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Takahashi, Shigeo*; Sakurai, Daisuke*; Nagao, Fumiya; Kurikami, Hiroshi; Sanada, Yukihisa
Shimyureshon, 42(2), p.68 - 75, 2023/06
This paper introduces a case in which scientific knowledge on understanding the deposition process of radionuclides and evaluating the dose rate reduction due to decontamination work was obtained through visual analysis based on data on the spatio-temporal distribution of air dose rates accumulated through radiation monitoring after the accident. We will discuss the prospects for future efforts to effectively obtain important knowledge that will assist in the planning of policies for reconstruction from the nuclear power plant accident in the future.
Takahashi, Shigeo*; Kurikami, Hiroshi; Sanada, Yukihisa; Sakurai, Daisuke*
ERAN FY2022 Annual Report (Internet), 1 Pages, 2023/04
This study aims to establish a highly accurate evaluation technique for decontamination effects through multilateral and quantitative evaluation of decontamination effects. The applicability of the visual analysis technique was confirmed through a trial analysis.
Takahashi, Tomoyuki*; Fukaya, Yukiko*; Iimoto, Takeshi*; Uni, Yasuo*; Kato, Tomoko; Sun, S.*; Takeda, Seiji; Nakai, Kunihiro*; Nakabayashi, Ryo*; Uchida, Shigeo*; et al.
Hoken Butsuri (Internet), 56(4), p.288 - 305, 2021/12
We report the results of activities related to the Task Group of Parameters Used in Biospheric Dose Assessment Models for Radioactive Waste Disposal at the Japan Health Physics Society.
Takahashi, Shigeo*; Sakurai, Daisuke*; Sasaki, Miyuki; Miyamura, Hiroko; Sanada, Yukihisa
Visual Computer, 37(12), p.3039 - 3050, 2021/12
Times Cited Count：0 Percentile：0.01(Computer Science, Software Engineering)The Fukushima nuclear accident in 2011 raised awareness on the importance of radioactive deposition processes, especially for proposing aerosol measures against possible air pollution. However, identifying these types of processes is often difficult due to complicated terrains. This paper presents an application study for identifying radioactive deposition processes by taking advantage of visual interaction with topographic data. The idea is to visually investigate the correspondence of the spatial positions to the air dose rate along with relevant attributes. This is accomplished by composing scatterplots of pairwise attributes, onto which we project terrain areas to interactively find specific patterns of such attributes. We applied our approach to the analysis of air dose rate distribution data around the Fukushima nuclear plant after the accident. Our visualization technique clearly distinguished contamination areas derived from different deposition processes, and thus is useful for elucidation of the deposition process.
Takahashi, Tomoyuki*; Uchida, Shigeo*; Takeda, Seiji; Nakai, Kunihiro*
KURNS-EKR-11, p.97 - 102, 2021/03
This paper outlines the status of IAEA database compilation for migration parameters depending elements in a biosphere such as soil-to-plant transfer factor and bioconcentration factor of marine products, and the status of utilization of the database in dose evaluation of radioactive waste disposal in Japan. Additionally, in the case of applying a new database to the dose evaluation for future radioactive waste disposal in a specific area. We summarized the opinions of specialists and result of general discussion about future strategies to make a new database for their parameters, perspectives to be considered in it, issues, etc.
Cl in soil near the Fukushima Dai-ichi Nuclear Power PlantOta, Yuki*; Sueki, Keisuke*; Sasa, Kimikazu*; Takahashi, Tsutomu*; Matsunaka, Tetsuya*; Matsumura, Masumi*; Tosaki, Yuki*; Honda, Maki*; Hosoya, Seiji*; Takano, Kenta*; et al.
JAEA-Conf 2018-002, p.99 - 102, 2019/02
no abstracts in English
Wu, H.-Y.*; Takahashi, Shigeo*; Miyamura, Hiroko; Ozahata, Satoshi*; Nakao, Akihiro*
Electronic Imaging, 2017(1), p.118 - 130, 2017/01
Extracting hierarchical structures from networks provides us with an effective means of visualizing them, especially when they contain complicated node connectivities such as those in traffic and distributed networks. This paper presents an algorithm for inferring such partial orders by optimizing the network hierarchies along flow paths that are given as input. We study several network examples to demonstrate the feasibility of the proposed approach including course dependency charts, railway networks, and P2P networks.
