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Sato, Masayuki*; Muraoka, Koji*; Hozumi, Koki*; Sanada, Yukihisa; Yamada, Tsutomu*; Torii, Tatsuo
Nihon Koku Uchu Gakkai Rombunshu (Internet), 65(2), p.54 - 63, 2017/02
This paper is concerned with the design problem of preview altitude controller for Unmanned Airplane for Radiation Monitoring System (UARMS) to improve its control performance. UARMS has been developed for radiation monitoring around Fukushima Daiichi Nuclear Power Plant which spread radiation contaminant due to the huge tsunamis caused by the Great East Japan Earthquake. The monitoring area contains flat as well as mountain areas. The basic flight controller has been confirmed to have satisfactory performance with respect to altitude holding; however, the control performance for variable altitude commands is not sufficient for practical use in mountain areas. We therefore design preview altitude controller with only proportional gains by considering the practicality and the strong requirement of safety for UARMS. Control performance of the designed preview controller was evaluated by flight tests conducted around Fukushima Sky Park.
Mirabueno, M. H. T.*; Torii, Masayuki*; Laguerta, E. P.*; Delos Reyes, P. J.*; Fujiki, Toshiyuki*; Bariso, E. B.*; Okuno, Mitsuru*; Nakamura, Toshio*; Danhara, Toru*; Kokubu, Yoko; et al.
Chigaku Zasshi, 123(5), p.751 - 760, 2014/10
Core drilling at site IRBH-2 within Irosin caldera, southern Luzon, reached 50 m. Systematic logging and documentation were done to describe the sediments. AMS 
C dates were obtained for plant fragments from the peaty layers. Lahars and fluvial deposits were the predominant deposits in the core sequence. The upper 12 m was comprised mostly by andesitic fluvial and minor lahars. Eight fallouts were intercalated with reworked sediments from depth interval of 20 to 50 m. The refractive index measurement of analyzed samples indicated that post-caldera eruptions generated andesite, dacite and minor rhyolite. The similarity in petrographic characteristics between the rhyolite fallout and the Irosin ignimbrite indicates that small-scale eruptions involving magma from the caldera event occurred during post-caldera stage.Young radiocarbon dates obtained from the peaty layers shows that volcaniclastic deposits in the upper levels were likely derived from the eruptions of Bulusan volcano.
Hirayama, Tomoko*; Torii, Takashi*; Konishi, Yohei*; Maeda, Masayuki*; Matsuoka, Takashi*; Inoue, Kazuko*; Hino, Masahiro*; Yamazaki, Dai; Takeda, Masayasu
Nihon Kikai Gakkai Rombunshu, C, 77(779), p.2884 - 2893, 2011/07
Nio, Daisuke; Ikekame, Yoshinori; Suwa, Masayuki; Isaka, Koji; Ouchi, Satoshi; Mineshima, Hiromi; Motohashi, Jun; Torii, Yoshiya; Kinase, Masami; Murayama, Yoji
no journal, ,
no abstracts in English
Okuno, Mitsuru*; Wada, Keiji*; Torii, Masayuki*; Danhara, Toru*; Nakamura, Toshio*; Kokubu, Yoko; Gualtieri, L.*; Brenn, S.*
no journal, ,
Adak Island, a member of the Andreanof Islands in the Aleutian Islands, Alaska is covered with Holocene sequences of soil-tephra complexes. Tephra layers are useful for establishing a chronographic framework on the island. Black (1976) described the three conspicuous tephra deposits (Main, Intermediate and Sandwich in ascending order). In order to re-evaluate the chronological framework, we conducted AMS radiocarbon dating and petrographic analysis on cored peat deposits collected from near Haven Lake. Charcoal fragments collected from around Three Arm Bay, southwestern area, are also dated. This poster presents petrography and radiocarbon dates. Based on our results, eruption ages of the Main, Intermediate, Sandwich, YBO and Forty Yeartephra were dated to approximately 9.5, 7.2, 4.7, 3.6 and 0.4 cal ka BP, respectively.
Torii, Tatsuo; Sanada, Yukihisa; Yamada, Tsutomu; Orita, Tadashi; Muraoka, Koji*; Sato, Masayuki*; Watanabe, Akira*; Kume, Kyo*; Hasegawa, Takashi*; Sugita, Takeshi*
no journal, ,
Energetic radiation caused by thunderstorm activity is observed at various places, such as the ground, high mountain areas, and artificial satellites. In order to investigate the radiation source and its energy distribution, we measured energetic radiation by a sounding balloon, an airplane, and the ground observation. On the measurement inside the thundercloud, we conducted a sounding observation using a radiosonde mounted two GM tubes (for 
-rays, and for 
/-rays), in addition to meteorological instruments. The balloon passed through a region of strong echoes in a thundercloud shown by radar image, at which time an increase in counting rate of the GM tube about 2 orders of magnitude occurred at the altitude from 5 km to 7.5 km. Furthermore, the counting rate of 2 GM tubes indicated the tendency different depending on movement of a balloon. This result suggests that the ratio for the -rays (energetic photons) of the beta-rays (energetic electrons) varies according to the place in the thundercloud. Then, we measured the variation of the energetic radiation from the top of the thundercloud using an airplane. At this time, we used two NaI detectors different in the size. We performed the radiation measurement by flying around the thunderclouds at 12 - 14 km in height by the observation in the summer. Moreover, in the winter season, we flew 5 - 6 km in height and measured the radiation around the thunderclouds. Furthermore, we carried out a ground observation of the energetic rays during winter thunderstorm at a coastal area facing the Sea of Japan. Two types of the energetic radiation have been observed at this time. We report the outline of these measurements and analysis in the session of the JpGU meeting.
