为满足大数据实时处理的需求,提出了一种基于划分的关联规则并行分层挖掘算法(Parallel Hierarchical Association Rule Mining,PHARM)。首先,将整个数据库D随机分割成若干个非重叠区域,并行挖掘出局部频繁项集;然后利用先验性质,连接...为满足大数据实时处理的需求,提出了一种基于划分的关联规则并行分层挖掘算法(Parallel Hierarchical Association Rule Mining,PHARM)。首先,将整个数据库D随机分割成若干个非重叠区域,并行挖掘出局部频繁项集;然后利用先验性质,连接局部频繁项集得全局候选项集;再次扫描D统计出每个候选项集的实际支持度,以确定全局频繁项集。最后,建模分析了该算法的高效性。展开更多
Objective To evaluate the environmental and technical efficiencies of China＇s industrial sectors and provide appropriate advice for policy makers in the context of rapid economic growth and concurrent serious environ...Objective To evaluate the environmental and technical efficiencies of China＇s industrial sectors and provide appropriate advice for policy makers in the context of rapid economic growth and concurrent serious environmental damages caused by industrial pollutants. Methods A data of envelopment analysis （DEA） framework crediting both reduction of pollution outputs and expansion of good outputs was designed as a model to compute environmental efficiency of China＇s regional industrial systems. Results As shown by the geometric mean of environmental efficiency, if other inputs were made constant and good outputs were not to be improved, the air pollution outputs would have the potential to be decreased by about 60% in the whole China. Conclusion Both environmental and technical efficiencies have the potential to be greatly improved in China, which may provide some advice for policy-makers.展开更多
文摘为满足大数据实时处理的需求,提出了一种基于划分的关联规则并行分层挖掘算法(Parallel Hierarchical Association Rule Mining,PHARM)。首先,将整个数据库D随机分割成若干个非重叠区域,并行挖掘出局部频繁项集;然后利用先验性质,连接局部频繁项集得全局候选项集;再次扫描D统计出每个候选项集的实际支持度,以确定全局频繁项集。最后,建模分析了该算法的高效性。
文摘Objective To evaluate the environmental and technical efficiencies of China＇s industrial sectors and provide appropriate advice for policy makers in the context of rapid economic growth and concurrent serious environmental damages caused by industrial pollutants. Methods A data of envelopment analysis （DEA） framework crediting both reduction of pollution outputs and expansion of good outputs was designed as a model to compute environmental efficiency of China＇s regional industrial systems. Results As shown by the geometric mean of environmental efficiency, if other inputs were made constant and good outputs were not to be improved, the air pollution outputs would have the potential to be decreased by about 60% in the whole China. Conclusion Both environmental and technical efficiencies have the potential to be greatly improved in China, which may provide some advice for policy-makers.
