On Existence for Polynomial-Like Iterative Equations

Many known results on the iterative equation α_i=1 ⁿ λ_i?ⁱ(x) = F(x) require a condition that λ₁ > 0 for technical reasons. A problem on the existence of solutions of this iterative equation with the natural restriction λ_n ≠ 0 is raised. In this paper we study an auxiliary functional equation for its invertible solutions. Then we apply our results on the auxiliary equation to solve the problem in some cases.     

Elementary aspects ofB p,q s (Kn) andF p,q s (Kn) spaces

In the first part of this paper, we discuss some properties of S^Ω(K_n), L _P ^Ω (K_n) and L _P ^Ω (K_n;l_q) spaces, give the Plancherel-Polya-Nikol’skij type inequalities and some multiplier theorems. In the second part of this paper, using the results of Part I we prove some preliminary results for the spaces B _p,q ^s (K_n) and F _p,q ^s (K_n).     

Approximation of Nearest Common Fixed Point of Nonexpansive Mappings in Hilbert Spaces

The purpose of this paper is to study the convergence problem of the iteration scheme xn＋l = λn＋1y ＋ （1 - λn＋1）Tn＋1xn for a family of infinitely many nonexpansive mappings T1, T2,... in a Hilbert space. It is proved that under suitable conditions this iteration scheme converges strongly to the nearest common fixed point of this family of nonexpansive mappings. The results presented in this paper extend and improve some recent results.     

Ranks of the common solution to six quaternion matrix equations

A new expression is established for the common solution to six classical linear quaternion matrix equations A 1 X = C 1 , X B 1 = C 3 , A 2 X = C 2 , X B 2 = C 4 , A 3 X B 3 = C 5 , A 4 X B 4 = C 6 which was investigated recently by Wang, Chang and Ning (Q. Wang, H. Chang, Q. Ning, The common solution to six quaternion matrix equations with applications, Appl. Math. Comput. 195: 721-732 (2008)). Formulas are derived for the maximal and minimal ranks of the common solution to this system. Moreover, corresponding results on some special cases are presented. As an application, a necessary and sufficient condition is presented for the invariance of the rank of the general solution to this system. Some known results can be regarded as the special cases of the results in this paper.     

On the Homology and Fiber Cone of Ideals

In this article, we give a unified approach for several results concerning the fiber cone. Our novel idea is to use the complex C(x _k , ? _{I 1; I 2} , (1, n)). We improve earlier results obtained by several researchers and get some new results. We give a more general definition of ideals of minimal multiplicity and of ideals of almost minimal multiplicity. We also compute the Hilbert series of the fiber cone for these ideals.     

On n-widths of some periodic convolution classes in Orlicz spaces

In this paper we extend the some accurate results on n-width of Sobolevclass W_∞~γ in L_p spaces to Orlicz spaces,and establish the correspondingresults for dual cases.     

Longest paths and cycles in K1,3-free graphs

In this article we show that the standard results concerning longest paths and cycles in graphs can be improved for K_1,3-free graphs. We obtain as a consequence of these results conditions for the existence of a hamiltonian path and cycle in K_1,3-free graphs.     

Classification of Simple C-Algebras: Inductive Limits of Matrix Algebras Over One-Dimensional Spaces

In this article, we will give a complete classification of simple C^*-algebras which can be written as inductive limits of algebras of the form A_n=⊕_i=1^k_nM_[n,i](C(X_n,i)), where X_n,i are arbitrary variable one-dimensional compact metrizable spaces. The results unify and generalize the previous results for the case X_n,i=S¹ and for the case of X_n,i being trees. We obtain our classification results by reducing the case of general one-dimensional spaces to the case of circles. The techniques in this paper play important roles in the study of the case of higher-dimensional spaces.     

Constrained l1 estimation via geometric programming

The l₁ and constrained l₁ estimation problems are viewed in the light of extended geometric programming. As a result of this point of view we are able to establish an equivalence between geometric and linear programming duality results for these classes of problems. In addition, the duality results provide some useful insights into the properties of the l₁ estimation problems. Finally we establish an equivalence between the l_∞ norm problem and a class of constrained l₁ estimation problems.     

On generalized <Emphasis Type="Italic">R</Emphasis><Subscript>0</Subscript> and <Emphasis Type="Italic">R</Emphasis><Subscript>1</Subscript> spaces

Characterizations of some properties of generalized R ₀ and R ₁ topological spaces by using closure operator defined on a generalized topological space will be given. It is also shown that many results done in this area in some previous papers can be considered as special cases of our results.     

非线性算子具误差的隐迭代程序的强收敛性

设K是一致凸Banach空间中的非空闭凸子集,T_i:K→K(i=1,2,…,N)是有限族完全渐近非扩张映象.对任意的x_0∈K,具误差的隐迭代序列{x_n}为:x_n=α_nx_n-1+β_nT_n~kx_n+γ_nu_n,n≥1,其中{α_n},{β_n},{γ_n}■[0,1]满足α_n+β_n+γ_n=1,{u_n}是K中的有界序列.在一定的条件下,该文建立了隐迭代序列{x_n}的强收敛性.得到隐迭代序列{x_n}强收敛于有限族完全渐近非扩张映象公共不动点的充要条件.所得结果改进和推广了Shahzad与Zegeye,Zhou与Chang,Chang,Tan,Lee与Chan等人的相应结果.     

