Quantifying uncertainty in the biospheric carbon flux for England and Wales

Summary.  A crucial issue in the current global warming debate is the effect of vegetation and soils on carbon dioxide (CO₂) concentrations in the atmosphere. Vegetation can extract CO₂ through photosynthesis, but respiration, decay of soil organic matter and disturbance effects such as fire return it to the atmosphere. The balance of these processes is the net carbon flux. To estimate the biospheric carbon flux for England and Wales, we address the statistical problem of inference for the sum of multiple outputs from a complex deterministic computer code whose input parameters are uncertain. The code is a process model which simulates the carbon dynamics of vegetation and soils, including the amount of carbon that is stored as a result of photosynthesis and the amount that is returned to the atmosphere through respiration. The aggregation of outputs corresponding to multiple sites and types of vegetation in a region gives an estimate of the total carbon flux for that region over a period of time. Expert prior opinions are elicited for marginal uncertainty about the relevant input parameters and for correlations of inputs between sites. A Gaussian process model is used to build emulators of the multiple code outputs and Bayesian uncertainty analysis is then used to propagate uncertainty in the input parameters through to uncertainty on the aggregated output. Numerical results are presented for England and Wales in the year 2000. It is estimated that vegetation and soils in England and Wales constituted a net sink of 7.55 Mt C (1 Mt C = 10¹² g of carbon) in 2000, with standard deviation 0.56 Mt C resulting from the sources of uncertainty that are considered.     

外商直接投资对我国三大都市圈技术外溢效应的比较研究

本文对外商直接投资在我国三大都市圈的技术外溢效应进行了比较研究,结果表明,外商直接投资在整体上对三大都市圈的技术外溢效应显著,但不同地区之间存在着明显的差别。三大都市圈应在不断加强对外商直接投资技术外溢的消化吸收能力的同时,注重提升本土的自主创新能力。     

浅谈企业知识管理

在知识经济时代 ,知识管理成为企业管理的重要课题。只有当企业充分认识到知识管理的重要性 ,自觉实施有效的知识管理 ,才能使企业在全球激烈的竞争环境中立于不败之地。因此 ,研究企业如何进行知识管理具有重要的理论价值和应用价值。本文从知识管理的涵义和特征入手 ,从几个方面研究企业知识管理的实施办法。     

基于核心能力的企业过程再造

阐述了企业过程再造(BPR)和核心能力的内涵及本质,分析了核心过程与核心能力二者之间的关系,指出企业过程再造不能脱离核心能力这一本质,BPR本质上应该是基于核心能力的再造。给出了基于核心能力实施BPR的6个具体步骤:即识别核心能力,识别核心过程,定义经营业绩,找出问题,确定方案和实施方案。     

论美术新课程教学过程的特征

新的《全日制义务教育美术课程标准(实验稿)》,要求美术教育以发展学生的艺术素养、人文素养及促进学生的发展为主要目标。新标准要求下的美术教育与传统美术教育相比,教学过程具有学生中心性、综合性、过程性、实践性、开放性、创造性、师生互动性、美育性、兴趣性和个性性等新的特征。     

Empirical Non-Parametric Control Charts: Estimation Effects and Corrections

Owing to the extreme quantiles involved, standard control charts are very sensitive to the effects of parameter estimation and non-normality. More general parametric charts have been devised to deal with the latter complication and corrections have been derived to compensate for the estimation step, both under normal and parametric models. The resulting procedures offer a satisfactory solution over a broad range of underlying distributions. However, situations do occur where even such a large model is inadequate and nothing remains but to consider non- parametric charts. In principle, these form ideal solutions, but the problem is that huge sample sizes are required for the estimation step. Otherwise the resulting stochastic error is so large that the chart is very unstable, a disadvantage that seems to outweigh the advantage of avoiding the model error from the parametric case. Here we analyse under what conditions non-parametric charts actually become feasible alternatives for their parametric counterparts. In particular, corrected versions are suggested for which a possible change point is reached at sample sizes that are markedly less huge (but still larger than the customary range). These corrections serve to control the behaviour during in-control (markedly wrong outcomes of the estimates only occur sufficiently rarely). The price for this protection will clearly be some loss of detection power during out-of-control. A change point comes in view as soon as this loss can be made sufficiently small.     

江泽民在实践哲学思想上的创新

江泽民同志的实践哲学思想,在继承邓小平实践哲学思想基础上,更具有新的时代特色。实事求是、与时俱进的创新思维是实践哲学思想的灵魂,贯穿于整个实践哲学体系;“三个代表”的思想是对实践标准的新发展,指明了社会主义实践和党的实践的基本目标;实践主体理论的创新,是实现社会主义实践基本目标的有力保障。     

基于Web的绿色制造系统

随着环境问题的日益严重，要求制造技术的发展必须与自然资源和环境相结合．由此提出了一个新的制造概念——绿色制造．本文对绿色制造的概念及其内容体系进行了论述，并就以web技术为支撑平台的绿色制造技术做了进一步地探讨．     

中小企业增长与发展的创新驱动

中小企业的增长与发展是两个既有联系又有区别的概念。增长需要创新,转化为发展时更需要创新作为张力。本文分析了中小企业创新系统并探讨了创新内容以及创新活动中应该注意的问题。     

成人依恋研究

依恋是人类适应生存的重要方式,是人类长期生物进化的结果,它会影响到成年后亲密关系的建立、人际社会功能的表达以及人格功能和人格特质的形成。目前成人依恋的研究大概可以分为两个方面:成人依恋的个体差异和成人依恋的检测维度。