisfactory of measuring tools: (1.) Recording of measurements with meterrule and measuring tape often results in mistakes and wasted time. Since the data is not digitalized the measurements cannot be used by a CAD system. (2.) Commercially available CAD software is made only for new planning but not for planning with an existing structure. Up till now architects who predominantly work with existing structures were not able to take advantage of products in the software- and hardware market which would satisfy their needs. The problems already begin with the search for appropriate tools for the surveying of existing structures and the simplest possible transfer of the data to a CAD System. There is an increased demand for quality surveying of existing structures. In Germany, far more than 60 % of all construction planning is related to existing structures. Due to the special situation in the five new states this percentage will grow significantly. Other countries will find themselves in a similar situation. A large number of precise and analytical surveys of existing structures will be needed in a relative short time. Time pressure and stress factors at construction sites call for quality planning and economical construction which can only be accomplished with reliable and exact surveying of structures. Frustrating experiences in the field have led me to develop systems for the surveying of existing structures. With CASOB (Computer Aided Surveying of Buildings) we have a tool today that simultaneously surveys and creates a CAD compatible drawing.
series	eCAADe
last changed	2022/06/07 07:50

_id	2e3b
authors	Kvan, Thomas and Kvan, Erik
year	1997
title	Is Design Really Social
source	Creative Collaboration in Virtual Communities 1997, ed. A. Cicognani. VC'97. Sydney: Key Centre of Design Computing, Department of Architectural and Design Science, University of Sydney, 8 p.
summary	There are many who will readily agree with Mitchell’s assertion that “the most interesting new directions (for computer-aided design) are suggested by the growing convergence of computation and telecommunication. This allows us to treat designing not just as a technical process... but also as a social process.” [Mitchell 1995]. The assumption is that design was a social process until users of computer-aided design systems were distracted into treating it as a merely technical process. Most readers will assume that this convergence must and will lead to increased communication between design participants; that better social interaction leads to be better design. The unspoken assumption appears to be that putting the participants into an environment with maximal communication channels will result in design collaboration. The tools provided; therefore; must permit the best communication and the best social interaction. We think it essential to examine the foundations and assumptions on which software and environments are designed to support collaborative design communication. Of particular interest to us in this paper is the assumption about the “social” nature of design. Early research in computer-assisted design collaborations has jumped immediately into conclusions about communicative models which lead to high-bandwidth video connections as the preferred channel of collaboration. The unstated assumption is that computer-supported design environments are not adequate until they replicate in full the sensation of being physically present in the same space as the other participants (you are not there until you are really there). It is assumed that the real social process of design must include all the signals used to establish and facilitate face-to-face communication; including gestures; body language and all outputs of drawing (e.g. Tang [1991]). In our specification of systems for virtual design communities; are we about to fall into the same traps as drafting systems did?
keywords	CSCW; Virtual Community; Architectural Design; Computer-Aided Design
series	other
email
last changed	2002/11/15 18:29

_id	9e4e
authors	Minneman, S. and Bly, S.
year	1991
title	Managing a Trois: a study of a multi-user drawing tool in distributed design work
source	Proceedings of the Conference on Computer Human Interaction (CHI) '91, pp. 217-224,1991
summary	A multi-user drawing tool was used by participants in a distributed design exercise conducted in a multi-media working environment. The goal of the study was to explore how observations from our earlier studies of shared drawing in two-person design activity would hold up when three participants worked together. Additionally, the study provided opportunities to contrast video/audio connections with audio-only connections and to discover new behaviors that emerge in the use of new technologies. Participants successfully used the shared drawing system with no observed difficulties attributable to the addition of a third user. Audio-only connections appeared to adequately suppofi this work activity, but details of the participants' interactions in the exercise raised questions that deserve further study. Finally, observations suggest that drawing tools such as the one reported here may offer support for alternative forms of participation in collaborative work.
series	other
last changed	2003/04/23 15:50

_id	f2e8
authors	Norman, Richard B.
year	1991
title	Real and Un-real Color
source	Reality and Virtual Reality [ACADIA Conference Proceedings / ISBN 1-880250-00-4] Los Angeles (California - USA) October 1991, pp. 45-52
doi	https://doi.org/10.52842/conf.acadia.1991.045
summary	Drawings exist for the communication of ideas. They are the containers of mankind's visual dreams and embody all of the hopes, the aspirations, and intentions of their creators. The act of drawing is itself an expression of the desire for a world that is better than what already exists. The appearance of a new drawing media does not change that purpose, it only presents new and stimulating methods of communication, better ways of conveying ideas. In ideal terms the design of a building requires a holistic procedure, one where the entire edifice is created in a single instant. The building must seem totally compete and be universally understood in order that it can be accepted, detailed, structured, and priced. This is of course not possible; there are too many aspects of architecture that are not thought about at the moment of creation. The process of design is continuous and moves from general to specific; any drawing media, to be useful, must accommodate this continuity. Completeness, where complete thought does not exist, cannot be achieved by the pursuit of reality on the computer. There are many unknowns that prohibit the creation of "real" pictures-unless one makes design assumptions that prudent process should not accept.
series	ACADIA
email
last changed	2022/06/07 07:58

