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Your search keyword '"Umeda, T."' showing total 75 results
Start Over Author "Umeda, T." Publisher elsevier b.v.
75 results on '"Umeda, T."'

12. Mesons above T c

Author

de Forcrand, Ph., Pérez, M.García, Hashimoto, T., Hioki, S., Matsufuru, H., Miyamura, O., Nakamura, A., Stamatescu, I.-O., Takaishi, T., and Umeda, T.

Published
2002
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30. A new numerical method for simulating the solar wind Alfvén waves: Development of the Vlasov–MHD model

Author

Nariyuki, Y., Umeda, T., Kumashiro, T., and Hada, T.

Subjects
*SOLAR wind, *MAGNETOHYDRODYNAMIC waves, *SOLAR photosphere, *LONGITUDINAL method, *NUMERICAL analysis, *MATHEMATICAL models, *SOLAR corona, *SUN
Abstract

Abstract: A novel scheme of plasma simulation particularly suited for computing the one-dimensional nonlinear evolution of parallel propagating solar wind Alfvén waves is presented. The scheme is based on the Vlasov and the MHD models, for solving the longitudinal and the transverse components, respectively. As long as the nonlinearity is not very large (so that the longitudinal and transverse components are well separated), our Vlasov–MHD model can correctly describe evolution of finite amplitude parallel Alfvén waves, which are typical in the solar wind, both in the linear and nonlinear stages. The present model can be applied to discussions of phenomena where the parallel Alfvén waves play major roles, for example, the solar coronal heating and solar wind acceleration by the Alfvén waves propagating from the photosphere. [Copyright &y& Elsevier]

Published
2011
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31. Comparison of chest dual-energy subtraction digital tomosynthesis imaging and dual-energy subtraction radiography to detect simulated pulmonary nodules with and without calcifications a phantom study.

Author

Gomi T, Nakajima M, Fujiwara H, Umeda T, Gomi, Tsutomu, Nakajima, Masahiro, Fujiwara, Hiroki, and Umeda, Tokuo

Abstract

Rationale and Objectives: To compare the effectiveness of chest dual-energy subtraction digital tomosynthesis (DES-DT) imaging with that of DES radiography for detecting simulated pulmonary nodules with and without calcifications. Materials and Methods: A DES-DT and DES radiography system (SonialVision Safire II, Shimadzu Co, Kyoto, Japan) with pulsed x-rays and rapid kV switching was used to detect simulated pulmonary nodules (5 and 7 mmφ, ground-glass opacity). Low-voltage (60 kVp), high-voltage (120 kVp), and soft-tissue or bone-subtracted tomograms of the desired layer thicknesses were reconstructed from the image data acquired during a single tomographic scan using a three-dimensional filtered back-projection algorithm, bone- and soft tissue‑subtracted images, and a scan angle of 40°. In the analysis, we considered the signal-to-noise ratio (SNR) computed for various sizes and degree of calcification of the simulated pulmonary nodules. We examined 30 samples with and 30 samples without different degrees of simulated pulmonary nodules by both DES radiography and DES-DT imaging. Based on the evaluations of five thoracic radiologists, receiver operating characteristic curves were compared to assess the detection accuracy of the two methods. Results: SNR and quality of images obtained by DES-DT imaging were significantly superior to those obtained by DES radiography. Based on the results of the ROC analysis, the detection accuracy of DES-DT was significantly greater than that of DES radiography (7 mmφ without calcification P < .03; with calcification P < .003). Conclusion: DES-DT imaging exhibited greater sensitivity than DES radiography for detecting simulated nodules, especially large nodules, with and without calcifications. [ABSTRACT FROM AUTHOR]

Published
2011
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32. Knee osteoarthritis, knee joint pain and aging in relation to increasing serum hyaluronan level in the Japanese population.

Author

Inoue, R., Ishibashi, Y., Tsuda, E., Yamamoto, Y., Matsuzaka, M., Takahashi, I., Danjo, K., Umeda, T., Nakaji, S., and Toh, S.

