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	6f1b
authors	De Floriani, Leila and Falcidieno, Bianca
year	1988
title	A Hierarchical Boundary Model for Solid Object Representation
source	ACM Transactions on Graphics. January, 1988. vol. 7: pp. 42-60 : ill. includes bibliography
summary	A new hierarchical model for solid object representation is described. This model, called a Hierarchical Face Adjacency Hypergraph (HFAH), is based on a relational description of the object boundary, called a Face Adjacency Hypergraph (FAH), which considers faces as the primary topological entities defining the object boundary. The HFAH consists of a hierarchy of FAHs describing the decomposition of the boundary of an object into form features. In this paper the HFAH is described together with its internal encoding structure. Two basic transformations, called refinement and abstraction, are defined on the hierarchical model; these allow effective and efficient modifications of the hierarchical boundary model
keywords	representation, computational geometry, solid modeling, algorithms, design, data structures, graphs, features, B-rep
series	CADline
last changed	2003/06/02 13:58

_id	c6d5
authors	Balachandran, M.B.
year	1988
title	A Model for Knowledge-Based Design Optimization [PhD dissertation]
source	Dept. of Architectural Science, University of Sydney
summary	Unpublished. CADLINE has abstract only. This dissertation is concerned with developments in design decision methodologies applied to computer-aided design. The major aim of this research was to design and develop a knowledge-based computer-aided optimization system that has the ability to emulate some of the human performances in design decision processes. The issues and problems involved in developing a knowledge-based system for design optimization are addressed. A knowledge-based methodology to aid design optimization formulation is investigated. The major issues considered include representation of design description, the variety of knowledge required for the formulation process, recognizing optimization formulations, and selection of appropriate algorithms. It is demonstrated that the knowledge-based control of numerical processes leads to efficient and improved decisions in design. In developing knowledge-based systems for computer-aided decision applications an effective human-machine interface is essential. A model for knowledge-based graphical interfaces is proposed. This model incorporates knowledge for graphics interpretation, extraction of features of graphics objects and identification of prototypical objects. An experimental system developed in Prolog and C is demonstrated in the domain of structural design. The system shows one way of combining knowledge-based systems technology with computer graphics and indicates how knowledge-based interfaces improve the system's interactive capabilities. Finally, the system, OPTIMA, is presented. The system is designed as an integrated knowledge-based decision system using frames, rule bases, menu inputs, algebraic computation and optimization algorithms. The system has been written in LISP, Prolog and C and implemented on SUN Microsystems workstations. The performance of the system is demonstrated using two example problems from the domains of structural and architectural design respectively. The knowledge-based approach to design optimization is shown to be considerably easier and more efficient than those using conventional programs.
keywords	Knowledge Base, Systems, CAD, Representation, Design, Frames, Computer Graphics, User Interface, Decision Making
series	CADline
last changed	2003/06/02 13:58

_id	ea6a
authors	Bentley, Jon L.
year	1988
title	More Programming Pearls : Confessions of a Coder
source	207 p. : ill. Reading, Massachusetts: Addison-Wesley Publishing Co., 1988. includes index
summary	A collection of essays demonstrating the various aspects of programming. Some cover programming techniques using the C and AWK languages, other essays discuss making I/O fit for humans and several sub routines
keywords	programming, algorithms, techniques
series	CADline
last changed	2003/06/02 13:58

_id	0149
authors	Mackenzie, C.A.
year	1988
title	Heuristic Search and Tree Systems Inference for Structural Pattern Recognition
source	Knowledge based systems. 1988. vol. 1: pp. 78-89
summary	An experiment is reported that combines the use of a heuristic search and a tree systems inference technique to induce context-free relational grammars that generate patterns in the style embodied in a sample set. This is achieved by searching for concise structural representations of each pattern in a sample set and discovering regularities in their tree systems representation. The knowledge induced is represented as an accepting tree systems automation and generative grammar, and is used to classify extant patterns and generate novel ones. Examples are given to illustrate the methodology, and to lend support to the hypothesis that the style of a pattern can be partially characterized by a unique generative process
keywords	algorithms, heuristics, search, pattern recognition, inference, shape grammars
series	CADline
last changed	2003/06/02 13:58

