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91.
92.
Ahmed Ainouche 《Graphs and Combinatorics》2009,25(2):129-137
Let G = (V, E) be a any simple, undirected graph on n ≥ 3 vertices with the degree sequence . We consider the class of graphs satisfying the condition where , is a positive integer. It is known that is hamiltonian if θ ≤ δ. In this paper,
相似文献
(i) | we give a necessary and sufficient condition, easy to check, ensuring that is nonhamiltonian and we characterize all the exceptional sub-classes. |
(ii) | we prove that is either bipartite or contains cycles of all lengths from 3 to c(G), the length of a longest cycle in G. |
93.
Carles Bivià-Ausina 《Mathematische Zeitschrift》2009,262(2):389-409
Let be a finite analytic map. We give an expression for the local Łojasiewicz exponent and for the multiplicity of g when the component functions of g satisfy certain condition with respect to a set of n monomial ideals I
1,..., I
n
. We give an effective method to compute Łojasiewicz exponents based on the computation of mixed multiplicities. As a consequence
of our study, we give a numerical characterization of a class of functions that includes semi-weighted homogenous functions
and Newton non-degenerate functions.
Work supported by DGICYT Grant MTM2006-06027. 相似文献
94.
G. R. Bates 《Journal of Optimization Theory and Applications》1978,24(4):639-649
Lower closure theorems are proved for optimal control problems governed by ordinary differential equations for which the interval of definition may be unbounded. One theorem assumes that Cesari's property (Q) holds. Two theorems are proved which do not require property (Q), but assume either a generalized Lipschitz condition or a bound on the controls in an appropriateL
p-space. An example shows that these hypotheses can hold without property (Q) holding. 相似文献
95.
John E. van den Berg 《Acta Mathematica Hungarica》2005,107(3):177-186
Summary A radical R , in the sense of Kurosh--Amitsur, is said to be compact if, given any collection of radicals X such that R ≤;VX , we have R ≤;VX ' for some finite subcollection X ' of X. A ring A is said to be radical compact if the lower radical on the singleton {A } is compact. This paper explores the relationship between radical compact rings and rings satisfying certain finiteness conditions. Closure properties of the class of all radical compact rings are also investigated. 相似文献
96.
J.-F. Ripoll A.A. Wray 《Journal of Quantitative Spectroscopy & Radiative Transfer》2005,93(4):473-519
We present in this paper a new 3D half-moment model for radiative transfer in a gray medium, called the model, which uses maximum entropy closure. This model is a generalization to 3D of the 1D version recently proposed in (J. Comp. Phys. 180 (2002) 584). The direction space Ω is divided into two pieces, Ω+ and Ω-, in a dynamical way by the plane perpendicular to the total radiative flux, and the half moments are defined from these subspaces. The model closure and the integrations of the radiative transfer equation performed on the moving Ω± spaces are detailed. 1D planar results, which have motivated the extension of the model of (J. Comp. Phys. 180 (2002) 584) to multi-dimensions, are shown. These results are very good. The model is thereafter derived for 3D spherically symmetric geometry, where the correctness of the non-trivial border terms can be checked. Two 3D spherically symmetric problems are numerically solved in order to show the accuracy of the closure and the role of the border terms. Once again, compared to the solution obtained with a ray tracing solver, results are very good. From the 3D half-moment model, a new moment model, called , is derived for the particular case of a 3D hot and opaque source radiating into a cold medium, for applications such as simulations of stellar atmospheres and fires. Two-dimensional numerical results are presented and compared to those obtained solving the RTE and with other moment models. They demonstrate the very good accuracy of the model, its good convergence properties, and better prediction compared to all other existing moment models in its domain of applicability. 相似文献
97.
In this paper we study the families of ETOL and EOL array languages. Standard forms for ETOL and EOL array systems are defined
and closure properties of the families are studied. Relations of these families with other developmental array languages and
other array languages are studied. 相似文献
98.
99.
Á Császár 《Acta Mathematica Hungarica》2002,95(1-2):83-99
We study properties of the operation
, defined for structures corresponding to different subcategories of MER, as merotopies, filter merotopies, contiguities,
-contiguities and closures. In particular, we examine commutativity of
and the operation according to which a structure induces a structure of another type (as e.g.\ a merotopy induces a closure) and the inverse operations of the former. 相似文献
100.
Gábor Hetyei 《Graphs and Combinatorics》2002,18(3):533-564