Weak Solutions of Monge-Ampére Type Equations in Optimal Transportation

This paper concerns the weak solutions of some Monge-Ampére type equations in the optimal transportation theory. The relationship between the Aleksandrov solutions and the viscosity solutions of the Monge-Ampére type equations is discussed. A uniform estimate for solution of the Dirichlet problem with homogeneous boundary value is obtained.     

一类二阶迭代微分方程的周期解

利用拓扑度理论研究了一类二阶迭代泛函微分方程x(t) g(x(x(t)))=f(t,x(t),x(t))的周期解的存在性,得出了周期解存在的充分条件.     

EXISTENCE OF WEAK SOLUTIONS OF ORDINARY DIFFERENTIAL EQUATIONS IN BANACH SPACES

0 IntroductionRecently, the study of ordinary differential equations in a Banach spacehas been developed extensively by using the strong topology, see [2],13],[4]. Atpresent, however, there is no reference or paper which systematically studiesweak solutions of the Cauchy problem of ordinary differential equation in theweak topology. In references [l],15],[7] and [8], several results of weak solutionsare proved. In this paper, we shall give the other results of weak solutions,some of which are…     

几种广义非线性发展方程的新解

本文研究了构造了广义Kd V方程和广义KP-Burgers方程等几种广义非线性发展方程的新解的问题.利用三种辅助方程及其新解,获得了广义Kd V方程和广义KP-Burgers方程等几种广义非线性发展方程的新解.这些解由双曲余割函数、双曲正切函数、双曲正割函数、双曲余切函数和余割函数组成.     

WEAK TRAVELLING WAVE FRONT SOLUTIONS OF GENERALIZED DIFFUSION EQUATIONS WITH REACTION

The author demonstrate that the two-point boundary value problem {p′(s)=f′(s)-λp^β(s)for s∈(0,1);β∈(0,1),p(0)=p(1)=0,p(s)>0 if s∈(0,1),has a solution(λ^-，p^-（s）),where |λ^-| is the smallest parameter,under the minimal stringent restrictions on f(s), by applying the shooting and regularization methods. In a classic paper, Kohmogorov et.al.studied in 1937 a problem which can be converted into a special case of the above problem. The author also use the solution(λ^-,p^-(s)) to construct a weak travelling wave front solution u(x,t)=y(ξ),ξ=x-Ct,C=λ^-N/(N+1),of the generalized diffusion equation with reaction δ/δx（k（u）|δu/δx|^n-1 δu/δx)-δu/δt=g（u），where N>0,k(s)>0 a.e.on(0,1),and f(a):=n+1/N∫0ag(t)k^1/N(t)dt is absolutely continuous ou[0,1],while y(ξ) is increasing and absolutely continuous on (-∞,+∞) and (k(y(ξ))|y′(ξ)|^N)′=g(y(ξ))-Cy′(ξ)a.e.on(-∞，+∞）,y(-∞)=0,y(+∞)=1.     

EXISTENCE OF WEAK SOLUTIONS FOR A DEGENERATE GENERALIZED BURGERS EQUATION WITH LARGE INITIAL DATA

11MroduCtlonIn this paper we will investigate the global exlstence ofwe欢 solutions to a de欧nerate辟nerajlzed Bur驴d equatllJll in the formut ＋(。侧。＝t。。。,x E R‘,t＞0(1．1)with the initial data刚,x)一。。卜 卜)(1．1)is not only a means to study hxPerbolic conser、nonl。s[1,2]but also the mathematicalmodel of*the*、 propapatlon offinlt。。plltude sound w。es in、i劝l。area ofduct(see[3;4]),where u is an roustlc vrable,with the linear effects of chang6s!n the duct area taken out;andt I…     

一类非线性双曲偶合方程组广义解的存在性

本文考虑了具有形式ｎ的弱偶合双曲守恒方程组广义解的存在性问题．极大值原理导出了粘性解Ｌ∞模先验估计，关于单个守恒律简化的补偿列紧方法给出了粘性解的收敛性，即广义解的存在性．     

一类矩阵方程的正交对称解及其最佳逼近

1引言设Rn×m表示所有n×m实矩阵集合,I表示单位矩阵,AT表示矩阵A的转置矩阵, ORn×n={P|PTP=I)表示列正交矩阵集,SORn×n={P|PT=P,P2=I}表示对称正交对称矩阵集．如无特别说明,本文中的矩阵P均指这类对称正交对称矩阵．在Rn×m上定义内积为     

