Efficient K-nearest neighbor search in time-dependent spatial networks
First Claim
1. A computer-readable, non-transitory medium encoding a computer program product operable to cause data processing apparatus of a location-based, geographical points of interest searching system, to perform operations comprising:
- partitioning a time-dependent spatial network into cells around the points of interest, the points of interest being associated with locations in the time-dependent spatial network, and the cells comprising a tight cell and a loose cell for each of the points of interest; and
finding, in response to a query submitted to the searching system, the query having an associated location in the time-dependent spatial network, a specified number of the points of interest that are nearest to the location, using the tight cells and the loose cells.
2 Assignments
0 Petitions
Accused Products
Abstract
The class of k Nearest Neighbor (k NN) queries in spatial networks has been studied in the literature. Existing approaches for k NN search in spatial networks assume that the weight of each edge in the spatial network is constant. However, real-world edge-weights are time-dependent and vary significantly in short durations, hence invalidating the existing solutions. The problem of k NN search in time-dependent spatial networks, where the weight of each edge is a function of time, is addressed herein. Two indexing schemes (Tight Network Index and Loose Network Index) are proposed to minimize the number of candidate nearest neighbor objects and reduce the invocation of the expensive fastest-path computation in time-dependent spatial networks. We demonstrate the efficiency of our proposed solution via experimental evaluations with real-world data-sets, including a variety of large spatial networks with real traffic-data.
50 Citations
14 Claims
-
1. A computer-readable, non-transitory medium encoding a computer program product operable to cause data processing apparatus of a location-based, geographical points of interest searching system, to perform operations comprising:
-
partitioning a time-dependent spatial network into cells around the points of interest, the points of interest being associated with locations in the time-dependent spatial network, and the cells comprising a tight cell and a loose cell for each of the points of interest; and finding, in response to a query submitted to the searching system, the query having an associated location in the time-dependent spatial network, a specified number of the points of interest that are nearest to the location, using the tight cells and the loose cells. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A system comprising:
-
a user interface device; and one or more computers operable to interact with the user interface device, the one or more computers comprising at least one processor and at least one memory device, and the one or more computers configured and arranged to perform operations comprising partitioning a network of nodes and edges into sub-networks around data objects of interest within the network, wherein each of the edges has an associated time-dependent weight, and the partitioning comprises (i) expanding one of the sub-networks starting from a corresponding one of the data objects and using a lower-bound for edge weights between nodes, and (ii) limiting the expansion of the one sub-network by expanding other sub-networks starting from remaining ones of the data objects and using an upper-bound for edge weights between nodes; and
the operations comprising finding, in response to a query having an associated location in the network, a specified number of the data objects of interest that are nearest to the location, using the sub-networks around the data objects. - View Dependent Claims (10, 11, 12, 13, 14)
-
Specification