语义查询扩展中,关键一步是扩展词的选择方法和扩展词权重的计算。提出一种改进的LCA(局部上下文分析法):OLCA(Optimize Local Context Analysis)。OLCA应用于分权重的多关键字查询中,结合WordNet概念树,从语义和实际查询语料两方面对...语义查询扩展中,关键一步是扩展词的选择方法和扩展词权重的计算。提出一种改进的LCA(局部上下文分析法):OLCA(Optimize Local Context Analysis)。OLCA应用于分权重的多关键字查询中,结合WordNet概念树,从语义和实际查询语料两方面对初始查询词进行扩展,并根据初始查询词中多个关键词的位置,结合扩展候选集中词间关系计算修正各扩展词的权重。实验证明,与单独基于统计或基于语义的查询扩展方法相比,其查准率和查全率均有较大提高。展开更多
Deep rock mass possesses some unusual properties due to high earth stress,which further result in new problems that have not been well understood and explained up to date.In order to investigate the deformation mechan...Deep rock mass possesses some unusual properties due to high earth stress,which further result in new problems that have not been well understood and explained up to date.In order to investigate the deformation mechanism,the complete deformation process of deep rock mass,with a great emphasis on local shear deformation stage,was analyzed in detail.The quasi continuous shear deformation of the deep rock mass is described by a combination of smooth functions:the averaged distribution of the original deformation field,and the local discontinuities along the slip lines.Hence,an elasto-plastic model is established for the shear deformation process,in which the rotational displacement is taken into account as well as the translational component.Numerical analysis method was developed for case study.Deformation process of a tunnel under high earth stress was investigated for verification.展开更多
文摘语义查询扩展中,关键一步是扩展词的选择方法和扩展词权重的计算。提出一种改进的LCA(局部上下文分析法):OLCA(Optimize Local Context Analysis)。OLCA应用于分权重的多关键字查询中,结合WordNet概念树,从语义和实际查询语料两方面对初始查询词进行扩展,并根据初始查询词中多个关键词的位置,结合扩展候选集中词间关系计算修正各扩展词的权重。实验证明,与单独基于统计或基于语义的查询扩展方法相比,其查准率和查全率均有较大提高。
基金Project(50825403) supported by the National Science Fund for Distinguished Young ScholarsProject(2010CB732003) supported by the National Key Basic Research Program of ChinaProject(51021001) supported by the Science Fund for Creative Research Group of the National Natural Science Foundation of China
文摘Deep rock mass possesses some unusual properties due to high earth stress,which further result in new problems that have not been well understood and explained up to date.In order to investigate the deformation mechanism,the complete deformation process of deep rock mass,with a great emphasis on local shear deformation stage,was analyzed in detail.The quasi continuous shear deformation of the deep rock mass is described by a combination of smooth functions:the averaged distribution of the original deformation field,and the local discontinuities along the slip lines.Hence,an elasto-plastic model is established for the shear deformation process,in which the rotational displacement is taken into account as well as the translational component.Numerical analysis method was developed for case study.Deformation process of a tunnel under high earth stress was investigated for verification.
