共查询到20条相似文献,搜索用时 109 毫秒
1.
图G称为上连通的,若对每个最小割集C,G-C有孤立点,G称为超连通的,若对每个最小割集C,G-C恰有两个连通分支,且其中之一为弧立点,本文刻划了上连通和超连通三次点传递图。 相似文献
2.
图G称为上连通的,若对每个最小割集C,G-C有孤立点.G称为超连通的,若对每个最小割集G,G-C恰有两个连通分支,且其中之一为孤立点.本文刻划了上连通和超连通三次点传递图. 相似文献
4.
本文证明了若G是连通、局部连通的无爪图,则G是泛连通图的充要条件为G是3-连通图.这意味着H.J.Broersma和H.J.Veldman猜想成立. 相似文献
5.
6.
本文证明了任意边界可约流形的Heegaard分解都是n个不可约的、边界不可约的三维流形的Heegaard分解通过连通和、边界连通和及边界自连通和运算而得到. 相似文献
7.
8.
张静 《高校应用数学学报(A辑)》2017,32(1)
给出连通的rectifiable空间是局部序列连通(或局部连通)的刻画,推广了拓扑群中的相应结果;利用rectifiable空间G中e的局部邻域基给出G是局部连通(或局部序列连通)的刻画;证明了若A是rectifiable空间G中的序列开子集,那么H=A是G的序列开rectifiable子空间. 相似文献
9.
设G=(V,E)为简单图,δ为图G的最小度,1987年Faudree等人给出NC=min{|N(x)∪N(y)‖x,y∈V(G),xy∈N(G)},有关文献曾研究3连通的H连通图,本文进一步得到:若G是n阶2连通图,且NC≥n-δ,则G除几个图外均是H连通图,从而,完成了邻并条件的H连通图问题。 相似文献
10.
11.
12.
13.
Symmetry of graphs has been extensively studied over the past fifty years by using automorphisms of graphs and group theory which have played and still play an important role for graph theory, and promising and interesting results have been obtained, see for examples, [L.W. Beineke, R.J. Wilson, Topics in Algebraic Graph Theory, Cambridge University Press, London, 2004; N. Biggs, Algebraic Graph Theory, Cambridge University Press, London, 1993; C. Godsil, C. Royle, Algebraic graph theory, Springer-Verlag, London, 2001; G. Hahn, G. Sabidussi, Graph Symmetry: Algebraic Methods and Application, in: NATO ASI Series C, vol. 497, Kluwer Academic Publishers, Dordrecht, 1997]. We introduced generalized symmetry of graphs and investigated it by using endomorphisms of graphs and semigroup theory. In this paper, we will survey some results we have achieved in recent years. The paper consists of the following sections.
- 1. Introduction
- 2. End-regular graphs
- 3. End-transitive graphs
- 4. Unretractive graphs
- 5. Graphs and their endomorphism monoids.
Keywords: Graph; Endomorphism; Monoid; Generalized symmetry; End-regular; End-transitive; Unretractive 相似文献
14.
How much information does a small number of moments carry about the unknown distribution function? Is it possible to explicitly obtain from these moments some useful information, e.g., about the support, the modality, the general shape, or the tails of a distribution, without going into a detailed numerical solution of the moment problem? In this, previous and subsequent papers, clear and easy to implement answers will be given to some questions of this type. First, the question of how to distinguish between the main-mass interval and the tail regions, in the case we know only a number of moments of the target distribution function, will be addressed. The answer to this question is based on a version of the Chebyshev–Stieltjes–Markov inequality, which provides us with upper and lower, moment-based, bounds for the target distribution. Then, exploiting existing asymptotic results in the main-mass region, an explicit, moment-based approximation of the target probability density function is provided. Although the latter cannot be considered, in general, as a satisfactory solution, it can always serve as an initial approximation in any iterative scheme for the numerical solution of the moment problem. Numerical results illustrating all the theoretical statements are also presented. 相似文献
15.
