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Miyamura, Hiroko; Takemiya, Hiroshi; Wu, H.-Y.*; Takahashi, Shigeo*
Kashika Joho Gakkai-Shi, 36(143), p.152 - 156, 2016/10
Broad survey on the distribution of the air dose rate has been performed after the accident at the Fukushima Daiichi Nuclear Power Plant continuously. The surveyed monitoring datasets are stored in a database and are made available to the public. Recently, the size of the datasets have been significantly increased as more detailed measurements in space and time are available, and effective reduction of the size of the datasets is necessary for visualizing and exploring such large scale datasets. However, if the datasets are not carefully reduced, we often miss a part of important features of the distribution data. Therefore, we develop an effective Level of Detail control (LoD) method for retaining critical features of the distribution. In the method, the global and local features of the distribution are extracted by means of differential topology analyses. Then, the simplified data is created by edge collapse operation with taking into account these features of the data.
Wan, T.; Obayashi, Hironari; Sasa, Toshinobu
Kashika Joho Gakkai-Shi (USB Flash Drive), 36(Suppl.2), 8 Pages, 2016/10
Nakajima, Norihiro; Nishida, Akemi; Miyamura, Hiroko; Iigaki, Kazuhiko; Sawa, Kazuhiro
Kashika Joho Gakkai-Shi (USB Flash Drive), 36(Suppl.2), 4 Pages, 2016/10
Since nuclear power plants have dimensions approximately 100m
and their structures are an assembly made up of over 10 million components, it is not convenient to experimentally analyze its behavior under strong loads of earthquakes, due to the complexity and hugeness of plants. The proposed system performs numerical simulations to evaluate the behaviors of an assembly like a nuclear facility. The paper discusses how to carry out visual analysis for assembly such as nuclear power plants. In a result discussion, a numerical experiment was carried out with a numerical model of High Temperature engineering Test Reactor of Japan Atomic Energy Agency and its result was compared with observed data. A good corresponding among them was obtained as a structural analysis of an assembly by using visualization. As a conclusion, a visual analytics methodology for assembly is discussed.
Obayashi, Hironari; Hirabayashi, Masaru
Kashika Joho Gakkai-Shi (USB Flash Drive), 36(Suppl.2), 2 Pages, 2016/10
no abstracts in English
Kitamura, Tatsuaki*; Sakamoto, Kensaku; Takase, Kazuyuki
Kashika Joho Gakkai-Shi, 35(Suppl.2), p.59 - 60, 2015/09
no abstracts in English
Nakajima, Norihiro; Miyamura, Hiroko; Kawakami, Yoshiaki; Kawamura, Takuma
Kashika Joho Gakkai-Shi, 35(Suppl.1), p.233 - 238, 2015/07
no abstracts in English
Kitamura, Tatsuaki*; Sakamoto, Kensaku; Takase, Kazuyuki
Kashika Joho Gakkai-Shi, 32(Suppl.2), p.239 - 240, 2012/10
In the thermal-hydraulic design of supercritical water-cooled reactors, it is required to establish a thermal-hydraulic analysis method which can simulate the heat transfer and fluid flow characteristics of supercritical fluids precisely. A crossing flow is a phenomenon in which the fluid flowing through the inside of a fuel bundle in the perpendicular direction moves between subchannels to a transverse direction. The crossing flow influences the removal heat of a reactor core greatly. In the present study, results of the preliminary crossing flow simulation are described.
Mitsuhara, Masatoshi*; Harada, Erika*; Yamasaki, Shigeto*; Ikeda, Kenichi*; Hata, Satoshi*; Nakashima, Hideharu*; Otsuka, Satoshi; Kaito, Takeji
Kashika Joho Gakkai-Shi, 31(122), p.98 - 103, 2011/07
no abstracts in English
Kureta, Masatoshi; Segawa, Mariko; Takamine, Jun
Kashika Joho Gakkai-Shi, 31(122), p.116 - 121, 2011/07
In this manuscript, the fundamentals and merits of neutron visual sensing techniques, high-speed consecutive visual sensing technique, high-speed-scanning dynamic 3D visualization technique, multi-beam 3D velocimetry technique and energy-selective neutron imaging technique are summarized. These techniques have been developed mainly for the R&D of the nuclear energy system using the high-flux research reactors, JRR-3 and JRR-4, and a high-intensity pulsed neutron source, J-PARC. Very unique visualization and measurement were successfully carried out by these neutron visual sensing techniques. An energy-selective neutron imaging is extremely unique and newly developed visualization and measurement technique.
