未确知数减法运算的推广

本文是文献[1]定义的未确知数减法运算的推广,且给出了一个新的定义方式.     

Additive Structural Decomposition Analysis and Index Number Theory: An Empirical Application of the Montgomery Decomposition

In recent years, a large number of empirical articles on structural decomposition analysis, which aims at disentangling an aggregate change in a variable into its r factors, has been published in this journal. Commonly used methods are the average of the two polar decompositions and the average of all r! elementary decompositions (Dietzenbacher and Los, 1998 Dietzenbacher, E. and Los, B. 1998. Structural decomposition techniques: sense and sensitivity. Economic Systems Research, 10: 307–323. [Taylor & Francis Online] [Google Scholar], D&L). We propose to use instead the ‘ideal’ Montgomery decomposition, which means that it satisfies the requirement of factor reversal imposed in index number theory. We prefer it to the methods previously mentioned. The average of the two polar decompositions is not ‘ideal’, so that the outcome depends on the ordering of the factors. The average of all elementary decompositions is ‘ideal’, but requires the computation of an ever increasing number of decompositions when the number of factors increases. Application to the example of D&L (four factors) shows that the three methods yield results that are close to each other.     

The average number of events per time unit and its estimation

Let ζ _t be the number of events which will be observed in the time interval [0;t] and define as the average number of events per time unit if this limit exists. In the case of i.i.d. waiting-times between the events,E[ζ _t ] is the renewal function and it follows from well-known results of renewal theory thatA exists and is equal to 1/τ, if τ>0 is the expectation of the waiting-times. This holds true also when τ = ∞.A may be estimate by ζ _t /t or where is the mean of the firstn waiting-timesX ₁,X ₂, ...,X _n . Both estimators converage with probability 1 to 1/τ if theX _i are i.i.d.; but the expectation of may be infinite for alln and also if it is finite, is in general a positively biased estimator ofA. For a stationary renewal process, ζ _t /t is unbiased for eacht; if theX _i are i.i.d. with densityf(x), then ζ _t /t has this property only iff(x) is of the exponential type and only for this type the numbers of events in consecutive time intervals [0,t], [t, 2t], ... are i.i.d. random variables for arbitraryt > 0.     

基于TOPSISI的空管运行单位安全能力分类评估研究

从空管一线运行单位的安全出发,考虑到航班量逐年递增以及各空管运行单位年飞行保障量存在较大地区性差异。为使各空管运行单位现有安全保障能力与其飞行保障量更好的匹配,将塔台、区域保障架次和跑道数量作为重要的属性来进行空管安全能力评估单位分类。运用已构建的评估指标体系,采用标准离差法-TOPSIS排序法,通过输出结果验证单位分类评估的合理性。     

机关事业单位养老保险制度改革的收入再分配效应

论文采用精算方法,选择终身净转移额和内部收益率两大指标,从全国和地区两个层面,定量分析了机关事业单位养老保险制度改革的代内再分配效应和代际再分配效应。研究结果表明:养老保险制度改革对城镇职工、其他制度模式下的参保群体、不同地区、代与代之间的收入再分配效应,主要取决于工资增长率和利率的动态组合,新制度既可以发挥正向的代内再分配效应和代际再分配效应,也可能会引起代内不公平和代际不公平,而且再分配效应会随缴费年限增加而增强。     

基于普通摄像头的人数检测技术的探讨

本文利用普通摄像头在人脸检测的基础上,对视频或图像中出现的人数进行统计,为了提高统计的准确性,本文引入背景差的方法,从而大大改善了人数统计的精度,试验证明了方法的有效性。     

T型微通道内两相流动数值模拟和流场分析

借助相场方法数值模拟T型微通道内两相流动,通过改变毛细数大小,得到三种形成机理下的离散相。随着毛细数增大,离散相形成过程对微通道内压强和速度的影响减弱。     

数形结合思想在高职数学教学中的运用

文章从对概念、定理的理解以及解题等方面归纳总结了数形结合思想在高职数学教学中的应用。     

基于指数趋势预测模型的韶山红色旅游景区游客数量预测研究

游客人数是衡量景区发展的重要指标之一，游客数量变化总体上受控于资源禀赋、区位交通、景区环境、经济发展等众多因素。依据韶山景区近9年的游客接待量，选用指数趋势预测模型对韶山红色旅游景区未来五年游客数量进行预测，得出区间预测结果。预测结果表明韶山旅游景区正处于稳定成熟的发展阶段。为保持良好的发展势头，应加强市场营销，开发景区内部动态旅游产品，提高旅游从业者水平，完善景区基础设施建设，实现韶山旅游业又快又好的发展。     

一类多面体链环模型的性质分析

多面体链环是由多个相互镶嵌而成的具有多面体形状的一种拓扑几何结构。构筑了一种新型的多面体链环L(P),给出了该链环的分支数c(L(P))的一个计算公式:c(L(P))=e(P)+v(P)。其中:v(P)和e(P)分别表示多面体P的顶点数和边数。此外,当f(P)-v(P)≠3e(P)时,得到的这类多面体链环是具有手性的,其中f(P)表示多面体P的面数。