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Nakamura, Keita; Hanari, Toshihide; Matsumoto, Taku; Kawabata, Kuniaki; Yashiro, Hiroshi*
Journal of Robotics and Mechatronics, 36(1), p.115 - 124, 2024/02
Baba, Keita*; Watanobe, Yutaka*; Nakamura, Keita*; Matsumoto, Taku; Hanari, Toshihide; Kawabata, Kuniaki
Proceedings of 29th International Symposium on Artificial Life and Robotics (AROB 2024) (Internet), p.751 - 756, 2024/01
Matsumoto, Taku; Hanari, Toshihide; Kawabata, Kuniaki; Yashiro, Hiroshi*; Nakamura, Keita*
Proceedings of 2023 IEEE International Conference on Robotics and Biomimetics (IEEE ROBIO 2023) (Internet), 7 Pages, 2023/12
Wang, Z.; Matsumoto, Toshinori; Duan, G.*; Matsunaga, Takuya*
Computer Methods in Applied Mechanics and Engineering, 414, p.116168_1 - 116168_49, 2023/09
Times Cited Count:3 Percentile:86.6(Engineering, Multidisciplinary)Matsumoto, Taku; Hanari, Toshihide; Kawabata, Kuniaki; Yashiro, Hiroshi*; Nakamura, Keita*
Proceedings of 22nd World Congress of the International Federation of Automatic Control (IFAC 2023) (Internet) , p.12107 - 12112, 2023/07
Matsumoto, Taku; Hanari, Toshihide; Kawabata, Kuniaki; Yashiro, Hiroshi*; Nakamura, Keita*
Proceedings of 28th International Symposium on Artificial Life and Robotics (AROB 28th 2023) (Internet), p.768 - 773, 2023/01
Nakamura, Keita; Baba, Keita*; Yoshikawa, Takuma*; Hanari, Toshihide; Kawabata, Kuniaki; Matsumoto, Taku
New Trends in Intelligent Software Methodologies, Tools and Techniques; Frontiers in Artificial Intelligence and Applications, Vol.355, p.427 - 438, 2022/09
Marumo, Kazuki*; Matsumoto, Atsumasa*; Nakano, Sumika*; Shibukawa, Masami*; Saito, Takumi*; Haraga, Tomoko; Saito, Shingo*
Environmental Science & Technology, 53(24), p.14507 - 14515, 2019/12
Times Cited Count:7 Percentile:28.45(Engineering, Environmental)Humic acids (HA) are responsible for the fate of metal ions in the environment. We developed a polyacrylamide gel electrophoresis (PAGE) technique to investigate the MW distributions of metal ion (copper ion). Combining contaminant-metal-free and high-resolution PAGE systems for HA provided accurate MW distributions for the metal ions. Coupling this system with UV-Vis spectrometry and the excitation-emission matrix (EEM) spectrometry-parallel factor analysis (PARAFAC) method revealed new insights into metal-HA complex. Interestingly, the MW distributions of the three metal ions were entirely different, indicating that the presence of specific binding environments in HA for the metal ions depending its MW. The MW distributions of five fluorescent components were associated with the metal ion distributions. Our PAGE-based methodology suggests that metal binding sites and fluorescent components in HA exhibit heterogeneity in terms of metal binding affinity and MW.
Matsumoto, Kazuya*; Idomura, Yasuhiro; Ina, Takuya*; Mayumi, Akie; Yamada, Susumu
Journal of Supercomputing, 75(12), p.8115 - 8146, 2019/12
Times Cited Count:2 Percentile:24.35(Computer Science, Hardware & Architecture)A communication-avoiding generalized minimum residual method (CA-GMRES) is implemented on a hybrid CPU-GPU cluster, targeted for the performance acceleration of iterative linear system solver in the gyrokinetic toroidal five-dimensional Eulerian code GT5D. In addition to the CA-GMRES, we implement and evaluate a modified variant of CA-GMRES (M-CA-GMRES) proposed in our previous study to reduce the amount of floating-point calculations. This study demonstrates that beneficial features of the CA-GMRES are in its minimum number of collective communications and its highly efficient calculations based on dense matrix-matrix operations. The performance evaluation is conducted on the Reedbush-L GPU cluster, which contains four NVIDIA Tesla P100 GPUs per compute node. The evaluation results show that the M-CA-GMRES is 1.09x, 1.22x and 1.50x faster than the CA-GMRES, the generalized conjugate residual method (GCR), and the GMRES, respectively, when 64 GPUs are used.
