We consider the planar convex hull range query problem. Let P be a set of points in the plane. We preprocess these points into a data structure such that given an orthogonal range query, we can report the convex hull of the points in the range in O(log n + h) time, where h is the size of the output. The data structure uses O(n log n) space. This improves the previous bound of O(log n+h) time an...

Many queries in web search are ambiguous or multifaceted. Identifying the major senses or facets of queries is very important for web search. In this paper, we represent the major senses or facets of queries as subtopics and refer to indentifying senses or facets of queries as query subtopic mining, where query subtopic are represented as a number of clusters of queries. Then the challenges of ...

We consider the following problem: Given an unsorted array of n elements, and a sequence of intervals in the array, compute the median in each of the subarrays defined by the intervals. We describe a simple algorithm which needs O(n log k + k logn) time to answer k such median queries. This improves previous algorithms by a logarithmic factor and matches a comparison lower bound for k = O(n). T...

The human interaction through the web generates both implicit and explicit knowledge. An example of an implicit contribution is searching, as people contribute with their knowledge by clicking on retrieved documents. When this information is available, an important and interesting challenge is to extract relations from query logs, and, in particular, semantic relations between queries and their...

In this paper we deal with the problem of automatic detection of query intent in search engines. We studied features that have shown good performance in the state-of-theart, combined with novel features extracted from click-through data. We show that the combination of these features gives good precision results. In a second stage, four textbased classifiers were studied to test the usefulness ...

Modern search engines have been moving away from very simplistic interfaces that aimed at satisfying a user’s need with a single-shot query. Interactive features such as query suggestions and faceted search are now integral parts of Web search engines. Generating good query modification suggestions or alternative queries to assist a searcher remains however a challenging issue. Query log analys...

Web search users usually submit short and ambiguous queries to specify their requirement. In order to improve performance of short and ambiguous queries, query expansion is used. Query expansion is as an effective way to improve the performance of information retrieval systems by adding relevant terms to the original query. After using search engine lots of data get accumulated, from which quer...

We consider the fundamental problem of 2-D dynamic orthogonal range reporting for 2and 3-sided queries in the standard word RAM model. While many previous dynamic data structures use O(log n/ log log n) update time, we achieve faster O(log n) and O(log n) update times for 2and 3-sided queries, respectively. Our data structures have optimalO(log n/ log log n) query time. Only Mortensen [13] had ...

We analyse the statistical behavior of query-associated quantities in query-logs, namely, the sum and mean of IDF of query terms, otherwise known as query specificity and query mean specificity. We narrow down the possibilities for modeling their distributions to gamma, log-normal, or log-logistic, depending on query length and on whether the sum or the mean is considered. The results have appl...

We consider the following problem: Preprocess a set S of n axis-parallel boxes in R so that given a query of an axis-parallel box in R, the pairs of boxes of S whose intersection intersects the query box can be reported efficiently. For the case that d = 2, we present a data structure of size O(n log n) supporting O(log n+ k) query time, where k is the size of the output. This improves the prev...