SALIMI, Peyman VETRO, Pasquale
Published in
Acta Mathematica Scientia

Recently, Suzuki [T. Suzuki, A generalized Banach contraction principle that characterizes metric completeness, Proc. Amer. Math. Soc. 136 (2008), 1861-1869] proved a fixed point theorem that is a generalization of the Banach contraction principle and characterizes the metric completeness. Paesano and Vetro [D. Paesano and P. Vetro, Suzuki's type c...

DÜUNDAR†, Erdinc ALTAY, Bilal
Published in
Acta Mathematica Scientia

In this article, we prove a decomposition theorem for I2-convergent double sequences and introduce the notions of I2-Cauchy and I*2)-Cauchy double sequence, and then study their certain properties. Finally, we introduce the notions of regularly (I2,I)-convergence and (I2,I)-Cauchy double sequence.

MENG, Yuanyuan WANG, Yanying
Published in
Acta Mathematica Scientia

Let (M, T) be a smooth closed manifold with a smooth involution T whose fixed point set is a disjoint union of an even-dimensional real projective space and a Dold manifold. In some cases, the equivariant bordism classes of (M, T) are determined.

TAN, Qiuheng JIANG, Hangjin DING, Yiming
Published in
Acta Mathematica Scientia

The traditional model selection criterions try to make a balance between fitted error and model complexity. Assumptions on the distribution of the response or the noise, which may be misspecified, should be made before using the traditional ones. In this article, we give a new model selection criterion, based on the assumption that noise term in th...

DENG, Chunyuan
Published in
Acta Mathematica Scientia

This note is to present some results on the group invertibility of linear combinations of idempotents when the difference of two idempotents is group invertible.

WU, Zhaojun
Published in
Acta Mathematica Scientia

The author proves that if f:ℂ→ℂn is a transcendental vector valued meromorphic function of finite order and assume ∑a∈ℂn∪∪{∞}δ(a)=2, then, 1-δ(∞)2-δ(∞)≤K(f′)≤2(1-δ(∞))2-δ(∞), where K(f′)=lim supr→+∞N(r, f′)+N(r, 0, f′)T(r, f′). This result extends the related results for meromorphic function by Singh and Kulkarni.

LIU, Yong QI, Xiaoguang
Published in
Acta Mathematica Scientia

In this article, we investigate the uniqueness problems of difference polynomials of meromorphic functions and obtain some results which can be viewed as discrete analogues of the results given by Shibazaki. Some examples are given to show the results in this article are best possible.

GUO, Wanli XIAO, Haijun CHEN, Shihua
Published in
Acta Mathematica Scientia

This article investigates the consensus problem of the second-order multi-agent systems with an active leader and coupling time delay in direct graph. One decentralized state control rule is constructed for each agent to track the active leader and it is proved that the proposed control scheme enables the consensus to be obtained when the adjacency...

CAO, Haijun LI, Fang ZHANG, Mianmian
Published in
Acta Mathematica Scientia

The main work of this article is to give a nontrivial method to construct pointed semilattice graded weak Hopf algebra from a Clifford monoid S = [Y;Gα, φα,β] by Ore-extensions, and to obtain a co-Frobenius semilattice graded weak Hopf algebra H(S, n, c, χ, a, b) through factoring At by a semilattice graded weak Hopf ideal.

NYAMORADI, Nemat HSU, Tsing-San
Published in
Acta Mathematica Scientia

In this article, we consider a class of degenerate quasilinear elliptic problems with weights and nonlinearity involving the critical Hardy-Sobolev exponent and one sign-changing function. The existence and multiplicity results of positive solutions are obtained by variational methods.