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2,154 results on '"Yokota Y"'

1. What is the Definition of General Medicine and Generalists in Japan? [Letter]

Author

Yokota Y, Otsuka Y, and Otsuka F

Subjects
Medicine (General), R5-920
Abstract

Yuya Yokota, Yuki Otsuka, Fumio Otsuka Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558, JapanCorrespondence: Yuki Otsuka, Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan, Tel +81-86-235-7342, Fax +81-86-235-7345, Email otsuka@s.okayama-u.ac.jp

Published
2024

2. Comparison of optical spectra between asteroids Ryugu and Bennu: II. High-precision analysis for space weathering trends

Author

Yumoto, K., Tatsumi, E., Kouyama, T., Golish, D. R., Cho, Y., Morota, T., Kameda, S., Sato, H., Rizk, B., DellaGiustina, D. N., Yokota, Y., Suzuki, H., de León, J., Campins, H., Licandro, J., Popescu, M., Rizos, J. L., Honda, R., Yamada, M., Sakatani, N., Honda, C., Matsuoka, M., Hayakawa, M., Sawada, H., Ogawa, K., Yamamoto, Y., Lauretta, D. S., and Sugita, S.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Physics - Space Physics
Abstract

The influence of space weathering on the observed spectra of C-complex asteroids remains uncertain. This has long hindered our understanding of their composition through telescope observations. Multi-band imaging of Ryugu by ONC-T on Hayabusa2 and that of Bennu by MapCam on OSIRIS-REx found opposite spectral trends of space weathering; Ryugu darkened/reddened while Bennu brightened/blued. How the spectra of Ryugu and Bennu evolved relative to each other would place a constraint for understanding their origins and evolutions. In this study, we compared the space weathering trends on Ryugu and Bennu by applying the results of cross calibration between ONC-T and MapCam. We show that the average Bennu surface is brighter by 18.0 $\pm$ 1.5% at 550 nm and bluer by 0.18 $\pm$ 0.03 $\mu$m$^{-1}$ (480-850 nm slope) than Ryugu. The spectral slopes of surface materials are more uniform on Bennu than on Ryugu at spatial scales $\gtrsim$1 m, but Bennu is more heterogeneous at $\lesssim$1 m. This suggests that lateral mixing due to resurfacing may have been more efficient on Bennu. The reflectance-spectral slope distributions of craters on Ryugu and Bennu appeared to follow two trend lines with an offset before cross calibration, but they converged to a single straight trend without a bend after cross calibration. We show that the spectra of the freshest craters on Ryugu and Bennu are indistinguishable within the uncertainty of cross calibration. These results suggest that Ryugu and Bennu initially had similar spectra before space weathering and that they evolved in completely opposite directions along the same trend line, subsequently evolving into asteroids with different disk-averaged spectra. These findings further suggest that space weathering likely expanded the spectral slope variation of C-complex asteroids, implying that they may have formed from materials with more uniform spectral slopes.

Published
2024
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3. Comparison of optical spectra between asteroids Ryugu and Bennu:I. Cross calibration between Hayabusa2/ONC-T and OSIRIS-REx/MapCam

