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1.
In this paper, by using the comparing theorem, Razumikhin-type theorem and V-function method, we consider a nonautonomous predator-prey system with stage-structure and time-delay. We get the sufficient conditions for the uniform persistence and the solutions global attractivity of this system. For a periodic system, we obtain the existence and uniqueness of a positive periodic solution of this system. For an almost periodic system, we prove the existence and the uniform asymptotic stability of the almost periodic solutions of this system.  相似文献   

2.
g-Besselian frames in Hilbert spaces   总被引:1,自引:0,他引:1  
In this paper, we introduce the concept of a g-Besselian frame in a Hilbert space and discuss the relations between a g-Besselian frame and a Besselian frame. We also give some characterizations of g-Besselian frames. In the end of this paper, we discuss the stability of g-Besselian frames. Our results show that the relations and the characterizations between a g-Besselian frame and a Besselian frame are different from the corresponding results of g-frames and frames.  相似文献   

3.
In this paper, a class of biholomorphic mappings named quasi-convex mapping of order a in the unit ball of a complex Banach space is introduced. When the Banach space is confined to Cn, we obtain the relation between this class of mappings and the convex mappings. Furthermore, the growth and covering theorems of this class of mappings are given on the unit ball of a complex Banach space X. Finally, we get the second order terms coefficient estimations of the homogeneous expansion of quasi-convex mapping of order a defined on the polydisc in Cn and on the unit ball in a complex Banach space, respectively.  相似文献   

4.
《数学学报》2021,(1):I0001-I0002
Diskcyclicity of Sets of Operators and Applications Mohamed AMOUCH Otmane BENCHIHEB Abstract In this paper,we introduce and study the diskcyclicity and disk transitivity of a set of operators.We establish a diskcyclicity criterion and give the relationship between this criterion and the diskcyclicity.As applications,we study the diskcyclicty of C0-semigroups and C-regularized groups.  相似文献   

5.
罗恩 《计算数学》1980,2(4):383-387
In this paper, the method proposed in [2] is extended to the case of thickplate, the problem in the solution of Reissner model of thick plate is reduced to a solution oftwo displacement functions ω and f, and the general form of the solution of this model isderived. For a simply supported polygonal thick plate, f vanishes identically, and hence therelation between the solution of thick plate and that of similar thin plate can be established.According to this relation, the solutions of a class of thick plates may be derived from thecorresponding solutions of thin plates.  相似文献   

6.
A GENERAL FORM OF THE INCREMENTS OF A TWO-PARAMETER WIENER PROCESS   总被引:2,自引:1,他引:1  
In this paper,we consider a general form of the increments for a two-parameter Wiener process.Both the Csorgo-Revesz‘s increments and a class of the lag increments are the special cases of this general form of increments.Our results imply the theorem that have been given by Csorgo and Revesz(1978),and some of their conditions are removed.  相似文献   

7.
In this paper the boundedness of a derived function of a solution about a class of diffusion variational equations is discussed. The application of it to related stochastic analysis problems is also illustrated. What should be emphasized is that the problem discussed and the ways proved in this paper are fundamentally new and the conclusion of this paper is fairly profound.  相似文献   

8.
In this paper, we analyze the problem of constructing a surface pencil from a given spacelie (timelike) line of curvature. Using the Frenet frame of the given line of curvature in Minkowski 3-space, we express the surface pencil as a linear combination of this frame and derive the necessary and sufficient conditions for the coefficients to satisfy the line of curvature requirement. We illustrate this method by presenting some examples.  相似文献   

9.
In this paper, we've studied distributing characteristic of the paths in these graphs, put forward an idea of the nested rule on path distribution, and established a lat ice algebric structure of a covering of intervals. On the basis of this, we've established the partition theory and a reducible model of hierarchical structure.  相似文献   

10.
陈培慈 《数学季刊》1994,9(3):95-101
In this paper,we define the left rank of a ring R and discuss the relatlons between a left ore reng R and its left classical quotient ring Q on the properties of their ideals and left ranks.Also we gave four equivalent types of the proposition:a ring R has a left classical quotient ring Q and Q is a division ring.As an application of this result,we gave a brief proof method which different from [2] on the theorem of the Goldie Prime rings.  相似文献   

11.
《数学季刊》1995,10(1):97-102
In this paper,we defined a new continuity of supporting function and studyed a new convexity,smoothness of Banach Space and from this we studyed the relations among such convexity,smoothness and differentiability of the norm of Banach Space.  相似文献   

