Search

We have been carrying out the FLAGSHIP 2020 Project to develop the Japanese next-generation flagship supercomputer, the Post-K, recently named “Fugaku”. We have designed an original many core processor based on Armv8 instruction sets with the Scalable Vector Extension (SVE), an A64FX processor, as well as a system including interconnect and a storage subsystem with the industry partner, Fujitsu. The “co-design” of the system and applications is a key to making it power efficient and high performance. We determined many architectural parameters by reflecting an analysis of a set of target applications provided by applications teams. In this paper, we present the pragmatic practice of our co-design effort for “Fugaku”. As a result, the system has been proven to be a very power-efficient system, and it is confirmed that the performance of some target applications using the whole system is more than 100 times the performance of the K computer.

Recently, increasing power usage of HPC systems is a critical issue. Therefore, effective power saving method for eliminating electricity waste are very important to develop.

In this paper, we introduce a new and highly scalable interconnect called Tofu interconnect D that will be used in the post-K machine. This machine will officially be operational around 2021. The letter D represents high “density” node and “dynamic” packet slicing for “dual-rail” transfer. Herein we describe the design and the evaluation results of TofuD. Due to the high-density packaging, the optical link ratio of TofuD has decreased to 25% from the 66% optical link ratio of Tofu2. TofuD applies a new technique called dynamic packet slicing to reduce latency and to improve fault resilience. The evaluation results show that the one-way 8-byte Put latency is 0.49 μs. This is 31% lower than the latency of Tofu2. The injection rate per node is 38.1 GB/s which is approximately 83% of the injection rate of Tofu2. The link efficiency is as high as approximately 93%.

The collisions of translationally hot O(1D) with O2 result in two processes, translational energy relaxation and electronic quenching to O(3P). These two processes were studied in a gas cell at room temperature using the vacuum ultraviolet laser-induced fluorescence technique. The initial hot O(1D) atoms were produced by the photodissociation of N2O at 193 nm, which have average translational energies of 18.1 kcal mol-1 in the laboratory frame. Time-resolved measurements of the Doppler profiles for the hot O(1D) atoms revealed the translational energy relaxation process, whereas the quenching process was investigated by measuring both the decrease of the O(1D) concentration and the increase of the product O(3P) concentration at various delay times after the photochemical formation of the hot O(1D) atoms. From the simulation employing an elastic hard-sphere collision model with a Monte Carlo method, the hard-sphere diameter for the translational energy relaxation process of hot O(1D) by collisions with O2 ...

Prediction of light scattering is required to develop the optical measuring techniques for detecting the size and shape of an individual non-spherical particle. However, the applicability of well- known Lorentz-Mie theory is fairly limited and is unsuitable for this purpose. In this paper, we examine the feasibility of a direct solution method of Maxwell's electromagnetic wave equation for predicting the laser light scattering by a non-spherical object. It is confirmed that the Cartesian coordinate system is available for predicting light scattering, even if the shape of a scattering object is stepwise approximated based on the Cartesian coordinate system. That is, a complex coordinate system matched to the shape of a scattering object is not required. In addition, it is clarified that the electromagnetic field produced in the near field of a scattering object remarkably varies depending on its cross sectional shape even if the scattering patterns are almost same in the backward far field. This suggests that the estimation of multiple scattering effects in the optical particle sizing techniques should be conducted based on the near field scattering pattern. The method employed in this paper is suitable also for these purposes because this method can easily deal with a closely allocated group of scattering objects.

The effects of oral administration of hot water extract from autologous lysate of Lactobacillus casei (LEx) on the systolic blood pressure (SBP) were studied in spontaneously hypertensive rats (SHR). Oral doses of 10 mg/kg of LEx produced a significant decrease of the SBP of SHR, but LEx had no effect in normotensive rats. The long-term administration of LEx (1 or 10 mg/kg/day) to SHR from 5 to 17 weeks after birth suppressed the development of hypertension. LEx dialysed against distilled water was separated into a polysaccharide fraction (SG-1), a protein fraction (PR-1), and a nucleic acid fraction (NA-1), and SBP-lowering effects of these materials were investigated in SHR at the same dose (10mg/kg). The most effective material of these three was SG-1.

Xylooligosaccharides (XOS) are mainly composed of two or three xylose units with beta-1,4 linkages. They are obtained by hemicellulose hydrolysis, which is relatively abundant in the cell walls of grains. XOS increases the number of intestinal Bifidobacterium in humans, and maintains the fecal water content within the normal range. To examine the effect of XOS intake on severe constipation in pregnancy, which is predominant in the third trimester, thirty constipated pregnant women were treated with 4.2 g XOS daily for 4 wk. During the study, the clinical efficacy was assessed using a daily diary. The subjects indicated the number of stools and the clinical symptom scores. Twenty-nine subjects completed the study. The mean number of stools was 1.1 +/- 0.4 in the pre-treatment week, and increased in weeks 1-4 of XOS administration to 5.3 +/- 2.1, 5.9 +/- 2.5, 6.2 +/- 2.2 and 6.7 +/- 1.9, respectively. At the end of the study, 27 subjects could defecate spontaneously. The occurrence of very loose or very hard stools decreased and the stool consistency normalized. The stool color changed from dark to yellowish brown. No side effects were observed. XOS intake was highly effective for the reduction of severe constipation in pregnant women without adverse effects.

Lithium ion conducting glasses were prepared in the system (0.6Li2S⋅0.4SiS2)-Li3PO4 by twin-roller rapid quenching. The temperatures of glass transition (Tg) and crystallization (Tc) were determined for the glassy samples with 0-40mol% Li3PO4. The conductivity values at 25°C (σ25) were maximized and the activation energies (Ea) for conduction were minimized at the composition with 5mol% Li3PO4; the maximum σ25 value was as high as 9×10-4S⋅cm-1. Since the difference between Tg and Tc was also maximized at the same composition, it was concluded that the doping of small amounts of Li3PO4 improved both the glass stability against crystallization and the lithium ion conductivities.