Cumincad : CUMINCAD Papers : Search Results

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	4418
authors	Franklin, Randolph, Wu, Peter, Y. F. and Samaddar, Sumitro (et al)
year	1986
title	Prolog and Geometry Projects
source	IEEE Computer Graphics and Applications. November, 1986. vol. 6: pp. 46-55 : ill. includes bibliography
summary	Prolog is a useful tool for geometry and graphics implementations because its primitives, such as unification, match the requirements of many geometric algorithms. During the last two years, programs have been implemented to solve several problems in Prolog, including a subset of the Graphical Kernel System, convex-hull calculation, planar graph traversal, recognition of groupings of objects, Boolean combinations of polygons using multiple precision rational numbers, and cartographic map overlay. Certain paradigms or standard forms of geometric programming in Prolog are becoming evident. They include applying a function to every element of a set, executing a procedure so long as a certain geometric pattern exists, and using unification to propagate a transitive function. This article describes the experiences, including paradigms of programming that seem useful, and finally lists those considered as the advantages and disadvantages of Prolog
keywords	geometric modeling, computer graphics, PROLOG, programming
series	CADline
last changed	2003/06/02 13:58

_id	28d8
authors	Sarnak, Neil and Tarjan, Robert E.
year	1986
title	Planar Point Location Using Persistent Search Trees
source	Communications of the ACM July, 1986. vol. 29: pp. 669-679 : ill. includes bibliography.
summary	A classical problem in computational geometry is the planar point location problem. This problem calls for preprocessing a polygonal subdivision of the plane defined by n line segments so that, given a sequence of points, the polygon containing each point can be determined quickly on-line. Several ways of solving this problem in O(log n) query time and O(n) space are known, but they are all rather complicated. The authors propose a simple O(log n) query-time, O(n) space solution, using persistent search trees. A persistent search tree differs from an ordinary search tree in that after an insertion or deletion, the old version of the tree can stillÔ h)000*°° ÔŒ be accessed. A persistent form of binary search tree that supports insertions and deletions in the present and queries in the past is developed. The time per query or update is O(log m), where m is the total number of updates, and the space needed is O(1) per update. The planar point location algorithm is an immediate application of this data structure. The structure also provides an alternative to Chazelle's 'hive graph' structure, which has a variety of applications in geometric retrieval
keywords	search, data structures, algorithms, point inclusion, computational geometry
series	CADline
last changed	2003/06/02 13:58

_id	0f76
authors	Balachandran, M. B. and Gero, John S.
year	1986
title	Knowledge-based Design Optimization
source	IAAI'86 Conference. 1986. pp. i:4:1-14
summary	CADLINE has abstract only. Optimization is a well understood process in design domains. A designer formulates the design problem as a single criterion or multicriteria optimization problem and then selects an appropriate optimization algorithm to search for the optimal values for the design variables. The formulation and algorithm selection procedures have been considered to be activities which relied on substantive human knowledge. This paper describes a computer system, OPTIMA, which formulates design optimization problems from a pseudo-English description into canonical algebraic expressions. It then recognizes the formulation and selects appropriate algorithm(s) for their solutions. Finally, it runs the selected algorithm(s) and sends the results to the original descriptions. Areas of expert knowledge involved in carrying out the above tasks are identified. Such knowledge is explicitly encoded in the systems. The basic philosophy and key features of the system are described and are illustrated by examples
keywords	algorithms, expert systems, knowledge base, design, optimization, structures, engineering
series	CADline
email
last changed	2003/06/02 13:58

_id	ed51
authors	Bergeron, Philippe
year	1986
title	A General Version of Crow's Shadow Volumes
source	IEEE Computer Graphics and Applications September, 1986. vol. 6: pp. 17-28 : col. ill. includes bibliography.
summary	In 1977 Frank Crow introduced a new class of algorithms for the generation of shadows. His technique, based on the concept of shadow volumes, assumes a polygonal database and a constrained environment. For example, polyhedrons must be closed, and polygons must be planar. This article presents a new version of Crow's algorithm, developed at the Universite de Montreal, which attempts a less constrained environment. The method has allowed the handling of both open and closed models and nonplanar polygons with the viewpoint anywhere, including any shadow volume. It does not, however, sacrifice the essential features of Crow's original version: penetration between polygons is allowed, and any number of light sources can be defined anywhere in 3D space, including the view volume and any shadow volume. The method has been used successfully in the film Tony de Peltrie and is easily incorporated into an existing scan-line, hidden-surface algorithm
keywords	algorithms, shadowing, polygons, computer graphics
series	CADline
last changed	1999/02/12 15:07

