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

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Hits 1 to 20 of 2183

_id 8e02
authors Brown, A.G.P. and Coenen, F.P.
year 2000
title Spatial reasoning: improving computational efficiency
source Automation in Construction 9 (4) (2000) pp. 361-367
summary When spatial data is analysed the result is often very computer intensive: even by the standards of contemporary technologies, the machine power needed is great and the processing times significant. This is particularly so in 3-D and 4-D scenarios. What we describe here is a technique, which tackles this and associated problems. The technique is founded in the idea of quad-tesseral addressing; a technique, which was originally applied to the analysis of atomic structures. It is based on ideas concerning Hierarchical clustering developed in the 1960s and 1970s to improve data access time [G.M. Morton, A computer oriented geodetic database and a new technique on file sequencing, IBM Canada, 1996.], and on atomic isohedral (same shape) tiling strategies developed in the 1970s and 1980s concerned with group theory [B. Grunbaum, G.C. Shephard, Tilings and Patterns, Freeman, New York, 1987.]. The technique was first suggested as a suitable representation for GIS in the early 1980s when the two strands were brought together and a tesseral arithmetic applied [F.C. Holdroyd, The Geometry of Tiling Hierarchies, Ars Combanitoria 16B (1983) 211–244.; S.B.M. Bell, B.M. Diaz, F.C. Holroyd, M.J.J. Jackson, Spatially referenced methods of processing raster and vector data, Image and Vision Computing 1 (4) (1983) 211–220.; Diaz, S.B.M. Bell, Spatial Data Processing Using Tesseral Methods, Natural Environment Research Council, Swindon, 1986.]. Here, we describe how that technique can equally be applied to the analysis of environmental interaction with built forms. The way in which the technique deals with the problems described is first to linearise the three-dimensional (3-D) space being investigated. Then, the reasoning applied to that space is applied within the same environment as the definition of the problem data. We show, with an illustrative example, how the technique can be applied. The problem then remains of how to visualise the results of the analysis so undertaken. We show how this has been accomplished so that the 3-D space and the results are represented in a way which facilitates rapid interpretation of the analysis, which has been carried out.
series journal paper
more http://www.elsevier.com/locate/autcon
last changed 2003/05/15 21:22

