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雹云识别是一个多参数的模式识别问题,应用物元可拓思想将单参数雹云识别的不相容性转化为相容性问题。在与成都地区雹云识别的物元可拓模型进行对比后,根据低纬高原地形及气候特点,通过适当增加参数,构造完成低纬高原雹云识别的物元可拓模型,以此进行雹云识别,准确率达86%以上。 相似文献
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Richard D. Hey 《地球表面变化过程与地形》1979,4(2):179-182
The concept of causality has been a fundamental principle of scientific investigation for many centuries. Recently, however, there has been a significant reappraisal of the philosophical basis of the concept of causality and this has important implications for future geomorphological research. It is now recognized that there are two approaches to the study of relations between variables. Conventionally knowledge was divided into classes and, on the basis of time precedence, causal relations were defined. While this approach enables static systems to be analysed it does not apply to dynamic systems which exhibit mutual causality. This traditional view of knowledge became obsolete with the introduction of the concept of the continuum. Algebraic techniques now enable the solution of systems of simultaneous equations, provided that there are as many equations as unknowns. Significantly this approach applies to dynamic as well as static systems. Further advances in fluvial geomorphological research are dependent on the adoption of mathematical reasoning. This will concentrate research on the mode and rate of operation of channel processes and feedback mechanisms. Given this information it will be possible to develop a static process-response model to explain and predict channel response to a set of input conditions, and a dynamic model to simulate channel development through time and space. 相似文献
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Multilevel models for analyzing people’s daily movement behavior 总被引:1,自引:0,他引:1
A survey on the daily movement behavior of the people residing in the territory of the Municipality of Pisa, Italy, was carried
out in October 2002. This work is aimed at modeling the distance covered and the number of trips taken in a day as functions
of several individual characteristics. In order to take the potential intra-family and intra-area correlation of the observations
into account, multilevel models are estimated. We use two and three level hierarchical linear and Poisson models to estimate
the number of daily trips taken by an individual. Likelihood ratio tests indicate the movement behavior in 1 day is more alike
for individuals within a family than for individuals from different families. 相似文献
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在建立区域城市化水平评价指标体系的基础上,运用物元可拓方法和主成分分析方法,以福建省23个主要城市为研究地域单元,建立了福建省区域城市化水平综合评判模型.模型的输出结果表明,福建省区域城市化水平总体偏低,各地区在发展水平上出现明显分层;模型的综合关联度将福建省区域城市化水平划分成4个等级,分项指标关联度则揭示了各地区城市化发展的薄弱环节.研究结果较为客观地反映了福建省城市化的实际状况,为区域城市化水平的评价提供了一种新的研究思路. 相似文献
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