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IBM Journal of Research and Development

Issue 2 • Date March 1965

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Displaying Results 1 - 13 of 13
  • Hazard Detection in Combinational and Sequential Switching Circuits

    Publication Year: 1965 , Page(s): 90 - 99
    Cited by:  Papers (96)  |  Patents (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (882 KB)  

    This paper is concerned with a unified approach to the detection of hazards in both combinational and sequential circuits through the use of ternary algebra. First, hazards in a combinational network resulting from the simultaneous changing of two or more inputs are discussed. A technique is described that will detect hazards resulting from both single- and multiple-input changes. The various types of hazards connected with gate-type sequential circuits are also discussed, and a general technique is described that will detect any type of hazard or race condition that could result in an incorrect terminal state. This technique could be easily implemented in a computer program which would be capable of detecting hazards in circuits containing hundreds of logic blocks. View full abstract»

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  • Coincidence Counter Models with Applications to Photographic Detection Theory

    Publication Year: 1965 , Page(s): 100 - 107
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (515 KB)  

    Various types of counter models have been treated in the literature over the past twenty years. In all these models the counter mechanism involves a fixed or random dead time following a registered event. In this paper a different type of counter mechanism is introduced in which the occurrence of two or more input events within a relatively short time is required to produce a registered (output) event. This model of an “R-fold coincidence counter” is applied to the development of grains in a photographic emulsion for both low-intensity and high-intensity reciprocity failure. View full abstract»

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  • On Plane Blazed Gratings

    Publication Year: 1965 , Page(s): 108 - 117
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (607 KB)  

    The Fraunhofer patterns of blazed gratings are derived on the basis of a scalar theory which includes the non-linear dependence of the obliquity factor and the phase modulation on the spatial frequencies defining the positions of the source and of the observer. The solution based on the usual ‘linear communications’ theory is compared with one based on the more general non-linear theory; it is shown that the former is meaningful only in the neighborhood of the blaze wavelength. The behavior of blazed gratings is examined in the light of non-linear theory in the region away from the blaze wavelength. It is shown that the envelope function describing the amplitude distribution due to a single groove depends on the single parameter defining half the phase difference between the two edges of a single diffracting facet. It is also shown that certain wavelengths are missing from the zero order and that ‘dark’ lines exist into which no light of any order is transmitted. A useful maximum for the aspect ratio is derived. The Littrow and spectrograph configurations are examined in some detail. View full abstract»

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  • Demagnetization of Flat Uniaxial Thin Films Under Hard Direction Drive

    Publication Year: 1965 , Page(s): 118 - 123
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (369 KB)  

    The demagnetizing fields are derived for all points of flat uniaxial thin films under various drive fields. The derivation is accomplished by breaking up the flat film into a number of sheets in superposition and integrating their individual contributions to the demagnetizing fields. The scheme is self-consistent in that the magnetization results as a consequence of the derivation, and need not be assumed. Further, the accuracy does not depend on the position with respect to the edges, but rather on the number of sheets. The general approach to the problem is discussed briefly and the final equation for a rectangular geometry given. The discussion is concerned with one-dimensional examples, demonstrating the somewhat unexpected form of the demagnetizing fields under various hard axis drive conditions. Single bits as well as continuous films of Permalloy driven by uniform fields and multiple strip lines are treated. The effect of registration on the demagnetization is also discussed. View full abstract»

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  • Average Motion Times of Positioners in Random Access Devices

    Publication Year: 1965 , Page(s): 124 - 133
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (555 KB)  

    An analysis is made of the average motion times of mechanical positioners based on trapezoidal velocity vs time curves. The results are plotted in terms of dimensionless motion parameters. It is shown that average motion time may be optimized by balancing acceleration and velocity in a proper way. The selection of optimum transmission ratios between motor and load is discussed and demonstrated in an example. View full abstract»

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  • Sheet Thermoforming of a Superplastic Alloy

    Publication Year: 1965 , Page(s): 134 - 136
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (383 KB)  

    Ordinary metals and alloys have not heretofore been shaped by the sheet thermoforming techniques so advantageously used by the plastics industry. Although a polymeric material may undergo a manifold increase in surface area during vacuum or pressure forming, metal or alloy sheet invariably fails by localized deformation and thinning at relatively low strains when subjected to tensile plastic deformation. Recent reports of “superplastic” behavior in metals and alloys1,2 include examples of extraordinary amounts of uniform tensile elongation. This communication reports the initial results of efforts to utilize a superplastic alloy in a laboratory vacuum-forming operation. View full abstract»

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  • A New Method for Frequency-Division Multiplexing, and Its Integration with Time-Division Switching

    Publication Year: 1965 , Page(s): 137 - 140
    Cited by:  Papers (6)  |  Patents (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (326 KB)  

    A new method to achieve frequency-division multiplexing has been determined. The basis of this method is a new heterodyning scheme, which operates in conjunction with a generalized concept of resonant transfer. Besides achieving frequency-division multiplexing, these concepts, in combination with time-division switching, are the basis for a system that seems to be more economical than conventional combinations of these capabilities. Such a combination is required to effect time-division switching into and out of frequency-divided trunk lines. The basic reason that this integrated system offers the potential of such economy is that the time-division switches are made to serve two purposes. In addition to performing their normal switching function, they also serve a purpose in the frequency multiplexing and demultiplexing operations. Laboratory analysis and development have thus far validated the feasibility of these concepts. View full abstract»

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  • Electrodeposition of Stress-Insensitive Ni-Fe and Ni-Fe-Cu Magnetic Alloys

    Publication Year: 1965 , Page(s): 141 - 146
    Cited by:  Papers (6)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (430 KB)  

    A thorough knowledge and a very close check of the parameters affecting the characteristics of the deposits enable one to obtain zero Ni-Fe deposits having zero magnetostriction. Addition of Cu to Ni-Fe deposits makes it possible to double the tolerances imposed upon these parameters and to improve the magnetic properties of these deposits, especially in very-high-frequency applications. View full abstract»

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  • Peculiar Domain Behavior in Thin, Magnetic Ni-Fe Double Films

    Publication Year: 1965 , Page(s): 147 - 149
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (265 KB)  

    In a previous letter1 it was shown that in double Permalloy films, consisting of two Permalloy layers separated by a nonmagnetic layer, wall structures occur which differ from those observed in single films. In particular, in a double film (400 Å Ni-Fe, 200 Å SiO, 400 Å Ni-Fe) NCel walls and perturbation walls were observed instead of the cross-tie walls normally occurring in Ni-Fe layers of 400 Å. View full abstract»

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  • Technical Papers by IBM Authors Published Recently in Other Journals

    Publication Year: 1965 , Page(s): 150 - 162
    Save to Project icon | PDF file iconPDF (722 KB)  
    Freely Available from IEEE
  • Recent IBM Patents

    Publication Year: 1965 , Page(s): 163 - 164
    Save to Project icon | PDF file iconPDF (172 KB)  
    Freely Available from IEEE
  • Authors

    Publication Year: 1965 , Page(s): 165 - 167
    Save to Project icon | PDF file iconPDF (199 KB)  
    Freely Available from IEEE
  • Contents of previous two issues

    Publication Year: 1965 , Page(s): 168 - 169
    Save to Project icon | PDF file iconPDF (230 KB)  
    Freely Available from IEEE

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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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Clifford A. Pickover
IBM T. J. Watson Research Center