Recursos de colección

Repositório do Instituto Politénico de Castelo Branco (14.319 recursos)

O Repositório Científico do Instituto Politécnico de Castelo Branco tem como objectivos fundamentais a divulgação, a preservação em formato digital e a partilha do conhecimento científico gerado na instituição, constituindo-se numa ferramenta de valor acrescentado porque permite aumentar a visibilidade e o impacto da investigação desenvolvida.

ESTCB - Escola Superior de Tecnologia

Mostrando recursos 1 - 20 de 424

  1. Desenvolvimento e teste de uma smartbox versátil para o chão de fábrica

    Torres, Pedro; Dionísio, Rogério
    O surgimento de várias inovações tecnológicas permitiu a digitalização e a transformação da indústria, acompanhando o paradigma da Indústria 4.0. Tecnologias ligadas à robótica, aos sensores inteligentes, ao fabrico assistido por computador, à Internet das Coisas ou à Inteligência Artificial permitem a interligação entre os mundos físicos e virtuais. A interoperação entre todos estes domínios do saber é o princípio para transformar o processo de produção e criar uma fábrica inteligente. O foco deste artigo centra-se no desenvolvimento e teste de uma smartBox, capaz de comunicar eficientemente com os equipamentos no chão de fábrica e integrá-los em plataformas de IIOT (Industrial Internet of Things). À smartBox estão acopladas cartas e...

  2. Ontology for autonomous robotics

    Gonçalves, P.J.S.; Li, Howard; Fiorini, Sandro; Olszewska, Joanna
    Creating a standard for knowledge representation and reasoning in autonomous robotics is an urgent task if we consider recent advances in robotics as well as predictions about the insertion of robots in human daily life. Indeed, this will impact the way information is exchanged between multiple robots or between robots and humans and how they can all understand it without ambiguity. Indeed, Human Robot Interaction (HRI) represents the interaction of at least two cognition models (Human and Robot). Such interaction informs task composition, task assignment, communication, cooperation and coordination in a dynamic environment, requiring a flexible representation. Hence, this paper...

  3. Ontology for autonomous robotics

    Gonçalves, P.J.S.; Li, Howard; Fiorini, Sandro; Olszewska, Joanna
    Creating a standard for knowledge representation and reasoning in autonomous robotics is an urgent task if we consider recent advances in robotics as well as predictions about the insertion of robots in human daily life. Indeed, this will impact the way information is exchanged between multiple robots or between robots and humans and how they can all understand it without ambiguity. Indeed, Human Robot Interaction (HRI) represents the interaction of at least two cognition models (Human and Robot). Such interaction informs task composition, task assignment, communication, cooperation and coordination in a dynamic environment, requiring a flexible representation. Hence, this paper...

  4. Numerical modal analysis of vibrations in a three-phase linear switched reluctance actuator

    Salvado, José; Calado, Maria do Rosário; Espiríto Santo, António; Guerman, Anna
    This paper addresses the problem of vibrations produced by switched reluctance actuators, focusing on the linear configuration of this type of machines, aiming at its characterization regarding the structural vibrations. The complexity of the mechanical system and the number of parts used put serious restrictions on the effectiveness of analytical approaches. We build the 3D model of the actuator and use finite element method (FEM) to find its natural frequencies. The focus is on frequencies within the range up to nearly 1.2 kHz which is considered relevant, based on preliminary simulations and experiments. Spectral analysis results of audio signals from experimental modal...

  5. Numerical modal analysis of vibrations in a three-phase linear switched reluctance actuator

    Salvado, José; Calado, Maria do Rosário; Espiríto Santo, António; Guerman, Anna
    This paper addresses the problem of vibrations produced by switched reluctance actuators, focusing on the linear configuration of this type of machines, aiming at its characterization regarding the structural vibrations. The complexity of the mechanical system and the number of parts used put serious restrictions on the effectiveness of analytical approaches. We build the 3D model of the actuator and use finite element method (FEM) to find its natural frequencies. The focus is on frequencies within the range up to nearly 1.2 kHz which is considered relevant, based on preliminary simulations and experiments. Spectral analysis results of audio signals from experimental modal...

