Economic interpretations of DEA

Research on productive efficiency at the firm level has developed as an important and active strand of research the last decades, both within operations research, management science and economics. Two apparently different definitions of efficiency are examined, but it is shown that when both estimation methods are based on solving linear programming problems the definitions of efficiency are identical. The purpose of the paper is to give the basic ideas of efficiency analyses using DEA as a tool for researchers not so familiar with efficiency analysis and DEA. The concept of shadow prices is given special attention.     

用AD9852与FPGA结合实现中频线性调相

本文介绍了直接数字频率合成（DDS）芯片AD9852与可编程门阵列（FPGA）相结合采用数字方法实现中频线性相位调制（PM）及试验结果。     

液晶显示器的应用

本文以２种具有代表性的液晶显示器为例，介绍了液晶显示器的硬件设计方法和软件编程方法。同时介绍了一种液晶显示器的汉字显示方法。     

Enders-Granger方法在协整检验中的应用研究

本文将协整检验由传统的线性协整检验扩展到线性协整检验和阈值协整检验,并在Enders和Granger(1998)方法的基础上提出了一个新的检验协整是否存在的Sup-F和Sup-F*统计量。通过MC仿真研究发现:在线性协整下,ADF方法比Sup-F法具有更高的检验势,但在"持久性"较强时,Sup-F检验比ADF检验法具有更高的检验势;Sup-F统计量在Three-Regime的阈值协整检验中比ADF法有更高的检验势;Sup-F*在检验协整(包括线性协整和阈值协整)时都具有较低的检验势;随着在不同Regime中自回归系数差距的增大(非对称程度增大),sup-F统计量的检验势提高很快,且比ADF法的检验势高。     

Linear Programming Models for the Measurement of Environmental Performance of Firms—Concepts and Empirical Results

I use linear programming models to define standardised, aggregate environmental performance indicators for firms. The best practice frontier obtained corresponds to decision making units showing the best environmental behaviour. Results are obtained with data from U.S. fossil fuel-fired electric utilities, starting from four alternative models, among which are three linear programming models that differ in the way they account for undesirable outputs (pollutants) and resources used as inputs. The results indicate important discrepancies in the rankings obtained by the four models. Rather than contradictory, these results are interpreted as giving different, complementary kinds of information, that should all be taken into account by public decision-makers.     

总收益最大的交易策略求解算法

本文应用动态规划的原理,讨论了多期投资决策中基于总收益率最大的交易策略的设计和实现问题。通过比较随机交易方法、局部最优方法和全局最优方法下的投资表现,在交易费用存在的情况下,基于动态规划的算法给出问题的全局最优解,该方法的优越性随着交易费用的增长而加强。     

公司债务期限结构影响因素的实证分析

本文以上市公司板面数据及横截面数据为基础,利用混合时间序列回归、横截面回归和固定效果回归等方法,对影响我国上市公司债务期限结构的因素进行了实证检验。结果发现,除契约成本假说中成长机会外,绝大部分因素的检验结果与预期一致,进而验证了其适用性;经验证据不支持信息不对称假说;对税负假说相关因素的检验结果表现出不确定性;期限匹配假说得到了支持。研究还证明,具有较少自由现金流量、杠杆水平较高、规模大、受到管制和资产期限长的公司具有更多的长期债务。     

Asymptotic behaviour of regression pre-test estimators with minimal Bayes risk

Pre-test estimators (PTE) are considered which are optimal under a Bayes risk among PTE with general measurable sets as “regions of significance” for the test statistic t associated with the estimate of a given regression coefficient. Asymptotic and some finite sample results are stated and numerical experiments are commented on.     

Lp空间上线性回归方程回归系数的估计

本文讨论了多元线性回归方程参数的L^p估计问题。首先采取消除方程中参数“。的技术，化参数估计为对回归系数的估计，然后进一步将问题转化为一个单目标数学规划模型，利用能自动搜索最优解的电脑软件，十分方便地求出规划模型的最优解。特别对一元回归方程，在消除参数a0后，还可以直接利用普通一元函数求极值的方法，求出回归系数的估计。     

中国经济增长与能源消费空间面板分析

近年来面板数据广泛应用于各类统计分析,但变量的空间相关并没有引起足够的重视。本文引入空间面板回归模型研究中国各省市区经济增长和能源消费的关系。利用matlab软件及其spatial econometric模块建立和比较传统面板回归模型与空间面板回归模型,结果表明空间面板回归模型较传统面板回归模型优越,本文的研究为空间面板数据分析提供了一个应用实例。