_id	c7e9
authors	Maver, T.W.
year	2002
title	Predicting the Past, Remembering the Future
source	SIGraDi 2002 - [Proceedings of the 6th Iberoamerican Congress of Digital Graphics] Caracas (Venezuela) 27-29 november 2002, pp. 2-3
summary	Charlas Magistrales 2There never has been such an exciting moment in time in the extraordinary 30 year history of our subject area, as NOW,when the philosophical theoretical and practical issues of virtuality are taking centre stage.The PastThere have, of course, been other defining moments during these exciting 30 years:• the first algorithms for generating building layouts (circa 1965).• the first use of Computer graphics for building appraisal (circa 1966).• the first integrated package for building performance appraisal (circa 1972).• the first computer generated perspective drawings (circa 1973).• the first robust drafting systems (circa 1975).• the first dynamic energy models (circa 1982).• the first photorealistic colour imaging (circa 1986).• the first animations (circa 1988)• the first multimedia systems (circa 1995), and• the first convincing demonstrations of virtual reality (circa 1996).Whereas the CAAD community has been hugely inventive in the development of ICT applications to building design, it hasbeen woefully remiss in its attempts to evaluate the contribution of those developments to the quality of the built environmentor to the efficiency of the design process. In the absence of any real evidence, one can only conjecture regarding the realbenefits which fall, it is suggested, under the following headings:• Verisimilitude: The extraordinary quality of still and animated images of the formal qualities of the interiors and exteriorsof individual buildings and of whole neighborhoods must surely give great comfort to practitioners and their clients thatwhat is intended, formally, is what will be delivered, i.e. WYSIWYG - what you see is what you get.• Sustainability: The power of «first-principle» models of the dynamic energetic behaviour of buildings in response tochanging diurnal and seasonal conditions has the potential to save millions of dollars and dramatically to reduce thedamaging environmental pollution created by badly designed and managed buildings.• Productivity: CAD is now a multi-billion dollar business which offers design decision support systems which operate,effectively, across continents, time-zones, professions and companies.• Communication: Multi-media technology - cheap to deliver but high in value - is changing the way in which we canexplain and understand the past and, envisage and anticipate the future; virtual past and virtual future!MacromyopiaThe late John Lansdown offered the view, in his wonderfully prophetic way, that ...”the future will be just like the past, onlymore so...”So what can we expect the extraordinary trajectory of our subject area to be?To have any chance of being accurate we have to have an understanding of the phenomenon of macromyopia: thephenomenon exhibitted by society of greatly exaggerating the immediate short-term impact of new technologies (particularlythe information technologies) but, more importantly, seriously underestimating their sustained long-term impacts - socially,economically and intellectually . Examples of flawed predictions regarding the the future application of information technologiesinclude:• The British Government in 1880 declined to support the idea of a national telephonic system, backed by the argumentthat there were sufficient small boys in the countryside to run with messages.• Alexander Bell was modest enough to say that: «I am not boasting or exaggerating but I believe, one day, there will bea telephone in every American city».• Tom Watson, in 1943 said: «I think there is a world market for about 5 computers».• In 1977, Ken Olssop of Digital said: «There is no reason for any individuals to have a computer in their home».The FutureJust as the ascent of woman/man-kind can be attributed to her/his capacity to discover amplifiers of the modest humancapability, so we shall discover how best to exploit our most important amplifier - that of the intellect. The more we know themore we can figure; the more we can figure the more we understand; the more we understand the more we can appraise;the more we can appraise the more we can decide; the more we can decide the more we can act; the more we can act themore we can shape; and the more we can shape, the better the chance that we can leave for future generations a trulysustainable built environment which is fit-for-purpose, cost-beneficial, environmentally friendly and culturally significactCentral to this aspiration will be our understanding of the relationship between real and virtual worlds and how to moveeffortlessly between them. We need to be able to design, from within the virtual world, environments which may be real ormay remain virtual or, perhaps, be part real and part virtual.What is certain is that the next 30 years will be every bit as exciting and challenging as the first 30 years.
series	SIGRADI
email
last changed	2016/03/10 09:55

