SYMMETRIC STABLE SEQUENCES WITH MISSING OBSERVATIONS

Abstract. A procedure for evaluating optimal linear estimates of missing values in the minimum dispersion sense is proposed for stationary symmetric stable processes. Analytical expressions for the estimates are obtained for the autoregressive moving-average process and it is shown that the finite variance setting results are special cases. Cases of one and more than one missing value are considered.     

A Stability Theory in Nonlinear Programming

1　ＩｎｔｒｏｄｕｃｔｉｏｎＡｃｏｎｓｔｒａｉｎｅｄｎｏｎｌｉｎｅａｒ ｐｒｏｇｒａｍｍｉｎｇｃａｎｂｅｔｒａｎｓｆｏｒｍｅｄａｎｄｓｏｌｖｅｄｂｙＯｒｄｉｎａｒｙＤｉｆｆｅｒｅｎｔｉａｌＥ ｑｕａｔｉｏｎｓ (ＯＤＥ) [4～5] [8～ 1 2 ] .Ｔｈｉｓｐａｐｅｒｕｓｅｓａｓｔａ ｂｉｌｉｔｙｔｈｅｏｒｙｏｆＯＤＥｓｙｓｔｅｍｓｔｏａｎａｌｙｓｅｔｈｅａｓｙｍｐ ｔｏｔｉｃｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｄｉｆｆｅｒｅｎｔｉａｌｅｑｕａｔｉｏｎｓｗｈｉｃｈａｒｅｄｅｒｉｖｅｄｆｒｏｍａｇｉｖｅｎｃｏｎｓｔｒａｉ…     

双螺杆挤压机的系统模型

本文指出了双螺杆挤压机系统的影响因素,从挤压系统的目标函数出发描绘了各因素与目标函数的相互影响过程,最后建立了一种双螺杆挤压机的系统模型     

Rapid and non-destructive analysis of apricot fruit quality using FT-near-infrared spectroscopy

A non-destructive optical method based on near-infrared spectroscopy has been used for the evaluation of apricot fruit quality. Diffuse reflectance measurements (800–2500 nm), physical, physiological and biochemical measurements were performed individually on 877 apricot fruits from eight contrasted cultivars harvested at different ripening stages. Relationships between spectral wavelengths and quality attributes were evaluated by application of chemometric techniques based on partial least squares (PLS) on fruit set divided randomly into two groups: 598 fruits for calibration and 279 for validation. Good prediction performance was obtained for soluble solids and titratable acidity with correlation coefficients of 0.92 and 0.89 respectively and root mean square errors of prediction of 0.98% Brix and 3.62 meq 100 g⁻¹ FW respectively. For the other quality traits such as firmness, ethylene, individual sugars and organic acids, the prediction models were not satisfactorily accurate due to the high error of calibration and prediction.     

多元函数可微性的一个注记

给出了Henle定理的简单证明，并指出该定理在n≥3时不再成立，进而又给出了一个当n≥3时，函数z=f(x1，x2，…，xn)在点M0可微的定理及其证明。     

无效变量消除法在油菜籽芥酸近红外无损速测中的应用

探索改善油菜籽芥酸近红外预测模型准确度与精密度的方法,利用无效变量消除法（UVE）,对135个油菜籽样品近红外光谱信号进行筛选,并利用筛选后的光谱对油菜籽芥酸含量进行偏最小二乘法交叉验证。结果表明,UVE法筛选变量后建立的芥酸校正模型对未知样品预测结果的准确度和速度显著优于全波长参与建立的芥酸校正模型。散射校正加一阶导数对光谱预处理,UVE法筛选变量,偏最小二乘法交叉验证建立的校正模型效果最好,其预测值与标准值的相关系数R达到0.92,交叉验证预测均方差为2.2。因此,用UVE进行波长选择后建立的近红外模型,能准确快速地对油菜籽芥酸含量进行定量分析。     

The design of optimal sampling schemes for local estimation and mapping of regionalized variables—II: Program and examples

A FORTRAN IV program, OSSFIM, is presented for calculating estimation variances when interpolating by kriging from regular rectangular and triangular grids of data and previously-determined semi-variogram. The variances are computed for a range of grid spacings and block sizes, and the results graphed. The user chooses a block size, and can read from the appropriate graph the sample spacing corresponding to any prescribed maximum tolerable error. This is the optimal sampling scheme. Use of the program is illustrated with two examples showing different types of variation in soil. In one, the pH of topsoil is isotropic with a spherical semi-variogram and negligible nugget variance. An equilateral triangular grid is the best sampling scheme; it is approximately 10 per cent more efficient than a square grid. In the other example, variation is linear but anisotropic with a large nugget variance. In these circumstances, a triangular grid has no advantage over a rectangular one, which should be elongated in the ratio 1.88 to I in the direction of minimum variation.     

关于硫酸盐法蒸煮数学模型的若干问题

叙述了建立硫酸盐法蒸煮数学模型的若干问题，如数学模型的选择和建立，数学模型与多种参数的关系及工艺参数的测定等