Prediction of Design Wind Speeds by Extreme Value EstimationProcedures

9411642 Corotis支持继续研究用于预测设计风速的极值估计程序。在第一阶段，对几种可用的技术进行了测试，并与一些优于其他方法的方法进行了比较，例如，对于来自Gumbel和反向威布尔分布的数据，阈值方法比时代方法表现得更好，但对于来自正态分布的数据，情况正好相反。在研究的第二阶段，将使用从最大每日最快英里速度中获取的数据的统计分析和基于这些分析得出的概率模型的蒙特卡罗模拟。本工作的目标是：1)对累积均值超越和de Haan-Dekkers-Einmahl估计方法的性能进行排序；2)考虑季节性影响；3)验证反威布尔分布是否比冈贝尔分布更适合极端速度数据集；4)根据短记录估计极端风“超过阈值峰值”的置信水平。来自美国气象站的长期风速数据将用于比较时代和阈值方法，并改进确定设计风速的程序。这项工作的结果将提高在极端大风地区建造的结构的生存能力，从而提高当地人口的安全。＊＊＊

9411642 Corotis Support is provided to continue research on extreme value estimation procedures for the prediction of design wind speeds. During the first phase several available techniques were tested and compared with some methods performing better than others, e.g., for data from Gumbel and reverse Weibull distributions the threshold approach performed better than the epochal approach but the reverse was true for data from a normal distribution. During the second phase of the research statistical analyses of data taken from maximum daily fastest mile speeds and Monte Carlo simulations based on the probabilistic models derived from these analyses will be used. The objectives of the work are: 1) to rank the performances of the Cumulative Mean Excedance and the de Haan-Dekkers-Einmahl estimation methods; 2) to account for the seasonality effects; 3) to verify whether more extreme speed data sets are in fact better fitted by reverse Weibull than by Gumbel distributions; and 4) to estimate confidence levels for "peaks over threshold" estimates of extreme winds based on short records. Long term wind speed data from United States weather stations will be used to compare epochal and threshold methods and to refine procedures for determining design wind speeds. The results from this work will improve the survivability of structures built in extreme wind areas and thus the safety of local population. ***