_id	20aa
authors	Pekny, J. F. and Miller, D.L.
year	1988
title	Results from a Parallel Branch and Bound Algorithm for the Asymmetric Traveling Salesman Problem
source	[1], 8, [6] p. : tables Pittsburgh, PA: Engineering Design Research Center, CMU, 1988. EDRC-06-42-88. includes bibliography
summary	Computational results are presented for a parallel branch- and-bound algorithm that optimally solves the asymmetric traveling salesman problem. Results are presented for randomly generated problems with sizes ranging from 250 to 3000 cities
keywords	search, parallel processing, algorithms, branch-and-bound
series	CADline
last changed	2003/06/02 13:58

_id	861a
authors	Sedas, Sergio W. and Talukdar, Sarosh N.
year	1987
title	A Disassembly Planner for Redesign
source	The Winter Annual Meeting of the American Society of Mechanical Engineers. Symposium of Intelligent and Integrated Manufacturing Analysis and Synthesis. December, 1987. Pittsburgh, PA: Engineering Design Research Center, CMU, 1988. [6] p. : ill. includes bibliography
summary	This paper describes an algorithm for generating plans for disassembling given objects. The plans are produced by a set of knowledge sources acting on a set of representations for the object. Both sets are arbitrarily expandable, so programs using the approach can grow continually in capability. Our present complement of knowledge sources and representations can tackle relatively difficult problems. Three examples are included. The first requires a good bit of geometric reasoning before appropriate subassemblies can be selected. The second and third require certain movable parts to be repositioned before disassembly can be achieved
keywords	algorithms, representation, synthesis, assemblies, knowledge, reasoning, mechanical engineering
series	CADline
last changed	2003/06/02 13:58

_id	7812
authors	Straber, W. and Seidel, H.-P. (eds.)
year	1989
title	Theory and Practice of Geometric Modeling
source	Springer-Verlag
summary	This book originates from the lectures given at the international conference "Theory and Practice of Geometric Modeling", Blaubeuren, FRG, October 3-7, 1988, that brought together leading experts from universities, system developers, and system users, to discuss new concepts and future trends in geometric modeling. The book covers a variety of topics on an advanced level and is organized as follows. Part A contains new algorithms and techniques for modeling objects that are bounded by free form surfaces. Part B focuses on surface/surface intersections, new types of blending surfaces and speed ups for ray tracing. Part C contains some new geometric tools. Part D discusses different representation schemes in solid modeling, conversions between these different schemes, and some applications. Part E covers some issues of product modeling, automatic tolerancing, high level specification of solid models (constraints, features) and the need for better user interfaces.
series	other
last changed	2003/04/23 15:14

_id	abaf
authors	Veenstra, Jack and Ahuja, Narendra
year	1988
title	Line Drawings of Octree- Represented Objects
source	ACM Transactions on Graphicsò January, 1988. vol. 7: pp. 61-75 : ill. includes bibliography.
summary	The octree structure represents the space occupied by an object as a juxtaposition of cubes. The octree structure is highly sensitive to object location and orientation, and the three-dimensional shape of the represented object is obscured. It is helpful to be able to see the actual object represented by an octree, especially for visual performance evaluation of octree algorithms. This paper presents a display algorithm that helps visualize the three-dimensional space represented by the octree. Given an octree, the algorithm produces a line drawing of the object represented by the octree, using parallel projection, from any specified viewpoint with hidden lines removed. Example of some line drawing produced by the algorithm are given. The complexity of the algorithm is also discussed
keywords	hidden lines, drawings, solid modeling, representation, octree, display, computer graphics
series	CADline
last changed	2003/06/02 13:58

_id	0220
authors	Woodwark, J.R.
year	1988
title	Eliminating Redundant Primitives from Set- Theoretic Solid Models by a Consideration of Constituents
source	16 p. : ill. Winchester: IBM UK Scientific Center, IBM United Kingdom Laboratories Limited, April, 1988. IBM UKSC Report 188. includes bibliography
summary	Set-theoretic solid models often contain redundant primitives, which slow down rendering and other processes. They are not simple to remove, especially as there can be alternative eliminations that may not be equally desirable. There has been recent progress towards solving this problem, but existing techniques for eliminating such redundant primitives do not fully consider the possibilities and rely on repeated evaluation of parts of the object's boundary, a process that is likely to be very slow. This article proposes a technique that allows alternative eliminations to be examined, and outlines a potentially efficient, but geometrically approximate, method of implementation
keywords	solid modeling, CSG, primitives, algorithms
series	CADline
last changed	2003/06/02 13:58

