Rn中△u+K(|x|)up=0的正奇解

本文利用不同的函数变换及Banach空间压缩影象原理,证明了Rm中半线性椭园方程△u+K(|x|)up=0无限多个奇解的存在性,并且具有渐进性广rn-2u(r)→c＞0(r→∞).     

A note on the prize collecting traveling salesman problem

We study the version of the prize collecting traveling salesman problem, where the objective is to find a tour that visits a subset of vertices such that the length of the tour plus the sum of penalties associated with vertices not in the tour is as small as possible. We present an approximation algorithm with constant bound. The algorithm is based on Christofides' algorithm for the traveling salesman problem as well as a method to round fractional solutions of a linear programming relaxation to integers, feasible for the original problem.Research supported in part by ONR contract N00014-90-J-1649 and NSF contract DDM-8922712.     

ON THE UNIFORM DISSIPATIVITY OF SOME FIFTH-ORDER NON-LINEAR DIFFERENTIAL EQUATIONS

This paper studies the problem of uniformly dissipative solutions of somefifth order non-linear differential equations by the use of frequency domaintechnique. We use the generalized theorem of Yacubovich on dissipativity toobtain some new sufficient conditions of the existence of solutions that aredissipative for (1.1) and (1.2).     

消费者心理违约对品牌权益的影响机制研究

本文旨在把组织行为学中的心理契约理论应用于市场营销情景下的品牌关系。本文通过把心理违约分成两个阶段,即心理违约(Psychological Contrac(?) Breach)和心理违背(Psychological Contract Violation)来研究消费者心理违约对品牌权益的影响。结果显示,心理违背会负面地影响品牌形象和品牌忠诚。但在心理违约和心理违背之间还存在着其它影响因素,有待进一步的研究。     

SOLVXBILITY OF FORWARD－BACKWARD SDES AND THE NODAL SET OF HAMILTON－JACOBI－BELLMAN EQUATIONS

ＳＯＬＶＸＢＩＬＩＴＹＯＦＦＯＲＷＡＲＤ－ＢＡＣＫＷＡＲＤＳＤＥＳＡＮＤＴＨＥＮＯＤＡＬＳＥＴＯＦＨＡＭＩＬＴＯＮ－ＪＡＣＯＢＩ－ＢＥＬＬＭＡＮＥＱＵＡＴＩＯＮＳ￥ＭＡＪＩＮ；ＹＯＮＧＪＩＯＮＧＭＩＮＡｂｓｔｒａｃｔ：Ｔｈｅｓｏｌｖａｂｉｌｉｔｙｏｆ...     

权益连结生存人寿保险合同的局部风险最小对冲策略

权益连结生存人寿保险合同是保险金依赖于某类特定股票的价格的保险合同 .本文主要利用Schweizer[3]引入的不完全市场的局部风险最小理论确定单位关联人寿保险合同的局部风险最小对冲策略 .     

Contract design for technology sharing between two farmers

Technology sharing among farmers has become common but controversial in recent years. To address it, we consider two farmers engaged in Cournot competition to investigate motivations of technology sharing and provide suggestions on contract design. One farmer (a licensor) has developed some technology and decides whether to share technology with the other farmer (a licensee). The licensee chooses whether to buy technology under a fixed-rate contract or a royalty-fee contract. We propose a technology sharing ratio between two farmers to characterize the degree of technology sharing. We find a win–win outcome for both farmers when the technology sharing ratio is higher than a threshold under the fixed-fee contract. While under the royalty-fee contract, the licensor only shares technology with an additional constraint that they have similar production costs. When the licensor can design contracts, he prefers the royalty-fee contract to the fixed-fee contract. We further interpret why the licensor may not benefit more under the two-part tariff contract than the fixed-fee or the royalty-fee contract. Moreover, we find that in supply chain settings, a win–win outcome for both farmers exists if and only if the technology sharing ratio is smaller than a threshold under the fixed-fee contract while technology sharing will not be realized under the royalty-fee contract. Finally, we show that the strategy of whether to share technology is robust to yield uncertainty, and both the licensor and licensee may benefit more from technology sharing because of yield uncertainty.

