Study on computer perception of topological symmetry

A new algorithm for computer perception of topological symmetry is proposed. A node library containing various kinds of nodes is built, and the index number of the library is used as initial atom class identifier (CI) to discriminate the different types of non-hydrogen atoms. The path index (PI) and ringindex (RI) are calculated from the CI, and the global topological enviroment is defined as the sum of PIs and RIs. The topological symmetry can be detected by the iterative calculation of the global topological enviroment.

ALGORITHM FOR COMPUTER PERCEPTION OF TOPOLOGICAL SYMMETRY

For the exhaustive and irredundant generation of candidate structures in ESESOC (Expert System for the Elucidation of the Structures of Organic Compounds), a new algorithm for computer perception of topological equivalence classes of the nodes (non-hydrog

空间关系类别的形成与计算

Spatial categorization and computation were studied systematically and sequentially in the dissertation, in which, category learning paradigm was transferred to spatial domain. Four parts were developed in our study, in which, the former two parts investigated the mechanism of spatial categorization, and the latter two parts explored two applied issues. Spatial category formation was investigated by two aspects in distance and angle respectively in research one. The results showed that subjects can make accurate judgment and rating for corresponding spatial categorical prototypes and boundaries. In the second research, the formation of spatial relationship categorization was examined through two factors of number of categories and different spatial configurations. The results were repeated in this part, and also, different influences of reference of frame were found in the process of spatial categorization. In the third research, the influences of spatial categorization on spatial localization were found, that in subject could make different location judgment with new acquired spatial categories. Spatial position distribution has no effect on spatial localization on the other hand. The result that reference objects have significant influences on applicability of spatial relationship was found in research four. Our Bayesian hierarchical model could be applied in simulation and prediction of perception of “above” spatial relationship. Theoretical significance and applied importance were discussed in detail.