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IBM Journal of Research and Development

Issue 2 • Date March 1967

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Displaying Results 1 - 17 of 17
  • Laser-pumped Stimulated Emission from Organic Dyes: Experimental Studies and Analytical Comparisons

    Publication Year: 1967, Page(s):130 - 148
    Cited by:  Papers (28)  |  Patents (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (956 KB)

    Stimulated emission spectra of two organic dyes, chloro-aluminum phthalocyanine (CAP) and 3,3′-diethylthiatricarbocyanine iodide (DTTC) are compared. Giant-pulse ruby laser excitation was used in both cases. An end pumping configuration employed with DTTC resulted in narrow beam divergences and high conversion efficiencies. For CAP, the oscillating transition is one which terminates on an e... View full abstract»

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  • Flashlamp Excitation of Organic Dye Lasers: A Short Communication

    Publication Year: 1967, Page(s): 148
    Cited by:  Papers (11)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (202 KB)

    Pumping with a specially constructed flashlamp rather than a giant pulse laser, we have just observed stimulated emission from three of the five dyes considered in the addendum to Ref. 1. In the table below we give some observations and results for the dyes in which lasing was thus achieved: Acridine Red, Rhodamine 6G, and Fluorescein View full abstract»

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  • A 110-Nanosecond Ferrite Core Memory

    Publication Year: 1967, Page(s):153 - 161
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (661 KB)

    The design of a large, very-high-speed ferrite memory is described. The memory has a capacity of 8192 words, 72 bits per word, and has a cycle time of 110 nanoseconds and an access time of 67 nanoseconds. The storage devices are miniature ferrite cores, 0.0075 by 0.0123 by 0.0029 inches, and are operated in a two-core-per-bit destructive read-out mode. A planar array geometry with cores resting on... View full abstract»

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  • A Very-High-Speed, Nondestructive-Read Magnetic Film Memory

    Publication Year: 1967, Page(s):162 - 168
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (544 KB)

    A very-high-speed thin magnetic film memory has been designed and built as a cross sectional test model for 140,000 bits. It can be operated in the NDRO mode with a 20-nsec read cycle time and a 30-nsec access time, and it can be read 65 nsec after the beginning of a write operation. View full abstract»

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  • Device and Array Design for a 120-Nanosecond Magnetic Film Main Memory

    Publication Year: 1967, Page(s):169 - 178
    Cited by:  Papers (4)  |  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (769 KB)

    Device and array design considerations are described for a manufacturable 120-nsec cycle magnetic film memory containing 600,000 bits in the basic operating module. Worst-case testing is done in such a way as to provide quantitative values for such effects as adjacent bit-line stray field, ground-plane current spreading, flux trapping in metallic ground planes and strip lines, and magnetic-keeper ... View full abstract»

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  • Direct Digital Processor Control of Stepping Motors

    Publication Year: 1967, Page(s):179 - 188
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (583 KB)

    This paper describes the concept for implementing direct computer control of stepping motors. The design approach is based on using the computer to close a minor loop around the motor. The discussion includes both full and partial computer control, and the results show that the closed-loop stepping motor is well suited to such applications. View full abstract»

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  • Digital Simulation Applied to a Photo-Optical System

    Publication Year: 1967, Page(s):189 - 194
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (453 KB)

    The validity of the Image Forming Systems Simulator, IMSIM/1, as a means of simulating multiple-stage photo-optical systems has been determined. IMSIM/1 was used to simulate a three-stage system consisting of a microfilm camera (first stage), followed by the photo-optical subsystem of a developmental image storage and retrieval system (second and third stage). Fine line targets were processed thro... View full abstract»

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  • Technical Papers by IBM Authors Published Recently in Other Journals

    Publication Year: 1967, Page(s):195 - 207
    IEEE is not the copyright holder of this material | PDF file iconPDF (850 KB)
    Freely Available from IEEE
  • Patents Recently Issued to IBM Inventors

    Publication Year: 1967, Page(s):208 - 209
    IEEE is not the copyright holder of this material | PDF file iconPDF (309 KB)
    Freely Available from IEEE
  • Authors

    Publication Year: 1967, Page(s):210 - 212
    IEEE is not the copyright holder of this material | PDF file iconPDF (281 KB)
    Freely Available from IEEE
  • Special Section on Difference Equations [Foreword]

    Publication Year: 1967, Page(s): 213
    IEEE is not the copyright holder of this material | PDF file iconPDF (148 KB)
    Freely Available from IEEE
  • Authors of the Paprs on Difference Equations

    Publication Year: 1967, Page(s): 214
    IEEE is not the copyright holder of this material | PDF file iconPDF (190 KB)
    Freely Available from IEEE
  • On the Partial Difference Equations of Mathematical Physics

    Publication Year: 1967, Page(s):215 - 234
    Cited by:  Papers (74)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1024 KB)

    Problems involving the classical linear partial differential equations of mathematical physics can be reduced to algebraic ones of a very much simpler structure by replacing the differentials by difference quotients on some (say rectilinear) mesh. This paper will undertake an elementary discussion of these algebraic problems, in particular of the behavior of the solution as the mesh width tends to... View full abstract»

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  • Hyperbolic Difference Equations: A Review of the Courant-Friedrichs-Lewy Paper in the Light of Recent Developments

    Publication Year: 1967, Page(s):235 - 238
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (412 KB)

    The portion of the Courant-Friedrichs-Lewy paper [Math. Ann. 100, 32 (1928)] that was devoted to hyperbolic difference equations is critically reviewed in terms of its basic contribution to the numerical solution of partial differential equations. Some subsequent developments are then discussed, including recent literature related to the von Neumann condition, some irreversible schemes, generaliza... View full abstract»

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  • On Difference Methods for Parabolic Equations and Alternating Direction Implicit Methods for Elliptic Equations

    Publication Year: 1967, Page(s):239 - 243
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (508 KB)

    Some aspects are discussed of the development of the theory of difference approximations to parabolic equations in its relation to the basic development of difference methods for hyperbolic and elliptic equations by Courant, Friedrichs and Lewy, [Math. Ann. 100, 32 (1928)]. The present paper also deals with the related problem of establishing the convergence of alternating direction implicit metho... View full abstract»

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  • Elliptic Equations

    Publication Year: 1967, Page(s):244 - 247
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (343 KB)

    A brief review is given of the literature on numerical methods for elliptic problems as related to the ideas introduced by Courant, Friedrichs and Lewy in the fundamental paper published in Math. Ann. 100, 32 (1928). The discussion shows how the finite-difference methods have subsequently been extended and applied to higher order elliptic problems and how the recent literature has reported methods... View full abstract»

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  • Contents of previous two issues

    Publication Year: 1967, Page(s):248 - 249
    IEEE is not the copyright holder of this material | PDF file iconPDF (235 KB)
    Freely Available from IEEE

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IBM T. J. Watson Research Center