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1.
运算的顺序由左向右、叉位相加,就是将多行加数的同位数的和数的个位数,加在本位上,和数的十位数,加在前位上,(二行、三行分段进位,按分节点,小数点分段,段内竖看二、三行加数,心算本位同位数的和数看后位,后位同位数的和数是进位数,提前进位;每段的首位数的同位数的和数是进位数,进行叉位相加,逐步达到一目两行、三行相加“一口清”。)心算起来比较容易.运算是边看数,边心算,边拨珠,眼不停看,心不停算,手不停拨,连续不断地运算,从而提高计算效率。 相似文献
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运算的顺序由左向右、叉位相加,就是将多行加数的同位数的和数的个位数,加在本位上,和数的十位数,加在前位上,(二行、三行分段进位,按分节点,小数点分段,段内竖看二、三行加数,心算本位同位数的和数看后位,后位同位数的和数是进位数,提前进位,每段的首位数的同位数的和数是进位数,进行叉位相加,逐步达到一目两行、三行相加“一口清”。)心算起来比较 相似文献
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《应用泛函分析学报》2016,(3)
针对现有灰色预测模型主要以一阶累加生成序列作为建模序列,再累减还原为原始序列预测值,本文通过Gamma函数将累加生成算子和累减生成算子拓展到正实数领域,给出分数阶累加生成算子和分数阶累减生成算子的解析表达式,一阶和整数阶均是其特例,证明了两算子之间的互逆性.为建立分数阶灰色预测模型和拓宽灰色预测模型的应用范围提供理论基础. 相似文献
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多项选择题测验真实分数的估计方法 总被引:1,自引:1,他引:0
本文在多项选择题观察分数Z等于真实分数Y与随机猜测分数X之和的假设模型下,给出了真实分数Y关于观察分数Z的回归函数,即真实分数Y的最优估计函数,并利用实际考试数据比较了真实分数的三种估计方法 相似文献
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谈谈数学考试中评分标准的制定 总被引:1,自引:1,他引:0
数学教育离不开解数学题,解数学题又不可避免地要对题进行评判.简单地说,谁做得既快又准谁做得就好,这只是质的方面的衡量,这种衡量比较适用于课堂实施,而对正式场合的书面表达而言,必须有一量化标准来体现解题的优劣程度,这种量化标准体现为考试中的分数.与其他科目一样,数学考试中的分数包含了三层运作:考前的评分标准、考后的评判分及根据不同需要对原始分数进行必要的数据加工处理. 相似文献
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在多项选择题测验分数等于真实分数和猜测分数之和的假设模型下,本文得到了一个多项选择题测验信度的理论公式,并由此给出了测验信度的估计方法。最后,通过两个例子,说明了本文提出的方法在测验信度分析中的应用,并将这种方法与教育测量中常用的库德——理查逊方法(Kuder-Richardson)进行了比较 相似文献
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X. Y. Zheng X. M. Yang K. L. Teo 《Journal of Optimization Theory and Applications》2007,133(2):275-288
We study efficient point sets in terms of extreme points, positive support points and strongly positive exposed points. In
the case when the ordering cone has a bounded base, we prove that the efficient point set of a weakly compact convex set is
contained in the closed convex hull of its strongly positive exposed points, thereby extending the Phelps theorem. We study
also the density of positive proper efficient point sets.
This research was supported by a Central Research Grant of Hong Kong Polytechnic University, Grant G-T 507. Research of the
first author was also supported by the National Natural Science Foundation of P.R. China, Grant 10361008, and the Natural
Science Foundation of Yunnan Province, China, Grant 2003A002M. Research of the second author was also supported by the Natural
Science Foundation of Chongqing. Research of the third author was supported by a research grant from Australian Research Counsil. 相似文献
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In this paper we review some results on the fractal geometry properties of the sets of thick points, thin points, fast points
and slow points derived from Lévy processes.
This work was supported by National Natural Science Foundation of China (Grant No. 10871200) 相似文献
13.
