著者
伊東 聖矢 金子 直史 鷲見 和彦
出版者
公益社団法人 精密工学会
雑誌
精密工学会誌 (ISSN:09120289)
巻号頁・発行日
vol.86, no.12, pp.1042-1050, 2020-12-05 (Released:2020-12-05)
参考文献数
35

Recent learning-based multi-view stereo (MVS) approaches have shown excellent performance. These approaches typically train a deep neural network to estimate dense depth maps from multiple images. However, most of these approaches require large-scale dense depth maps as the supervisory signals during training. This paper proposes a self-supervised learning framework for MVS, which learns to estimate dense depth maps from multiple images without dense depth supervision. Taking an arbitrary number of images as input, we produce sparse depth maps using structure from motion and use it as self-supervision. We apply reconstruction and smoothness losses to regions where there is no sparse depth. For stable training, we introduce a pseudo-depth loss, which is the difference between depth maps estimated by the network with the current and past parameters. Experimental results on multiple datasets demonstrate the effectiveness of our self-supervised learning framework.
著者
東 聖 伊藤 大介 石田 貴仁 岩田 明彦 菅原 賢悟 森本 茂雄
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.139, no.5, pp.495-502, 2019-05-01 (Released:2019-05-01)
参考文献数
15
被引用文献数
2

This paper proposes countermeasures to reduce radiated AM radio frequency noise caused by the VVVF (variable-voltage/variable-frequency) inverter system incorporated with an electric railway car. First, the common-mode current flowing through a cooling fin earth line is studied, and the connection change of the line shows good attenuation of the 1.26MHz resonance component. Second, the common-mode current flowing though the motor earth line with a capacitor is focused upon, and the modified connections of the line to the outside of the input common-mode core achieves fine noise reduction in the range from 500kHz to 1.5MHz. In such cases, the existing input common-mode core is utilized to establish the impedance, which is efficient in both the noise reduction and the countermeasure cost reduction. Finally, a current simulation model which is paid attention to the AM radio frequency range is examined with the measured impedance data of the VVVF inverter system. The currents flowing thorough the cooling fin earth line and the motor earth line is simulated, and these simulated currents show good agreement with the measured one.