SOME CLASSES OF UPPER EMBEDDABLE GRAPHS

1IntroductionSincetheintroductoryinvestigationofmaximumgenusbyNordhaus,Stewart,andWhite[3],theupperembeddabilityofgraphshasreceivedgreatemphasissofar.AlthoughLiu[16]andNebesky[9]haverespectivelyprovideddifferentnecessaryandsufficientconditionsontheupperembeddabilityofgraphs,weknowlessaboutwhatclassesofgraphsareupperembeddable.Jaeger,PayanandXuong[10]provedthateverygraphobtainedbyconnecting(withanynumberofedges)twovertex-disjointupperembeddablegraphswithevenBettinumberisupperembeddable.Skov…     

一类非线性四阶椭圆型方程的极值原理及其特征值问题

主要应用 Hopf极值原理 ,对一类非线性四阶椭圆型方程Δ2 u +h( x,u,Δu) =0进行研究 ,得到解的泛函的极值原理 .类似的文章结果也有许多 ,其方法均为构造适当的“P-泛函”,但是以前的结果都对方程有较强的要求限制 .本文通过构造新的泛函 ,减弱了要求限制 .同时对方程Δ2 u +λh( x,u,Δu) =0的特征值给出了估计 .     

中国重科一新属一新种(目:粉亚目)

本文记述重科一新属及一新种。     

Aggregation and the estimation of equation systems

Simulations based on two sets of data are used to assess the impact of combining equations on the accuracy of parameter estimates and their asymptotic standard errors.     

函数最值解法技巧探讨

最值问题是生产、生活和科学研究中常遇到的一类问题，本文就如何求解函数最值问题介绍几种方法．     

Large sample inference from single server queues

Problems of large sample estimation and tests for the parameters in a single server queue are discussed. The service time and the interarrivai time densities are assumed to belong to (positive) exponential families. The queueing system is observed over a continuous time interval (0,T] whereT is determined by a suitable stopping rule. The limit distributions of the estimates are obtained in a unified setting, and without imposing the ergodicity condition on the queue length process. Generalized linear models, in particular, log-linear models are considered when several independent queues are observed. The mean service times and the mean interarrival times after appropriate transformations are assumed to satisfy a linear model involving unknown parameters of interest, and known covariates. These models enhance the scope and the usefulness of the standard queueing systems.Partially supported by the U. S. Army Research Office through the Mathematical Sciences Institute of Cornell University.     

欧式向下敲出看涨幂期权的Esscher变换定价

首先根据障碍期权的不同类型,对普通欧式向下敲出看涨幂期权、部分时间开始、部分时间结束、一般部分时间欧式向下敲出看涨幂期权给出定义.通过E sscher变换分别给出定价公式.另外,对两资产欧式向下敲出幂期权也给出了定价公式,为实践者提供了理论上的参考价格.最后,阐述了此方法的优点.     

高温超导磁悬浮系统中横向运动对悬浮力和导向力影响的研究

高温超导磁悬浮列车在运行过程中，导轨磁场的不连续或者机电耦合会引起车身的横向偏移．针对这一实际问题，本文研究了横向运动对竖直悬浮力和水平导向力的影响．实验中系统同时测试横向运动过程中不断变化悬浮力和导向力．研究发现运动过程中的悬浮力衰减与最大横向偏移量和往返运动次数有关；但导向力在第一次往返运动之后的往返运动中迟滞曲线基本不变．该工作可能为高温超导磁悬浮列车系统提供一定科学依据．     

样条指函数

提出了指性表示的概念,证明了函数系1,x,x2,…,xn,x-x1n+,x-x2n+,…,x-xNn+为n次样条指函数集合Sn(x1,x2,…,xN)的指基.给出了应用样条指函数求最大似然估计量的例子.