http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Improvement in Bottom Detection for Hydroacoustic Assessment of Demersal Fish
Hwang, Doo Jin,Iida, Kohji,Takao, Yoshimi,Miyanohana, Yoichi,Sawada, Kouichi,Okumura, Tsuyoshi 한국수산자원학회 1998 한국수산자원학회지 Vol.1 No.1
Due to the importance of bottom detection method for defining an integration layer with the bottom as a reference basis, some theoretical elements which form bottom echoes during acoustic survey of demersal fish were considered. A stable bottom detection method based on maximum voltage difference, which was not influenced by variable levels and waveform transformation. The method has been shown to be effective using in-situ bottom echo waveforms and computer simulation data. A comparison between near-bottom SV profiles acquired in Funka Bay, Hokkaido, of Japan and the East China Sea, with the threshold method and maximum differential voltage method, shows that the SV obtained with the maximum differential voltage method is 46 dB higher than those with threshold method within 2m from the bottom.
주파수 70 kHz를 이용한 보름달물해파리의 유영 자세각과 박동에 따른 초음파산란강도
윤은아 ( Eun A Yoon ),황두진 ( Doo Jin Hwang ),( Miyuki Hirose ),( Kouichi Sawada ),( Yoshiaki Fukuda ),( Tohru Mukai ) 한국수산해양기술학회 2015 수산해양기술연구 Vol.51 No.3
Target strength (TS) information is an important parameter that estimates the detection, distribution, and abundance of Aurelia aurita. In order to investigate the biological TS of jellyfish, some factors such as size (bell diameter), tilt angle, pulsation, and symbion should be known. In the ex situ TS measurements, the tilt angles and pulsation from synchronized swimming behavior of four live A. aurita (bell diameters in the air: 54.2 ~ 94.2 mm) were measured with the acoustic data at 70 kHz. The reduced target strength (RTS) of A. aurita was found to change ranged from 13.4 ~ 16.5 dB according to the incidence angles from -30° to 24°. When the change rate of bell diameter in the water was 0.2, the TS value showed a 7.2 dB change. These results could be utilized as an important data to understand the acoustic characteristic scattering of A. aurita.