_id	a6f1
authors	Bridges, A.H.
year	1986
title	Any Progress in Systematic Design?
source	Computer-Aided Architectural Design Futures [CAAD Futures Conference Proceedings / ISBN 0-408-05300-3] Delft (The Netherlands), 18-19 September 1985, pp. 5-15
summary	In order to discuss this question it is necessary to reflect awhile on design methods in general. The usual categorization discusses 'generations' of design methods, but Levy (1981) proposes an alternative approach. He identifies five paradigm shifts during the course of the twentieth century which have influenced design methods debate. The first paradigm shift was achieved by 1920, when concern with industrial arts could be seen to have replaced concern with craftsmanship. The second shift, occurring in the early 1930s, resulted in the conception of a design profession. The third happened in the 1950s, when the design methods debate emerged; the fourth took place around 1970 and saw the establishment of 'design research'. Now, in the 1980s, we are going through the fifth paradigm shift, associated with the adoption of a holistic approach to design theory and with the emergence of the concept of design ideology. A major point in Levy's paper was the observation that most of these paradigm shifts were associated with radical social reforms or political upheavals. For instance, we may associate concern about public participation with the 1970s shift and the possible use (or misuse) of knowledge, information and power with the 1980s shift. What has emerged, however, from the work of colleagues engaged since the 1970s in attempting to underpin the practice of design with a coherent body of design theory is increasing evidence of the fundamental nature of a person's engagement with the design activity. This includes evidence of the existence of two distinctive modes of thought, one of which can be described as cognitive modelling and the other which can be described as rational thinking. Cognitive modelling is imagining, seeing in the mind's eye. Rational thinking is linguistic thinking, engaging in a form of internal debate. Cognitive modelling is externalized through action, and through the construction of external representations, especially drawings. Rational thinking is externalized through verbal language and, more formally, through mathematical and scientific notations. Cognitive modelling is analogic, presentational, holistic, integrative and based upon pattern recognition and pattern manipulation. Rational thinking is digital, sequential, analytical, explicatory and based upon categorization and logical inference. There is some relationship between the evidence for two distinctive modes of thought and the evidence of specialization in cerebral hemispheres (Cross, 1984). Design methods have tended to focus upon the rational aspects of design and have, therefore, neglected the cognitive aspects. By recognizing that there are peculiar 'designerly' ways of thinking combining both types of thought process used to perceive, construct and comprehend design representations mentally and then transform them into an external manifestation current work in design theory is promising at last to have some relevance to design practice.
series	CAAD Futures
email
last changed	2003/11/21 15:16

_id	4e59
authors	Koparkar, P. A. and Mudur, S.P.
year	1986
title	Generation of Continuous Smooth Curves Resulting from Operations on Parametric Surface Patches
source	Computer Aided Design. May, 1986. pp. 193-206 : ill. includes bibliography
summary	In recent years a number of techniques based on the subdivision principle have been suggested for detecting the curves resulting from the intersection of two parametrically defined surface patches. Silhouette curves of surfaces can also be detected using analogous techniques. Usually the output is a set of pixels or line segments which form the complete curve, though not necessarily in an ordered manner. This paper presents data structures for maintaining the result of subdivision, and algorithms for tracing the curves in a continuous fashion. Using a few iterations of the Newton-Raphson technique the curve points may be refined to any required precision. For each point on the curve the nonlinear equations are chosen by looking at the local topological nature of the curve so as to guarantee convergence of the Newton-Raphson technique in one or two iterations
keywords	curved surfaces, parametrization, curves, intersection, relaxation, geometric modeling, computational geometry
series	CADline
last changed	2003/06/02 14:41

_id	6728
authors	Rossignac, Jaroslaw R. and Requicha, Aristides A. G.
year	1986
title	Depth- Buffering Display Techniques for Constructive Solid Geometry
source	IEEE Computer Graphics and Applications. September, 1986. vol. 6: pp. 29-39 : ill. some col. includes bibliography
summary	Solid modelers based on constructive solid geometry (CSG) typically generate shaded displays directly from CSG by using ray-casting techniques, which do not require information on the faces, edges, and vertices that bound a solid. This article describes an alternative - a simple new algorithm based on a depth-buffering or z-buffering approach. The z- buffer display algorithm operates directly on CSG, does not require explicit boundary data, and is easier to implement than ray casting. Ray-casting and z-buffering algorithms have comparable performances, but z-buffering is often faster for objects with complex surfaces, because it avoids expensive curve/surface intersection calculations. Because of their simplicity, depth-buffering algorithms for CSG are well- suited to hardware implementations, and may lead to machines simpler than those now being built for ray casting
keywords	geometric modeling, CSG, display, computer graphics
series	CADline
last changed	2003/06/02 13:58