The cardinals below

The results of this paper concern the effective cardinal structure of the subsets of [ω₁]^<ω₁, the set of all countable subsets of ω₁. The main results include dichotomy theorems and theorems which show that the effective cardinal structure is complicated.     

On some kinds of fuzzy connected spaces

In this paper we introduce new results in fuzzy connected spaces. Among the results obtained we can mention the good extension of local connectedness. Also we prove that in a T ₁-fuzzy compact space the notions c-zero dimensional, strong c-zero dimensional and totally c_i-disconnected are equivalent.     

Comment on “Finite-time H∞ control for linear continuous system with norm-bounded disturbance”

This note addresses a defect occurring in “Finite-time H_∞ control for linear continuous system with norm-bounded disturbance”, which can’t ensure the system H_∞ finite-time bounded with a prescribed noise attenuation level γ. The corrected results and new simulation results are given in this note.     

Separation in topological algebras

One of the basic results from the theory of topological groups is that aT ₀ topological group is already completely regular. It is also known [1] thatT ₀ quasigroups are regular. Taylor [8] showed that a fragment of these results holds in any congruence permutable variety, namely that in such a variety aT ₀ topological algebra is already Hausdorff. Gumm [2] extended this result to 3-permutable varieties and showed that, more generally,T ₀ topological algebras in congruencen-permutable varieties areT ₁. In this paper we show thatT ₀ topological algebras inn-permutable varieties satisfy a separation condition strictly stronger thanT ₁. We also give some counterexamples that show that some of these separation results are the best possible.Presented by S. Burris.This research was part of the author's thesis at The University of Colorado, directed by Walter Taylor. The author wishes to thank professor Taylor for his many contributions.     

SOLITON SOLUTION OF NONLINEAR SCHRODINGER EQUATION WITH HIGHER ORDER DISPERSION TERMS

It is shown in this paper that if parameters β1,β2 and β3 of a nonlinear Schrodinger equation with higher order dispersion terms (HNLS) satisfy the condition: 6β1-β2-2β3(1- 6β1k)= 0, k a real constant, then the fundamental soliton solutions of the HNLS equation exist. The exact soliton solutions are given and the relation between this condition and the known results inthe literature is also discussed.     

A cycle lemma for permutation inversions

In this paper we study some properties of the inversion statistic. Some enumerative results concerning the permutations of the multiset {x₁^m₁,x₂^m₂} with respect to the inversion parameter are established and it is shown that these depend on gcd(m₁,m₂). Using a “cycle lemma”, a combinatorial proof of the results is given. Moreover, some applications to the Gaussian binomial coefficient are illustrated.     

脉冲耦合时滞微分与连续差分系统的稳定性

该文研究脉冲耦合时滞微分与连续差分系统的稳定性.首先,该文为这类系统引入了一些新的概念如L_2稳定、吸引和L_2渐近稳定,然后给出了一些系统L_2稳定和L_2渐近稳定的判据.该文也给出了一个例子来验证所得结论的有效性.应该注意到这是首次考虑这类脉冲系统.     

Asymptotic expansions of the zeta-determinants of Dirac Laplacians on a compact manifold with boundary

In this article we discuss the asymptotic expansions of the zeta-determinants of Dirac Laplacians on a compact manifold with boundary when the boundary part is stretched. In [12] the author studied the same question under the assumption of no existence of L² - and extended L² -solutions of Dirac operators when the boundary part is stretched to infinite length. Therefore, the results in this article generalize those in [12]. Using the main results we obtain the formula describing the ratio of two zeta-determinants of Dirac Laplacians with the APS boundary conditions associated with two unitary involutions σ₁ and σ₂ on ker B satisfying Gσ_i = -σ_i G. We also prove the adiabatic decomposition formulas for the zeta-determinants of Dirac Laplacians on a closed manifold when the Dirichlet or the APS boundary condition is imposed on partitioned manifolds, which generalize the results in [10] and [11].     

Vertex-transitive graphs: Symmetric graphs of prime valency

Let G be a group acting symmetrically on a graph Σ, let G₁ be a subgroup of G minimal among those that act symmetrically on Σ, and let G₂ be a subgroup of G₁ maximal among those normal subgroups of G₁ which contain no member except 1 which fixes a vertex of Σ. The most precise result of this paper is that if Σ has prime valency p, then either Σ is a bipartite graph or G₂ acts regularly on Σ or G₁ | G₂ is a simple group which acts symmetrically on a graph of valency p which can be constructed from Σ and does not have more vertices than Σ. The results on vertex-transitive groups necessary to establish results like this are also included.