This study aims to understand the opening efficiency of the finless porpoise escape guide net by the type of extension net that is the part to which the escape guide net is attached in stow net. To this end, extension nets were manufactured in full size and the net mouth area and towing tension were investigated according to the towing speed (0.2, 0.4, 0.6 and 0.8 m/s) and the type of extension net (25 mm net and raschel net) in the water tank. As a result, the net mouth area of the guide net was larger when the raschel net was used for the extension net than when the 25 mm net was used under all towing speeds. In addition, regardless of the type of extension net, the net mouth area reached about 80% of the maximum value at a towing speed of 0.4 m/s. In the field, fishing operation of stow net is performed only when the current speed is above 0.4 m/s. Therefore, the speed of 0.4 m/s was confirmed as a meaningful value to determine whether it is possible to operate. As a result of analyzing the relationship between the net mouth area of the guide net and the towing tension, it was confirmed that the difference in the net mouth area of the guide net according to the type of the extension net was due to the difference in the solidity ratio.

필자는 본 논문에서 변형이론을 바탕으로 한 K-네트이론을 발전시켜 (PIN-cycle space)이라는 새로운 개념을 제시하고자 한다. PIN-사이클 공간은 PIN들의 연쇄로 이루어진 사이클로 표상되는 공간인데, 이때 PIN은 양성 동형네트워크(Positively Isographic Network)를 말하며, K-네트의 세 가지 유형 중에 하나이다. PIN-사이클 공간에 서는 한 집합류(set class)에 속하는 모든 음고류집합(pitch-class set)들이 하나의 관계망으로 제시되어, PIN-사이클 공간을 통해서 음고류집합들 간의 관계를 한층 더 효과적으로 살펴볼 수 있다. 이러한 PIN-사이클 공간을 적용하여 달라피콜라(Luigi Dallapiccola, 1904-1975)의 성악곡 《아나크레온의 두 개의 서정시》(Due Liriche di Anacreonte, 1944-1945) 중에서 제 2곡 ‘변주’(Variazioni)를 분석하였다. 그 결과, 피아노 성부에서 순서 없이 나열된 음렬 부분 이 PIN-사이클 공간에서는 일관성 있게 배열된다는 것을 알 수 있었다.