Author

Yumoto, K., Tatsumi, E., Kouyama, T., Golish, D. R., Cho, Y., Morota, T., Kameda, S., Sato, H., Rizk, B., DellaGiustina, D. N., Yokota, Y., Suzuki, H., de Leon, J., Campins, H., Licandro, J., Popescu, M., Rizos, J. L., Honda, R., Yamada, M., Sakatani, N., Honda, C., Matsuoka, M., Hayakawa, M., Sawada, H., Ogawa, K., Yamamoto, Y., Lauretta, D. S., and Sugita, S.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Asteroids (162173) Ryugu and (101955) Bennu observed by Hayabusa2 and OSIRIS-REx share many properties, but spectral observations by the telescopic Optical Navigation Camera (ONC-T) and MapCam detected subtle but significant differences, which may reflect differences in their origin and evolution. Comparing these differences on the same absolute scale is necessary for understanding their causes. However, ONC-T and MapCam have a large imager-to-imager systematic error of up to 15% caused by the difference in radiometric calibration targets. To resolve this problem, we cross calibrated albedo and color data between the two instruments using the Moon as the common calibration standard. The images of the Moon taken by ONC-T and MapCam were compared with those simulated using photometry models developed from lunar orbiter data. Our results show that the cross-calibrated reflectance of Ryugu and Bennu can be obtained by upscaling the pre-cross-calibrated reflectance of Bennu by 13.3 +/- 1.6% at b band, 13.2 +/- 1.5% at v band, 13.6 +/- 1.7% at w band, and 14.8 +/- 1.8% at x band, while those for Ryugu are kept the same. These factors compensate for the imager-to-imager bias caused by differences in targets used for radiometric calibration and solar irradiance models used for data reduction. Need for such large upscaling underscore the importance of using the cross-calibrated data for accurately comparing the Ryugu and Bennu data. The uncertainty in these factors show that the reflectance of Ryugu and Bennu can be compared with <2% accuracy after applying our results. By applying our cross calibration, the geometric albedo of Bennu became consistent with those observed by ground-based telescopes and OVIRS. Our result can be simply applied by multiplying a constant to the publicly available data and enables accurate comparison of the optical spectra of Ryugu and Bennu in future studies.

Published
2023
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4. Comparison of optical spectra between asteroids Ryugu and Bennu: I. Cross calibration between Hayabusa2/ONC-T and OSIRIS-REx/MapCam

Author

Yumoto, K., Tatsumi, E., Kouyama, T., Golish, D.R., Cho, Y., Morota, T., Kameda, S., Sato, H., Rizk, B., DellaGiustina, D.N., Yokota, Y., Suzuki, H., de León, J., Campins, H., Licandro, J., Popescu, M., Rizos, J.L., Honda, R., Yamada, M., Sakatani, N., Honda, C., Matsuoka, M., Hayakawa, M., Sawada, H., Ogawa, K., Yamamoto, Y., Lauretta, D.S., and Sugita, S.

Published
2024
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10. Evidence of global space weathering by solar wind on asteroid 162173 Ryugu

Author

Hiroi, T., Milliken, R.E., Robertson, K.M., Schultz, C.D., Amano, K., Nakamura, T., Yurimoto, H., Noguchi, T., Okazaki, R., Naraoka, H., Yabuta, H., Sakamoto, K., Yada, T., Nishimura, M., Nakato, A., Miyazaki, A., Yogata, K., Abe, M., Okada, T., Usui, T., Yoshikawa, M., Saiki, T., Tanaka, S., Nakazawa, S., Yokota, Y., Tatsumi, E., Tsuda, Y., Tachibana, S., Fuyuto, T., Watanabe, S., Sasaki, S., Kaiden, H., Kitazato, K., and Matsuoka, M.

Published
2023
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12. Particle size distributions inside and around the artificial crater produced by the Hayabusa2 impact experiment on Ryugu

Author

Ogawa, K., Sakatani, N., Kadono, T., Arakawa, M., Honda, R., Wada, K., Shirai, K., Shimaki, Y., Ishibashi, K., Yokota, Y., Saiki, T., Imamura, H., Tsuda, Y., Nakazawa, S., Takagi, Y., Hayakawa, M., Yano, H., Okamoto, C., Iijima, Y., Morota, T., Kameda, S., Tatsumi, E., Cho, Y., Yoshioka, K., Sawada, H., Matsuoka, M., Yamada, M., Kouyama, T., Suzuki, H., Honda, C., and Sugita, S.

