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Michela Taufer

Publications and source records attributed to Michela Taufer.

22 records · Page 2Linked to original sources

Applicability study of the PRIMAD model to LIGO gravitational wave search workflows

The PRIMAD model with its six components (i.e., Platform, Research Objective, Implementation, Methods, Actors, and Data), provides an abstract taxonomy to represent computational experiments and enforce reproducibility by design. In this paper, we assess the model applicability to a set of Laser Interferometer Gravitational-Wave Observatory (LIGO) workflows from literature sources (i.e., published papers). Our work outlines potentials and limits of the model in terms of its abstraction levels and application process.

cs.DC↗

Studying the Impact of Power Capping on MapReduce-based, Data-intensive Mini-applications on Intel KNL and KNM Architectures

In this poster, we quantitatively measure the impacts of data movement on performance in MapReduce-based applications when executed on HPC systems. We leverage the PAPI 'powercap' component to identify ideal conditions for execution of our applications in terms of (1) dataset characteristics (i.e., unique words); (2) HPC system (i.e., KNL and KNM); and (3) implementation of the MapReduce programming model (i.e., with or without combiner optimizations). Results confirm the high energy and runtime costs of data movement, and the benefits of the combiner optimization on these costs.

cs.DC↗

In-Situ Data Analysis of Protein Folding Trajectories

The transition from petascale to exascale computers is characterized by substantial changes in the computer architectures and technologies. The research community relying on computational simulations is being forced to revisit the algorithms for data generation and analysis due to various concerns, such as higher degrees of concurrency, deeper memory hierarchies, substantial I/O and communication constraints. Simulations today typically save all data to analyze later. Simulations at the exascale will require us to analyze data as it is generated and save only what is really needed for analysis, which must be performed predominately in-situ, i.e., executed sufficiently fast locally, limiting memory and disk usage, and avoiding the need to move large data across nodes. In this paper, we present a distributed method that enables in-situ data analysis for large protein folding trajectory datasets. Traditional trajectory analysis methods currently follow a centralized approach that moves the trajectory datasets to a centralized node and processes the data only after simulations have been completed. Our method, on the other hand, captures conformational information in-situ using local data only while reducing the storage space needed for the part of the trajectory under consideration. This method processes the input trajectory data in one pass, breaks from the centralized approach of traditional analysis, avoids the movement of trajectory data, and still builds the global knowledge on the formation of individual $α$-helices or $β$-strands as trajectory frames are generated.

cs.CE↗

Hierarchical fractional-step approximations and parallel kinetic Monte Carlo algorithms

We present a mathematical framework for constructing and analyzing parallel algorithms for lattice Kinetic Monte Carlo (KMC) simulations. The resulting algorithms have the capacity to simulate a wide range of spatio-temporal scales in spatially distributed, non-equilibrium physiochemical processes with complex chemistry and transport micro-mechanisms. The algorithms can be tailored to specific hierarchical parallel architectures such as multi-core processors or clusters of Graphical Processing Units (GPUs). The proposed parallel algorithms are controlled-error approximations of kinetic Monte Carlo algorithms, departing from the predominant paradigm of creating parallel KMC algorithms with exactly the same master equation as the serial one. Our methodology relies on a spatial decomposition of the Markov operator underlying the KMC algorithm into a hierarchy of operators corresponding to the processors' structure in the parallel architecture. Based on this operator decomposition, we formulate Fractional Step Approximation schemes by employing the Trotter Theorem and its random variants; these schemes, (a) determine the communication schedule} between processors, and (b) are run independently on each processor through a serial KMC simulation, called a kernel, on each fractional step time-window. Furthermore, the proposed mathematical framework allows us to rigorously justify the numerical and statistical consistency of the proposed algorithms, showing the convergence of our approximating schemes to the original serial KMC. The approach also provides a systematic evaluation of different processor communicating schedules.

math.NA↗