Wu, H.-Y.*; Takahashi, Shigeo*; Miyamura, Hiroko; Ozahata, Satoshi*; Nakao, Akihiro*
Journal of Imaging Science and Technology, 60(6), p.060407_1 - 060407_13, 2016/11
Times Cited Count：0 Percentile：0.02(Imaging Science & Photographic Technology)Extracting hierarchical structures from networks provides us with an effective means of visualizing them, especially when they contain complicated node connectivities such as those in traffic and distributed networks. This paper presents an algorithm for inferring such partial orders by optimizing the network hierarchies along flow paths that are given as input. We study several network examples to demonstrate the feasibility of the proposed approach including course dependency charts, railway networks, and P2P networks.
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.
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Sakurai, Daisuke; Saeki, Osamu*; Carr, H.*; Wu, H.-Y.*; Yamamoto, Takahiro*; Duke, D.*; Takahashi, Shigeo*
IEEE Transactions on Visualization and Computer Graphics, 22(1), p.945 - 954, 2016/01
Times Cited Count：5 Percentile：41.49(Computer Science, Software Engineering)Scalar topology in the form of Morse theory has provided computational tools that analyze and visualize data from scientific and engineering tasks. Contracting isocontours to single points encapsulates variations in isocontour connectivity in the Reeb graph. For multivariate data, isocontours generalize to fibers inverse images of points in the range, and this area is therefore known as fiber topology. However, fiber topology is less fully developed than Morse theory, and current efforts rely on manual visualizations. This paper therefore shows how to accelerate and semi-automate this task through an interface for visualizing fiber singularities of multivariate functions : . This interface exploits existing conventions of fiber topology, but also introduces a 3D view based on the extension of Reeb graphs to Reeb spaces. Validation of the interface is performed by assessing whether the interface supports the mathematical workflow both of experts and of less experienced mathematicians.
Komoto, Shigeo*; Chuko, Tomotaka*; Hisamatsu, Shugo; Okuda, Yasuhiro*; Masu, Hyuma*; Takahashi, Masahiro*; Kishikawa, Keiki*
Crystal Growth & Design, 15(6), p.2723 - 2731, 2015/05
Times Cited Count：16 Percentile：75.03(Chemistry, Multidisciplinary)Piezoluminescence and liquid crystallinity of anthracene-based bispyridinium salts were investigated in stimulus responsive luminescent organic crystals and luminescent ionic liquid crystals. The salts possess an anthracene moiety as a fluorophore in their center, and the pyridiniums attached to the anthracene moiety are substituted with trialkoxybenzyl groups. Single crystals of the salts bearing two trimethoxybenzyl groups were obtained as solvates. Ethyl acetate, acetone, and dioxane solvates of the chlorides have almost the same crystal structures with one-dimensional channels. Grinding of the solvated crystals caused the extrusion of the included solvent molecules, which resulted in the red shifts of their fluorescence in the solid state. Tris(octyloxy)benzyl and tris(dodecyloxy)benzyl derivatives exhibited rectangular columnar liquid crystals upon being heated for their bromide and tetrafluoroborate salts and upon being cooled for their hexafluorophosphate salts.
Hisamatsu, Shugo; Masu, Hyuma*; Takahashi, Masahiro*; Kishikawa, Keiki*; Komoto, Shigeo*
Crystal Growth & Design, 15(5), p.2291 - 2302, 2015/04
Times Cited Count：77 Percentile：98.08(Chemistry, Multidisciplinary)Anthracene derivatives possessing a carbamate group and an ester group at their 9- and 10-positions, respectively, were prepared to furnish pairwise packing of anthracene fluorophores in their crystal structures. They were nonluminescent in ethanol solution and showed AIE (aggregation-induced emission) in aqueous ethanol solution and in solid state. Crystal structure analysis of them showed that the H-bonding networks involved in their crystal structures could be classified into four patterns, H-bonding between the carbamate and the ester carbonyl (motifA), H-bonding between the carbamate and the ester oxygen atom (motif B), H-bonded cyclic dimer of carbamate moieties (motif C), and H-bonded chain among carbamate moieties (motif D). Compounds with pairwisely packed anthracene fluorophores showed dimer emission with the longer fluorescence wavelength than others without the pair formation.
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.
