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IBM Journal of Research and Development

Issue 1 • Date Jan. 1981

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Displaying Results 1 - 12 of 12
  • Network Problem-Determination Aids in Microprocessor-Based Modems

    Publication Year: 1981 , Page(s): 3 - 16
    Cited by:  Papers (2)  |  Patents (7)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (946 KB)  

    Recent significant developments in large-scale integration (LSI) and in digital signal-processing techniques have combined to provide the base for a new generation of modems. LSI microprocessors now have the characteristics and performance to provide superior modem function as well as a design base for the addition of new function. The extendability afforded by a microprocessor-based modem design ... View full abstract»

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  • A 2400-Bit/s Microprocessor-Based Modem

    Publication Year: 1981 , Page(s): 17 - 24
    Cited by:  Papers (2)  |  Patents (2)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (612 KB)  

    This paper describes the main characteristics of a new microprocessor-implemented 2400-bit/s data modem, the IBM 3863. In addition to the execution of signal processing tasks, the microprocessor provides a variety of other significant functions such as diagnostics and aids in network problem determination. The lack of hardware multiplication capability imposes certain constraints in the design of ... View full abstract»

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  • Coupled Lossy Transmission Line Characterization and Simulation

    Publication Year: 1981 , Page(s): 25 - 41
    Cited by:  Papers (108)  |  Patents (11)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (1143 KB)  

    It has been shown that the frequency domain solution of the coupled lossy transmission line differential equations has a similar appearance to that of the single line. The frequency-dependent n × n characteristic admittance matrix Y0 and propagation matrix Γ can be obtained from network analyzer insertion loss data treating the coupled transmission lines as a 2n-port netwo... View full abstract»

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  • [Pt]Polypyrrole: A New Organic Electrode Material

    Publication Year: 1981 , Page(s): 42 - 50
    Cited by:  Patents (5)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (646 KB)  

    Films of BF4-doped polypyrrole grown on platinum, hereafter termed [Pt]polypyrrole, were used as electrodes in a series of reactions. These organic electrodes are found to be quite stable and nonporous; they generally do not perturb the redox reactions of dissolved species and they display rapid surface-substrate electron-transfer kinetics. The polypyrrole films are sensitive to the pre... View full abstract»

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  • Conducting Polymers: A Review of Recent Work

    Publication Year: 1981 , Page(s): 51 - 57
    Cited by:  Papers (1)  |  Patents (3)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (645 KB)  

    The conductivities of all the currently reported conducting polymers are compared to those of the classical metals. The requirements for a technologically useful conducting polymer are considered and the degree to which existing conducting polymers meet these requirements is evaluated. The mechanism of doping is discussed together with the final state of the dopant and the polymer. The available s... View full abstract»

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  • Computer Simulation of High-Resolution Electron Micrographs Using Dynamical Electron Scattering

    Publication Year: 1981 , Page(s): 58 - 70
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (1110 KB)  

    A system of computer programs has been implemented that calculates both high-resolution images and diffraction patterns of generalized objects for the conventional transmission electron microscope. Multi-slice dynamical electron scattering of 256 × 256 = 65,536 beams is incorporated into these programs, which allows Bragg reflections and the diffuse scattering contributions between these re... View full abstract»

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  • Tomographic Reconstruction of Ultrasonic Attenuation with Correction for Refractive Errors

    Publication Year: 1981 , Page(s): 71 - 82
    Cited by:  Papers (8)  |  Patents (7)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (804 KB)  

    The nonionizing and noninvasive characteristics of ultrasonics promote its increasing use in medical applications. Computerized ultrasonic attenuation tomography is one area where medically significant images may be reconstructed for diagnostic purposes. The objective of this work is to make an initial correction for refraction error and other problems present in computerized ultrasonic tomography... View full abstract»

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  • A Number Representation Convertor for Magnetic Bubble String Comparators

    Publication Year: 1981 , Page(s): 83 - 87
    Cited by:  Papers (1)
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (388 KB)  

    Conventionally, there are four common ways to represent negative numbers, namely, 1's-complement, 2's-complement, signed-magnitude, and excess-2m−1. In all these representations except the last one (excess-2m−1), 1 is used as the sign bit to denote negative numbers. However, in a recently reported magnetic bubble device, using 1 as the sign bit for negative numb... View full abstract»

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  • Recent Papers by IBM Authors

    Publication Year: 1981 , Page(s): 88 - 96
    Save to Project icon | Click to expandAbstract | PDF file iconPDF (773 KB)  

    First Page of the Article
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  • Recent IBM Patents

    Publication Year: 1981 , Page(s): 97 - 99
    Save to Project icon | PDF file iconPDF (260 KB)  
    Freely Available from IEEE
  • Authors

    Publication Year: 1981 , Page(s): 100 - 102
    Save to Project icon | PDF file iconPDF (337 KB)  
    Freely Available from IEEE
  • Errata [Erratum]

    Publication Year: 1981 , Page(s): 103
    Save to Project icon | PDF file iconPDF (196 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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Editor-in-Chief
Clifford A. Pickover
IBM T. J. Watson Research Center