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

_id sigradi2006_e028c
id sigradi2006_e028c
authors Griffith, Kenfield; Sass, Larry and Michaud, Dennis
year 2006
title A strategy for complex-curved building design:Design structure with Bi-lateral contouring as integrally connected ribs
source SIGraDi 2006 - [Proceedings of the 10th Iberoamerican Congress of Digital Graphics] Santiago de Chile - Chile 21-23 November 2006, pp. 465-469
summary Shapes in designs created by architects such as Gehry Partners (Shelden, 2002), Foster and Partners, and Kohn Peterson and Fox rely on computational processes for rationalizing complex geometry for building construction. Rationalization is the reduction of a complete geometric shape into discrete components. Unfortunately, for many architects the rationalization is limited reducing solid models to surfaces or data on spread sheets for contractors to follow. Rationalized models produced by the firms listed above do not offer strategies for construction or digital fabrication. For the physical production of CAD description an alternative to the rationalized description is needed. This paper examines the coupling of digital rationalization and digital fabrication with physical mockups (Rich, 1989). Our aim is to explore complex relationships found in early and mid stage design phases when digital fabrication is used to produce design outcomes. Results of our investigation will aid architects and engineers in addressing the complications found in the translation of design models embedded with precision to constructible geometries. We present an algorithmically based approach to design rationalization that supports physical production as well as surface production of desktop models. Our approach is an alternative to conventional rapid prototyping that builds objects by assembly of laterally sliced contours from a solid model. We explored an improved product description for rapid manufacture as bilateral contouring for structure and panelling for strength (Kolarevic, 2003). Infrastructure typically found within aerospace, automotive, and shipbuilding industries, bilateral contouring is an organized matrix of horizontal and vertical interlocking ribs evenly distributed along a surface. These structures are monocoque and semi-monocoque assemblies composed of structural ribs and skinning attached by rivets and adhesives. Alternative, bi-lateral contouring discussed is an interlocking matrix of plywood strips having integral joinery for assembly. Unlike traditional methods of building representations through malleable materials for creating tangible objects (Friedman, 2002), this approach constructs with the implication for building life-size solutions. Three algorithms are presented as examples of rationalized design production with physical results. The first algorithm [Figure 1] deconstructs an initial 2D curved form into ribbed slices to be assembled through integral connections constructed as part of the rib solution. The second algorithm [Figure 2] deconstructs curved forms of greater complexity. The algorithm walks along the surface extracting surface information along horizontal and vertical axes saving surface information resulting in a ribbed structure of slight double curvature. The final algorithm [Figure 3] is expressed as plug-in software for Rhino that deconstructs a design to components for assembly as rib structures. The plug-in also translates geometries to a flatten position for 2D fabrication. The software demonstrates the full scope of the research exploration. Studies published by Dodgson argued that innovation technology (IvT) (Dodgson, Gann, Salter, 2004) helped in solving projects like the Guggenheim in Bilbao, the leaning Tower of Pisa in Italy, and the Millennium Bridge in London. Similarly, the method discussed in this paper will aid in solving physical production problems with complex building forms. References Bentley, P.J. (Ed.). Evolutionary Design by Computers. Morgan Kaufman Publishers Inc. San Francisco, CA, 1-73 Celani, G, (2004) “From simple to complex: using AutoCAD to build generative design systems” in: L. Caldas and J. Duarte (org.) Implementations issues in generative design systems. First Intl. Conference on Design Computing and Cognition, July 2004 Dodgson M, Gann D.M., Salter A, (2004), “Impact of Innovation Technology on Engineering Problem Solving: Lessons from High Profile Public Projects,” Industrial Dynamics, Innovation and Development, 2004 Dristas, (2004) “Design Operators.” Thesis. Massachusetts Institute of Technology, Cambridge, MA, 2004 Friedman, M, (2002), Gehry Talks: Architecture + Practice, Universe Publishing, New York, NY, 2002 Kolarevic, B, (2003), Architecture in the Digital Age: Design and Manufacturing, Spon Press, London, UK, 2003 Opas J, Bochnick H, Tuomi J, (1994), “Manufacturability Analysis as a Part of CAD/CAM Integration”, Intelligent Systems in Design and Manufacturing, 261-292 Rudolph S, Alber R, (2002), “An Evolutionary Approach to the Inverse Problem in Rule-Based Design Representations”, Artificial Intelligence in Design ’02, 329-350 Rich M, (1989), Digital Mockup, American Institute of Aeronautics and Astronautics, Reston, VA, 1989 Schön, D., The Reflective Practitioner: How Professional Think in Action. Basic Books. 1983 Shelden, D, (2003), “Digital Surface Representation and the Constructability of Gehry’s Architecture.” Diss. Massachusetts Institute of Technology, Cambridge, MA, 2003 Smithers T, Conkie A, Doheny J, Logan B, Millington K, (1989), “Design as Intelligent Behaviour: An AI in Design Thesis Programme”, Artificial Intelligence in Design, 293-334 Smithers T, (2002), “Synthesis in Designing”, Artificial Intelligence in Design ’02, 3-24 Stiny, G, (1977), “Ice-ray: a note on the generation of Chinese lattice designs” Environmental and Planning B, volume 4, pp. 89-98
keywords Digital fabrication; bilateral contouring; integral connection; complex-curve
series SIGRADI
email
last changed 2016/03/10 09:52

_id ecaaderis2023_41
id ecaaderis2023_41
authors Hadighi, Mahyar and Hadighi, Mehrdad
year 2023
title Between System and Improvisation: Aesthetic performance in Donald Judd’s 100 untitled works in mill aluminum
source De Luca, F, Lykouras, I and Wurzer, G (eds.), Proceedings of the 9th eCAADe Regional International Symposium, TalTech, 15 - 16 June 2023, pp. 79–88
summary In this paper, we intend to analyze Donald Judd’s “100 untiled works in mill aluminum” to see whether they belong to a system, and, if so, what that system is and what delimits it. Our hypothesis is that there is a system driven by shape data, but the system is tempered by improvisational moments at multiple junctures in the project. We are interested in deciphering the systematic, but also the moments of artistic improvisation. To that end, we will look at the roots of data-driven design in the “serial” artworks of the early 1960’s documented in two Artforum essays by Bochner and Coplans, both citing Donald Judd. This period of artistic production is critical in the context of the development of shape grammars in computation which followed in the early 70’s with Stiny and Gips’s Shape Grammar essay. In 1983, Knight used shape grammar to describe the transformation of design languages. In the same period, Donald Judd, without the aid of computation or knowledge of shape grammar, developed a grammar towards the design of “100 untiled works in mill aluminum.” We intend to explore Judd’s 100 works as an example of the utilization of information and its analysis towards design and innovation, and to highlight the role of artistic improvisation in a systemic design process.
keywords Donald Judd, Design System, Shape Grammar, Serial Art.
series eCAADe
email
last changed 2024/02/05 14:28

