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IBM Journal of Research and Development

Issue 6 • Date Nov. 1989

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Displaying Results 1 - 9 of 9
  • Coding for constrained channels: A comparison of two approaches

    Publication Year: 1989, Page(s):602 - 608
    Cited by:  Papers (7)  |  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (931 KB)

    We discuss the relation between some early techniques for constrained channel coding and more recent ones adapted from the mathematical area of symbolic dynamics. A primary difference between the two is that the latter focus on issues of code existence, whereas the former were primarily concerned with code construction and optimality. View full abstract»

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  • Matrix print actuator for dot band printer

    Publication Year: 1989, Page(s):609 - 617
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1269 KB)

    The design selection of an impact matrix print actuator is described, along with its method of design and optimization. The dot band printer concept is discussed in conjunction with operational requirements for the hammer; these requirements, and methods of meeting them, are presented. View full abstract»

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  • Preserving the integrity of cyclic-redundancy checks when protected text is intentionally altered

    Publication Year: 1989, Page(s):618 - 626
    Cited by:  Papers (2)  |  Patents (14)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1052 KB)

    As a digitally encoded message traverses a series of point-to-point communication links, it may be necessary to change the contents of that message at an intermediate station. If bit errors are introduced by the intermediary while the text is unprotected, these errors will be subsequently undetectable by cyclic redundancy checks. An algorithm is presented here for ensuring that such errors will no... View full abstract»

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  • Representing knowledge with functions and Boolean arrays

    Publication Year: 1989, Page(s):627 - 646
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1766 KB)

    Over the past eighteen years a variety of advanced decision support systems have been built with knowledge-based expert system (KBES) components. For the past eight years, a knowledge representation and manipulation (KRM) scheme called FABA (Functions And Boolean Arrays) has been used. It has two basic principles. First, knowledge is viewed as a functional mapping between input and output variable... View full abstract»

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  • Fault-simulation programs for integrated-circuit yield estimations

    Publication Year: 1989, Page(s):647 - 652
    Cited by:  Papers (5)  |  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (934 KB)

    Three programs are described here which have been used for integrated-circuit yield modeling at the IBM facility in Essex Junction, Vermont. The first program generates negative binomial distributions which are used to represent the frequency distribution of the number of faults per chip. Calculations with the generalized combination function A ! B in APL are limited to simulations of up to 99,999... View full abstract»

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  • Recent publications by IBM authors

    Publication Year: 1989, Page(s):653 - 663
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1123 KB)

    The informationl isted 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 first author 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: 1989, Page(s):664 - 666
    IEEE is not the copyright holder of this material | PDF file iconPDF (209 KB)
    Freely Available from IEEE
  • Author index for papers in Volume 33

    Publication Year: 1989, Page(s):667 - 670
    IEEE is not the copyright holder of this material | PDF file iconPDF (247 KB)
    Freely Available from IEEE
  • Subject index for papers in Volume 33

    Publication Year: 1989, Page(s):671 - 674
    IEEE is not the copyright holder of this material | PDF file iconPDF (340 KB)
    Freely Available from IEEE

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