INESC-ID

About: INESC-ID is a nonprofit organization based out in Lisbon, Portugal. It is known for research contribution in the topics: Field-programmable gate array & Control theory. The organization has 932 authors who have published 2618 publications receiving 37658 citations.

Design and Evaluation of eTIMIP - an Overlay Micro-Mobility Architecture based on TIMIP

Abstract: All the proposed IP mobility protocols assume that the mobile nodes always have a mobility-aware IP stack. On the other hand, efficient micro-mobility solutions entail specific topologies and mobile-aware routers, requiring major changes in the existing infra-structures. Major advantages are foreseen if mobility can be supported using the existing legacy infra-structure, on both client and network sides, allowing a smooth upgrade process. This paper describes such kind of solution, by proposing an efficient terminal independent mobility architecture (eTIMIP - enhanced TIMIP) which is compliant with the macro-mobility standard and which uses an overlay network to provide transparent micro-mobility support in all existing networks, using an enhanced version of the previously proposed TIMIP protocol. Simulation results have revealed the efficiency, the transparency and the reliability of the proposed architecture through comparison to other proposals.

Multiplierless Design of Folded DSP Blocks

Abstract: This article addresses the problem of minimizing the implementation cost of the time-multiplexed constant multiplication (TMCM) operation that realizes the multiplication of an input variable by a single constant selected from a set of multiple constants at a time. It presents an efficient algorithm, called orpheus, that finds a multiplierless TMCM design by sharing logic operators, namely adders, subtractors, adders/subtractors, and multiplexors (MUXes). Moreover, this article introduces folded design architectures for the digital signal processing (DSP) blocks, such as finite impulse response (FIR) filters and linear DSP transforms, and describes how these folded DSP blocks can be efficiently realized using TMCM operations optimized by orpheus. Experimental results indicate that orpheus can find better solutions than existing TMCM algorithms, yielding TMCM designs requiring less area. They also show that the folded architectures lead to alternative designs with significantly less area, but incurring an increase in latency and energy consumption, compared to the parallel architecture.

The fuzzy boundaries of operator verb and support verb constructions with dar ``give'' and ter ``have'' in Brazilian Portuguese

Abstract: This paper describes the fuzzy boundaries between support verb constructions (SVC) with ter “have” and dar “give” and causative operator verb (VopC) constructions involving these same verbs, in Brazilian Portuguese (BP), which form a complex set of relations: (i) both verbs are the support verb of the same noun (SVC); (ii) dar is the standard (active-like) SVC while ter is a converse (passive-like) SVC; and (iii) dar is a VopC, operating on a ter SVC. In this paper we have systematically studied these complex relations involving SVC and VopC for BP, which constitute a challenge to Natural Language Processing (NLP) systems, and have been often ignored in related work. The paper proposes a lexically-based strategy to implement SVC in a fully-fledged, rule-based parsing system, yielding an adequate semantic structure of the events (predicates) denoted by predicative nouns in SVC.

Vocabulary selection for a broadcast news transcription system using a morpho-syntactic approach.

Abstract: Although the vocabularies of ASR systems are designed to achieve high coverage for the expected domain, out-ofvocabulary (OOV) words cannot be avoided. Particularly, for daily and real-time transcription of Broadcast News (BN) data in highly inflected languages, the rapid vocabulary growth leads to high OOV word rates. To overcome this problem, we present a new morpho-syntatic approach to dynamically select the target vocabulary for this particular domain by trading off between the OOV word rate and vocabulary size. We evaluate this approach against the common selection strategy based on word frequency. Experiments have been carried out for a European Portuguese BN transcription system. Results computed on seven news shows, yields a relative reduction of 37.8% in OOV word rate against the baseline system and 5.5% when compared with the word frequency common approach.

Automatic vs. manual topic segmentation and indexation in broadcast news

Abstract: This paper describes the latest progress in our work on Broadcast News for European Portuguese. The central modules of our media watch system that matches the topic of each news story against the user preferences registered in the system are: audio pre-processing, speech recognition and topic segmentation and indexation. The main focus of the paper is on the impact of the errors made by the earlier modules in the last ones. This impact is in our opinion an essential diagnostic tool for the improvement of the overall pipeline system.