Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Ogawa, Hiroki; Hama, Yuki*; Asamori, Koichi; Ueda, Takumi*
Butsuri Tansa, 75, p.38 - 55, 2022/00
In the magnetotelluric (MT) method, so as to identify the subsurface resistivity structure, the apparent resistivity and phase profiles are calculated by transforming time-series data into spectral data. The continuous wavelet transform (CWT) is well known as a new method of time-frequency analysis instead of the short-time Fourier transform. The CWT is superior in processing non-stationary wideband signals like the MT signal by adjusting the size of the wavelet according to the value of frequency. However, the calculation settings of the CWT, such as the type of basis function and the wavelet parameter, are often determined empirically because of the arbitrariness of the shape of the wavelet. Although there might be differences between the calculated MT responses and the true responses due to improper settings of the CWT, there are no detailed studies considering the effect of numerical errors derived from spectral transforms on MT data. In this study, focusing on the frequency band between 0.001 Hz and 1 Hz, we examined the optimum calculation settings of the CWT in processing MT data in terms of suppressing the numerical errors caused by the spectral transform of time-series data. We also show the validity of the proposed calculation settings by applying the CWT to MT survey data of different types. Superiority of the CWT with proposed settings is suggested especially when the signal-to-noise ratio of observed data is low. Consequently, the proposed calculation settings were confirmed to strike a balance between the resolutions of the time and frequency domains well and will therefore be effective in obtaining reliable MT responses.
Sakurai, Yosuke*; Sato, Hirotaka*; Adachi, Nozomu*; Morooka, Satoshi; Todaka, Yoshikazu*; Kamiyama, Takashi*
Applied Sciences (Internet), 11(11), p.5219_1 - 5219_17, 2021/06
Times Cited Count：3 Percentile：41.12(Chemistry, Multidisciplinary)Moriyama, Shinichi; Shinozaki, Shinichi
Japanese Journal of Applied Physics, Part 1, 44(8), p.6224 - 6229, 2005/08
Times Cited Count：1 Percentile：4.7(Physics, Applied)The control system of RF heating system in JT-60U has been improved with a concept of dispersion processing and featuring a real time waveform shaping method. It is proper that the brand-new, dispersion processing system has higher performance and reliability than old single processor system before modification, however it is worthy of mention that improvement on operation roll sharing, using the real time waveform shaping, has enabled more efficient and smooth operation. The typical roll sharing is that a simple rectangular waveform of the RF heating power is set by the experiment operator, and the waveform is re-shaped with the parameter set by the RF operator who knows deeply the condition of the RF system at that time. The simple and flexible composition of the new control system will also enable further improvement of hardware to enhance plasma performance that is inevitable to the devices for fusion experiment.
Sakaki, Hironao; Ito, Yuichi*; Kato, Yuko*; Miyamoto, Koji*; Kawamura, Naoki*; Nakamura, Takeshi*
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.549 - 551, 2004/08
We developed the pulse wave form recorder with the flight recorder function, last year. The recorders are scheduled to be used for the beam status monitor system in J-PARC. If the pulse number between each recorder in the system has not synchronized, each waveform data can't match in the analysis software. As a result, we'll lose the time for the analysis. In this report, the design of the device that conform to all pulse number of each recorder is described.
Kondo, Masaya; Anoda, Yoshinari
JSME International Journal, Series B, 44(4), p.688 - 694, 2001/11
no abstracts in English
Yamada, Susumu
JAERI-Data/Code 2001-024, 18 Pages, 2001/08
JAERI-Data-Code-2001-024.pdf:0.83MB
no abstracts in English
Kondo, Masaya; Anoda, Yoshinari
Emerging Technologies for Fluids, Structures and Fluid-Structure Interaction, 2001 (PVP-Vol.431), p.111 - 117, 2001/07
no abstracts in English
Yamada, Susumu; Ozawa, Kazufumi*
Proceedings of 4th International Conference on Supercomputing in Nuclear Applications (SNA 2000) (CD-ROM), 8 Pages, 2000/09
no abstracts in English
*; Tani, Keiji
Proc. on Parallel Algorithms/Architecture Synthesis, p.200 - 205, 1997/03
no abstracts in English
; Anoda, Yoshinari; Kukita, Yutaka
Nihon kikai Gakkai Dai-72-Ki Zenkoku Taikai Koen Rombunshu, Vol.II, 0, 3 Pages, 1994/00
no abstracts in English
