504 research outputs found

    Performance Measurement and Analysis of Large-Scale Parallel Applications on Leadership Computing Systems

    Get PDF

    Portable lattice QCD software for massively parallel processor systems

    Get PDF

    Documentation of the data analysis system for the gamma ray monitor aboard OSO-H

    Get PDF
    The programming system is presented which was developed to prepare the data from the gamma ray monitor on OSO-7 for scientific analysis. The detector, data, and objectives are described in detail. Programs presented include; FEEDER, PASS-1, CAL1, CAL2, PASS-3, Van Allen Belt Predict Program, Computation Center Plot Routine, and Response Function Programs

    Interactive computer graphics in multivariate statistical research

    Get PDF
    The value of interactive computing and of interactive computer graphics is discussed with particular reference to the study of statistical data. A system designed for interactive graphics for multivariate statistics is described, including a command language to be used as part of this system. The system is in two parts: administrative programs and statistical programs. Types of statistical problems suitable for interactive graphical analysis are given, with the multivariate techniques used in the solution of these problems: principal components, factor analysis, cluster analysis and discriminant analysis. Each form of analysis is described with an outline of the program which implements the technique, including interactive aspects and forms of graphical output provided. The latter part of this thesis covers the use of these programs. Principal components analysis is used for two sets of dataj a selection of results is shown and discussed. Results obtained from factor analysis of data collected for a psychological study are similarly given. For a fourth data set, initially a cluster analysis solution is found. The graphical presentation of results led to the identification of a set of variables which dominates this initial solution. The interactive procedure for identifying this and further sets of variables is described. Finally, results obtained from the initial cluster analysis solution are input to the program for discriminant analysis

    Earth observations division Earth resources data analysis capabilities

    Get PDF
    There are no author-identified significant results in this report

    Computation applications in archaeology

    Get PDF
    This thesis is a critical analysis of the use which has been made of the computer in archaeology up to the year 1972. The main chapters cover the applications in archaeology of Statistics, Information Retrieval, Graphics, Pottery Classification and Survey Reduction. A large body of Miscellaneous Applications, including Pollen Analysis, are also examined. The majority of computer applications have been in Statistics. These applications include Numerical Taxonomy, Matrix Manipulation and Seriation, the generation of hypotheses and models, MUltidimensional Scaling, Cumulative Percentage Graphs and Trend Surface Analysis. It is worthwhile to note that for small sets of data several manual methods give comparable results to complex computer analyses and at far less cost. Computer Information Retrieval is examined in the light of its use for large bodies of specialist archaeological information, for museum cataloguing, and for the compilation of a site excavation record using a remote terminal. The use of Computer Graphics in the production of archaeological maps, plans and diagrams is examined. Facilities include the production of dot-density plots, distribution maps, histograms, piecharts, pottery diagrams, site block diagrams with 3D rotation and perspective, sections, pit outlines and projectile point classification by Fourier analysis. The use of the d-Mac Pencil Follower in the objective classification of pottery is described, followed by computer analysis of the resultant multivariate data. The use of the computer in the routine reduction of geophysical observations taken on archaeological sites is described. Complex filtering procedures for the removal of background effects and the enhancement of the archaeological anomalies are examined. Since other workers have concentrated on the applications of statistics in archaeology~ this thesis explores the relatively neglected fields of Graphics and Pottery Classification. Evidence is presented that significant advances have been made in the classification of pottery vessels and projectile points~ and in the graphical output of results. A number of new programs have been developed; these include software which may be operated from a remote terminal at an archaeological site. The P L U T A R C H System (Program Library Useful To ARCHaeologists) is described. This is a control program which uses interactive graphics and overlays to combine all the computer facilities available to the archaeologist. The individual graphics, statistics, instrument survey plotting and information retrieval techniques when combined in this way can communicate via global storage, and become even more powerful

    Quarterly literature review of the remote sensing of natural resources

    Get PDF
    The Technology Application Center reviewed abstracted literature sources, and selected document data and data gathering techniques which were performed or obtained remotely from space, aircraft or groundbased stations. All of the documentation was related to remote sensing sensors or the remote sensing of the natural resources. Sensors were primarily those operating within the 10 to the minus 8 power to 1 meter wavelength band. Included are NASA Tech Briefs, ARAC Industrial Applications Reports, U.S. Navy Technical Reports, U.S. Patent reports, and other technical articles and reports

    Analysis of some algorithms for use on paged virtual memory computers

    Get PDF
    PhD ThesisHandling a single page fault involves execution of thousands of instructions, drum rotational delay and is usually so expensive that if it can be avoided, almost any other cost can be tolerated. Optimizing operating system performance is usually the main concern of computer seientists who deal with paged memories. However, redesigning the algorithm used by a problem program can often result in a very significant reduction in paging, and hence in program execution time. The redesigned algorithm frequently does not satisfy the more conventional efficiency criteria. A sorting algorithm, Hash Coding and other search algorithms are considered. Analytic and simulation studies are presented, and aome modifications are proposed to reduce the number of page faults produced by data set references. Analysis is in terms of three of the most commonly used page replacement algorithms i.e. least recently used, first in first out, and random selection. The modifications are for the most part relatively minor and in some cases have appeared elsewhere in the context of searching on external storage media. The important aspects are the dramatic performance improvements which are possible, and the fact that classical internal algorithms are inappropriate for use in a paged virtual memory system.The Science Research Council: The University of Newcastle Upon Tyne: International Business Machines (United Kingdom) Limited.
    corecore