A Continuous Representation of the Family of Stable Law Distributions

Conventional parametric representations of stable law distributions do not allow all members of the family to be obtained as continuous limits of the parameters. Model building (or simulation) using such representations will be numerically unstable near such limits in consequence. Existing tables are not satisfactory near such limits as interpolation cannot be carried out. We show that these difficulties are overcome by using a new shifted Cartesian representation which characterizes the entire stable law family in a completely continuous way. Standardization is still possible with this representation so that tabulation, using just two bounded parameters, can be carried out. Its use is illustrated in a non-regular threshold estimation problem involving stable distributions which are discontinuous limits in conventional representations.     

Profile upper Confidence Limits from Discrete Data

When the data are discrete, standard approximate confidence limits often have coverage well below nominal for some parameter values. While ad hoc adjustments may largely solve this problem for particular cases, Kabaila & Lloyd (1997) gave a more systematic method of adjustment which leads to tight upper limits, which have coverage which is never below nominal and are as small as possible within a particular class. However, their computation for all but the simplest models is infeasible. This paper suggests modifying tight upper limits by an initial replacement of the unknown nuisance parameter vector by its profile maximum likelihood estimator. While the resulting limits no longer possess the optimal properties of tight limits exactly, the paper presents both numerical and theoretical evidence that the resulting coverage function is close to optimal. Moreover these profile upper limits are much (possibly many orders of magnitude) easier to compute than tight upper limits.     

应用AutoLISP对AutoCAD进行二次开发时的研究

AutoLISP语言是AutoCAD用户广泛使用的二次开发工具，本文结合笔者的开发体会，提出了在AutoLISP编程中需要注意的几个问题。     

正交优化法的软件设计及其应用

本文用BASIC语言编制了正交优化法软件，并通过实例对其应用进行探讨，研究结果表明：用正交优化法处理化学、环保等方面的非线性模型的参数估值和非线性回归问题是非常有效的。     

完全检查下预防维修模型建立及案例分析

为了解决维修间隔期确定的难题,建立了维修间隔期和总停机时间之间关系的目标函数,以及时间延迟维修模型.根据故障记录数据和预防维修活动的检查数据,采用最大似然法估计有关缺陷发生率和时间延迟分布等参数.在所建立目标函数和估计参数的基础上,计算出最优的维修间隔期.     

受迫Duffing振子浑沌运动的控制

本文研究了受迫Duffing振子产生浑沌运动时的控制问题，通过周期激振力、参数激扰、自适应控制和连续反馈控制来抑制和控制其中的浑沌运动，使系统从浑沌运动状态转变到规则运动状态．数值分析表明，在适当的控制信号作用下，受迫Duffing振子中的浑沌运动得到了很好的控制．     

高保密性的时变参数混沌同步通信方法

提出了一种时变参数混沌同步保密通信方法,极大地提高了混沌同步的通信保密性,使目前的各种破译手段均无法破译该方法;并基于Chua电路进行了仿真。采用该方法进行混沌同步通信,击败了目前各种破译手段的攻击,证实了其高保密性。     

Estimation of the Force of Infection from Current Status Data Using Generalized Linear Mixed Models

Based on sero-prevalence data of rubella, mumps in the UK and varicella in Belgium, we show how the force of infection, the age-specific rate at which susceptible individuals contract infection, can be estimated using generalized linear mixed models (McCulloch & Searle, 2001). Modelling the dependency of the force of infection on age by penalized splines, which involve fixed and random effects, allows us to use generalized linear mixed models techniques to estimate both the cumulative probability of being infected before a given age and the force of infection. Moreover, these models permit an automatic selection of the smoothing parameter. The smoothness of the estimated force of infection can be influenced by the number of knots and the degree of the penalized spline used. To determine these, a different number of knots and different degrees are used and the results are compared to establish this sensitivity. Simulations with a different number of knots and polynomial spline bases of different degrees suggest - for estimating the force of infection from serological data - the use of a quadratic penalized spline based on about 10 knots.     

进口对辽宁省经济增长贡献度的实证分析——基于时变参数卡尔曼滤波的估计

为了探寻辽宁对外经济发展的合理模式，从进口与经济增长间的关系入手，选用1985～2007年辽宁省的进口和地区生产总值数据，利用时变参数的分析方法对二者进行相关性分析，得出了进口对辽宁省的经济增长存在促进作用，而且这种作用随时递增的结论。因此，辽宁省应充分发挥进口对经济增长的积极作用，以快速实现辽宁老工业基地的振兴。     

低高度曲线箱梁桥参数分析

本文分别采用空间板壳及梁格模型对曲线箱梁桥的曲率半径、支承方式、腹板厚度进行了参数分析，明确了其对箱梁主要部位静活载内力、结构变位及支承反力的影响