A Study of Safety on, Fishing Boats for Scallop Hanging Type Culture in Mooring at Trunk Line : A Method to Express the Nonlinear Response System

Abstract

In general, rolling motion of small fishing boats shows nonlinear response relation to waves, because small fishing boats have characteristic shapes, such as flat bottom of boat and overhanging desk. So, we suppose that rolling motion of small fishing boats for scallop hanging type culture in mooring at trunk line also shows nonlinear response relation to waves, we confirmed it by tank tests used ship model of "MARUTOU-MARU" that has a typical ship shapes of fishing boats for scallop hanging type culture. As tank tests results, the rolling response system showed nonlinear aspect. In this paper, we tried to use a Neural Network Model as one of method to express this nonlinear rolling response system of small fishing boats. The results are obtained as follows : ・Output by Neural Network Model sufficiently correspond with experimental rolling motion, and a Neural Network Model could be used to forecast rolling motion of nonlinear response system. ・The nonlinear rolling response system in fishing operations is constructed by 4 inputs, inclination of wave, y-axis acceleration, z-axis acceleration, mooring tension and 1 output, rolling angle. ・A Neural Network Model is an effective method to express nonlinear response system, like the rolling response system of small fishing boats in fishing operations.