碳限额与交易约束下的企业制造/再制造生产决策

目的/意义随着再制造经济效益和环境效益凸显,越来越多的企业进入再制造领域,与原制造商进行竞争或合作。考虑到碳排放约束,企业面临的生产决策更加复杂。设计/方法基于消费者对新产品和再制造产品的异质需求,构建了制造商和再制造商之间的竞争与合作博弈模型,探讨碳税对制造/再制造决策的影响;结合数值仿真,分析了竞争与合作模式下碳税对企业利润及碳排放的影响。结论/发现不同模式下,企业可根据再制造产品碳排放强度选择不同的生产策略;碳税总是会抑制新产品的生产,当再制造产品碳排放强度低于一定数值时,碳税会促进再制造产品的生产;再制造商竞争会挤兑新产品,使制造商利润减少,再制造门槛提高;当碳税不超过一定限度时,合作模式能够实现经济效益和环境效益双赢。     

Semantic Analysis of the Theoretical Foundations of Biology

生物学理论作为科学哲学研究中的一个另类一直受到关注。它与传统科学模式间的差异是造成这种现象的原因之一。解读这种差异的根源,需要对生物学的理论基础以及理论结构给予充分的关注。生物学特有理论结构所表现出的多元语境与语义结构的复杂性,决定了对生物学理论基础的研究应当重视语义分析的方法,尤其是对理论本身进行语义分解并研究其中的语义关联问题,从而解读生物学模式作为一种不同于理化科学的特殊科学解释观的合理性。     

中国产业结构变动与就业水平的实证研究

文章运用时间序列和计量模型研究了中国产业结构与就业水平之间的发展关系.首先运用格兰杰因果检验分析了第一、二、三次产业的产值与其就业之间的因果影响关系,继而从产值与就业两个角度定量分析了第一、二、三次产业各自对总就业水平的贡献,得出结论:第一产业和第三产业是劳动力就业的决定因素,而第二产业不是就业的决定因素;从产值角度来看,第三产业对劳动力就业的贡献最大,从就业角度来看,第一产业的就业对总体就业水平的贡献最高,其次是第三产业,而第二产业的就业对总体就业水平的贡献最小.最后根据研究结论提出相应的建议措施.     

我国生产用能源消费变动的分解分析

摘　　要:能源消费分解是探讨能源消费变动影响因素的一种常用方法。在本文中介绍了目前研究中较为合理的一种分解方法——对数平均D氏指数法,并借助这一方法来对我国“六五”时期以来的生产用能源消费情况进行分解分析,探讨产业结构变动和产业内效率提高对能源消费和总体单位能耗的影响。根据测算结果,笔者认为产业内能源效率的提高是我国能源节约的主要因素;进一步建议政府构建“能源分解指数体系”作为制定能源政策的依据。     

Modelling Variability in the Branching Structure of Strawberry Inflorescences

The branching structure of inflorescences of the cultivated strawberry ( Fragaria × ananassa Duch.) is very variable. This paper demonstrates that some aspects of this variability are well described by a simple stochastic model of branching that has two adjustable parameters. The model is shown to provide a good fit to data from a set of almost 700 inflorescences of the cultivar Elsanta, collected over two successive years. For one parameter the maximum likelihood estimator is a moment estimator which is fully efficient even if the detailed branching structure of the inflorescences is not recorded. This parameter provides a convenient summary of branching vigour. The maximum likelihood estimator of the second parameter must be determined iteratively and can be quite inefficient unless the full branching structure is recorded. The model demonstrates that branching structure is affected by the order in which inflorescences emerge on the plant.     

小议带引导词there的句子

本文着重探讨“ Ｔｈｅｒｅ ＋ ｂｅ ＋ 名词词组（ ＋ 状语）”结构的某些特殊用法,尤其是该结构在非正式文体中及在方位句、存在句和状态句中的特殊用法     

试论时间价值观

时间是一种重要的资源。时间价值观是个体以自身的需要为尺度对时间重要性的稳定态度和观念。时间价值观含有时间资源观、时间效率观、时机观、时间顺序观等方面的意义。时间价值观的结构可以有不同的划分。时间价值观受社会文化传统、个体的年龄因素、个体性格、社会环境等因素的影响。心理学对时间价值观的研究在理论上和应用中都有着重要的意义     

Causality and interdependence analysis in linear econometric models with an application to fertility

This paper is an applied analysis of the causal structure of linear multi-equational econometric models. Its aim is to identify the kind of relationships linking the endogenous variables of the model, distinguishing between causal links and feedback loops. The investigation is first carried out within a deterministic framework and then moves on to show how the results may change inside a more realistic stochastic context. The causal analysis is then specifically applied to a linear simultaneous equation model explaining fertility rates. The analysis is carried out by means of a specific RATS programming code designed to show the specific nature of the relationships within the model.     

The rank distribution of the maximin in a random matrix

Let S be a set of tm distinct real numbers and R a random t × m matrix of these tm numbers with rows {r_i} and columns (c_i}. Define b = Max Min x. l≤i≤t x?r_i. Let c be the event Max Min x = Min Max x. l≤i≤t x?r_i l≤i≤m x?c_i. This paper derives the probability distribution of the rank of b in S, as well as the same distribution conditional on c.     

Robust Correlation Structure for Multivariate Failure Time Data

When incomplete repeated failure times are collected from a large number of independent individuals, interest is focused primarily on the consistent and efficient estimation of the effects of the associated covariates on the failure times. Since repeated failure times are likely to be correlated, it is important to exploit the correlation structure of the failure data in order to obtain such consistent and efficient estimates. However, it may be difficult to specify an appropriate correlation structure for a real life data set. We propose a robust correlation structure that can be used irrespective of the true correlation structure. This structure is used in constructing an estimating equation for the hazard ratio parameter, under the assumption that the number of repeated failure times for an individual is random. The consistency and efficiency of the estimates is examined through a simulation study, where we consider failure times that marginally follow an exponential distribution and a Poisson distribution is assumed for the random number of repeated failure times. We conclude by using the proposed method to analyze a bladder cancer dataset.