_id	cf2009_poster_43
id	cf2009_poster_43
authors	Oh, Yeonjoo; Ellen Yi-Luen Do, Mark D Gross, and Suguru Ishizaki
year	2009
title	Delivery Types And Communication Modalities In The Flat-Pack Furniture Design Critic
source	T. Tidafi and T. Dorta (eds) Joining Languages Cultures and Visions: CAADFutures 2009 CD-Rom
summary	A computer-based design critiquing system analyzes a proposed solution and offers critiques (Robbins 1998). Critiques help designers identify problems as well as opportunities to improve their designs. Compared with human critics, today’s computer-based critiquing systems deliver feedback in quite restricted manner. Most systems provide only negative evaluations in text; whereas studio teachers critique by interpreting the student’s design, introducing new ideas, demonstrating and giving examples, and offering evaluations (Bailey 2004; Uluoglu 2000) using speech, writing, and drawing to communicate (Anthony 1991; Schön 1983). This article presents a computer-based critiquing system, Flat-pack Furniture Design Critic (FFDC). This system supports multiple delivery types and modalities, adapting the typical system architecture of constraint-based intelligent tutors (Mitrovic et al. 2007).
keywords	Critiquing system, design critiquing
series	CAAD Futures
type	poster
email
last changed	2009/07/08 22:12

_id	9ad2
authors	Owen, J.C.
year	1991
title	Algebraic Solution for Geometry from Dimensional Constraints
source	ACM Symp. Found. of Solid Modeling, Austin TX, pp. 397-407
summary	We investigate general configurations of distance and angle dimensions between points, lines and circles on a plane. A simple graphical representation is described for the system of coupled ctuadratic equations which results from treating the geometries as variables and the dimensions as defining equations. For many configurations of practical interest we show that these equations are poorly suited to numerical solution. We describe an algorithm for computing the solution to a subset of all possible configurations of geometry and dimensions using purely algebraic methods (in fact the usual arithmetic operations plus square roots). We show that this algorithm solves for all configurations of a practically useful type and that it solves for any configuration which can in principle be solved using these algebraic operations. Specifically, we use the Galois theory of equations to show that the following statements are equivalent. 1. The geometry can be constructed in principle on a drawing board using a ruler and compasses. 2. The coordinates of the geometries can be computed algebraically using only arithmetic operations plus square root. 3. The coordinates of the geometries lie in a normal field extension over the dimension values of degree 2n for some n. 4. For general (i.e. algebraically independent) dimension values the algorithm described will compute the geometries. We also describe a working implementation of the algorithm and describe some extensions to the basic ideaa which are necessary to make it a practically useful way to specify geometry by means of dimensional constraints.
series	other
last changed	2003/04/23 15:50

_id	a233
authors	Rosenman, M.A., Gero, J.S. and Oxman, R.E.
year	1991
title	What's in a Case: The Use of Case Bases, Knowledge Bases, and Databases in Design
source	Computer Aided Architectural Design Futures: Education, Research, Applications [CAAD Futures ‘91 Conference Proceedings / ISBN 3-528-08821-4] Zürich (Switzerland), July 1991, pp. 285-300
summary	Design experience can be classified into generalized or compiled knowledge and specific knowledge. Generalized design knowledge has been introduced into computer-aided design in the form of rules, frames and more recently, design prototypes. Case-based reasoning is a well-defined paradigm in artificial intelligence and has obvious scope for its use in design reasoning. This paper explores case-based reasoning in design and argues for the integration of both specific and generalized design knowledge. This integration allows for characterizing what is in a case by drawing upon the schema developed for design prototypes. Finally, the paper argues that the addition of precedent knowledge, in the form of case bases, to knowledge bases and CAD databases will further extend the experience-based capabilities of design systems.
series	CAAD Futures
email
last changed	2003/05/16 20:58

_id	82c6
authors	Sabater, Txatxo
year	1991
title	Learning from Volume Processing
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.o9t
summary	We will expose a kind of chosen curriculum about the activities we have been working on, basically at the Politechnical University of Barcelona Valles School of Architecture. Our activities, in the realm of Apple Macintosh, involve undergraduate students and a Master degree as well. The way we use graphic computers and 3D software has been formulated gradually through a continuous and progressive use. Dedicating work with Apple Macintosh computers doesn't concern to teaching drawing programmes, but we try to "normalize" its use. How? Integrating it in different tasks and suggesting its use in a range of programmes. And, sometimes, letting the visual transcriptions suggest new arguments. The visual system of values developed by the Modernists (now history) and through the mass media, especially photography, cinema, video, are, nowadays, part of our visual language.
series	eCAADe
last changed	2022/06/07 07:50

