What can we learn from the fifties?

Economists have increasingly elicited probabilistic expectations from survey respondents. Subjective probabilistic expectations show great promise to improve the estimation of structural models of decision making under uncertainty. However, a robust finding in these surveys is an inappropriate heap of responses at “50%,” suggesting that some of these responses are uninformative. The way these 50s are treated in the subsequent analysis is of major importance. Taking the 50s at face value will bias any aggregate statistics. Conversely, deleting them is not appropriate if some of these answers do convey some information. Furthermore, the attention of researchers is so focused on this heap of 50s that they do not consider the possibility that other answers may be uninformative as well. This paper proposes to take a fresh look at these questions using a new method based on weak assumptions to identify the informativeness of an answer. Applying the method to probabilistic expectations of equity returns in three waves of the Survey of Economic Expectations in 1999–2001, I find that: (i) at least 65% of the 50s convey no information at all; (ii) it is the answer most often provided among the answers identified as uninformative; (iii) but even if the 50s are a major contributor to noise, they represent at best 70% of the identified uninformative answers. These findings have various implications for survey design.     

关于电子自旋不是一种经典模型

本文通过两种方法证明电子自旋不是一种经典模型。     

基于系统工程的系统分类法及应用

首先叙述了一般文献中对系统的分类，然后对钱学森为首的一批知名学者关于系统的人和了介绍。详细地讨论了Ｓｈｅｎｈａｒ和Ｂｏｎｅｎ对系统的二维分类法，并同钱学森的系统分类法进行联系，根据２－Ｄ分类法，提出了系统开发的三维结构，最后对其应用实例进行了说明。     

Best tracking performance for integrator and dead time plant

The optimal tracking performance for integrator and dead time plant in the case where plant uncertainty and control energy constraints axe to be considered jointly is inrestigated.Firstly,an average cost function of the tracking error and the plant input energy over a class of stochastic model errors are defined.Then,we obtain an internal model controller design method that minimizes the average performance and further studies optimal tracking performance for integrator and dead time plant in the simultaneous presence of plant uncertainty and control energy constraint.The results can be used to evaluate optimal tracking performance and control energy in practical designs.     

宜宾市县域经济发展差异动态分析

本文分别运用产出指标和生计指标，对1997～2007年的宜宾市县域经济的绝对差异和相对差异进行了测度。测算结果表明，这11年间宜宾市县域经济的绝对差异和相对差异都呈扩大的趋势。     

师专普通物理实验教学中不确定度的讨论

论述了不确定度在普通物理实验教学中的可行性及计算。     

浅析篮球运动员如何进行专项力量素质训练

力量素质训练在篮球专项中具有重要作用,结合专项力量训练的理论基础,阐述了篮球专项力量素质训练的主要方法。     

数字波面干涉仪的绝对校正问题

数字波面干涉仪是高精度快速评价光学零件的有效工具，绝对校正是数字波面干涉仪研究中的一项重大技术，本文对数字面干涉仪的绝对校正问题作了一些探讨。     

空气比热容比实验不确定度的近似处理

本文对空气比热容比实验不确定度的估计进行讨论，提出一种比较合理、规范又便于教学的近似处理方法。     

论绝对连续函数

本文在测度论的意义下讨论了传统的绝对连续函数这一概念，定义了一种称为依测度绝对连续的概念，并讨论了相应的若干性质，证明了在一维的情形下，依测度绝对连续与通常的绝对连续这两个概念是等价的。给出了当绝对连续函数列收敛时，其收敛的函数是绝对连续函数的条件