_id 49a8
authors McCall, R., Fischer, G. and Morch, A.
year 1990
title Supporting Reflection-in-Action in the Janus Design Environment
source The Electronic Design Studio: Architectural Knowledge and Media in the Computer Era [CAAD Futures ‘89 Conference Proceedings / ISBN 0-262-13254-0] Cambridge (Massachusetts / USA), 1989, pp. 247-259
summary We have developed a computer-based design aid called Janus, which is based on a model of computer-supported design that we think has significance for the future of architectural education. Janus utilizes a knowledge-based approach to link a graphic construction system to hypertext. This allows the computer to make useful comments on the solutions that students construct in a CAD-like environment. These comments contain information intended to make students think more carefully about what they are doing while they are doing it. In other words, Janus promotes what Donald Schon has called "reflection-inaction" (Schon, 1983). The Janus design environment is named for the Roman god with a pair of faces looking in opposite directions. In our case the faces correspond to complementary design activities we call construction and argumentation. Construction is the activity of graphically creating the form of the solution e.g., a building. Traditionally this has been done with tracing paper, pencils, and pens. Argumentation is the activity of reasoning about the problem and its solution. This includes such things as considering what to do next, what alternative courses of action are available, and which course of action to choose. Argumentation is mostly verbal but partly graphical.
series CAAD Futures
last changed 1999/04/03 17:58

_id a04f
authors Smeltzer, G.T.A.
year 1983
title Integration of Design Methods, Industrial Engineering and Informatics
source Proceedings of the International Conference eCAADe [European Computer Aided Architectural Design Education] Brussels (Belgium) 1983, pp. I.20-I.28
doi https://doi.org/10.52842/conf.ecaade.1983.x.q8r
summary With the composition of a new CAD education plan the opportunity presents itself to enter into new, valuable relationships with other faculties or faculty-units, at present already working in specific fields as computing or designing. Certain aspects, which are important for CAD-Education, have already been taught for a longer period before CAD became a special, recognized part in the curriculum of the faculty. Because the university cannot afford duplication anymore, and because a unit concerned with CAD cannot have all the necessary knowhow of all specialities at its own disposal, it is an important task of that unit to integrate relevant parts or aspects of faculty or unit-curricula.
keywords CAD Education, Curriculum
series eCAADe
email
last changed 2022/06/07 07:50

_id ecaade2022_299
id ecaade2022_299
authors Bauscher, Erik, Philipp, Klaus Jan, Reisinger, Stefanie and Wortmann, Thomas
year 2022
title Reimagining Gego: Geometrical Reconstruction of Nubes, an Undocumented and Lost Sculpture from 1974
source Pak, B, Wurzer, G and Stouffs, R (eds.), Co-creating the Future: Inclusion in and through Design - Proceedings of the 40th Conference on Education and Research in Computer Aided Architectural Design in Europe (eCAADe 2022) - Volume 2, Ghent, 13-16 September 2022, pp. 217–226
doi https://doi.org/10.52842/conf.ecaade.2022.2.217
summary This paper describes a method to understand and digitally reconstruct two sculptures by Gertrud Goldschmidt, a German-born, Venezuelan artist also called Gego. Gego is best known for her series of works called “Reticuláres”. These three-dimensional and open installations, mostly hanging freely in space, are playing with the concept and perception of space as well as challenging the definition of the traditional sculpture. The paper aims to generate information about two specific structures called “Nubes” (Clouds for Spanish) to assist in a physical reconstruction for a larger exhibition about Gego and to contribute to understanding Gego’s work process. Originally, the structures were suspended from a building's ceiling as an art installation in Caracas, 1974. There are three main challenges for this reconstruction: (1) The installations exhibit a complex three-dimensional geometry. (2) Scant drawings and photographs exist. (3) Gego might not have followed her initial drawings completely when building Nubes physically, because of the mentioned complexity and due to the light and bendable material properties of the employed material. The paper describes a computational process that recreates the object’s geometry in four steps: (1) Analyse all existing media of the structure. (2) Translate found information to the digital environment of Grasshopper. (3) Use a physical simulation to derive the end state of the hanging structure. (4) Optimize and tune the simulation with an optimization algorithm for better results. This paper demonstrates the usefulness of computational tools for reconstructing lost sculptures with little documentation. In this case, these tools allow a more accurate reconstruction and contribute to a fuller understanding of the design and realization process of Gego's Nubes.
keywords Geometry Reconstruction, Lost Art, Computational Design, Physics Simulation
series eCAADe
email
last changed 2024/04/22 07:10

