A DIRECT SEARCH FRAME-BASED CONJUGATE GRADIENTS METHOD

A derivative-free frame-based conjugate gradients algorithm is presented.Convergenceis shown for C~1 functions,and this is verified in numerical trials.The algorithm is tested ona variety of low dimensional problems,some of which are ill-conditioned,and is also testedon problems of high dimension.Numerical results show that the algorithm is effectiveon both classes of problems.The results are compared with those from a discrete quasi-Newton method,showing that the conjugate gradients algorithm is competitive.Thealgorithm exhibits the conjugate gradients speed-up on problems for which the Hessian atthe solution has repeated or clustered eigenvalues.The algorithm is easily parallelizable.     

THE CONJUGATE POINTS OF CP^∞ AND THE ZEROES OF BERGMAN KERNEL

Two points of the infinite dimensional complex projective space CP∞ with homogeneous coordinates a = （a0, a1, a2, ） and b = （b0, b1, b2, ）, respectively, are conjugate if and only if they are complex orthogonal, i.e., ab = ∞∑j=0 ajbj = 0. For a complete ortho-normal system φ（t） = （φ0（t）, φ1（t）, φ2（t）, ） of L2H（D）, the space of the holomorphic and absolutely square integrable functions in the bounded domain D of Cn, φ（t）, t ∈ D, is considered as the homogeneous coordinate of a point in CP∞. The correspondence t →φ（t） induces a holomorphic imbedding ιφ ： D → CP∞. It is proved that the Bergman kernel K（t, v） of D equals to zero for the two points t and v in D if and only if their image points under ιφ are conjugate points of CP∞.     

Finite Element Method for a Class of Nonliner Problems I-Abstract Results

This paper is devoted to the study of finite dimensional approximation of a class of nonlinear problems. Under some conditions, we show that the approximate solutions are convergent in the cases of branches of nonsingular solutions, limit points and simple bifurcation points. This work establishes     

FAST DENSE MATRIX METHOD FOR THE SOLUTION OF INTEGRAL EQUATIONS OF THE SECOND KIND

We present a fast algorithm based on polynomial interpolation to approximate matrices arising from the discretization of second-kind integral equations where the kernel function is either smooth, non-oscillatory and possessing only a finite number of singularities or a product of such function with a highly oscillatory coefficient function. Contrast to wavelet-like approximations, ourapproximation matrix is not sparse. However, the approximation can be construced in O(n) operations and requires O(n) storage, where n is the number of quadrature points used in the discretization. Moreover, the matrix-vector multiplication cost is of order O(nlogn). Thus our scheme is well suitable for conjugate gradient type methods. Our numerical results indicate that the algorithm is very accurate and stable for high degree polynomial interpolation.     

关于切点单形的两个不等式

Definition Let A_i(i=1,2,…,n+1) be the vertex of a simplex Σ_A in n-dimen-sional Euclidean space Eⁿ and A_i′ be the tangent points which the inscribed sphere of Σ_A is tangent to the side face of Σ_A, then the simplex with the tangent points as vertexes is called the tangent points simplex.     

The Presentation Problem of the Conjugate Cone of the Hardy Space Hp (0 < p ≤ 1)

The Hardy space Hpis not locally convex if 0 < p < 1, even though its conjugate space(Hp) separates the points of Hp. But then it is locally p-convex, and its conjugate cone(Hp) p is large enough to separate the points of Hp. In this case, the conjugate cone can be used to replace its conjugate space to set up the duality theory in the p-convex analysis. This paper deals with the representation problem of the conjugate cone(Hp) p of Hpfor 0 < p ≤ 1, and obtains the subrepresentation theorem(Hp) p L∞(T, C p).     

The generalized regular points and narrow spectrum points of bounded linear operators on Hilbert spaces

In this paper, we introduce the concepts of generalized regular points and narrow spectrum points of bounded linear operators on Hilbert spaces. The concept of generalized regular points is an extension of the concept regular points, and so, the set of all spectrum points is reduced to the narrow spectrum. We present not only the same and different properties of spectrum and of narrow spectrum but also show the relationship between them. Finally, the well known problem about the invariant subspaces of bounded linear operators on separable Hilbert spaces is simplified to the problem of the operator with narrow spectrum only.     

A MPI PARALLEL PRECONDITIONED SPECTRAL ELEMENT METHOD FOR THE HELMHOLTZ EQUATION

Spectral element method is well known as high-order method, and has potential better parallel feature as compared with low order methods. In this paper, a parallel preconditioned conjugate gradient iterative method is proposed to solving the spectral element approximation of the Helmholtz equation. The parallel algorithm is shown to have good performance as compared to non parallel cases, especially when the stiffness matrix is not memorized. A series of numerical experiments in one dimensional case is carried out to demonstrate the efficiency of the proposed method.     

SOME METRIC AND TOPOLOGICAL PROPERTIES OF NEARLY STRONGLY AND NEARLY VERY CONVEX SPACES

We obtain characterizations of nearly strong convexity and nearly very convexity by using the dual concept of S and WS points, related to the so-called Rolewicz's property(α). We give a characterization of those points in terms of continuity properties of the identity mapping. The connection between these two geometric properties is established, and finally an application to approximative compactness is given.     

