Transportation Network Path And Close Neighbor Of Choice

Short path query and KNN query have been paid more and more attention.In the database research community, the initial interest in short path query is to compute the shortest distance to save the time.Recently,this problem has captured the attention of database researchers again,due to the fast growing graph data,such as large scale social networks, and biological networks. KNN query is a classical problem that has been extensively studied due to its many important applications, such as spatial databases, pattern recognition, DNA sequencing. Database researchers pay attention to KNN query.Path queries such as finding the shortest path in travel time from my hotel to the airport" are heavily used in many applications of road networks. In this paper, we study the generalized form of this query, called Arrive Time-dependent shortest-path (ATDSP) problem: to ?nd the optimal path (with the minimum travel time) from a source to a destination, based on a time-dependent graph, when arrive time (arrive the destiantion) is selected from a user-given arrive-time interval. Experiments show that our algorithm is efficiency and practicality.KNN queries such as finding nearest resterant from the current place are heavily used in our daily lifes. In this paper, we proposed a related problem called QKNN (KNN with conditions): find k nearest neighbors, which meet some conditions. We divide conditions into categories. Based on some interesting properties of the problem, we come up with an efficient algorithm called Z-KNN. Experiments show that our algorithm is efficiency and practicality.