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轻量级空间合取查询应答使用关键词
Lightweight Spatial Conjunctive Query Answering using Keywords |
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| 课程网址: |
http://videolectures.net/eswc2013_schneider_conjunctive_query/
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| 主讲教师: |
Patrik Schneider
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| 开课单位: |
维也纳工业大学
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| 开课时间: |
2013-07-08
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| 课程语种: |
英语
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| 中文简介: |
随着可公开获得的地理空间数据的出现, 基于本体的空间数据访问 (obda) 越来越受到人们的关注。空间 dbms 用于实现地理信息系统 (gis), 适合管理大量数据和地理对象, 如点、线、多边形等。本文用空间对象扩展了描述逻辑 dl-lite, 并展示了如何通过本体 — 来回答空间配连查询 (scq), 即具有点集拓扑关系的连接查询, 如下一个和内部的点集拓扑关系 —用这种语言表达。此扩展的目标是使空间关系 dbms 能够在使用重写技术回答 scq 时, 数据源和地理对象存储在数据库中, 空间连接查询被重写为 sql 语句空间功能。此外, 我们还考虑对空间 obda 数据源进行基于关键字的查询, 并演示如何将表示为描述 scq 感兴趣对象的简单关键字列表的查询映射, 使用元模型完成具有空间方面的 scq。我们在一个原型中实现了空间 obda 的轻量级方法, 并使用相关项目中的数据源 (如开放街道地图和开放政府数据 vienna) 显示了初步实验结果。我们证明, 对于实际场景, 实际查询在元模型完成下是可以表达的, 查询应答在计算上是可行的。
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| 课程简介: |
With the advent of publicly available geospatial data, ontology-based data access (OBDA) over spatial data has gained increasing interest. Spatiorelational DBMSs are used to implement geographic information systems (GIS) and are fit to manage large amounts of data and geographic objects such as points, lines, polygons, etc. In this paper, we extend the Description Logic DL-Lite with spatial objects and show how to answer spatial conjunctive queries (SCQs) over ontologies—that is, conjunctive queries with point-set topological relations such as next and within —expressed in this language. The goal of this extension is to enable an off-the-shelf use of spatio-relational DBMSs to answer SCQs using rewriting techniques, where data sources and geographic objects are stored in a database and spatial conjunctive queries are rewritten to SQL statements with spatial functions. Furthermore, we consider keyword-based querying over spatial OBDA data sources, and show how to map queries expressed as simple keyword lists describing objects of interest to SCQs, using a meta-model for completing the SCQs with spatial aspects. We have implemented our lightweight approach to spatial OBDA in a prototype and show initial experimental results using data sources such as Open Street Maps and Open Government Data Vienna from an associated project. We show that for real-world scenarios, practical queries are expressible under meta-model completion, and that query answering is computationally feasible.
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| 关 键 词: |
计算机科学; 大数据; 语义网
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| 课程来源: |
视频讲座网
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| 最后编审: |
2020-06-08：wuyq
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| 阅读次数: |
39
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