Comparison of Existence Results for Efficient Points 总被引:3,自引:0,他引:3
Existence results of maximal points with respect to general binary relations were stated by Hazen and Morin (Ref. 1) and by Gajek and Zagrodny (Ref. 2). In this paper, we point out that the natural framework for this problem is that of transitive and reflexive relations (preorders). The aim of this paper is to discuss existence results for maximal points with respect to general transitive relations in such a way that, when considering them for preorders defined by convex cones, we are able to recover most known existence results for efficient points; the quasi-totality of them, with their (short) proofs, is presented, too. 相似文献
14.
X. H. Gong 《Journal of Optimization Theory and Applications》1995,86(3):609-630
One of the important problems of vector optimization concerns the density of the set of positive proper minimal points in the set of minimal points. We use the concepts of dentable point and approximating cones to derive sufficient conditions guaranteeing that the set of minimal points is contained in the closure of the set of positive proper minimal points. The result can be applied to obtain a density result for the unit ball in 1
p
, 1<p<+, which does not follow from any other well-known density theorem.The author would like to thank Professor W. T. Fu for helpful comments. Moreover, the author is grateful to Professor H. P. Benson and the referees for valuable remarks and suggestions concerning a previous draft of this paper. 相似文献
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The question of the existence and the location of Darboux points (beyond which global optimality is lost) is crucial for minimal sufficient conditions for global optimality and for computation of optimal trajectories. Here, we investigate numerically the Darboux points and their relationship with conjugate points for a problem of minimum fuel, constant velocity, horizontal aircraft turns to capture a line. This simple second-order optimal control problem shows that ignoring the possible existence of Darboux points may play havoc with the computation of optimal trajectories.The authors are indebted to G. Moyer for his constructive comments. This research was supported, for the first author, by a National Research Council Associateship at NASA Ames Research Center.on leave from the Technion, Israel Institute of Technology, Haifa, Israel. 相似文献
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《Journal of the Egyptian Mathematical Society》2014,22(3):317-321
In this paper, we compute the 1-gap sequences of 1-Weierstrass points of non-hyperelliptic smooth projective curves of genus 10. Furthermore, the geometry of such points is classified as flexes, sextactic and tentactic points. Also, upper bounds for their numbers are estimated. 相似文献
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In this paper, locally uniformly rotund points and compactly locally uniformly rotund points are introduced. Moreover, criteria
for compactly locally uniformly rotund points in Orlicz spaces are given. 相似文献
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在非标准扩大模型下,给出了拓扑空间中集网收敛性的非标准刻画.首先,由非标准扩大模型的充要条件,证明了拓扑空间中集网的极限点和聚点的非标准刻画;然后,利用这些非标准特征,刻画了拓扑空间中集列、网和点列的极限点和聚点;最后,以自然的方式讨论了拓扑空间中集网上极限和下极限的一些重要性质. 相似文献
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Marlies Gerber 《Geometriae Dedicata》2003,98(1):123-160
We establish some criteria for the existence or nonexistence of focal points near closed geodesics on surfaces. These criteria are in terms of the curvature of the manifold along the closed geodesic and the average values of the partial derivatives of the curvature in the direction perpendicular to the geodesic. Our criteria lead to a new family of examples of surfaces with no focal points. We also show that if S is a compact surface with no focal points and an inequality relating the curvature of the surface to the curvature of the horocycles holds, then the horocycles (considered as curves in S) are uniformly C
2+Lipschitz. 相似文献
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Christopher Towse 《Transactions of the American Mathematical Society》1996,348(8):3355-3378
We are interested in cyclic covers of the projective line which are totally ramified at all of their branch points. We begin with curves given by an equation of the form , where is a polynomial of degree . Under a mild hypothesis, it is easy to see that all of the branch points must be Weierstrass points. Our main problem is to find the total Weierstrass weight of these points, . We obtain a lower bound for , which we show is exact if and are relatively prime. As a fraction of the total Weierstrass weight of all points on the curve, we get the following particularly nice asymptotic formula (as well as an interesting exact formula):
where is the genus of the curve. In the case that (cyclic trigonal curves), we are able to show in most cases that for sufficiently large primes , the branch points and the non-branch Weierstrass points remain distinct modulo .