BIFURCATION OF LIMIT CYCLE FOR QUADRATIC SYSTEM WITH INVARIANT PARABOLA

In a previous paper, we have proved that a planar quadratic system with invariant parabola Г has at most one limit cycle. In this paper, we use geometric characteristics to give necessary and sufficient conditions under which a PQSГ with three non-degenerate singular points can be transformed into two different definite forms. In this way, we obtain ail the bifurcations of such a system.     

局部Lipschitz连续的伪线性函数的性质

本文使用Clarke次微分分析了定义在Banach空间的局部Lipschitz连续的伪线性函数的性质,并且考虑了伪线性规划解集的性质.     

Global existence and large-time behavior of a parabolic phase-field model with Neumann boundary conditions

In this paper, we continue to study an initial boundary value problems to a model describing the evolution in time of diffusive phase interfaces in sea ice growth. In a previous paper, the global existence and the large-time behavior of weak solutions in one space was studied under Dirichlet boundary conditions. Here, we show that the global existence of weak solutions and the large-time behavior are also studied under Neumann boundary condition. In this paper, we study in space dimension lower than or equal to 3.     

等变示性式和它的积分公式

在[1]中,我们给出了一个黎曼流形的一般示性式的积分公式.本文我们将推广[1]中的结果,从普通上同调论推广到等变上同调论.     

Nearaffine planes

In this paper we develop a theory for nearaffine planes analogous to the theory of ordinary affine translation planes. In a subsequent paper we shall use this theory to give a characterization of a certain class of Minkowski planes.     

Cyclic subspace codes via subspace polynomials

Subspace codes have been intensely studied in the last decade due to their application in random network coding. In particular, cyclic subspace codes are very useful subspace codes with their efficient encoding and decoding algorithms. In a recent paper, Ben-Sasson et al. gave a systematic construction of subspace codes using subspace polynomials. In this paper, we mainly generalize and improve their result so that we can obtain larger codes for fixed parameters and also we can increase the density of some possible parameters. In addition, we give some relative remarks and explicit examples.     

关于二元四次型正定问题的若干注记

§ 1 .　IntroductionInthestudyofdifferentialequationsandothermathematicalandphysicalfields,weoftenneedtodealwiththerootdistributionofanequationandthepositivedefinite,negativedefiniteproblemsofabinaryquarticformsee [2 ,3,4].Itiswellknownthatinthecaseofaquadraticform ,therearemanycriterionsforthepositivedefiniteandnegativeproblems.Forthecaseofabinaryquarticformthestudyonthepositivedefiniteproblemsisfarfromcompletelyunder standing .Thepaper[1]hasdonesomeworksonthisfield.Butitisapitythatthereares…     

Denjoy integral and Henstock-Kurzweil integral in vector lattices,II

In a previous paper we defined a Denjoy integral for mappings from a vector lattice to a complete vector lattice. In this paper we define a Henstock-Kurzweil integral for mappings from a vector lattice to a complete vector lattice and consider the relation between these two integrals.      

A Study of Tate Homology via the Approximation Theory with Applications to the Depth Formula

Acta Mathematica Sinica, English Series - In this paper we are concerned with absolute, relative and Tate Tor modules. In the first part of the paper we generalize a result of Avramov and...     

Further results on large sets of disjoint group-divisible designs

This paper is a continuation of a recent paper by Chen and Stinson, where some recursive constructions for large sets of group-divisible design with block size 3 are presented. In this paper, we give two new recursive constructions. In particular, we apply these constructions in the case of designs where every group has size 2.     

不可约圈与路之并补图的色唯一性

讨论了形如ｋＣＲＵｒＰＲ的一类图的补图的色性．在一定的条件下证明了这类图是色唯一的．本文推广了文［１］的结果．     

Bifurcations in non-autonomous scalar equations

In a previous paper we introduced various definitions of stability and instability for non-autonomous differential equations, and applied these to investigate the bifurcations in some simple models. In this paper we present a more systematic theory of local bifurcations in scalar non-autonomous equations.     

Laws of the single logarithm for delayed sums of random fields II

In an earlier paper we extended Lai's (1974) law of the single logarithm for delayed sums to a class of delayed sums of random fields. In this paper we allow for more general windows.     

Average Impulse Control of Piecewise Deterministic Processes

In this paper, we consider the average impulse control of piecewisedeterministic Markov processes (PDPs). In the first part ofthe paper, we present a policy-iteration technique which consistsof solving a sequence of optimal stopping problems that allowonly a finite number of jumps. In the second part, we presenta discretization of the state space which, along with the techniquementioned above, reduces the average impulse control of PDPsto a sequence of one-dimensional minimizations. A numericalexample is presented.     

Design of space thrusters: a topology optimization problem solved via a Branch and Bound method

In this paper, an exact Branch and Bound Algorithm has been developed to solve a difficult global optimization problem concerning the design of space thrusters. This optimization problem is hard to solve mainly because the objective function to be minimized is implicit and must be computed by using a Finite Element method code. In a previous paper, we implement a method based on local search algorithms and we then proved that this problem is non convex yielding a strong dependency between the obtained local solution and the starting points. In this paper, by taking into account a monotonicity hypothesis that we validated numerically, we provide properties making it possible the computation of bounds. This yields the development of a topology optimization Branch and Bound code. Some numerical examples show the efficiency of this new approach.     

On Well-Posedness and Hausdorff Convergence of Solution Sets of Vector Optimization Problems

In this paper, we refine and improve the results established in a 2003 paper by Deng in a number of directions. Specifically, we establish a well-posedness result for convex vector optimization problems under a condition which is weaker than that used in the paper. Among other things, we also obtain a characterization of well-posedness in terms of Hausdorff distance of associated sets.     

Asymptotic behavior of solutions to a quasilinear nonuniform parabolic system modelling chemotaxis

In this paper, we study a quasilinear nonuniform parabolic system modelling chemotaxis and taking the volume-filling effect into account. The results on the existence of a unique global classical solution was obtained in Cie?lak (2007) [4]. However, the convergence to equilibrium was not considered in that paper. In this paper, we first obtain the crucial uniform boundedness of the solution. Then with the help of a suitable non-smooth Simon-?ojasiewicz approach we obtain the results on convergence to equilibrium and the decay rate.     

增广Lagrangian对偶分解方法求解变分不等式系统

本文考虑带约束的变分不等式系统.提出一个基于增广Lagrangian对偶的分解算法,本文给出了算法的收敛性分析.     

极值分布的一个注记

本文对PH极值分布进行了推广,应用构造相关联的Markov过程的方法,证明了n个相互独立的PH随机变量构成的次序随机变量的分布仍是PH分布。并给出了次序PH随机变量分布表达式的表示方法,本文同时也给出了次序PH随机变量的联合生存分布,本文最后给出了次序PH随机变量在可靠性理论与更新理论中的应用。