intersection model is the most popular framework used for formalizing the spatial relations between two spatial objects A and B. It transforms the topological relation- ships between two simple spatial Objects A and B...intersection model is the most popular framework used for formalizing the spatial relations between two spatial objects A and B. It transforms the topological relation- ships between two simple spatial Objects A and B into point-set topology problem in terms of the intersections of A’s boundary ( A), interior (A0) and exterior (A - ) with B’s bound- ary ( B), interior (B0) and exterior (B - ). It is shown in this paper that there exist some limitations of the original 9-intersection model due to its definition of an object’s exterior as its complement,and it is difficult to distinguish different disjoint relations and relations be- tween complex objects with holes, difficult or even impossible to compute the intersections with the two object’s complements ( A B -, A0 B -, A - B, A - B0 and A - B - )since the complements are infinitive. The authors suggest to re-define the exterior of spa- tial object by replacing the complement with its Voronoi region. A new Voronoi-based 9-in- tersection (VNI) is proposed and used for formalizing topological relations between spatial objects. By improving the 9-interscetion model, it is now possible to distinguish disjoint rela- tions and to deal with objects with holes. Also it is possible to compute the exterior-based in- tersections and manipulate spatial relations with the VNI.展开更多
Five lengthy periods involving multiple phases of cordierite and andalusite growth were revealed by detailed studies of foliation inflection/intersection axes （FIA） preserved in porphyroblasts in schists from the Ar...Five lengthy periods involving multiple phases of cordierite and andalusite growth were revealed by detailed studies of foliation inflection/intersection axes （FIA） preserved in porphyroblasts in schists from the Arkansas River region in Colorado, USA. The regionally consistent character of the succession of five different FIA trends enabled the relative timing of each FIA with respect to the next to be determined. The FIA succession from first to last is： FIA 1 trending W-E, FIA 2 trending SSW- NNE, FIA 3 trending NNW-SSE, FIA 4 trending NW-SE and FIA 5 trending SW-NE. For four of the FIA sets, samples were found containing monazite grains preserved as inclusions. These were dated on an electron microprobe. The ages obtained concur exactly with the FIA succession, with FIA 1 at 1506±15 Ma, FIA 2 at 1467±23 Ma, FIA 3 at 1425±18 Ma, FIA 4 not dated and FIA 5 at 1366±20 Ma. These ages are directly reflected in a succession of plutons in the surrounding region dated by other isotopic approaches, suggesting that deformation, metamorphism and pluton emplacement occurred together episodically, but effectively continuously, for some 140 Ma.展开更多
基金Project supported by the National Natural Science Foundation of China(No.49471059)
文摘intersection model is the most popular framework used for formalizing the spatial relations between two spatial objects A and B. It transforms the topological relation- ships between two simple spatial Objects A and B into point-set topology problem in terms of the intersections of A’s boundary ( A), interior (A0) and exterior (A - ) with B’s bound- ary ( B), interior (B0) and exterior (B - ). It is shown in this paper that there exist some limitations of the original 9-intersection model due to its definition of an object’s exterior as its complement,and it is difficult to distinguish different disjoint relations and relations be- tween complex objects with holes, difficult or even impossible to compute the intersections with the two object’s complements ( A B -, A0 B -, A - B, A - B0 and A - B - )since the complements are infinitive. The authors suggest to re-define the exterior of spa- tial object by replacing the complement with its Voronoi region. A new Voronoi-based 9-in- tersection (VNI) is proposed and used for formalizing topological relations between spatial objects. By improving the 9-interscetion model, it is now possible to distinguish disjoint rela- tions and to deal with objects with holes. Also it is possible to compute the exterior-based in- tersections and manipulate spatial relations with the VNI.
文摘Five lengthy periods involving multiple phases of cordierite and andalusite growth were revealed by detailed studies of foliation inflection/intersection axes （FIA） preserved in porphyroblasts in schists from the Arkansas River region in Colorado, USA. The regionally consistent character of the succession of five different FIA trends enabled the relative timing of each FIA with respect to the next to be determined. The FIA succession from first to last is： FIA 1 trending W-E, FIA 2 trending SSW- NNE, FIA 3 trending NNW-SSE, FIA 4 trending NW-SE and FIA 5 trending SW-NE. For four of the FIA sets, samples were found containing monazite grains preserved as inclusions. These were dated on an electron microprobe. The ages obtained concur exactly with the FIA succession, with FIA 1 at 1506±15 Ma, FIA 2 at 1467±23 Ma, FIA 3 at 1425±18 Ma, FIA 4 not dated and FIA 5 at 1366±20 Ma. These ages are directly reflected in a succession of plutons in the surrounding region dated by other isotopic approaches, suggesting that deformation, metamorphism and pluton emplacement occurred together episodically, but effectively continuously, for some 140 Ma.
