PSTEP: Project for solar-terrestrial environment prediction

Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.

Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12

https://doi.org/10.1186/s40623-021-01486-1

The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.

Visualization of overlay network using autonomous system relationships

Miyamura, Hiroko; Hu, H.-Y.*; Yoshida, Masahiro*; Ozahata, Satoshi*; Nakao, Akihiro*; Takahashi, Shigeo*

Shingaku Giho, 112(463), p.577 - 582, 2013/03

This report presents a method for visualizing scale-free networks including Overlay networks as an typical example. Visualizing large-scale and complicated networks such as social networks has recently been very popular while conventional network visualization techniques cannot allow us to understand the topological structure of the scale-free networks. This is because the vertex degrees vary at an exponential rate in the scale-free network and thus special attention should be given when visualizing the network connectivity and analyzing the network traffic there. In this report, we employ the hierarchical representation of the scale-free network by referring to their vertex degrees and autonomous system relationships, so that we can clearly visualize the topological structure of the network in 3D space and retrieve the traffic paths over the network.

Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2006

Nishio, Kazuhisa; Matsuoka, Toshiyuki; Mikake, Shinichiro; Tsuruta, Tadahiko; Amano, Kenji; Oyama, Takuya; Takeuchi, Ryuji; Saegusa, Hiromitsu; Hama, Katsuhiro; Yoshida, Haruo*; et al.

JAEA-Review 2009-001, 110 Pages, 2009/03

JAEA-Review-2009-001.pdf:49.84MB

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the project is under the Construction Phase. This document presents the following results of the research and development performed in 2006 fiscal year, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration.

Ectopic Endoreduplication caused by sterol alteration results in serrated petals in

Hase, Yoshihiro; Fujioka, Shozo*; Yoshida, Shigeo*; Sun, G.; Umeda, Masaaki*; Tanaka, Atsushi

Journal of Experimental Botany, 56(414), p.1263 - 1268, 2005/04

https://doi.org/10.1093/jxb/eri122

The () mutant, that has serrated petals and sepals but no other large changes in plant morphology, was studied. The had a mutation in and an altered sterol composition. It was found that the mutation causes ectopic endoreduplication in petal tips that do not normally endoreduplicate. The rosette leaves of also showed an enhanced level of endoreduplication, but their morphology was hardly affected. These facts suggest that the suppression of endoreduplication is important for petal morphogenesis and the normal sterol composition is required for this suppression.

Measurement of radiation skyshine with D-T neutron source

Yoshida, Shigeo*; Nishitani, Takeo; Ochiai, Kentaro; Kaneko, Junichi*; Hori, Junichi; Sato, Satoshi; Yamauchi, Michinori*; Tanaka, Ryohei*; Nakao, Makoto*; Wada, Masayuki*; et al.

Fusion Engineering and Design, 69(1-4), p.637 - 641, 2003/09

https://doi.org/10.1016/S0920-3796(03)00196-0

no abstracts in English

The Report of inspection and repair technology of sodium cooled reactors

Kisohara, Naoyuki; Uchita, Masato; Konomura, Mamoru; Kasai, Shigeo; Soman, Yoshindo; Shimakawa, Yoshio; Hori, Toru; Chikazawa, Yoshitaka; Miyahara, Shinya; Hamada, Hirotsugu; et al.

JNC TN9400 2003-002, 109 Pages, 2002/12

JNC-TN9400-2003-002.pdf:8.12MB

Sodium is the most promising candidate of an FBR coolant because of its excellent properties such as high thermal conductivity. Whereas, sodium reacts with water/air and its opaqueness makes it difficult to inspect sodium components. These weaknesses of sodium affect not only plant safety but also plant availability (economy). To overcome these sodium weak points, the appropriate countermeasure must be adopted to commercialized FBR plants. This report describes the working group activities for sodium/water reaction of steam generators (SG), in-service inspection for sodium components and sodium leak due to sodium components boundary failure. The prospect of each countermeasure is discussed in the viewpoint of the commercialized FBR plants. (1)Sodium/water reaction. The principle of the countermeasure for sodium/water reaction accidents was organized in the viewpoint of economy (the investment of SG and the plant availability). The countermeasures to restrain failure propagation were investigated for a large-sized SG. Preliminary analysis revealed the possibility of minimizing tubes failure propagation by improving the leak detection system and the blow down system. Detailed failure propagation analysis will be required and the early water leak detection system and rapid blow down system must be evaluated to realize its performance. (2)In-service inspection (ISI&R). The viewpoint of the commercialized plant's ISI&R was organized by comparing with the prototype reactor's ISI&R method. We also investigated short-term ISI&R methods without sodium draining to prevent the degrading of the plant availability, however, it is difficult to realize them with the present technology. Hereafter, the ISI&R of the commercialized plants must be defined by considering its characteristics. (3)Sodium leak from the components. This report organized the basic countermeasure policy for primary and secondary sodium leak accidents. Double-wall structure of sodium piping was ...

The Arabidopsis dwf7/ste1 mutant is defective in the sterol C-5 desaturation step leading to brassinosteroid biosynthesis

Choe, S.*; Noguchi, Takahiro*; Fujioka, Shozo*; Takatsuto, Suguru*; Tissier, C. P.*; Gregory, B. D.*; Ross, A. S.*; Tanaka, Atsushi; Yoshida, Shigeo*; Tax. F. E.*; et al.

Plant Cell, 11, p.207 - 221, 1999/02

https://doi.org/10.1105/tpc.11.2.207

no abstracts in English

A Multilevel graph layout for analysing of large-scale network datasets

Miyamura, Hiroko; Yoshida, Masahiro*; Ozahata, Satoshi*; Takahashi, Shigeo*; Nakao, Akihiro*; Kawashima, Konosuke*

no journal, , 

We propose a multilevel graph layout technique for visualizing large scale network datasets. Large-scale datasets are said to be difficult to analyze and visualize. However, with our technique, the datasets can be displayed in multistep. For instance the outline of network dataset is shown first, and when focused on a certain region, the detailed information is shown as well. By using this technique, users can observe a large scale dataset from the outline to the detail seamlessly, and therefore this is valuable for the structural analysis of network datasets.

Neutron spectrum measurement in assemblies simulating ITER/TBM by means of multi-foil activation method

Tatebe, Yosuke; Yoshida, Shigeo*; Ochiai, Kentaro; Sato, Satoshi; Kondo, Keitaro; Onishi, Seiki; Takakura, Kosuke; Konno, Chikara; Wada, Masayuki*

no journal, , 

no abstracts in English

Development of advanced neutronics/thermal-hydraulics coupling simulation system, 12; Uncertainty evaluation in developed measurement method for gas-liquid two-phase flow inside a fuel bundle using LDV

Ono, Ayako; Okamoto, Kaoru*; Makino, Yasushi*; Hosokawa, Shigeo*; Yoshida, Hiroyuki

no journal, , 

JAEA has been developing an advanced neutronic/thermal-hydraulics coupling simulation system. In the coupling code, the detailed thermal-hydraulics codes based on an interface-capturing method (JUPITER or TPFIT) will be adopted to simulate thermal-hydraulics in a fuel bundle. The experimental data and findings relating to the two-phase flow in a fuel bundle are needed to validate the JUPITER/TPFIT codes. In the previous study, we proposed a new measurement method to measure the bubbly flow in a narrow channel, such as a subchannel, by combining laser-doppler velocimetry and photodiodes. In this study, we evaluate the uncertainty in the new measurement method arising from the signal processing and the method of the determination for bubble signals, using the newly developed LDV optical path simulator.