Published
2022
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14. Anomalously porous boulders on (162173) Ryugu as primordial materials from its parent body

Author

Sakatani, N., Tanaka, S., Okada, T., Fukuhara, T., Riu, L., Sugita, S., Honda, R., Morota, T., Kameda, S., Yokota, Y., Tatsumi, E., Yumoto, K., Hirata, N., Miura, A., Kouyama, T., Senshu, H., Shimaki, Y., Arai, T., Takita, J., Demura, H., Sekiguchi, T., Müller, T. G., Hagermann, A., Biele, J., Grott, M., Hamm, M., Delbo, M., Neumann, W., Taguchi, M., Ogawa, Y., Matsunaga, T., Wada, T., Hasegawa, S., Helbert, J., Hirata, N., Noguchi, R., Yamada, M., Suzuki, H., Honda, C., Ogawa, K., Hayakawa, M., Yoshioka, K., Matsuoka, M., Cho, Y., Sawada, H., Kitazato, K., Iwata, T., Abe, M., Ohtake, M., Matsuura, S., Matsumoto, K., Noda, H., Ishihara, Y., Yamamoto, K., Higuchi, A., Namiki, N., Ono, G., Saiki, T., Imamura, H., Takagi, Y., Yano, H., Shirai, K., Okamoto, C., Nakazawa, S., Iijima, Y., Arakawa, M., Wada, K., Kadono, T., Ishibashi, K., Terui, F., Kikuchi, S., Yamaguchi, T., Ogawa, N., Mimasu, Y., Yoshikawa, K., Takahashi, T., Takei, Y., Fujii, A., Takeuchi, H., Yamamoto, Y., Hirose, C., Hosoda, S., Mori, O., Shimada, T., Soldini, S., Tsukizaki, R., Ozaki, M., Tachibana, S., Ikeda, H., Ishiguro, M., Yabuta, H., Yoshikawa, M., Watanabe, S., and Tsuda, Y.

Published
2021
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16. Thermally altered subsurface material of asteroid (162173) Ryugu

Author

Kitazato, K., Milliken, R. E., Iwata, T., Abe, M., Ohtake, M., Matsuura, S., Takagi, Y., Nakamura, T., Hiroi, T., Matsuoka, M., Riu, L., Nakauchi, Y., Tsumura, K., Arai, T., Senshu, H., Hirata, N., Barucci, M. A., Brunetto, R., Pilorget, C., Poulet, F., Bibring, J.-P., Domingue, D. L., Vilas, F., Takir, D., Palomba, E., Galiano, A., Perna, D., Osawa, T., Komatsu, M., Nakato, A., Arai, T., Takato, N., Matsunaga, T., Arakawa, M., Saiki, T., Wada, K., Kadono, T., Imamura, H., Yano, H., Shirai, K., Hayakawa, M., Okamoto, C., Sawada, H., Ogawa, K., Iijima, Y., Sugita, S., Honda, R., Morota, T., Kameda, S., Tatsumi, E., Cho, Y., Yoshioka, K., Yokota, Y., Sakatani, N., Yamada, M., Kouyama, T., Suzuki, H., Honda, C., Namiki, N., Mizuno, T., Matsumoto, K., Noda, H., Ishihara, Y., Yamada, R., Yamamoto, K., Yoshida, F., Abe, S., Higuchi, A., Yamamoto, Y., Okada, T., Shimaki, Y., Noguchi, R., Miura, A., Hirata, N., Tachibana, S., Yabuta, H., Ishiguro, M., Ikeda, H., Takeuchi, H., Shimada, T., Mori, O., Hosoda, S., Tsukizaki, R., Soldini, S., Ozaki, M., Terui, F., Ogawa, N., Mimasu, Y., Ono, G., Yoshikawa, K., Hirose, C., Fujii, A., Takahashi, T., Kikuchi, S., Takei, Y., Yamaguchi, T., Nakazawa, S., Tanaka, S., Yoshikawa, M., Watanabe, S., and Tsuda, Y.

