In this paper, we define the Weibull kernel and use it to nonparametric estimation of the probability density function (pdf) and the hazard rate function for independent and identically distributed (iid) data. The bia...In this paper, we define the Weibull kernel and use it to nonparametric estimation of the probability density function (pdf) and the hazard rate function for independent and identically distributed (iid) data. The bias, variance and the optimal bandwidth of the proposed estimator are investigated. Moreover, the asymptotic normality of the proposed estimator is investigated. The performance of the proposed estimator is tested using simulation study and real data.展开更多
In this paper two kernel density estimators are introduced and investigated. In order to reduce bias, we intuitively subtract an estimated bias term from ordinary kernel density estimator. The second proposed density ...In this paper two kernel density estimators are introduced and investigated. In order to reduce bias, we intuitively subtract an estimated bias term from ordinary kernel density estimator. The second proposed density estimator is a geometric extrapolation of the first bias reduced estimator. Theoretical properties such as bias, variance and mean squared error are investigated for both estimators. To observe their finite sample performance, a Monte Carlo simulation study based on small to moderately large samples is presented.展开更多
In this paper, the normal approximation rate and the random weighting approximation rate of error distribution of the kernel estimator of conditional density function f(y|x) are studied. The results may be used to...In this paper, the normal approximation rate and the random weighting approximation rate of error distribution of the kernel estimator of conditional density function f(y|x) are studied. The results may be used to construct the confidence interval of f(y|x) .展开更多
为探讨水氮(WN)交互作用对澳洲坚果光合生理效应和果实品质的影响机制,提出科学的水氮调控策略,以9年生澳洲坚果品种HAES344为试材,设置每株施氮肥0、300 g 2个氮肥水平,编号N_(0)和N_(1);不灌水,田间持水量25%~35%;适当灌水,田间持水量...为探讨水氮(WN)交互作用对澳洲坚果光合生理效应和果实品质的影响机制,提出科学的水氮调控策略,以9年生澳洲坚果品种HAES344为试材,设置每株施氮肥0、300 g 2个氮肥水平,编号N_(0)和N_(1);不灌水,田间持水量25%~35%;适当灌水,田间持水量55%~65%;正常灌水,田间持水量75%~85%3个灌溉水平,编号W_(0)、W_(1)、W_(2),组合为N_(0)W_(0)、N_(0)W_(1)、N_(0)W_(2)、N_(1)W_(0)、N_(1)W_(1)、N_(1)W_(2)等6个水氮处理,测定比较不同水氮处理的叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO_(2)浓度(Ci)、水分利用效率(WUE),脯氨酸、丙二醛、可溶性糖、淀粉含量,株产及果实品质。结果表明,水氮互作下,花期叶片Pn、Gs、Ci和WUE随水分增加呈先增加后减小变化,Tr呈递增或递减趋势;果实膨大期、果实油分积累期的Pn、Gs、Ci、Tr、WUE都呈现先增加后减少趋势。施氮处理后光合效应提升,花期Pn、Ci、Tr等光合指标受N和W影响显著,果实膨大期和果实油分积累期灌溉方式W为主要影响因子,干旱或重度水分胁迫均会显著降低Pn。适量灌溉和施氮条件下,叶片脯氨酸、丙二醛、可溶性糖、淀粉含量降低,这能减缓膜过氧化程度并调节渗透压,缓解干旱胁迫对澳洲坚果叶片产生的损害。花期和果实膨大期叶片丙二醛、可溶性糖、淀粉含量受N和W显著影响,存在显著交互作用。其中,N_(1)W_(1),即施氮肥300 g/株+适当灌水,田间持水量55%~65%处理,花期、果实膨大期和果实油分积累期光合生理效应最优,相较于其他处理表现出更强的抗环境胁迫能力,可促进澳洲坚果生长和果实发育,出仁率较高,株产、一级果仁质量、一级果仁率均最高。展开更多
文摘In this paper, we define the Weibull kernel and use it to nonparametric estimation of the probability density function (pdf) and the hazard rate function for independent and identically distributed (iid) data. The bias, variance and the optimal bandwidth of the proposed estimator are investigated. Moreover, the asymptotic normality of the proposed estimator is investigated. The performance of the proposed estimator is tested using simulation study and real data.
文摘In this paper two kernel density estimators are introduced and investigated. In order to reduce bias, we intuitively subtract an estimated bias term from ordinary kernel density estimator. The second proposed density estimator is a geometric extrapolation of the first bias reduced estimator. Theoretical properties such as bias, variance and mean squared error are investigated for both estimators. To observe their finite sample performance, a Monte Carlo simulation study based on small to moderately large samples is presented.
基金Supported by Natural Science Foundation of Beijing City and National Natural Science Foundation ofChina(2 2 30 4 1 0 0 1 30 1
文摘In this paper, the normal approximation rate and the random weighting approximation rate of error distribution of the kernel estimator of conditional density function f(y|x) are studied. The results may be used to construct the confidence interval of f(y|x) .
文摘为探讨水氮(WN)交互作用对澳洲坚果光合生理效应和果实品质的影响机制,提出科学的水氮调控策略,以9年生澳洲坚果品种HAES344为试材,设置每株施氮肥0、300 g 2个氮肥水平,编号N_(0)和N_(1);不灌水,田间持水量25%~35%;适当灌水,田间持水量55%~65%;正常灌水,田间持水量75%~85%3个灌溉水平,编号W_(0)、W_(1)、W_(2),组合为N_(0)W_(0)、N_(0)W_(1)、N_(0)W_(2)、N_(1)W_(0)、N_(1)W_(1)、N_(1)W_(2)等6个水氮处理,测定比较不同水氮处理的叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO_(2)浓度(Ci)、水分利用效率(WUE),脯氨酸、丙二醛、可溶性糖、淀粉含量,株产及果实品质。结果表明,水氮互作下,花期叶片Pn、Gs、Ci和WUE随水分增加呈先增加后减小变化,Tr呈递增或递减趋势;果实膨大期、果实油分积累期的Pn、Gs、Ci、Tr、WUE都呈现先增加后减少趋势。施氮处理后光合效应提升,花期Pn、Ci、Tr等光合指标受N和W影响显著,果实膨大期和果实油分积累期灌溉方式W为主要影响因子,干旱或重度水分胁迫均会显著降低Pn。适量灌溉和施氮条件下,叶片脯氨酸、丙二醛、可溶性糖、淀粉含量降低,这能减缓膜过氧化程度并调节渗透压,缓解干旱胁迫对澳洲坚果叶片产生的损害。花期和果实膨大期叶片丙二醛、可溶性糖、淀粉含量受N和W显著影响,存在显著交互作用。其中,N_(1)W_(1),即施氮肥300 g/株+适当灌水,田间持水量55%~65%处理,花期、果实膨大期和果实油分积累期光合生理效应最优,相较于其他处理表现出更强的抗环境胁迫能力,可促进澳洲坚果生长和果实发育,出仁率较高,株产、一级果仁质量、一级果仁率均最高。
