We consider the problem of on-line exact string matching of a pattern in a set of highly similar sequences. This can be useful in cases where indexing the sequences is not feasible. We present a preliminary study by restricting the problem for a specific case where we adapt the classical Morris-Pratt algorithm to consider borders with errors. We give an original algorithm for computing borders ...

We develop new algorithmic and cryptographic techniques for authenticating the results of queries over databases that are outsourced to an untrusted responder. We depart from previous approaches by considering super-efficient answer verification, where answers to queries are validated in time asymptotically less that the time spent to produce them and using lightweight cryptographic operations....

A writer independent handwriting recognition system must be able to recognize a wide variety of handwriting styles, while attempting to obtain a high degree of accuracy when recognizing data from any one of those styles. As the number of writing styles increases, so does the variability of the data’s distribution. We then have an optimization problem: how to best model the data, while keeping t...

We consider the problem of multi-track string matching. The task is to find the occurrences of a pattern across parallel strings. Given an alphabet Σ of natural numbers and a set S over Σ of h strings si = s1 · · · s i n for i = 1, . . . , h, a pattern p = p1 · · · pm has such an occurrence at position j of S if p1 = s i1 j , p2 = s i2 j+1, . . . , pm = s im j+m−1 holds for i1, . . . , im ∈ {1,...

Searching online is one of the most powerful resources today’s students have for accessing information. Searching in groups is a daily practice across multiple contexts; however, the tools we use for searching online do not enable collaborative practices and traditional search models consider a single user navigating online in solitary. This paper presents a three level conceptual model, called...

A successful technique to search large textual databases allowing errors relies on an online search in the vocabulary of the text. To reduce the time of that on-line search, we index the vocabulary as a metric space. We show that with reasonable space overhead we can improve by a factor of two over the fastest online algorithms , when the tolerated error level is low (which is reasonable in tex...

We introduce a spatial index to support the fast retrieval of large neighborhoods of points on a polygonal mesh. Our spatial index can be computed efficiently off-line, introducing a negligible overhead over a standard indexed data structure. In retrieving neighborhoods of points on-line, we achieve a speed-up of about one order of magnitude with respect to standard topological traversal, while...

of Results We investigate the maximal number of character comparisons made by a linear-time string matching algorithm, given a text of length n and a pattern of length m over a general alphabet. We denote it by c(n,m) or approximate it by (1 + C)n, where C is a universal constant. We add the subscript “on-line” when we restrict attention to on-line algorithms and the superscript “1” when we con...