With the development of information technology, the amount of power grid topology data has gradually increased. Therefore, accurate querying of this data has become particularly important. Several researchers have cho...With the development of information technology, the amount of power grid topology data has gradually increased. Therefore, accurate querying of this data has become particularly important. Several researchers have chosen different indexing methods in the filtering stage to obtain more optimized query results because currently there is no uniform and efficient indexing mechanism that achieves good query results. In the traditional algorithm, the hash table for index storage is prone to "collision" problems, which decrease the index construction efficiency. Aiming at the problem of quick index entry, based on the construction of frequent subgraph indexes, a method of serialized storage optimization based on multiple hash tables is proposed. This method mainly uses the exploration sequence to make the keywords evenly distributed; it avoids conflicts of the stored procedure and performs a quick search of the index. The proposed algorithm mainly adopts the "filterverify" mechanism; in the filtering stage, the index is first established offline, and then the frequent subgraphs are found using the "contains logic" rule to obtain the candidate set. Experimental results show that this method can reduce the time and scale of candidate set generation and improve query efficiency.展开更多
现有的中文事件抽取方法存在触发词和论元依赖建模不足的问题,削弱事件内的信息交互,导致论元抽取性能低下,特别是论元角色存在重叠的情况下.对此,文中提出基于图注意力和表指针网络的中文事件抽取方法(Chinese Event Extraction Method...现有的中文事件抽取方法存在触发词和论元依赖建模不足的问题,削弱事件内的信息交互,导致论元抽取性能低下,特别是论元角色存在重叠的情况下.对此,文中提出基于图注意力和表指针网络的中文事件抽取方法(Chinese Event Extraction Method Based on Graph Attention and Table Pointer Network,ATCEE).首先,融合预训练字符向量和词性标注向量作为特征输入,并利用双向长短期记忆网络,得到事件文本的强化语义特征.再将字符级建模的依存句法图引入图注意力网络,捕获文本中各组成成分的长距离依赖关系.然后,使用表填充的方法进行特征融合,进一步增强触发词和其对应的所有论元之间的依赖性.最后,将学习得到的表特征输入全连接层和表指针网络层,进行触发词和论元的联合抽取,使用表指针网络对论元边界进行解码,更好地识别长论元实体.实验表明:ATCEE在ACE2005和DuEE1.0这两个中文基准数据集上都有明显的性能提升,并且字符级依存特征和表填充策略在一定程度上可以解决论元角色重叠问题.ATCEE源代码地址如下:https://github.com/event6/ATCEE.展开更多
多层卫星网络的拓扑结构具有明显的时变特征,难以提供持续且稳定的端到端路径,导致高效路由问题面临着巨大的挑战.将卫星网络设计为封闭的体系结构,采用强管理或调度式控制策略会导致其无法自由、高效地实现与其它系统的协同组网.基于I...多层卫星网络的拓扑结构具有明显的时变特征,难以提供持续且稳定的端到端路径,导致高效路由问题面临着巨大的挑战.将卫星网络设计为封闭的体系结构,采用强管理或调度式控制策略会导致其无法自由、高效地实现与其它系统的协同组网.基于IP的网络体系结构在应用于多层卫星网络时又存在路由效率不高的问题.基于命名数据网络NDN(Named Data Networking)体系结构,提出一种多层卫星网络分布式路由方法——SNDN(Satellite Named Data Networking).根据链路切换的周期性和可预知性,以时变图为建模工具,设计一个能自适应稠密和稀疏场景的路由算法来动态地计算时间相关的最快路径并附加为源路由信息,充分利用命名数据网络数据驱动的通信模式、数据包级的安全特性和逐跳转发的特点,由节点在包转发的过程中动态地完成转发表(FIB,Forwarding Information Base)和请求状态表(PIT,Pending Interest Table)的构建.可为面向未来空、天、地一体化协同组网的多层卫星网络路由研究提供一种新的思路.通过仿真实验及对比分析,验证了SNDN在路由效率和多播性能方面的优势.展开更多
基金supported by the State Grid Science and Technology Project (Title: Research on High Performance Analysis Technology of Power Grid GIS Topology Based on Graph Database, 5455HJ160005)
文摘With the development of information technology, the amount of power grid topology data has gradually increased. Therefore, accurate querying of this data has become particularly important. Several researchers have chosen different indexing methods in the filtering stage to obtain more optimized query results because currently there is no uniform and efficient indexing mechanism that achieves good query results. In the traditional algorithm, the hash table for index storage is prone to "collision" problems, which decrease the index construction efficiency. Aiming at the problem of quick index entry, based on the construction of frequent subgraph indexes, a method of serialized storage optimization based on multiple hash tables is proposed. This method mainly uses the exploration sequence to make the keywords evenly distributed; it avoids conflicts of the stored procedure and performs a quick search of the index. The proposed algorithm mainly adopts the "filterverify" mechanism; in the filtering stage, the index is first established offline, and then the frequent subgraphs are found using the "contains logic" rule to obtain the candidate set. Experimental results show that this method can reduce the time and scale of candidate set generation and improve query efficiency.
文摘现有的中文事件抽取方法存在触发词和论元依赖建模不足的问题,削弱事件内的信息交互,导致论元抽取性能低下,特别是论元角色存在重叠的情况下.对此,文中提出基于图注意力和表指针网络的中文事件抽取方法(Chinese Event Extraction Method Based on Graph Attention and Table Pointer Network,ATCEE).首先,融合预训练字符向量和词性标注向量作为特征输入,并利用双向长短期记忆网络,得到事件文本的强化语义特征.再将字符级建模的依存句法图引入图注意力网络,捕获文本中各组成成分的长距离依赖关系.然后,使用表填充的方法进行特征融合,进一步增强触发词和其对应的所有论元之间的依赖性.最后,将学习得到的表特征输入全连接层和表指针网络层,进行触发词和论元的联合抽取,使用表指针网络对论元边界进行解码,更好地识别长论元实体.实验表明:ATCEE在ACE2005和DuEE1.0这两个中文基准数据集上都有明显的性能提升,并且字符级依存特征和表填充策略在一定程度上可以解决论元角色重叠问题.ATCEE源代码地址如下:https://github.com/event6/ATCEE.
文摘多层卫星网络的拓扑结构具有明显的时变特征,难以提供持续且稳定的端到端路径,导致高效路由问题面临着巨大的挑战.将卫星网络设计为封闭的体系结构,采用强管理或调度式控制策略会导致其无法自由、高效地实现与其它系统的协同组网.基于IP的网络体系结构在应用于多层卫星网络时又存在路由效率不高的问题.基于命名数据网络NDN(Named Data Networking)体系结构,提出一种多层卫星网络分布式路由方法——SNDN(Satellite Named Data Networking).根据链路切换的周期性和可预知性,以时变图为建模工具,设计一个能自适应稠密和稀疏场景的路由算法来动态地计算时间相关的最快路径并附加为源路由信息,充分利用命名数据网络数据驱动的通信模式、数据包级的安全特性和逐跳转发的特点,由节点在包转发的过程中动态地完成转发表(FIB,Forwarding Information Base)和请求状态表(PIT,Pending Interest Table)的构建.可为面向未来空、天、地一体化协同组网的多层卫星网络路由研究提供一种新的思路.通过仿真实验及对比分析,验证了SNDN在路由效率和多播性能方面的优势.
