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921.
A norm on a group G is a function N mapping G into the set ofnon-negative real numbers such that for each x and y in G, N(xy–1) N(x)+N(y) and N(e) = 0, where e is the identity element ofG. It is shown here that if F(X) is the free topological groupon any completely regular Hausdorff space X and H is a subgroupof F(X) generated by a finite subset of X, then any norm onH can be extended to a continuous norm on F(X). 相似文献
922.
923.
In the current contribution, we present a multi-scale constitutive model capturing macroscopic inelastic effects (like stress softening and permanent set) in soft tissues under cyclic loading. Soft biological tissues can be described as a biological composite material. The extracellular matrix is hereby reinforced by collagen fibers which themself are an assembly of collagen fibrils embedded in a proteoglycan (PG) rich matrix. Micro-damage induced by cyclic loading is treated by an interaction scenario between the fibrils and the PGs. At the low strain regime PGs promote sliding between fibrils [1] which leads to the yielding of statistical distributed overlapping segments. The breakage of the PG-bridges is defined by a decreasing PG-density. Due to the accumulated damage of the PG connections at high tissue strains, the strains at the fibril level increases. This finally drives the over-stretching of the fibrils, which is associated with a permanent rupture of the hydrogen bonds inside of the tropocollagen molecules [2]. The so obtained model is in line with recent experimental findings [1, 2] and was additionally validated against experimental data available in literature. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
924.
925.
We study the optimal premium policy of mutual insurance when the charged premium cannot be higher than a preset rate. We provide a complete solution to the problem and use numerical simulations to illustrate how the optimal premium policy responds to changes of outside factors. The results are useful for mutual insurance firms to design premium policies and can be used to test the behavior of these firms in empirical studies. 相似文献
926.
The chemical master equation is an important model for studying chemical kinetics, especially in the context of systems biology where noise is known to play an important role and so a discrete and stochastic framework is required. However due to the high dimensional nature of the equations it has often been felt to be too difficult to tackle numerically, although recently much progress has been made. Here some novel numerical methods are presented and applied to stochastic models of receptor oligomerisation, which have previously been studied only by simulation. This gives a novel perspective on these models and suggests some insights into the phenomena of the role they play in buffering cell signals. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
927.
Kevin P. Knudson 《代数通讯》2013,41(12):3904-3908
We compute the completion of the special linear group over the coordinate ring A of a curve over a number field k relative to its representation in SL n (A/𝔪), for 𝔪 a maximal ideal. 相似文献
928.
Kevin De Laet 《代数通讯》2013,41(10):4258-4282
In this article, we study graded Clifford algebras with a gradation preserving action of automorphisms given by H p , the Heisenberg group of order p 3 with p prime. After reviewing results in dimensions 3 and 4, we will determine the graded Clifford algebras that are AS-regular algebras of global dimension 5 and generalize certain results to arbitrary dimension p. 相似文献
929.
930.
The concept of scale-free networks has been widely applied across natural and physical sciences. Many claims are made about the properties of these networks, even though the concept of scale-free is often vaguely defined. We present tools and procedures to analyse the statistical properties of networks defined by arbitrary degree distributions and other constraints. Doing so reveals the highly likely properties, and some unrecognised richness, of scale-free networks, and casts doubt on some previously claimed properties being due to a scale-free characteristic.https://doi.org/10.1209/0295-5075/103/58004 相似文献