旅游需求函数的研究

由于旅游区价格具有一定的刚性和稳定性，采用直接观察法不易得出旅游需求函数。文章通过对旅行成本法的研究，首次提出试用旅游复合成本的变化来替代旅游区价格的变化，综合考虑收入、时间的机会成本等因素，使用出游率和旅游复合成本2个指标，建立旅游需求函数，揭示旅游需求规律，探索出一种简易可行计算旅游需求函数的方法。     

Design considerations for neyman-pearson and wald hypothesis testing

Summary The Neyman-Pearson Lemma describes a test for two simple hypotheses that, for a given sample size, is most powerful for its level. It is usually implemented by choosing the smallest sample size that achieves a prespecified power for a fixed level. The Lemma does not describe how to select either the level or the power of the test. In the usual Wald decision-theoretic structure there exists a sampling cost function, an initial prior over the hypothesis space and various payoffs to right/wrong hypothesis selections. The optimal Wald test is a Bayes decision rule that maximizes the expected payoff net of sampling costs. This paper shows that the Wald-optimal test and the Neyman-Pearson test can be the same and how the Neyman-Pearson test, with fixed level and power, can be viewed as a Wald test subject to restrictions on the payoff vector, cost function and prior distribution.     

An approximation to the limit distribution of the epps-pulley test statistic for normality

Summary The approach of Epps and Pulley (1983) based on the empirical characteristic function is one of the most powerful tools for detecting any departures from normality. We obtain the first four moments of the limiting null distribution of the Epps-Pulley Statistic. Johnson- and Pearson curve fitting yields excellent approximations to simulated quantiles, and by modifying the test statistic the procedure may be carried out easily without the use of extensive tables for all sample sizes. Research done while the author was on leave at the University of Gie?en.     

国际购买力平价和简化净出口函数:中国实证

文章从国际交换价值的角度研究了一价定律的内涵,提出了国际购买力平价理论,并且证明了国际购买力平价是严格意义上的均衡汇率。2009年人民币贸易品购买力平价为6.70元人民币/美元,而国际购买力为5.49元人民币/美元,后者可作为确定人民币汇率处于均衡水平的参考。文章还简化了净出口函数,得出如下主要结论:(1)近年我国的贸易顺差大幅增长,主要是因为价格贸易条件恶化,其次是因为J曲线效应;(2)当前的首要任务是改善我国的价格贸易条件以提高国际购买力平价,而不是调整人民币汇率。     

城镇居民收入分布函数的研究

有关我国居民收入分布函数的研究尚属空白,本文利用2005～2010年安徽省城镇住户调查数据来探讨我国城镇居民的收入分布函数,统计计算表明部分分布函数估计的拟合效果优于非参估计,而参数估计中,多参数分布函数的拟合效果优于两参数分布函数。本文还探讨了部分分布函数的特点及其在收入不平等领域中的运用,我们发现居民平均收入与中位数的比值可以直接用来衡量居民的收入不平等。另外,我们还讨论了在某些分布条件下,贫困发生率与基尼系数之间的数量关系。     

五次函数及其性质的研究

本文通过对三次函数和四次函数及其曲线性质的研究,利用各次幂的系数来确定五次函数的极值点以及拐点的存的条件,并给出了求拐点和极值的计算公式。     

Excess capacity,production technology and technical inefficiency in hospitality sector

This article examines the effects of excess capacity on the production cost and technical inefficiency of hotels and restaurants in Norway. The dataset includes a daily unbalanced panel of 94 hotels and restaurants from 2003 to 2014. To accommodate inefficiency, we use an input distance function (IDF). Inefficiency in the IDF means that if inputs are overused by k% then production cost is also increased by k%. We also allow inefficiency to differ across locations and regions by using them as determinants. The results indicate that excess capacity considerably affects the cost and increases inefficiency. The marginal effect on cost increases with excess capacity, but the effect on inefficiency sets in when it exceeds 50 percent. Furthermore, we find less overuse of inputs by firms in small metro towns and the Northern region causing them to be more efficient [except for the Southern and Western regions] than their counterparts.     

热分析仪SDT-2960的特点及新应用

较详细地介绍了美国ＴＡ公司的ＳＤＴ－２９６０热分析仪的结构、原理、性能,并对其主要应用进行了举例和探讨。     

矿泉水瓶再生设计研究

由于500ml左右矿泉水瓶瓶口具有统一的螺纹规格,其次,瓶体的容量也具有接近统一的标准,这就为矿泉水瓶再生设计的开发提供了必要的前提。市场上关于矿泉水瓶的再生设计多利用矿泉水瓶作为盛水的容器,而没有继续探讨其盛放小型垃圾(瓜子壳,纸屑,铅笔屑等)的功能。本文以绿色设计中延长产品生命周期的理念为原则,以联想法、模仿法及组合法等产品设计方法为指导,推出一款全新的使用矿泉水瓶衍生功能的产品,并着重介绍在本设计进行的过程中得出的新的设计方法:系统化条件下的功能衍生法。通过这款设计来说明现有产品衍生出新的功能的可行性,并总结一定的设计经验与设计方法,为以后进行相关设计奠定理论和方法基础。     

基于无交叉遗传算法的物流车辆路径问题研究

设计并实现了一种求解基本车辆路径问题的无交叉遗传算法,阐述了无交叉遗传算法求解物流车辆路径问题的关键技术,包括编码方案、初始种群生成方案、适应度函数、种群选择方案和变异操作等;并对比了使用目标函数倒数法和目标函数做差法构造适应度函数时的求解效果。实验结果表明,给出的无交叉遗传算法在求解车辆路径问题上具有良好的性能。