Parallel computing systems

An independent but complementary approach has been the development of parallel computing systems, where many processors can be concurrently applied in cooperation on a single calculation. This idea is certainly not new. It has already been the subject of numerous research projects and a very vast... 

FIGURE 3.5 Traditional high-performance computing model. Authorized users log in and submit jobs to the parallel computing system remotely. The remote system executes computations and saves the results. Users may download the results to their local machines. 

The development and efficient implementation of a parallel direct SCF Hartree-Fock algorithm, with gradients and random phase approximation solutions, are described by Feyereisen and Kendall, who discussed details of the structure of the parallel version of DISCO. Preliminary results for calculations using the Intel-Delta parallel computer system were reported. The data showed that the algorithms were efficiently parallelized and that throughput of a one-processor Cray X-MP was reached with about 16 nodes on the Intel-Delta. The data also indicated that sequential code, which was not a bottleneck on traditional supercomputers, became time-critical on parallel computers. 

Distributed Memory Memory that is apportioned to a specific node of a parallel computing system. A given node can directly access the memory on that node only. 

A. Trew and G. Wilson, Eds., Past, Present, Parallel A Survey of Available Parallel Computing Systems, Springer-Verlag, London, 1991. 

In an attempt to circumvent the computational complexity of matrix inversion, some researchers are pursuing solutions for the joint accelerations which have a linear recursive form. The inversion of the in tia matrix is explicitly avoided. The resulting linear recursive algorithms have a reduced computational complexity which is 0(N). This is the second basic solution approach to the Direct Dynamics problem, and it has been rqjplied to serial open chains [3,7], single closed chains [22], and some more genoal multibody systems [4, 37]. It is believed that the structure of linear recursive algorithms may also facilitate their implementation on parallel computer systems. 

The entire reconstruction in 3D of an object is quite time consuming at present. Techniques are being developed, howevei to speed up the measurement process, combining fast detector systems, high-speed data networks, and parallel computing systems. 

The simulation was successfully implemented for a maximum of 40,000 particles, of which up to 30% carried the sticky binder a parallel computer system at the University of Illinois at Urbana-Champaign and a Sun computer cluster at CCNY were used. To limit the complexity of the code and to keep computer running time to acceptable levels (12 14 hours), it was necessary to assume that particles covered with binder (fluid) at the onset of binder introduction were the only ones carrying the binder for the duration of computations. In other words, sticky binder-covered particles always remained sticky with a constant fluid layer on them, while dry (unsticky) particles remained always dry, and no binder transfer between particles was allowed during a particular run. Additional binder could be introduced at set intervals but only to make more (or less) particles sticky which then remained binder covered for the duration of the run. 

The ultimate goal of Feller and Jordan s work is to produce a potential that accurately represents the interaction of water with a carbon nanotube. Their next study will involve HjO interacting with a cluster model of a carbon nanotube. However, this will require access to the next generation massively parallel computing system from Hewlett-Packard that is currendy being installed in EMSL s Molecular Science Computing Facility. " ... 

Segmentation of Tumor in Digital Mammograms Using Wavelet Transform Modulus Maxima on a Low Cost Parallel Computing System... 

Parallel Computing System (PCS) is a system based on parallel processing conception that uses multiple processors which run simultaneously and operate independently. In the system each processor has its own private Internet Protocol (IP) address, memory and space to store data. The data is shared via a communication network. The performance of a PCS depends on the specification of each processor and the memory capacity available in the system. 

Arsmah, A. Norma, S. Hanifah and Y. S. Salmah. (2009) Active Contour Model on Digital Mammograms Using Low-Cost Parallel Computing Systems. Proceeding of ICORAFFS. 

Because of the structure of Monte Carlo algorithms, the QMC method is readily adaptable to parallel computer systems. This aspect has not been exploited to date. One anticipates, however, that as more researchers learn about the weak... 

To accommodate the possible chemical reactions of the ongoing corrosion process, the calculated concentrations at c (t -i- At) (cfin Fig. 32.3) must be corrected according to the local thermodynamic equilibrium. For this purpose, the concentrations c (t + At) are transferred into a thermodynamic subroutine ThermoScript [10], which contains the commercial program ChemApp [11]. ChemApp is based on a numerical Gibbs energy minimization routine in combination with tailor-made databases [12]. In order to avoid excessive calculation times, the parallel-computing system PVM (parallel virtual machine) is used, i.e., ThermoScript distributes the individual... 

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