Published
2021
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18. Collisional history of Ryugu’s parent body from bright surface boulders

Author

Tatsumi, E., Sugimoto, C., Riu, L., Sugita, S., Nakamura, T., Hiroi, T., Morota, T., Popescu, M., Michikami, T., Kitazato, K., Matsuoka, M., Kameda, S., Honda, R., Yamada, M., Sakatani, N., Kouyama, T., Yokota, Y., Honda, C., Suzuki, H., Cho, Y., Ogawa, K., Hayakawa, M., Sawada, H., Yoshioka, K., Pilorget, C., Ishida, M., Domingue, D., Hirata, N., Sasaki, S., de León, J., Barucci, M. A., Michel, P., Suemitsu, M., Saiki, T., Tanaka, S., Terui, F., Nakazawa, S., Kikuchi, S., Yamaguchi, T., Ogawa, N., Ono, G., Mimasu, Y., Yoshikawa, K., Takahashi, T., Takei, Y., Fujii, A., Yamamoto, Y., Okada, T., Hirose, C., Hosoda, S., Mori, O., Shimada, T., Soldini, S., Tsukizaki, R., Mizuno, T., Iwata, T., Yano, H., Ozaki, M., Abe, M., Ohtake, M., Namiki, N., Tachibana, S., Arakawa, M., Ikeda, H., Ishiguro, M., Wada, K., Yabuta, H., Takeuchi, H., Shimaki, Y., Shirai, K., Hirata, N., Iijima, Y., Tsuda, Y., Watanabe, S., and Yoshikawa, M.

Published
2021
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19. Development of Red-Light Oxide-Scintillators and Evaluation of the Dose Rate Monitoring System for the Decommissioning

Author

Matsukura, D., primary, Kurosawa, S., additional, Yamaji, A., additional, Ohashi, Y., additional, Yokota, Y., additional, Kamada, K., additional, Sato, H., additional, Yoshino, M., additional, Hanada, T., additional, Murakami, R., additional, Horiai, T., additional, Yoshikawa, A., additional, Tanaka, H., additional, and Takata, T., additional

Published
2023
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26. Problems on invariants of knots and 3-manifolds

Author

Andersen, J. E., Askitas, N., Bar-Natan, D., Baseilhac, S., Benedetti, R., Bigelow, S., Boileau, M., Bott, R., Carter, J. S., Deloup, F., Dunfield, N., Fenn, R., Ferrand, E., Garoufalidis, S., Goussarov, M., Guadagnini, E., Habiro, H., Hansen, S. K., Harikae, T., Haviv, A., Jeong, M. -J., Jones, V., Kashaev, R., Kawahigashi, Y., Kerler, T., Kidwell, M., Kohno, T., Kricker, A., Le, T. T. Q., Lescop, C., Lin, X. -S., Masbaum, G., Massuyeau, G., Morita, S., Morton, H. R., Murakami, H., Murakami, J., Nakanishi, Y., Ohtsuki, T., Ohyama, Y., Okamoto, M., Okuda, N., Park, C. -Y., Pilo, L., Polyak, M., Przytycki, J., Roberts, J., Rourke, C., Rozansky, L., Sanderson, B., Sato, N., Shinohara, Y., Stanford, T., Stoimenow, A., Takata, T., Thurston, D., Turaev, V., Viro, O., Willerton, S., and Yokota, Y.

Subjects
Mathematics - Geometric Topology, Mathematics - Algebraic Topology, Mathematics - Quantum Algebra, 20F36, 57M25, 57M27, 57R56, 13B25, 17B10, 17B37, 18D10, 20C08, 20G42, 22E99, 41A60, 46L37, 57M05, 57M50, 57N10, 57Q10, 81T18, 81T45
Abstract

This is a list of open problems on invariants of knots and 3-manifolds with expositions of their history, background, significance, or importance. This list was made by editing open problems given in problem sessions in the workshop and seminars on `Invariants of Knots and 3-Manifolds' held at Kyoto in 2001., Comment: Edited by T. Ohtsuki. Published by Geometry and Topology Monographs at http://www.maths.warwick.ac.uk/gt/GTMon4/paper24.abs.html

Published
2004

27. Detailed Images of Asteroid 25143 Itokawa from Hayabusa

Author

Saito, J., Miyamoto, H., Nakamura, R., Ishiguro, M., Michikami, T., Nakamura, A. M., Demura, H., Sasaki, S., Hirata, N., Honda, C., Yamamoto, A., Yokota, Y., Fuse, T., Yoshida, F., Tholen, D. J., Gaskell, R. W., Hashimoto, T., Kubota, T., Higuchi, Y., Nakamura, T., Smith, P., Hiraoka, K., Honda, T., Kobayashi, S., Furuya, M., Matsumoto, N., Nemoto, E., Yukishita, A., Kitazato, K., Dermawan, B., Sogame, A., Terazono, J., Shinohara, C., and Akiyama, H.

