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  • 2019-09Relatório Acesso restrito Ver mais
  • Disruptive Future of Radar Based on All-Digital PN Signal Processing
    Publication . Ribeiro, Carlos; Ferreira Gil, João; Caldeirinha, Rafael; Reis, Joao R.; Sardo, Andre; Duarte, Luis; Leonor, Nuno
    This paper presents the first results on the design and implementation of a real-time and high resolution monostatic radar at 24 GHz, based on the sliding correlation of pseudonoise (PN) sequences. The real-time radar, with a high time resolution better than 4ns, is used for moving target identification (MTI) in the presence of highly dense clutter, under harsh environments and severe weather conditions (fog, snow and fire smoke or plume). A radar signal processing based on alldigital PN sequences is proposed, which represents a quantum leap in radar future front-end architecture. Results obtained in a controlled environment, inside an anechoic chamber, are presented and a benchmark with a commercially-of-the-shelf solution is presented. © 2019 IEEE.
    2019-09Artigo científico Acesso aberto Ver mais
  • Optimized Reference Picture Selection for Light Field Image Coding
    Publication . Monteiro, J. S. Ricardo; Nunes, J. L. Paulo; M. M. Rodrigues, Nuno; Faria, Sergio
    This paper proposes a new reference picture selection method for light field image coding using the pseudovideo sequence (PVS) format. State-of-the-art solutions to encode light field images using the PVS format rely on video coding standards to exploit the inter-view redundancy between each sub-aperture image (SAI) that composes the light field. However, the PVS scanning order is not usually considered by the video codec. The proposed solution signals the PVS scanning order to the decoder, enabling implicit optimized reference picture selection for each specific scanning order. With the proposed method each reference picture is selected by minimizing the Euclidean distance to the current SAI being encoded. Experimental results show that, for the same PVS scanning order, the proposed optimized reference picture selection codec outperforms HEVC video coding standard for light field image coding, up to 50% in terms of bitrate savings
    2019-09Atas de conferência Acesso aberto Ver mais
  • Modelling strain penetration effects in RC walls with smooth steel bars
    Publication . Caruso, Claudia; Bento, Rita; Sousa, Romain; Correia, António A.
    Reinforced-concrete (RC) dual wall–frame structures comprise an important proportion of the building stock in some European cities. However, many were constructed without seismic provisions and it is therefore important to assess their ability to withstand seismic events and to define strategies to reduce their potential vulnerability. This work focuses on the numerical simulation of the seismic behaviour of RC walls making use of fibre-based non-linear beam elements. Even though it is common to assume perfect bond between reinforcing bars and concrete, the relative bond–slip deformations between the two materials can contribute up to 40% of the total lateral deformation of columns when ribbed rebars are used and up to 90% in the case of smooth rebars. The aim of this paper is to provide a contribution towards understanding the importance of these effects in old RC walls and to provide indications regarding the use of a simplified bond–slip model.
    2019-09Artigo científico Acesso restrito Ver mais
  • Afonso Lopes Vieira e a elite universitária
    Publication . Nobre, Cristina
    As relações de Lopes Vieira com a universidade, sobretudo a de Coimbra, mas também a de Lisboa, nunca se chegam a perder — o poeta mantém a amizade com Eugénio de Castro, diretor da Faculdade de Letras; profere a conferência "Camões em Coimbra", em 2 de junho de 1915, (a convite da Associação Académica, representada por Horácio Menano), onde pela primeira vez lança a ideia de um monumento a Camões no Jardim Botânico, daquela cidade; recebe um diploma em fevereiro de 1925, assinado pelos Drs. Mendes dos Remédios, Simões Ventura e Joaquim de Carvalho em que lhe é reconhecido o "Liberalium Artium Praeceptores Conimbrigensis Universitatis Clarissimo Viro D. Dr. Affonso Lopes Vieira". O artigo analisa algumas das relações do escritor com a elite universitária do seu tempo.
