Probabilistic Approach to the Estimation of Seamargin

在这个项目中，被理解为设计裕度或设计余量的所谓的“海量”被研究。从设计工程学的角度对传统的海绵进行了研究，指出它不是精确的设计允许范围，提出了基于概率方法的海绵的概念。新海员的定义是主机保持规定航速的概率所允许的功率裕量。实际航道中船舶航速的降低可归结为(1)长期的“老化效应”、(2)长期的“污垢效应”和(3)短期的“天气效应”。在假设各效应是独立实现的随机变量的前提下，对各效应进行区分，在估计各效应的概率密度函数后，利用概率密度函数的卷积积分估计实际航道的航速损失概率密度函数和船速概率密度函数。估计和评估超过指定阈值设计速度的概率。

In this project, the so carred "SEAMARGIN" that has been understood as the design margin or design allowance is investigated. The conventional seamargin was studied from the viewpoint of design engineering and as pointed out that it as not the exact design allowance.A ne concept of seamargin based on the probabilistic approach is proposed. The definition of the new seamargin is the power allowance of main engine to cover the probability of keeping prescribed ship speed. The decrease of ship speed in an actual seaway is represented by the sum of speed loss classified into(1)long-term 'Aging Effect', (2)NEddle-range 'Fouling Effect' and(3)short-term 'Weather Effect'. These effects are discriminated from each other under the assumption that each effect is a random variable of realizing independently.After estimating the probability density function of each effect, the probability density function of speed loss and ship speed in an actual seaway are estimated by the convolution integral of the probability density functions. The probability exceeding the specified threshold design speed is estimated and evaluated.