_id	eb5f
authors	Al-Sallal, Khaled A. and Degelman, Larry 0.
year	1994
title	A Hypermedia Model for Supporting Energy Design in Buildings
source	Reconnecting [ACADIA Conference Proceedings / ISBN 1-880250-03-9] Washington University (Saint Louis / USA) 1994, pp. 39-49
doi	https://doi.org/10.52842/conf.acadia.1994.039
summary	Several studies have discussed the limitations of the available CAAD tools and have proposed solutions [Brown and Novitski 1987, Brown 1990, Degelman and Kim 1988, Schuman et al 1988]. The lack of integration between the different tasks that these programs address and the design process is a major problem. Schuman et al [1988] argued that in architectural design many issues must be considered simultaneously before the synthesis of a final product can take place. Studies by Brown and Novitski [1987] and Brown [1990] discussed the difficulties involved with integrating technical considerations in the creative architectural process. One aspect of the problem is the neglect of technical factors during the initial phase of the design that, as the authors argued, results from changing the work environment and the laborious nature of the design process. Many of the current programs require the user to input a great deal of numerical values that are needed for the energy analysis. Although there are some programs that attempt to assist the user by setting default values, these programs distract the user with their extensive arrays of data. The appropriate design tool is the one that helps the user to easily view the principal components of the building design and specify their behaviors and interactions. Data abstraction and information parsimony are the key concepts in developing a successful design tool. Three different approaches for developing an appropriate CAAD tool were found in the literature. Although there are several similarities among them, each is unique in solving certain aspects of the problem. Brown and Novitski [1987] emphasize the learning factor of the tool as well as its highly graphical user interface. Degelman and Kim [1988] emphasize knowledge acquisition and the provision of simulation modules. The Windows and Daylighting Group of Lawrence Berkeley Laboratory (LBL) emphasizes the dynamic structuring of information, the intelligent linking of data, the integrity of the different issues of design and the design process, and the extensive use of images [Schuman et al 19881, these attributes incidentally define the word hypermedia. The LBL model, which uses hypermedia, seems to be the more promising direction for this type of research. However, there is still a need to establish a new model that integrates all aspects of the problem. The areas in which the present research departs from the LBL model can be listed as follows: it acknowledges the necessity of regarding the user as the center of the CAAD tool design, it develops a model that is based on one of the high level theories of human-computer interaction, and it develops a prototype tool that conforms to the model.
series	ACADIA
email
last changed	2022/06/07 07:54

_id	696c
authors	Beheshti, M. and Monroy, M.
year	1988
title	Requirements for Developing an Information System for Architecture
source	CAAD futures ‘87 [Conference Proceedings / ISBN 0-444-42916-6] Eindhoven (The Netherlands), 20-22 May 1987, pp. 149-170
summary	This paper discusses possibilities of developing new tools for architectural design. It argues that architects should meet the challenge of information technology and computer-based design techniques. One such attempt has been the first phase of the development of an architectural design information system (ADIS), also an architectural design decision support system. The system should benefit from the developments of the artificial intelligence to enable the architect to have access to information required to carry out design work. In other words: the system functions as a huge on-line electronic library of architecture, containing up-to-date architectural design information, literature, documents, etc. At the same time, the system offers necessary design aids such as computer programs for design process, drawing programs, evaluation programs, cost calculation programs, etc. The system also provides data communication between the architect and members of the design coalition team. This is found to be of vital importance in the architectural design process, because it can enable the architect to fit in changes, brought about in the project by different parties. Furthermore, they will be able, to oversee promptly the consequences of changes or decisions in a comprehensive manner. The system will offer advantages over the more commonly applied microcomputer based CAAD and IGDM (integrated graphics database management) systems, or even larger systems available to an architect. Computer programs as well as hardware change rapidly and become obsolete. Therefore, unrelenting investment pressure to up-date both software and hardware exists. The financial burden of this is heavy, in particular for smaller architectural practices (for instance an architect working for himself or herself and usually with few or no permanent staff). ADIS, as an on-line architectural design aid, is constantly up-dated by its own organisation. This task will be co-ordinated by the ADIS data- base administrator (DBA). The processing possibilities of the system are faster, therefore more complex processing tasks can be handled. Complicated large graphic data files, can be easily retrieved and manipulated by ADIS, a large system. In addition, the cost of an on-line system will be much less than any other system. The system is based on one model of the architectural design process, but will eventually contain a variety of design models, as it develops. The development of the system will be an evolutionary process, making use of its users' feed-back system. ADIS is seen as a step towards full automation of architectural design practices. Apart from being an architectural design support system, ADIS will assist the architect in his/her administrative and organisational activities.
series	CAAD Futures
last changed	2003/11/21 15:16