_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	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	2344
authors	White, Richard
year	1991
title	Recognizing Structures: Some Problems in Reasoning with Drawings
source	Computer Aided Architectural Design Futures: Education, Research, Applications [CAAD Futures ‘91 Conference Proceedings / ISBN 3-528-08821-4] Zürich (Switzerland), July 1991, pp. 381-394
summary	This paper describes work on our current project aimed at developing a generalized system for performing automated reasoning tasks in various domains, using information extracted from drawings. It briefly describes the MOLE representation system, a frame-like formalism which can be used to build both description and inheritance hierarchies. The use of MOLE for representing graphical objects as well as the objects they represent is also described.The paper goes on to discuss some of the problems faced in the development of systems which can perform reasoning tasks on such representations. In particular, problems arising from the need to map the structures required by the application domain to the drawing description are outlined and a model which adapts existing Artificial Intelligence (AI) techniques to solve these problems is proposed.
series	CAAD Futures
last changed	1999/04/07 12:03

_id	43
authors	Horacio A. Torres. Lic. Geog. Cesira Morano. Guillermo Tella
year	1998
title	Utilización de un Sig Para la Formulacion de un Diagnostico Socioterritorial de la Ciudad de Buenos Aires (Use of a GIS for the Formulation of a Socio-territorial Diagnostic of the City of Buenos Aires)
source	II Seminario Iberoamericano de Grafico Digital [SIGRADI Conference Proceedings / ISBN 978-97190-0-X] Mar del Plata (Argentina) 9-11 september 1998, pp. 324-331
summary	The use of a GIS to assist the elaboration of a socioterritorial diagnosis of the City of Buenos Aires. This paper is based on the result of two research projects sponsored by the University of Buenos Aires (Project AR01 0 and Project Cl-94). From the beginning of 1998 onwards these results have been applied to the development of a "socio-territorial diagnosis" of the City of Buenos Aires, an applied research project funded by the Government of the City of Buenos Aires and carried out by the Facultad de Arquitectura, Diseho y Urbanismo, Universidad de Buenos Aires (Research Unit: PROHAB). The main goal of the analysis was the identification of the spatial distribution pattern of of the selected variables, directed to the delimitation of "social areas". The facilities provided by the GIS allowed us to perform this task in an exploratory manner. An analysis of the 3405 census tracts of the City of Buenos Aires (the central part of the agglomeration) is presented here. A great number of indices were constructed based on variables of the Argentine National Census of Population and Housing referred to housing conditions, housing type, provision of services, origin of the population, educational level, etc. This paper describes the various steps necessary for the application of a GIS, including the digitizing of the cartographic base and the statistical elaboration of the census information (provided by the INDEC in magnetic medium). A colour cartographic output that can be considered a first approximation of the "social map" of the city in 1991 is presented.
series	SIGRADI
email
last changed	2016/03/10 09:53

_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	a620
authors	Asanowicz, Alexander
year	1991
title	Unde et Quo
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.t1s
summary	To begin with, I would like to say a few words about the problem of alienation of modern technologies which we also inevitably faced while starting teaching CAD at our department. Quite often nowadays a technology becomes a fetish as a result of lack of clear goals in human mind. There are multiple technologies without sense of purpose which turned into pure experiments. There is always the danger of losing purposeness and drifting toward alienation. The cause of the danger lies in forgetting about original goals while mastering and developing the technology. Eventually the original idea is ignored and a great gap appears between technical factors and creativity. We had the danger of alienation in mind when preparing the CAAD curriculum. Trying to avoid the tension between technical and creative elements we agreed not to introduce CAD too soon then the fourth year of studies and continue it for two semesters. One thing was clear - we should not teach the technique of CAD but how to design using a computer as a medium. Then we specified projects. The first was called "The bathroom I dream of" and meant to be a 2D drawing. The four introductory meetings were in fact teaching foundations of DOS, then a specific design followed with the help of AutoCAD program. In the IX semester, for example, it was "A family house" (plans, facades, perspective). "I have to follow them - I am their leader" said L.J. Peter in "The Peter's Prescription". This quotation reflects exactly the situation we find ourselves in teaching CAAD at our department. It means that ever growing students interest in CAAD made us introduce changes in the curriculum. According to the popular saying, "The more one gets the more one wants", so did we and the students feel after the first semester of teaching CAD. From autumn 1991 CAAD classes will be carried from the third year of studying for two consecutive years. But before further planning one major steep had to be done - we decided to reverse the typical of the seventies approach to the problem when teaching programming languages preceded practical goals hence discouraging many learners.
series	eCAADe
email
last changed	2022/06/07 07:50

_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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