| 1. |
- Feig, Michael, et al.
(författare)
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Large Scale Data Repository : Design of a Molecular Dynamics Trajectory Database
- 1999
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Ingår i: Future generations computer systems. - : Elsevier. - 0167-739X .- 1872-7115. ; 16:1, s. 101-110
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Tidskriftsartikel (refereegranskat)abstract
- The design of a molecular dynamics trajectory database is presented as an example of the organization of large-scale dynamic distributed repositories for scientific data. Large scientific datasets are usually interpreted through reduced data calculated by analysis functions. This allows a database architecture in which the analyzed datasets, that are kept in addition to the raw datasets, are transferred to a database user. A flexible user interface with a well defined Application Program Interface (API) allows for a wide array of analysis functions and the incorporation of user defined functions is a critical part of the database design. An analysis function is executed only when the requested analysis result is not available from an earlier request. A prototype implementation used to gain initial practical experiences with performance and scalability is presented.
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| 2. |
- Fritzson, D., et al.
(författare)
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Adaptive scheduling strategy optimizer for parallel rolling bearing simulation
- 2000
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Ingår i: Future generations computer systems. - 0167-739X .- 1872-7115. ; 16:5, s. 563-570
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Tidskriftsartikel (refereegranskat)abstract
- Rolling bearing simulations are very computationally intensive and need to utilize the potential of parallel computing. The load distribution over the processors in a rolling bearing simulation is very dynamic. In this paper we present the Adaptive Scheduling Strategy Optimizer (ASSO) for scheduling parallel simulations. The result of this is that the application can automatically select a near optimal scheduling strategy (with respect to the available scheduling strategies). The ASSO is used daily in real bearing simulations.
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| 3. |
- Granlund, Rego, et al.
(författare)
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Designing web-based simulation for learning
- 2000
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Ingår i: Future generations computer systems. - 0167-739X .- 1872-7115. ; 17:2, s. 171-185
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Tidskriftsartikel (refereegranskat)abstract
- Web-based simulation can be a powerful tool in education and training. The nature of simulation-based learning combined with the availability of the web make learning supported by web-based simulation a powerful strategy. In simulation-based learning, learners can experience environments that would be too costly, time-consuming, complex or dangerous to provide through other means. This article discusses some basic properties of learning using web-based simulation with the focus on different types of learning goals (instructional goals) and on proper instructional strategies (pedagogical strategies) for web-based simulation. We exemplify the classifications discussed with three web-based systems, developed by the authors, that represent different types of web-based simulation. Chernobyl — a nuclear power plant simulation. C3Fire — a micro-world supporting command and control training. ERCIS — a group distance-exercise system supporting equipment handling, action-protocol performance and group interaction.
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| 4. |
- Granlund, Rego
(författare)
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Web-based micro-world simulation for emergency management training
- 2001
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Ingår i: Future generations computer systems. - 0167-739X .- 1872-7115. ; 17:5, s. 561-572
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Tidskriftsartikel (refereegranskat)abstract
- Micro-world simulation and exercise monitoring will have an important role in future group distance exercise (GDE) systems. Micro-world simulations can be used for training basic co-ordination and collaborative work in emergency management and command-and-control situations. An important design task when developing distributed interactive simulation systems for GDE is to define a proper monitoring functionality that will help the training managers to evaluate the exercises. In our research, we have developed C3Fire, a web-based distributed interactive simulation system. This paper presents results from using the C3Fire micro-world and our work on exercise monitoring.
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| 5. |
- Holmgren, Sverker, et al.
(författare)
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The Swedish National Graduate School in Scientific Computing (NGSSC)
- 2003
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Ingår i: Future generations computer systems. - 0167-739X .- 1872-7115. ; 19, s. 1275-1283
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Swedish National Graduate School in Scientific Computing (NGSSC) was founded in 1996, and has so far admitted 75 graduate students in five nationally announced admission rounds. The aim of NGSSC is to produce PhDs with skills in strategically important disciplines together with a broad knowledge of numerical and computational techniques, and to spread the use of computations into new areas of research. NGSSC consists of both a geographical and a disciplinary network and focuses on providing core knowledge on advanced computational techniques to graduate students in application fields. This presents some special challenges to the program, such as developing its own identity and dealing with the very different backgrounds of the students. The NGSSC activities focus on a package of specially developed courses, tailored for student groups with very mixed backgrounds. The courses are given in intensive format, and are compulsory for the students participating in the program. © 2003 Elsevier B.V. All rights reserved.
