Research on the laws controlling the shoreline equilibrium shape has been one important topic of studying the evolvement and stabilization of sandy coasts. After a brief review of the progress on the equilibrium shape...Research on the laws controlling the shoreline equilibrium shape has been one important topic of studying the evolvement and stabilization of sandy coasts. After a brief review of the progress on the equilibrium shape laws research, five models are introduced in detail. Advantages and disadvantages of these models are then discussed, which leads to the conclusion that the empirical formula integrating with analysis of mechanism should be the future direction of study on the headland-bay equilibrium shape laws. Finally, the importance of the study on the equilibrium shape of headland-bay in China is also discussed.展开更多
文摘为探究干散货运费市场的波动规律,以研究干散货运价指数与钢材价格联动为基础,探究大宗原材料的海运成本与产品价格之间的联动关系和联动机制.以2003—2013年波罗的海海岬型指数(Baltic Capesize Index,BCI)与国际钢材价格指数(由Commodity Research Unit研发,记为CRU指数)的周度数据作为基础,用ADF和Johansen检验法验证数据的平稳性与协整特征;在符合平稳性要求基础上,引入Granger因果检验方法,探索BCI与CRU指数之间的因果关系.通过GARCH模型,评估运输成本与产品价格之间的溢出效应及其相关性影响程度.最后,结合数据分析结果,构建大宗原材料的运输成本与原材料价格之间的联动机制.研究表明:钢材价格对铁矿石海运运费有非常重要且直接的影响,而铁矿石海运运费对钢材价格并无直接的影响;BCI与CRU指数存在显著的自相关,但是BCI更容易受到其他因素变化的干扰;BCI和CRU指数都具有显著的ARCH效应,且BCI波动本身对未来的影响是逐步衰弱的;CRU指数对BCI的影响较小且综合影响为正相关,而BCI对CRU指数的影响较大且综合影响为负相关.
基金the National Natural Science Foundation of China under the contract No. 40576041.
文摘Research on the laws controlling the shoreline equilibrium shape has been one important topic of studying the evolvement and stabilization of sandy coasts. After a brief review of the progress on the equilibrium shape laws research, five models are introduced in detail. Advantages and disadvantages of these models are then discussed, which leads to the conclusion that the empirical formula integrating with analysis of mechanism should be the future direction of study on the headland-bay equilibrium shape laws. Finally, the importance of the study on the equilibrium shape of headland-bay in China is also discussed.