_id ddss9432
id ddss9432
authors Goldschmidt, G.
year 1994
title Visual Reference for Design: Analogy, Transformation and the Act of Sketching
source Second Design and Decision Support Systems in Architecture & Urban Planning (Vaals, the Netherlands), August 15-19, 1994
summary All designers know that it is impossible to infer a design solution from the givens of a task alone, no matter how complete and well presented they are. Therefore, designers seek to complementinformation they receive, and the material they bring into the task environment includes visual images. Images may be gathered from every imaginable source, from domain-specific images (in architecture they are usually classified and pertain to building type, location, period, technology, style or creator) through 'metaphoric' images (art, nature) to eclectic personal favourites. Inaddition, randomly encountered images may find their way into a database of references: a depository of potentially useful images. With the exception of factual information that fills in thetask givens, it is usually far from clear what purpose may be served by images in general, or to what use the specific images aligned for a particular task may be put. We propose that the singlemost significant 'on line' role of visual references during the process of designing is to suggest potential analogies to the entity that is being designed. The process of discovering and exploitingan analogy in design is complex; we shall explain it in terms of Gentner's structure mapping theory, which we adapt to visual structures. We further propose that the abstraction process thatmust take place for the successful identification and mapping from source (visual reference) onto target (designed entity) requires transformations of images, and such transformations are bestachieved through sketching. Sketching facilitates the two way process of movement from the pictorial to the diagrammatic and from the schematic to the figural. Such transformations musttake place to arrive at the match that allows conceptual transfer, mapping of structural relations and insight through analogy.
series DDSS
email
last changed 2003/08/07 16:36

_id f7b9
authors Goldschmidt, G.
year 1994
title On visual design thinking: the via kids of architecture
source Design Studies 15 (2), pp. 158-174
summary Designers invariably use imagery to generate new form combinations which they represent through sketching. But they also do the reverse: they sketch to generate images of forms in their minds. Common belief regards such activity as non-rational. In contrast, we assert that interactive imagery through sketching is a rational mode of reasoning, characterized by systematic exchanges between conceptual and figural arguments. Cognitive science, strongly dominated by a linguistic paradigm, has yet to recognize the paramount role of visual reasoning in many instances of problem solving; and in design tool-making, computational and otherwise, we must learn to optimize rather than bypass intuitive visuality.
series journal paper
last changed 2003/04/23 15:14

_id a875
authors Suwa, M., Gero, J.S. and Purcell, T.
year 1999
title How an Architect Created Design Requirements
source G. Goldschmidt and W. Porter (eds), Design Thinking Research Symposium: Design Representation, MIT, Cambridge, pp. II.101-124
summary There is an anecdotal view that designers, during a conceptual design process, not just synthesise solutions that satisfy initially given requirements, but also create by themselves novel design requirements that capture important aspects of the given problem. Further, it is believed that design sketches serve as a thinking tool for designers to do this. Then, what kinds of cognitive interaction with their own sketches enable designers to create novel requirements? The purpose of this paper is to answer this question. We examined the cognitive processes of a practising architect, using a protocol analysis technique. Our examinations focused on whether particular types of cognitive actions account for the creation of novel design requirements. We found that intensive occurrences of a certain type of perceptual actions, acts of establishing new relations or visual features on the sketches, are likely to co-occur with the creation of requirements. This suggests that this type of perceptual actions are the key constituent of acts of creating novel requirements, and therefore one of the important actions in sketching activities. This presents evidence of the view that designing is a situated act, as well as has an implication for design education.
keywords Design Requirements; Sketches; Design Cognition; Protocol Analysis
series journal paper
email
last changed 2003/03/31 08:37

