Query understanding is an important component of web search, like document understanding, query document matching, ranking, and user understanding. The goal of query understanding is to predict the user’s search intent from the given query. Needless to say, search log mining and statistical learning are fundamental technologies to address the task of query understanding. In this talk, I will fi...

Segment databases store N non-crossing but possibly touching segments in secondary storage. EEcient data structures have been proposed to determine all segments intersecting a vertical line (stabbing queries). In this paper, we consider a more general type of query for segment databases, determining intersections with respect to a generalized segment (a line, a ray, a segment) with a xed angula...

Through their interaction with search engines, users provide implicit feedback that can be used to extract useful knowledge and improve the quality of the search process. This feedback is encoded in the form of a query log that consists of a sequence of search actions, which contain information about submitted queries, documents viewed, and documents clicked by the users. In this paper, we prop...

Since 2009 LogCLEF has been the initiative within the CrossLanguage Evaluation Forum which aims at stimulating research on user behavior in multilingual environments and promote standard evaluation collections of log data. During these editions of LogCLEF, different collections of log dataset were distributed to the participants together with manually annotated query records to be used as a tra...

In this paper, we present a survey of important work done on automatic query expansion. Automatic query expansion is the process of automatically supplementing additional terms or phrases to the original query and is considered an extremely promising technique to improve the retrieval effectiveness. In this survey, we discussed a large number of recent approaches to automatic query expansion th...

Given a vertex-labeled graph, each vertex v is attached with a label from a set of labels. The vertex-label query desires the length of the shortest path from the given vertex to the set of vertices with the given label. We show how to construct an oracle if the given graph is planar, such that O( 1 ǫ n log n) storing space is needed, and any vertexlabel query could be answered in O( 1 ǫ log n ...

Given a planar environment consisting of n disjoint axisaligned rectangles, we want to query on any two points and find whether there is a north-east monotone path between them. We present preprocessing and query algorithms which translate the geometric problem into a tree traversal problem and present a corresponding tree structure that gives usO(n log n) construction time, O(n) space, and O(l...

Distance oracles are data structures that provide fast (possibly approximate) answers to shortestpath and distance queries in graphs. The tradeoff between the space requirements and the query time of distance oracles is of particular interest and the main focus of this paper. In FOCS‘01, Thorup introduced approximate distance oracles for planar graphs. He proved that, for any > 0 and for any pl...

In this paper, we have developed a fully-dynamic algorithm for maintaining cardinality of maximum-matching in a tree using the construction of top-trees. The time complexities are as follows: 1. Initialization Time: O(n(log(n))) to build the Top-tree. 2. Update Time: O(log(n)) 3. Query Time: O(1) to query the cardinality of maximum-matching and O(log(n)) to find if a particular edge is matched.

We present output sensitive techniques for the generalized reporting versions of the planar range maxima problem and the planar range convex hull problem. Our solutions are in the pointer machine model, for orthogonal range queries on a static point set. We solve the planar range maxima problem for two-sided, three-sided and four-sided queries. We achieve a query time of O(log n+c) using O(n) s...