经济转型背景下日本贸易技术结构的演进研究——基于1960-1988年数据的实证分析

贸易结构是一国产业结构的反映,对一国产业结构也会带来一定的影响。依据经合组织的技术密集度标准,将日本的进出口商品进行分类。在此基础上,分析了日本贸易结构技术构成的演进。研究发现,战后日本的出口结构出现了持续、明显的升级,进口则集中在中技术与低技术产业。随着日本经济的发展,影响贸易结构的因素以及进出口结构之间的关联均发生了明显的变化。     

一种改进的可靠性分配方法及其应用验证

可靠性分配是系统设计中的重要工作,常用的可靠性分配方法如AGREE分配法、评分分配法对影响可靠性指标的因素考虑不全,并且都是针对串联系统的。利用贝叶斯网络在不确定性概率推理方面的优势,将传统的故障树转化为贝叶斯网络求解最小割集和底事件重要度。建立了改进的可靠性分配模型,首先将顶层可靠性指标在最小割集之间分配,然后根据底事件重要度和评分将最小割集对应的可靠性指标分配到底事件。以某型飞机电传操纵系统可靠性指标分配为例,仿真结果表明,贝叶斯网络相对于故障树分析计算底事件重要度更为简单、精度更高。改进的分配方法能够考虑影响可靠性指标的主要因素,实现指标的科学分配。     

长历时暴雨强度公式的推求方法

近年来,随着极端暴雨事件的出现,导致城市内涝灾害频繁发生,原有降雨历时仅为2h的市政排水设计暴雨强度公式已无法满足城市暴雨设计的需求,因此就要延长暴雨采样历时,推求出长历时(24h)暴雨强度公式。针对以上问题,根据北京市提供的52a(1961-2012)原始降雨资料并进行数字化处理,结合水利的长历时特点,采用兼顾市政排水,水利排涝,内涝防治的采样方法,应用P-Ⅲ分布曲线进行频率分析后采用6种经典方法推求暴雨强度公式的参数值,优选出误差最小且满足规范要求的暴雨强度公式参数值,进而推求长历时暴雨强度公式,在此基础上与短历时暴雨强度公式比较,分析两者的差异,为城市雨水排除规划设计提供科学依据和参考。     

Unfolding intensity function of a Poisson process in models with approximately specified folding operator

Quasi-maximum likelihood histogram sieve estimators of the intensity function of an indirectly observed Poisson process are studied. The setup differs from the standard one in that the exact form of the folding operator may not be known. Instead, approximate knowledge on its discretized version is available. Conditions for strong L ²-consistency are given and admissible discretization rates are studied. In non-folding problems, the number of histogram bins may essentially increase at the usual maximal rate while folding reduces the allowed discretization rates. It is shown that, even in moderately ill-posed problems, the discretization effects may be critical for the strong L ²-convergence and that there is an essential need both for further regularization and for imposing stronger conditions on the estimated function. Not surprisingly, the most restrictive factor is the low approximation power of piecewise constant functions. A regularization method is proposed which suitably modifies the discrete approximation of the folding operator and ensures the strong consistency. Since no penalty term is being introduced, the EM algorithm can be used in its factorized, efficient form. Convergence rates are obtained in terms of the discrete problem. Received: July 1999     

起落航线训练目视飞行下跑道容量评估

对混合运输的机场来说,运输飞行的效率与起落航线上的飞行训练的效率是互相影响的。为了做出此类型下的跑道容量评估,提出考虑起落航线训练目视飞行下的跑道容量评估模型。该模型考虑了训练飞行目视间隔对起飞间隔的影响,抽象航空器占用跑道时的运行过程,以目视间隔为关键因素,在此基础上分析讨论运输类型以及机型对跑道容量的影响。使用Anylogic进行仿真计算,结果表明使用目视间隔可以大幅提升跑道服务能力,容量提升了55%左右,验证了该方法和模型的有效性。     

湖南省雷暴地闪特征初步分析

利用湖南省1980-2010年雷暴日数据、2008-2013年闪电数据,分析了湖南省雷暴和闪电变化特征。结果表明:湖南省属于雷暴多发区,年平均雷暴日数分布呈南高北低的趋势,沿雪峰山有个相对高值区,平均雷暴日数在30d到70d之间。湖南省6年的年平均闪电条数35万余条,雷电高发时段为4-9月,其中7月是全年闪电活动最密集的月份。春季(3-5月)闪电逐时分布呈现双峰型,高峰值出现在02时、17时,夏季(6-8月)闪电多集中在下午15-17时,秋季(9月)高峰期集中在15-16时。湖南省闪电密度分布和闪电强度分布,高值区均在娄底、郴州,全省闪电主要强度分布在20-80kA。     

基于OpenGL的导弹飞行仿真的实现

本文对导弹飞行以及被炮弹攻击的过程进行了仿真,主要介绍了如何在VC环境下,利用Open GL图形库技术实现导弹飞行仿真的方法和具体实现过程。     

An Investigation of the Relation between Cooperation Intensity and the Innovative Success of German Regions

Abstract

Concepts like regional innovation systems, innovative milieu and learning regions emphasise the positive contribution of intra-regional cooperation to firms’ innovation performance. This claim is, however, primarily backed by qualitative evidence, as few studies test this issue with quantitative approaches. Using data on co-application and co-invention of patents for 270 German labour market regions, this study shows that cooperation intensity and regions’ innovation efficiency are empirically associated in a negative way. This particularly concerns missing or very extensive inter-regional cooperation. In contrast, medium intensities of regional cooperation have rather positive effects.     

要素密集型逆转与贸易获利能力提升——以中美纺织业为例

本文运用灰色聚类法并以中美纺织业为例,研究了产业生产要素密集型的逆转与贸易获利能力的提升问题。研究表明:以2000年中国制造业作为衡量标准,美国的纺织业在2003年从劳动密集型产业逆转成为技术密集型产业,而中国的纺织产业在考察期间一直为劳动密集型产业。文章进一步分析了要素密集型逆转的动因及贸易利得效应,发现在发生要素密集型逆转后美国纺织出口企业的获利能力明显大于中国,表明通过要素密集型逆转实现产业内升级是一条可行的路径选择。     

Corporate environmental performance evaluation: a measurement model and a new concept

While many third‐party organizations are practically evaluating corporate environmental performance (CEP), few academic studies have paid attention to third‐party environmental performance evaluation (EPE). To answer the question of what should be measured for third‐party EPE, we develop an environmental performance measurement (EPM) model consisting of environmental management performance (EMP) and environmental operational performance (EOP), and hypothesize that EMP be measured by four management performance indicators (MPIs: organizational system, stakeholder relations, operational countermeasures and environmental tracking) and EOP be measured by two operational performance indicators (OPIs: inputs and outputs). Further, to answer the question of how to enable third‐party EPE comparable across companies from different (sub‐)sectors, we propose to use the environmental intensity change index (EICI) as a measure of OPIs. Empirical tests confirm that the EICI and the evaluation based on it are comparable across companies from different sub‐sectors. Empirical tests also support the existence of the MPIs and OPIs and the two‐dimensioned constructs of CEP. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.