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Full-Text Articles in Physics
Modelling Parallel Overhead From Simple Run-Time Records, Siegfried Höfinger, Ernst Haunschmid
Modelling Parallel Overhead From Simple Run-Time Records, Siegfried Höfinger, Ernst Haunschmid
Michigan Tech Publications
A number of scientific applications run on current HPC systems would benefit from an approximate assessment of parallel overhead. In many instances a quick and simple method to obtain a general overview on the subject is regarded useful auxiliary information by the routine HPC user. Here we present such a method using just execution times for increasing numbers of parallel processing cores. We start out with several common scientific applications and measure the fraction of time spent in MPI communication. Forming the ratio of MPI time to overall execution time we obtain a smooth curve that can be parameterized by …
Effect Of Thermodenuding On The Structure Of Nascent Flame Soot Aggregates, Janarjan Bhandari, Swarup China, Timothy Onasch, Lindsay Wolff, Andrew Lambe, Paul Davidovits, Claudio Mazzoleni, Et Al.
Effect Of Thermodenuding On The Structure Of Nascent Flame Soot Aggregates, Janarjan Bhandari, Swarup China, Timothy Onasch, Lindsay Wolff, Andrew Lambe, Paul Davidovits, Claudio Mazzoleni, Et Al.
Michigan Tech Publications
The optical properties (absorption and scattering) of soot particles depend on soot size and index of refraction, but also on the soot complex morphology and the internal mixing with materials that can condense on a freshly emitted (nascent) soot particle and coat it. This coating can affect the soot optical properties by refracting light, or by changing the soot aggregate structure. A common approach to studying the effect of coating on soot optical properties is to measure the absorption and scattering coefficients in ambient air, and then measure them again after removing the coating using a thermodenuder. In this approach, …