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IBM Journal of Research and Development

Issue 6 • Nov. 1981

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Displaying Results 1 - 15 of 15
  • Design of Experiments in Computer Performance Evaluation

    Publication Year: 1981, Page(s):848 - 859
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1008 KB)

    Techniques of statistical design of experiments have been successfully employed for many decades in a variety of applications in industry, agriculture, medicine, psychology, and other physical and social sciences. Their aim is to provide scientific and efficient means of studying the effects, on one or more variables of interest, of varying multiple controllable factors in an experiment. These tec... View full abstract»

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  • Adaptive Spectral Methods for Simulation Output Analysis

    Publication Year: 1981, Page(s):860 - 876
    Cited by:  Papers (10)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1053 KB)

    This paper addresses two central problems in simulation methodology: the generation of confidence intervals for the steady state means of the output sequences and the sequential use of these confidence intervals to control the run length. The variance of the sample mean of a covariance stationary process is given approximately by p(0)/N, where p(f) is the spectral density at frequency f and N is t... View full abstract»

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  • The Software-Cache Connection

    Publication Year: 1981, Page(s):877 - 893
    Cited by:  Papers (7)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1208 KB)

    This paper describes an adaptation of standard Fourier analysis techniques to the study of software-cache interactions. The cache is viewed as a “black box” Boolean signal generator, where “ones” correspond to cache misses and “zeros” correspond to cache hits. The spectrum of this time sequence is used to study the dynamic characteristics of complex system... View full abstract»

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  • Approximate Solution of Queueing Networks with Simultaneous Resource Possession

    Publication Year: 1981, Page(s):894 - 903
    Cited by:  Papers (7)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (799 KB)

    Queueing networks are important as performance models of computer and communication systems because the performance of these systems is usually principally affected by contention for resources. Exact numerical solution of a queueing network is usually only feasible if the network has a product form solution in the sense of Jackson. An important network characteristic which apparently precludes a p... View full abstract»

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  • Collision-Free Local Area Bus Network Performance Analysis

    Publication Year: 1981, Page(s):904 - 914
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (931 KB)

    This paper deals with port access control for local area computer communication bus networks. Emphasizing properties of the algorithms and delay-throughput performance, we focus on two collision-free access control schemes recently proposed by Eswaran, Hamacher, and Shedler. We also provide a comparison of these schemes to other available bus access techniques. The performance analysis is based on... View full abstract»

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  • Delay Analysis of a Two-Queue, Nonuniform Message Channel

    Publication Year: 1981, Page(s):915 - 929
    Cited by:  Patents (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1017 KB)

    A Message Channel is defined as a tandem connection of single server queues in which the successive service times experienced by any particular customer are scaled versions of the same random variable, and thus it serves as a model for sparsely connected store-and-forward data communications networks (or network segments) where messages typically preserve their lengths as they traverse the system.... View full abstract»

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  • Message Reassembly Times in a Packet Network

    Publication Year: 1981, Page(s):930 - 933
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (315 KB)

    This paper addresses the problem of computing the reassembly time of a multipacket message. All packets from a single message are assumed to flow in sequence along the same physical path. The analysis includes the effects of contention between messages in the network on the delay time at each station along the path and its impact on message reassembly time. View full abstract»

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  • Fleshing Out Projections

    Publication Year: 1981, Page(s):934 - 954
    Cited by:  Papers (23)  |  Patents (16)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1636 KB)

    In an earlier paper, the authors presented an algorithm for finding all polyhedral solid objects with a given set of vertices and straight line edges (its wire frame). This paper extends the Wire Frame algorithm to find all solid polyhedral objects with a given set of two dimensional projections. These projections may contain depth information in the form of dashed and solid lines, may represent c... View full abstract»

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  • An Emulation System for Programmable Sensory Robots

    Publication Year: 1981, Page(s):955 - 962
    Cited by:  Papers (16)  |  Patents (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (656 KB)

    This paper describes EMULA, an experimental interactive system for the emulation of sensory robots. EMULA was constructed as a bridge between an existing language for driving actual robots and an existing geometric modeling system. The modeling system was extended to handle mechanisms, such as robots, and an emulation language was introduced to indicate certain specific physical effects, including... View full abstract»

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  • Impact of a Liquid Drop Against a Flat Surface

    Publication Year: 1981, Page(s):963 - 971
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (634 KB)

    Lagrangian methods are used with an assumed flow field and a truncated sphere model to analyze the dynamical process of a liquid drop impacting a flat, rigid surface. The resulting differential equation for drop height as a function of time during contact is solved numerically for several values of the three parameters: Weber number of the incoming drop, ratio of the surface tension in air to that... View full abstract»

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  • Recent Papers by IBM Authors

    Publication Year: 1981, Page(s):972 - 979
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (666 KB)

    Reprints of the papers listed here may usually be obtained by writing directly to the authors. The authors' IBM divisions or groups are identified as follows: CHQ is Corporate Headquarters; DPD, Data Processing Division; DPMG, Data Processing Marketing Group; DPPG, Data Processing Product Group; DSD, Data Systems Division; FED Field Engineering Division; FSD, Federal Systems Division; GBG, General... View full abstract»

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  • Recent IBM patents

    Publication Year: 1981, Page(s):980 - 983
    IEEE is not the copyright holder of this material | PDF file iconPDF (307 KB)
    Freely Available from IEEE
  • Authors

    Publication Year: 1981, Page(s):984 - 986
    IEEE is not the copyright holder of this material | PDF file iconPDF (303 KB)
    Freely Available from IEEE
  • Author Index for Papers in Volume 25

    Publication Year: 1981, Page(s):987 - 990
    IEEE is not the copyright holder of this material | PDF file iconPDF (260 KB)
    Freely Available from IEEE
  • Subject Index for Papers in Volume 25

    Publication Year: 1981, Page(s):991 - 994
    IEEE is not the copyright holder of this material | PDF file iconPDF (263 KB)
    Freely Available from IEEE

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