Information theoretic multivariate graduation

Abstract

This paper presents a new multivariate graduation method based upon a constrained information theoretic methodology. The statistical formulation of the graduation problem is shown to result in a convex mathematical programming problem thus allowing the actuary to include constraints such as monotonicity along the rows, monotonicity down the column, monotonicity along the upward diagonal, as well as convexity, and any of a variety of other relationships desired for the graduated series. An illustrative application is made to the graduation of select and ultimate mortality tables.     

汇率影响进出口国别结构的机理分析及弹性测度

通过机理分析,建立了汇率变化影响进出口国别结构的数理模型,计算出当汇率贬值或升值时,我国对各国出口、进口比重上升或下降,出口、进口需求价格弹性必须满足的条件。同时运用回归和弹性定义法,使用估算和精算相结合,测算了我国对五大贸易伙伴国进出口需求弹性,并将机理分析与弹性测度进行对比。     

证据推理在数学模型信度检验中的应用浅析

数学模型在解决实际问题中具有重要地位和作用。针对同一问题 ,不同的数学模型往往有不同的信度 ,有时甚至相差甚远。如何检验数学模型的信度 ,是我们经常遇到的问题。利用 Dempster-Shafer合成法则 ,给出了数学模型与经验知识的合成公式 ,它可以作为一种检验数学模型信度的可行而简便的方法。     

Joint production under uncertainty and multifunctionality of agriculture: policy considerations and applied analysis

The impact of various policy instruments on the production ofenvironmental goods that are complementary to or competing withagricultural commodities is analysed in the light of the uncertaintyin output prices and farmers' risk aversion. Some theoreticalassessments are first summarised and then tested on a case studyconcerning beef and grassland biodiversity production in Montsdu Cantal, France. The results of simulations carried out bymathematical programming farm-level models show that joint commodityand non-commodity production is nearly independent of the degreeof farmers' risk aversion, and that commodity-linked policyinstruments are not suitable for the production of environmentalgoods even under uncertainty.     

中小型变压器负载突降的数学模型及数值计算

本文建立了变压器功率负载突然降低时电压平衡方程式。以电流为状态变量,时间为自变量,用龙格——库塔法求出数值解。用 FORTRAN 语言编写程序。给出了程序框图和仿真结果曲线,供模拟参考。     

两支承车床主轴的优化设计

本文主要讨论了两支承车床主轴的优化问题,较详细地叙述了数学模型的建立过程,给出了用复合形法进行优化的框图,并对优化结果进行了分析。     

关于数学模型在培养技能型人才中的应用研究

数学模型是根据数学知识而构建的一种实践模型,相比传统的数学学习,模型传授方式会有利于培养学生的创新能力,增强学生的数学应用能力,提高学生的实践能力的培养。本文从对数学模型的理论原理的分析,阐述数学模型对培养技能型人才的积极意义,最后提出数学模型在数学教学中的应用措施。     

双作用变量叶片泵的数字化研究

介绍了一种以歩进电机作为机电转换装置,以单片机作为控制器的数字式双作用变量叶片泵。在结构和工作原理分析的基础上,建立了变量机构的数学模型,分析了变量过程中输出流量与调节参数的关系。分析结果表明,对双作用变量叶片泵的数字化改进是可行的。     

基于职业核心能力的高职英语“项目学习”的教学设计和实践

将职业核心能力理论与项目学习模式相结合,为高职英语教学改革提供了新的思路。有助于增强高职学生学习的兴趣、信心和成效。推动高职英语教师的教材观、师生观、教学观的变革,为高职英语公共英语教学提供有针对性的教学模式和策略,形成具有职业特色的英语"项目学习"教学模式,对高职院校有实际应用、推广价值。     

Farm-based modelling of the EU sugar reform: impact on Belgian sugar beet suppliers

A mathematical programming model, calibrated on individual farmdata, is used to analyse the reform of the common market organisation(CMO) in the sugar sector of the European Union. The model includesa precautionary farm supply function for out-of-quota sugarbeet that is estimated as part of a simultaneous system of first-orderconditions. Simulation results from a sample of Belgian sugarbeet farms show that the sugar CMO reform induces differentsupply and income effects across farms depending on their shareof out-of-quota sugar beet relative to their total beet supplyand their quota rent. A further cut in the minimum price ofsugar beet initiates structural change in the farm sector.