Published
2006

28. Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Author

Nakamura, T., primary, Matsumoto, M., additional, Amano, K., additional, Enokido, Y., additional, Zolensky, M. E., additional, Mikouchi, T., additional, Genda, H., additional, Tanaka, S., additional, Zolotov, M. Y., additional, Kurosawa, K., additional, Wakita, S., additional, Hyodo, R., additional, Nagano, H., additional, Nakashima, D., additional, Takahashi, Y., additional, Fujioka, Y., additional, Kikuiri, M., additional, Kagawa, E., additional, Matsuoka, M., additional, Brearley, A. J., additional, Tsuchiyama, A., additional, Uesugi, M., additional, Matsuno, J., additional, Kimura, Y., additional, Sato, M., additional, Milliken, R. E., additional, Tatsumi, E., additional, Sugita, S., additional, Hiroi, T., additional, Kitazato, K., additional, Brownlee, D., additional, Joswiak, D. J., additional, Takahashi, M., additional, Ninomiya, K., additional, Takahashi, T., additional, Osawa, T., additional, Terada, K., additional, Brenker, F. E., additional, Tkalcec, B. J., additional, Vincze, L., additional, Brunetto, R., additional, Aléon-Toppani, A., additional, Chan, Q. H. S., additional, Roskosz, M., additional, Viennet, J.-C., additional, Beck, P., additional, Alp, E. E., additional, Michikami, T., additional, Nagaashi, Y., additional, Tsuji, T., additional, Ino, Y., additional, Martinez, J., additional, Han, J., additional, Dolocan, A., additional, Bodnar, R. J., additional, Tanaka, M., additional, Yoshida, H., additional, Sugiyama, K., additional, King, A. J., additional, Fukushi, K., additional, Suga, H., additional, Yamashita, S., additional, Kawai, T., additional, Inoue, K., additional, Nakato, A., additional, Noguchi, T., additional, Vilas, F., additional, Hendrix, A. R., additional, Jaramillo-Correa, C., additional, Domingue, D. L., additional, Dominguez, G., additional, Gainsforth, Z., additional, Engrand, C., additional, Duprat, J., additional, Russell, S. S., additional, Bonato, E., additional, Ma, C., additional, Kawamoto, T., additional, Wada, T., additional, Watanabe, S., additional, Endo, R., additional, Enju, S., additional, Riu, L., additional, Rubino, S., additional, Tack, P., additional, Takeshita, S., additional, Takeichi, Y., additional, Takeuchi, A., additional, Takigawa, A., additional, Takir, D., additional, Tanigaki, T., additional, Taniguchi, A., additional, Tsukamoto, K., additional, Yagi, T., additional, Yamada, S., additional, Yamamoto, K., additional, Yamashita, Y., additional, Yasutake, M., additional, Uesugi, K., additional, Umegaki, I., additional, Chiu, I., additional, Ishizaki, T., additional, Okumura, S., additional, Palomba, E., additional, Pilorget, C., additional, Potin, S. M., additional, Alasli, A., additional, Anada, S., additional, Araki, Y., additional, Sakatani, N., additional, Schultz, C., additional, Sekizawa, O., additional, Sitzman, S. D., additional, Sugiura, K., additional, Sun, M., additional, Dartois, E., additional, De Pauw, E., additional, Dionnet, Z., additional, Djouadi, Z., additional, Falkenberg, G., additional, Fujita, R., additional, Fukuma, T., additional, Gearba, I. R., additional, Hagiya, K., additional, Hu, M. Y., additional, Kato, T., additional, Kawamura, T., additional, Kimura, M., additional, Kubo, M. K., additional, Langenhorst, F., additional, Lantz, C., additional, Lavina, B., additional, Lindner, M., additional, Zhao, J., additional, Vekemans, B., additional, Baklouti, D., additional, Bazi, B., additional, Borondics, F., additional, Nagasawa, S., additional, Nishiyama, G., additional, Nitta, K., additional, Mathurin, J., additional, Matsumoto, T., additional, Mitsukawa, I., additional, Miura, H., additional, Miyake, A., additional, Miyake, Y., additional, Yurimoto, H., additional, Okazaki, R., additional, Yabuta, H., additional, Naraoka, H., additional, Sakamoto, K., additional, Tachibana, S., additional, Connolly, H. C., additional, Lauretta, D. S., additional, Yoshitake, M., additional, Yoshikawa, M., additional, Yoshikawa, K., additional, Yoshihara, K., additional, Yokota, Y., additional, Yogata, K., additional, Yano, H., additional, Yamamoto, Y., additional, Yamamoto, D., additional, Yamada, M., additional, Yamada, T., additional, Yada, T., additional, Wada, K., additional, Usui, T., additional, Tsukizaki, R., additional, Terui, F., additional, Takeuchi, H., additional, Takei, Y., additional, Iwamae, A., additional, Soejima, H., additional, Shirai, K., additional, Shimaki, Y., additional, Senshu, H., additional, Sawada, H., additional, Saiki, T., additional, Ozaki, M., additional, Ono, G., additional, Okada, T., additional, Ogawa, N., additional, Ogawa, K., additional, Noguchi, R., additional, Noda, H., additional, Nishimura, M., additional, Namiki, N., additional, Nakazawa, S., additional, Morota, T., additional, Miyazaki, A., additional, Miura, A., additional, Mimasu, Y., additional, Matsumoto, K., additional, Kumagai, K., additional, Kouyama, T., additional, Kikuchi, S., additional, Kawahara, K., additional, Kameda, S., additional, Iwata, T., additional, Ishihara, Y., additional, Ishiguro, M., additional, Ikeda, H., additional, Hosoda, S., additional, Honda, R., additional, Honda, C., additional, Hitomi, Y., additional, Hirata, N., additional, Hayashi, T., additional, Hayakawa, M., additional, Hatakeda, K., additional, Furuya, S., additional, Fukai, R., additional, Fujii, A., additional, Cho, Y., additional, Arakawa, M., additional, Abe, M., additional, and Tsuda, Y., additional

