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261.
R. Willox  B. Grammaticos 《Physica A》2007,385(2):473-486
We examine the transition between discrete and ultradiscrete (cellular-automaton-like) systems, the dynamics of which exhibit limit cycles. Motivated by results obtained previously for three-dimensional systems, we consider here a more manageable two-dimensional model. We show that one can follow the changes in dynamics of the system when a parameter that tunes the discrete-ultradiscrete transition is varied. In particular we explain the phenomenon of the splitting of a discrete limit cycle to a profusion of periodic orbits at the ultradiscrete limit.  相似文献   
262.
In this paper, we consider a generalized iterative process with errors to approximate the common fixed points of two asymptotically quasi-nonexpansive mappings. A convergence theorem has been obtained which generalizes a known result. This theorem has then been used to prove another convergence theorem which, in turn, generalizes a number of results.  相似文献   
263.
We prove a Delorme-Guichardet type theorem for discrete quantum groups expressing property (T) of the quantum group in question in terms of its first cohomology groups. As an application, we show that the first L2-Betti number of a discrete property (T) quantum group vanishes.  相似文献   
264.
Let G=(V,E) be a graph and let r≥1 be an integer. For a set DV, define Nr[x]={yV:d(x,y)≤r} and Dr(x)=Nr[x]∩D, where d(x,y) denotes the number of edges in any shortest path between x and y. D is known as an r-identifying code (r-locating-dominating set, respectively), if for all vertices xV (xV?D, respectively), Dr(x) are all nonempty and different. Roberts and Roberts [D.L. Roberts, F.S. Roberts, Locating sensors in paths and cycles: the case of 2-identifying codes, European Journal of Combinatorics 29 (2008) 72-82] provided complete results for the paths and cycles when r=2. In this paper, we provide results for a remaining open case in cycles and complete results in paths for r-identifying codes; we also give complete results for 2-locating-dominating sets in cycles, which completes the results of Bertrand et al. [N. Bertrand, I. Charon, O. Hudry, A. Lobstein, Identifying and locating-dominating codes on chains and cycles, European Journal of Combinatorics 25 (2004) 969-987].  相似文献   
265.
266.
Recent developments in dynamic kinetic resolution   总被引:1,自引:0,他引:1  
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267.
A nontrivial solution is obtained for a class of superquadratic elliptic problems by variational methods.  相似文献   
268.
The authors apply a classical series identity involving the psi (or digamma) function with a view to deriving series representations for a number of known mathematical constants. Several closely-related consequences and results are also considered.  相似文献   
269.
Let M be a smooth, compact, orientable, weakly pseudoconvex manifold of dimension 3, embedded in (N2), of codimension one or more, and endowed with the induced CR structure. Assuming that the tangential Cauchy-Riemann operator has closed range in L2(M) in order to rule out the Rossi example, we push regularity up to show has closed range in Hs(M) for all s>0. We then use the Szegö projection to show there is a smooth solution for the problem given smooth data. The results are obtained via microlocalization by piecing together estimates for functions and (0,1) forms that hold on different microlocal regions.  相似文献   
270.
We give various necessary and sufficient conditions for an AF-algebra to be isomorphic to a graph C-algebra, an Exel-Laca algebra, and an ultragraph C-algebra. We also explore consequences of these results. In particular, we show that all stable AF-algebras are both graph C-algebras and Exel-Laca algebras, and that all simple AF-algebras are either graph C-algebras or Exel-Laca algebras. In addition, we obtain a characterization of AF-algebras that are isomorphic to the C-algebra of a row-finite graph with no sinks.  相似文献   
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