Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Oto, Tsutomu; Asano, Norikazu; Kawamata, Takanori; Yanai, Tomohiro; Nishimura, Arashi; Araki, Daisuke; Otsuka, Kaoru; Takabe, Yugo; Otsuka, Noriaki; Kojima, Keidai; et al.
JAEA-Review 2020-018, 66 Pages, 2020/11
JAEA-Review-2020-018.pdf:8.87MB
A collapse event of the cooling tower of secondary cooling system in the JMTR (Japan Materials Testing Reactor) was caused by the strong wind of Typhoon No.15 on September 9, 2019. The cause of the collapse of the cooling tower was investigated and analyzed. As the result, it was identified that four causes occurred in combination. Thus, the soundness of the cooling tower of Utility Cooling Loop (UCL cooling tower), which is a wooden cooling tower installed at the same period as the cooling tower of secondary cooling system, was investigated. The items of soundness survey are to grasp the operation conditions of the UCL cooling tower, to confirm the degradation of structural materials, the inspection items and inspection status of the UCL cooling tower, and to investigate the past meteorological data. As the results of soundness survey of the UCL cooling tower, the improvement of inspection items of the UCL cooling tower was carried out and the replacement and repair of the structural materials of the UCL cooling tower were planned for safe maintenance and management of this facility. And the renewal plan of new cooling tower was created to replace the existing UCL cooling tower. This report is summarized the soundness survey of the UCL cooling tower.
Takemura, Fumiaki*; Taba, Ryo*; Hirayama, Keita*; Tansuriyavong, S.*; Kawabata, Kuniaki; Sagara, Shinichi*; Ogasawara, Kei*
Artificial Life and Robotics, 22(4), p.405 - 411, 2017/12
The manta method is a survey method that divers investigate the degree of coral and whitening state while being towed to a boat. The manta method makes great physical burden. Therefore, the authors think that this task can substitute an underwater robot. This underwater robot is desirable to be able to keep altitude above the seabed. Hence, the authors have been developing the altitude (its distance above the sea floor) keeping system for an underwater robot. Visual recognition of distant underwater objects is possible in the water with high transparency, for example, in the coastal sea area of Okinawa prefecture, Japan. So, the authors have been adopting the distance measuring method using the two laser beams and a monocular camera with image processing. It realize to keep altitude of an underwater robot by using such devices. The evaluation experiments of the altitude keeping system are carried out in the pool.
Takahashi, Satoru*; Nota, Yoshiki*; Matsuda, Asahi*; Kawabata, Kuniaki; Suzuki, Tsuyoshi*; Takemura, Fumiaki*; Ogasawara, Kei*; Kaneko, Shunichi*
Journal of Signal Processing, 21(1), p.15 - 24, 2017/01
In recent years, many researchers try to observe the state of the global environment from marine information for the understanding of the global environment change. First, we introduce the recording system of underwater environment which is made by the authors. By using this system, we want to observe the change of global environment from the coral bleaching. In this paper, especially, we propose the generation method of underwater landmark which is used to measure the position of robot of oceanographic observation based on the dynamic image processing. In here, underwater landmark means the feature point in underwater image.
Taba, Ryo*; Takemura, Fumiaki*; Tansuriyavong, S.*; Kawabata, Kuniaki; Sagara, Shinichi*; Ogasawara, Kei*
Proceedings of 21st International Symposium on Artificial Life and Robotics (AROB 21st 2016) and 1st International Symposium on BioComplexity (ISBC-1) (Internet), p.395 - 399, 2016/01
Matsuda, Asahi*; Takahashi, Satoru*; Kawabata, Kuniaki; Takemura, Fumiaki*; Ogasawara, Kei*
no journal, ,
In recent years, research of bleaching of coral based on change of underwater environment is important in order to know change of global environment. Currently, investigation of underwater is conducted by the diver. Therefore, several problems such as load for the diver and restriction of search area are occurred. To solve these problems, we are developing the underwater robot for investigating of coral reef for the wide and the long time. In here, to know the current situation of coral we consider the automatic extraction method of the coral based on texture analysis from image obtained by monitoring.
Hirayama, Keita*; Takemura, Fumiaki*; Kawabata, Kuniaki; Sagara, Shinichi*; Ogasawara, Kei*
no journal, ,
This paper discussed about the study and development of a towed underwater robot. We described about the required specifications for designing a robot prototype.
Taba, Ryo*; Hirayama, Keita*; Takemura, Fumiaki*; Tansuriyavong, S.*; Kawabata, Kuniaki; Sagara, Shinichi*; Ogasawara, Kei*
no journal, ,
This paper proposed an observation altitude maintenance method with a monocular camera for realizing Manta method-like observation. We developed a test platform and attempted the basic experiments.
