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171.
态射的和与积的Moore-Penrose逆   总被引:1,自引:0,他引:1  
态射的Moore-Penrose逆是矩阵的Moore-Penrose逆在有对合*的范畴中的推广。本文给出加法范畴及Abel范畴中态射的和与积的Moore-Penrose逆存在的充分条件和一些性质。  相似文献   
172.
ON ORTHOGONAL (0,f)-FACTORIZATIONS   总被引:1,自引:0,他引:1  
1991MRSubjectClassification05C701IntroductionAllgraphsconsi(lere(1arefilliteulldirectedsimplegraphs.LetgandfI)einteger-v;tllle(1fllnctionsdefinedonV(G)suchthat05g(x)5f(x)foreverya:EV(G).A(g,f)--tActorofGisaspanningsubgraphFofGsuchthatg(x)5da(x)5f(x)foreveryxEV(G).IfGitselfisa(g,f)-factor,thenGiscalls(1a(g,f)--graph.A(g,f)--factorizationF={FI,F2,'.F,,,}ofGisapartitionofGilltoedge-disjoint(g,f)--factorsFI5F2,'5Fm.LetHbeasubgrapllofGwith?nedges,thenFiscalledorthogonaltoHifeach…  相似文献   
173.
1.IntroductionRecelltlymuchworkhasbeencarriedoutinthestudyoftheseparationofvariablesofacompletelyintegrableHalniltoniansystemll--6].Forclassicalilltegrablesystemssubjecttoinversescatteringtransformationthestandardconstructionoftheaction-anglevariablesusingthepolesoftheBaker-Anheizerfullctionisequivalenttotheseparationofvariablesl31.Theabategapsolutionsofthesolitonequationsareconstructedduetotheseparationofvariablesofthestationarysolitonequationsll].Forsomekindoffinite-dimensionalintegrableHt…  相似文献   
174.
Rabin's cryptosystem was proved to be as hard as factorization. However, Rabin's digital signature schemes is probabilistic. This paper shows two efficient Rabin type digital signature schemes, a basic scheme and an improved scheme. Both schemes run much faster than Rabin's scheme. They are deterministic and the size of a signature is much smaller than that of a signature in Rabin's scheme. Furthermore, it is proved that, by applying the technique of Bellare and Rogaway, the proposed scheme is secure against chosen plaintext attack. More precisely, breaking the proposed digital signature scheme by chosen plaintext attack is as hard as factoring N.  相似文献   
175.
陈协彬 《数学研究》1999,32(2):146-150
设 n1 ≥ n 2 ≥ … ≥ nk ≥ 2 是整数. 若图 G 能边分解成 G1  G2  …  Gk , 这里 χ( Gi) = n i, i=1,2,…,k ,则称 G 有(n1 , n2 , …, nk )色因子 分解. 本文改进 了 Hakim i和 Schm eich el 关于图的色因 子分解的结果,作为推 论,推广了 M atula 和 Harary 等人的结果  相似文献   
176.
In this paper, we study the Generalized Minimal Residual (GMRES) method for solving singular linear systems, particularly when the necessary and sufficient condition to obtain a Krylov solution is not satisfied. Thanks to some new results which may be applied in exact arithmetic or in finite precision, we analyze the convergence of GMRES and restarted GMRES. These formulas can also be used in the case when the systems are nonsingular. In particular, it allows us to understand what is often referred to as stagnation of the residual norm of GMRES. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
177.
We prove a factorization result for relatively compact subsets of compact operators using the Bartle and Graves Selection Theorem, a characterization of relatively compact subsets of tensor products due to Grothendieck, and results of Figiel and Johnson on factorization of compact operators. A further proof, essentially based on the Banach-Dieudonné Theorem, is included. Our methods enable us to give an easier proof of a result of W.H. Graves and W.M. Ruess.

  相似文献   

178.
In this paper, under assumption that tempeature is linearly distributed along the thickness of the shell, we deal with problems as indicated in the title and obtain general solutions of them which are expressed in analytic form.In the first part, we investigate free vibration of circular shallow spherical shells with circular holes at the center under usual arbitrary boundary conditions. As an example, we calculate fundamental natural frequency of a circular shallow spherical shell whose edge is fixed (m=0). Results we get are expressed in analytic form and check well with E. Reissner’s [1]. Method for calculating frequency equation is recently suggested by Chien Wei-zang and is to be introduced in appendix 3.In the second part, we investigate forced vibration of shells as indicated in the title under arbitrary harmonic temperature field and arbitrary harmonic dynamic normal load.In the third part, we investigate forced vibration of the above mentioned shells with initial conditions under arbitrary unsteady temperature field and arbitrary normal load.In appendix 1 and 2, we discuss how to express displacement boundary conditions with stress function and boundary conditions in the case m=1.  相似文献   
179.
与路2—正交的(g,f)—因子分解   总被引:5,自引:2,他引:3  
设g和f分别是定义在图G的机点集合V(G)上的整数值函数且对每个x∈V(G)有4≤g(x)≤f(x)。证明了若G是一个(mg+m-1,mf-m+1)-图,则对G中任意给定的长为2m的路P,G有一个(g,f_-因子分解2-正交于P。  相似文献   
180.
改进与数论函数σ(n)(整数n的所有正因数的和)及Euler函数φ(n)有关的几个不等式,并对不等式σ(n)^φ(n)〈n^n〈φ(n)^σ(n)(n∈Z且n≥7)给出了一个较为简便的证明。  相似文献   
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