_id bacd
authors Abadí Abbo, Isaac
year 1999
title APPLICATION OF SPATIAL DESIGN ABILITY IN A POSTGRADUATE COURSE
source Full-scale Modeling and the Simulation of Light [Proceedings of the 7th European Full-scale Modeling Association Conference / ISBN 3-85437-167-5] Florence (Italy) 18-20 February 1999, pp. 75-82
summary Spatial Design Ability (SDA) has been defined by the author (1983) as the capacity to anticipate the effects (psychological impressions) that architectural spaces or its components produce in observers or users. This concept, which requires the evaluation of spaces by the people that uses it, was proposed as a guideline to a Masters Degree Course in Architectural Design at the Universidad Autonoma de Aguascalientes in Mexico. The theory and the exercises required for the experience needed a model that could simulate spaces in terms of all the variables involved. Full-scale modeling as has been tested in previous research, offered the most effective mean to experiment with space. A simple, primitive model was designed and built: an articulated ceiling that allows variation in height and shape, and a series of wooden panels for the walls and structure. Several exercises were carried out, mainly to experience cause -effect relationships between space and the psychological impressions they produce. Students researched into spatial taxonomy, intentional sequences of space and spatial character. Results showed that students achieved the expected anticipation of space and that full-scale modeling, even with a simple model, proved to be an effective tool for this purpose. The low cost of the model and the short time it took to be built, opens an important possibility for Institutions involved in architectural studies, both as a research and as a learning tool.
keywords Spatial Design Ability, Architectural Space, User Evaluation, Learning, Model Simulation, Real Environments
series other
type normal paper
email
more http://info.tuwien.ac.at/efa
last changed 2004/05/04 11:27

_id ecaade2009_123
id ecaade2009_123
authors Achten, Henri; Beetz, Jakob
year 2009
title What Happened to Collaborative Design?
source Computation: The New Realm of Architectural Design [27th eCAADe Conference Proceedings / ISBN 978-0-9541183-8-9] Istanbul (Turkey) 16-19 September 2009, pp. 357-366
doi https://doi.org/10.52842/conf.ecaade.2009.357
wos WOS:000334282200043
summary In this paper we present the results of a comprehensive literature survey on the development of collaborative design. We reviewed 324 papers on collaborative design, taken from various sources (conferences, journals, and PhD-theses). We grouped the papers based on common themes, and in that way derived a classification of themes through the last 25 years (1983-2008). Each category is described, its development, and key publications are identified.
keywords Collaborative design
series eCAADe
email
last changed 2022/06/07 07:54

_id 2387
authors Akin, Omer, Baykan, Can D. and Rao, Radha D.
year 1983
title Searching in the UNIX Directory
source December, 1983. 19 p. : ill., tables. includes bibliography
summary The structure of the directory space and subjects search behaviors in the UNIX operating system environment are examined. Protocol analysis with two subjects and survey of the contents of the directory space of all users of E-VAX and X-VAX systems in the Architecture and Computer Science Systems at Carnegie Mellon University were conducted. Depth first search characterized both the organization of the directories and the behavior of the subjects. Single step as opposed to multiple step traversal of the directory tree was also prevalent in the subject`s behaviors. Recommendations for system friendliness, in term of reusability, orientation, robustness, and consistency are developed
keywords UNIX, user interface, protocol analysis
series CADline
email
last changed 2003/06/02 13:58

_id 8d59
authors Andersen, J.M.
year 1983
title CAD in Architectural Practice
source Mechanical Engineering. July, 1983. pp. 48-54 : ill. includes a short bibliography
summary A leading architecture/engineering firm has made use of in- house computer system since 1963. This paper discusses some special topics in using computers for the design of HVAC systems, and the process of implementing CAD in the HVAC engineering practice
keywords computer graphics, HVAC, applications, practice, architecture
series CADline
last changed 2003/06/02 13:58

_id 21d8
authors Balas, Egon and Toth, Paolo
year 1983
title Branch and Bound Methods for the Traveling Salesman Problem
source December, 1983, 65 p. : ill., tables. Includes bibliography
summary This paper reviews the state of the art in enumerative solution methods for the traveling salesman problem (TSP). The introduction (Section 1) discusses the main ingredients of branch and bound methods for the TSP. Sections 2,3 and 4 discuss classes of methods based on three different relaxation of the TSP: the assignment problem with the TSP cost function, the 1-tree problem with a Lagrangean objective function, and the assignment problem with a lagrangean objective function. Section 5 briefly reviews some other relaxations of the TSP, while section 6 discusses the performance of some state of the art computer codes. Besides material from the literature, the paper also includes the results and statistical analysis of some computational experiments designed for the purposes of this review
keywords relaxation, branch-and-bound, algorithms, applications
series CADline
last changed 2003/06/02 13:58

