Risk Analysis for Medium- and Small-Sized Ships' Navigation in Stormy Waves

The study of navigation safety of ships in stormy waves is always an important research subject. In order to analyze more correctly the risk degree of medium- and small-sized ships, both qualitative analysis and quantitative evaluation were applied in the study. According to the principle of selecting evaluation factors and combining with the actual situation of the medium- and small-sized ships, the risk assessment factors of the ships sailing in stormy waves were determined. Risk assessment standards were constructed innovatively. Based on the principle of constructing the factors membership degree functions and related navigation knowledge, the membership degree functions were constructed. Analysis hierarchy process (AHP) and fuzzy mathematics method were integrated to set up one comprehensive evaluation mathematics model of danger degree for the medium- and small-sized ships. The model was applied for the evaluation level of danger degree for some ships sailing in a sea voyage. The research results obtained basically agreed with the truth. Some measures are put forward to ensure the ships' navigation safety in stormy waves. The model is practical, and the research results can provide some scientific decisions and references for ship commanders.