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Moving object databases (MOD) have gained much interest in recent years due to the advances in mobile communications and positioning technologies. Study of MOD can reveal useful information (e.g., traffic patterns and congestion trends) that can be used in applications for the common benefit. In order to mine and/or analyze the data, MOD must be published,(More)
We study the query answering using views (QAV) problem for tree pattern queries. Given a query and a view, the QAV problem is traditionally formulated in two ways: (i) find an equivalent rewriting of the query using only the view, or (ii) find a maximal contained rewriting using only the view. The former is appropriate for classical query optimization and(More)
XPath and XQuery (which includes XPath as a sublanguage) are the major query languages for XML. An important issue arising in efficient evaluation of queries expressed in these languages is satisfiability, i.e., whether there exists a database, consistent with the schema if one is available, on which the query has a non-empty answer. Our experience shows(More)
Spurred by developments such as cloud computing, there has been considerable recent interest in the paradigm of data mining-as-service. A company (data owner) lacking in expertise or computational resources can outsource its mining needs to a third party service provider (server). However, both the items and the association rules of the outsourced database(More)
Motivated by the "database-as-service" paradigm wherein data owned by a client is hosted on a third-party server, there is significant interest in secure query evaluation over encrypted databases. We consider this problem for XML databases. We consider an attack model where the attacker may possess exact knowledge about the domain values and their(More)
To support privacy-aware management of data in social spaces, the user personal data needs to be stored at each user device, and shared only with a trusted subset of other users. To date, social spaces only have fairly limited access control capabilities, that do not protect the possibly sensitive data of the users. In this demonstration, we showcase our(More)
Recommender systems are used to predict user preferences for products or services. In order to seek better prediction techniques, data owners of recommender systems such as Netflix sometimes make their customers' reviews available to the public, which raises serious privacy concerns. With only a small amount of knowledge about individuals and their ratings(More)
Deterministic Approach • Goal: verify each tuple has been assigned to the nearest centroid • Brute-force approach: for each tuple, compute its distance to all cluster centroids. • Our approach: for each tuple, compute its distance to all of its Voronoi centroid neighbors. • Service provider (server)-provides storage and computational power as the service. •(More)
The annual ACM SIGMOD conference is a leading international forum for database researchers, practitioners, developers, and users to explore cutting-edge ideas and results, and to exchange techniques, tools, and experiences. We invite the submission of original research contributions relating to all aspects of data management defined broadly, and(More)