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IBM Journal of Research and Development

Issue 2 • Date April 1961

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Displaying Results 1 - 10 of 10
  • Table Look-up Procedures in Language Processing—Part I: The Raw Text

    Page(s): 86 - 92
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (780 KB)  

    A method of addressing memories is described which is very powerful in the processing of natural languages, where the arithmetic or logical operations are either nonexistent or do not lend themselves to algorithmic description. The main feature is the guarantee of initiation of an exhaustive search for a linguistic word at a point just beyond the desired address. Sequential search backwards not only locates an address if it is there but also provides identification of a longest match first. The method is further extended to provide “conditional” addressing by prefixing subsequent addresses from information obtained in earlier searches. View full abstract»

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  • Phase Reversal Data Transmission System for Switched and Private Telephone Line Applications

    Page(s): 93 - 105
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (950 KB)  

    A phase reversal data transmission system is described, capable of operating at 2000 bauds over private telephone lines and at 1200 bauds over switched networks. The advantages and limitations of the system are discussed from a theoretical and practical standpoint. The clocking problem in data transmission is considered and several approaches are indicated. A summary is given of extensive field tests over switched and private lines in Europe and on private (SAGE) lines in the U.S. View full abstract»

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  • A Magnetic Associative Memory

    Page(s): 106 - 121
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1284 KB)  

    This paper describes a computer storage system in which data flows in and out of the memory on the basis of content rather than location (address). In addition, a small experimental model of this system is described, using ferrite cores as novel associative memory storage elements. View full abstract»

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  • Acoustic-Mode Scattering of Holes

    Page(s): 122 - 131
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (779 KB)  

    Matrix elements are calculated for acoustic-mode scattering of holes in the valence band structure typified by germanium. Whitfield's generalization of the deformation potential theorem is used to calculate the electron-phonon interaction; his method is, however, extended to include the spin-lattice coupling. A general expression for the electron-phonon interaction matrix element is obtained, and calculations are presented for some special directions in k-space. View full abstract»

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  • Analysis of a Basic Queuing Problem Arising in Computer Systems

    Page(s): 132 - 140
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (705 KB)  

    A model which describes a basic junction, or queuing structure, arising in a general computing system is subjected to a mathematical analysis. The results consist of several formulas describing the performance of various parts of the system. The feasibility in analyzing general queuing problems in this manner is stated, together with the results of a Monte Carlo simulation used for comparison purposes. View full abstract»

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  • A Direct Digital Method of Power Spectrum Estimation

    Page(s): 141 - 156
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1237 KB)  

    This paper discusses a method of digital power spectrum estimation involving the direct combination of the sample time function with sines and cosines. This treatment is in contrast to the normal indirect digital method which proceeds through the intermediary of the autocovariance function. All the practical design details necessary for the planning of a spectral estimation program are treated. View full abstract»

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  • The Dynamics of a Subharmonic Oscillator with Linear Dissipation

    Page(s): 157 - 161
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (516 KB)  

    A mathematical analysis of the dynamic behavior of subharmonic oscillators (parametrons) is made assuming a nonlinear reactance but a linear dissipation or resistance. Simple equations of motion for the subharmonic and pump amplitudes are derived in the quasistatic, or high-Q, approximation. Numerical solutions are obtained for two cases. The first shows the subharmonic amplitude changing from a small value to its steady state value when a constant pump signal is applied. The second shows decay when the pump signal is removed. View full abstract»

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  • IBM Technical Papers Published in Other Journals

    Page(s): 162 - 169
    Save to Project icon | PDF file iconPDF (954 KB)  
    Freely Available from IEEE
  • Recent IBM Patents

    Page(s): 170 - 171
    Save to Project icon | PDF file iconPDF (264 KB)  
    Freely Available from IEEE
  • Authors

    Page(s): 172 - 173
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    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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Meet Our Editors

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