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| 6. |
- Laure, Erwin
(författare)
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A Java Framework for Distributed High Performance Computing
- 2001
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Ingår i: Future generations computer systems. - 0167-739X .- 1872-7115. ; 18:2, s. 235-251
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Tidskriftsartikel (refereegranskat)abstract
- The past few years have dramatically changed the view of high performance applications and computing. While traditionally such applications have been targeted towards dedicated parallel machines, we see the emerging trend of building "meta-applications" composed of several modules that exploit heterogeneous platforms and employ hybrid forms of parallelism. In particular, Java has been recognized as modem programming language for heterogeneous distributed computing. In this paper we present OpusJava, a Java based framework for distributed high performance computing (DHPC) that provides a high level component infrastructure and facilitates a seamless integration of high performance Opus (i.e., HPF) modules into larger distributed environments. OpusJava offers a comprehensive programming model that supports the exploitation of hybrid parallelism and provides high level coordination means. (C) 2001 Elsevier Science B.V. All rights reserved.
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| 7. |
- Parrow, Joachim
(författare)
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The Expressive Power of Parallelism
- 1990
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Ingår i: Future generations computer systems. - 0167-739X .- 1872-7115. ; 6:3, s. 271-285
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Tidskriftsartikel (refereegranskat)
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| 8. |
- Afzal, Ayesha, et al.
(författare)
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Making applications faster by asynchronous execution : Slowing down processes or relaxing MPI collectives
- 2023
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Ingår i: Future generations computer systems. - : Elsevier BV. - 0167-739X .- 1872-7115. ; 148, s. 472-487
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Tidskriftsartikel (refereegranskat)abstract
- Comprehending the performance bottlenecks at the core of the intricate hardware-software inter-actions exhibited by highly parallel programs on HPC clusters is crucial. This paper sheds light on the issue of automatically asynchronous MPI communication in memory-bound parallel programs on multicore clusters and how it can be facilitated. For instance, slowing down MPI processes by deliberate injection of delays can improve performance if certain conditions are met. This leads to the counter-intuitive conclusion that noise, independent of its source, is not always detrimental but can be leveraged for performance improvements. We employ phase-space graphs as a new tool to visualize parallel program dynamics. They are useful in spotting certain patterns in parallel execution that will easily go unnoticed with traditional tracing tools. We investigate five different microbenchmarks and applications on different supercomputer platforms: an MPI-augmented STREAM Triad, two implementations of Lattice-Boltzmann fluid solvers (D3Q19 and SPEChpc D2Q37), the LULESH and HPCG proxy applications.
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| 9. |
- Aguilar, Xavier, et al.
(författare)
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Scalability analysis of Dalton, a molecular structure program
- 2013
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Ingår i: Future generations computer systems. - : Elsevier BV. - 0167-739X .- 1872-7115. ; 29:8, s. 2197-2204
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Tidskriftsartikel (refereegranskat)abstract
- Dalton is a molecular electronic structure program featuring common methods of computational chemistry that are based on pure quantum mechanics (QM) as well as hybrid quantum mechanics/molecular mechanics (QM/MM). It is specialized and has a leading position in calculation of molecular properties with a large world-wide user community (over 2000 licenses issued). In this paper, we present a performance characterization and optimization of Dalton. We also propose a solution to avoid the master/worker design of Dalton to become a performance bottleneck for larger process numbers. With these improvements we obtain speedups of 4x, increasing the parallel efficiency of the code and being able to run in it in a much bigger number of cores.
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| 10. |
- Al-Dulaimy, Auday, et al.
(författare)
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BWSLICER : A bandwidth slicing framework for cloud data centers
- 2020
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Ingår i: Future generations computer systems. - : Elsevier. - 0167-739X .- 1872-7115. ; 112, s. 767-784
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Tidskriftsartikel (refereegranskat)abstract
- Bandwidth allocation is an important and influential factor in enhancing the performance of the data centers' nodes. In this paper we propose bwSlicer, a framework for bandwidth slicing in cloud data centers, that sheds light on the virtues of effective dynamic bandwidth allocation on improving the system performance and energy efficiency. Three algorithms are investigated to deal with this issue. In the first algorithm, called Fair Bandwidth Reallocation (FBR), two virtual machines co-hosted on the same node conditionally exchange bandwidth slices based on their requirements. The second algorithm, called Required Bandwidth Allocation (RBA), periodically monitors the co-hosted virtual machines and adds/removes bandwidth slices for each of them based on their bandwidth utilization. The third algorithm, called Divide Bandwidth Reallocation (DBR), divides the bandwidth of the virtual machine into slices once it finishes its execution, and distributes the slices among the co-hosted running virtual machines according to a specific policy. The proposed bandwidth slicing algorithms are emulated in a virtualized networking environment using the Mininet network emulator. The emulation results demonstrated a promising improvement ratio in execution time and energy consumption reaching up to 30%. These results present a call for action for further research into bandwidth slicing and reallocation as a viable complement to other energy-saving techniques for enhancing the energy consumption in cloud data centers.
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