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1.
本文在研究了网络安全的国内外有关情况后对网络安全技术进行了探讨 ,介绍了一种简单而实用的网络安全产品 ,添补了这方面的空白 ,而且本文介绍的产品已经应用到了许多部门 ,为网络安全做出了贡献  相似文献   

2.
在学习了反比例函数后,老师带大家总结了两个点及函数图像的对称性.对于两个一次函数对称的情况,我自己进行了探索,发现了  相似文献   

3.
标准体系的使用期的模型与分析   总被引:1,自引:1,他引:0  
本文提出了关于标准体系使用期的两个模型。首先定义了标准使用期,然后讨论了模型的合理性。通过模型讨论了标准使用期的性质,给出了数值示例。提出了需进一步研究的问题。  相似文献   

4.
孟令玮 《数学大王》2016,(Z1):74-75
笨笨熊买了套新房子,他请来了著名设计师聪明兔的家装团队来帮他装修。大约过了半个月,一天,聪明兔对笨笨熊说:"熊熊,客厅需要铺地板砖了,你赶紧去买……"聪明兔还没说完,笨笨熊说了一声"我现在就去买",就跑出门外了。笨笨熊兴冲冲地来到了机灵猴开的商店,只用一分钟就挑好了款式,谈好了价格。机灵猴笑眯眯地说:"我  相似文献   

5.
提出了一类Chen-like系统,研究了该系统奇点稳定性、混沌等动力学性态.讨论了Chen-like系中参数与阶数对系统混沌性态的影响,并给出了Chem-like系统出现混沌性态的阶次范围.与分数阶Chen系统相比,系统出现混沌性态的阶次范围增大了.根据分数阶系统稳定性理论及线性反馈控制,对系统进行了混沌控制,得出了混沌系统在平衡点处的稳定性条件.数值模拟验证了理论分析的正确性.  相似文献   

6.
分层教学的Bayes分析   总被引:3,自引:0,他引:3  
对学校分层教学进行了初步探索 ,提出了分层分班的 Bayes决策 ,介绍了分层分班方法 ,获得了一些结论 ,并完成了对这些结论的证明 ,从理论上论述了分层教学是实施“因材施教”教育原则和素质教育的有效途径 ,给出了应用实例 .  相似文献   

7.
伪造的遗书     
《数学大王》2009,(7):40-40
小试身手 杰森和助手里克匆匆赶到一家医院,给他们打电话的青年约翰迎接了他们。 “是这样的:我父亲昨天出了车祸住进了医院,我听到消息后立即从外地赶回来,但还是晚了一步,父亲在我到达前三小时去世了。  相似文献   

8.
本文研究了R_0代数上有关态算子的问题.利用MV-代数上内态的引入方法引入了态算子,定义了态R_0代数,它是R_0代数的一般化.给出了一些非平凡态R_0代数的例子并讨论了态R_0代数的一些基本性质.在此基础上给出了态滤子和态局部R_0代数的概念,并利用态滤子刻画了态局部R_0代数.推广了局部R_0代数的相关理论.  相似文献   

9.
一种积分数据的函数重构及其误差估计   总被引:1,自引:0,他引:1  
本文考虑了一种基于函数积分平均值的函数重构方法,在定义了一个插值算子之后建立了误差估计.从理论分析结果可以看出这种方法得到的解是适定的,因此我们不需要选择正则化参数,这样就简化了算法,而且最后一系列的数值结果很好的验证了这种方法的有效性.  相似文献   

10.
杨合俊 《大学数学》2014,(2):112-115
指出了一些微积分教辅书中一类极值问题的解答错误,分析了产生错误的原因,仔细研究了变量之间的关系,从而给出了正确的答案.  相似文献   

11.
在解析几何中有二次曲线与直线位置关系的讨论、二次曲面与直线位置关系的讨论,而二次曲面与平面相关位置关系的探讨较少.本文给出二次曲面a11x2+a22y2+a33z2+2a12xy+2a13xz+2a23yz+2a14x+2a24y+2a34z+a44=0(1)和平面Ax+By+Cz+D=0(2)的相对位置的判别式Δ=a11a12a13a14Aa21a22a23a24Ba31a32a33a34Ca41a42a43a44DA B C D0(aij=aji).(3)并证明了:若Δ>0,则二次曲面(1)与平面(2)相交;若Δ=0,则(1)和(2)相切;若Δ<0,则(1)和(2)相离.  相似文献   

