182,914 research outputs found

    IGA-based Multi-Index Stochastic Collocation for random PDEs on arbitrary domains

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    This paper proposes an extension of the Multi-Index Stochastic Collocation (MISC) method for forward uncertainty quantification (UQ) problems in computational domains of shape other than a square or cube, by exploiting isogeometric analysis (IGA) techniques. Introducing IGA solvers to the MISC algorithm is very natural since they are tensor-based PDE solvers, which are precisely what is required by the MISC machinery. Moreover, the combination-technique formulation of MISC allows the straight-forward reuse of existing implementations of IGA solvers. We present numerical results to showcase the effectiveness of the proposed approach.Comment: version 3, version after revisio

    Misc. Pub. 92-1

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    I submit herewith the annual report of the Agricultural and Forestry Experiment Station, School of Agriculture and Land Resources Management, University of Alaska Fairbanks, for the period ending December 31, 1991. This is done in accordance with an act of the Congress, approved M arch 2, 1887, entitled "An act to establish Agricultural Experiment Stations, in connection with the Agricultural Colleges established in the several states under the provisions of an act approved July 2,1862, and under the acts supplementary thereto," and also of the act of the Alaska Territorial Legislature, approved March 12,1935, accepting the provisions of the act of Congress. James V. Drew, DirectorStatement of Purpose -- Drastic Retreat of Columbia Glacier Shows Natural Reforestation at Work -- Reindeer Range and Productivity Studied in Beringia Heritage International Park -- Radio Collars Aid Research into Reindeer Calf Mortality -- Moose Browse on Site of Mining Reclamation Study -- Developing Marketing Strategies for Alaska's Agricultural Entrepreneurs -- R.S. 2477— The Key to Access Across Federal Lands -- Plant, Animal and Soil Sciences -- Forest Sciences -- Resources Management -- Grants and Funds -- Financial Statement -- Publications -- Staf

    Chapman-Enskog expansion about nonequilibrium states: the sheared granular fluid

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    The Chapman-Enskog method of solution of kinetic equations, such as the Boltzmann equation, is based on an expansion in gradients of the deviations fo the hydrodynamic fields from a uniform reference state (e.g., local equilibrium). This paper presents an extension of the method so as to allow for expansions about \emph{arbitrary}, far-from equilibrium reference states. The primary result is a set of hydrodynamic equations for studying variations from the arbitrary reference state which, unlike the usual Navier-Stokes hydrodynamics, does not restrict the reference state in any way. The method is illustrated by application to a sheared granular gas which cannot be studied using the usual Navier-Stokes hydrodynamics.Comment: 23 pages, no figures. Submited to PRE Replaced to correct misc. errors Replaced to correct misc. errors, make notation more consistant, extend discussio

    Misc. Pub. 2003-3

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    Misc. Pub. 88-1

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    I submit herewith the annual report of the Agricultural and Forestry Experiment Station, School of Agriculture and Land Resources Management, University of Alaska Fairbanks, for the period ending December 31, 1987. This is done in accordance with an act of the Congress, approved March 2, 1887, entitled "An act to establish Agricultural Experiment Stations, in connection with the Agricultural Colleges established in the several states under the provisions of an act approved July 2,1862, and under the acts supplementary thereto," and also of the act of the Alaska Territorial Legislature, approved March 12,1935, accepting the provisions of the act of Congress. James V. Drew, DirectorStatement of Purpose -- Plant and Animal Sciences -- Forest Sciences -- Resources Management -- Publications -- Financial Statement -- Staf

    Slow Fetal Heart Rate before Miscarriage in the Early First Trimester Predicts Fetal Aneuploidy in Women with Recurrent Pregnancy Loss

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    Establishing whether miscarriages result from fetal aneuploidy or other factors is important for treating recurrent pregnancy loss. We examined the relationship between fetal heart rate (FHR) before miscarriage in the early first trimester and fetal karyotype, analyzing 223 pregnant women with recurrent pregnancy loss. Among the pregnancies, 110 resulted in live births regarded as normal karyotype (the Norm-group). The other 113 pregnancies ended in miscarriage, and we categorized them into groups based on fetal karyotype, determined by chorionic villus sampling: the Misc-NK (normal karyotype) group, n=35 euploid cases; the Misc-CA1 (chromosomal abnormality) group, n=18 cases of aneuploidy with trisomies 13/18/21, Turner’s syndrome, or Klinefelter’s syndrome; and the Misc-CA2 subgroup, n=60 cases of other aneuploidies excluding those in the Misc-CA1 group. We compared the groups’ regression line slopes and intercepts for FHR by an analysis of covariance. The FHRs of the Norm, Misc-NK and Misc-CA1 groups increased from 36 to 49 days after fertilization, but did not significantly differ across these groups. The Misc-CA2 group’s FHR did not increase and significantly differed from the other three groups (p<0.01). These results suggest that the absence of an increase in FHR in early pregnancy may indicate the presence of chromosomal abnormalities causing miscarriage
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