_id	8ac0
authors	Birmingham, William P., Gupta, Anurag P. and Siewiorek, Daniel P.
year	1988
title	The MICON System for Computer Design
source	11 p. : ill. Pittsburgh, PA: Engineering Design Research Center, CMU, November, 1988. EDRC 18-10-89. includes bibliography
summary	The MICON system is an integrated collection of programs which automatically synthesizes small computer systems from high level specifications. The system address multiple levels of design, from logical through physical, providing a rapid prototyping capability. Two programs form MICON's nucleus: a knowledge-based synthesis tool called M1; and, an automated knowledge acquisition tool named CGEN which is used to teach M1 how to design. Other tools in the MICON system are an integrated database and associated data management tools. The system is fully functional, having been used to generate working designs. This paper describes the architecture and operation of the MICON system
keywords	integrated circuits, electrical engineering, design, systems, automation, integration
series	CADline
last changed	2003/06/02 13:58

_id	8c6d
authors	Brooks, H. Gordon
year	1988
title	A New Communication Model for Architecture Using Video and 3D Computer Animated Graphics
source	Computing in Design Education [ACADIA Conference Proceedings] Ann Arbor (Michigan / USA) 28-30 October 1988, pp. 263-274
doi	https://doi.org/10.52842/conf.acadia.1988.263
summary	The University of Arkansas School of Architecture has produced a half-hour television program describing Richard Meier's Atheneum in New Harmony, Indiana. The program uses an analysis technique developed by Dr. Geoffrey Baker, RIBA. The treatment for the material is a combination of on- site video and computer generated 3D animated graphics. An instrument was developed to evaluate the video and its 3D graphics. Based on analysis of the test data several conclusions are apparent. Students believe the video to be very helpful in understanding this building. This video appears to be paced too quickly for understanding in one viewing. Repetitive viewings of the video are helpful in understanding the content. Some students are able to understand principles presented visually better than those presented verbally, but best learning happens when information is reinforced visually and verbally.
series	ACADIA
last changed	2022/06/07 07:54

_id	e1e2
authors	Danahy, John
year	1988
title	Engaging Intuitive Visual Thinking in Urban Design Modelling: A Real-Time Hypothesis
source	Computing in Design Education [ACADIA Conference Proceedings] Ann Arbor (Michigan / USA) 28-30 October 1988, pp. 87-97
doi	https://doi.org/10.52842/conf.acadia.1988.087
summary	This paper will present prototypical software being used in the teaching of urban design to students and for use by professionals in the early stages of a project. The system is intended to support a heuristic approach to design. That is, it supports a process of refining ideas and understandings through a process of trial and error. The support or aid to design comes in the form of a didactic real-time programme. Its power lies in its ability to provide instantaneous response to operations on the data that can allow one to develop threedimensional spatial ideas in an intuitively driven manner. This condition appears to occur for both novice and expert computer operators. The presentation will present our experience to-date in using conventional computer graphic tools to represent design ideas and contrast it with a video demonstration of our prototypical dynamic urban design modelling software for the Silicon Graphics IRIS computers.
series	ACADIA
email
last changed	2022/06/07 07:55