     

Bounded and almost periodic solutions of convex Lagrangian systems

We study some properties of bounded and almost periodic solutions of convex Lagrangian systems in the presence of almost periodic forcing

     

ON THE SELF-SIMILAR SOLUTIONS OF THE MAGNETO-HYDRO-DYNAMIC EQUATIONS

In this paper, we show that, for the three dimensional incompressible magnetohydro-dynamic equations, there exists only trivial backward self-similar solution in L^p（R^3） for p ≥ 3, under some smallness assumption on either the kinetic energy of the self-similar solution related to the velocity field, or the magnetic field. Second, we construct a class of global unique forward self-similar solutions to the three-dimensional MHD equations with small initial data in some sense, being homogeneous of degree -1 and belonging to some Besov space, or the Lorentz space or pseudo-measure space, as motivated by the work in [5].     

On the determination of the number of periodic (or closed) solutions of a scalar differential equation with convexity

It is well known that a scalar differential equation , where f(t,x) is continuous, T-periodic in t and weakly convex or concave in x has no, one or two T-periodic solutions or a connected band of T-periodic solutions. The last possibility can be excluded if f(t,x) is strictly convex or concave for some t in the period interval. In this paper we investigate how the actual number of T-periodic solutions for a given equation of this type in principle can be determined, if f(t,x) is also assumed to have a continuous derivative . It turns out that there are three cases. In each of these cases we indicate the monotonicity properties and the domain of values for the function P(ξ)=S(ξ)−ξ, where S(ξ) is the Poincaré successor function. From these informations the actual number of periodic solutions can be determined, since a zero of P(ξ) represents a periodic solution.     

Framing contingencies in contracts

This paper develops a contracting model in which the principal frames the contract when the agent is unaware of some contingencies, yet is aware that she may be unaware. We call the contract vague if the agent is still unaware of some contingencies after understanding the contract. We show that the optimal contract is vague if and only if the principal exploits the agent. Applying the model to an insurance problem, we show the insuree is free from exploitation if she slightly underestimates the unforeseen calamities. In a contracting problem, whenever the contractor is unaware of the force majeure event, she is exploited by the employer.     

MODELING COMMON PROPERTY OWNERSHIP AS A DYNAMIC CONTRACT

Common property ownership is modeled as a joint wealth maximizing egalitarian share contract. Two-stage differential games are developed for various types of common property in order to examine the incentives inherent in common property regimes. Cases in which group members contract over just membership size and cases in which members contract over both group size and resource investment are considered. Envelope methods in optimal control theory are used to generate some comparative statics predictions about the value of the contracts which define property rights to a capital stock.     

On the solution and complexity of a generalized linear complementarity problem

We introduce some sufficient conditions under which a generalized linear complementarity problem (GLCP) can be solved as a pure linear complementarity problem. We also establish that the GLCP is in general a NP-Hard problem.Support of this work has been provided by the Instituto Nacional de Investigação Cientifica de Portugal (INIC) under contract 89/EXA/5.     

Behavior of positive radial solutions for quasilinear elliptic equations

We establish a necessary and sufficient condition so that positive radial solutions to 0, \end{equation*}"> having an isolated singularity at , behave like a corresponding fundamental solution. Here, and are continuous functions satisfying some mild growth restrictions.

     

基于优惠合同的在线租赁策略设计

近年来租赁行业竞争日益激烈,租赁企业为了吸引客户有时会开展一些优惠活动。针对这一现状,本文讨论了存在优惠合同时承租方的在线租赁决策问题,其中假设该优惠合同 给予承租方一次以比较优惠的价格连续租赁设备多期的机会。首先,分析了存在优惠合同时的最优离线策略。其次,利用在线算法和竞争比理论分别设计了承租方放弃优惠合同和签订优惠 合同两种情形下的最优在线策略及最优竞争比。最后,通过汽车租赁优惠的数值算例说明选择签订优惠合同是更好的策略,进一步给出了签订优惠合同和购买设备的最佳时间。     

关于运输问题最优解的进一步讨论

首先给出了运输问题最优解的相关概念,将最优解扩展到广义范畴,提出狭义多重最优解和广义多重最优解的概念及其区别.然后给出了惟一最优解、多重最优解、广义有限多重最优解、广义无限多重最优解的判定定理及其证明过程.最后推导出了狭义有限多重最优解个数下限和广义有限多重最优解个数上限的计算公式,并举例验证了结论的正确性.     

(G'/G²)-expansion Solutions to MBBM and OBBM Equations

In this paper,with the aid of symbolic computation, themodified Benjamin- Bona-Mahony and Ostrovsky-Benjamin-Bona-Mahony equations are investigated by extended (G'/G2)-expansion method. As a consequence, some trigonometric, hyperbolic and rational function solutions with multiple arbitrary parameters for the two equations are revealed, which helps to illustrate the effectiveness of this method.