The Uncertainty Research Of Design Parameters Calculating Model Under Marine Environment

The design parameters calculating model under marine environment is very important in ocean engineering and seacoast disaster prevention. Ocean engineering designation will calculate return period, seacoast disaster prevention department will establish effective early warning system, both of them need design parameters calculating model. Under International Financial Crisis, export-oriented economy suffering a serious influence, while national changing economic growth mode and emphasizing sustainable development, in view of national long-term development, ocean will be the new growth pole, while ocean engineering and seacoast engineering provide powerfully support. Selecting appropriate model is the basis of all.Usually, people select design parameters calculating models under marine environment by probability paper or curve fitting method and so on. It doesn't reduce the uncertainty of data and models, conversely, human interference add uncertainty in some degree. Especially, models, all of which have being tested by hypothesis, will get different results under the same marine measured values. It is hard to choose which one to be as the design criterion in this condition.Recently, the research of design parameters calculating model's uncertainty is mainly concentrate on distribution formal analysis and its'self-uncertainty. In fact, the whole uncertainty contains both information amount, the first kind information contains the uncertainty of how to choose the model, while this kind of uncertainty usually be neglected; the second kind information is the model's own uncertainty while fix the model. In the paper, for information entropy reflects random event uncertainty, through it as the bridge to analyze whole uncertainty, considering two kind information, analyzing model information entropy in sample data's number, degree of dispersion, model distribution forms and its parameter estimator, giving a new methods which can calculate the whole uncertainty, the research contain:(1) For the uncertainty involved in the first kind information, it mostly analyzes in sample data's quantity and its'degree of dispersion; for the uncertainty involved in the second kind information, it considers the distribution forms and its parameters estimation. A result that sample data's quantity and its'degree of dispersion are in direct proportion to information entropy is proved by theory. Some common models' self-uncertainties are calculated just by their parameters, and sampling the parameters' estimation by Monte Carlo method.(2) A new information entropy calculating formula is given to consider the double uncertainty involved in the differ information, which provides a new standard and basis for the choice between differ models and evaluation criterion. Compared with the other models, the analysis based on the series of annual maximum wave heights shows that the Max-Entropy model has the minimum uncertainty.(3) To improve the difficulty in parameter estimate of the maximum entropy model, this text proposing an improving format on the basic of moment estimation, deviating a nonlinear equations which contain mean, variance, kurtosis and skewness, making the calculation more convenient and fast.