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Matsukawa, Shun*; Itakura, Kenichi*; Hayano, Akira; Suzuki, Yukinori*
Journal of MMIJ, 133(11), p.256 - 263, 2017/11
LIDAR detects a rock mass surface configurations as a point cloud. DiAna (Discontinuity Analysis) is a Matlab tool which was developed for geo-structural analysis of rock mass discontinuities. DiAna segments a point cloud into bounding boxes to estimate the surface of a rock mass. However, an expert's skills necessary to determine the appropriate size of the bounding boxes for DiAna. We developed the VBS (Variable-Box Segmentation) algorithm to determine the appropriate box size depending on the location of the point cloud and to estimate the surface of a rock mass. The performance of the VBS algorithms was evaluated by comparison with the DiAna algorithm. The results of comparison showed that the VBS algorithm estimated planes more accurately for the reference planes than the DiAna algorithm. Therefore, the VBS algorithm determines appropriate box sizes automatically depending on the location of the point cloud and estimates the surface appropriately.
Urano, Hajime; Fujita, Takaaki*; Ide, Shunsuke; Miyata, Yoshiaki; Matsunaga, Go; Matsukawa, Makoto
Fusion Engineering and Design, 100, p.345 - 356, 2015/11
Times Cited Count：16 Percentile：79.46(Nuclear Science & Technology)The operation scenarios for plasma breakdown and current ramp-up phases in JT-60SA tokamak have been developed. The induced current in the in-vessel conducting elements such as vacuum vessel and stabilizing plate increases to the comparable level of plasma current of 
600 kA during the breakdown phase and thus enhances the strength of error field. The optimized scenarios for half and full pre-magnetization cases satisfied the conditions required for the plasma initiation. At the initial plasma, the vertical magnetic field required to sustain the plasma position was controlled by the outer equilibrium field (EF) coil currents which compensate for a vertical field due to a large eddy current. The condition for the formation of divertor configurations given by the combination of the magnetic flux for plasma and the plasma current enables us to develop the operational scenarios with a smooth transition from a limiter to a divertor configuration.
Hayano, Akira; Matsukawa, Shun*; Xu, Z.*; Itakura, Kenichi*
Proceedings of 8th Asian Rock Mechanics Symposium (ARMS-8) (USB Flash Drive), 9 Pages, 2014/10
In generally, the geological observation of a gallery wall is performed based on geologists' traditional techniques. However, to reduce the differences in data quality attributable to geologists' individual judgments and experiences, it is necessary to provide a method to acquire objective data that are unaffected by a geologist's subjectivity. It is also necessary to reduce the work volume associated with geological observations of gallery walls. Three-dimensional laser scanning (3DLS) is useful as a means for achieving this goal. In this study, acquisition of geometric data of fractures distributed on the gallery wall has been conducted using 3DLS data while clarifying the geological observation data necessary for modeling of a fractured rock mass. The acquired geometric data of fractures were compared with data acquired by a geologist. Consequently, the fractures were extracted by visible reading of images generated from 3DLS data, then geometric data was generated.
Novello, L.*; Gaio, E.*; Piovan, R.*; Takechi, Manabu; Ide, Shunsuke; Matsukawa, Makoto
Fusion Engineering and Design, 86(1), p.33 - 40, 2011/01
Times Cited Count：10 Percentile：60.88(Nuclear Science & Technology)Matsukawa, Makoto; Kikuchi, Mitsuru; Fujii, Tsuneyuki; Fujita, Takaaki; Hayashi, Takao; Higashijima, Satoru; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Ide, Shunsuke; Ishida, Shinichi; et al.
Fusion Engineering and Design, 83(7-9), p.795 - 803, 2008/12
Times Cited Count：17 Percentile：72.86(Nuclear Science & Technology)no abstracts in English
Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Hayashi, Nobuhiko; Urata, Kazuhiro*; Miura, Yushi; Kizu, Kaname; Tsuchiya, Katsuhiko; Morioka, Atsuhiko; Kudo, Yusuke; et al.
Plasma Science and Technology, 6(1), p.2141 - 2150, 2004/02
Times Cited Count：2 Percentile：6.49(Physics, Fluids & Plasmas)The dominant issue for the the modification program of JT-60 (JT-60SC) is to demonstrate the steady state reactor relevant plasma operation. Physics design on plasma parameters, operation scenarios, and the plasma control method are investigated for the achievement of high-
. Engineering design and the R&D on the superconducting magnet coils, radiation shield, and vacuum vessel are performed. Recent progress in such physics and technology developments is presented.
Ishida, Shinichi; Abe, Katsunori*; Ando, Akira*; Chujo, T.*; Fujii, Tsuneyuki; Fujita, Takaaki; Goto, Seiichi*; Hanada, Kazuaki*; Hatayama, Akiyoshi*; Hino, Tomoaki*; et al.
Nuclear Fusion, 43(7), p.606 - 613, 2003/07
no abstracts in English
Ishida, Shinichi; Abe, Katsunori*; Ando, Akira*; Cho, T.*; Fujii, Tsuneyuki; Fujita, Takaaki; Goto, Seiichi*; Hanada, Kazuaki*; Hatayama, Akiyoshi*; Hino, Tomoaki*; et al.
