A Gentle Introduction to Scientific Workflow Languages and Systems

Scientific workflows are an approach to implement automated, scalable, portable, and reproducible data analyses and in-silico experiments with low development costs.

Development Costs

What sets this approach apart from other distributed computing paradigms is its focus on the composition of programs. As a bioinformatics example, the output of a program that aligns reads to a reference genome is often processed by another program that analyzes genomic variants. Each of the programs is assumed to be readily available and is treated as a black box.

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Randomized Scheduling Paper Accepted at WORKS

Last week, my paper on randomized task graph scheduling was accepted at the Workshop on Workflows in Support of Large-Scale Science collocated with the SC18 in Dallas.

My idea behind this paper was to improve on the extremely good performance of the HEFT [1] scheduler I had observed in various experiments. My attack on the problem was to allocate a larger time budget to allow exploring variations of HEFT’s usually already good schedules.

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Conditional Recurrence Time

During my Master’s Thesis (pdf), I experimented with quantifications of Recurrence Plots. One of my ideas, which seems promising but is still immature, is the Conditional Recurrence Time (CRT) plot. It counts the lengths of pairs of white lines in a Recurrence Plot to characterize unstable periodic orbits (UPOs). This results in compact representations and new Recurrence Quantification Analysis (RQA) measures that allow classification of system dynamics.

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Clustering of Recurrence Plots

This article covers experiences from combining clustering algorithms with Recurrence Analysis. The results originate from my Master’s Thesis, which was supervised by Prof. Leser at Humboldt-Universität zu Berlin, the German Research Centre for Geosciences and the Potsdam Institute for Climate Impact Research. This might be interesting for physicists and people working with nonlinear phenomena and time series ensembles. If you are interested in ideas, data, or software, I’d be happy to pass them on. For a brief introduction on Recurrence Plots, scroll to the end of the page, or refer to the excellent collection of materials at http://www.recurrence-plot.tk/.

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