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Watanabe, So; Takahatake, Yoko; Ogi, Hiromichi*; Osugi, Takeshi; Taniguchi, Takumi; Sato, Junya; Arai, Tsuyoshi*; Kajinami, Akihiko*
Journal of Nuclear Materials, 585, p.154610_1 - 154610_6, 2023/11
Times Cited Count:0 Percentile:0.01Kawamura, Takuma; Sakamoto, Naohisa*; Osaki, Tsukasa*
Journal of Advanced Simulation in Science and Engineering (Internet), 10(1), p.31 - 39, 2023/02
Visualization of large fluid computation results at remote locations by VR, especially using volume rendering, is one of the key challenges in the visualization field. The remote visualization application CS-PBVR is capable of interactive volume rendering of large-scale data in remote locations. In this study, the image generation of CS-PBVR was extended for head-mounted displays to develop a remote VR visualization application, VR-PBVR. We also developed a function that allows manipulation of visualization data by gesture control with both hands in VR space. We applied VR-PBVR to remote volume data and confirmed that it can visualize the data at interactive frame rates.
Kawamura, Takuma; Sakamoto, Naohisa*
Dai-36-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Rombunshu (Internet), 3 Pages, 2022/12
Volume rendering is useful for visualizing computer fluid dynamics (CFD) data, and its VR visualization helps to understand complex 3D data. Volume rendering of large scale data in remote locations in VR space is an important issue of the visualization field. A remote visualization application CS-PBVR can interactively visualize the large-scale datasets in remote locations with volume rendering. In order to extend CS-PBVR into VR-PBVR which is applicable to a head mount display (HMD) Oculus rift S, we added a stereo image generation function, a gesture control function, and a renewed processing flow. VR-PBVR achieved interactive visualization of remotely located test dataset (2M cells) with 90 fps.
Sakai, Hironori; Tokunaga, Yo; Kambe, Shinsaku; Zhu, J.-X.*; Ronning, F.*; Thompson, J. D.*; Kotegawa, Hisashi*; To, Hideki*; Suzuki, Kohei*; Oshima, Yoshiki*; et al.
Physical Review B, 106(23), p.235152_1 - 235152_8, 2022/12
Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)We investigate the electronic state of Ni-substituted CeCoNiIn by nuclear quadrupole and magnetic resonance (NQR/NMR) techniques. The heavy fermion superconductivity below K for is suppressed by Ni substitutions, and reaches zero for . The In NQR spectra for and 0.25 can be explained by simulating the electrical field gradient that is calculated for a virtual supercell with density functional theory. The spin-lattice relaxation rate indicates that Ni substitution weakens antiferromagnetic correlations that are not localized near the substituent but instead are uniform in space. The temperature () dependence of for shows a maximum around K and decreases toward almost zero when temperature is further reduced as if a gap might be opening in the magnetic excitation spectrum; however, the magnetic specific heat and the static magnetic susceptibility evolve smoothly through with a dependence. The peculiar T dependence of and non-Fermi-liquid specific heat and susceptibility can be interpreted in a unified way by assuming nested antiferromagnetic spin fluctuations in a quasi-two-dimensional electronic system.
Kawamura, Takuma; Sakamoto, Naohisa*
Proceedings of 41st JSST Annual International Conference on Simulation Technology (JSST 2022) (Internet), p.266 - 269, 2022/09
Visualization of the large CFD dataset in remote locations by VR, especially using volume rendering, is one of the issues in the visualization field. The visualization library KVS supports PBVR, a unique particle-based visualization method suitable for large-scale data, and we have developed an extension of KVS for VR. In this paper, we present a design for VR extension of CS-PBVR, a remote visualization application based on KVS. The developed CS-PBVR for VR is then applied to test data and shown to be capable of VR visualization at interactive frame rates.
Noma, Yuichiro*; Kotegawa, Hisashi*; Kubo, Tetsuro*; To, Hideki*; Harima, Hisatomo*; Haga, Yoshinori; Yamamoto, Etsuji; Onuki, Yoshichika*; Ito, Kohei*; Nakamura, Ai*; et al.
