测量平差模型的抗差最小二乘解及影响函数

抗差Ｍ估计是使用最广泛、计算较简明的抗差估计法。基于多维Ｍ估计原理，本文建立了经典测量平差函数模型的抗差解，并推导出相应的误差影响函数；为了使抗差估计适于不同类型以及不同先验精度的各类观测值的混合平差，将使用等价权原理构造抗差最小二乘解式。     

BAYES方差分量估计在虚拟权平差中的应用

本文把近似Bayes方基分量估计公式应用于矿区扩建网的虚拟权平差中，解决了具体计算中的一些实际问题，最后，通过一矿区扩建网平差实例验证了该方法的可行性．     

对建立遥感估产模式的几点初步认识

本文从分析遥感光谱参数的生物学意义着手，论证了正确建立遥感估产模型的可能途径。对几种有代表性的遥感估产模型作了分析，作者认为把可见光、近红外波段的遥感信息与热红外信息有机结合是解决遥感估产模型的最佳方案。对ＮＯＡＡ－ＡＶＨＲＲ的第１通道与第２通道光谱数值进行非朗伯体特性的纠正是必要的。遥感估产模型不仅可以使估产的空间尺度大大缩小而且参数数目亦可大大减小，更有利于实际运行。     

则木河与小江断裂交汇区地震危险性的概率预测

本文针对则木河与小江断裂交汇区的强震趋势问题，给出了地震危险性的分析方法，结果及问题讨论。     

Evaluation and comparison of spatial interpolators II

The performance of several variations on ordinary kriging and inverse distance estimators is evaluated. Mean squared errors (MSE) were calculated for estimates made on multiple resamplings from five exhaustive data bases representing two distinctly different types of estimation problem. Ordinary kriging, when performed with variograms estimated from the sample data, was more robust than inverse-distance methods to the type of estimation problem, and to the choice of estimation parameters such as number of neighbors.Notice: Although the research described in this article has been funded in part by the United States Environmental Protection Agency through Cooperative Agreement CR818526 to the Harry Reid Center for Environmental Studies, University of Nevada-Las Vegas, it has not been subjected to Agency review. Therefore it does not necessarily reflect the views of the Agency. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.     

Fitting variogram models by weighted least squares

The method of weighted least squares is shown to be an appropriate way of fitting variogram models. The weighting scheme automatically gives most weight to early lags and down-weights those lags with a small number of pairs. Although weights are derived assuming the data are Gaussian (normal), they are shown to be still appropriate in the setting where data are a (smooth) transform of the Gaussian case. The method of (iterated) generalized least squares, which takes into account correlation between variogram estimators at different lags, offer more statistical efficiency at the price of more complexity. Weighted least squares for the robust estimator, based on square root differences, is less of a compromise.     

Emission spectrographic estimation of gold

A procedure for estimating minute quantities (parts per billion) of gold is described, based on dissolution of the sample in aqua regia, adsorption on activated charcoal, arcing of the charcoal ash, and measurement of the intensity of the emitted spectra.     

水准测量往返测较差方差之估计

现有文献中以水准测量往返测较差为统计量估计较差方差已提出许多观点和公式,但对于较差误差模型既没有回答其正确性,也缺乏严密可行的参数估计方法。本文将方差分量的最小范数二次无偏估计(MINQUE)法用于较差方差估计,并提出了以近代回归分析原理为基础的较差误差模型统计检验与比较选择的基本方法。这些估计、分析方法既简单易行又严密合理。最后通过对部分一等水准实测数据试算分析,也初步证实了它们的实际效益。     

A Preliminary Study on the Probabilistic Estimation of Deaths from Future Earthquakes in North China

During the period from 1800 to 1989,the degree of fatalities(?from earthquakes in North China(Lat.34.0°-42.0°N,Long.107.5°-125.0°E)varied exponentially with the frequency of earthquake events(N),namely:N=37.71 exp(-0.72?(E-logD,D:deaths).For the periods from 1988 to 1998 and from 1999 to 2009,the probabilities for earthquakes to cause one thousand or more deaths in North China are estimated to be 0.37 and 0.50,respectively,by using the Gumbel's extreme value theory.     

Exploratory spectral analysis of hydrological times series

Current methods of estimation of the univariate spectral density are reviewed and some improvements are made. It is suggested that spectral analysis may perhaps be best thought of as another exploratory data analysis (EDA) tool which complements, rather than competes with, the popular ARMA model building approach. A new diagnostic check for ARMA model adequacy based on the nonparametric spectral density is introduced. Additionally, two new algorithms for fast computation of the autoregressive spectral density function are presented. For improving interpretation of results, a new style of plotting the spectral density function is suggested. Exploratory spectral analyses of a number of hydrological time series are performed and some interesting periodicities are suggested for further investigation. The application of spectral analysis to determine the possible existence of long memory in natural time series is discussed with respect to long riverflow, treering and mud varve series. Moreover, a comparison of the estimated spectral densities suggests the ARMA models fitted previously to these datasets adequately describe the low frequency component. Finally, the software and data used in this paper are available by anonymous ftp from fisher.stats.uwo.ca.