4 results about "R-tree" patented technology

The application relates to the field of privacy protection query schemes, in particular to an indoor multi-user personalized spatial keyword privacy query method based on a GIS enhanced index tree. In view of the demand of multi-user spatial keyword privacy query in an indoor environment, a GISEnhancedIndexTree index structure is constructed by fusing Hilbert coding, an R tree, an encrypted Bloom filter and an EASPE encrypted vector, and spatial and text information of indoor objects are encrypted and indexed. During query, a user request is encrypted and processed into a trapdoor, a server performs spatial, floor and keyword pre-filtering in the index tree according to the trapdoor, calculates the similarity of encrypted vectors by means of EASPE, and returns the encrypted result to the user after threshold filtering, score aggregation and sorting. Meanwhile, a comprehensive position vector construction method and a privacy protection coordinate conversion method based on a local coordinate system are designed to guarantee the privacy safety of the whole data flow. The method can effectively protect the privacy of users and improve the efficiency and accuracy of indoor multi-user personalized spatial keyword query.

The application discloses a kind of based on GiST spatial index multi-resolution fragmentation DEM database construction method, comprising: S1, with the resolution of fragmentation DEM image tile as hierarchical division standard;S2, existing DEM image tile is hierarchically divided according to S1 hierarchical division standard, to minimum outer rectangle as unit independent storage;S3, based on DEM image tile, the hierarchical structure rule of R tree is used to establish parent-child node relationship, and the initial R tree multi-resolution skeleton is constructed;S4, on the basis of initial R tree multi-resolution skeleton, uniform different hierarchical spatial relationship description rule is formulated, and according to the rule, the spatial correlation between DEM image tile is described, and the preliminary establishment of multi-resolution DEM database based on GiST spatial index is completed;S5, the DEM image tile to be stored is stored into database, and the database is improved.The application improves the performance of DEM data storage.

The invention discloses a query method and system based on a trajectory index structure, and the method comprises the steps: S1, constructing a probabilistic maneuvering R tree: S11, receiving a to-be-inserted dynamic object, and modeling the motion uncertainty of the to-be-inserted dynamic object into a PMBR which is composed of a plurality of maneuvering unit groups; s12, inserting an object into a leaf node which enables the internal motion confusion degree of the node to be increased to the minimum, if the inserted node overflows, executing a node splitting method based on a future interaction score, and selecting a division scheme which enables the interaction possibility of the two split nodes in a future time window to be minimum; s13, inserting an object at a leaf node; s14, splitting the nodes; and S15, updating the PMBR of the ancestor node upwards. And S2, receiving a query request, and returning a query result. According to the method, the pruning efficiency of predictive query is remarkably improved. A flexible motion model is applied, and a pruning strategy and accurate calculation are combined, so that the query performance is greatly improved while the accuracy is ensured.

The application discloses a chip layout link tracking method based on a scan line and an R tree, and belongs to the technical field of calculation, estimation or counting. The method comprises the following steps: analyzing an input layout file, constructing an event queue for a read graph, storing events into an R tree and traversing the R tree by using a scan line, and outputting a required graph set. The above method can effectively realize efficient processing of large-scale layout data and rapid extraction of multilayer links.