Published
2023
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30. Clinical application of endoscopic soft palate augmentation in the treatment of velopharyngeal insufficiency

Author

1000070397701, Isomura, E.T., Matsukawa, M., Yokota, Y., Tanaka, N., Sugiyama, C., 1000020346167, Nohara, K., 1000070397701, Isomura, E.T., Matsukawa, M., Yokota, Y., Tanaka, N., Sugiyama, C., 1000020346167, and Nohara, K.

Abstract

Isomura E.T., Matsukawa M., Yokota Y., et al. Clinical application of endoscopic soft palate augmentation in the treatment of velopharyngeal insufficiency. International Journal of Oral and Maxillofacial Surgery, (2023); https://doi.org/10.1016/j.ijom.2023.01.003., Velopharyngeal structure augmentation with the injection of autologous fat tissue into the nasal mucosa of the soft palate has been reported previously. However, as the injection points in the velopharyngeal space cannot be observed directly, these injections may be difficult to perform accurately. This report describes a new endoscope-assisted approach in which the materials for velopharyngeal structure augmentation are administered while observing the injection points directly, also enabling adjustment of the amount of material injected. A case series of five patients aged 8–16 years who underwent endoscopic soft palate augmentation under general anaesthesia is reported. Autologous fat tissue was injected into the nasal mucosa of the soft palate using a needle-type device of an endoscope, and the effects of the treatment were evaluated. The injections were performed successfully, and the velopharyngeal function was improved. This new technique of endoscopy-assisted augmentation was useful for the treatment of velopharyngeal insufficiency.

