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IBM Journal of Research and Development

Issue 3 • Date May 1987

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Displaying Results 1 - 13 of 13
  • Preface

    Publication Year: 1987 , Page(s): 276
    Click to expandAbstract | PDF file iconPDF (125 KB)  

    This issue is devoted to aspects of computer-aided design (CAD). The objectives of CAD are top rovide means for the design and analysis of products and their manufacturing environments to ensureh igh-quality, economical, error-free designs. created with high productivity and short lead times. These objectives are tied to the concept of using interactive systems to synthesize designs and, through e... View full abstract»

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  • Solid modeling for production design

    Publication Year: 1987 , Page(s): 277 - 295
    Cited by:  Papers (2)  |  Patents (4)
    Click to expandAbstract | PDF file iconPDF (1540 KB)  

    This paper describes a solid modeling and interactive graphics computer system which is being used for conceptual and detailed design by the mechanical design community at IBM's Data Systems Division Laboratory in Poughkeepsie, New York. The system has evolved from research on solid modeling begun at IBM's Thomas J. Watson Research Center in the mid-70s. Its development has resulted in one of the ... View full abstract»

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  • Piecewise-circular curves for geometric modeling

    Publication Year: 1987 , Page(s): 296 - 313
    Cited by:  Papers (3)  |  Patents (2)
    Click to expandAbstract | PDF file iconPDF (1416 KB)  

    Modern solid modelers must be able to represent a wide class of objects, and must support Boolean operations on solids. These operations are very useful for defining solids, detecting interferences, and modeling fabrication processes. Computing the boundaries of solids defined through Boolean operations requires algorithms for surface/surface and curve/surface intersection. Many of the currently a... View full abstract»

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  • Trimmed-surface algorithms for the evaluation and interrogation of solid boundary representations

    Publication Year: 1987 , Page(s): 314 - 334
    Cited by:  Papers (8)  |  Patents (1)
    Click to expandAbstract | PDF file iconPDF (1582 KB)  

    Although trimmed surfaces play a fundamental role in the derivation and processing of solid boundary representations, they have received little attention to date. We propose a trimmed-surface formulation appropriate to the Boolean combination of primitives bounded by a family of elementary surface patches (e.g., planes, quadrics, ruled surfaces, surfaces of revolution) with dual parametric rationa... View full abstract»

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  • Simple unit vectors orthogonal to a given vector

    Publication Year: 1987 , Page(s): 335 - 342
    Click to expandAbstract | PDF file iconPDF (581 KB)  

    In geometrical computations it is often necessary to find two unit vectors such that they and a given vector form an orthogonal basis. Computationally simple forms for the two unit vectors are clearly useful. We show that they cannot always be chosen to have rational coordinates, but that in general the simplest possible vectors can be chosen to involve only one square root. We develop number-theo... View full abstract»

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  • Shaping geometric objects by cumulative translational sweeps

    Publication Year: 1987 , Page(s): 343 - 360
    Cited by:  Papers (3)  |  Patents (5)
    Click to expandAbstract | PDF file iconPDF (1889 KB)  

    This paper introduces the cumulative translational sweep (CTS) as a tool for shaping geometric objects. It describes how it may be applied, in combination with Boolean operations, to stimulate growth and shrinking over the boundary regions of polyhedral models, and how, by creating additional facets, it may be used to achieve global rounding effects along model edges and around their vertices. CTS... View full abstract»

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  • Voronoi diagram for multiply-connected polygonal domains I: Algorithm

    Publication Year: 1987 , Page(s): 361 - 372
    Cited by:  Papers (9)  |  Patents (1)
    Click to expandAbstract | PDF file iconPDF (869 KB)  

    Voronoi diagrams of multiply-connected polygonal domains (polygons with holes) can be of use in computer-aided design. We describe a simple algorithm that computes such Voronoi diagrams in O(N(log2 N+H)) time, where N is the number of edges and H is the number of holes. View full abstract»

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  • Voronoi diagram for multiply-connected polygonal domains II: Implementation and application

    Publication Year: 1987 , Page(s): 373 - 381
    Cited by:  Papers (3)  |  Patents (2)
    Click to expandAbstract | PDF file iconPDF (701 KB)  

    Voronoi diagrams have many novel applications in computer-aided design. In this paper, an implementation of a Voronoi diagram algorithm described in a companion paper by Srinivasan and Nackman is presented. This Voronoi diagram is then used for an application in which equivalent resistance networks are derived from a boundary representation of a two-dimensional VLSI geometry. View full abstract»

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  • An algorithm for automatic identification of R-fields in bond graphs

    Publication Year: 1987 , Page(s): 382 - 390
    Click to expandAbstract | PDF file iconPDF (743 KB)  

    Bond graphs may be used to model the power flow in dynamic systems. They are especially attractive for modeling systems which function in coupled energy domains, for example, electromechanical systems. For such systems, bond graphs can be used to provide a natural subdivision into power/energy fields: storage, sources, transformers, and dissipation. In the case of nonlinear dissipative fields, imp... View full abstract»

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  • Parallel algorithms for chip placement by simulated annealing

    Publication Year: 1987 , Page(s): 391 - 402
    Cited by:  Papers (15)
    Click to expandAbstract | PDF file iconPDF (959 KB)  

    We explore modifications to the standard simulated annealing method for circuit placement which make it more suitable for use on a shared-memory parallel computer. By employing chaotic approaches we allow the parallel algorithms to deviate from the algorithm defined for a serial computer and thus obtain good execution efficiencies for large numbers of processors. The qualitative behavior of the pa... View full abstract»

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  • Recent publications by IBM authors

    Publication Year: 1987 , Page(s): 403 - 413
    Click to expandAbstract | PDF file iconPDF (933 KB)  

    The information listed here is supplied by the Institute for Scientific Information and other outside sources. Reprints of the papers may be obtained by writing directly to the firsat uthor cited. Information on books may be obtained by writing the publisher. Papers and books are listed alphabetically by author. View full abstract»

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  • Recent IBM patents

    Publication Year: 1987 , Page(s): 414 - 416
    PDF file iconPDF (179 KB)  
    Freely Available from IEEE
  • Errata [Erratum]

    Publication Year: 1987 , Page(s): 417
    PDF file iconPDF (75 KB)  
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Aims & Scope

The IBM Journal of Research and Development is a peer-reviewed technical journal, published bimonthly, which features the work of authors in the science, technology and engineering of information systems.

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Meet Our Editors

Editor-in-Chief
Clifford A. Pickover
IBM T. J. Watson Research Center