Nakata, Kotaro*; Hasegawa, Takuma*; Solomon, D. K.*; Miyakawa, Kazuya; Tomioka, Yuichi*; Ota, Tomoko*; Matsumoto, Takuya*; Hama, Katsuhiro; Iwatsuki, Teruki; Ono, Masahiko*; et al.
Applied Geochemistry, 104, p.60 - 70, 2019/05
Times Cited Count:8 Percentile:46.78(Geochemistry & Geophysics)no abstracts in English
Koyama, Taku*; Ueno, Kazuki*; Sekine, Mariko*; Matsumoto, Yoshihiro*; Kai, Tetsuya; Shinohara, Takenao; Iikura, Hiroshi; Suzuki, Hiroshi; Kanematsu, Manabu*
Materials Research Proceedings, Vol.4, p.155 - 160, 2018/05
Times Cited Count:0 Percentile:0.18(Materials Science, Characterization & Testing)Idomura, Yasuhiro; Ina, Takuya*; Mayumi, Akie; Yamada, Susumu; Matsumoto, Kazuya*; Asahi, Yuichi*; Imamura, Toshiyuki*
Proceedings of 8th Workshop on Latest Advances in Scalable Algorithms for Large-Scale Systems (ScalA 2017), p.7_1 - 7_8, 2017/11
A communication-avoiding generalized minimal residual (CA-GMRES) method is applied to the gyrokinetic toroidal five dimensional Eulerian code GT5D, and its performance is compared against the original code with a generalized conjugate residual (GCR) method on the JAEA ICEX (Haswell), the Plasma Simulator (FX100), and the Oakforest-PACS (KNL). The CA-GMRES method has higher arithmetic intensity than the GCR method, and thus, is suitable for future Exa-scale architectures with limited memory and network bandwidths. In the performance evaluation, it is shown that compared with the GCR solver, its computing kernels are accelerated by , and the cost of data reduction communication is reduced from to of the total cost at 1,280 nodes.
Terashima, Taku*; Matsuda, Yasuhiro*; Kuga, Kentaro*; Suzuki, Shintaro*; Matsumoto, Yosuke*; Nakatsuji, Satoru*; Kondo, Akihiro*; Kindo, Koichi*; Kawamura, Naomi*; Mizumaki, Masaichiro*; et al.
Journal of the Physical Society of Japan, 84(11), p.114715_1 - 114715_4, 2015/11
Times Cited Count:4 Percentile:34.72(Physics, Multidisciplinary)Terashima, Taku*; Matsuda, Yasuhiro*; Kuga, Kentaro*; Suzuki, Shintaro*; Matsumoto, Yosuke*; Nakatsuji, Satoru*; Kondo, Akihiro*; Kindo, Koichi*; Kawamura, Naomi*; Mizumaki, Masaichiro*; et al.
Journal of Physics; Conference Series, 592(1), p.012020_1 - 012020_6, 2015/03
Times Cited Count:1 Percentile:43.09(Physics, Atomic, Molecular & Chemical)Valence fluctuation phenomena in rare-earth intermetallic compounds have attracted attention because the quantum criticality of the valence transition has been proposed theoretically. Recently, it was found that -YbAlB shows quantum criticality without tuning and has a strong mixed-valence state. In this study, we measured the magnetization curve and X-ray magnetoabsorption in -YbAlFeB (), which is a locally isostructural polymorph of -YbAlB. The magnetization and X-ray experiments were performed in fields up to 55 and 40 T, respectively. A small increase in the Yb valence was observed at fields where the magnetization curve exhibited a change in slope.
Tsukasaki, Yoshikazu*; Miyazaki, Naoyuki*; Matsumoto, Atsushi; Nagae, Shigenori*; Yonemura, Shigenobu*; Tanoue, Takuji*; Iwasaki, Kenji*; Takeichi, Masatoshi*
Proceedings of the National Academy of Sciences of the United States of America, 111(45), p.16011 - 16016, 2014/11
Times Cited Count:38 Percentile:63.49(Multidisciplinary Sciences)Yamada, Mitsugu*; Tamada, Taro; Takeda, Kazuki*; Matsumoto, Fumiko*; Ono, Hiraku*; Kosugi, Masayuki*; Takaba, Kiyofumi*; Shoyama, Yoshinari*; Kimura, Shigenobu*; Kuroki, Ryota; et al.
