期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
LAS Version 2.0数据格式解析 被引量:10
1
作者 周晓明 唐德瑾 +1 位作者 马秋禾 杨靖宇 《测绘工程》 CSCD 2010年第4期43-46,共4页
利用表格分析的方式,对比激光雷达系统(LIDAR)标准文件格式LAS version 2.0与旧版本verison1.1之间的异同,分析2.0版本的新特性,便于对LAS格式的理解和应用。新的定义标准更加适应LIDAR硬件间的通用性,给予用户更多的扩展空间,为LIDAR... 利用表格分析的方式,对比激光雷达系统(LIDAR)标准文件格式LAS version 2.0与旧版本verison1.1之间的异同,分析2.0版本的新特性,便于对LAS格式的理解和应用。新的定义标准更加适应LIDAR硬件间的通用性,给予用户更多的扩展空间,为LIDAR系统的应用提供高质量的文件交换基础。 展开更多
关键词 LIDAR LAS 头文件 变长记录 元数据块
下载PDF
Domain semantic mapping of database metasearch engine
2
作者 苗广祥 陈向阳 《Journal of Southeast University(English Edition)》 EI CAS 2007年第3期357-360,共4页
In order to implement semantic mapping of database metasearch engines, a system is proposed, which uses ontology as the organization form of information and records the new words not appearing in the ontology. When th... In order to implement semantic mapping of database metasearch engines, a system is proposed, which uses ontology as the organization form of information and records the new words not appearing in the ontology. When the new word' s frequency of use exceeds the threshold, it is added into the ontology. Ontology expansion is implemented in this way. The search process supports "and" and "or" Boolean operations accordingly. In order to improve the mapping speed of the system, a memory module is added which can memorize the recent query information of users and automatically learn the user' s query interest during the mapping which can dynamically decide the search order of instances tables. Experiments prove that these measures can obviously reduce the average mapping time. 展开更多
关键词 ONTOLOGY domain mapping database metasearch engine memory module
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部