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.     

基于并联FIR滤波器组的Hammerstein预失真器

采用预失真技术对功率放大器的记忆非线性失真进行补偿的关键是预失真器建模的准确性,尤其是模型对功率放大器逆记忆特性的描述能力。针对目前预失真器模型对功率放大器逆记忆效应描述不充分的问题,提出了将查找表(LUT)级联一个具有并联结构的有限长单位冲激响应(FIR)滤波器组作为实现形式的Hammerstein预失真器,以提高传统Hammerstein预失真器的补偿性能,并采用一种两步算法对其参数进行辨识。仿真实验表明,提出的Hammerstein预失真器能更好地补偿带强记忆效应的功率放大器的非线性失真。     

双背压凝汽器抽空气系统的改造及效益分析

分析了某电厂600MW超临界机组双背压凝汽器背压差偏小的原因,为发挥双背压凝汽器的技术优势,对其抽空气系统进行了改造.通过时改造前后抽空气系统不同运行方式的对比试验,证明对双背压凝汽器抽空气系统连接方式的改造,技术上可行,经济效果明显,值得其他同类机组借鉴.     

Panel asymmetric nonlinear unit root test and PPP in Africa

This study revisits purchasing power parity (PPP) theory for 20 African countries using panel asymmetric nonlinear unit root test proposed by Emirmahmutoglu and Omay (2014), through the sequential panel selection method of Chortareas and Kapetanios (2009). While standard panel unit root tests fail to support the PPP, the empirical results from panel asymmetric nonlinear unit root test do support the PPP. However, additional tests reveal that support in all 20 African countries is mostly due to stationarity of the real effective exchange rates of Ghana and Rwanda where the adjustment process towards equilibrium is nonlinear and asymmetric.     

Technological change in energy systems: Learning curves, logistic curves and input-output coefficients

Learning curves have recently been widely adopted in climate-economy models to incorporate endogenous change of energy technologies, replacing the conventional assumption of an autonomous energy efficiency improvement. However, there has been little consideration of the credibility of the learning curve. The current trend that many important energy and climate change policy analyses rely on the learning curve means that it is of great importance to critically examine the basis for learning curves. Here, we analyse the use of learning curves in energy technology, usually implemented as a simple power function. We find that the learning curve cannot separate the effects of price and technological change, cannot reflect continuous and qualitative change of both conventional and emerging energy technologies, cannot help to determine the time paths of technological investment, and misses the central role of R&D activity in driving technological change. We argue that a logistic curve of improving performance modified to include R&D activity as a driving variable can better describe the cost reductions in energy technologies. Furthermore, we demonstrate that the top-down Leontief technology can incorporate the bottom-up technologies that improve along either the learning curve or the logistic curve, through changing input-output coefficients. An application to UK wind power illustrates that the logistic curve fits the observed data better and implies greater potential for cost reduction than the learning curve does.     

发电设备寿命周期费用影响因素的敏感性分析

阐述了发电设备全寿命周期费用（Life Cycle Cost,LCC）的基本理论及计算方法,针对发电设备LCC的影响因素之间存在的客观联系,假定因素之间相互独立,对其中某2个因素的变动幅度进行了一定的修正,使之更贴近实际。以某2×600MW火电机组为例,选取若干影响因素,求得其全寿命周期费用净现值。对目标净现值进行单因素和多因素敏感性分析,以寻找目标值与影响因素之间所存在的内在联系,为设备投资以及后期优化管理提供决策依据。     

基于ANP灰色关联的电力用户重要性评估

鉴于用户的分级管理过程需要对电力用户进行全面和客观的重要性评估,从用户可靠性要求和供电中断危害程度2个方面对用户的重要性进行了考察。在总结用户停电的影响及其关系的基础上,提出了用户重要性的评价指标体系,并利用网络层次分析法（ANP）对各指标进行赋权后,运用灰色关联对用户的重要性作出评估。实例分析验证了该评估方法的实用性和有效性。     

碳信息披露与企业投资效率-基于 2011~2015 年 CDP 中国报告的实证研究

本文以 2011~2015 年参与国际 CDP 项目的中国公司为研究对象,从投资效率视角探析碳信息披露与企业投资效率之间的关系,并就产权性质、管理层权力对二者关系的影响进行检验。结果发现：在其他条件相同的情况下,碳信息披露能够显著提高企业投资效率;同时,相较于非国有企业,国有企业碳信息披露更能提高企业投资效率;管理层权力越大,越会削弱碳信息披露对投资效率的改善作用。进一步研究发现,碳信息披露通过缓解投资不足和抑制过度投资的共同作用来提高企业投资效率,且这种作用在国有企业及管理层权力较低的企业中更为显著。     

强化提升电力企业资金全过程管理的能力

随着市场经济的迅速发展,我国的电力企业市场也在突飞猛进地发展,并对于企业效益的提升起着至关重要的作用。与此同时,也存在着相应问题,需要合理运用良好管理方法,做好企业的资金管理与控制,以此来迎合这新时代背景下竞争激烈的电力市场,有效实现资金内部控制,减少资金使用的随意性。因此,加强资金管控已成为许多企业平稳、顺利转型的关健。基于此,就运用什么方法,如何运用这些方法进行细致讲解,提出相关的方法策略及改善建议。     

Individual best response in the repeated Cournot model

We propose a particular style of punishments to support collusive behavior in an infinitely repeated Cournot oligopoly model for at least the same range of discount factors as Friedman’s trigger strategies. The punishment lasts for a finite number of periods and asymmetry is introduced in such a way that each punisher’s output is the individual best response.