_id	04dd
authors	Zozaya-Gorostiza and Hendrickson, Carlos and Chris
year	1986
title	A Network Representation and Algorithm for Task Planning
source	23 p. : ill Pittsburgh, PA: Engineering Design Research Center CMU, December, 1986. EDRC-12-08-87. includes bibliography.
summary	An activity planning algorithm based on a network representations of conditions and actions is presented. The algorithm performs backward expansions on each desired condition in order to express them as a combination of initial conditions and actions. A global problem network of actions and conditions is used to represent the history of successful conditions expansions. This representation maintains consistency and improves the efficiency of search procedure. Interpretation of this problem network leads to an actions network from which feasible plans are directly obtained. The network algorithm was implemented in LISP and is applied here to solve blockworld problems similar to those found in the artificial intelligence planning literature. However, the algorithm and the network representation are general and intended to be used as an analytical tool in planning systems that formulate sequences of multiple actions
keywords	algorithms, planning, networks, representation, AI
series	CADline
last changed	2003/06/02 13:58

_id	a9b1
authors	Cohen, M.F., Greenberg, D.P. and Immel, D.S. (et al)
year	1986
title	An Efficient Radiosity Approach for Realistic Image Synthesis
source	IEEE Computer Graphics and Applications March, 1986. vol. 6: pp. 26-35 : col. ill. includes bibliography.
summary	The radiosity method models the interaction of light between diffusely reflecting surfaces and accurately predicts the global illumination effects. Procedures are now available to simulate complex environments including occluded and textured surfaces. For accurate rendering, the environment must be discretized into a fine mesh, particularly in areas of high intensity gradients. The interdependence between surfaces implies solution techniques which are computationally intractable. This article describes new procedures to predict the global illumination function without excessive computational expense. Statistics indicate the enormous potential of this approach for realistic image synthesis, particularly for dynamic images of static environments
keywords	computer graphics, radiosity, rendering, algorithms
series	CADline
last changed	2003/06/02 14:42

_id	e72a
authors	Putnam, L.K. and Subrahmanyam, P.A.
year	1986
title	Boolean Operations on n- Dimensional Objects
source	IEEE Computer Graphics and Applications. June, 1986. vol. 6: pp. 43-51 : ill. includes bibliography
summary	Computation of the union, intersection, and difference of n- dimensional objects plays a central role in several computer- aided geometric design problems. An algorithm for computing these operations that uses a boundary classification technique is presented here. The algorithm is recursive in structure, with the recursion being on the dimensions of objects dealt with at each stage. The representation treats all entities as objects, making no distinction between faces, edges or vertices. The objects produced are 'regularized,' that is, there are no degenerate boundaries such as dangling edges. The sample application given involved hidden-surface removal
keywords	algorithms, recursion, hidden surfaces, boolean operations, B-rep,geometric modeling
series	CADline
last changed	2003/06/02 13:58

_id	6733
authors	Bettels, Juergen and Myers, David R.
year	1986
title	The PIONS Graphics System
source	IEEE Computer Graphics and Applications. July, 1986. vol. 6: pp. 30-38 : col. ill. includes a short bibliography
summary	During 1979, CERN began to evaluate how interactive computer graphics displays could aid the analysis of high-energy physics experiments at the new Super Proton Synchrotron collider. This work led to PIONS, a 3D graphics system, which features the ability to store and view hierarchical graphics structures in a directed-acyclic-graph database. It is possible to change the attributes of these structures by making selections on nongraphical information also stored in the database. PIONS is implemented as an object-oriented message-passing system based on SmallTalk design principles. It supports multiple viewing transformations, logical input devices, and 2D and 3D primitives. The design allows full use to be made of display hardware that provides dynamic 3D picture transformation
keywords	visualization, computer graphics, database, systems, modeling
series	CADline
last changed	2003/06/02 13:58

_id	d37c
authors	Haines, Eric A. and Greenberg, Donald P.
year	1986
title	The Light Buffer: A Ray Tracer Shadow Testing Accelerator
source	Comput. Graph. and App., vol. 6, no. 9, pp. 6-16, IEEE, Sept. 1986
summary	The basic ideas presented are classifying objects from the light's viewpoint, and caching shadowing objects. The classification scheme uses a modified z-buffer to create lists of objects in sorted order for each "pixel" the light sees and determining depths beyond which no light passes. The other technique presented is caching the object that was last intersected by a shadow ray and immediately testing this object for the next shadow ray for the same light at the same location in the ray tree. Shadow caching is simple and applicable to almost any ray tracer. Dieter Bayer implemented the light buffer for POV-Ray.
series	other
email
last changed	2003/04/23 15:14

