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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.
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   

3.
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   

4.
高阶数值微分的积分方法   总被引:1,自引:1,他引:0  
本文研究了高阶数值微分问题,利用Groetsch的思想,获得了可以稳定逼近近似已知函数的任意阶导数的积分方法,并在一定条件下,给出了收敛率.给出了二阶、三阶和四阶数值微分问题的数值实验,实验结果表明了方法的有效性.  相似文献   

5.
模糊幂格     
彭家寅 《数学杂志》2008,28(1):45-49
本文研究了格向其模糊幂集上提升的问题.利用模糊集理论,引入了模糊幂格的概念,获得了模糊幂格及其模糊理想的若干基本性质,推广了格的结果.  相似文献   

6.
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   

7.
秩为1矩阵的性质及应用   总被引:1,自引:0,他引:1  
给出了秩1矩阵的结构,讨论了这类矩阵在矩阵运算、对角化、标准型等方面的性质,推广和改进了文[1]的一些相关结果,并指出了它的若干应用,重点讨论了一类矩阵,得到了有关结论和方法.  相似文献   

8.
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   

9.
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   

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.
The hub covering flow problem (HCFP) seeks to find the minimal cost hub-and-spoke network by optimally locating hub nodes and assigning non-hub nodes to the hub nodes subject to a coverage constraint. The cost of establishing such a hub network is based on a fixed cost of opening hubs and the cost of transporting demand flow through the network. We also present an extension called the multi-aircraft HCFP. The results from computational experiments are presented and discussed.  相似文献   

12.
弹性力学求解体系的研究   总被引:3,自引:1,他引:2  
证明了弹性力学求解体系的微分形式与积分形式的等价关系,建立了统一求解体系构架.新体系包括微分形式、积分形式及混合形式.利用微分形式与积分形式的等价关系,导出了各种变分原理.提出了广义虚功方程和广义虚函数的概念.  相似文献   

13.
Given a d × d quasiconvex quadratic form, d ≥ 3, we prove that if the determinant of its acoustic tensor is an irreducible extremal polynomial that is not identically zero, then the form itself is an extremal quasiconvex quadratic form; i.e., it loses its quasiconvexity whenever a convex quadratic form is subtracted from it. In the special case d=3, we slightly weaken the condition; namely we prove that if the determinant of the acoustic tensor of the quadratic form is an extremal polynomial that is not a perfect square, then the form itself is an extremal quadratic form. In the case d=3 we also prove that if the determinant of the acoustic tensor of the form is identically zero, then the form is either extremal or polyconvex. Also, if the determinant of the acoustic tensor of the form is a perfect square, then the form is either extremal or polycovex, or is a sum of a rank‐1 form and an extremal whose acoustic tensor determinant is identically zero. Here we use the notion of extremality introduced by Milton in 1990. © 2017 Wiley Periodicals, Inc.  相似文献   

14.
黄礼平 《数学学报》2008,51(2):371-380
设D为除环,A∈Dn×n,则可用初等变换将λI-A化简为对角阵A= diag(1,…,1,φ1,…,φr),其中(?)i为D上首1多项式并且φ1|…|φr.如果这个对角阵A在形状上是唯一的,则称A是有强法式的矩阵.本文应用中心原子因子与初等因子给出了体上有强法式的矩阵的本质刻画,给出了体上矩阵有强法式的一些充要条件.  相似文献   

15.
提出了一个确定张拉结构初始几何形状的形状函数.基于该形状函数,通过对结构边界控制点的插值确定张拉结构的初始形状.该结构形状可随结构的双向张力比和边界控制点的坐标而进行自动调整.从而给出了几何上可行,力学上合理的高精度张拉曲面.通过有限元方法检查,大量例子表明该方法确定的初始形状对于实际常用边界及双向等拉或不等拉张结构均十分理想,误差很小.  相似文献   

16.
The present paper gives a direct proof of the following result: for any linear operator over arbitrary field there exists a basis in which it has a polyquasicyclic matrix, i.e. a generalized Jordan form of second kind. The polyquasicyclic form of a linear operator is uniquely determined up to the order of direct summands on the diagonal, and it is shown that the generalized Jordan form of second kind is a link that connects the classical Jordan form and the rational canonical form.  相似文献   

17.
Summary We shall introduce a 1-form which is called V-Killing form in a locally conformal K?hler manifold with the parallel Lee form and prove that this form has similar properties of C-Killing form in a Sasakian manifold. We obtain that a V-harmonic form is invariant by a V-Killing form. Entrata in Redazione il 4 agosto 1978.  相似文献   

18.
The aim of this paper is to show the role of first integrals in further reducing the normal form unfolding of Hamiltonian systems. Based on a work by Cicogna and Gaeta, the joint normal form approach for Hamiltonian vector fields is considered. This normal form procedure, couched in a Lie-Poincaré scheme, allows us to see that we can reduce simultaneously the Hamiltonian together with its Poisson commuting integrals to a simplified normal form - a joint normal form - which is given a simple characterization. In this algorithmic procedure, approximate first integrals can be constructed (and used to simplify the normal form) at the same time that we bring the Hamiltonian to normal form. Further, following Walcher, we show that we can derive the joint normal form via a structure preserving transformation (in a sense to be specified). The approach is discussed from an implementational standpoint and illustrated by a Liouville-integrable Hénon-Heiles system. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

19.
We offer an algorithm to determine the form of the normal form for a vector field with a nilpotent linear part, when the form of the normal form is known for each Jordan block of the linear part taken separately. The algorithm is based on the notion of transvectant, from classical invariant theory.  相似文献   

20.
In this paper, we introduce two new forms of the half-discrete Hilbert inequality. The first form is a sharper form of the half-discrete Hilbert inequality and is related to Hardy inequality. In the second one, we give a differential form of this inequality.  相似文献   

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