Combining cardinal direction relations and other orientation relations in QSR
نویسنده
چکیده
We propose a calculus, cCOA, combining, thus more expressive than each of, two orientation calculi well-known in QSR: Frank’s projection-based cardinal direction calculus, CDA, and a coarser version, ROA, of Freksa’s relative orientation calculus. An original constraint propagation procedure, PcS4c+(), for cCOA-CSPs is presented, which aims at (1) achieving path consistency (Pc) for the CDA projection; (2) achieving strong 4-consistency (S4c) for the ROA projection; and (3) more (+) —the “+” consists of the implementation of the interaction between the two combined calculi. Dealing with the first two points is not new, and involves mainly the CDA composition table and the ROA composition table, which can be found in, or derived from, the literature. The originality of the propagation algorithm comes from the last point. Two tables, one for each of the two directions CDA-to-ROA and ROA-to-CDA, capturing the interaction between the two kinds of knowledge, are defined, and used by the algorithm. The importance of taking into account the interaction is shown with a real example providing an inconsistent knowledge base, whose inconsistency (a) cannot be detected by reasoning separately about each of the two components of the knowledge, just because, taken separately, each is consistent, but (b) is detected by the proposed algorithm, thanks to the interaction knowledge propagated from each of the two compnents to the other.
منابع مشابه
Combining Cardinal Direction Relations and Relative Relations in QSR
We propose a calculus, cCOA, combining, thus more expressive than each of, two orientation calculi well-known in QSR: Frank’s projection-based cardinal direction calculus, CDA, and a coarser version, ROA, of Freksa’s relative orientation calculus. An original constraint propagation procedure, PcS4c+(), for cCOA-CSPs is presented, which aims at (1) achieving path consistency (Pc) for the CDA pro...
متن کاملQualitative Spatial Reasoning about Internal Cardinal Direction Relations
A class of novel spatial relation, internal cardinal direction (ICD) relation, is introduced and discussed. Applying ICD-9 model, the characteristics and the simplification rule of ICD relations are discussed at first. Then the ICD related qualitative spatial reasoning is discussed in a formal way. Four composition cases are presented. They are 1) composing two nesting ICD relations and composi...
متن کاملCombining cardinal direction relations and relative orientation relations in Qualitative Spatial Reasoning
Combining different knowledge representation languages is one of the main topics in Qualitative Spatial Reasoning (QSR). Existing languages are generally incomparable in terms of expressive power; as such, their combination compensates each other’s representational deficiencies, and is seen as an answer to the emerging demand from real applications, such as Geographical Information Systems (GIS...
متن کاملIntegrating cardinal direction relations and other orientation relations in Qualitative Spatial Reasoning
Integrating different knowledge representation languages is one of the main topics in Qualitative Spatial Reasoning (QSR). Existing languages are generally incomparable in terms of expressive power; as such, their integration compensates each other’s representational deficiencies, and is seen by real applications, such as Geographic Information Systems (GIS), or robot navigation, as an answer t...
متن کاملCombining RCC-8 with Qualitative Direction Calculi: Algorithms and Complexity
Increasing the expressiveness of qualitative spatial calculi is an essential step towards meeting the requirements of applications. This can be achieved by combining existing calculi in a way that we can express spatial information using relations from both calculi. The great challenge is to develop reasoning algorithms that are correct and complete when reasoning over the combined information....
متن کامل