首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The earliest paper to study boundary behavior of the integrals of the Cauchy-Martinelli type was[1]. But up to the present, not many boundary behaviors for the integrals of the Cauchy-Fantappi type are discussed. In this paper, we study the boundary behavior for the following form  相似文献   

2.
§ 1 Introduction and setting of the problemThe optimal control of age-dependent population dynamics has been intensivelystudied in the last two decades and there is now a vast stock of literature on the topic ofoptimal control problems ofage-structured population dynamics.(see [1 -9] ) .To the bestof our knowledge,the works of Brokate[3,4] are the firstto deal with this topic.Since then,many authors devote to the optimal harvesting problem.In this aspect,we refere to thefundamental papers o…  相似文献   

3.
Define two operators In and It,the inner product operator In(g)(x) := j∈Zs(g,f(·-j))f(x-j) and the interpolation operator It(g)(x) := j∈Zs g(j)f(x-j),where f belongs to some space and integer s 1.We call f the generator of the operators In and It.It is well known that there are many results on operators In and It.But there remain some important problems to be further explored.For application we first need to find the available generators (that can recover polynomials as It(p) = p or In(p) = p,p ∈Πm-1) for constructing the relative operators.In this paper,we focus on the available generator in the class of spline functions.We shall see that not all spline functions can be used to construct available generators.Fortunately,we do find a spline function in S,of degree m-1,where m is even and S is a class of splines.But for odd m the problem is still open.Results on spline functions in this paper are new.  相似文献   

4.
§1IntroductionThe generalized Ball curves possess many properties similar to the properties of Béziercurve and an advantage that there are more efficient elevation and recursive algorithms forevaluating the points on curve[1-3].The dual functionals are an important tool forconversing various bases and studying the properties of curve and surface.Lai gave thedual functionals of polynomials in B-form or in Bézier form over a simplex[4].In theunivariate setting the dual functionals of variou…  相似文献   

5.
It is well known,that in the theory of stability in differential equations,Liapunov's second method may be the most important The center problem of Liapunov's second method is construction of Liapunov function for concrete problems.Beyond any doubt,construction of Liapunov functions is an art.In the case of functional differential equations,there were also many attempts to establish various kinds of Liapunov type theorems.Recently Burton[2]presented an excellent theorem using the Liapunov functional to solve the asymptotic stability of functional differential equation with bounded delay. However,the construction of such a Liapunov functional is still very hard for concrete problems. In this paper, by utilizing this theorem due to Burton,we construct concrete Liapunov functional for certain and nonlinear delay differential equations and derive new sufficient conditions for asymptotic stability.Those criteria improve the result of literature[1]and they are with simple forms,easily checked and applicable.  相似文献   

6.
In this paper,we observe a special kind of continuous functions on graphs.By estimating the integrals of these functions,we prove that there are no sensitive commutative group actions on graphs.Furthermore,we consider a 1-dimensional continuum composed of a spiral curve and a circle and show that there exist sensitive homeomorphisms on it,which answers negatively a question proposed by Kato in 1993.  相似文献   

7.
Nonlinear Schrodinger equation (NSE) arises in many physical problems. It is a very important equation. A lot of works studied the wellposed, the existence of solution of NSE etc. And there are many works studied the numerical methods for it. Recently, since the development of infinite dimensional dynamic system the dynamical behavior of NSE has been investigated. The paper [1] studied the long time wellposedness, the existence of universal attractor and the estimate of Lyapunov exponent for NSE with weakly damped. At the same time it was need to study the large time new computational methods and to discuss its convergence error estimate, the existence of approximate attractors etc. In this pape we study the NSE with weakly damped (1.1). We assume,where 0<λ<2 is a constant. If we wish to construct the higher accuracy computational scheme, it will be difficult that staigh from the equation (1.1). Therefore we start with (1. 4) and use fully discrete Fourier spectral method with time difference to disscus  相似文献   

8.
In this paper, a new high accuracy numerical method for the thin-film problems of micron and submicron size ferromagnetic elements is proposed. For the computation of stray field, we use the finite element method(FEM) by introducing a semi-discrete artificial boundary condition [1, 2]. In our numerical experiments about the domain patterns and their movement, we can see that the results are accordant to that of experiments and other numerical methods. Our method are very convenient to deal with arbitrary shape of thin films such as a polygon with high accuracy.  相似文献   

9.
We prove two extension theorems of Ohsawa-Takegoshi type on compact Khler manifolds.In our proof,there are many complications arising from the regularization process of quasi-psh functions on compact Khler manifolds,and unfortunately we only obtain particular cases of the expected result.We remark that the two special cases we proved are natural,since they occur in many situations.We hope that the new techniques we develop here will allow us to obtain the general extension result of Ohsawa-Takegoshi type on compact Khler manifolds in a near future.  相似文献   

