Robust regression function estimation

A robust estimator of the regression function is proposed combining kernel methods as introduced for density estimation and robust location estimation techniques. Weak and strong consistency and asymptotic normality are shown under mild conditions on the kernel sequence. The asymptotic variance is a product from a factor depending only on the kernel and a factor similar to the asymptotic variance in robust estimation of location. The estimation is minimax robust in the sense of Huber (1964). Robust estimation of a location parameter. Ann. Math. Statist.33 73–101.     

Fuzzy preference orderings in group decision making

In this paper, some use of fuzzy preference orderings in group decision making is discussed. First, fuzzy preference orderings are defined as fuzzy binary relations satisfying reciprocity and max-min transitivity. Then, particularly in the case where individual preferences are represented by utility functions (utility values), group fuzzy preference orderings of which fuzziness is caused by differences or diversity of individual opinions are defined. Those orderings might be useful for proceeding the group decision making process smoothly, in the same manner as the extended contributive rule method.     

Assessment of the impact of a phosphatic fertilizer plant on the adjacent environment using fuzzy logic

The impact of a phosphatic fertilizer plant on the adjacent environment was examined. Selected rare earth elements, heavy metals and metalloids were determined in substrates and products, waste by-product, and grass and soil samples. Concentration gradients of elements in grass and soil samples along the southerly and easterly directions were examined and compared with the content of interior soil and grass samples, substrates, and products. Results were compared with available data on soil permissible element concentration levels. Two fuzzy principal component analysis (FPCA) methods for robust estimation of principal components were applied and compared with classical PCA. The efficiency of the new algorithms is illustrated. The investigation explored the impact of the plant on the adjacent environment. The most reliable results, in good agreement with types of samples, were produced using the FPCA-O algorithm     

小波变换结合多维偏最小二乘方法用于近红外光谱定量分析

将小波变换和多维偏最小二乘法相结合用于近红外光谱定量校正模型的建立。首先将原始光谱进行小波变换分解，得到系列小波细节系数，通过选取一组受外界因素少、信息强的小波系数组成三维光谱阵，然后再采用多维偏最小二乘法建立校正模型。实验结果表明，该方法所建近红外校正模捌的预测能力更强，并更具稳健性。     

基于特征点的整数小波目标跟踪方法的研究

基于提升方法的整数小波变换的诸多优点,以Harr整数小波变换为例,提出了动态目标跟踪算法。对标准图像进行整数Harr小波变换,并将提升项取整,对提升项的参数用一定数量训练图像进行学习。选取在训练参数平方和为最小意义上的、使整数小波变换后的图像高频部分具有较大值的点作为特征点。对包含有目标的参考图像进行整数小波变换,选择高频分量具有较大值的点,利用训练过的提升项参数使目标和基准图像配准。由于算法采用整数小波变换,使提取具有较好的鲁棒性,从而实现目标发生旋转、平移及尺度变化等的跟踪过程。仿真实验表明,该方法能对动态运动目标进行跟踪。     

Robust fuzzy control for chaotic dynamics in Lorenz systems with uncertainties

This paper deals with the robust fuzzy control for chaotic systems in the presence of parametric uncertainties. An uncertain Takagi--Sugeno fuzzy model for a Lorenz chaotic system is first constructed. Then a robust fuzzy state feedback control scheme ensures the control for stable operations under bounded parametric uncertainties. For a chaotic system with known uncertainty bounds, a robust fuzzy regulator is designed by choosing the control parameters satisfying the linear matrix inequality. To verify the validity and effectiveness of the proposed controller design method, an analysis technique is suggested and applied to the control of an uncertain Lorenz chaotic system.     

一种改进的粒子滤波算法在SINS初始对准中的应用

在实际工程环境中,针对捷联惯导系统(SINS)大失准角初始对准中噪声统计特性未知的问题,设计了一种基于H?滤波算法的鲁棒无迹粒子滤波算法(RUPF)。通过将无迹卡尔曼滤波算法(UKF)和鲁棒环节引入到粒子滤波(PF)的重要性密度函数中,得到了RUPF算法,提高了算法的鲁棒性。通过半物理实验,将RUPF算法与无迹粒子滤波算法(UPF)在SINS静基座大失准角对准中的性能进行了比较,在不同实验条件下,航向失准角精度至少提高了40%,对准精度优于0.05°,对准时间减少了约50 s。实验结果表明,RUPF算法可以以较高的精度和较快的速度完成大失准角初始对准,且对准精度和对准速度均优于UPF算法。     

卫星分群的抗差Kalman滤波在GPS/BDS融合精密单点定位中的应用

抗差Kalman滤波是控制GNSS动态导航定位中观测异常的有效算法,当应用到GPS/BDS实时动态精密单点定位(Precise Point Positioning,PPP)时,会出现某些历元定位精度甚至不如单一系统定位精度高,这主要是因为同一接收机接收的不同种类卫星观测量的随机特性不同,使得观测量验后残差的分布特性不一致,抗差估计时随机特性不同的观测量验后残差互比,反而对某一系统优质数据也进行了降权,导致定位结果出现偏差,减弱了GPS/BDS融合精密单点定位的优势。针对这一问题,提出了卫星分群的抗差Kalman滤波算法,并应用到GPS/BDS融合精密单点定位中,算法的核心是在每一历元观测数据质量控制时根据卫星类型分类构建方差膨胀因子,给出了算法的实施步骤,最后通过MGEX实测数据进行了验证,结果表明算法应用到GPS/BDS融合精密单点定位中,相较传统的抗差Kalman滤波算法在东、北、天三个方向分别提高了34.6%、33.3%、31.0%,同时表明该算法提高了GPS/BDS融合精密单点定位的可靠性。     

橡胶拉伸强度能力验证计划和统计分析

采用稳健统计技术对全国84家实验室橡胶拉伸强度能力验证结果进行统计分析,结果显示全部满意的实验室78家,结果可疑的实验室有6家,并对实验室结果出现可疑的原因进行了分析。     

The role of nickel(II) on the homochirality of amino acids in living systems

<正>The origin of homochirality in living organisms is controversial,stands out of being particularly important and a question which is still not satisfactorily answered.A mental picture of sequence of events that is thought to have preceded the existence of chirality in molecules is described.A chemical model to mimic the original abiotic conditions in an attempt to explain the preference of homochirality in living systems was tried.The effect which might have influenced this preference is presented.The surprising and unexpected results are indeed interesting,significant,repeatable and indicate that complexing alanine with nickel(Ⅱ) ion alters the racemization rates of D and L isomers of the amino acid.However,why this difference happens is unclear and is difficult to explain.