_id	2156
authors	Hashimshony, Rivka, Roth, J. and Wachman, A.
year	1986
title	A Model for Generating Floor-Plans in Multi-Story Buildings
source	International Journal of Design Computing. April, 1986. vol. 1: pp. 136-157 : ill. includes bibliography
summary	A graph-theoretic method for computer generation of rectangular floor plans for multi-story buildings is outlined. The problem formulation takes account of adjacency requirements of rooms, dimensional constraints, and the need for vertical alignments of elements such as stairs and elevators. The solution method is to first turn the required adjacencies graph into a layout graph by adding edges, then color and direct the layout graph, cut the colored directed graph into two subgraphs, and finally use the PERT technique to dimension the plan. An example problem of design of a medical clinic is formulated and solved using this method
keywords	space allocation, architecture, CAD, floor plans, synthesis, graphs, dimensioning
series	CADline
last changed	2003/06/02 10:24

_id	8816
authors	Penn, Michael A. and Patterson, Richard R.
year	1986
title	Projective Geometry and its Application to Computer Graphics
source	xi, 403 p. Englewood Cliffs, New Jersey: Prentice Hall, 1986. includes bibliography: p. 394-395
summary	The goal of the book is to support the design of solutions to computer graphic problems through an understanding of the underlying elements of projective geometry. Some of the topics discussed are: How to view the structure of two and three dimensional graphic libraries, how to create two dimensional perspective and parallel images of a three dimensional object, how to draw the graph of a function of two real variables, and more
keywords	computer graphics, projective geometry
series	CADline
last changed	2003/06/02 13:58

_id	4c79
authors	Aguilar, Lorenzo
year	1986
title	A Format for a Graphical Communications Protocol
source	IEEE Computer Graphics and Applications vol. 6.no. 3 (March, 1986): pp. 52-62
summary	This article describes the requirements for a graphical format on which a graphical on-line communications protocol can be based. It is argued that on-line graphical communications is similar to graphical session capture, and thus the author proposes an interactive graphical communications format using the GKSM session metafile. The discussion includes items that complement the GKSM metafile such as a format for on-line interactive exchange. One key application area of such a format is multimedia on-line conferencing. Therefore, a conferencing software architecture for processing the proposed format is presented. This format specification is made available to those planning multimedia conferencing systems
keywords	user interface, communication, computer graphics, multimedia, standards
series	CADline
last changed	1999/02/12 15:07

_id	678e
authors	Aish, Robert
year	1986
title	Three-dimensional Input and Visualization
source	Computer-Aided Architectural Design Futures [CAAD Futures Conference Proceedings / ISBN 0-408-05300-3] Delft (The Netherlands), 18-19 September 1985, pp. 68-84
summary	The aim of this chapter is to investigate techniques by which man-computer interaction could be improved, specifically in the context of architectural applications of CAD. In this application the object being designed is often an assembly of defined components. Even if the building is not actually fabricated from such components, it is usually conceptualized in these terms. In a conventional graphics- based CAD system these components are usually represented by graphical icons which are displayed on the graphics screen and arranged by the user. The system described here consists of three- dimensional modelling elements which the user physically assembles to form his design. Unlike conventional architectural models which are static (i.e. cannot be changed by the users) and passive (i.e. cannot be read by a CAD system), this model is both 'user generated' and 'machine readable'. The user can create, edit and view the model by simple, natural modelling activities and without the need to learn complex operating commands often associated with CAD systems. In particular, the user can view the model, altering his viewpoint and focus of attention in a completely natural way. Conventional computer graphics within an associated CAD system are used to represent the detailed geometry which the different three-dimensional icons may represent. In addition, computer graphics are also used to present the output of the performance attributes of the objects being modelled. In the architectural application described in this chapter an energy- balance evaluation is displayed for a building designed using the modelling device. While this system is not intended to offer a completely free-form input facility it can be considered to be a specialist man-machine interface of particular relevance to architects or engineers.
series	CAAD Futures
email
last changed	2003/11/21 15:15

