Voronoi Partition to Support Data Search in Uncertain Database with k-Bound Filtering

Abstract

With the development of mobile technology, one of its main functions is to have mobile navigation capabilities, this is one of the Location-Based Services (LBS). Mobile navigation is designed as a mobile device to be able to monitor access objects from users. Because of the mobile characteristic, the impact on the points of objects to be found always occur a not certain change. Efficient query processing is needed on a set of mobile data due to the movement of users. This movement has an impact on searching in an uncertain database. For this uncertain database, the important query method is Probabilistic k-Nearest Neighbor query (PkNN), which calculates the probability of the set of k objects to be closest to the given query point. Several studies have been conducted at this time in order to contribute to the search results in a mobile database and uncertain with the support of certain algorithms to produce better performance. In this study, we propose a method called voronoi partitioning to support searching in uncertain database (Partition threshold k Aggregate Nearest Neighbor query method-Partition_PANN). In designing the partition of the voronoi region, it starts by using voronoi local networks to calculate query answers for small areas around the request point. A query point that meets the threshold used as a value as a set of threshold queries. So, all of the query points that meet the thresholds are the basis for forming local network voronoi partitions. Thus, this method does not require preliminary calculations also evaluation of distances at each intersection. The purpose of this research is to improve the performance of queries in an uncertain database by making the aggregate process and trimming the probability value as one phase of the search algorithm. In the first stage, objects which not able to form the answers are filtered by calculating the minimum closed circle from the dataset of query which prepared for the trimming phase. The second step called probabilistic candidate selection, its cut significant set of candidates for inspected as the aggregate function of the nearest neighbor’s demand. The remaining set is sent for verification which obtains possible answers at the lower and upper limits so that candidates whose probabilities are not less than the user-specified threshold are saved in the result set and returned to the user. We also examine the efficient data structures spatially which support this method. Our solution can be applied to uncertain data with an ever-changing probability density function.