高维格上时滞反应扩散方程的行波解

本文利用Schauder不动点定理和上、下解技术,研究了高维格上时滞反应扩散方程组当非线性项满足拟单调条件、指数拟单调条件、部分拟单调条件以及部分指数拟单调条件时行波解的存在性.     

时滞格微分方程组的行波解

文利用Schauder不动点定理的方法和上、下解技巧,研究了时滞格微分方程组的行波解,给出了当系统的非线性项满足"拟单调条件"和"指数拟单调条件"时行波解的存在性.     

状态依赖时滞非局部扩散方程的波前解

本文主要研究状态依赖时滞非局部扩散方程的波前解,当出生函数单调时,可以得到单调行波解的存在性和非存在性,然后,由先验估计和Ikehara定理,进一步得到临界波前解的渐近性;当出生函数非单调时,通过引进两个辅助拟单调方程,也可以得到相应非拟单调条件下的存在性结果.     

抽象锥中积分—微分方程的耦合拟解及单调迭代方法

本文利用微分方程、积分方程的耦合上、下拟解 ,借助于单调迭代法 ,讨论了非线性 Volterra型积分—微分方程的耦合极拟解问题     

Banach空间阻尼弹性系统L-拟mild解的存在性

该文讨论了Banach空间中具有阻尼弹性系统L-拟mild解的存在性.这些结果改进和推广了一些相关的结论在常微分方程和偏微分方程方面.在非线性项满足单调条件和非紧性测度条件下,获得了该问题极大mild解的存在性.另外,给出例子说明该结果的可行性.     

弱广义向量拟似变分不等式解的存在性

研究拓扑向量空间上弱广义向量拟似变分不等式解的存在性问题.与Khaliq和Rashid等在单调或伪单调假设条件下,利用KKM定理证明解的存在性不同,在集值映射是非空凸值映射并且有开下截口的条件下,利用Fan-Browder不动点原理证明解的存在性.     

Banach空间非线性发展方程的耦合周期解

本文利用上下解方法与正算子半群理论,讨论了Banach空间中具有混合单调（混拟单调）性质的非线性发展方程耦合周期解的存在性及周期解的存在唯一性,所得结果概括并推广了有关常微分方程和偏微分方程的若干结论．     

一类具时间周期和非局部时滞的非拟单调反应扩散方程的整体解

研究了一类不具有拟单调性的时间周期非局部时滞反应扩散方程的新型整体解.为了克服拟单调性条件缺失带来的困难,借助于两个拟单调辅助方程的周期行波解和相应空间齐次方程的全轨道构造了新型的整体解.     

Banach空间非线性二阶微分积分方程初值问题的单调迭代方法

利用单调迭代方法及Mnch不动点定理,研究了Banach空间中混合单调二阶微分积分方程初值问题的耦合最小最大拟解及解的存在性,给出了耦合最小最大拟解及解的存在定理.     

Banach空间二阶周期边值问题的一种拟上下解方法

利用比较结果,通过构造L-拟上下解的单调迭代过程,在L-拟上下解反序的情形下,研究了Banach空间二阶周期边值问题解的存在性,并获得该问题解的存在性与唯一性结果.     

Error Bounds for Nonnegative Dynamic Models

The extension of Markov reward models to dynamic models with nonnegative matrices is motivated by practical applications, such as economic input–output, employment, or population models. This paper studies the generalization of error bound theorems for Markov reward structures to dynamic reward structures with arbitrary nonnegative matrices. Both irreducible and reducible matrices are covered. In addition, results for the stochastic case are unified and extended. First, generalized expressions are derived for average reward functions. The special normalization case is distinguished and is shown to be transformable into the stochastic case. Its interpretation is of interest in itself. Next, error bound results are studied. Under a general normalization condition, it is shown that the results for the stochastic case can be extended. Both the average case and the transient case are included. A random walk-type example is included to illustrate the results.     

相同模式内弧立波的强斜相互作用*

水文讨论分层流体中相同模式向孤立波的强斜相互作用,包括浅流体情形和深流体情形．采用Lazrange描述方法,发现在浅流体情形相互作用由KP方程描述;在深流体情形相互作用由二维的中等长波方程描述;在无限深情形相互作用由二维的BO方程描述．     

Strong limit point criteria for a class of singular discrete linear Hamiltonian systems

This paper is concerned with the limit point case for a class of singular discrete linear Hamiltonian systems. The limit point case is divided into the strong and the weak limit point cases. Several sufficient conditions for the strong limit point case are established. In consequence, two criteria of the strong limit point case for second-order formally self-adjoint vector difference equations are obtained.     

