冲击噪声环境下的测向算法大多基于分数低阶统计量,其不仅计算复杂度较高,而且对强冲击噪声的适应性也较差.通过对冲击噪声的分布特性进行研究和分析,利用其冲击成分出现概率相对较低且具有随机性的特点,提出了基于中值滤波的测向新方法...冲击噪声环境下的测向算法大多基于分数低阶统计量,其不仅计算复杂度较高,而且对强冲击噪声的适应性也较差.通过对冲击噪声的分布特性进行研究和分析,利用其冲击成分出现概率相对较低且具有随机性的特点,提出了基于中值滤波的测向新方法,并推导了冲击噪声背景测向的克拉美罗界.首先,引入中值滤波方法对阵列接收数据进行平滑处理,滤除冲击噪声,并提出了针对强冲击噪声的改进方法,然后利用传统的二阶矩方法求阵列接收数据协方差矩阵并进行波达方向(Direction Of Arrival,DOA)估计.理论分析和仿真验证结果表明:所提方法处理过程简单,对低信噪比和强冲击噪声情况下的测向性能有很大的改善和提高.展开更多
Despite widespread concerns and elevated policy debates, little is known about the Chinese public＇s perceptions of water pollution and willingness to cooperate with government policies. Based on survey data, this stu...Despite widespread concerns and elevated policy debates, little is known about the Chinese public＇s perceptions of water pollution and willingness to cooperate with government policies. Based on survey data, this study examined Lake Tai resident perception of water pollution, willingness to pay （WTP） for water quality improvements, and its influencing factors. Contingent valuation （CV） results showed that respondents would prefer to pay 141 CNY per household a year, approximately 0.70% of their annual per capita disposable income, as an environmental fee to improve water quality in Lake Yai. Aggregate WTP for all five lakeside cities of Lake Tai was estimated at about 3.8 billion CNY, without discounts, in the next ten years. WTP was found to increase with income and female respondents were willing to pay more than males. Those respondents who were dissatisfied with water quality were more likely to pay more. The usage of Lake Tai did not strongly affect WTE展开更多
In this paper, the authors prove an almost sure limit theorem for the maxima of non-stationary Caussian random fields under some mild conditions related to the covariance functions of the Gaussian fields. As the by-pr...In this paper, the authors prove an almost sure limit theorem for the maxima of non-stationary Caussian random fields under some mild conditions related to the covariance functions of the Gaussian fields. As the by-products, the authors also obtain several weak convergence results which extended the existing results.展开更多
文摘冲击噪声环境下的测向算法大多基于分数低阶统计量,其不仅计算复杂度较高,而且对强冲击噪声的适应性也较差.通过对冲击噪声的分布特性进行研究和分析,利用其冲击成分出现概率相对较低且具有随机性的特点,提出了基于中值滤波的测向新方法,并推导了冲击噪声背景测向的克拉美罗界.首先,引入中值滤波方法对阵列接收数据进行平滑处理,滤除冲击噪声,并提出了针对强冲击噪声的改进方法,然后利用传统的二阶矩方法求阵列接收数据协方差矩阵并进行波达方向(Direction Of Arrival,DOA)估计.理论分析和仿真验证结果表明:所提方法处理过程简单,对低信噪比和强冲击噪声情况下的测向性能有很大的改善和提高.
基金Project supported by the National Natural Science Foundation of China (No. 70873107)the National Basic Research Program (973) of China (No. 2005CB121104)
文摘Despite widespread concerns and elevated policy debates, little is known about the Chinese public＇s perceptions of water pollution and willingness to cooperate with government policies. Based on survey data, this study examined Lake Tai resident perception of water pollution, willingness to pay （WTP） for water quality improvements, and its influencing factors. Contingent valuation （CV） results showed that respondents would prefer to pay 141 CNY per household a year, approximately 0.70% of their annual per capita disposable income, as an environmental fee to improve water quality in Lake Yai. Aggregate WTP for all five lakeside cities of Lake Tai was estimated at about 3.8 billion CNY, without discounts, in the next ten years. WTP was found to increase with income and female respondents were willing to pay more than males. Those respondents who were dissatisfied with water quality were more likely to pay more. The usage of Lake Tai did not strongly affect WTE
基金Project supported by the National Natural Science Foundation of China(No.11071182)
文摘In this paper, the authors prove an almost sure limit theorem for the maxima of non-stationary Caussian random fields under some mild conditions related to the covariance functions of the Gaussian fields. As the by-products, the authors also obtain several weak convergence results which extended the existing results.
