Stochastic wave spectra estimation (SWSE) based on response surface methodology considering uncertainty in transfer functions of a ship

In this paper, a new wave spectra estimation method is proposed in which the frequency domain wave estimation method (FDWE) is extended into a probabilistic analytical framework in order to estimate the encountered sea states involving uncertainty in transfer functions of a ship. The proposed method, named the Stochastic Wave Spectra Estimation (SWSE), makes use of an Hermite polynomial chaos expansion (PCE) to represent the uncertainty in the transfer functions and the response surfaces. The method involves a mathematical formulation where an extension of the deterministic FDWE concept to the space of random variables is made. The proposed method can accurately and easily estimate the encountered wave spectra based on ship response measurements accounting for uncertainty in the transfer functions. In this paper, numerical and experimental investigations of the proposed SWSE are made, where the uncertainties in the transfer functions of heave and pitch motions of a containership are taken into account. The validity of the SWSE is demonstrated by comparison to results of uncertainty analyses through the Monte-Carlo simulations (MCS).     

钻孔与管波相结合分析岩溶发育的方法研究

岩溶在我国发育广泛，且发育无规律性，特征极其复杂。在各类工程建设过程中，很难通过传统钻探手段查明岩溶发育情况，无法给出准确客观的岩溶发育范围。通过工程实例，综合钻孔资料与管波探测结果，将钻孔资料分析后岩溶的发育范围与钻孔资料结合管波探测成果分析后岩溶的发育范围进行对比分析，发现单一根据钻孔分析岩溶发育与钻孔结合管波分析岩溶发育两者确定的岩溶发育范围上有较大差异。通过具体分析，为岩溶发育判断提供一个新思路，进而为这类地区的相关设计、施工等提供更准确的工程地质依据。