_id e118
authors Balas, Egon
year 1983
title Disjunctive Programming and a Hierarchy of Relaxations for Discrete Optimization Problems
source December, 1983. 38 p. : ill. includes bibliography
summary The author discuss a new conceptual framework for the convexification of discrete optimization problems, and a general technique for obtaining approximations to the convex hull of the feasible set. The concepts come from disjunctive programming and the key tool is a description of the convex hull of a union of polyhedra in terms of a higher dimensional polyhedron. Although this description was known for several years, only recently was it shown by Jeroslow and Lowe to yield improved representations of discrete optimization problems. The author expresses the feasible set of a discrete optimization problem as the intersection (conjunction) of unions of polyhedra, and define an operation that takes one such expression into another, equivalent one, with fewer conjuncts. He then introduces a class of relaxations based on replacing each conjunct (union of polyhedra) by its convex hull. The strength of the relaxations increases as the number of conjuncts decreases, and the class of relaxations forms a hierarchy that spans the spectrum between the common linear programming relaxation, and the convex hull of the feasible set itself. Instances where this approach presents advantages include critical path problems in disjunctive graphs, network synthesis problems, certain fixed charge network flow problems, etc. The approach on the first of these problems is illustrated, which is a model for machine sequencing
keywords polyhedra, computational geometry, optimization, programming, convex hull, graphs
series CADline
last changed 1999/02/12 15:07

_id 41af
authors Barnhill, Robert E.
year 1983
title A Survey of the Representation and Design of Surfaces
source IEEE Computer Graphics and Applications. October, 1983. vol. 3: pp. 9-16 : ill. includes bibliography
summary The approach of devising robust surface methods applicable to arbitrarily located data was taken by the CAGD Group at the University of Utah. Adopting two broad classes of methods suitable for solving the problems (i.e., problems for which simplifying geometric assumptions cannot be made): (1) surface interpolants defined over triangles or tetrahedra and (2) distance-weighted interpolants. Interactive computer graphics was used to display surfaces for adequate visualization. Although some figures were given, it must be kept in mind that some 3-D medium, or at least motion, is necessary to understand surfaces
keywords computational geometry, computer graphics, representation, curved surfaces, mathematics
series CADline
last changed 2003/06/02 10:24

_id 86cb
authors Bell, John
year 1983
title Designers Get the Picture
source New Scientist March, 1983. pp. 815-[822] : col. ill.
summary One firm that had installed a CAD system is the Somerset Shoemaker Clarks Ltd. It took four years to develop the software that was developed by CADCenter in Cambridge. The article describes the program and the process of shoemaking
keywords CAD, practice, engineering
series CADline
last changed 1999/02/12 15:07

_id 213d
authors Bernard, Yves and Dupagne, Albert
year 1983
title Volume: a computer Program for building Modelisation and Manipulation
source Proceedings of the International Conference eCAADe [European Computer Aided Architectural Design Education] Brussels (Belgium) 1983, pp. III.70-III.79
doi https://doi.org/10.52842/conf.ecaade.1983.x.n2m
summary We describe a computer program VOLUME for interactive 3D modelling of building which can be used in many problems (heat losses calculations, architectural evaluation, ...) where a geometric representation is required. The program is more than a tool to input a geometry: it is also a tool for design; manipulations are very easy and many design solutions can be tried. We then discuss about developments for improving the quality of that tool in the design process.
keywords Computer Aided Design, 3D Modelling, Computer-user Interface, Evaluations
series eCAADe
email
more http://www.ulg.ac.be/lema/
last changed 2022/06/07 07:50

_id 2e0a
authors Besant, C.B.
year 1983
title Computer-Aided Design and Manufacture. -- 2nd. ed
source 232 p. : ill. Chicester [West Sussex], New York: Halsted Press, 1983. includes bibliography and index -- (Ellis Horwood Series in Engineering Science)
summary An introduction to computing as an aid to design and manufacture. Provides description of hardware and software of CAD systems, discusses their use in engineering drafting
keywords drafting, hardware, software, CAD, CAM, practice
series CADline
last changed 2003/06/02 13:58

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