Takemura, Fumiaki*; Hirayama, Keita*; Kawabata, Kuniaki; Sagara, Shinichi*; Ogasawara, Kei*
no journal, ,
This paper reported that the development of an underwater robot for coral reef inspection and also basic experiments with the prototype.
Matsuda, Asahi*; Okuda, Yudai*; Takahashi, Satoru*; Kawabata, Kuniaki; Ogasawara, Kei*
no journal, ,
Research of monitoring of corals plays an important role in observing the natural environment on a global scale. Identifying and detecting corals amongst other objects, including marine organisms, from an image taken undersea is a difficult task. Moreover, there are many types of corals and they cannot be easily categorized automatically. Currently, texture analysis is being pursued that solves the problem of detecting and recognizing corals from pictures taken undersea; Haralick 14 conditional equations are used to calculate the texture characteristics information based on the gray level co-occurrence matrix of 256 gradations and also to perform liner discrimination analysis on the characteristics information. In this paper, we propose one algorithm of texture analysis for discrimination of undersea objects, in order to detect the corals.
Ozeki, Ryutaro*; Suzuki, Tsuyoshi*; Sawai, Kei*; Takemura, Fumiaki*; Kawabata, Kuniaki; Yamashiro, Hideyuki*; Ogasawara, Kei*
no journal, ,
This article describes our latest stationary underwater sensor node configuration that is used to construct an underwater monitoring sensor network (UMSN) to support the coral ecological system survey activities, and also describes about study of the required functions of a data browsing system to monitor information of underwater environmental conditions gathered by UMSN.
Hirayama, Keita*; Taba, Ryo*; Takemura, Fumiaki*; Kawabata, Kuniaki; Sagara, Shinichi*; Ogasawara, Kei*
no journal, ,
We have been studying and developing an underwater robot for coral reef conservation. In this research, we propose a towed robot using flap device for underwater survey. This underwater robot is developed for two purposes. The first purpose of this underwater robot is reducing the physical load on the research diver. The Seconds purpose of this underwater robot is to investigate underwater of improving efficiency. We designed with towed underwater robot and umbilical cable. The robot consist of three parts, two pressure vessels, and a flap device. The umbilical cable using PLC (Power Line Communication). Preliminary experiments indicate that the towed underwater robot have basic performance.
Taba, Ryo*; Hirayama, Keita*; Takemura, Fumiaki*; Tansuriyavong, S.*; Kawabata, Kuniaki; Sagara, Shinichi*; Ogasawara, Kei*
no journal, ,
Distribution map of the degree of coral has been created by Manta method to use coral conservation activities. The manta method is a survey method that divers investigate the degree of coral and whitening state while being towed to a boat. But the manta method makes great physical burden also underwater robot can substitute, and desirable underwater robot that can maintain an altitude between underwater robot and seabed. Therefore, we have developed the altitude maintenance system for underwater robot for the purpose of investigate by Manta method is described in this paper. The distance measuring method using the laser beams and a monocular camera with image processing is adopted reason that waters inhabiting coral is high transparency. The evaluation experiments in the pool with the system and underwater robots were confirmed to have sufficient accuracy for the assumed survey mission.
Suzuki, Tsuyoshi*; Ozeki, Ryutaro*; Sawai, Kei*; Yamashiro, Hideyuki*; Takemura, Fumiaki*; Kawabata, Kuniaki; Takahashi, Satoru*; Sagara, Shinichi*; Ogasawara, Kei*
no journal, ,
In the current study, we developed an underwater monitoring sensor network system to support the observational activities to maintain the coral reef environment. This paper describes the measurement method to detect the growth area of the coral for a quantitative evaluation of the coral condition change using fluorescence coral image by capturing the underwater monitoring sensor network.
Kitamasu, Ryo*; Takahashi, Satoru*; Kawabata, Kuniaki; Ogasawara, Kei*
no journal, ,
Research of monitoring of corals plays an important role in observing the natural environment on a global scale. Identifying and detecting corals amongst other objects, including marine organisms, from an image taken undersea is a difficult task. Moreover, there are many types of corals and they cannot be easily categorized automatically. Currently, texture analysis is being pursued that solves the problem of detecting and recognizing corals from pictures taken undersea; Haralick 14 conditional equations are used to calculate the texture characteristics information based on the gray levelco-occurrence matrix of 256 gradations and also to perform liner discrimination analysis on the characteristics information. In this paper, we propose one algorithm of texture analysis for discrimination of undersea objects, in order to detect the corals.
