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201.
GRAN NILSSON 《地理学报(英文版)》1991,(6)
Comparison of methods is a technique often used for investigation of systematic errors of measurementmethods.As concerns the design and analysis of such comparisons,much variety of opinion and practiceexists.In one approach a few specimens are measured several times by different operators in differentlaboratories(reproducibility conditions)and in another approach several specimens are measured on oneor a few occasions by one operator in the same laboratory(repeatability conditions).In this paper amodel for the error structure of measurements is formulated and it is emphasized that one has todistinguish between two types of systematic errors:the first type depends only on the level of themeasured quantity and the second type is specific for the separate specimens.On the basis of this modelthe information which can be obtained from the different designs of method comparisons is discussed.A new approach for the analysis of method comparisons with many specimens is also proposed. 相似文献
202.
腾冲火山区地表垂直形变分析 总被引:11,自引:3,他引:8
对腾冲火山区1998~2000年的3期垂直形变资料进行了分析,进而利用相关资料得出与计算有关的参数,再用多元Mogi模型反演了岩浆房的位置和大小,所得出的结果与地震层析反演结果基本相似。分析反演结果,认为火山区可能存在多个岩浆房,并有岩脉相通。 相似文献
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The Meixner functions are utilized to relate the effective rainfall, the direct runoff and the unit hydrograph through linkage equations. The linkage equations are then employed to derive the unit hydrograph for given rainfall-runoff data on a small agricultural watershed. These functions are tested with regard to their ability to reproduce and predict the direct runoff hydrograph. The Meixner functions are found to be an effective analytical tool for hydrograph synthesis. Further, they compare well with the least squares and linear programming methods of the unit hydrograph derivation. 相似文献
205.
Neil S. Mancktelow 《Mathematical Geology》1981,13(6):507-521
Given a set of nondirectional orientation data (fold axes, lineations, dip and dip direction of bedding, universal stage readings of crystallographic axes, etc.),the best-fit line (point maximum),plane (great circle),or cone (small circle)can be determined by minimizing the sum of the squares of the angular residuals using a simplex convergence technique. Stereoplots of the angular deviation over the complete lower hemisphere for these distributions may also be generated when consideration of the constraint on the best-fit position is important; for example in comparing different data sets of the same structural element. The routines are available as a FORTRAN coded computer program. 相似文献
206.
ZHUXiao-hua CAIYun-long 《中国地理科学(英文版)》2004,14(1):9-14
MANDELBROT enunciated the uncertainty of the length of a coastline in his paper “How long is the coastline of Britain?” published in Science in 1967. The fractal concept was presented for the first time in that paper and has been applied to many fields ever since. Although fractal dimensions of lots of phenomena were calculated by the box-counting method, the quantitative influence of series of square grids on them is ignored. The issue is systematically discussed as a case study of the mountains of China‘s Mainland in this paper. And some significant conclusions are drawn as follows: 1) Although the fractal character objectively exists in the mountains of China‘s Mainland, and it does not vary with the changes of series of square grids, the fractal dimensions of the mountains of China‘s Mainland are different with these changes. 2) The fractal dimensions of the mountains of China‘s Mainlandvary with the average lengths of sides of series of square grids. The fractal dimension of the mountains of China‘s Mainland is the function of the average length of side of square grid. They conform to the formula D=f(r) (where D is the fractal dimension, and r is the average length of side of square grid). 3) Different dots of data collection can affect the fractal dimension of the mountains of China‘s Mainland. 4) The same range of length of side of square grid and dots of data collection can ensure the comparison of fractal dimensions of the mountains of China‘ s Mainland. The research is helpful to get the more understanding of fractal and fractal dimension, and ensure that the fractal studies would be scientific. 相似文献
207.
抗差估计中几种选权迭代法常数选取的探讨 总被引:9,自引:0,他引:9
常规抗差估计中采用选权迭代法时常数的取值是否合理直接关系到平差过程能否顺利进行和平差结果的优劣,本文通过对目前几种选权迭代法中常数的选取进行研究;得出:常数按K1=m ax(|(v1-l1)|)、C=m ax(|(vi-li)|)取值时,能有效解决常规取值方法(K1=3.0~8.0或K1=3.0~6.0,C=8)在粗差较大时出现秩亏、法方程系数矩阵奇异的现象,导致平差不能进行或者平差结果出现严重扭曲的问题,同时本文论述了在确保有解的情况下得到最优解的处理方法。 相似文献
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