From secondary causes to artificial instruments: Pierre-Sylvain Régis's rethinking of scholastic accounts of causation

Although several of Descartes's disciples established occasionalism as the natural outcome of Cartesianism, Pierre-Sylvain Régis forcefully resisted this conclusion by developing an account of secondary causes in which God does not immediately intervene in the natural world. In order to understand this view, it has been argued that Régis melds Aquinas's concurrentism with the new, mechanist natural philosophy defended in Cartesian physics. In this paper, I contend that such a reading of Régis's position is misleading for our understanding of both his account of secondary causality and the relationship between medieval debates and seventeenth century natural philosophy. I show that Régis's account of secondary causality denies two fundamental features at the core of the account proposed by Aquinas, namely that God acts immediately in nature and that secondary causes are per se causes. I contend that Régis's view more closely resembles a specific account of artificial instrumental causality developed by Duns Scotus. The comparison with Scotus shows that Régis is still dealing with conceptual tools that can be traced back to the scholastic tradition. Yet, Régis implements these tools to establish an account of causation that is fundamentally irreconcilable with scholastic natural philosophy.     

改进的单亲遗传算法在汇水盆地三维建模中的应用研究

汇水盆地在地球化学等领域的研究中占有重要地位，但在利用计算机对其进行建模时，根据其传统定义却很难对汇水盆地进行自动提取，因此给出了一个基于点的汇水盆地定义，并针对此定义的特点，提出了一种改进的单亲遗传算法。此算法引入“宽容选择”等机制，简化了遗传操作过程，提高了计算效率，且不要求初始群体的多样性，也有效地克服了“早熟收敛”现象。算法很好地解决了以往用爬山算法对汇水盆地进行三维建模时陷入局部极小点而无法绘制出比较完整的；汇水盆地的问题；在进行比较实验时，也证明该算法是十分有效的。     

城市灾害应急预案GIS模型初探

以城市灾害应急事件的应对和处置问题为研究内容,从城市灾害事件的一般特征、可能产生的影响、需要处置的事项和处置组织指挥对策出发,研究建立事件应急处置预案需要的相关信息、信息分析方法与过程、对策制定以及组织指挥地理信息模型体系。以城市天然气管道泄漏事件为例,阐述根据事件发生的少量报案信息触发模型,迅速及时进行事件分析评估和快速对策制定,并生成抢险救援组织指挥方案的基本过程．