This paper deals with the notion of residual income, which may be defined as the surplus profit that residues after a capital charge (opportunity cost) has been covered. While the origins of the notion trace back to the 19th century, in-depth theoretical investigations and widespread real-life applications are relatively recent and concern an interdisciplinary field connecting management accounting, corporate finance and financial mathematics (Peasnell, 1981, 1982; Peccati, 1987, 1989, 1991; Stewart, 1991; Ohlson, 1995; Arnold and Davies, 2000; Young and O’Byrne, 2001; Martin, Petty and Rich, 2003). This paper presents both a historical outline of its birth and development and an overview of the main recent contributions regarding capital budgeting decisions, production and sales decisions, implementation of optimal portfolios, forecasts of asset prices and calculation of intrinsic values. A most recent theory, the systemic-value-added approach (also named lost-capital paradigm), provides a different definition of residual income, consistent with arbitrage theory. Enfolded in Keynes’s (1936) notion of user cost and forerun by Pressacco and Stucchi (1997), the theory has been formally introduced in Magni (2000a,b,c; 2001a,b; 2003), where its properties are thoroughly investigated as well as its relations with the standard theory; two different lost-capital metrics have been considered, for value-based management purposes, by Drukarczyk and Schueler (2000) and Young and O’Byrne (2001). This work illustrates the main properties of the two theories and their relations, and provides a minimal guide to construction of performance metrics in the two approaches. 相似文献
16.
17.
In this paper, we consider the effect of diffusion on the permanence and extinction of a non-autonomous nonlinear growth rate single-species dispersal model with time delays. Firstly, the sufficient conditions of the permanence and extinction of the species are established, which shows if the growth rate and dispersal coefficients is suitable, the species is permanent, on the contrary, it is extinction. Secondly, an interesting result is established, that is, if only the species in some patches even in one patch is permanent, then it is also permanent in other patches. Finally, some examples together with their numerical simulations show the feasibility of our main results. 相似文献
18.
互连网络的向量图模型 总被引:1,自引:0,他引:1
n-超立方体,环网,k元n超立方体,Star网络,煎饼(pancake)网络,冒泡排序(bubble sort)网络,对换树的Cayley图,De Bruijn图,Kautz图,Consecutive-d有向图,循环图以及有向环图等已被广泛的应用做处理机或通信互连网络.这些网络的性能通常通过它们的度,直径,连通度,hamiltonian性,容错度以及路由选择算法等来度量.在本文中,首先,我们提出了有向向量图和向量图的概念;其次,我们开发了有向向量图模型和向量图模型来更好地设计,分析,改良互连网络;我们进一步证明了上述各类著名互连网络都可表示为有向向量图模型或向量图模型;更重要的是该模型能够使我们设计出了新的互连网络---双星网络和三角形网络. 相似文献
19.
J. Sakalauskaite 《Lithuanian Mathematical Journal》2005,45(2):217-224
We consider a propositional dynamic logic for agents with interactions such as known commitment, no learning, and perfect recall. For this logic, we present a sequent calculus with a restricted cut rule and prove the soundness and completeness for the calculus.__________Published in Lietuvos Matematikos Rinkinys, Vol. 45, No. 2, pp. 261–269, April–June, 2005. 相似文献
20.
Leo G. Rebholz 《Journal of Mathematical Analysis and Applications》2007,326(1):33-45
The conservation of mass, momentum, energy, helicity, and enstrophy in fluid flow are important because these quantities organize a flow, and characterize change in the flow's structure over time. In turbulent flow, conservation laws remain important in the inertial range of wave numbers, where viscous effects are negligible. It is in the inertial range where energy, helicity (3d), and enstrophy (2d) must be accurately cascaded for a turbulence model to be qualitatively correct. A first and necessary step for an accurate cascade is conservation; however, many turbulent flow simulations are based on turbulence models whose conservation properties are little explored and might be very different from those of the Navier-Stokes equations.We explore conservation laws and approximate conservation laws satisfied by LES turbulence models. For the Leray, Leray deconvolution, Bardina, and Nth order deconvolution models, we give exact or approximate laws for a model mass, momentum, energy, enstrophy and helicity. The possibility of cascades for model quantities is also discussed. 相似文献