) irradiated with helium ion beamChiba, Naoki*; Arakawa, Kozue*; Itabashi, Takeru*; Nakamura, Shigeo*; Takahashi, Nobuyuki*; Iwasaki, Yasunaga*; Yoshihara, Ryohei; Nozawa, Shigeki; Hase, Yoshihiro; Narumi, Issei
JAEA-Review 2009-041, JAEA Takasaki Annual Report 2008, P. 72, 2009/12
no abstracts in English
Nagatani, Taketeru; Asano, Takashi; Fujiwara, Shigeo; Takahashi, Saburo
Proceedings of INMM 50th Annual Meeting (CD-ROM), 10 Pages, 2009/00
By implementation of the Integrated Safeguards Approach, the inspection scheme of JNC-1 site was transferred from the scheduled inspections to RII with short notice. The development of RII was considered under the precondition that it would be conducted without interruption of facility operation. JAEA proposed verification procedures to mitigate the influence on facility operation by the RII. The influence on facility operation by inspection activities of RII was drastically mitigated in comparison with the traditional IIV though implementation of the RII required additional efforts of the operator. This paper reports JAEA's efforts for implementation of RII with short notice in order to mitigate the influence of facility operation by inspection and the impact it has on the facility operation from the operator's standpoint.
Asano, Takashi; Fujiwara, Shigeo; Takahashi, Saburo; Nagatani, Taketeru; Fukuhara, Junichi; Kodani, Yoshiki; Kimura, Takashi; Miura, Yasushi
Proceedings of INMM 50th Annual Meeting (CD-ROM), 10 Pages, 2009/00
JAEA commenced to consider the integrated safeguards (IS) approach for JNC-1 site as the new concept of safeguards for further reduction of influence of facility operation by the safeguards activity. On the other hand, the board of governors of IAEA led the broader conclusion to Japan on June 2004 and safeguards implementation in Japan was transferred to the IS scheme in September 2004. IAEA aimed to improve efficiency of safeguards implementation for the plutonium handling facility by optimization of use of advanced safeguards systems and new safeguards regime without reduction of effectiveness of safeguards. The IS approach for JNC-1 site was developed and implemented on August 2008 after many discussions among IAEA, Japan Safeguards Office (JSGO) and JAEA. This paper shows contributions by JAEA to development of this approach from the operator's view point and influence to the operator by implementation of IS approach.
Nagatani, Taketeru; Asano, Takashi; Fujiwara, Shigeo; Takahashi, Saburo
Proceedings of JAEA-IAEA Workshop on Advanced Safeguards Technology for the Future Nuclear Fuel Cycle (Internet), 8 Pages, 2007/11
Safeguards implementation in Japan was transferred to an integrated safeguards (IS) scheme in September 2004. Around that time, IS approach was implemented for all of the light water reactors and LEU fuel fabrication facilities. Based on the SAGSI advice, the JAEA developed an IS approach for Plutonium Fuel Production Facility (PFPF) and proposed to the IAEA. Based on the JAEA proposal, the IAEA proposed the IS approach for not only PFPF but also for other facilities in the JNC-1 site in May 2005. The concept for this approach was agreed upon between the IAEA and the Japan side in November 2006. The IAEA has a target to start implementation of the IS approach for the JNC-1 site in January 2008. This report introduces the IS approach for MOX fuel fabrication facilities in the JNC-1 site and considers the perspective for the future.
Asano, Takashi; Fujiwara, Shigeo; Takahashi, Saburo; Nemoto, Tadayuki*; Sato, Takashi*; Kuniyasu, Kazufusa*; Hiruta, Kazuhiko*
Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-28-Kai Nenji Taikai Rombunshu (CD-ROM), 11 Pages, 2007/00
JAEA has developed and demonstrated the Remote Monitoring (RM) technology on the safeguards equipment at the storage area in PFPF to improve the efficiency of the inspection activity. JAEA is considering the expansion of the RM technology to the safeguards equipment in the process area to improve the efficiency of the inspection activity under the integrated safeguards. JAEA considers that the cabling cost and work in the facility will be reduced to apply the wireless LAN to the RM technology. JAEA performed the confirmatory testing of the performance of the Glove box Unattended Assay and Monitoring system (GUAM) and the remote transmission of the GUAM measurement data by the wireless LAN in cooperation with Japan Nuclear Fuel Limited. In this test, JAEA confirmed it's possible to establish the wireless LAN networking in the process area. This paper reports the applicability of the wireless LAN to the RM technology based on the results of the confirmatory testing.
Ninagawa, Junichi; Asano, Takashi; Fujiwara, Shigeo; Takahashi, Saburo; Menlove, H.*; Rael, C. D.*; Nakajima, Shinji*; Sato, Takashi*
Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-27-Kai Nenji Taikai Rombunshu (CD-ROM), 9 Pages, 2006/00
no abstracts in English
Takeshima, Yuriko; Takahashi, Shigeo*; Fujishiro, Issei*; Nielson, G. M.*
Proceedings of IEEE Visualization 2004 (VIS 2004) (CD-ROM), 2 Pages, 2004/10
no abstracts in English
