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1.
The paper deals with the problem of using contours as the basis for defining probability distributions. First, the most general probability densities with given contours are obtained and the particular cases of circular and elliptical contours are dealt with. It is shown that the so-called elliptically contoured distributions do not include all possible cases. Next, the case of contours defined by polar coordinates is analyzed including its simulation and parameter estimation. Finally, the case of cumulative distribution functions with given contours is discussed. Several examples are used for illustrative purposes.  相似文献   
2.
While the concept of regular equivalence is equally applicable to dichotomous as well as valued networks, the identification of regular blocks in regular blockmodels is somewhat problematic when dealing with valued networks. Applying the standard procedure for identifying ties in such blockmodels, a procedure perhaps most suited for dichotomous networks, does tend to generate block images and reduced graphs that differ from intuitive notions of such structures.  相似文献   
3.
Repeated measurements designs are widely used in medicine, pharmacology, animal sciences, and psychology. In this article, some infinite series are developed to generate the balanced repeated measurements designs for p (periods) even. For p odd, construction procedures are also described. Catalogues of the proposed designs are also presented for p = 5, 7, 9, when v ≤ 100.  相似文献   
4.
哈尔滨从城市建筑伊始,虽受到较多的西方建筑文化熏染,但也存在中西融合共生的城市景观,并形成了以文庙、极乐寺中国传统建筑群为代表的历史街区。以这一历史街区的中国传统建筑风格流变作为研究对象。揭示这一历史街区的演化过程和主要建筑风貌特征。分析中国传统建筑风格在哈尔滨城市景观中的地位和发展势态。  相似文献   
5.
本文对生态经济、可持续发展经济、绿色经济、资源节约型社会、环境友好型社会、循环经济、低碳经济这七个概念,按口径分为三个层次,分别解说其内涵。根据我国科学发展的客观需要,结合上述三个层次的概念内涵,阐述我国可持续发展的战略取向。  相似文献   
6.
目前,我国中部地区在全国经济发展格局中呈现出发展水平低于东部,发展速度慢于西部的“塌陷”态势。针对这一情况,中央把中部崛起作为一个国家经济发展的重大战略提出来。中部地区要发展必须彻底改变传统经济的发展模式,而采用循环经济发展模式。通过对中部地区的经济社会现状进行分析,指出其发展循环经济的迫切性;得出其发展循环经济的相应对策。  相似文献   
7.
In the last decades, green and sustainable supply chain management practices have been developed, trying to integrate environmental concerns into organisations by reducing unintended negative consequences on the environment of production and consumption processes. In parallel to this, the circular economy discourse has been propagated in the industrial ecology literature and practice. Circular economy pushes the frontiers of environmental sustainability by emphasising the idea of transforming products in such a way that there are workable relationships between ecological systems and economic growth. Therefore, circular economy is not just concerned with the reduction of the use of the environment as a sink for residuals but rather with the creation of self-sustaining production systems in which materials are used over and over again.Through two case studies from different process industries (chemical and food), this paper compares the performances of traditional and circular production systems across a range of indicators. Direct, indirect and total lifecycle emissions, waste recovered, virgin resources use, as well as carbon maps (which provide a holistic visibility of the entire supply chain) are presented. The paper asserts that an integration of circular economy principles within sustainable supply chain management can provide clear advantages from an environmental point view. Emerging supply chain management challenges and market dynamics are also highlighted and discussed.  相似文献   
8.
本文讨论了基于数字微镜系统(DMD)的环形光栅的设计和制作方法。利用DMD系统,我们可以制作出低成本、半径可调的环形光栅,为使其集成到微光机电系统提供了一种可能。通过实验,我们获得了最大外半径为42.7μm的环形光栅。  相似文献   
9.
Rank tests are considered that compare t treatments in repeated measures designs. A statistic is given that contains as special cases several that have been proposed for this problem, including one that corresponds to the randomized block ANOVA statistic applied to the rank transformed data. Another statistic is proposed, having a null distribution holding under more general conditions, that is the rank transform of the Hotelling statistic for repeated measures. A statistic of this type is also given for data that are ordered categorical rather than fully rankedo Unlike the Friedman statistic, the statistics discussed in this article utilize a single ranking of the entire sample. Power calculations for an underlying normal distribution indicate that the rank transformed ANOVA test can be substantially more powerful than the Friedman test.  相似文献   
10.
东濮凹陷断裂复杂,多断块、多套生储盖组合,叠后偏移成像效果不佳。叠前时间偏移技术在这一复杂断块区的应用可以改善成像效果。研究提出了一套以速度迭代为核心、地质信息为约束的求取偏移速度场的改进方法,提高了偏移速度的精度;通过对偏移孔径、最大偏移角度、射线路径、去假频4个关键参数处理的分析,得出适合东濮凹陷地震资料特点的经验参数,减少了以后处理过程中的试验工作量和参数试验的盲目性,有效地提高了处理效率。通过叠前时间偏移,提高了复杂断块地区成像精度,能够准确地落实断层位置和认识断块之间的关系,与井资料的吻合程度较高,取得了明显的地质效果。  相似文献   
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