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In this paper we propose an algorithm for answering reverse nearest neighbor (RNN) queries, a problem formulated only recently. This class of queries is strongly related to that of nearest neighbor (NN) queries, although the two are not necessarily complementary. Unlike nearest neighbor queries, RNN queries nd the set of database points that have the query(More)
In this paper we introduce the notion of constrained nearest neighbor queries (CNN) and propose a series of methods to answer them. This class of queries can be thought of as nearest neighbor queries with range constraints. Although both nearest neighbor and range queries have been analyzed extensively in previous literature, the implications of constrained(More)
In this paper, we explore the use of the simple variants of broadcast protocols for managing replicated databases. In particular, we start with the simplest broadcast primitive, the reliable broadcast protocol, and show how it can be used to ensure correct transaction execution. The protocol is simple, and has several advantages, including prevention of(More)
We address the problem of preserving privacy in streams, which has received surprisingly limited attention. For static data, a well-studied and widely used approach is based on random perturbation of the data values. However, streams pose additional challenges. First, analysis of the data has to be performed incrementally, using limited processing time and(More)
The primary goal of the Midas project is to build a system that enables easy and scalable integration of unstructured and semi-structured information present across multiple data sources. As a first step in this direction, we have built a system that extracts and integrates information from regulatory filings submitted to the U.S. Securities and Exchange(More)
Business process integration and monitoring provides an invaluable means for an enterprise to adapt to changing conditions. However, developing such applications using traditional methods is challenging because of the intrinsic complexity of integrating large-scale business processes and existing applications. Model Driven Developmente (MDDe) is an approach(More)
Increasing popularity of XML in recent years has generated much interest in query processing over graph-structured data. To support efficient evaluation of path expressions, many structural indexes have been proposed. The most popular ones are the 1-index, based on the notion of graph bisimilarity, and the recently proposed A(<i>k</i>)-index, based on the(More)
We present Midas, a system that uses complex data processing to extract and aggregate facts from a large collection of structured and unstructured documents into a set of unified, clean entities and relationships. Midas focuses on data for financial companies and is based on periodic filings with the U.S. Securities and Exchange Commission (SEC) and Federal(More)