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1.
The reflector antenna design problem requires to solve a second boundary value problem for a complicated Monge-Ampére equation, for which the traditional discretization methods fail. In this paper we reduce the problem to that of finding a minimizer or a maximizer of a linear functional subject to a linear constraint. Therefore it becomes an linear optimization problem and algorithms in linear programming apply.Received: 7 July 2003, Accepted: 26 August 2003, Published online: 15 October 2003Mathematics Subject Classification (2000): 78A05, 28A50This work was supported by the Australian Research Council.  相似文献   

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医学研究中标准曲线修正的初探   总被引:4,自引:0,他引:4  
目的:在医学研究和临床检验中经常使用定量检测法,在该方法中标准曲线被广泛应用,且其准确性直接影响检测结果.从统计学角度对其进行修正,使结果更为可靠.方法:应用直线回归法对直线型标准曲线进行处理,求出直线回归方程;对曲线型标准曲线,先将指数方程取对数后变成直线方程,然后求直线回归方程后再回代,求出曲线回归方程.结果:以蛋白量与其对应的OD值间关系求得直线回归方程y=0 .0 0 6x;以TNFα浓度与对应的OD值间关系求得指数回归方程y=0 .0 1 5 x0 .732 ,对两者进行F检验,回归效果均极显著.结论:应用回归法可获得定量检测法中常用的直线型及曲线型标准曲线的方程,据此可直接计算出待测样本所需数据,使其更为简便、准确、可靠.  相似文献   

4.
In the first part of this paper we proof the following theorem: Let E and F be topological linear spaces, α an infinite cardinal number, and H a set of linear mappings from E into F such that every subset G of H with cardinality |G|≤α is equicontinuous. Then H is equicontinuous on every linear subspace of E which is the closed linear hull of a family (BL;L∈I), |I|≤α, of precompact subsets of E. In the second part we introduce the class of all topological linear spaces E with the following property: A set H of linear mappings from E into a topological linear space is equicontinuous, if every countable subset of H is equicontinuous. We show that this class is closed with respect to forming topological products and linear final topologies.  相似文献   

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The determinant is a very important characteristic of a linear map between vector spaces. Two generalizations of linear maps are intensively used in modern theory: linear complexes (nilpotent chains of linear maps) and nonlinear maps. The determinant of a complex and the resultant are then the corresponding generalizations of the determinant of a linear map. It turns out that these two quantities are related: the resultant of a nonlinear map is the determinant of the corresponding Koszul complex. We give an elementary introduction into these notions and relations, which will definitely play a role in the future development of theoretical physics.  相似文献   

6.
Assume A is a normed linear space, B is a Banach space, and f: AB is a mapping “approximately linear.” We solve the following Ulam problem: “Give conditions in order for a linear mapping near an approximately linear mapping to exist.”  相似文献   

7.
We introduce some invariants of singularities which represent the anti-freeness of the adjoint linear systems. The invariants indicate that if either the singularities or the boundaries are worse then the adjoint linear systems are much global generative. Using these invariants, we prove effective global generation of adjoint linear systems on normal log surfaces. Received: 14 May 1999/ Revised version: 2 August 1999  相似文献   

8.
有限总体中的最优预测   总被引:10,自引:1,他引:9  
研究了有限总体中的最优预测问题,在一般Gauss-Markov模型下得到了线性可预测变量的最优线性无偏预测,特别地,考虑了一类特殊的预测函数:b-线性预测函数。  相似文献   

9.
The general mixed linear model can be written as . In this paper, we mainly deal with two problems. Firstly, the problem of predicting a general linear combination of fixed effects and realized values of random effects in a general mixed linear model is considered and an explicit representation of the best linear unbiased predictor (BLUP) is derived. In addition, we apply the resulting conclusion to several special models and offer an alternative to characterization of BLUP. Secondly, we recall the notion of linear sufficiency and consider it as regards the BLUP problem and characterize it in several different ways. Further, we study the concepts of linear sufficiency, linear minimal sufficiency and linear completeness, and give relations among them. Finally, four concluding remarks are given.  相似文献   

10.
There are many papers dealing with the approximate solution of linear problems where only partial information is available. Two types of information have been considered: linear and discontinuous nonlinear. In particular, we know that discontinuous nonlinear information is far more powerful than linear information. In this paper we study continuous nonlinear information for linear problems, and we prove that:
• -it is no more powerful than linear information in the worst case setting,
• -it is much more powerful than linear information in the average case setting.
  相似文献   

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