10.
Some activities of applied mathematics are seen from different angles in a two-part series. In part 1, we will emphasize on mathematical modeling, exponential prediction models. On a systemic construction of the quantitative mathematics,it is shown that there is an impassible chasm between pure and applied mathematics, that existance and structures of systems are independent of human consciousness. For the purpose of prediction, concepts of calculus are generalized to discrete time series.  相似文献   

11.
We study the doubling property of binomial measures on generalized ternary Cantor subsets of [0, 1]. We find some new phenomena. There are three different cases. In the first case, we obtain an equivalent condition for the measure to be doubling. In the other cases, we show that the condition is not necessary. Then facts and partial results are discussed.  相似文献   

12.
In this paper,a new high accuracy numerical method for the thin-film problems of micron and submicron size ferromagnetic elements is proposed,For the computaion of stray field,we use the finite element method(FEM) by introducing a semi-discrete artificial boundary condition [1,2],In our numerical experiments about the domain patterns and their movement,we can see that the results are accordant to that of experments and other numerical methods.Our method are very conveient to deal with arbitrary shape of thin films such as a polygon with high accuracy.  相似文献   

13.
1. Introduction Concerning the finite element analysis for linear and nonlinear parabolic equa tions there are a lot of papers, however, only a few of them devoted to the parabolic problems with mixed boundary conditions. In[1],[2] and [3], the finite element methods for some non-linear parabolic problems are systematically considered, but they are mainly restriced to the cases in which the boundary conditions are of Dirichlet  相似文献   

14.
Noether's theorem is generalized to the theory of coupled fields with parameters in this paper. Considering that many problems in continuum mechanics have Lagrange densities which are linear combinations of convolution integrals on a parameter of their arguments, the condition of stationary value of these functionals is discussed. Following the thought of Noether's theorem, the author reveals some relations among the invariants of the functionals mentioned above under a family of infinitesimal transformations, variational principles and conservation laws. In addition, two conservation laws for thermo-elasticity are established.  相似文献   

15.
In this paper, the authors discuss a class of multilinear singular integrals and obtain that the operators are bounded from H^1(R^n) to weak L^1(R^n). Using this result, we can directly prove a main theorem in [5].  相似文献   

16.
In this paper, we study a class of ruin problems, in which premiums and claims are dependent. Under the assumption that premium income is a stochastic process, we raise the model that premiums and claims are dependent, give its numerical characteristics and the ruin probability of the individual risk model in the surplus process. In addition, we promote the number of insurance policies to a Poisson process with parameter λ, using martingale methods to obtain the upper bound of the ultimate ruin probability.  相似文献   

17.
In this paper, we describe a method to solve large-scale structural optimization problems by sequential convex programming (SCP). A predictor-corrector interior point method is applied to solve the strictly convex subproblems. The SCP algorithm and the topology optimization approach are introduced. Especially, different strategies to solve certain linear systems of equations are analyzed. Numerical results are presented to show the efficiency of the proposed method for solving topology optimization problems and to compare different variants.  相似文献   

18.
In this work we introduce two new Barzilai and Borwein-like steps sizes for the classical gradient method for strictly convex quadratic optimization problems.The proposed step sizes employ second-order information in order to obtain faster gradient-type methods.Both step sizes are derived from two unconstrained optimization models that involve approximate information of the Hessian of the objective function.A convergence analysis of the proposed algorithm is provided.Some numerical experiments are performed in order to compare the efficiency and effectiveness of the proposed methods with similar methods in the literature.Experimentally,it is observed that our proposals accelerate the gradient method at nearly no extra computational cost,which makes our proposal a good alternative to solve large-scale problems.  相似文献   

19.
Let G be a nontrivial connected and vertex-colored graph. A subset X of the vertex set of G is called rainbow if any two vertices in X have distinct colors. The graph G is called rainbow vertex-disconnected if for any two vertices x and y of G, there exists a vertex subset S of G such that when x and y are nonadjacent, S is rainbow and x and y belong to different components of G-S; whereas when x and y are adjacent, S + x or S + y is rainbow and x and y belong to different components of(G-xy)-S. For a connected graph G, the rainbow vertex-disconnection number of G, denoted by rvd(G), is the minimum number of colors that are needed to make G rainbow vertexdisconnected. In this paper, we characterize all graphs of order n with rainbow vertex-disconnection number k for k ∈ {1, 2, n}, and determine the rainbow vertex-disconnection numbers of some special graphs. Moreover, we study the extremal problems on the number of edges of a connected graph G with order n and rvd(G) = k for given integers k and n with 1 ≤ k ≤ n.  相似文献   

20.
Geometry of Multinomial Distribution Models   总被引:2,自引:0,他引:2  
In this paper, we present a new differential geometric framework to study mul-tinomial distribution models in which a p-vector parameter θ is of interest. Thegeometry and models discussed here are different from those of Efron and Amari(EA) and Bates and Watts (BW). In brief, the models we study are close to thoseof EA and the geometry we present is close to that of BW. We try to combine bothEA and BW advantages into our models. Suppose that Y = (y_1,…,y_n)~T are multinomial random variables whose densityfunction has the form  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号