12.
In regularized kernel methods, the solution of a learning problem is found by minimizing a functional consisting of a empirical risk and a regularization term. In this paper, we study the existence of optimal solution of multi-kernel regularization learning. First, we ameliorate a previous conclusion about this problem given by Micchelli and Pontil, and prove that the optimal solution exists whenever the kernel set is a compact set. Second, we consider this problem for Gaussian kernels with variance σ∈(0,∞), and give some conditions under which the optimal solution exists.  相似文献   

13.
The Kirchhoff index Kf(G) of a graph G is defined to be the sum of the resistance distances between all pairs of vertices of G. In this paper, we develop a novel method for ordering the Kirchhoff indices of the complements of trees and unicyclic graphs. With this method, we determine the first five maximum values of Kf■ and the first four maximum values of Kf(ū),where ■ and ū are the complements of a tree T and unicyclic graph U, respectively.  相似文献   

14.
In this work, a Signorini problem with Coulomb friction in two dimensional elasticity is considered. Based on a new representation of the derivative of the double-layer potential, the original problem is reduced to a system of variational inequalities on the boundary of the given domain. The existence and uniqueess of this system are established for a small frictional coefficient. The boundary element approximation of this system is presented and an error estimate is given.  相似文献   

15.
A piecewise algebraic curve is a curve determined by the zero set of a bivariate spline function. In this paper, the Nother type theorems for Cμpiecewise algebraic curves are obtained. The theory of the linear series of sets of places on the piecewise algebraic curve is also established. In this theory, singular cycles are put into the linear series, and a complete series of the piecewise algebraic curves consists of all effective ordinary cycles in an equivalence class and all effective singular cycles which are equivalent specifically to any effective ordinary cycle in the equivalence class. This theory is a generalization of that of linear series of the algebraic curve. With this theory and the fundamental theory of multivariate splines on smoothing cofactors and global conformality conditions, and the results on the general expression of multivariate splines, we get a formula on the index, the order and the dimension of a complete series of the irreducible Cμpiecewise algebraic curves and the degree, the genus and the smoothness of the curves, hence the Riemann-Roch type theorem of the Cμpiecewise algebraic curve is established.  相似文献   

16.
A PREDATOR-PREY SYSTEM WITH STAGE STRUCTURE AND HARVESTING FOR PREDATOR   总被引:2,自引:0,他引:2  
In this paper, we consider a predator-prey system with stage structure and harvesting (where the predator population has two stages, an immature stage and a mature stage with harvesting, and the growth of the prey population is of Lotka-Volterra nature). We obtain the conditions of the globally asymptotic stability for three nonne-gative equilibria of this system.  相似文献   

17.
We describe the relationship between the fuzzy sets and the algebraic hyperstructures. In fact, this paper is a continuation of the ideas presented by Davvaz in (Fuzzy Sets Syst., 117: 477- 484, 2001) and Bhakat and Das in (Fuzzy Sets Syst., 80: 359-368, 1996). The concept of the quasicoincidence of a fuzzy interval value with an interval-valued fuzzy set is introduced and this is a natural generalization of the quasi-coincidence of a fuzzy point in fuzzy sets. By using this new idea, the concept of interval-valued (α,β)-fuzzy sub-hypermodules of a hypermodule is defined. This newly defined interval-valued (α,β)-fuzzy sub-hypermodule is a We shall study such fuzzy sub-hypermodules and sub-hypermodules of a hypermodule. generalization of the usual fuzzy sub-hypermodule. consider the implication-based interval-valued fuzzy  相似文献   

18.
In this paper we consider the class of Bazilevic functions for bi-univalent functions. For this we will estimate the coefficients a2 and a3 using Caratheodory func- tions and the method of differential subordination.  相似文献   

19.
In this paper,it gives the definition of the category of ■-sets and bi-induced maps whose true value set is a Locale,a complete Heyting algebra.In this category it defines the L_b-monomorphisms and the L_b-epimorphisms.Especially,it gives the definition,the judgmental theorem of L_b-coequalizers.Furthermore,it defines L_b-regular epimorphisms and proves the judgmental theorem.At the end it concludes a result:the category of ■-sets and bi-induced maps is finitely cocomplete.  相似文献   

20.
In this paper, we introduce and study a new system of variational inclusions involving (H, η)-monotone operators in Banach space. Using the resolveut operator associated with (H, η)- monotone operators, we prove the existence and uniqueness of solutions for this new system of variational inclusions. We also construct a new algorithm for approximating the solution of this system and discuss the convergence of the iterative sequence generated by the algorithm.  相似文献   

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