A k-query locally decodable code (LDC) C : Σn → ΓN encodes each message x into a codeword C(x) such that each symbol of x can be probabilistically recovered by querying only k coordinates of C(x), even after a constant fraction of the coordinates have been corrupted. Yekhanin (2008) constructed a 3-query LDC of subexponential length, N = exp(exp(O(log n/ log log n))), under the assumption that ...

A hierarchical decomposition of a simple polygon is introduced. The hierarchy has depth O(log n), linear size, and its regions have at most three neighbors. Using this hierarchy, circular ray shooting queries in a simple polygon can be answered in O(log n) query time and O(n log n) space. If the radius of the circle is xed, the query time can be improved to O(log n) and the space to O(n).

Text summarisation is the process of distilling the most important information from a source to produce an abridged version for a particular user or task. This demo presents the use of profile-based summarisation to provide contextualisation and interactive support for site search and enterprise search. We employ log analysis to acquire continuously updated profiles to provide profile-based sum...

Cuckoo hashing is a powerful primitive that enables storing items using small space with efficient querying. At high level, cuckoo maps n into b entries at most $$\ell $$ such each item placed one of k randomly chosen entries. Additionally, there an overflow stash can store s items. Many cryptographic primitives rely upon to privately embed and query data where it integral ensure failure probab...

In this paper we describe compressed indexes that support pattern matching queries for strings with wildcards. For a constant size alphabet our data structure uses O(n log n) bits for any ε > 0 and reports all occ occurrences of a wildcard string in O(m + σ · μ(n) + occ) time, where μ(n) = o(log log logn), σ is the alphabet size, m is the number of alphabet symbols and g is the number of wildca...

This paper addresses the problem of finding the nearest neighbor (or one of the R-nearest neighbors) of a query object q in a database of n objects, when we can only use a comparison oracle. The comparison oracle, given two reference objects and a query object, returns the reference object most similar to the query object. The main problem we study is how to search the database for the nearest ...

In our TREC-8 interactive experiment, we compared the effectiveness of a user-defined passage feedback system with a conventional document feedback system. The passage feedback system (pf) employed user-defined passages to formulate a feedback query, while the document feedback (df) system utilized document-level relevance judgments. The df system employed the adaptive linear model for retrieva...

In this paper, we define the Range LCP problem as follows. Preprocess a string S, of length n, to enable efficient solutions of the following query: Given [i, j], 0 < i ≤ j ≤ n, compute max`,k∈{i,...,j} LCP (S`, Sk), where LCP (S`, Sk) is the length of the longest common prefix of the suffixes of S starting at locations ` and k. This is a natural generalization of the classical LCP problem. Sur...

Let S be a connected planar polygonal subdivision with n edges that we want to preprocess for point-location queries, and where we are given the probability γi that the query point lies in a polygon Pi of S. We show how to preprocess S such that the query time for a point p ∈ Pi depends on γi and, in addition, on the distance from p to the boundary of Pi—the further away from the boundary, the ...