IBM Journal of Research and Development

Issue 2 • April 1959

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Displaying Results 1 - 18 of 18
  • Direct Measurement of the Angular Dependence of the Imaginary Part of the Atomic Scattering Factor of Germanium

    Publication Year: 1959, Page(s):106 - 113
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (547 KB)

    In the dynamical theory of the anomalous transmission of x-rays through perfect thick crystals, the ratio of transmitted intensity to incident intensity depends upon [1 − Kf″Ge(θhkl)/f″Ge(0°)] exponentially. Here K is the polarization factor and the f″Ge(θhkl) and f″Ge(0°... View full abstract»

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  • Finite Automata and Their Decision Problems

    Publication Year: 1959, Page(s):114 - 125
    Cited by:  Papers (120)  |  Patents (24)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (739 KB)

    Finite automata are considered in this paper as instruments for classifying finite tapes. Each one-tape automaton defines a set of tapes, a two-tape automaton defines a set of pairs of tapes, et cetera. The structure of the defined sets is studied. Various generalizations of the notion of an automaton are introduced and their relation to the classical automata is determined. Some decision problems... View full abstract»

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  • Interatomic-Force Constants from a Central-Force Law

    Publication Year: 1959, Page(s):126 - 131
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (417 KB)

    Interatomic-force constants may be predicted from standard central-force laws using thermodynamic data. For the three cases where diffraction data are available (aluminum, copper, and iron) the predicted values agree within an order of magnitude for aluminum and iron, but differ strongly in the case of copper. It is suggested that Jacobsen's α1, for copper, represents the stronge... View full abstract»

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  • On the Transition from Superconducting to Normal Phase, Accounting for Latent Heat and Eddy Currents

    Publication Year: 1959, Page(s):132 - 139
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (449 KB)

    A rigorous solution is given for the superconducting transition of a semi-infinite slab held at a point below the critical temperature Tc when a constant magnetic field above the critical value Hoc is applied. The solution accounts for both the absorption of latent heat and the dissipation of eddy-current heat during the transition. A numerical example is calculated for the c... View full abstract»

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  • Geometric Effects in the Superconducting Transition of Thin Films

    Publication Year: 1959, Page(s):140 - 146
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (389 KB)

    A study is made of the effect of geometric factors and field orientation on the superconducting transition of bulk material whose dimensional ratios are comparable to those of thin evaporated films. An expression is derived for an effective demagnetizing coefficient in the direction of the applied field for an elliptic cylindrical superconductor, and it is shown that this deviates from 1 by quanti... View full abstract»

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  • Computation of Sin N, Cos N, and m√N Using an Electronic Computer

    Publication Year: 1959, Page(s):147 - 152
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (396 KB)

    Rational Padé approximations to Sin N in the interval 0 ≤ N ≤ 41π/256 and to Cos N in 0 ≤ N ≤ 87π/256 allow the computation of both functions in 0 ≤ N ≤ π/2 with the first ten correct significant digits in four multiplications and divisions only. If the infinite range 0 ≤ N ≤ ∞ is considered, one more multip... View full abstract»

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  • Microwave Resonance in Gadolinium-Iron Garnet Crystals

    Publication Year: 1959, Page(s):153 - 162
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (574 KB)

    Ferrimagnetic resonance has been observed in single crystals of gadolinium-iron garnet at 9479 and 23,725 mc. The resonance behavior is discussed in terms of a two-sublattice theory. The gadolinium g-factor is equal to 2.006 above −90°C and increases at lower temperatures. The gadolinium ions contribute to the anisotropy below −40°C. The assignment of separate damping c... View full abstract»

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  • On Codes for Checking Logical Operations

    Publication Year: 1959, Page(s):163 - 168
    Cited by:  Papers (21)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (432 KB)

    Two types of codes for checking logical operations digit by digit on two vectors of binary digits are studied. The first type attaches a check symbol to each vector of binary digits and requires that the check symbol for the logical function of two vectors can be determined from the check symbols of the two input vectors. The second type of coding is ordinary block coding into vectors of binary di... View full abstract»

