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Yasumiishi, Misa*; Masoudi, P.*; Nishimura, Taku*; Ochi, Kotaro; Ye, X.*; Aldstadt, J.*; Komissarov, M.*
Radiation Measurements, 168, p.106978_1 - 106978_16, 2023/11
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)In this study, we surveyed air dose rates using hand-held and backpack-type scintillators in a forest of deciduous and evergreen trees in Fukushima Prefecture, Japan. The effects of topographic features on air dose rates were examined using multivariate adaptive regression splines (MARS) against five selected topographic parameters. The air dose rates were distributed unevenly in the forest, and air dose rates varied by more than 1Sv/h as a function of time, likely owing to ground wetness etc. The effect of different topographic parameters varied between survey dates. The MARS model predictions with all topographic parameters yielded an R of 0.54 or higher. To discuss whether the effect of topography on air dose rates and soil contamination levels is consistent, air dose rates measured in the field were compared with those estimated from the depth profile of radiocesium in soil. Most air dose rates estimated from the soil samples were in the range of field measurements.
Kawamura, Takuma; Idomura, Yasuhiro; Miyamura, Hiroko; Takemiya, Hiroshi
Journal of Visualization, 20(1), p.151 - 162, 2017/02
Times Cited Count:3 Percentile:18.26(Computer Science, Interdisciplinary Applications)In this paper, we propose a novel transfer function design interface for multivariate volume rendering. In the conventional multivariate volume rendering, GUI based transfer function design interfaces were limited to two-dimensional variables space. In order to design higher dimensional transfer functions in an interactive and intuitive manner, a Transfer Function Synthesizer (TFS) is developed. On the TFS, multi-dimensional transfer functions are generated by algebraic synthesis of one-dimensional transfer functions, which are designed based on the conventional GUIs or algebraic expressions. The TFS enables not only multivariate volume rendering but also general visualization techniques such as surface visualization and image composition within the framework of volume rendering. The TFS is implemented on the remote visualization system PBVR, and applied to various multivariate scalar volume data generated from nuclear applications.
Kawamura, Takuma; Noda, Tomoyuki; Idomura, Yasuhiro
Proceedings of 2nd Workshop on In Situ Infrastructures for Enabling Extreme-scale Analysis and Visualization (ISAV 2016) (Internet), p.18 - 22, 2016/11
Times Cited Count:9 Percentile:90.83(Computer Science, Interdisciplinary Applications)A novel in-situ online visualization framework is developed based on the Particle Based Volume Rendering (PBVR), which renders multivariate volume data using view-independent particle data. Our online approach enables visualization of particle data with interactive view exploration and changes of multi-dimensional transfer functions at runtime. The runtime visualization show excellent strong scaling up to thousands of cores, and its computational cost is small. These features enable flexible in-situ data exploration for monitoring extreme scale simulations. The utility of the proposed framework is demonstrated by applying it to simulations of molten debris relocation in reactor pressure vessels using the JUPITER code.
Kawamura, Takuma; Idomura, Yasuhiro; Miyamura, Hiroko; Takemiya, Hiroshi
Proceedings of SIGGRAPH Asia 2015 (SA 2015) (Internet), 4 Pages, 2015/00
In this paper, we propose a novel transfer function design technique for multivariate volume rendering. This technique generates a multidimensional transfer function by logical synthesis of variables and transfer functions. This technique enables analysts to extract correlation of variables and to combine multivariate surface and volume shapes. And this technique is implemented in Remote Visualization System PBVR optimized to several supercomputers. An experiment for the multi-phase fuel melting simulation result in the nuclear energy field shows the powerful ability of this technique enough by extracting complex behavior of molten materials.
Ishigami, Tsutomu; Kobayashi, Kensuke; Umemoto, Michitaka; Matsunaga, Takeshi
Reliability Engineering & System Safety, 86(1), p.61 - 74, 2004/10
Times Cited Count:3 Percentile:12.11(Engineering, Industrial)no abstracts in English
JAERI-M 82-079, 164 Pages, 1982/08
no abstracts in English
Miyamura, Hiroko; Kawakami, Yoshiaki; Suzuki, Yoshio; Kawamura, Takuma; Nakajima, Norihiro
no journal, ,
When analyzing objects in mechanical design, the simulation results show physical data such as von Mises stress, distortion, maximum stress, and mean stress. These results can not only confirm already known phenomena but also provide new insights. Therefore, we propose a technique for visualizing the distribution changes over time of multi-variable datasets via graphical representation.
Nishi, Shusaku*; Saito, Takumi*; Watanabe, Yusuke; Miyakawa, Kazuya
no journal, ,
no abstracts in English
Nagayama, Sakiko*; Okazaki, Kodai*; Kawakami, Tomohiko*; Abe, Yuta; Makuuchi, Etsuyo*; Otaka, Masahiko
no journal, ,
no abstracts in English
Tateishi, Ryo*; Shimada, Koji; Iwamori, Akiyuki*; Ogita, Yasuhiro; Wada, Shinya*; Kunimatsu, Wataru*; Otsuka, Yoshiharu*
no journal, ,
It has been demonstrated that active faults (strike-slip faults) and non-active faults developed in granitic rocks in Japan can be discriminated with high probability by linear discriminant analysis using chemical compositions of fault gouge samples. Although, the result included that a reverse fault type active fault was discriminated on the inactive fault side. In this study, to confirm whether this result is due to the difference in fault type or the difference in rock body, chemical composition and linear discriminant analysis of the fault gouge of active reverse faults, active strike-slip faults, and non-active faults in the Kojyaku granite were carried out. As a result, the discrimination rate between active and inactive faults was 100% for 13 (chemical) components and 7 components selected by AIC, and 90% for 3 components. This result suggests the possibility that the difference in the granite bodies affected the discrimination more than the difference of their fault type.