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IBM Journal of Research and Development

Issue 4 • Date July 1970

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Displaying Results 1 - 19 of 19
  • Coding for Error Control in a Computer-Manufacturer's Environment: A Foreword

    Publication Year: 1970, Page(s): 342
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | PDF file iconPDF (244 KB)
    Freely Available from IEEE
  • Coding Schemes for Reduction of Intersymbol Interference in Data Transmission Systems

    Publication Year: 1970, Page(s):343 - 353
    Cited by:  Papers (8)  |  Patents (20)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1064 KB)

    Various coding schemes and their effects on intersymbol interference in pulse amplitude modulation systems are discussed. First, the relation between imperfections in the baseband-equivalent channel and intersymbol interference is clarified and applied to explain the effect of correlative level coding and Gorog's frequency concept codes in reducing intersymbol interference. Another coding scheme i... View full abstract»

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  • Introduction to Pseudoternary Transmission Codes

    Publication Year: 1970, Page(s):354 - 367
    Cited by:  Papers (29)  |  Patents (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1047 KB)

    This paper describes many of the pseudoternary (PT) codes (twinned, bipolar, partial response, etc.) used in data transmission. In these, binary information is transmitted through three-level rather than binary pulse codes for controlling the power distribution in the frequency spectrum, improving clock recovery, allowing error detection or for just increasing the binary data rate. Linear and nonl... View full abstract»

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  • Application of Partial-response Channel Coding to Magnetic Recording Systems

    Publication Year: 1970, Page(s):368 - 375
    Cited by:  Papers (129)  |  Patents (60)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (684 KB)

    A magnetic recording channel can be regarded as a “partial-response” channel because of its inherent differentiation in the readback process. The conventional NRZI method of recording is shown to be equivalent to the “precoding” of this particular partial-response channel, the purpose of which is to limit the propagation of error in the channel output. Using this new vi... View full abstract»

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  • Sequence-state Methods for Run-length-limited Coding

    Publication Year: 1970, Page(s):376 - 383
    Cited by:  Papers (60)  |  Patents (27)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (700 KB)

    Methods are presented for the encoding of information into binary sequences in which the number of ZEROS occurring between each pair of successive ONES has both an upper and a lower bound. The techniques, based on the state structure of the constraints, permit the construction of short, efficient codes with favorable error-propagation-limiting properties. View full abstract»

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  • Error Correction for IBM 800-bit-per-inch Magnetic Tape

    Publication Year: 1970, Page(s):384 - 389
    Cited by:  Papers (7)  |  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (624 KB)

    The 800-bit-per-inch magnetic tape units that are components of IBM System/360 can correct error bursts of unlimited length in any one of their nine tape tracks. The correction technique employs a modified cyclic code in conjunction with a parity bit in each nine-bit character. There are nine check bits in the modified cyclic code and these form a check character at the end of every record. To per... View full abstract»

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  • Orthogonal Latin Square Codes

    Publication Year: 1970, Page(s):390 - 394
    Cited by:  Papers (33)  |  Patents (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (478 KB)

    A new class of multiple-error correcting codes has been developed. Since it belongs to the class of one-step-decodable majority codes, it can be decoded at an exceptionally high speed. This class of codes is derived from a set of mutually orthogonal Latin squares. This mutually orthogonal property provides a class of codes having a unique feature of “modularity.” The parity check mat... View full abstract»

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  • A Class of Optimal Minimum Odd-weight-column SEC-DED Codes

    Publication Year: 1970, Page(s):395 - 401
    Cited by:  Papers (169)  |  Patents (36)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (563 KB)

    The class of codes described in this paper is used for single-error correction and double-error detection (SEC-DED). It is equivalent to the Hamming SEC-DED code in the sense that for a specified number k of data bits, the same number of check bits r is used. The minimum odd-weight-column code is suitable for applications to computer memories or parallel systems. A computation indicates that this ... View full abstract»

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  • b-Adjacent Error Correction

    Publication Year: 1970, Page(s):402 - 408
    Cited by:  Papers (40)  |  Patents (21)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (581 KB)

    A high-speed method is derived for single-symbol error correcting Reed-Solomon and Hamming type codes. A matrix description is used for implementation of the codes, in which single-error correction in the Galois field 2b corresponds to correcting a block of b bits in a binary field. The resulting codes correct not only single-bit errors but also single clusters of b-adjacent-bit errors. View full abstract»

