SC²S Colloquium - October 25, 2012

From Sccswiki
Jump to navigation Jump to search
Date: October 25, 2012
Room: 02.07.023
Time: 4:30 pm, s.t.

Tijana Kovacevic: Aspects of Hybrid Molecular-Continuum Simulations for Complex Liquids

To capture flow physics at the nanoscale, one requires molecular dynamics simulations. These computationally very intensive simulations can be used to study flows in nano- to micrometer-sized domains. For bigger domains, even massively parallel systems may not be sufficient any more. This problem can be resolved through coupling the molecular dynamics with continuum simulations such as Lattice Boltzmann methods. This thesis explores two major aspects that are common in existing hybrid schemes. The generalized Usher algorithm that takes into account both rotational and translational degrees of freedom of molecules was implemented and used to insert new particles into the computational domain. Besides, this work discusses various approaches to apply radial-distribution-function-based boundary forces to model open boundaries in the molecular system.

Frank Ehmann: Development of a Shared-Memory Task Scheduling Library for Dynamically Changing Workloads

In dynamic applications the work load is not always balanced.

To still solve such problems in parallel, task scheduling can be used. This way the capabilities of the system can be optimally exploited. Thus an existing library, Threading Building Blocks, is used to observe its behavior.

Based on the observation an own, task-scheduler is introduced. The goal of this scheduler is to be lightweight, thus simple and easy to understand. The lightweight implementation is also destined to minimize the overhead of the task scheduler. This way the efficiency can be maximized. Beside the structure of the task-scheduler, implementation details are explained.

In dynamischen Anwendung ist die Arbeitslast nicht immer ausgeglichen.

Um solche probleme effizient auf parallelen Systemen zu lösen kann Task Scheduling eingesetzt werden. Dadurch können die Fähigkeiten des Systems bestmöglich genutzt werden. Eine Bibliothek, die Task Scheduling einsetzt ist Intel Threading Building Blocks.

Basierend auf den Erkenntnissen von TBB wird ein eigener Task Scheduler vorgestellt. Der Scheduler soll leichtgewichtig und einfach sein, somit zum Verständnis beitragen. Durch die leichtgewichtige Implementierung soll auch der Overhead minimiert und die Effizienz des Schedulers maximiert werden. Neben dem Aufbau des Task Schedulers werden auch Implementierungsdetails besprochen.