Published
2023

31. Cross calibration between Hayabusa2/ONC-T and OSIRIS-REx/MapCam for comparative analyses between asteroids Ryugu and Bennu

Author

Yumoto, K., Tatsumi, E., Kouyama, T., Golish, D. R., Kameda, S., Sato, H., Rizk, B., DellaGiustina, D. N., Yokota, Y., Suzuki, H., de León, J., Campins, H., Licandro, J., Popescu, M., Rizos, J. L., Honda, R., Yamada, M., Morota, T., Sakatani, N., Cho, Y., Honda, C., Matsuoka, M., Hayakawa, M., Sawada, H., Ogawa, K., Yamamoto, Y., Sugita, S., Lauretta, D. S., Yumoto, K., Tatsumi, E., Kouyama, T., Golish, D. R., Kameda, S., Sato, H., Rizk, B., DellaGiustina, D. N., Yokota, Y., Suzuki, H., de León, J., Campins, H., Licandro, J., Popescu, M., Rizos, J. L., Honda, R., Yamada, M., Morota, T., Sakatani, N., Cho, Y., Honda, C., Matsuoka, M., Hayakawa, M., Sawada, H., Ogawa, K., Yamamoto, Y., Sugita, S., and Lauretta, D. S.

Abstract

Proximity observations of (162173) Ryugu by the telescopic Optical Navigation Camera onboard Hayabusa2 and (101955) Bennu by MapCam onboard Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer found opposite spectral trends of space weathering on these carbonaceous asteroids. Whether the space weathering trends on these asteroids evolved from the same starting spectra would place an important constraint for understanding their relation. However, systematic error between data obtained by the two imagers needed to be reduced for accurate comparison. To resolve this problem, we cross calibrated albedo and color data using the Moon as the common standard. We show that the cross-calibrated reflectance can be obtained by upscaling the pre-cross-calibrated reflectance of Bennu by 12 +/- 2% at v-band, reducing the systematic errors down to 2%. The cross-calibrated data show that Bennu is brighter by 16 +/- 2% at v-band and bluer in spectral slope by 0.19 +/- 0.05 (/um) than Ryugu. The spectra of fresh craters on Ryugu and Bennu before cross calibration appeared to follow two parallel trend lines with offset, but they converged to a single trend after cross calibration. Such a post-cross-calibration perspective raise the possibility that Ryugu and Bennu evolved from materials with similar visible spectra but evolved in diverging directions by space weathering. The divergent evolution can be caused by the difference in space weathering dose/process and/or composition of the starting material. Thus, comparing the composition of samples returned from Ryugu and Bennu may change the way we interpret the spectral variation of C-complex asteroids.

Published
2023

36. Advancement of accuracy and frequency of the GNSS-A seafloor crustal deformation observation

Author

Yokota, Y., Ishikawa, T., Watanabe, S., Nakamura, Y., and Nagae, K.

Abstract

Although GNSS-A (Global Navigation Satellite System–Acoustic ranging combination technique) observation is a technology that measures steady or sudden seafloor crustal deformations at the centimeter level, the technical capabilities are inferior to those of terrestrial GNSS observation in terms of accuracy and frequency. Therefore, many technological developments are currently underway.We are conducting error factor analysis through simulation and experimental research in order to improve the observation accuracy and frequency of SGO-A, which is operated by the Japan Coast Guard. By investigating the effects of high-rate GNSS on GNSS-A, development of representation and modeling methods of underwater sound speed fields, and equipment and angle-dependent characteristics due to sonar characteristics, we are progressing in developing quantitative evaluation and correction methods for errors. The accuracy research of GNSS-A is closely related to the accuracy research of GNSS. In the near future, we would like to construct a unified error correction method for instruments and observation envirnments, similar to GNSS.Regarding the observation frequency, we have reached the limit of observation frequency using ships around 2020, and the development of new sea surface platforms is necessary. For example, research on autonomous buoys (wave glider), moored buoys, and flying-boat type UAVs is underway. Various marine engineering applications other than GNSS-A are underway for a research field of sea surface platforms, and this field may be further updated in the future. In this presentation, we will also discuss new sea surface platforms for GNSS-A., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023
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42. News from the GGOS DOI Working Group