12.
Scalarization of Henig Proper Efficient Points in a Normed Space   总被引:1,自引:0,他引:1  
In a general normed space equipped with the order induced by a closed convex cone with a base, using a family of continuous monotone Minkowski functionals and a family of continuous norms, we obtain scalar characterizations of Henig proper efficient points of a general set and a bounded set, respectively. Moreover, we give a scalar characterization of a superefficient point of a set in a normed space equipped with the order induced by a closed convex cone with a bounded base.  相似文献   

13.
This paper deals with a variant of a dynamical selection scheme introduced by Attouch and Cominetti for ill-posed convex minimization which combines approximation with the steepest descent method by mean of a suitable parameterization of the approximation parameter as a function of the time. This variant applies to a general inclusion with a maximal monotone operator by mean of a staircase parameterization. A discrete analogue is also considered. Applications to selecting a particular zero of a maximal monotone operator or a particular fixed point of a nonexpansive mapping via regularization techniques are presented. Finally, the alternative use of well-posedness by perturbations is discussed.  相似文献   

14.

The Rees algebra is the homogeneous coordinate ring of a blowing-up. The present paper gives a necessary and sufficient condition for a Noetherian local ring to have a Cohen-Macaulay Rees algebra: A Noetherian local ring has a Cohen-Macaulay Rees algebra if and only if it is unmixed and all the formal fibers of it are Cohen-Macaulay. As a consequence of it, we characterize a homomorphic image of a Cohen-Macaulay local ring. For non-local rings, this paper gives only a sufficient condition. By using it, however, we obtain the affirmative answer to Sharp's conjecture. That is, a Noetherian ring having a dualizing complex is a homomorphic image of a finite-dimensional Gorenstein ring.

  相似文献   


15.
A straight-line planar drawing of a plane graph is called a convex drawing if every facial cycle is drawn as a convex polygon. Convex drawings of graphs is a well-established aesthetic in graph drawing, however not all planar graphs admit a convex drawing. Tutte [W.T. Tutte, Convex representations of graphs, Proc. of London Math. Soc. 10 (3) (1960) 304–320] showed that every triconnected plane graph admits a convex drawing for any given boundary drawn as a convex polygon. Thomassen [C. Thomassen, Plane representations of graphs, in: Progress in Graph Theory, Academic Press, 1984, pp. 43–69] gave a necessary and sufficient condition for a biconnected plane graph with a prescribed convex boundary to have a convex drawing.In this paper, we initiate a new notion of star-shaped drawing of a plane graph as a straight-line planar drawing such that each inner facial cycle is drawn as a star-shaped polygon, and the outer facial cycle is drawn as a convex polygon. A star-shaped drawing is a natural extension of a convex drawing, and a new aesthetic criteria for drawing planar graphs in a convex way as much as possible. We give a sufficient condition for a given set A of corners of a plane graph to admit a star-shaped drawing whose concave corners are given by the corners in A, and present a linear time algorithm for constructing such a star-shaped drawing.  相似文献   

16.
17.
In this paper we introduce a new drawing style of a plane graph G called a box-rectangular drawing. It is defined to be a drawing of G on an integer grid such that every vertex is drawn as a rectangle, called a box, each edge is drawn as either a horizontal line segment or a vertical line segment, and the contour of each face is drawn as a rectangle. We establish a necessary and sufficient condition for the existence of a box-rectangular drawing of G. We also give a linear-time algorithm to find a box-rectangular drawing of G if it exists.  相似文献   

18.
给出了最佳参数α_1,α_2,α_3,β_1,β_2,β_3∈R,使得双向不等式α_1Q(a,b)+(1-α_1)G(a,b)0且a≠b成立.其中A(a,b)=(a+b)/2,H(a,b)=2ab/(a+b),G(a,b)=(ab)~(1/2),Q(a,b)=((a~2+b~2)/2)~(1/2),C(a,b)=(a~2+b~2)/(a+b),T(a,b)=2/π∫_0~(π/2)(a~2cos~2t+b~2sin~2)~(1/2)tdt分别是两个正数a和b的算术平均,调和平均,几何平均,二次平均,反调和平均和Toader平均.  相似文献   

19.
We study a decomposition of a general Markov process in a manifold invariant under a Lie group action into a radial part (transversal to orbits) and an angular part (along an orbit). We show that given a radial path, the conditioned angular part is a nonhomogeneous Lévy process in a homogeneous space, we obtain a representation of such processes and, as a consequence, we extend the well-known skew-product of Euclidean Brownian motion to a general setting.   相似文献   

20.
关于模N的原根的逆及其整除性   总被引:6,自引:0,他引:6  
王辉  胡志兴  高丽 《数学学报》1997,40(3):429-436
本文研究了模n的原根、逆及其整除性,并给出了一个关于min(a-a=1·k10、aaJ“+a-a)的较强的渐近公式。  相似文献   

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