Kitamura, Tatsuaki*; Sakamoto, Kensaku; Takase, Kazuyuki
Kashika Joho Gakkai-Shi, 30(Suppl.2), p.359 - 360, 2010/10
no abstracts in English
Takase, Kazuyuki; Misawa, Takeharu; Yoshida, Hiroyuki
Kashika Joho Gakkai-Shi, 30(Suppl.2), p.25 - 26, 2010/10
In order to evaluate an influence of earthquake acceleration to the boiling two-phase flow behavior in nuclear reactors, numerical simulations were performed under the simulated earthquake condition. The two-phase flow analysis code, ACE-3D, was modified as the influence of the earth quake acceleration can calculate. To check out if the modification is adequate, a series of calculations were carried out and the following summaries were derived; (1) the void fraction in the fuel bundle receives the influence of the earthquake, (2) the liquid-phase in the two-phase flow moves in the same direction as the direction of oscillation due to the inputted earthquake acceleration, and (3) due to the density difference in comparison with the liquid phase, the gas phase of that moves in the direction opposite to the oscillating direction. This study enabled visualized evaluation of the boiling two-phase flow behavior in the nuclear reactors at the earthquake condition.
Miyamura, Hiroko; Suzuki, Yoshio; Takemiya, Hiroshi
Kashika Joho Gakkai-Shi, 30(Suppl.1), p.269 - 272, 2010/07
We propose a spatio-temporal visualization technique. The spatio-temporal visualization technique, which is created by spatio-temporal information mapping, is an information visualization technique useful for specifying the feature area from simulation and measurement results. In the map, the change of a physical quantity is allocated in two-dimensional space with spatial and temporal information in each dimension. By applying the spatio-temporal visualization technique to the three-dimensional virtual vibration simulator, we confirmed that the technique was helpful to detect the region of interest.
Miyamura, Hiroko; Shinano, Yuji*; Ozahata, Satoshi*
Kashika Joho Gakkai-Shi, 30(Suppl.1), p.273 - 276, 2010/07
We propose an adaptive visualization technique for representing a large-scale hierarchical dataset within limited display space. A hierarchical dataset has nodes and links showing the parent-child relationship between the nodes. These nodes and links are described using graphics primitives. When the number of these primitives is large, it is difficult to recognize the structure of the hierarchical data because many primitives are overlapped within a limited region. To overcome this difficulty, we propose an adaptive visualization technique for hierarchical datasets. The proposed technique selects an appropriate graph style according to the nodal density in each area.
Takase, Kazuyuki; Shobu, Takahisa; Tsukimori, Kazuyuki; Muramatsu, Toshiharu
Kashika Joho Gakkai-Shi, 29(Suppl.2), p.113 - 114, 2009/10
no abstracts in English
Obayashi, Hironari; Tasaka, Yuji*; Takeda, Yasushi*
Kashika Joho Gakkai-Shi, 26(103), p.252 - 257, 2006/10
Ultrasonic velocity profiler (UVP) has been established in fluid mechanics and fluid engineering applications of flow measurement. It is utmost importance to investigate flow structure and behavior of liquid metals when it is used in an active manner not only in heat transportation but also a flowing medium, as is the case for any kinds of situations of fluid flow is involved, and as such, fluid mechanics is applied. It is obvious that any optical method of flow measurement cannot be applied since all the liquid metals are opaque. This meant that non-invasive flow measurement was not possible until the ultrasonic measurement has been established. In the past studies, UVP has been applied to the flow measurement of liquid metal. In this paper, we show some examples which measured the liquid metal flow and introduce a new measurement system based on the UVP techniques.
Suzuki, Yoshio; Matsumoto, Nobuko; Idomura, Yasuhiro; Tani, Masayuki
Kashika Joho Gakkai-Shi, 26(Suppl.1), p.49 - 52, 2006/07
no abstracts in English
Nemoto, Hiroyuki*; Ogi, Hiromichi*; Shiina, Yasuaki; Inagaki, Terumi*
Kashika Joho Gakkai-Shi, 26(Suppl.1), p.1 - 4, 2006/07
no abstracts in English
Kume, Etsuo; Kitamura, Tatsuaki*; Takase, Kazuyuki; Ose, Yasuo*
Kashika Joho Gakkai-Shi, 25(Suppl.2), p.369 - 370, 2005/10
no abstracts in English
Takase, Kazuyuki; Ose, Yasuo*; Yoshida, Hiroyuki; Akimoto, Hajime; Aoki, Takayuki*
Kashika Joho Gakkai-Shi, 25(Suppl.1), p.435 - 436, 2005/07
no abstracts in English
Suzuki, Yoshio; Sai, Kazunori*; Ono, Nobuaki*; Koyamada, Koji*
Kashika Joho Gakkai-Shi, 24(Suppl.1), p.443 - 446, 2004/07
no abstracts in English