进位吸引子与拓扑熵

Let M be a manifold (possibly with boundary), and f:M→M be continuous. Call a closed invariant set A包含M an adic attractor of f if it attracts almost all points (in the sense of Lebesgue measure) and the restriction f|A is topologically conjugate to an adic system. Such an attractor A is called n-adic if the restriction flA can be topologically conjugate the n-adic system.     

Structure of the spectrum of infinite dimensional Hamiltonian operators

This paper deals with the structure of the spectrum of infinite dimensional Hamiltonian operators.It is shown that the spectrum,the union of the point spectrum and residual spectrum,and the continuous spectrum are all symmetric with respect to the imaginary axis of the complex plane. Moreover,it is proved that the residual spectrum does not contain any pair of points symmetric with respect to the imaginary axis;and a complete characterization of the residual spectrum in terms of the point spectrum is then given.As applications of these structure results,we obtain several necessary and sufficient conditions for the residual spectrum of a class of infinite dimensional Hamiltonian operators to be empty.     

Adic Attractor and Topological Entropy

1 IntroductionLet M be a manifold (possibly with boundary), and F : M → M be continuous. Call a closed invariant set A (?) M an adic attractor of f if it attracts almost all points (in the sense of Lebesgue measure) and the restriction f|A is topologically conjugate to an adic system. Such an attractor A is called n-adic if the restriction f|A can be topologically conjugate the n-adic system.     

AN UPPER BOUND ON AVERAGE TOUCHING NUMBER OF A VORONOI PARTITION

A Voronoi partition is decided bythe configurations of N centerepoints in n dimensional Euclidean space. The total number of nearest neighbor points for a given centerpoint in the partition is called its touching number. It is shown that the average touching number for all points in a Voronoi partition is not greater than the n dimensional kissing number, that is, the maximum uumber of unit spheres that can touch a given unit sphere without overlapping.     

Partial Regularity of Suitable Weak Solutions to the System of the Incompressible Shear-thinning Flow

This paper is devoted to the partial regularity of suitable weak solutions to the system of the incompressible shear-thinning flow in a bounded domainΩ■Rⁿ,n≥2.It is proved that there exists a suitable weak solution of the shear-thinning fluid in the n-D smooth bounded domain(for n≥2).For 3 D model,it is proved that the singular points are concentrated on a closed set whose 1 dimensional Hausdorff measure is zero.     

A Level Set Representation Method for N-Dimensional Convex Shape and Applications

In this work,we present a new method for convex shape representation,which is regardless of the dimension of the concerned objects,using level-set approaches.To the best of our knowledge,the proposed prior is the first one which can work for high dimensional objects.Convexity prior is very useful for object completion in computer vision.It is a very challenging task to represent high dimensional convex objects.In this paper,we first prove that the convexity of the considered object is equivalent to the convexity of the associated signed distance function.Then,the second order condition of convex functions is used to characterize the shape convexity equivalently.We apply this new method to two applications:object segmentation with convexity prior and convex hull problem(especially with outliers).For both applications,the involved problems can be written as a general optimization problem with three constraints.An algorithm based on the alternating direction method of multipliers is presented for the optimization problem.Numerical experiments are conducted to verify the effectiveness of the proposed representation method and algorithm.     

A New by the Characterization of Mobius Transformations Use of Apollonius Points of （2n-1）-gons

In this paper, we give a new characterization of Mobius transformations. To do this, we extend the notion of Apollonius points of a triangle and of a pentagon, to the notion of Apollonius points of an arbitrary （2n-1）-gon.     

Semi inherited bivariate interpolation

The bivariate interpolation in two dimensional space R2 is more complicated than that in one dimensional space R, because there is no Haar space of continuous functions in R2. Therefore, the bivariate interpolation has not a unique solution for a set of arbitrary distinct pairwise points. In this work, we suggest a type of basis which depends on the points such that the bivariate interpolation has the unique solution for any set of distinct pairwise points. In this case, the matrix of bivariate interpolation has the semi inherited factorization.     

求解一类广义Nash均衡问题

Generalized Nash equilibrium problem (GNEP) is an important model that has many applications in practice. However, a GNEP usually has multiple or even infinitely many Nash equilibrium points and it is not easy to choose a favorable solution from those equilibria. This paper considers a class of GNEP with some kind of separability. We first extend the so-called normalized equilibrium concept to the stationarity sense and then, we propose an approach to solve the normalized stationary points by reformulating the GNEP as a single optimization problem. We further demonstrate the proposed approach on a GNEP model in similar product markets.     

三角形数表的性质及其应用

The calculation of the number of relations on a finite set is interesting,it is related to the world famous question “the number of topology on n”.In this paper,we discussed the relation between the numbers of a curve triangle number table,it is similar to Pascal triangle,gave the number of solutions of infinite equation(*)and obtained the new combination meaning of Catalan number;similar to the second class Striling number,it is the number of equivalent class of a relation.     

Invariant properties of representations under cleft extensions

The main aim of this paper is to give the invariant properties of representations of algebras under cleft extensions over a semisimple Hopf algebra. Firstly, we explain the concept of the cleft extension and give a relation between the cleft extension and the crossed product which is the approach we depend upon. Then, by making use of them, we prove that over an algebraically closed field k, for a finite dimensional Hopf algebra H which is semisimple as well as its dual H*, the representation type of an algebra is an invariant property under a finite dimensional H-cleft extension . In the other part, we still show that over an arbitrary field k, the Nakayama property of a k-algebra is also an invariant property under an H -cleft extension when the radical of the algebra is H-stable.