Journal of Molecular Biology, 425(22), p.4295 - 4306, 2013/11
Times Cited Count:21 Percentile:50.49(Biochemistry & Molecular Biology)NADH-Cytochrome reductase (b5R), a flavoprotein consisting of NADH and flavin adenine dinucleotide (FAD) binding domains, catalyzes electron transfer from the two-electron carrier NADH to the one-electron carrier cytochrome (Cb5). The crystal structures of both the fully reduced form and the oxidized form of porcine liver b5R were determined. In the reduced b5R structure determined at 1.68 resolution, the relative configuration of the two domains was slightly shifted in comparison with that of the oxidized form. This shift resulted in an increase in the solvent-accessible surface area of FAD and created a new hydrogen-bonding interaction between the N5 atom of the isoalloxazine ring of FAD and the hydroxyl oxygen atom of Thr66, which is considered to be a key residue in the release of a proton from the N5 atom. The isoalloxazine ring of FAD in the reduced form is flat as in the oxidized form and stacked together with the nicotinamide ring of NAD. Determination of the oxidized b5R structure, including the hydrogen atoms, determined at 0.78 resolution revealed the details of a hydrogen-bonding network from the N5 atom of FAD to His49 via Thr66. Both of the reduced and oxidized b5R structures explain how backflow in this catalytic cycle is prevented and the transfer of electrons to one-electron acceptors such as Cb5 is accelerated. Furthermore, crystallographic analysis by the cryo-trapping method suggests that re-oxidation follows a two-step mechanism. These results provide structural insights into the catalytic cycle of b5R.
Okane, Tetsuo; Kawasaki, Ikuto; Yasui, Akira; Okochi, Takuo*; Takeda, Yukiharu; Fujimori, Shinichi; Saito, Yuji; Yamagami, Hiroshi; Fujimori, Atsushi; Matsumoto, Yuji*; et al.
Journal of the Physical Society of Japan, 80(Suppl.A), p.SA060_1 - SA060_3, 2011/07
Times Cited Count:1 Percentile:11.3(Physics, Multidisciplinary)Okane, Tetsuo; Okochi, Takuo*; Takeda, Yukiharu; Fujimori, Shinichi; Yasui, Akira; Saito, Yuji; Yamagami, Hiroshi; Fujimori, Atsushi; Matsumoto, Yuji*; Sugi, Motoki*; et al.
Physica Status Solidi (B), 247(3), p.397 - 399, 2010/03
Okane, Tetsuo; Okochi, Takuo*; Takeda, Yukiharu; Fujimori, Shinichi; Yasui, Akira; Saito, Yuji; Yamagami, Hiroshi; Fujimori, Atsushi; Matsumoto, Yuji*; Sugi, Motoki*; et al.
Physical Review Letters, 102(21), p.216401_1 - 216401_4, 2009/05
Times Cited Count:28 Percentile:77.03(Physics, Multidisciplinary)Hakoda, Teruyuki; Matsumoto, Kanae; Mizuno, Akira*; Narita, Tadashi*; Kojima, Takuji; Hirota, Koichi
IEEE Transactions on Industry Applications, 44(6), p.1950 - 1956, 2008/11
Times Cited Count:3 Percentile:34.14(Engineering, Multidisciplinary)Oxidation of xylene and its irradiation-induced organic byproducts in air using Ag-loaded TiO (Ag/TiO) beds was studied under electron beam (EB) irradiation. The Ag/TiO beds were placed in an irradiation or a non-irradiation space in order to identify the oxidation of xylene/its byproducts by EB irradiation, by catalytic process, and by a combination of the two. Placement of the Ag/TiO bed to the irradiation space resulted in the suppression of xylene decomposition. On the other hand, production of CO was observed in the gas phase of the irradiation space and on the surface of the Ag/TiO pellets placed both in the irradiation and non-irradiation spaces. The concentration of CO became higher when the layer was placed in the non-irradiation space. The production of CO was enhanced by loading of Ag to the TiO pellet surface. The highest concentration of CO was obtained for Ag/TiO with Ag contents greater than 5wt%.