This article describes GALATEAS LangLog, a system performing Search Log Analysis. LangLog illustrates how NLP technologies can be a powerful support tool for market research even when the source of information is a collection of queries each one consisting of few words. We push the standard Search Log Analysis forward taking into account the semantics of the queries. The main innovation of Lang...

We present linear-space sub-logarithmic algorithms for handling the 3-dimensional dominance reporting and the 2-dimensional dominance counting problems. Under the RAM model as described in [M. L. Fredman and D. E. Willard. “Surpassing the information theoretic bound with fusion trees”, Journal of Computer and System Sciences, 47:424– 436, 1993], our algorithms achieve O(log n/ log log n + f) qu...

Let P be a set of n points in the plane. The k-nearest neighbor (k-NN) query problem is to preprocess P into a data structure that quickly reports k closest points in P for a query point q. This paper addresses a generalization of the k-NN query problem to a query set Q of points, namely, the group nearest neighbor problem, in the L1 plane. More precisely, a query is assigned with a set Q of at...

In this paper, new results for two fundamental problems in the field of computational geometry are presented: orthogonal point enclosure query (OPEQ) in R and point location in orthogonal subdivisions in R. All the results are in the pointer machine model of computation. (1) In an orthogonal point enclosure query, a set S of n axes-parallel rectangles in R is to be preprocessed, so that given a...

Leveraging query logs benefits the users analyzing large data warehouses with OLAP queries. But so far nothing exists to allow the user to have concise and usable representations of what is in the log. In this article, we present a framework for summarizing and querying OLAP query logs. The basic idea is that a query summarizes another query and that a log, which is a sequence of queries, summa...