JOPSS - Search Results

Journal Articles

Generation method of underwater landmarks for ocean observation

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

https://doi.org/10.2299/jsp.21.15

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.

Journal Articles

Basic performance tests on vibration of support structure with flexible plates for ITER tokamak device

Takeda, Nobukazu; Kakudate, Satoshi; Shibanuma, Kiyoshi

Purazuma, Kaku Yugo Gakkai-Shi, 81(4), p.312 - 316, 2005/04

http://ci.nii.ac.jp/naid/110006281933

The vibration experiments of the support structures with flexible plates for the ITER major components such as toroidal field coil and vacuum vessel were performed using small-sized flexible plates aiming to obtain its basic mechanical characteristics such as dependence of the stiffness on the loading angle. The experimental results obtained by the hammering and frequency sweep tests were agreed each other, so that the experimental method is found to be reliable. In addition, the experimental results were compared with the analytical ones in order to estimate an adequate analytical model. As a result, the bolt connection strongly affected on the stiffness of the support structure. After studies of modeling the bolts, it is found that the analytical results modeling the bolts with finite stiffness only in the axial direction and infinite stiffness in the other directions agree well with the experimental ones. Using this model, the stiffness of the support structure for the ITER major components can be calculated precisely in order to estimate the dynamic behaviors.

JAEA Reports

Structural analysis of support structure for ITER vacuum vessel

Takeda, Nobukazu; Omori, Junji*; Nakahira, Masataka

JAERI-Tech 2004-068, 27 Pages, 2004/12

JAERI-Tech-2004-068.pdf:7.68MB

ITER vacuum vessel (VV) is a safety component confining radioactive materials such as tritium and activated dust. An independent VV support structure with multiple flexible plates located at the bottom of VV lower port is proposed. This independent concept has two advantages: (1) thermal load due to the temperature deference between VV and the lower temperature components such as TF coil becomes lower and (2) the other components such as TF coil is categorized as a non-safety component because of its independence from VV. Stress analyses have been performed to assess the integrity of the VV support structure using a precisely modeled VV structure. As a result, (1) the maximum displacement of the VV corresponding to the relative displacement between VV and TF coil is found to be 15 mm, much less than the current design value of 100 mm, and (2) the stresses of the whole VV system including VV support are estimated to be less than the allowable ones defined by ASME. Based on these assessments, the feasibility of the proposed independent VV support has been verified as a VV support.

JAEA Reports

Neutron image characteristics of imaging plates using SrBPO $_{5}$ :Eu $^{2+}$ photostimulabe phosphors

Sakasai, Kaoru; Katagiri, Masaki; Nakamura, Tatsuya

JAERI-Research 2004-019, 33 Pages, 2004/12

JAERI-Research-2004-019.pdf:7.99MB

As a new candidate for raw materials of a neutron imaging plate, characteristics of a SrBPO $_{5}$ :Eu $^{2+}$ phosphor that has boron (B) in the base matrix as a neutron converter have been investigated. The phosphor has a strong merit that it generates photostimulated luminescence of 390 nm by illumination of red laser light after neutron irradiation. The emission and excitation wavelengths were the same as those of commercially available neutron imaging plate. Therefore, the authors have fabricated neutron imaging plates by painting the phosphor on Al plates. Neutron imaging experiments using the fabricated imaging plates were carried out with a commercially available image reader. A Li block was used as a camera subject in the experiments. As a result of the experiments, it was confirmed that the neutron image was clearly obtained, though the intensity of the image was not so high. The position resolution of 0.2 mm was obtained when the readout resolution of 50 m in the reader was used.

Journal Articles

Design and structural analysis of support structure for ITER vacuum vessel

Takeda, Nobukazu; Omori, Junji*; Nakahira, Masataka; Shibanuma, Kiyoshi

Journal of Nuclear Science and Technology, 41(12), p.1280 - 1286, 2004/12

https://doi.org/10.3327/jnst.41.1280

Times Cited Count：3 Percentile：23.51(Nuclear Science & Technology)

ITER vacuum vessel (VV) is a safety component confining radioactive materials. An independent VV support structure located at the bottom of VV lower port is proposed as an alternative concept, which is deferent from the current reference, i.e., the VV support is directly connected to the toroidal coil (TF coil). This independent concept has two advantages comparing to the reference one: (1) thermal load becomes lower and (2) the TF coil is categorized as a non-safety component. Stress Analyses have been performed to assess the integrity of the VV support structure. As a result, (1) the maximum displacement of the VV corresponding to the relative displacement between VV and TF coil is found to be 15 mm, much less than the current design value of 100 mm, and (2) the stresses of the whole VV system including VV support are estimated to be less than the allowable ones defined by ASME, respectively. Based on these assessments, the feasibility of the proposed independent VV support has been verified as an alternative VV support.

Journal Articles

Design and structural analysis of support structure for ITER vacuum vessel

Takeda, Nobukazu; Omori, Junji*; Nakahira, Masataka; Shibanuma, Kiyoshi

Journal of Nuclear Science and Technology, 41(12), p.1280 - 1286, 2004/12

https://doi.org/10.1080/18811248.2004.9726357

The vibration experiments of the support structures with flexible plates for the ITER major components such as toroidal field coil and vacuum vessel were performed using small-sized flexible plates aiming to obtain its basic mechanical characteristics such as dependence of the stiffness on the loading angle. The experimental results obtained by the hammering and frequency sweep tests were agreed each other, so that the experimental method is found to be reliable. In addition, the experimental results were compared with the analytical ones in order to estimate an adequate analytical model. As a result, the bolt connection strongly affected on the stiffness of the support structure. After studies of modeling the bolts, it is found that the analytical results modeling the bolts with finite stiffness only in the axial direction and infinite stiffness in the other directions agree well with the experimental ones. Using this model, the stiffness of the support structure for the ITER major components can be calculated precisely in order to estimate the dynamic behaviors.

Journal Articles