Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

Let's read! We will often find out this sentence everywhere. When still being a kid, mom used to order us to always read, so did the teacher. Some books are fully read in a week and we need the obligation to support reading. What about now? Do you still love reading? Is reading only for you who have obligation? Absolutely not! We here offer you a new book enPDFd the perception of the visual world to read.

The Perception of the Visual World. By James J. Gibson. U.S.A.: Houghton Mifflin Company, 1950 (George Allen & Unwin, Ltd., London). Price 35s.

A Viking Lander 1 image was modeled as mixtures of reflectance spectra of palagonite dust, gray andesitelike rock, and a coarse rocklike soil. The rocks are covered to varying degrees by dust but otherwise appear unweathered. Rocklike soil occurs as lag deposits in deflation zones around stones and on top of a drift and as a layer in a trench dug by the lander. This soil probably is derived from the rocks by wind abrasion and/or spallation. Dust is the major component of the soil and covers most of the surface. The dust is unrelated spectrally to the rock but is equivalent to the global-scale dust observed telescopically. A new method was developed to model a multispectral image as mixtures of end-member spectra and to compare image spectra directly with laboratory reference spectra. The method for the first time uses shade and secondary illumination effects as spectral end-members; thus the effects of topography and illumination on all scales can be isolated or removed. The image was calibrated absolutely from the laboratory spectra, in close agreement with direct calibrations. The method has broad applications to interpreting multispectral images, including satellite images.

Spectral mixture modeling - A new analysis of rock and soil types at the Viking Lander 1 site. [on Mars]

Workflows and e-Science: An overview of workflow system features and capabilities

Multiagent Systems is the title of a collection of papers dedicated to surveying specific themes of Multiagent Systems (MAS) and Distributed Artificial Intelligence (DAI). All of them authored by leading researchers of this dynamic multidisciplinary field.

/pdf/multiagent-systems-a-modern-approach-to-distributed-5fon0donq1.pdf

Multiagent systems: a modern approach to distributed artificial intelligence

Grid resource management systems should take into consideration the application requirements and user preferences on the one hand and virtual organizations' polices on the other hand. In order to satisfy both users and resource owners, many metrics, criteria, and constraints should be introduced to formulate multicriteria strategies for Grid resource management problems.In this chapter we argue that Grid resource management involves multiple criteria and as such requires multicriteria decision support. We discuss available multicriteria optimization techniques and methods for user preference modeling. The influence of the Grid nature on the resource management techniques used is also emphasized, including issues such as dynamic behavior, uncertainty, and incomplete information. We present three aspects of the resource management process: (i) providing the resource management system with all the necessary information concerning accessible resources, application requirements, and user preferences, (ii) making decisions that map tasks to resources in the best possible way, and (iii) controlling the applications and adapting to changing conditions of the Grid environment.

Multicriteria aspects of Grid resource management

https://pure.uva.nl/ws/files/2365511/164764_439342.pdf

Distributed multiscale computing with MUSCLE 2, the Multiscale Coupling Library and Environment

https://isiarticles.com/bundles/Article/pre/pdf/46410.pdf

DCworms - A tool for simulation of energy efficiency in distributed computing infrastructures

Grid simulation tools provide frameworks for simulating application scheduling in various grid infrastructures. However, while experimenting with many existing tools, we have encountered two main shortcomings: (i) there are no tools for generating workloads, resources and events ; (ii) it is difficult and time consuming to model different grid levels, i.e. resource brokers, and local level scheduling systems. In this paper we present the grid scheduling simulator (GSSIM), a framework that addresses these shortcomings and provides an easy-to-use Grid scheduling framework for enabling simulations of a wide range of scheduling algorithms in multi-level, heterogeneous grid infrastructures. In order to foster more collaboration in the community at large, GSSIM is complemented with a portal (http://www.gssim.org) that provides a repository of grid scheduling algorithms, synthetic workloads and benchmarks for use with GSSIM.

Grid scheduling simulations with GSSIM

Grid computing has become one of the most important research topics that appeared in the field of computing in the last years. Simultaneously, we have noticed the growing popularity of new Web-based technologies which allow us to create application-oriented Grid middleware services providing capabilities required for dynamic resource and job management, monitoring, security, etc. Consequently, end users are able to get easier access to geographically distributed resources.

In this paper we present the results of our experiments with the Grid(Lab) Resource Management System (GRMS), which acts on behalf of end users and controls their computations efficiently using distributed heterogeneous resources. We show how resource matching techniques used within GRMS can be improved by the use of a job migration based rescheduling policy. The main aim of this policy is to shorten job pending times and reduce machine overloads. The influence of this method on application performance and resource utilization is studied in detail and compared with two other simple policies.

/pdf/dynamic-grid-scheduling-with-job-migration-and-rescheduling-20p4xwvh1j.pdf

Krzysztof Kurowski

Papers

Multicriteria aspects of Grid resource management

Distributed multiscale computing with MUSCLE 2, the Multiscale Coupling Library and Environment

DCworms - A tool for simulation of energy efficiency in distributed computing infrastructures

Grid scheduling simulations with GSSIM

Dynamic grid scheduling with job migration and rescheduling in the GridLab resource management system