Progressive censoring from heterogeneous distributions with applications to robustness

Progressively censored order statistics from heterogeneous distributions are introduced and their properties are investigated. After deriving the joint density function, some properties are established. In particular, the case of proportional hazards leads to an interesting connection to the model of generalized order statistics. Finally, the special case of exponential distribution is considered and some known results are generalized to this heterogeneous case, and their implications to robustness are highlighted.     

On the weak discontinuity surfaces and tapes of equation systems in fluid mechanics

The weak discontinuity surfaces for a system of quasi-linear differential equations of higher order are developed. The classification of equation systems in fluid mechanics is based on the propagative weak discontinuity surfaces. Types of equations for different flow models are discussed. The conclusion is as follows:(a) For incompressible nonviscous flow, incompressible viscous flow and compressible viscous flow, the types of equations are all parabolic in the unsteady case and elliptic in the steady case.(b) For compressible nonviscous flow, the type of equations is hyperbolic in the unsteady case or steady supersonic case, and the type is elliptic in the steady subsonic case.     

Nonlinear three-point boundary value problems

In the present work, we investigate nonlinear three-point boundary value problems (second-order differential equations with boundary conditions imposed at three consecutive points) in an effort to understand the conditions that must be imposed upon nonlinear perturbations of a linear problem in order to obtain a solution of a three-point problem. Both the noncritical case and the critical case are considered. In the first case, existence and uniqueness results are obtained, and in the second case we deal with local bifurcation problems when the nonlinearities are quadratic and cubic.     

Interpolation error estimates of a modified 8-node serendipity finite element

Summary. Interpolation error estimates for a modified 8-node serendipity finite element are derived in both regular and degenerate cases, the latter of which includes the case when the element is of triangular shape. For defined over a quadrilateral K, the error for the interpolant is estimated as , where in the regular case and in the degenerate case, respectively. Thus, the obtained error estimate in the degenerate case is of the same quality as in the regular case at least for . Results for some related elements are also given. Received June 2, 1997 / Published online March 16, 2000     

信息不完备条件下地震应急案例结构化方法研究

地震突发事件具有紧迫性、破坏性和信息不完备性,给人民群众生命财产安全造成了重大危害。案例推理是处置突发事件的有效方法。其中,案例表示是案例推理的基础,但是目前的案例表示方法并没有考虑突发事件的信息不完备性。这削弱了突发事件应急案例表示效果,并影响案例检索的准确性和案例适配的效果。本文在研究案例表示方法的基础上,结合案例推理的结构化和定量化需求,将证据理论的基本信任分配函数引入框架表示法中,提出了信息不完备条件下地震应急案例的框架表示法。接下来,本文提出了信息不完备条件下地震应急案例检索方法。最后,文章对提出的信息不完备条件下地震应急案例的结构化方法进行了应用验证。     

Global well-posedness of coupled parabolic systems

The initial boundary value problem of a class of reaction-diffusion systems(coupled parabolic systems)with nonlinear coupled source terms is considered in order to classify the initial data for the global existence,finite time blowup and long time decay of the solution.The whole study is conducted by considering three cases according to initial energy:the low initial energy case,critical initial energy case and high initial energy case.For the low initial energy case and critical initial energy case the sufficient initial conditions of global existence,long time decay and finite time blowup are given to show a sharp-like condition.In addition,for the high initial energy case the possibility of both global existence and finite time blowup is proved first,and then some sufficient initial conditions of finite time blowup and global existence are obtained,respectively.     

Coupled Continuous Time Random Maxima

Continuous Time Random Maxima (CTRM) are a generalization of classical extreme value theory: Instead of observing random events at regular intervals in time, the waiting times between the events are also random variables which have arbitrary distributions. In case that the waiting times between the events have infinite mean, the limit process that appears differs from the limit process that appears in the classical case. With a continuous mapping approach, we derive a limit theorem for the case that the waiting times and the subsequent events are dependent as well as for the case that the waiting times depend on the preceding events (in this case we speak of an Overshooting Continuous Time Random Maxima, abbr. OCTRM). We get the distribution functions of the limit processes and a formula for the Laplace transform in time of the CTRM and the OCTRM limit. With this formula we have another way to calculate the distribution functions of the limit processes, namely by inversion of the Laplace transform. Moreover, we present governing equations which in our case are time fractional differential equations whose solutions are the distribution functions of our limit processes.