자망의 수중 형상에 대한 음향학적 해석

Abstract

2006년 9월 9~10일 (대조기)과 9월 28~29일 (소조기)에 경남 고성군 자란만에서 무선부이식 3차원 수중위치측정시스템을 사용하여, 자망의 수중형상을 측정하였다. 이 실험에서 사용한 7개의 음향송신기 중 6개는 자망의 뜸줄에 부착하였고, 나머지 1개는 해저에 고정시켰다. 실험 결과는 다음과 같다. 1. 대조기의 자망은 서쪽으로 최대 27.0 m (22:00) 이동하였고 (4.4 cm/s, 311.9°), 동쪽으로 최대 20.6 m (04:00) 이동하였다 (3.9 cm/s, 66.5°). 자망의 뻗힌 거리 (음향송신기 P1과 P6 거리)는 최대 119.8 m (21:00)이었고 (11.6 cm/s, 321.9°), 최소 109.9 m (23:00)이었다 (16.1 cm/s, 88.5°). 2. 소조기의 자망은 동쪽으로 최대 38.0 m (20:00) 이동하였고 (9.6 cm/s, 278.2°), 서쪽으로 최대 11.0 m (12:00) 이동하였다 (1.9 cm/s, 232.1°). 자망의 뻗힌 거리는 최대 99.6 m (14:00)이었고 (12.5 cm/s, 94.7°), 최소 85.0 m (06:00)이었다 (9.0 cm/s, 265.8°). 3. 대조기에 해저로부터의 자망 높이는 최대 3.7 m (02:00)이었고 (7.4 cm/s, 151.6°), 최소 1.5 m (23:30, 05:00, 06:30)로 실험 기간동안 3차례에 걸쳐서 나타났다. 그 때의 유향 및 유속은 각각 17.9 cm/s, 85.3° (23:30), 16.1 cm/s, 249.4° (05:00), 13.7 cm/s, 291.4° (06:30)이었다. 4. 소조기에 해저로부터의 자망 높이는 최대 3.6 m (12:30)이었고 (2.1 cm/s, 242.3°), 최소 1.5 m (14:00)이었다 (12.5 cm/s, 94.7°).

An experiment to acoustically analyze the shape in the current of gill-net was conducted in Jaran Bay, Gosung, Korea on the 9th to 10th September (spring tide) and 28th to 29th September (neap tide) 2006. It was measured by a 3D underwater positioning system with a radio-acoustic linked positioning buoys. Six of 7 acoustic transmitters used in the experiment were attached on the float line of the gill-net and the other was fixed on the sea bed. The results are summarized as follows: 1. During spring tide, the maximum movement of the gill-net was 27.0 m (22:00) in the west (4.4 cm/s, 311.9°) and 20.6 m (04:00) in the east (3.9 cm/s, 66.5°). The maximum extension of the gill-net (the distance between P1 and P6) was 119.8 m (21:00, 11.6 cm/s, 321.9°) and the minimum was 109.9 m (23:00, 16.1 cm/s, 88.5°). 2. During neap tide, the maximum movement was 38.0 m (20:00) in the east (9.6 cm/s, 278.2°) and 11.0 m (12:00) in the west (1.9 cm/s, 232.1°). The maximum extension was 99.6 m (14:00, 12.5 cm/s, 94.7°) and the minimum was 85.0 m (06:00, 9.0 cm/s, 265.8°). 3. During spring tide, the maximum height of the gill-net from the sea bed was 3.7 m (02:00, 7.4 cm/s, 151.6°) and the minimum was produced the three times as 1.5 m. At that time, the current speed and direction was 17.9 cm/s and 85.3° (23:30), 16.1 cm/s and 249.4° (05:00), and 13.7 cm/s and 291.4° (06:30), respectively. 4. During neap tide, the maximum height was 3.6 m (12:30, 2.1 cm/s, 242.3°) and the minimum was 1.5 m (14:00, 12.5 cm/s, 94.7°).