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  • Error Control for Terminals with Human Operators

    Publication Year: 1970, Page(s):409 - 416
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (696 KB)

    The man-machine interface at any terminal in a computer system is a likely source of error and can be regarded as a noisy channel. Certain data, such as ID numbers, can be precoded to protect against most-likely errors, including transposition of adjacent symbols and substitutions, as well as deletions and insertions. This paper first considers certain basic requirements for error detection with m... View full abstract»

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  • Three Measures of Decoder Complexity

    Publication Year: 1970, Page(s):417 - 425
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (899 KB)

    Three measures of the complexity of error correcting decoders are considered, namely, logic complexity, computation time and computational work (the number of logical operations). Bounds on the complexity required with each measure to decode with probability of error Pe at code rate R are given and the complexity of a number of ad hoc decoding procedures is examined. View full abstract»

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  • An Analysis of the Effectiveness of Hybrid Transmission Schemes

    Publication Year: 1970, Page(s):426 - 433
    Cited by:  Papers (32)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (745 KB)

    A comparison is made of the performance of pure retransmission, forward error correction and hybrid (error detecting/correcting) schemes for data transmission in a noisy (probability of error, P > 10−4) binary symmetric channel. The performance calculations are based on the use of BCH codes for error detection and correction up to the full correction capability of the code... View full abstract»

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  • Maximal Group Codes with Specified Minimum Distance

    Publication Year: 1970, Page(s):434 - 443
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (814 KB)

    All n-digit maximal block codes with a specified minimum distance d such that 2d ≥ n can be constructed from the Hadamard matrices. These codes meet the Plotkin bound. In this paper we construct all maximal group codes in the region 2d ≥ n, where d is a specified minimum distance and n is the number of digits per code word. Unlike the case of block codes, the Plotkin upper limit, in ... View full abstract»

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  • Low Energy Electron Diffraction (LEED) Spectra: Aluminum

    Publication Year: 1970, Page(s):444 - 452
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (756 KB)

    The intensities of low energy electron beams specularly and nonspecularly diffracted from {100}, {110} and {111} surfaces of aluminum have been measured in a display-type LEED system as functions of electron energy, angle of incidence and azimuthal angle. Several of the measured and normalized spectra are presented, and the procedures followed in aligning ... View full abstract»

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  • Silicon Defect Structure Induced by Arsenic Diffusion and Subsequent Steam Oxidation

    Publication Year: 1970, Page(s):453 - 460
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1070 KB)

    Misfit dislocation nets are known to occur when very high amounts of phosphorus and boron are diffused into silicon single-crystal wafers. Diffusion of arsenic in silicon is not known to produce such dislocations. Through transmission electron microscopy it is shown in this paper that diffusion of high amounts (up to 1.6 × 1021 atoms/cm3) of arsenic creates Frank hexag... View full abstract»

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  • Reduction of Electromigration in Aluminum Films by Copper Doping

    Publication Year: 1970, Page(s):461 - 463
    Cited by:  Papers (24)  |  Patents (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (432 KB)

    We have found that the lifetime of aluminum films subjected to high current densities at elevated temperatures can be increased by the addition of copper. Previous studies have indicated that the failure mechanism is a combination of electromigration-induced phenomena, including nucleation and growth of voids, which are gated primarily by material transport along grain boundaries. On the basis of ... View full abstract»

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  • Recent Papers by IBM Authors

    Publication Year: 1970, Page(s):464 - 468
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (561 KB)

    Reprints of the papers listed here may usually be obtained most eficiently by writing directly to the authors. The authors' IBM divisions and locations are identified as follows: ASDD is the Advanced Systems Development Division; CD, Components Division; DPD, Data Processing Division; FED, Field Engineering Division; FSD, Federal Systems Division; GSD, General Systems Division; RES, Research Divis... View full abstract»

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  • Patents Recently Issued to IBM Inventors

    Publication Year: 1970, Page(s):469 - 471
    IEEE is not the copyright holder of this material | PDF file iconPDF (384 KB)
    Freely Available from IEEE
  • Authors

    Publication Year: 1970, Page(s):472 - 474
    IEEE is not the copyright holder of this material | PDF file iconPDF (425 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