    2019-09Artigo científico Acesso aberto Ver mais
  • Digital forensic artifacts of the Your Phone application in Windows 10
    Publication . Domingues, Patrício; Frade, Miguel; Andrade, Luis Miguel; Silva, João Victor
    Your Phone is a Microsoft system that comprises two applications: a smartphone app for Android 7 + smartphones and a desktop application for Windows 10/18.03+. It allows users to access their most recent smartphone-stored photos/screenshots and send/receive short message service (SMS) and multimedia messaging service (MMS) within their Your Phone-linked Windows 10 personal computers. In this paper, we analyze the digital forensic artifacts created at Windows 10 personal computers whose users have the Your Phone system installed and activated. Our results show that besides the most recent 25 photos/screenshots and the content of the last 30-day of sent/received SMS/MMS, the contact database of the linked smartphone(s) is available in a accessible SQLite3 database kept at the Windows 10 system. This way, when the linked smartphone cannot be forensically analyzed, data gathered through the Your Phone artifacts may constitute a valuable digital forensic asset. Furthermore, to explore and export the main data of the Your Phone database as well as recoverable deleted data, a set of python scripts – Your Phone Analyzer (YPA) – is presented. YPA is available wrapped within an Autopsy module to assist digital practitioners to extract the main artifacts from the Your Phone system.
    2019-09Artigo científico Acesso aberto Ver mais
  • The Fenix reborn: Occupational therapy in the first humanitarian mission in Portugal
    Publication . Roldão, Elisabete
    In Portugal, June 2017, there was a large fire, which was considered a national disaster. It led to changes in people's daily routines, affecting their occupational performance and making them vulnerable. At the time, the non-governmental organisation, Doctors of the World, implemented the first humanitarian mission in Portugal–The Hope Mission. This mission, which was made up of a nurse, a community mediator, two occupational therapists, four occupational therapy students and a clinical educator, intervened with the population of the entire affected region. Their main objective was to meet the needs of the people; involving them in significant activities, re-organising their roles and routines, re-structuring their daily lives, increasing their quality of life and their wellbeing and avoiding social isolation. Home visits, group activities and projects were implemented in partnership with community institutions. One of the projects was the (Re)Start Project. An initial assessment was made by the occupational therapists in order to plan the intervention. The project consisted of home visits (where an evaluation of the home context was made), group sessions (cognitive stimulation, motion sessions and group dynamics) and individual sessions (focusing on the performance issue and difficulties experienced by each person undertaking their daily routines). To understand the degree of satisfaction of the participants, specifically in relation to the (Re)Start project, a questionnaire was given to all who participated for more than one month. From analysis of the questionnaires, the conclusion was drawn that participants were satisfied with the activities developed in the project and found them meaningful. The presence of occupational therapy in this scenario was found to be important and made a difference. It would be useful to repeat this type of intervention at a national level, if a further humanitarian crisis occurs, especially in areas with ageing population or which are geographically isolated.
    2019-09-02Artigo científico Acesso restrito Ver mais
  • 2019-09-06Documento de conferência Acesso restrito Ver mais
  • The evaluation of CSR perception: a study in Portugal and Ukraine
    Publication . Sokil, Oksana; Ubreziová, Iveta; Eugénio, Teresa; Marques, Tânia
    2019-09-10Documento de conferência Acesso restrito Ver mais
  • Flow characteristics of gas injectors
    Publication . Ivanov, Zdravko; Stoyanov, Stoyan; Mihaylov, Veselin; Santos, Helder
    The operation of Internal Combustion Engine (ICE) with gaseous fuels is characterized by the specificity of the fuelling process. Nowadays the most common system is the one in which after lowering its pressure the gas fuel is delivered to the engine intake manifold by means of gas injectors. This leads to a difference in the laws of fuel supply relative to the original gasoline injection system that dispenses fuel in liquid phase. Theoretical research has been done and gas leakage has been found to be critical under engine normal operating conditions, that is, it depends on fuel pressure and not on the environment in which the fuel leaks (intake manifold). An experimental test stand was set-up and multiparametric characteristics of a common construction bottom feed gas injectors were determined experimentally under conditions very close to the real working ones
    2019-09-10Atas de conferência Acesso aberto Ver mais