Abstract

Summary: Objective: To investigate relationship between serum hyaluronan (HA) level and the presence and severity of radiographic knee osteoarthritis (OA) as well as degree of knee pain in Japanese population. Design: A total of 616 volunteers participated in this study. Based on the Kellgren–Lawrence (K–L) grade, participants were radiographically classified into three groups: Normal (K–L grade 0 or 1), Moderate (grade 2) and Severe (grade 3 or 4). The degree of knee pain was quantified by visual analogue scale (VAS) and Knee injury and Osteoarthritis Outcome Score (KOOS) Pain. Serum HA levels were compared among the Normal, Moderate and Severe groups, and the relationship between serum HA level and the severity of knee OA was analyzed after age, sex and body mass index (BMI) were adjusted. In addition, the correlation between serum HA level and the degree of knee pain was analyzed in each group. Results: Regarding relationship between serum HA level and the severity of radiographic knee OA, serum HA levels of the Moderate and Severe groups were significantly higher than in the Normal group (P <0.001). Furthermore, serum HA level correlated with the severity of radiographic knee OA (r =0.289, P <0.001) after adjusting for age, sex and BMI. Serum HA level correlated with VAS of knee pain and/or KOOS Pain in the Normal and Moderate groups. Conclusion: Serum HA level has the potential to be useful for the diagnosis of the presence and severity of knee OA. [ABSTRACT FROM AUTHOR]

Published
2011
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34. Detection of accelerator-produced neutrinos at a distance of 250 km

Author

Ahn, S.H, An, S, Aoki, S, Berns, H.G, Bhang, H.C, Boyd, S, Casper, D, Chikamatsu, T, Choi, J.H, Echigo, S, Etoh, M, Fujii, K, Fukuda, S, Fukuda, Y, Gajewski, W, Golebiewska, U, Hara, T, Hasegawa, T, Hayato, Y, Hill, J, Hong, S.J, Ieiri, M, Inada, T, Inagaki, T, Ishida, T, Ishii, H, Ishii, T, Ishino, H, Ishitsuka, M, Itow, Y, Iwashita, T, Jang, H.I, Jang, J.S, Jeon, E.J, Jeong, E.M, Jung, C.K, Kadowaki, T, Kajita, T, Kameda, J, Kaneyuki, K, Kato, I, Kato, Y, Kearns, E, Kenmochi, S, Khang, B.H, Kibayashi, A, Kielczewska, D, Kim, B.J, Kim, C.O, Kim, H.I, Kim, J.H, Kim, J.Y, Kim, S.B, Kishi, S, Kitamura, M, Kobayashi, K, Kobayashi, T, Kobayashi, Y, Kohama, M, Koo, D.G, Koshio, Y, Kropp, W, Kume, G, Kusano, E, Learned, J.G, Lee, H.K, Lee, J.W, Lee, S.B, Lim, I.T, Lim, S.H, Maesaka, H, Martens, K, Maruyama, T, Matsuno, S, Mauger, C, McGrew, C, Minakawa, M, Mine, S, Miura, M, Miyamoto, S, Miyano, K, Moriyama, S, Mukai, S, Nakahata, M, Nakamura, K, Nakamura, M, Nakano, I, Nakaya, T, Nakayama, S, Nakayoshi, K, Nishijima, K, Nishikawa, K, Nishiyama, S, Noda, S, Noumi, H, Obayashi, Y, Oh, J.K, Okada, A, Onchi, M, Otaki, T, Oyama, Y, Pac, M.Y, Park, H, Park, S.H, Park, S.K, Sakai, A, Sakuda, M, Sakurai, N, Sasao, N, Sato, K, Scholberg, K, Seo, E, Sharkey, E, Shiino, K, Shima, A, Shiozawa, M, So, H, Sobel, H, Stachyra, A, Stone, J.L, Sulak, L.R, Suzuki, A, Suzuki, Y, Takasaki, M, Takatsuki, M, Takenaka, K, Takeuchi, H, Takeuchi, Y, Tamura, N, Tanaka, K.H, Tanaka, Y, Tashiro, K, Tauchi, K, Toshito, T, Totsuka, Y, Tumakov, V, Umeda, T, Vagins, M, Walter, C.W, Wilkes, R.J, Yamada, S, Yamaguchi, T, Yamanoi, Y, Yanagisawa, C, Yokoyama, H, Yoo, J, Yoshida, M, and You, S.Y

Published
2001
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49. Temporal meson correlators at finite temperature on quenched anisotropic lattice

Author

Nomura, K., Miyamura, O., Umeda, T., and Matsufuru, H.

Subjects
*CHARMONIUM, *MESONS, *QUANTUM chromodynamics, *ANISOTROPY
Abstract

We study charmonium correlators at finite temperature in quenched anisotropic lattice QCD. The smearing technique is applied to enhance the low energy part of the correlator. We use two analysis procedures: the maximum entropy method for extraction of the spectral function without assuming specific form, as an estimate of the shape of spectral function, and the χ2 fit assuming typical forms as quantitative evaluation of the parameters associated to the forms. We find that at T ≅ 0.9Tc the ground state peak has almost the same mass as at T = 0 and almost vanishing width. At T ≅ 1.1Tc our result suggests that the correlator still has nontrivial peak structure at almost the same position as below Tc with finite width. [Copyright &y& Elsevier]

Published
2003
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