122 research outputs found
Parallel job support in the Spanish NGI
Trabajo presentado a la 4th Iberian Grid Infrastructure Conference celebrada en Braga (Portugal) del 24 al 27 de mayo de 2010.-- Los archivos adjuntos corresponden al texto completo de la comunicación de congreso y a la presentación.Execution of parallel applications on a Grid environment is a challenging problem that requires the cooperation of several middleware tools and services. Although current grid middleware stacks have a basic level of support for such applications, this support is very limited. Users face a very heterogeneous environment lacking any standards for managing their jobs. We present a complete framework for the execution of parallel applications in grid environments that hides the underlying complexity with a simple interface to run the applications. The framework is composed of a unified interface layer for starting parallel applications and a grid scheduler that provides transparent and reliable support for such types of applications. The framework is focused on MPI applications, but extensible to other types of parallel applications.The authors acknoledge support of the European Comission FP7 program, under contract number 211804 through the project EUFORIA (http://www.euforia-project.eu)Peer reviewe
Support to MPI Applications on the Grid
The current middleware stacks provide varying support for the Message Passing Interface (MPI) programming paradigm. Users face a complex and heterogeneous environment where too many low level details have to be specified to execute even the simplest parallel jobs. MPI-Start is a tool that provides an interoperable MPI execution framework across the different middleware implementations to abstract the user interfaces from the underlying middleware and to allow users to execute parallel applications in a uniform way, thus bridging the gap between HPC and HTC. In this work we present the latest developments in MPI-Start and how it can be integrated in the different middleware stacks available as part of EMI, providing a unified user experience for MPI jobs
Characterization of nanoparticles generated in reacting flows
In this thesis, particle formation in reacting flows is investigated experimentally. Two separate systems are considered. First, silica particle synthesis is characterized in a cold, turbulent jet doped with trace amounts of silane gas that issues into a vitiated co-flow. Additionally, soot formation is characterized in a laminar ethylene diffusion flame.
Laser diagnostic techniques are the cornerstone of this work and make it possible to perform measurements with minimal disruption to the system. In both scenarios, elastic light scattering (ELS) and OH-PLIF are employed to obtain experimental signals that contain information about temperature, particle formation, OH concentration and other physical quantities. Additionally, line-of-sight extinction is used in the soot-forming system to recover integrated soot volume fraction profiles and multi-angle light scattering (MALS) is demonstrated on the silica-forming system to obtain in-situ information about particle size.
Laser-based datasets are supplemented by probe measurements, including temperature profiles measured using radiation-corrected thermocouples and TEM analysis of particle samples obtained by location-specific thermophoretic sampling.
Fully-defined numerical models, available in both scenarios, are validated following an unconventional approach based on the comparison of “predicted signals” with experimentally-obtained signals, as a means to avoid introducing additional assumptions.
Satisfactory agreement is found, even though some discrepancies remain concerning silica particle formation, which are likely related to uncertainties in precursor chemistry and nucleation. Nevertheless, this is one of a few joint numerical and experimental studies that address particle formation under turbulent conditions. Regarding soot formation in laminar flames, a consistent underprediction of soot formation on the centreline is identified, which is believed to be a limitation of the acetylene-based model.
In summary, this work uses optical diagnostic techniques to generate extensive datasets of particle-forming reacting jets, making a major contribution towards the validation of computational tools to predict particle formation in turbulent reacting flows as well as soot formation in laminar flames.Open Acces
Penerapan Pendekatan Keterampilan Proses Sains dalam Model Pembelajaran Guided Discovery untuk Meningkatkan Hasil Belajar IPA Fisika Pada Siswa Kelas VIIa SMPN 8 Mataram Tahun Ajaran 2015/2016
The purposes of this research is to improve learning outcomes of students at SMPN 8 Mataram. This is a classroom action research with two cycles. Each cycles include planning, implementation, observation, evaluation and reflection. Implementation of guided discovery learning model made 5 phases: introduction, orientation of students on the issue, conducting, presenting and evaluating results. In the first cycle, obtained an average student learning outcomes at 74.82, while in the second cycle of 81.75. Classical mastery learning in the first cycle of 64.7% and in the second cycle of 86%. Activities of students and teachers that are in the active category. Based on these results it can be concluded that the application of guided discovery learning models with science process skills approach is proven to increase physics learning outcomes of students at SMPN 8 Mataram
MPI Support on the Grid
Grids as infrastructures offer access to computing, storage and other resources in a transparent way. The user does not have to be aware where and how the job is being executed. Grid clusters in particular are an interesting target for running computation-intensive calculations. Running MPI-parallel applications on such clusters is a logical approach that is of interest to both computer scientists and to engineers. This paper gives an overview of the issues connected to running MPI applications on a heterogenous Grid consisting of different clusters located at different sites within the Int.EU.Grid project. The role of a workload management system (WMS) for such a scenario, as well as important modifications that need to be made to a WMS oriented towards sequential batch jobs for better support of MPI applications and tools are discussed. In order to facilitate the adoption of MPI-parallel applications on heterogeneous Grids, the application developer should be made aware of performance problems, as well as MPI-standard issues within its code. Therefore tools for these issues are also supported within Int.EU.Grid. Also, the special case of running MPI applications on different clusters simultaneously as a more Grid-oriented computational approach is described
Penerapan Pendekatan Keterampilan Proses Sains Dalam Model Pembelajaran Guided Discovery Untuk Meningkatkan Hasil Belajar IPA Fisika Pada Siswa Kelas VIIa SMPN 8 Mataram Tahun Ajaran 2015/2016
The purposes of this research is to improve learning outcomes of students at SMPN 8 Mataram. This is a classroom action research with two cycles. Each cycles include planning, implementation, observation, evaluation and reflection. Implementation of guided discovery learning model made 5 phases: introduction, orientation of students on the issue, conducting, presenting and evaluating results. In the first cycle, obtained an average student learning outcomes at 74.82, while in the second cycle of 81.75. Classical mastery learning in the first cycle of 64.7% and in the second cycle of 86%. Activities of students and teachers that are in the active category. Based on these results it can be concluded that the application of guided discovery learning models with science process skills approach is proven to increase physics learning outcomes of students at SMPN 8 Mataram
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