1,288 research outputs found

    Development of a material processing plant for lunar soil

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    Currently there is considerable interest in developing in-situ materials processing plants for both the Moon and Mars. Two of the most important aspects of developing such a materials processing plant is the overall system design and the integration of the different technologies into a reliable, lightweight, and cost-effective unit. The concept of an autonomous materials processing plant that is capable of producing useful substances from lunar regolith was developed. In order for such a materials processing plant to be considered as a viable option, it must be totally self-contained, able to operate autonomously, cost effective, light weight, and fault tolerant. In order to assess the impact of different technologies on the overall systems design and integration, a one-half scale model was constructed that is capable of scooping up (or digging) lunar soil, transferring the soil to a solar furnace, heating the soil in the furnace to liberate the gasses, and transferring the spent soil to a 'tile' processing center. All aspects of the control system are handled by a 386 class PC via D/A, A/D, and DSP (Digital Signal Processor) control cards

    XLOOPS -- A Program Package calculating One- and Two-Loop Feynman Diagrams

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    The aim of XLOOPS is to calculate one-particle irreducible Feynman diagrams with one or two closed loops for arbitrary processes in the Standard model of particles and related theories. Up to now this aim is realized for all one-loop diagrams with at most three external lines and for two-loop diagrams with two external lines.Comment: 84 pages, Postscript, program package and this manual also available at http://wwwthep.physik.uni-mainz.de/~xloops/, minor changes and bug fixes are included no

    Robo-line storage: Low latency, high capacity storage systems over geographically distributed networks

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    Rapid advances in high performance computing are making possible more complete and accurate computer-based modeling of complex physical phenomena, such as weather front interactions, dynamics of chemical reactions, numerical aerodynamic analysis of airframes, and ocean-land-atmosphere interactions. Many of these 'grand challenge' applications are as demanding of the underlying storage system, in terms of their capacity and bandwidth requirements, as they are on the computational power of the processor. A global view of the Earth's ocean chlorophyll and land vegetation requires over 2 terabytes of raw satellite image data. In this paper, we describe our planned research program in high capacity, high bandwidth storage systems. The project has four overall goals. First, we will examine new methods for high capacity storage systems, made possible by low cost, small form factor magnetic and optical tape systems. Second, access to the storage system will be low latency and high bandwidth. To achieve this, we must interleave data transfer at all levels of the storage system, including devices, controllers, servers, and communications links. Latency will be reduced by extensive caching throughout the storage hierarchy. Third, we will provide effective management of a storage hierarchy, extending the techniques already developed for the Log Structured File System. Finally, we will construct a protototype high capacity file server, suitable for use on the National Research and Education Network (NREN). Such research must be a Cornerstone of any coherent program in high performance computing and communications

    Experimental investigation of effects of jet decay rate on jet-induced pressures on a flat plate: Tabulated data

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    Tabular data are presented for an experimental study of the effects of jet decay rate on the jet-induced pressure distribution on a flat plate for a single jet issuing at right angle to the flat plate into a uniform crossflow. The data are presented in four sections: (1) presents the static nozzle calibration data; (2) lists the plate surface static pressure data and integrated loads; (3) lists the jet centerline trajectory data; and (4) lists the centerline dynamic pressure data

    On data skewness, stragglers, and MapReduce progress indicators

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    We tackle the problem of predicting the performance of MapReduce applications, designing accurate progress indicators that keep programmers informed on the percentage of completed computation time during the execution of a job. Through extensive experiments, we show that state-of-the-art progress indicators (including the one provided by Hadoop) can be seriously harmed by data skewness, load unbalancing, and straggling tasks. This is mainly due to their implicit assumption that the running time depends linearly on the input size. We thus design a novel profile-guided progress indicator, called NearestFit, that operates without the linear hypothesis assumption and exploits a careful combination of nearest neighbor regression and statistical curve fitting techniques. Our theoretical progress model requires fine-grained profile data, that can be very difficult to manage in practice. To overcome this issue, we resort to computing accurate approximations for some of the quantities used in our model through space- and time-efficient data streaming algorithms. We implemented NearestFit on top of Hadoop 2.6.0. An extensive empirical assessment over the Amazon EC2 platform on a variety of real-world benchmarks shows that NearestFit is practical w.r.t. space and time overheads and that its accuracy is generally very good, even in scenarios where competitors incur non-negligible errors and wide prediction fluctuations. Overall, NearestFit significantly improves the current state-of-art on progress analysis for MapReduce

    Optics: general-purpose scintillator light response simulation code

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    We present the program optics that simulates the light response of an arbitrarily shaped scintillation particle detector. Predicted light responses of pure CsI polygonal detectors, plastic scintillator staves, cylindrical plastic target scintillators and a Plexiglas light-distribution plate are illustrated. We demonstrate how different bulk and surface optical properties of a scintillator lead to specific volume and temporal light collection probability distributions. High-statistics optics simulations are calibrated against the detector responses measured in a custom-made cosmic muon tomography apparatus. The presented code can also be used to track particles intersecting complex geometrical objects.Comment: RevTeX LaTeX, 37 pages in e-print format, 12 Postscript Figures and 1 Table, also available at http://pibeta.phys.virginia.edu/public_html/preprints/optics.p

    An introduction to scripting in Ruby for biologists

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    <p>Abstract</p> <p>The Ruby programming language has a lot to offer to any scientist with electronic data to process. Not only is the initial learning curve very shallow, but its reflection and meta-programming capabilities allow for the rapid creation of relatively complex applications while still keeping the code short and readable. This paper provides a gentle introduction to this scripting language for researchers without formal informatics training such as many wet-lab scientists. We hope this will provide such researchers an idea of how powerful a tool Ruby can be for their data management tasks and encourage them to learn more about it.</p

    Some Notes on the Construction of Christos Ho Pantepoptes (Eski Imaret Camii) in Istanbul

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    Μη διαθέσιμη περίληψηno abstrac

    Binbirkilise Revisited: The 1887 Photographs of John Henry Haynes

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    Η τοποθεσία των πρώιμων βυζαντινών χρόνων του Binbirkilise (οι χίλιες και μία εκκλησίες), κοντά στην επαρχία Καραμάν στη Λυκαονία, είναι περισσότερο γνωστή από την τεκμηρίωση του 1907 του Sir William M. Ramsay και της Gertrude Bell. Άγνωστη σε αυτούς, ωστόσο, ήταν η επίσκεψη το 1887 του Αμερικανού αρχαιολόγου John Henry Haynes, ο οποίος φωτογράφισε τους ναούς 8, 10, 13, 32 και 39. Εξαιτίας σοβαρών φθορών στα κτήρια μεταξύ του 1887 και του 1907, οι φωτογραφίες του Haynes παρέχουν σημαντικές λεπτομέρειες των κτηρίων, οι οποίες δεν ήταν γνωστές στους μεταγενέστερους ερευνητές.The early Byzantine site of Binbirkilise (the Thousand and One Churches) near Karaman in Lycaonia is best known today from the 1907 documentation by Sir William M. Ramsay and Gertrude Bell. Unknown to them, however, was the visit in 1887 by the American archaeologist John Henry Haynes, who took photographs of Churches 8, 10, 13, 32, and 39. Because of severe damage to the buildings between 1887 and 1907, Haynes’s photographs provide important details of the buildings not available to later scholars
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