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IBM Journal of Research and Development

Issue 6 • Date Nov. 1985

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Displaying Results 1 - 9 of 9
  • Adaptive cross-parity (AXP) code for a high-density magnetic tape subsystem

    Publication Year: 1985 , Page(s): 546 - 562
    Cited by:  Papers (12)  |  Patents (27)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (1463 KB)  

    This paper describes an error-correction system, called adaptive cross-parity (AXP) code, for the IBM 3480, a new high-density 18-track tape storage subsystem. Redundancy is applied to two interleaved sets of nine tracks in the same proportion as that in the previous IBM 3420 tape machines. The coding structure, however, is simpler, for it avoids the complex computations of Galois fields. The codi... View full abstract»

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  • Write equalization in high-linear-density magnetic recording

    Publication Year: 1985 , Page(s): 563 - 568
    Cited by:  Papers (37)  |  Patents (8)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (543 KB)  

    For many years, equalization has been used on the read side of a magnetic-recording channel to obtain a desired signal shape at the detector. Compensation on the write side has, for the most part, been limited to moving transition locations to offset read-signal peak shifts. This paper presents a new method of equalization on the write side through the addition of pulses at strategic locations on ... View full abstract»

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  • Image processing by simulated annealing

    Publication Year: 1985 , Page(s): 569 - 579
    Cited by:  Papers (27)  |  Patents (6)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (1015 KB)  

    It is shown that simulated annealing, a statistical mechanics method recently proposed as a tool in solving complex optimization problems, can be used in problems arising in image processing. The problems examined are the estimation of the parameters necessary to describe a geometrical pattern corrupted by noise, the smoothing of bi-level images, and the process of halftoning a continuous-level im... View full abstract»

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  • Jitter accommodation in token-passing ring LANs

    Publication Year: 1985 , Page(s): 580 - 587
    Cited by:  Patents (1)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (660 KB)  

    In a token-passing ring Local Area Network (LAN) each message accumulates phase jitter as it travels around the ring. Unlike typical digital transmission systems, which tend to have random data traffic, ring systems carrying computer-generated traffic may have long strings of repetitive-pattern data. This traffic produces a jitter amplitude which is a function of the message statistics and the tra... View full abstract»

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  • Analysis of the holding current in CMOS latch-up

    Publication Year: 1985 , Page(s): 588 - 592
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (488 KB)  

    The holding current in CMOS latch-up with or without well and/or substrate bias has been examined. Measurements indicate that the holding current increases significantly with reverse bias and low shunting base resistance. It is shown that a previous equation for the holding current is inaccurate, and a new equation for holding current with bias is presented. View full abstract»

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  • Recent papers by IBM authors

    Publication Year: 1985 , Page(s): 593 - 610
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (1495 KB)  

    The information listed here is supplied by the Institute for Scientific Information. Reprints of the papers may be obtained by writing directly to the author. Papers are listed alphabetically by author. View full abstract»

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  • Recent IBM patents

    Publication Year: 1985 , Page(s): 611 - 618
    Save to Project icon | PDF file iconPDF (503 KB)  
    Freely Available from IEEE
  • Author index for papers in Volume 29

    Publication Year: 1985 , Page(s): 619 - 621
    Save to Project icon | PDF file iconPDF (197 KB)  
    Freely Available from IEEE
  • Subject index for papers in Volume 29

    Publication Year: 1985 , Page(s): 622 - 625
    Save to Project icon | PDF file iconPDF (276 KB)  
    Freely Available from IEEE

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