2,267 research outputs found
E-BioFlow: Different Perspectives on Scientific Workflows
We introduce a new type of workflow design system called\ud
e-BioFlow and illustrate it by means of a simple sequence alignment workflow. E-BioFlow, intended to model advanced scientific workflows, enables the user to model a workflow from three different but strongly coupled perspectives: the control flow perspective, the data flow perspective, and the resource perspective. All three perspectives are of\ud
equal importance, but workflow designers from different domains prefer different perspectives as entry points for their design, and a single workflow designer may prefer different perspectives in different stages of workflow design. Each perspective provides its own type of information, visualisation and support for validation. Combining these three perspectives in a single application provides a new and flexible way of modelling workflows
A High Throughput Workflow Environment for Cosmological Simulations
The next generation of wide-area sky surveys offer the power to place
extremely precise constraints on cosmological parameters and to test the source
of cosmic acceleration. These observational programs will employ multiple
techniques based on a variety of statistical signatures of galaxies and
large-scale structure. These techniques have sources of systematic error that
need to be understood at the percent-level in order to fully leverage the power
of next-generation catalogs. Simulations of large-scale structure provide the
means to characterize these uncertainties. We are using XSEDE resources to
produce multiple synthetic sky surveys of galaxies and large-scale structure in
support of science analysis for the Dark Energy Survey. In order to scale up
our production to the level of fifty 10^10-particle simulations, we are working
to embed production control within the Apache Airavata workflow environment. We
explain our methods and report how the workflow has reduced production time by
40% compared to manual management.Comment: 8 pages, 5 figures. V2 corrects an error in figure
Tasks, cognitive agents, and KB-DSS in workflow and process management
The purpose of this paper is to propose a nonparametric interest rate term structure model and investigate its implications on term structure dynamics and prices of interest rate derivative securities. The nonparametric spot interest rate process is estimated from the observed short-term interest rates following a robust estimation procedure and the market price of interest rate risk is estimated as implied from the historical term structure data. That is, instead of imposing a priori restrictions on the model, data are allowed to speak for themselves, and at the same time the model retains a parsimonious structure and the computational tractability. The model is implemented using historical Canadian interest rate term structure data. The parametric models with closed form solutions for bond and bond option prices, namely the Vasicek (1977) and CIR (1985) models, are also estimated for comparison purpose. The empirical results not only provide strong evidence that the traditional spot interest rate models and market prices of interest rate risk are severely misspecified but also suggest that different model specifications have significant impact on term structure dynamics and prices of interest rate derivative securities.
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