_id	8385
authors	Holtz, Neal M. and Rasdorf, William J.
year	1988
title	An Evaluation of Programming Languages and Language Features for Engineering Software Development
source	International Journal of Engineering with Computers. Springer-Verlag, 1988. vol. 3: pp. 183-199
summary	Also published as 'Procedural Programming Languages for the Development of CAD and CAE Systems Software,' in the proceedings of ASME International Conference on Computers in Engineering (1987 : New York, NY). The scope of engineering software has increased dramatically in the past decade. In its early years, most engineering applications were concerned solely with solving difficult numerical problems, and little attention was paid to man- machine interaction, to data management, or to integrated software systems. Now computers solve a much wider variety of problems, including those in which numerical computations are less predominant. In addition, completely new areas of engineering applications such as artificial intelligence have recently emerged. It is well recognized that the particular programming language used to develop an engineering application can dramatically affect the development cost, operating cost. reliability, and usability of the resulting software. With the increase in the variety, functionality, and complexity of engineering software, with its more widespread use, and with its increasing importance, more attention must be paid to programming language suitability so that rational decisions regarding language selection may be made. It is important that professional engineers be aware of the issues addressed in this paper, for it is they who must design, acquire, and use applications software, as well as occasionally develop or manage its development. This paper addresses the need for engineers to possess a working knowledge of the fundamentals of computer programming languages. In pursuit of this, the paper briefly reviews the history of four well known programming languages. It then attempts to identify and to look critically at the attributes of programming languages that significantly affect the production of engineering software. The four procedural programming languages chosen for review are those intended for scientific and general purpose programming, FORTRAN 77, C, Pascal, and Modula-2. These languages are compared and some general observations are made. As it is felt important that professional engineers should be able to make informed decisions about programming language selection, the emphasis throughout this paper is on a methodology of evaluation of programming languages. Choosing an appropriate language can be a complex task and many factors must be considered. Consequently, fundamentals are stressed
keywords	programming, engineering, languages, software, management, evaluation, FORTRAN, C, PASCAL, MODULA-2, CAD, CAE
series	CADline
last changed	2003/06/02 13:58

_id	diss_howe
id	diss_howe
authors	Howe, Alan Scott
year	1988
title	A new paradigm for life-cycle management of kit-of-parts building systems
source	UNIVERSITY OF MICHIGAN , PhD
summary	The research described in this dissertation brings together various technologies in manufacturing and information management and suggests a new paradigm for the design, manufacture, and lifetime use of artifacts using kit-of-parts systems and rule-based assembly. The questions are asked: If architects, designers, and users were given direct online connection to real-time design information sources and fabrication processes, and have the ability to monitor and control the current state of designed objects throughout the objects' lifetime, how would the entire life-cycle of a product be affected, and how would design processes change? During the course of the research described in this dissertation, a series of simulations and experiments were conducted which produced a computer-based simulated design, manufacture, and use environment wherein these questions could begin to be answered. A kit-of-parts model building system was devised which could be used to design model buildings in virtual form by downloading virtual representations of the components from the Internet and assembling them into a desired form. The virtual model building could then be used to order the manufacture of real components online, and remotely controlled robots used to assemble the actual building on the site. Through the use of special hardware manufactured into the components, real-time remote monitoring and control of the current state of the finished model building was affected during the building's lifetime. The research establishes the feasibility of an online life-cycle environment where a virtual representation of an artifact is created and used to both manufacture a real-world counterpart and also monitor and control the current state of the real-world object. The state-of-the-art of pertinent technologies were explored through literature searches and experiments. Data representation, rule-based design techniques, robotics, and digital control were studied, and a series of design principles established which lend themselves toward a life-cycle management paradigm. Several case studies are cited which show how the design principles and life-cycle management environment can be applied to real buildings and other artifacts such as vehicles and marine structures. Ideas for expanded research on the life-cycle management paradigm are cited.
series	thesis:PhD
email
more	http://wwwlib.umi.com/dissertations/fullcit/9909905
last changed	2003/11/20 19:57