Journal of the Physical Society of Japan, 90(7), p.073707_1 - 073707_5, 2021/07
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)Koyamada, Koji*; Yu, L.*; Kawamura, Takuma; Konishi, Katsumi*
International Journal of Modeling, Simulation, and Scientific Computing, 12(2), p.2140001_1 - 2140001_19, 2021/04
With the improvement of sensors technologies in various fields such as fluid dynamics, meteorology, and space observation, it is an important issue to derive explanatory models using partial differential equations (PDEs) for the big data obtained from them. In this paper, we propose a technique for estimating linear PDEs with higher-order derivatives for spatiotemporally discrete point cloud data. The technique calculates the time and space derivatives from a neural network (NN) trained on the point cloud data, and estimates the derivative term of the PDE using regression analysis techniques. In the experiment, we computed the error of the estimated PDEs for various meta-parameters for the PDEs with exact solutions. As a result, we found that increasing the hierarchy of NNs to match the order of the derivative terms in the exact solution PDEs and adopting L1 regularization with LASSO as the method of regression analysis increased the accuracy of the model.
Aoyama, Taisuke*; Kotegawa, Hisashi*; To, Hideki*; Kimura, Noriaki*; Haga, Yoshinori; Yamamoto, Etsuji; Onuki, Yoshichika*
Physica B; Condensed Matter, 570, p.349 - 351, 2019/10
Aoyama, Taisuke*; Kotegawa, Hisashi*; Kimura, Noriaki*; Yamamoto, Etsuji; Haga, Yoshinori; Onuki, Yoshichika*; To, Hideki*
Journal of the Physical Society of Japan, 88(6), p.064706_1 - 064706_7, 2019/06
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)Noma, Yuichiro*; Kotegawa, Hisashi*; Kubo, Tetsuro*; To, Hideki*; Harima, Hisatomo*; Haga, Yoshinori; Yamamoto, Etsuji; Onuki, Yoshichika*; Ito, Kohei*; Haller, E. E.*; et al.
Journal of the Physical Society of Japan, 87(3), p.033704_1 - 033704_5, 2018/03
Times Cited Count:4 Percentile:36.2(Physics, Multidisciplinary)Ogino, Chiaki*; Kahar, P.*; Lee, J. M.*; Sato, Katsuya; Ono, Yutaka; Kondo, Akihiko*
JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 105, 2016/02
Ogino, Chiaki*; Yamada, Ryosuke*; Sato, Katsuya; Ono, Yutaka
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 122, 2015/03
Nishiuchi, Mamiko; Sakaki, Hironao; Esirkepov, T. Z.; Nishio, Katsuhisa; Pikuz, T.*; Faenov, A.*; Skobelev, I. Yu.*; Orlandi, R.; Sako, Hiroyuki; Pirozhkov, A. S.; et al.
Physics of Plasmas, 22(3), p.033107_1 - 033107_8, 2015/03
Times Cited Count:69 Percentile:96.81(Physics, Fluids & Plasmas)Almost fully stripped Fe ions accelerated up to 0.9 GeV are demonstrated with a 200 TW femtosecond high-intensity laser irradiating a micron-thick Al foil with Fe impurity on the surface. An energetic low-emittance high-density beam of heavy ions with a large charge-to-mass ratio can be obtained, which is useful for many applications, such as a compact radio isotope source in combination with conventional technology.