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  • Extension of Moore-Shannon Model for Relay Circuits

    Publication Year: 1959, Page(s):169 - 186
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (780 KB)

    The Moore-Shannon model for switching circuits is extended to show how the number of redundant relays needed to improve reliability depends on the logical function of the entire circuit. The reliabilities of and, or, and exclusive-or relay circuits are studied as a function of the number of relays, the network topology, and the distribution of inputs. For the case of intermittent failures, a proce... View full abstract»

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  • Numerical Solution of Laplace's Equation, Given Cauchy Conditions

    Publication Year: 1959, Page(s):187 - 188
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (269 KB)

    Usually Laplace's equation ▽2ψ=0 (or Poisson's equation ▽2ψ=F) must be solved with conditions given all around the boundary of the region in question. Yet in such specific engineering problems as the design of electron guns,1, 2 solutions are sought in an open region with the Cauchy boundary condition.** With Cauchy conditions, Laplace's... View full abstract»

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  • A Cryogenic Oscillator

    Publication Year: 1959, Page(s):189 - 190
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (264 KB)

    Two superconducting oscillators have been reported in the patent literature. F. E. Steele* of the Northrup Aircraft Corporation developed an oscillator based on a superconducting tank circuit. The device is characterized by high stability and low-energy outputs. Another oscillator was developed by E. A. Ericsson† of Sweden. This device also uses a tuned circuit but it is somewhat... View full abstract»

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  • Noise Theory for Hot Electrons

    Publication Year: 1959, Page(s):191 - 193
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (306 KB)

    The subject of this note is the extension of the Nyquist theorem, which relates the electrical noise in a conductor in thermal equilibrium to the Ohmic conductivity,1,2 to the “hot electron” situation in which there is a steady electric field E strong enough to disturb the distribution of electrons among Bloch states and for which the steady current density J will not in g... View full abstract»

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  • Doubling the Efficiency of the Load-Sharing Matrix Switch

    Publication Year: 1959, Page(s):194 - 196
    Cited by:  Papers (6)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (293 KB)

    Constantine* describes a novel load-sharing matrix switch in which the input winding pattern allows the selection of a single core, while ideally all other cores have zero net excitation. These patterns realize 2n−1 outputs with 2n inputs, the inputs being grouped in 2n−1 complementary pairs View full abstract»

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  • Elementary Divisors of Normal Matrices

    Publication Year: 1959, Page(s): 197
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (198 KB)

    It is known from the transformation theory of matrices that normal matrices can be brought to thed iagonal form by means of a similarity transformation. On the other hand, any diagonal matrix possesses linear elementary divisors exclusively. Since elementary divisors are unaltered by similarity transformations, it follows that normal matrices have linear elementary divisors only. View full abstract»

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  • The Reduction of Two-Way Automata to One-Way Automata

    Publication Year: 1959, Page(s):198 - 200
    Cited by:  Papers (19)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (290 KB)

    Rabin has proved1,2 that two-way finite automata, which are allowed to move in both directions along their input tape, are equivalent to one-way automata as far as the classification of input tapes is concerned. Rabin's proof is rather complicated and consists in giving a method for the successive elimination of loops in the motion of the machine. The purposeo f this note is to give a s... View full abstract»

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  • IBM Technical Papers Published in Other Journals

    Publication Year: 1959, Page(s):201 - 204
    IEEE is not the copyright holder of this material | PDF file iconPDF (340 KB)
    Freely Available from IEEE
  • Recent IBM Patents

    Publication Year: 1959, Page(s):205 - 206
    IEEE is not the copyright holder of this material | PDF file iconPDF (157 KB)
    Freely Available from IEEE
  • Authors

    Publication Year: 1959, Page(s):207 - 208
    IEEE is not the copyright holder of this material | PDF file iconPDF (210 KB)
    Freely Available from IEEE

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IBM T. J. Watson Research Center