19 research outputs found

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    Software for Exascale Computing - SPPEXA 2016-2019

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    This open access book summarizes the research done and results obtained in the second funding phase of the Priority Program 1648 "Software for Exascale Computing" (SPPEXA) of the German Research Foundation (DFG) presented at the SPPEXA Symposium in Dresden during October 21-23, 2019. In that respect, it both represents a continuation of Vol. 113 in Springer’s series Lecture Notes in Computational Science and Engineering, the corresponding report of SPPEXA’s first funding phase, and provides an overview of SPPEXA’s contributions towards exascale computing in today's sumpercomputer technology. The individual chapters address one or more of the research directions (1) computational algorithms, (2) system software, (3) application software, (4) data management and exploration, (5) programming, and (6) software tools. The book has an interdisciplinary appeal: scholars from computational sub-fields in computer science, mathematics, physics, or engineering will find it of particular interest

    Electromagnetic muscle actuators

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 181-194).Actuator performance represents a key constraint on the capability of many engineered devices. Performance of these devices is often exceeded by their muscle-powered natural counterparts, inspiring the development of new, "active material" actuators. This thesis reconsiders a traditional actuator, the linear permanent magnet motor, as a form of active material actuator, and presents new, unified scaling and magnetic field models for its performance. This active material motor model predicts that motors composed of large numbers of very small, actively-cooled repeat units, similar to the architecture of biological muscles, can provide greatly enhanced force density over extant designs. Our model is constructed by considering the motor winding as an active material, with its performance limited by the diffusion of waste heat. This allows a quantitative scaling model for the motor constant and force-to-mass ratio to be built for the case of a winding immersed in a homogeneous magnetic field. This model is then modified with a small set of dimensionless parameters to describe the performance penalties imposed by the use of practical sources of magnetic field, specifically periodic arrays of permanent magnets. We explain how to calculate these parameters for a variety of different types of magnet arrays using analytical magnetic field and heat transfer models, and present a new field model for tubular linear motors having improved numerical stability and accuracy. We illustrate the use of our modeling approach with two design case studies, a motor for flapping-wing flying and an actuator for high-performance controllable needle-free jet injection. We then validate our predictions by building and testing a novel water-cooled motor using a tubular double-sided Halbach array of magnets, with a mass of 185 g, a stroke of 16 mm, and a magnetic repeat length of 14.5 mm. This motor generates a continuous force density of 140 N/kg, and has a motor constant of nearly 6 N/[square root]W, both higher than any previously reported motor in this size class.by Bryan Paul Ruddy.Ph.D

    Bibliography of Lewis Research Center technical publications announced in 1992

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    This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1992. All the publications were announced in the 1992 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

    Bibliography of Lewis Research Center technical publications announced in 1993

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    This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1993. All the publications were announced in the 1993 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

    MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications

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    Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described

    Generalized averaged Gaussian quadrature and applications

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    A simple numerical method for constructing the optimal generalized averaged Gaussian quadrature formulas will be presented. These formulas exist in many cases in which real positive GaussKronrod formulas do not exist, and can be used as an adequate alternative in order to estimate the error of a Gaussian rule. We also investigate the conditions under which the optimal averaged Gaussian quadrature formulas and their truncated variants are internal
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