INESC-ID

About: INESC-ID is a nonprofit organization based out in Lisbon, Portugal. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 932 authors who have published 2618 publications receiving 37658 citations.

Prosodic contex-based analysis of disfluencies.

Abstract: This work explores prosodic cues of disfluencies in a corpus of university lectures. Results show three significant (p < 0.001) trends: pitch and energy slopes are significantly different between the disfluency and the onset of fluency; those features are also relevant to disfluency type differentiation; and they do not seem to be a speakereffect. The best combination of linguistic features one can use to better predict the onset of fluency are pitch and energy resets as well as the presence of a silent pause immediately before a repair. Our results, thus, point out to a strategy of prosodic contrast rather than of parallelism. With this work we hope to contribute to the analysis of the prosodic behaviors in the production of the so called disfluencies and in the fluency repair in European Portuguese.

Evaluating web archive search systems

Abstract: The information published on the web, a representation of our collective memory, is rapidly vanishing. At least 77 web archives have been developed to cope with the web's transience problem, but despite their technology having achieved a good maturity level, the retrieval effectiveness of the search services they provide still presents unsatisfactory results. In this work, we propose an evaluation methodology for web archive search systems based on a list of requirements compiled from previous characterizations of web archives and their users. The methodology includes the design of a test collection and the selection of evaluation measures to support realistic and reproducible experiments. The test collection enabled, for the first time, to measure the effectiveness of state-of-the-art IR technology employed in web archives. Results confirm the poor quality of search results retrieved with such technology. However, we show how to combine temporal features, along with the regular topical features, to improve the search effectiveness on web archives. The test collection is available to the research community.

On deciding MUS membership with QBF

Abstract: This paper tackles the problem of deciding whether a given clause belongs to some minimally unsatisfiable subset (MUS) of a formula, where the formula is in conjunctive normal form (CNF) and unsatisfiable. Deciding MUS-membership helps the understanding of why a formula is unsatisfiable. If a clause does not belong to any MUS, then removing it will certainly not contribute to restoring the formula's consistency. Unsatisfiable formulas and consistency restoration in particular have a number of practical applications in areas such as software verification or product configuration. The MUS-membership problem is known to be in the second level of polynomial hierarchy, more precisely it is Σ2P -complete. Hence, quantified Boolean formulas (QBFs) represent a possible avenue for tackling the problem. This paper develops a number of novel QBF formulations of the MUS-membership problem and evaluates their practicality using modern off-the-shelf solvers.

Geographical routing implementation in ns3

Abstract: Simulation is an essential tool for computer networks research. In this regard, NS-3 is considered a very promising tool due to its possibility to simulate complex scenarios and integrate with real networks. This simulator was recently released to with a view to replace the popular NS-2 tool, but NS-3 still supports only a limited set of technologies.Geographical routing protocols appear to be an effective strategy for vehicular networks and many protocols of this type have been developed. Greedy Perimeter Stateless Routing is one of the most representative protocols of this kind of approach since it serves as a base for some of other protocols. In this article we describe and assess our NS-3 implementation of GPSR and the concept of location-service that is needed for such protocols.