The Earth Simulator (ES), developed under the Japanese government’s initiative “Earth Simulator project”, is a highly parallel vector supercomputer system. In this paper, an overview of ES, its architectural features, hardware technology and the result of performance evaluation are described.
In May 2002, the ES was acknowledged to be the most powerful computer in the world: 35.86 teraflop/s for the LINPACK HPC benchmark and 26.58 teraflop/s for an atmospheric general circulation code (AFES). Such a remarkable performance may be attributed to the following three architectural features; vector processor, shared-memory and high-bandwidth non-blocking interconnection crossbar network.
The ES consists of 640 processor nodes (PN) and an interconnection network (IN), which are housed in 320 PN cabinets and 65 IN cabinets. The ES is installed in a specially designed building, 65 m long, 50 m wide and 17 m high. In order to accomplish this advanced system, many kinds of hardware technologies have been developed, such as a high-density and high-frequency LSI, a high-frequency signal transmission, a high-density packaging, and a high-efficiency cooling and power supply system with low noise so as to reduce whole volume of the ES and total power consumption.
For highly parallel processing, a special synchronization means connecting all nodes, Global Barrier Counter (GBC), has been introduced. 相似文献
The effect of nonuniform magnetic field on the linear and nonlinear wave propagation phenomena in two-phase pipe flow of magnetic fluid is investigated theoretically to realize the effective energy conversion system using boiling two-phase flow of magnetic fluid. Firstly, the governing equations of two-phase flow based on the unsteady thermal nonequilibrium two-fluid model are presented and the linear void wave propagation phenomena in boiling two-phase flow are numerically analyzed by using the finite volume method. Next, the nonlinear pressure wave propagation in gas-liquid two-phase flow is numerically analyzed by using the finite different method. According to these theoretical studies on the wave propagation phenomena in two-phase flow of magnetic fluid, it seems to be a reasonable proposal that the precise control of the wave propagation in two-phase flow is possible by effective use of the magnetic force. 相似文献
The recent increase in the demand for power in urban areas has caused changes in the way power is supplied. Underground distribution systems have been introduced for convenience in urban areas and to prevent injuries in case of a crisis. As a result, many new types of power cables are being used. One type, XPLE cables (also called CV cables) have been rapidly taking the place of conventional cables such as OF or SL cables since the 1960s because of their relatively easy installation and maintainability. However, distribution cables used under severe environmental conditions deteriorate rapidly (due mainly to water treeing), and some cables experience insulation breakdown. Therefore, many diagnostic methods have been developed, though they have not been very effective. By combining methods, a high reliability can be achieved in comparison to the use of a single method. However, processing the data is difficult for on-site personnel, so many experts are required. But there is a lack of qualified experts, hence we have turned to the development of expert systems. 相似文献
Skeletal form of KnbO3 crystals growing in Li2B4O7 solvent was in-situ observed at 900℃ and it was found that shallow depression started to develop on the surface of KnbO3 crystals when the crystal size exceeded several micron,typically 7 micron.Based on the quantitative criterion derived by Chernov,the estimated critical size of KNbO3 crystals was 1 micron,which was consistent with the experimental measurement.The kinetic coefficients,Kcorner and Kcr,in the criterion were experimentally obtained in the diffusive-convective and diffusive-advective flow states respectively. 相似文献
Cytogenin, 8-hydroxy-3-hydroxymethyl-6-methoxyisocoumarin, has low cytotoxicity on murine and human tumour cells in vitro. It augments or suppresses phagocytosis of macrophages and lymphocyte proliferation. It has been reported that cytogenin has a potent inhibitory effect clinically on adjuvant arthritis in Lewis rats and on type II collagen-induced arthritis in DBA/1J mice. Our experimental findings provide evidence that cytogenin has beneficial effects on spontaneous polyarthritis in MRL/1 mice and pristane-induced arthritis in DBA/1J mice. The results suggest that the mode of the anti-arthritic action of cytogenin is different from those of NSAIDs; although the precise mode of action remains unclear, cytogenin may become an excellent therapeutic agent for rheumatoid arthritis. 相似文献
Pentisomide, 2-(2-diisopropylaminoethyl)-4-methyl-2-(pyridyl)- pentanamide, is a novel antiarrhythmic agent structurally related to disopyramide. Using a glass bead arrhythmic model, the authors studied the antiarrhythmic effect of pentisomide in dogs by monitoring the plasma concentrations. When pentisomide was infused at 1 mg/kg/min for 20 min, the ventricular tachycardia was significantly reduced at 5 min after starting the infusion; the arrhythmias were reduced to less than 5% at the end of the 20 min infusion. The plasma-free concentration of pentisomide was about 3 micrograms/ml at 5 min; it increased to about 10 micrograms/ml at the end of 20 min infusion. With 0.3 mg/kg/min infusion, the arrhythmias were reduced to about 60% but were not significant at 20 min of infusion. The plasma-free concentration of pentisomide did not reach 3 micrograms/ml until 20 min of infusion. The 3 micrograms/ml plasma-free concentration for pentisomide seems to be a critical concentration in inducing a significant antiarrhythmic effect. Pentisomide dose-dependently inhibited ischaemia-reperfusion arrhythmia at doses of 30 microM and higher concentrations in vitro. In conclusion, pentisomide inhibits arrhythmias dependent with the plasma concentration or with the concentration of the external solution. The critical plasma-free concentration for inhibition of arrhythmias was 3 micrograms/ml (not equal to 10 microM) and the in vitro effect also had a similar concentration. Therefore, the in vivo and in vitro antiarrhythmic concentrations were well correlated. 相似文献