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IBM Journal of Research and Development

Issue 2 • March 1979

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Displaying Results 1 - 16 of 16
  • HeNe Parallel Plate Laser Development

    Publication Year: 1979, Page(s):108 - 118
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (845 KB)

    A parallel plate format is used for fabricating “hard” sealed HeNe lasers. The new packaging geometry and construction process are suitable for large scale manufacturing. Cut plate, molded plate, and folded beam lasers have been built and tested. Several changes from conventional lasers, such as evaporated film cathode and anode, square cross section bore, glass sealed Brewster windo... View full abstract»

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  • Cathodes for HeNe Lasers

    Publication Year: 1979, Page(s):119 - 127
    Cited by:  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (493 KB)

    Vapor deposited aluminum cathodes for parallel plate HeNe lasers have been used with considerable success. It is shown that the aluminum cold cathode is improved by the addition of copper and that other alloying elements of bulk Al 2024 do not contribute to cathode performance. The plasma oxidation process of Hochuli improves cathode performance by cleaning the surface and optimizing the oxide fil... View full abstract»

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  • Nondestructive Analysis for HeNe Lasers

    Publication Year: 1979, Page(s):128 - 131
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (330 KB)

    The methods used to measure the gas properties in sealed helium-neon lasers are described. Such parameters as total gas pressure, minor constituent concentration (i.e., He/Ne ratio), and gas purity can be measured using spectral emission methods. How these parameters and measurement techniques relate to the electrical operating characteristics of the laser is described. View full abstract»

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  • Polarization Problems of Parallel Plate Lasers

    Publication Year: 1979, Page(s):132 - 139
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (569 KB)

    Parallel plate laser technology requires that the plasma envelope and particularly the Brewster windows be “hard sealed.” The first part of this study reports the effects of misalignments of the Brewster windows on laser performance. This turned out not to be a serious problem. In the second part the increase in the birefringence of the Brewster windows resulting from the hard seal t... View full abstract»

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  • Reduction of Storage Fragmentation On Direct Access Devices

    Publication Year: 1979, Page(s):140 - 148
    Cited by:  Papers (3)  |  Patents (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (656 KB)

    A technique is described for partially reorganizing the contents of disk storage so as to reduce the level of fragmentation. The method entails choosing that fraction of the contents which is estimated to have the greatest impact on the free space distribution, followed by the relocation of these data to more favorable locations, subject to the system integrity requirements. View full abstract»

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  • Arithmetic Coding

    Publication Year: 1979, Page(s):149 - 162
    Cited by:  Papers (176)  |  Patents (12)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (963 KB)

    The earlier introduced arithmetic coding idea has been generalized to a very broad and flexible coding technique which includes virtually all known variable rate noiseless coding techniques as special cases. An outstanding feature of this technique is that alphabet extensions are not required. A complete decodability analysis is given. The relationship of arithmetic coding to other known nonblock ... View full abstract»

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  • High-Speed Programmable Logic Array Adders

    Publication Year: 1979, Page(s):163 - 178
    Cited by:  Papers (6)  |  Patents (23)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (909 KB)

    Programmable Logic Array (PLA) adders are described which perform an addition in one cycle with a single pass through a PLA and require a reasonable number of product terms for an 8-, 16-, or even a 32-bit adder. The PLA features two- bit input decoders feeding an AND array followed by an OR array whose outputs are pairwise EXCLUSIVE-ORed. Carry-look-ahead adder equations, adapted to the PLA to re... View full abstract»

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  • Thermal Stress in Bonded Joints

    Publication Year: 1979, Page(s):179 - 188
    Cited by:  Papers (66)  |  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (591 KB)

    This paper considers the stress distributions in bonded materials induced by differential expansion or contraction of these materials. The analytical approach is similar to the lap joint theories attributed to Volkersen and expanded by Goland and Reissner. Several simple and typical analytical models are presented to bring out the relative importance of different geometrical and material parameter... View full abstract»

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  • Implications of a Selective Acknowledgment Scheme on Satellite Performance

    Publication Year: 1979, Page(s):189 - 196
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (550 KB)

    Data link response time is becoming more of a concern today with the onset of satellite transmissions of computer data. The long propagation delay inherent to satellite communications may lead to a degradation in data link response time as compared to the same transmission over purely terrestrial links. Furthermore, data link errors need be considered in any such study of response time of satellit... View full abstract»

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  • Study of Head-Tape Interaction in High Speed Rotating Head Recording

    Publication Year: 1979, Page(s):197 - 205
    Cited by:  Papers (7)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (610 KB)

    The steady state tape dynamics resulting from the interaction of a high speed rotating head and a flexible recording tape are formulated within the framework of linear shell theory. Tape displacements in the area above the head are coupled with the solution to the Reynolds equation in order to calculate the film thickness (flying height) between head and tape. Simulated results for spherical heads... View full abstract»

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  • Rapid and Precise Method for Analysis of Energy Dispersive X-Ray Spectra

    Publication Year: 1979, Page(s):206 - 213
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (508 KB)

    A new, precise, and rapid method for the analysis of energy dispersive x-ray spectra generated by electron beam or x-ray excitation is presented. It includes the use of Gaussian profiles and a polynomial of 1/E (where E is the x-ray energy) to represent the observed x-ray characteristic lines and background, automatic sectioning of the entire spectrum, and a figure of merit to estimate goodness of... View full abstract»

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  • Contrast Attenuation Factors for Remote Sensing

    Publication Year: 1979, Page(s):214 - 224
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (738 KB)

    Attenuation factors for the contrast of objects lying on the earth's surface and observed through five different atmospheric models are calculated as a function of the wavelength (0.31-0.9935 µm), solar zenith angle, ground reflectivity, and the nadir and azimuth angles of view. The first model is free of aerosols and absorbing gases. Absorption by average amounts of oxygen, ozone, and wate... View full abstract»

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  • On the Application of Coding Theory to Hashing

    Publication Year: 1979, Page(s):225 - 226
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (167 KB)

    Quick proofs are given for the characterization (due to Schay, Raver, Hanan, and Palermo) of the collision distance of a linear hashing function and for a dual notion (called the restriction distance), which relates to the accessibility of addresses by sets of keys and the uniform distribution of sets of keys over addresses. View full abstract»

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  • Recent papers by IBM authors

    Publication Year: 1979, Page(s):227 - 232
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (500 KB)

    Reprints of the papers listed here may usually be obtained by writing directly to the authors. The authors' IBM divisions are identified as follows: CHQ is Corporate Headquarters; DPD, Data Processing Division; DSD, Data Systems Division; FED, Field Engineering Division; FSD, Federal Systems Division; GPD, General Products Division; GSD, General Systems Division; OPD, Ofice Products Division; RES,... View full abstract»

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  • Recent IBM patents

    Publication Year: 1979, Page(s):233 - 234
    IEEE is not the copyright holder of this material | PDF file iconPDF (154 KB)
    Freely Available from IEEE
  • Authors

    Publication Year: 1979, Page(s):235 - 238
    IEEE is not the copyright holder of this material | PDF file iconPDF (347 KB)
    Freely Available from IEEE

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IBM T. J. Watson Research Center