不稳定型二阶中立型方程正解的存在性与有界振动

本文研究一类不稳定型二阶中立型微分方程正解的存在性与有界振动．证明了在一定条件下不稳定型二阶中立型方程总存在无界正解，并给出了保证其方程的一切有界解都振动的充分条件，改进了文［１，２］中的有关条件．     

线性规划最优解集的表现

文献［１］讨论了有无穷多最优解的线性规划问题，并利用最优单纯形表格的检验数给出线性规划有无穷多最优解的判别法，本文利用最优基可行解的凸组合及最优极向的非负线性组合给出线性规划最优解集的表现，从而把线性规划最优解集的几何特征阐释清楚．     

非均匀介质中波动方程的部分不变解

讨论了来自于非均匀介质中波动方程的部分不变解的存在性，证明了在波速满足适当的条件下部分不变解是存在的，并得到了部分不变解。     

EXISTENCE AND DECAY OF WEAK SOLUTIONS TO DEGENERATE DAVEY-STEWARTSON EQUATIONS

In this paper, the authors consider a system of degenerate Davey-Stewartson equations. They prove the global existence of weak solutions in some weighted function spaces and the decay of weak solutions in some anisotropic spaces for appropriate initial data.     

VISCOSITY SOLUTIONS OF HJB EQUATIONS ARISING FROM THE VALUATION OF EUROPEAN PASSPORT OPTIONS

The passport option is a call option on the balance of a trading account. The option holder retains the gain from trading, while the issuer is liable for the net loss. In this article, the mathematical foundation for pricing the European passport option is established. The pricing equation which is a fully nonlinear equation is derived using the dynamic programming principle. The comparison principle, uniqueness and convexity preserving of the viscosity solutions of related H J13 equation are proved. A relationship between the passport and lookback options is discussed.     

EXISTENCE AND UNIQUENESS OF WEAK SOLUTIONS FOR TWO-DIMENSIONAL MODIFIED NAVIER-STOKES EQUATIONS

This paper studies a two-dimensional modified Navier-stokes equations. The author shows the existence and uniqueness of weak solutions for this equation by Galerkin method in bounded domains. The result is further extended to the case of unbounded channel-like domains.     

一类复函数方程组的亚纯解

本文研究了一类复函数方程组的亚纯解的存在性问题.利用亚纯函数的Nevanlinna值分布理论,得到了有关方程组的亚纯解变成了有理解的一个主要结论,将复函数方程的某些结果推广至复函数方程组中.     

中立型时滞差分方程的振性与正解存在性

本文研究了一类中立型时滞差分方程的振动性和正解存在性，获得了该方程所有解振动的“Sharp”条件及存在正解的一个充分条件．     

UNIQUENESS OF STATIONARY SOLUTIONS WITH VACUUM OF EULER-POISSON EQUATIONS

In this paper, the uniqueness of stationary solutions with vacuum of Euler-Poisson equations is considered. Through a nonlineax transformation which is a functionof density and entropy the corresponding problem can be reduced to a semilinear ellipticequation with a nonlinear source term consisting of a power function, for which the classical     

ON VERY WEAK SOLUTIONS OF A-HARMONIC EQUATION WITH VERY WEAK BOUNDARY VALUES

1 IntroductionLet fl be a boulided regular domain in n". By regUlar domain we understand any domainof finite measure for which tlie estli11ates fOr Hodge decomposition in (2.6) and (2.7) are justilied.See, fOr example, N, [7], [2]. A Lipscl1tiz dolllain, for example,is regular.We consider solutionsiL Of a quasi1inear second order equation:divA(x, Vu) = 0, (1.1)where A: fl x n" - n" satisfies the usua1 nreasuability conditions(Caratheodory conditions)and that fOr sonle 1 < p < x,the follo…     

PERIODIC SOLUTIONS OF NEUTRAL FUNCTIONAL DIFFERENTIAL EQUATIONS

1 IntroductionThe problem of periodic solutions of nonlineax dtherential equations has been one Of thecenter problem to the tI1eory of differelltial equatiol1, it 11as wide application baCkground(8uchas fOrce oscillatioll of telecomnmnication, periodic euvironment in econondc system, etc.), soit has been a popular subject in the research work. In this paperl we discuss the problem ofperiodic solutions of the fOllowing nolllinear lleutral functional differential equatiollsd,dtD(ft xt) = f(f, …     

一类修正的Navier—Stokes方程组Neumann边值问题的弱解

讨论一类修正的Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ型方程组Ｎｅｕｍａｎｎ边值问题的可解性及解的性质。