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IBM Journal of Research and Development

Issue 3 • Date July 1962

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Displaying Results 1 - 15 of 15
  • Rectification of Satellite Photography by Digital Techniques

    Page(s): 290 - 305
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1611 KB)  

    Sample photographs from the TIROS I Weather Satellite have been successfully transformed into a Mercator projection using automatic digital techniques. Mathematical formulas expressing the relation between the photoplane and the Mercator projection have been derived, and a computer program has been written to efficiently manipulate a “digital photograph” in accordance with the formulas. View full abstract»

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  • Multiple Input-Output Links in Computer Systems

    Page(s): 306 - 328
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1492 KB)  

    An algorithm is developed for the analysis and design of computing systems having a multiplicity of concurrent and independent information sources and a lesser number of input channels to the processing elements of a digital computer; the input-output links work simultaneously with the processing and computing elements of the system. Utilizing this algorithm, such problems pertaining to the amount of hardware and the interconnection of its components can be resolved. For an optimum system design, its parameters are subject to two major criteria, i.e., the amount of information transmitted to the central processing elements per unit time, and the degree of overlapping of input output operations with computing (or other processing operations) that can be attained. Part I of this paper is devoted to information sources of the sequential access, serial-by-character (or-bit) transmission class. Magnetic tape units are specifically dealt with. With minor modifications the method is applicable to other information sources of the same class. In Part I, three fundamental system configurations are discussed and results of computations are summarized. In Part II, information sources of the quasi-random and random access class are investigated within the framework established in Part I. Disk files were selected as a specific representative of the quasi-random and random access information sources. View full abstract»

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  • Diffusion of Gas from a Liquid into an Expanding Bubble

    Page(s): 329 - 337
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (701 KB)  

    The growth of a bubble within a volume of isothermal viscous liquid containing uniformly distributed dissolved gas is considered. The problem of characterizing this growth-by-mass-transfer is reduced to an integro-differential equation for the bubble radius as a function of time, and a computer solution is obtained. The initial and final stages of growth are treated analytically. View full abstract»

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  • Spin Absorption Spectra

    Page(s): 338 - 347
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (760 KB)  

    Spin systems exhibit a whole spectrum of absorption lines when in small constant external magnetic fields giving Zeeman energies comparable to internal interaction energies. With such small constant magnetic fields, power is absorbed from an alternating magnetic field at zero frequency, at the Larmor frequency, and at harmonics of the Larmor frequency, both for perpendicular- and parallel-field configurations. The calculation of this spectrum for spin systems in powdered materials is the main purpose of this paper. Both magnetic dipole-dipole and electric quadrupole internal interactions are considered and treated as second-order perturbations on the Zeeman interaction. The intensities of the two absorption lines that occur at the Larmor frequency and double the Larmor frequency are obtained for the parallel-field case. The intensity, frequency shift, and second moment of the Larmor line, and the intensities of the lines that occur at zero frequency and double the Larmor frequency, are obtained for the perpendicular-field case. The second-order calculation for powdered materials gives results which are identical within a constant factor for both dipole-dipole and quadrupole interactions. View full abstract»

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  • An Experiment on the Effect of Particle Orientation on Peak Shift in Magnetic Tapes

    Page(s): 348 - 352
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (620 KB)  

    One of the limiting factors in high-density recording on magnetic tape is the phenomenon of peak shift. With the NRZI code (flux change on a one, no flux change on a zero) this means that the reproduced signals from two successive ones preceded and followed by zeros are separated in time by more than the natural bit period. The peaks in the signal output from the two ones are thus shifted outwards. An experiment is described in which the peak shift is measured in particle-oriented tape as a function of the angle θ between the direction of recording and the direction of orientation. The dc hysteresis properties of the tape were also measured as a function of θ. It was found that the peak shift had a minimum when θ was approximately 65° for the tape and recording head used in this experiment. At this angle the remanence-coercivity was high, while the coercivity and the ratio of remanence to saturation intensity were low. Qualitative explanations of these results are offered and their significance is briefly discussed. View full abstract»

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  • A “Logical Pattern” Recognition Program

    Page(s): 353 - 360
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (820 KB)  

    A description is given of an IBM 7090 program which searches for “logical patterns” in a set of input samples. The program was tested on a character recognition problem, where it designed a recognition system whose error rate and hardware requirements are compared to those of a system designed by humans. This program is intended to be used as a research tool to discover certain kinds of patterns in data and as a step in the direction of automatic logic design for some character recognition problems. View full abstract»

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  • Optical Mixing of Coherent and Incoherent Light [Letter to the Editor]

    Page(s): 361 - 362
    Save to Project icon | PDF file iconPDF (323 KB)  
    Freely Available from IEEE
  • Fluorescence of Europium Tungstate [Letter to the Editor]

    Page(s): 363 - 364
    Save to Project icon | PDF file iconPDF (282 KB)  
    Freely Available from IEEE
  • A Note on the Nature of RNA Codes [Letter to the Editor]

    Page(s): 365 - 367
    Save to Project icon | PDF file iconPDF (341 KB)  
    Freely Available from IEEE
  • Partial-Switching Processes in Thin Magnetic Films [Letter to the Editor]

    Page(s): 368 - 371
    Save to Project icon | PDF file iconPDF (444 KB)  
    Freely Available from IEEE
  • Direct Observation of Dislocation Loops in Arsenic-Doped Germanium [Letter to the Editor]

    Page(s): 372 - 374
    Save to Project icon | PDF file iconPDF (403 KB)  
    Freely Available from IEEE
  • Electron Beam Microanalysis of Germanium Tunnel Diodes [Letter to the Editor]

    Page(s): 375 - 377
    Save to Project icon | PDF file iconPDF (384 KB)  
    Freely Available from IEEE
  • IBM Technical Papers Published Recently in Other Journals

    Page(s): 378 - 388
    Save to Project icon | PDF file iconPDF (1182 KB)  
    Freely Available from IEEE
  • Recent IBM Patents

    Page(s): 389 - 390
    Save to Project icon | PDF file iconPDF (257 KB)  
    Freely Available from IEEE
  • Authors

    Page(s): 391 - 392
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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.

Full Aims & Scope

Meet Our Editors

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