Loading...
11 results
Search Results
Now showing 1 - 10 of 11
- MyTv: sistema personalizado de televisãoPublication . Ferreira, João; Jesus, Rui; Abrantes, ArnaldoAbordam-se os requisitos gerais de um sistema personalizado de televisão, no qual os utilizadores registados seriam alertados de programas interessantes, existentes no fluxo de programas, disponíveis num sistema de televisão por cabo.
- Terceira geração de sistemas de pesquisa de informaçãoPublication . Ferreira, João; Jesus, Rui; Abrantes, ArnaldoPretende-se discutir e fundamentar um conjunto de ideias necessárias para o desenvolvimento de sistemas de pesquisa com o objectivo de melhorar o desempenho dos mesmos. Assuntos como a personalização, perfil, interfaces de ajuda, uso de sistemas de classificação e contextualização da pesquisa são analisados e discutidos numa abordagem que permite integrar de uma forma unificada as suas potencialidades.
- Driving simulator for performance monitoring with physiological sensorsPublication . Raimundo, Diogo; Lourenço, André; Abrantes, ArnaldoThis paper describes a driving monitoring system based on a car driving simulator, specifically built for this project, using inexpensive off-the-shelf game technology (software and hardware). The project aims to study the effect of drowsiness (caused by fatigue, alcohol consumption, etc.) in driving performance and how it can be detected in advance in order to mitigate accidents. To achieve this, the system is continuously monitoring driver's physiological signals (e.g., heart rate) as well as her/his driving behavior. Electrocardiography (ECG) signal plays a central role in this project, since a feature derived from it - the HRV (Heart Rate Variability), more concretely its power spectral distribution - is used to continuously estimate the driver's degree of awareness and therefore for generation of alarms. A preliminary evaluation of the proposed system is discussed through the presentation of some experimental results.
- Methods for automatic and assisted image annotationPublication . Jesus, Rui; Abrantes, Arnaldo; Correia, NunoPersonal memories composed of digital pictures are very popular at the moment. To retrieve these media items annotation is required. During the last years, several approaches have been proposed in order to overcome the image annotation problem. This paper presents our proposals to address this problem. Automatic and semi-automatic learning methods for semantic concepts are presented. The automatic method is based on semantic concepts estimated using visual content, context metadata and audio information. The semi-automatic method is based on results provided by a computer game. The paper describes our proposals and presents their evaluations.
- Sistema para pesquisa de imagens com retroacção de relevânciaPublication . Jesus, Rui; Abrantes, Arnaldo; Marques, Jorge S.Recentemente, a retroacção de relevância tem sido utilizada para melhorar o desempenho dos sistemas de pesquisa em base de dados de imagens. Este artigo apresenta um método de Retroacção de Relevância baseado no classificador de Mínimos Quadrados Regularizado e numa técnica de selecção de imagens que permite aumentar a capacidade de aprendizagem do método. São apresentados resultados de testes experimentais.
- AUTOMOTIVE: a case study on AUTOmatic multiMOdal drowsiness detecTIon for smart VEhiclesPublication . Esteves, Telma; Pinto, João Ribeiro; Ferreira, Pedro M.; Costa, Pedro Amaro; Rodrigues, Lourenço Abrunhosa; Antunes, Inês; Lopes, Gabriel; gamito, pedro; Abrantes, Arnaldo; Jorge, Pedro; Lourenço, André; Sequeira, Ana F.; Cardoso, Jaime S.; Rebelo, AnaAs technology and artificial intelligence conquer a place under the spotlight in the automotive world, driver drowsiness monitoring systems have sparked much interest as a way to increase safety and avoid sleepiness-related accidents. Such technologies, however, stumble upon the observation that each driver presents a distinct set of behavioral and physiological manifestations of drowsiness, thus rendering its objective assessment a non-trivial process. The AUTOMOTIVE project studied the application of signal processing and machine learning techniques for driver-specific drowsiness detection in smart vehicles, enabled by immersive driving simulators. More broadly, comprehensive research on biometrics using the electrocardiogram (ECG) and face enables the continuous learning of subject-specific models of drowsiness for more efficient monitoring. This paper aims to offer a holistic but comprehensive view of the research and development work conducted for the AUTOMOTIVE project across the various addressed topics and how it ultimately brings us closer to the target of improved driver drowsiness monitoring.
- Automatic vehicle detection and classificationPublication . Ferreira, Pedro Miguel; Marques, Gonçalo; Jorge, Pedro; Abrantes, Arnaldo; Amador, AntónioThis paper presents a proposal for an automatic vehicle detection and classification (AVDC) system. The proposed AVDC should classify vehicles accordingly to the Portuguese legislation (vehicle height over the first axel and number of axels), and should also support profile based classification. The AVDC should also fulfill the needs of the Portuguese motorway operator, Brisa. For the classification based on the profile we propose:he use of Eigenprofiles, a technique based on Principal Components Analysis. The system should also support multi-lane free flow for future integration in this kind of environments.
- Tracking with Bayesian networks: extension to arbitrary topologiesPublication . Jorge, Pedro; Abrantes, Arnaldo; Marques, Jorge S.It was recently proposed an object tracking method, which is able to deal with object occlusions and group tracking, using Bayesian networks. The Bayesian network (BN) tracker has shown promising results in difficult situations but its architecture is limited to a maximum of 2 parents/2 children per node, in order to avoid the combinatorial explosion and difficult network generation procedures from the video signal. This paper addresses the major limitation of the BN tracker and presents a method to generalize the tracker to cope with arbitrary topologies, allowing the tracker to operate in more complex scenes.
- Automatic tracking of multiple pedestrians with group formation and occlusionsPublication . Jorge, Pedro; Abrantes, Arnaldo; Marques, Jorge S.This work addresses the problem of automatic track ing of pedestrians observed by a fixed camera in out door scenes. Tracking isolated pedestrians is not a difficult task. The challenge arises when the track ing system has to deal with temporary occlusions and groups of pedestrians. In both cases it is not possi ble to track each pedestrian during the whole video sequence. However, the system should be able to rec ognize each pedestrian as soon as he/she becomes vis ible and isolated from the group. This paper presents methods to tackle these difficulties. The proposed sys tem is based on a hierarchical approach which allows the application of the same methods for tracking iso lated pedestrians and groups.
- Interoperability among its systems with Its-Ibus frameworkPublication . F. G. Osório, A. Luís; Barata, Manuel; Gonçalves, Carlos; Araújo, P.; Abrantes, Arnaldo; Jorge, Pedro; Gomes, J. Sales; Jacquet, G.; Amador, A.This paper presents and discusses the extended Via-Verde business model from the point of view of the underlying requirements for the virtual business processes. The extension of Via-Verde concept to other services beyond the motorway toll collection has increased the number of independent companies involved. The complex networked scenario resulted on a proposal of an intelligent transport system — interoperability bus (ITS-IBus) (Gomes et. al. 2003) (Osorio, et. al. 2003-a) aiming to promote a generalized interoperability among heterogeneous (multi-vendor) technological subsystems. The ITS-IBus initiative has been developing since then, a reference implementation of a peer-to-peer service based framework with pluggable feature and a set of common agreed interfaces for coupling different technological systems. An important objective is to increase the quality of the offered services by establishing a flexible execution and coordination framework for the collaborative distributed business processes.