_id	0803
authors	Jabri, Marwan A. and Skellern, David J.
year	1988
title	Automatic Floorplan Design Using PIAF
source	August, 1988. 36 p. : ill. tables
summary	This paper presents PIAF (a Package for Intelligent and Algorithmic Floorplanning), developed at Sydney University Electrical Engineering (SUEE) for use in custom integrated circuit design. Floorplanning plays a crucial role in the design of custom integrated circuits. When design is approached in a top-down fashion, the function to be implemented on silicon is first decomposed in a conceptual phase into a Functional Block Diagram (FBD). This FBD has a 'blocks and buses' structure where blocks represent sub- functions and buses represent the interconnections that carry data and other information between blocks. The decomposition of the function into sub-functions is hierarchical and aims at reducing the complexity of the design problem. When the FBD is known, the floorplanning process may be performed. When this task is performed manually, the designer searches for a relative placement of the blocks and for an area and shape for each block to minimize the overall chip layout area while at the same time meeting design constraints such as design tool limitations, interconnection characteristics and technological design rules. PIAF is a knowledge-based system (KBS) that has been developed at SUEE during the last four years. It relies on a strategy that partitions the floorplanning task in a way that allows efficient use of heuristics and specialized design knowledge in the generation and pruning of the solution space. This paper presents the operation of PIAF and discusses several implementation issues including; KBS structure, knowledge representation, knowledge acquisition, current context memory design, design quality factors and explanation facility. This paper uses a running example to present the operation of each PIAF's KBS-based solving phases
keywords	knowledge, representation, knowledge acquisition, electrical engineering, design, integrated circuits, knowledge base, systems, layout, synthesis
series	CADline
last changed	2003/06/02 10:24

_id	0711
authors	Kunnath, S.K., Reinhorn, A.M. and Abel, J.F.
year	1990
title	A Computational Tool for Evaluation of Seismic Performance of RC Buildings
source	February, 1990. [1] 15 p. : ill. graphs, tables. includes bibliography: p. 10-11
summary	Recent events have demonstrated the damaging power of earthquakes on structural assemblages resulting in immense loss of life and property (Mexico City, 1985; Armenia, 1988; San Francisco, 1989). While the present state-of-the-art in inelastic seismic response analysis of structures is capable of estimating response quantities in terms of deformations, stresses, etc., it has not established a physical qualification of these end-results into measures of damage sustained by the structure wherein system vulnerability is ascertained in terms of serviceability, repairability, and/or collapse. An enhanced computational tool is presented in this paper for evaluation of reinforced concrete structures (such as buildings and bridges) subjected to seismic loading. The program performs a series of tasks to enable a complete evaluation of the structural system: (a) elastic collapse- mode analysis to determine the base shear capacity of the system; (b) step-by-step time history analysis using a macromodel approach in which the inelastic behavior of RC structural components is incorporated; (c) reduction of the response quantities to damage indices so that a physical interpretation of the response is possible. The program is built around two graphical interfaces: one for preprocessing of structural and loading data; and the other for visualization of structural damage following the seismic analysis. This program can serve as an invaluable tool in estimating the seismic performance of existing RC buildings and for designing new structures within acceptable levels of damage
keywords	seismic, structures, applications, evaluation, civil engineering, CAD
series	CADline
last changed	2003/06/02 14:41

_id	8403
authors	Mitchell, William J., Liggett, Robin S. and Tan, Milton
year	1988
title	The Topdown System and its use in Teaching - An Exploration of Structured, Knowledge-Based Design
source	Computing in Design Education [ACADIA Conference Proceedings] Ann Arbor (Michigan / USA) 28-30 October 1988, pp. 251-262
doi	https://doi.org/10.52842/conf.acadia.1988.251
summary	The Topdown System is a shell for use in developing simple (but we believe non-trivial) knowledge-based CAD systems. It provides a data structure, graphics capabilities, a sophisticated user interface, and programming tools for rapid construction of knowledge bases. Implementation is for Macintosh, Macintosh II, IBM PC/AT, PS12, and Sun workstations. The basic idea is that of top-down design - beginning with a very abstract representation, and elaborating that, in step-by-step fashion, into a complete and detailed representation. The basic operations are real-time parametric variation of designs (using the mouse and slide bar) and substitution of objects. Essentially, then, a knowledge-base in Topdown implements a kind of parametric shape grammar. The main applications of Topdown are in introductory teaching of CAD, and (since it provides a very quick and easy way for a user to develop detailed geometric models) to provide a uniform front-end for a variety of different applications. The shell, and some example knowledge-bases, are publicly available. This paper discusses the principles of the Topdown Shell, the implementation of knowledge bases within it, and a variety of practical design applications.
series	ACADIA
email
last changed	2022/06/07 07:58

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