Nuclear Fusion, 43(7), p.606 - 613, 2003/07
Times Cited Count：33 Percentile：69.14(Physics, Fluids & Plasmas)no abstracts in English
Hosogane, Nobuyuki; Ninomiya, Hiromasa; Matsukawa, Makoto; Ando, Toshiro; Neyatani, Yuzuru; Horiike, Hiroshi*; Sakurai, Shinji; Masaki, Kei; Yamamoto, Masahiro; Kodama, Kozo; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.368 - 385, 2002/09
Times Cited Count：2 Percentile：17.03(Nuclear Science & Technology)This paper reviews developments of the JT-60U tokamak and coil power supplies and their operational experiences obtained to date. The JT-60U is a large tokamak upgraded from the original JT-60 to obtain high plasma current, large plasma volume and highly elongated divertor configurations. In the modification, all components inside the bore of toroidal magnetic field coils, a vacuum vessel, poloidal magnetic field coils (PF-coils), divertor etc., were renewed. Furthermore, boron carbide converted CFC tiles were used as divertor tiles to reduce erosion of carbon-base tiles. Later, a semi-closed divertor with pumps was installed in the replacement of the open divertor. Various technologies and ideas introduced to develop these components their operational experiences provide important data for designing future tokamaks. Also, major troubles that had influence on the JT-60U operations are described. As a maintenance issue for tokamaks using deuterium fueling gas, a method for reducing radiation exposure of in-vessel workers are introduced.
Omori, Yoshikazu; Matsukawa, Makoto; Omori, Shunzo; Terakado, Tsunehisa; Okano, Jun; Noda, Masaaki*
NIFS-MEMO-36, p.358 - 361, 2002/06
no abstracts in English
Matsukawa, Makoto; Ishida, Shinichi; Sakasai, Akira; Kurita, Genichi; Miura, Yushi; Terakado, Tsunehisa; Omori, Yoshikazu; Omori, Shunzo; Okano, Jun; Shimada, Katsuhiro; et al.
Fusion Technology, 39(2-Part2), p.1106 - 1110, 2001/03
no abstracts in English
Tsuji, Shunji; Neyatani, Yuzuru; Hosogane, Nobuyuki; Matsukawa, Makoto; ; Totsuka, Toshiyuki; Kimura, Toyoaki
JAERI-M 91-196, 36 Pages, 1991/11
no abstracts in English
Ninomiya, Hiromasa; Hosogane, Nobuyuki; Yoshino, Ryuji; Ushigusa, Kenkichi; Kamada, Yutaka; Kikuchi, Mitsuru; Kimura, Toyoaki; Kurihara, Kenichi; Tsuji, Shunji; Naito, Osamu; et al.
Kaku Yugo Kenkyu, 65(SPECIAL ISSUE), p.13 - 26, 1991/03
no abstracts in English
Matsunaga, Go; Takechi, Manabu; Sakurai, Shinji; Ide, Shunsuke; Matsukawa, Makoto; Oyama, Naoyuki; Aiba, Nobuyuki; Kurita, Genichi; Ferro, A.*; Gaio, E.*; et al.
no journal, ,
Matsunaga, Go; Takechi, Manabu; Sakurai, Shinji; Ide, Shunsuke; Oyama, Naoyuki; Matsukawa, Makoto; Aiba, Nobuyuki; Urano, Hajime; Sakasai, Akira; Kamada, Yutaka; et al.
no journal, ,
no abstracts in English
ribbon system ACuMo
O
(A=Rb, Cs)Fujimura, Akio*; Yasui, Yukio*; Kono, Yohei*; Kittaka, Shunichiro*; Sakakibara, Toshiro*; Igawa, Naoki; Matsukawa, Takeshi*; Yoshida, Yukihiko*; Hoshikawa, Akinori*; Ishigaki, Toru*
no journal, ,
The magnetic behavior and magnetic structure of ACuMoO (A=Rb, Cs) with CuO ribbon chains have been studied by using specific heat measurement and neutron diffraction method. CsCuMoO showed collinear-antiferromagnetic structure analyzed by the neutron diffraction. The relation between magnetic behavior and magnetic for those materials are discussed.
(R=rare earth elements)Yasui, Yukio*; Miyamoto, Takuma*; Kori, Shunsuke*; Terasaki, Ichiro*; Yoshizawa, Daichi*; Mitsuru, Akaki*; Hagiwara, Masayuki*; Matsukawa, Takeshi*; Yoshida, Yukihiko*; Hoshikawa, Akinori*; et al.
no journal, ,
We have measured the specific heat and magnetization up to 50 T of polycrystalline samples of RCrTiO (R=Pr, Nd, Eu, Sm and Gd) and also carried out powder neutron diffraction experiments of NdCrTiO and Nd
PrCrTiO. From the analyses of specific heat data and magnetization curves up to 50 T of the systems, we have evaluated the magnetic interactions between the Cr
- Cr magnetic moments and between the Cr -R ones. The temperature dependence of neutron magnetic reflection intensities of NdCrTiO indicate that both the Cr-moments and the Nd-moments simultaneously order at 
. Basis of the obtained magnetic behavior, the mechanism of magnetoelectric effect of RCrTiO will be discussed.
Hayano, Akira; Saito, Ryoko*; Matsukawa, Shun*; Itakura, Kenichi*; Suzuki, Yukinori*; Matsuoka, Toshiyuki; Sato, Toshinori
no journal, ,
no abstracts in English
Matsuura, Yuto*; Matsukawa, Shun*; Itakura, Kenichi*; Hayano, Akira; Suzuki, Yukinori*
no journal, ,
no abstracts in English
Matsukawa, Shun*; Itakura, Kenichi*; Hayano, Akira; Matsuura, Yuto*; Suzuki, Yukinori*
no journal, ,