Takayama, Yusuke*; Ikuta, Yuki*; Iizuka, Atsushi*; Kawai, Katsuyuki*; Taki, Tomihiro; Sakao, Ryota; Ichikawa, Yasuaki*
Unsaturated Soils; Research & Applications, p.659 - 665, 2014/06
In this paper, a multiple unsaturated soil barrier consisting of gravel, sand and bentonite-mixed soil layers is considered as a hardly permeable covering to prevent rainwater from infiltrating into waste deposits. Not only the quite low permeability of bentonite-mixed soil layer but also a function of capillary barrier between granular layers having different water-retention capabilities is expected to prevent water infiltration. A series of numerical simulation is carried out to evaluate performance of the multiple soil barrier using saturated/unsaturated soil/water coupled FE computation technique. The multiple unsaturated soil barrier system considered here is 10m long and 1.5 m thick consisting of sandy soil surface, sand filter, gravel layer, sand filter and bentonite-mixed clayey layer. And the soil barrier system is assumed to be placed as a covering with a 5% inclination on the waste deposit. The performance of the multiple soil barrier system is shown as a management chart to maintain impermeable ability associated with possible rainfall intensity. Particularly, in this paper, actual rainfall record in Okayama area is employed to determine the rainfall intensity which is imposed as a boundary condition in the computation. According to the simulation results, it is found that the capillary barrier is a key issue in evaluating the long term performance of the barrier system. And, it is confirmed that the barrier system considered in this paper can work well against the maximum intensity of the rainfall in the past record.
Yokota, Kumiko*; Tagawa, Masahito*; Yoshigoe, Akitaka; Teraoka, Yuden
Journal of Surface Analysis, 20(3), p.221 - 225, 2014/03
Kotegawa, Hisashi*; Nohara, Hiroki*; To, Hideki*; Matsuda, Tatsuma; Yamamoto, Etsuji; Haga, Yoshinori; Fisk, Z.; Onuki, Yoshichika; Aoki, Dai*; Flouquet, J.*
Journal of the Korean Physical Society, 63(3), p.341 - 344, 2013/08
Times Cited Count:1 Percentile:11.46(Physics, Multidisciplinary)Yokota, Kumiko*; Tagawa, Masahito*; Matsumoto, Koji*; Furuyama, Yuichi*; Kitamura, Akira*; Kanda, Kazuhiro*; Tode, Mayumi; Yoshigoe, Akitaka; Teraoka, Yuden
Protection of Materials and Structures from the Space Environment; Astrophysics and Space Science Proceedings, Vol.32, p.531 - 539, 2012/08
Tagawa, Masahito*; Kishida, Kazuhiro*; Yokota, Kumiko*; Matsumoto, Koji*; Yoshigoe, Akitaka; Teraoka, Yuden; Zhang, J.*; Minton, T. K.*
Protection of Materials and Structures from the Space Environment; Astrophysics and Space Science Proceedings, Vol.32, p.547 - 555, 2012/08
Nishiuchi, Mamiko; Pirozhkov, A. S.; Sakaki, Hironao; Ogura, Koichi; Esirkepov, T. Z.; Tanimoto, Tsuyoshi; Kanasaki, Masato; Yogo, Akifumi; Hori, Toshihiko; Sagisaka, Akito; et al.
Physics of Plasmas, 19(3), p.030706_1 - 030706_4, 2012/03
Times Cited Count:6 Percentile:25.89(Physics, Fluids & Plasmas)A 7 MeV proton beam collimated to 16 mrad containing more than particles is experimentally demonstrated by focusing a 2J, 60 fs pulse of a Ti:sapphire laser onto targets of different materials and thicknesses placed in a millimeter scale conical holder. The electric potential induced on the target holder by laser-driven electrons accelerates and dynamically controls a portion of a divergent quasi-thermal proton beam originated from the target, producing a quasi-monoenergetic "pencil" beam.
Koswattage, K.; Shimoyama, Iwao; Baba, Yuji; Sekiguchi, Tetsuhiro; Nakagawa, Kazumichi*
Applied Surface Science, 258(4), p.1561 - 1564, 2011/12
Times Cited Count:6 Percentile:29.31(Chemistry, Physical)Adsorption behavior of atomic deuterium on a hexagonal boron nitride (h-BN) thin film is studied by photon-stimulated ion desorption (PSID) of D and near edge X-ray absorption fine structure (NEXAFS) at the B and N K-edges. After the adsorption of atomic deuterium, D desorption yield (h) shows clear enhancement at the B K-edge and almost no enhancement at the N K-edge. NEXAFS spectra show a large change in the B K-edge and a small change in the N K-edge after the adsorption. We propose selective adsorption of atomic deuterium on the h-BN thin film based on the experimental results, and mention the effectiveness of applying the PSID method with X-ray to study hydrogen storage materials.