Author

Elger, K., Angermann, D., Bock, Y., Bonvalot, S., Botha, R., Bradke, M., Bradshaw, E., Bruyninx, C., Carrion, D., Coetzer, G., Fridez, P., Ince, E., Lamothe, P., Navarro, V., Noll, C., Reguzzoni, M., Riley, J., Roman, D., Soudarin, L., Thaller, D., Yokota, Y., Members, A., Amponsah, G., Blevins, S., Craddock, A., Craymer, M., Michael, P., Miyahara, B., Pearlman, M., Romero, N., Schwatke, C., Sehnal, M., and Tyahla, L.

Subjects
medicine.medical_specialty, IAG, metadata, International Association for Geodesy, digital object identifier, DOI, data, Group (periodic table), Global Geodetic Observing System, geodesy, Physical therapy, medicine, geodetic data, Psychology, GGOS
Abstract

Data publications with digital object identifiers (DOI) are best practice for FAIR sharing data. Originally developed with the purpose of providing permanent access to (static) datasets described in scholarly literature, DOI today are more and more assigned to dynamic data. These DOIs are providing a citable and traceable reference of various types of sources (data, software, samples, equipment) and means of rewarding the originators and institutions. As a result of international groups, like the Coalition on Publishing Data in the Earth, Space and Environmental Sciences (COPDESS) and the Enabling FAIR Data project, data with assigned DOIs are fully citable in scholarly literature and many journals require the data underlying a publication to be available – even before accepting an article. Initial metrics for data citation allows data providers to demonstrate the value of the data collected by institutes and individual scientists.This is especially relevant for the geodesy, because, geodesy researchers are often much more involved in operational aspects and data provision than researchers in other fields might be. Therefore, compared to other scientific disciplines, geodesy researchers appear to be producing less “countable scientific” output. Consequently, geodesy data and equipment require a structured and well-documented mechanism which will enable citability, scientific recognition and reward that can be provided by assigning DOI to data and data products.To address these challenges and to identify opportunities for improved coordination and advocacy within the geodetic community, the International Association of Geodesy’s (IAG) Global Geodetic Observing System (GGOS) has established a Working Group on “Digital Object Identifiers (DOIs) for Geodetic Data Sets” in 2019. This Working Group is designated to establish best practices and advocate for the consistent implementation of DOIs across all IAG Services and in the greater geodetic community.The main objectives and activities of this working group are:(1) to identify what the community needs from consistent usage of DOIs for data in terms of being able to discover data, permanently cite data, and acknowledge the data providers (2) to develop recommendations for DOI minting strategies for different geodetic data types and granularity across IAG Services (static, dynamic, observational data, data products, combination products, networks) (3) to develop recommendations for a consistent method for data citation across all IAG Services, to support data providers, and to provide quantitative support detailing the use of geodetic datasets and other resources. (4) to develop recommendations for connecting metadata standards for data discovery (e.g. DataCite, ISO19115) with community metadata standards (GeodesyML, Station Logs) This presentation will provide an update on recent topics and first recommendations from the GGOS DOI Working Group.

Published
2022

43. Photometric behavior of Ryugu’s NIR spectral parameters

Author

Longobardo, A., primary, Palomba, E., additional, Galiano, A., additional, Dirri, F., additional, Zinzi, A., additional, D’Amore, M., additional, Domingue, D., additional, Kitazato, K., additional, Yokota, Y., additional, Schroeder, S. E., additional, Iwata, T., additional, Matsuoka, M., additional, Hiroi, T., additional, Takir, D., additional, Nakamura, T., additional, Abe, M., additional, Ohtake, M., additional, Matsuura, S., additional, Watanabe, S., additional, Yoshikawa, M., additional, Saiki, T., additional, Tanaka, S., additional, Okada, T., additional, Yamamoto, Y., additional, Takei, Y., additional, Shirai, K., additional, Hirata, N., additional, Matsumoto, K., additional, and Tsuda, Y., additional

Published
2022
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