_id	b25c
authors	Bergeson, Donald E. and Cetin, Randal F.
year	1986
title	ADAM - Architectural Design Applications Model
source	ACADIA Workshop ‘86 Proceedings - Houston (Texas - USA) 24-26 October 1986, pp. 37-54
doi	https://doi.org/10.52842/conf.acadia.1986.037
summary	This paper will describe ADAM, a project to explore the potential for interfacing independent graphics software for the purpose of developing a microcomputer based design system. This system will be implemented in three undergraduate design studios at the University of Illinois (Urbana-Champaign) School of Architecture. The three design studios are part of an experimental project to determine the usefulness of computers in the architectural design curriculum. The concept used throughout the design of this system is: "make use of what already exists, but use it smoothly together in such a way that the management system is totally invisible to the user." Many low- end quality graphics software packages are commercially available. Each has the capacity to address some aspect of the architectural design process, none will do it all . The problem is a lack of compatibility between software. ADAM is a management system designed to invisibly control and interface the use of an assembly of graphics programs and data base management systems to achieve compatibility. Because of these compatible interfaces, new and varied design tools can be created from existing software..
series	ACADIA
last changed	2022/06/07 07:54

_id	caadria2006_601
id	caadria2006_601
authors	BINSU CHIANG, MAO-LIN CHIU
year	2006
title	PRIVATE/UN-PRIVATE SPACE: Scenario-based Digital Design for Enhancing User Awareness
source	CAADRIA 2006 [Proceedings of the 11th International Conference on Computer Aided Architectural Design Research in Asia] Kumamoto (Japan) March 30th - April 2nd 2006, 601-603
doi	https://doi.org/10.52842/conf.caadria.2006.x.s8b
summary	Context awareness is important for human senses of places as well as human computer interaction. The aim of this research paper is focusing on controlling the user's privacy in a smart space which is adaptive to different users for enhancing the user's awareness in his diary life. In Environmental Psychology, the definition of privacy is that an individual has the control of deciding what information of himself is released to others, and under how he interact with others. (Westin 1970) And privacy is categorized as the linguistic privacy and visual privacy. (Sundstorm 1986). Solutions for privacy control: Plan Layout, Vision Boundary, Access Control and Architecture Metaphor - the transmission of information is not ascertainable for every single user. Although information are shown in public, but information is implied by cues and symbols. Only a certain user or a group of users have access to the full context of information. The methodology is to form an analytic framework to study the relationship between information, user and activities by using the computational supports derived from KitchenSense, ConceptNet, Python, 3d Studio Max and Flash; and to record patterns built up by users' behaviour and actions. Furthermore, the scenario-based simulation can envision the real world conditions by adding interfaces for enhancing user awareness.
series	CAADRIA
email
last changed	2022/06/07 07:49

_id	e43b
authors	Blasi, D. and Scudo, G.
year	1986
title	Experience of Output Visualisation in Thermal Performance Analysis and Design.
source	Teaching and Research Experience with CAAD [4th eCAADe Conference Proceedings] Rome (Italy) 11-13 September 1986, pp. 186-191
doi	https://doi.org/10.52842/conf.ecaade.1986.186
summary	GKS didactic application in output visualisation of thermal behaviour simulation in building analysis and design. Energy analysis is performed by BEETA (Built Environment Energy Test and Analysis) code. It is a numerical simulation code which allows to simulate the building multizone thermal behaviour with different passive devices (Direct Gain, Greenhouse, Solar Chimney, Trompe, Convective and Radiative Cooling etc.). The code is based on thermal network theory and methods; the set of thermal equation is normally solved every hour or less by the coefficient matrix inversion method. An interactive loop is provide for dealing with non- linear thermal conductance problems with continuous or step variation (i.e. air mixing through an opening between two spaces, Trompe wall convective loop, etc.) The code allows to take into account urban obstructions and shading devices.
series	eCAADe
last changed	2022/06/07 07:52

_id	c5af
authors	Bobrow, Daniel G. and Stefik, Mark J.
year	1986
title	Perspective on Artificial Intelligence Programming
source	Science. February, 1986. vol. 231: pp. 951-956
summary	Programming systems for artificial intelligence application use specialized languages, environments, and knowledge-based tools to reduce the complexity of the programming task. Language style based on procedure, objects logic rules, and constraints reflect different models for organizing programs and facilitate program evaluation and understandability. To make programming easier, multiple styles can be integrated as sublanguages in programming environment. Programming environments provide tools that analyze programs and create informative displays of their structure. Programs can be modified by direct interaction with these displays. These tools and languages are helping computer scientists to regain a sense of control over systems that have become increasingly complex
keywords	programming, AI
series	CADline
last changed	2003/06/02 13:58

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