Research On Spatial Directional Relations Models And Combined Spatio-temporal Reasoning

Content:Researching on spatial relation between spatial objects plays the important role in qualitative spatial reasoning, GIS and computer vision. Spatial relation is the relation with spatial character between spatial object, it usually consists of topological relations, order relations and metric relations etc. Directional relation is one of order relations, is one of the most elementary relation in space, also the basic aspect of spatial reasoning. Directional relations describe where objects are placed relative to reference objects, usually orientational nouns are used to represent the order relation between spatial objects. Researching on directional relation is an important topic in qualitative spatial reasoning. Now the research of directional relation is focus on the directional relation of determinate objects. The existent formal description and reasoning models of spatial relation are limited in combining multi-spatial relations and representation and reasoning of directional relation between indeterminate regions.The successful research of qualitative representation and reasoning in the individual field of space and time and the urgent requests for representation and reasoning of the integration of space and time in application lead to the research of spatio-temporal reasoning which simultaneously supports space and time. Spatio-temporal reasoning is the reasoning of the objects that take the space and change with time. Its research includes the representation, modeling and reasoning of spatial, temporal and spatio-temporal information. Spatio-temporal reasoning has now become a hot spot in the relative research field such as Artificial Intelligence, GIS, and Image Understanding Spatio-temporal database. In representation and reasoning of combining spatial and temporal relations, most researching are focus on combining topological space logic and temporal logic,researching on integrating other spatial relations and temporal relation are not seen.This thesis is focused on some hot spot problems in spatio-temporal reasoning. The research works in spatial, temporal and spatio-temporal reasoning, especially the works of spatio-temporal logic, are surveyed, and some feasible plans are proposed. Existed directional relation models are researched, problems and future works are also analyzed. Interplays of directional and topological relations between spatial objects are analyzed, and qualitative spatial reasoning method of combining directional and topological relations to representation of spatial arrange are proposed. Based on interval value and its operational properties, directional relation model of indetermined regions is given. From the point of view of semantic, spatio-temporal logic that integrating metric space logic and proposidonal temporal logic are presented. Besides, the thesis proposes a qualitative spatio-temporal representation and reasoning method deals with combining position relations and time.The main contributions and results included in the thesis are as follows:Firstly, the thesis summarizes and analyses the state of arts in spatio-temporal reasoning based on the integration of spatial and temporal theory. The research works in spatial, temporal and spatio-temporal reasoning are surveyed and analyzed.Secondly, the overview of state of arts in spatio-temporal logic is given. The international research works in spatio-temporal logic are summarized, which include spatial topological logic, spatial metric logicm the integration of metric and topological logic, Allen^s temporal interval logic, propositional temporal logic, and spatio-temporal logic based on linear time, branching time, interval time. Their computational properties are analyzed here, and the existent problems and future emphasizing research works are pointed out.Thirdly, directional relation models of spatial objects are discussed, representation and reasoning of directional relations based on point and region separately are given, and the directional relation model between indeterminate regions is analyses. Directional relation models were classified and compared. The existent problems and future emphasizing research works are pointed out.Fourthly, interplay of cardinal directional and topological relations is investigated in this thesis. The existent model can only consider single relation of cardinal directional or topological relation, not considering the interdependence of the two relations. Based on Allen's interval relations, a common representation scheme for two spatial relations isproposed, and their composition operations are studied. The thesis proposed a reasoning algorithm for this task that take into account the interrelation of qualitative cardinal direction information and topological information. Because of the representative limitation of bounding box of reference object by existed cardinal directional relation models, a detailed partition approach of bounding box of reference object is given, and a set of rules are also proposed that can infer topological relations from interior cardinal directional relations.Fifthly, the thesis expatiates the model of directional relations between indeterminate regions in detail. A new method of directional relations between indeterminate spatial regions based on the operation property of interval value is given after analyzing existing models. It analyzes membership grade of direction relation between indeterminate regions using interval value direction relation matrix. Directional relation between indeterminate regions is divided into four types: directional relation between two crisp regions, directional relation between crisp region and indeterminate region, directional relation between indeterminate region and crisp region, directional relation between two indeterminate regions. This model can uniformly deal with crisp regions as a specific case of indeterminate regions.Sixthly, spatio-temporal logic model combining space metric logic and temporal logic is investigated. The thesis uses multi-dimensional logics as frameworks for knowledge representation and, constructs two-dimensional logics intended for describing metric relationships that change over time. The family logic, named