Wendy Hui Wang

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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)
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)
Var genes encode a family of virulence factors known as PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1) which are responsible for both antigenic variation and cytoadherence of infected erythrocytes. Although these molecules play a central role in malaria pathogenesis, the mechanisms generating variant antigen diversification are poorly(More)
Recent years have witnessed pervasive use of location-aware devices such as GSM mobile phones, GPS-enabled PDAs, location sensors, and active RFID tags. The use of these devices generates a huge collection of spatio-temporal data, variously called moving object data, trajectory data, or moblity data. These data can be used for various data analysis purposes(More)
Storing and sharing databases in the cloud of computers raise serious concern of individual privacy. We consider two kinds of privacy risk: presence leakage, by which the attackers can explicitly identify individuals in (or not in) the database, and association leakage, by which the attackers can unambiguously associate individuals with sensitive(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)
BACKGROUND Current guidelines recommend that acute exacerbations of chronic obstructive pulmonary disease (COPD) be treated with systemic corticosteroids (SCs) for seven to 14 days. Intermittent SC use is cumulatively associated with adverse effects such as osteoporosis, hyperglycaemia and muscle weakness. Shorter treatment could therefore reduce the risk(More)