Integrating Computing Resources on Multiple Grid-Enabled Job Scheduling Systems Through a Grid RPC System

We present a framework for a parallel programming model by remote procedure calls, which bridge large-scale computing resource pools managed by multiple Grid-enabled job scheduling systems. With this system, the user can exploit not only remote servers and clusters, but also the computing resources provided by Grid-enabled job scheduling systems located on different sites. This framework requires a Grid remote procedure call (RPC) system to decouple the computation in a remote node from the Grid RPC mechanism and uses document-based communication rather than connection-based communication. We implemented the proposed framework as an extension of the OmniRPC system, which is a Grid RPC system for parallel programming. We designed a general interface to easily adapt the OmniRPC system to various Grid-enabled job scheduling systems, including XtremWeb, CyberGRIP, Condor and Grid Engine. We show the preliminary performance of these implementations using a phylogenetic application. We found that the proposed system can achieve approximately the same performance as OmniRPC and can handle interruptions in worker programs on remote nodes. Yoshihiro Nakajima is a Research Fellow of the Japan Society for the Promotion of Science     

Design and implementations of Ninf: towards a global computing infrastructure

The world-wide computing infrastructure on the growing computer network technology is a leading technology to make a variety of information services accessible through the Internet for every user from the high-performance computing users through many of personal computing users. The important feature of such services is location transparency; information can be obtained irrespective of time or location in virtually shared manner. In this article, we overview Ninf, an ongoing global network-wide computing infrastructure project which allows users to access computational resources including hardware, software and scientific data distributed across a wide area network. Preliminary performance result on measuring software and network overhead is shown, and that promises the future reality of world-wide network computing.     

A parallel method for large sparse generalized eigenvalue problems using a GridRPC system

In this paper we present a master–worker type parallel method for finding several eigenvalues and eigenvectors of a generalized eigenvalue problem , where A and B are large sparse matrices. A moment-based method that finds all of the eigenvalues that lie inside a given domain is used. In this method, a small matrix pencil that has only the desired eigenvalues is derived by solving large sparse systems of linear equations constructed from A and B. Since these equations can be solved independently, we solve them on remote servers in parallel. This approach is suitable for master–worker programming models. We have implemented and tested the proposed method in a grid environment using a grid RPC (remote procedure call) system called OmniRPC. The performance of the method on PC clusters that were used over a wide-area network was evaluated.     

Performance and power consumption analysis of Arm Scalable Vector Extension

The Journal of Supercomputing - Modern CPUs not only have multiple cores but also support wide single instruction multiple data (SIMD). This trend is expected to grow in the future. In this paper,...     

High-density formation of Ge quantum dots on SiO2

We formed high-density Ge quantum dots (QDs) on an ultrathin SiO₂ layer by controlling the early stages of low-pressure chemical vapor deposition (LPCVD) with a germane gas (GeH₄) assisted by a remote plasma of pure H₂. We then characterized the electronic charged states of the QDs by an AFM/Kelvin probe technique. The formation of single crystalline Ge-QDs with an areal dot density of ∼2.0 × 10¹¹ cm⁻² was confirmed after examining the surface morphology and lattice by atomic force microscopy and transmission electron microscopy, respectively. It has been suggested that an increase in the flux of deposition precursors due to efficient decomposition of GeH₄ by a supply of hydrogen radicals and the dehydration reaction of surface OH bonds plays a role in nucleation of Ge-QDs on SiO₂. Surface passivation with hydrogen may also promote the surface migration of deposition precursors during LPCVD. The surface potential of the dots changed in a stepwise manner with respect to the tip bias due to multistep electron injection into and extraction from the Ge-QDs.     

Effect of calcium chloride on vapor-liquid equilibria of alcohol-alcohol and alcohol-water binary systems

The vapor-liquid equilibria of three alcohol-alcohol binary mixtures (methanol-ethanol, methanol-1-propanol and ethanol-1-propanol) and three alcohol-water binary mixtures (methanol-water, ethanol-water and allyl alcohol-water) containing calcium chloride were measured at 298.15 K using a flow-type apparatus. The measured data of each ternary system were correlated by the use of a semi-empirical model proposed by Hála. It was found that the model with the optimal value of the exponent β = 5.0 in the electrostatic interaction term, originally given as 3/2 by Hála, gives reasonable prediction to all the systems in this study.     

Evaluation of the continuation bit in the cyclic pipeline computer

The Cyclic Pipeline Computer (CPC) is a shared resource computer which shares its pipeline among multiple instruction streams to create distinct virtual processors. This effectively removes data dependencies which reduce the performance of highly pipelined computers. However, when executing unbalanced parallel programs, the CPC suffers from performance degradation due to synchronization overhead. In this paper we introduce a hardware extension called the continuation bit. The continuation bit controls the instruction issue and determines whether an instruction is issued from the same stream or the next stream. Simulations of various programs indicate that the continuation bit is able to balance the execution of parallel programs by exploiting instruction level parallelism.     

Influence of microstructure on fracture toughness distribution in ceramic-metal functionally graded materials

This paper deals with the influence of microstructure on fracture toughness distribution in functionally graded materials (FGMs) consisting of partially stabilized zirconia (PSZ) and austenitic stainless steel SUS 304. FGMs and non-graded composites (non-FGMs) with fine and coarse microstructures are fabricated by powder metallurgy using PSZ and two kinds of SUS 304 powders. The fracture toughness is determined by conventional tests for several non-FGMs with each material composition and by a method utilizing stable crack growth in FGMs. The obtained results on the fracture toughness are as follows: (1) The fracture toughness increases with an increase in a content of SUS 304 on both FGMs and non-FGMs. (2) On the fracture toughness of the non-FGMs, the influence of microstructure is negligible. (3) On the FGMs, the fracture toughness is higher in the FGM with fine microstructure than in the FGM with coarse microstructure. (4) The fracture toughness of the FGMs is higher than that of the non-FGMs especially in the case of fine microstructure. Finally, the residual stress in the FGMs created in a fabrication process is estimated from the difference in fracture toughness between the FGMs and non-FGMs.