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arXiv 0909.0138cs.AI
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扩展对象间基本方向的推理

Reasoning about Cardinal Directions between Extended Objects

Centre for Quantum Computation and Intelligent Systems, Faculty of Engineering and Information Technology, University of Technology, Sydney(悉尼科技大学工程与信息技术学院量子计算与智能系统中心);Department of Computer Science and Technology, Tsinghua University(清华大学计算机科学与技术系)

Xiaotong Zhang, Weiming Liu, Sanjiang Li, Mingsheng Ying

摘要:

扩展空间对象之间的方向关系是重要的常识性知识。最近,Goyal和Egenhofer提出了一个正式的模型,称为基数方向演算(CDC),用于表示连接的平面区域之间的方向关系。CDC可能是方向信息最具表现力的定性演算,并且已经吸引了诸如人工智能、地理信息科学和图像检索等领域越来越多的兴趣。给定一个CDC约束的网络,一致性问题是决定该网络是否可由实平面中的连通区域实现。本文给出了一个检验基本CDC约束网络一致性的立方算法,并证明了用CDC进行推理一般是NP完全问题。对于基本CDC约束的一致网络,我们的算法还在立方时间内返回“规范”解决方案。这种立方算法也适用于处理可能不连通的区域之间的基本方向,在这种情况下,目前最好的算法是时间复杂度O(n^5)。

英文摘要:

Direction relations between extended spatial objects are important commonsense knowledge. Recently, Goyal and Egenhofer proposed a formal model, known as Cardinal Direction Calculus (CDC), for representing direction relations between connected plane regions. CDC is perhaps the most expressive qualitative calculus for directional information, and has attracted increasing interest from areas such as artificial intelligence, geographical information science, and image retrieval. Given a network of CDC constraints, the consistency problem is deciding if the network is realizable by connected regions in the real plane. This paper provides a cubic algorithm for checking consistency of basic CDC constraint networks, and proves that reasoning with CDC is in general an NP-Complete problem. For a consistent network of basic CDC constraints, our algorithm also returns a 'canonical' solution in cubic time. This cubic algorithm is also adapted to cope with cardinal directions between possibly disconnected regions, in which case currently the best algorithm is of time complexity O(n^5).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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