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141.
142.
该文得到了凸度量空间上混合映射的共同点的一些结果.推广了Ciric在文献[3]中的结论. 相似文献
143.
文章利用正规对偶映射的定义,给出了任意Banach空间Lipschitz强伪压缩映射不动点的Ishikawa迭代收敛定理.该定理不仅推广了已知结果,而且还简化了目前相应结果的证明. 相似文献
144.
We establish the additive theorem of L^2-decay rate for multi- dimensional Markov process with independent marginal processes. Using this and the decomposition method, we obtain explicit upper and lower bounds for decay rate of non-ergodic Jackson network. In some cases, we get the exact decay rate. 相似文献
145.
In many applications,covariates can be naturally grouped.For example,for gene expression data analysis,genes belonging to the same pathway might be viewed as a group.This paper studies variable selection problem for censored survival data in the additive hazards model when covariates are grouped.A hierarchical regularization method is proposed to simultaneously estimate parameters and select important variables at both the group level and the within-group level.For the situations in which the number of parameters tends to∞as the sample size increases,we establish an oracle property and asymptotic normality property of the proposed estimators.Numerical results indicate that the hierarchically penalized method performs better than some existing methods such as lasso,smoothly clipped absolute deviation(SCAD)and adaptive lasso. 相似文献
146.
Let be a densely defined operator on a Banach space X. Characterizations of when generates a C0‐semigroup on X are known. The famous result of Lumer and Phillips states that it is so if and only if is dissipative and is dense in X for some . There exists also a rich amount of Banach space results concerning perturbations of dissipative operators. In a recent paper Tyran–Kamińska provides perturbation criteria of dissipative operators in terms of ergodic properties. These results, and others, are shown to remain valid in the setting of general non–normable locally convex spaces. Applications of the results to concrete examples of operators on function spaces are also presented. 相似文献
147.
CuO—ZnO/Al2O3—TiO2催化剂中TiO2的结构和电子效应 总被引:6,自引:0,他引:6
采用XPS,XRD,TPR,TPD和指标反应等方法研究了TiO_2在负载型CuO-ZnO/Al_2O_3-TiO_2催化剂中所起的作用.发现TiO_2起双重作用,即结构效应和电子效应,TiO_2的结构效应主要表现为它改善了CuO在载体上的分布.TiO_2的电子效应表现为它对Cu~0具有吸电子的作用,从而削弱了Cu和S之间的吸附力,使S容易脱除.另外,部分还原形成的Ti~(3+)具有促进CuS中的Cu~(2+)还原为Cu~0的能力,TiO_2的上述效应的综合结果使催化剂的抗硫中毒性能大大增强. 相似文献
148.
149.
Let 𝔽 be a field of characteristic two. Let S n (𝔽) denote the vector space of all n?×?n symmetric matrices over 𝔽. We characterize i. subspaces of S n (𝔽) all whose elements have rank at most two where n???3, ii. linear maps from S m (𝔽) to S n (𝔽) that sends matrices of rank at most two into matrices of rank at most two where m, n???3 and |𝔽|?≠?2. 相似文献
150.
By choosing a dynamical system with d different couplings, one can rearrange a system based on the graph with a given vertex dependent on the dynamical system
elements. The relation between the dynamical elements (coupling) is replaced by a relation between the vertexes. Based on
the E
0 transverse projection operator, we addressed synchronization problem of an array of the linearly coupled map lattices of
identical discrete time systems. The synchronization rate is determined by the second largest eigenvalue of the transition
probability matrix. Algebraic properties of the Bose-Mesner algebra with an associated scheme with definite spectrum has been
used in order to study the stability of the coupled map lattice. Associated schemes play a key role and may lead to analytical
methods in studying the stability of the dynamical systems. The relation between the coupling parameters and the chaotic region
is presented. It is shown that the feasible region is analytically determined by the number of couplings (i.e. by increasing
the number of coupled maps, the feasible region is restricted). It is very easy to apply our criteria to the system being
studied and they encompass a wide range of coupling schemes including most of the popularly used ones in the literature.
相似文献