著者
Masato Kawaguchi Hideyuki Kato
出版者
The Institute of Electronics, Information and Communication Engineers
雑誌
Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)
巻号頁・発行日
vol.14, no.3, pp.590-608, 2023 (Released:2023-07-01)
参考文献数
32

Some studies started analyzing time series via complex networks in the noughties. A study reported that time series, which were transformed into networks via recurrence plots (RPs), especially k-nearest neighbor RP, exhibited superfamily phenomena resulting from the network motif analysis. However, it is not hard to imagine that the transformation properties drastically change the results of the motif analysis. In this study, we examine that by introducing another type of RP.As a result, the RP employed in this study works better for the superfamily phenomena among the time series than the previously used RP.
著者
Tomoyuki NAKAJO Shusaku YAMAURA Fumiki ONOMA Mayuko SHIBAYAMA Takashi AOYAMA Yoshinobu KATO Yasutake ITO Hideyuki KATO
出版者
THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
雑誌
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN (ISSN:18840485)
巻号頁・発行日
vol.19, no.6, pp.845-854, 2021 (Released:2021-11-04)
参考文献数
32

In recent years, the movement to re-recognize starry sky as a regional resource and to utilize it as regional added value attracts many people. At the same time, however, the increase in the brightness of nighttime lighting due to the spread of LEDs etc. causes the night sky to gradually become brighter, and the situation in which the value of the starry sky is lost is also progressing. In order to protect the value of the starry sky, it is important to quantify the effects of nighttime lighting on the night sky brightness and to provide basic data useful for discussion on the balance between light pollution control and citizen life. From this point of view, we are promoting a project for protecting the starry sky by combining observation of nighttime lighting from space with nano-satellite and night sky brightness observation on the ground.