  6. Load-based generic polca: performance assessement using simulation

    Fernandes, N.O.G.; Carmo-Silva, S.
    POLCA (i.e. Paired-cell Overlapping Loops of Cards with Authorization) is a card-based decision support system for production control, developed to support the adoption of Quick Response Manufacturing. Two variants of POLCA have been proposed in the literature to improve POLCA performance: Load Based POLCA and Generic POLCA. In this paper, we combine these two variants into a single production control system and analyse its performance for different backlog-sequencing rules. The results of a simulation study carried out for a make-to-order flow shop, support the strategy of combining these two POLCA variants and show that capacity-slack backlog sequencing based on corrected...

  7. Load-based generic polca: performance assessement using simulation

    Fernandes, N.O.G.; Carmo-Silva, S.
    POLCA (i.e. Paired-cell Overlapping Loops of Cards with Authorization) is a card-based decision support system for production control, developed to support the adoption of Quick Response Manufacturing. Two variants of POLCA have been proposed in the literature to improve POLCA performance: Load Based POLCA and Generic POLCA. In this paper, we combine these two variants into a single production control system and analyse its performance for different backlog-sequencing rules. The results of a simulation study carried out for a make-to-order flow shop, support the strategy of combining these two POLCA variants and show that capacity-slack backlog sequencing based on corrected...

  8. Computational intelligence applied to discriminate bee pollen quality and botanical origin

    Gonçalves, P.J.S.; Estevinho, L.M.; Pereira, A.P.; Sousa, J.M.C.; Anjos, O.
    The aim of this work was to develop computational intelligence models based on neural networks (NN), fuzzy models (FM), and support vector machines (SVM) to predict physicochemical composition of bee pollen mixture given their botanical origin. To obtain the predominant plant genus of pollen (was the output variable), based on physicochemical composition (were the input variables of the predictive model), prediction models were learned from data. For the inverse case study, input/output variables were swapped. The probabilistic NN prediction model obtained 98.4% of correct classification of the predominant plant genus of pollen. To obtain the secondary and tertiary plant genus...

  9. Computational intelligence applied to discriminate bee pollen quality and botanical origin

    Gonçalves, P.J.S.; Estevinho, L.M.; Pereira, A.P.; Sousa, J.M.C.; Anjos, O.
    The aim of this work was to develop computational intelligence models based on neural networks (NN), fuzzy models (FM), and support vector machines (SVM) to predict physicochemical composition of bee pollen mixture given their botanical origin. To obtain the predominant plant genus of pollen (was the output variable), based on physicochemical composition (were the input variables of the predictive model), prediction models were learned from data. For the inverse case study, input/output variables were swapped. The probabilistic NN prediction model obtained 98.4% of correct classification of the predominant plant genus of pollen. To obtain the secondary and tertiary plant genus...

  10. Estudo empírico do desempenho dos modelos de gestão de filas FIFO, WFQ e CBWFQ em sistemas reais

    Sousa, Celso; Fonte, Alexandre
    As aplicações multimédia (e.g., voz ou vídeo) exigem às redes IP um serviço de comunicação com baixa latência, baixas taxas de perdas de pacotes, e requisitos mínimos de largura de banda. Diferentes arquiteturas de Qualidade de Serviço (QoS) foram propostas e desenvolvidas por dois grupos do IETF, o modelo IntServ e o modelo, um pouco mais recente, DiffServ. Os fabricantes de equipamento de rede adotaram as suas próprias implementações destes modelos nos seus equipamentos de encaminhamento IP ou de comutação multicamada, para além do modelo Best-Effort. Neste trabalho, pretende-se avaliar a eficácia da implementação DiffServ realizada por um dos principais...

  11. Estudo empírico do desempenho dos modelos de gestão de filas FIFO, WFQ e CBWFQ em sistemas reais

    Sousa, Celso; Fonte, Alexandre
    As aplicações multimédia (e.g., voz ou vídeo) exigem às redes IP um serviço de comunicação com baixa latência, baixas taxas de perdas de pacotes, e requisitos mínimos de largura de banda. Diferentes arquiteturas de Qualidade de Serviço (QoS) foram propostas e desenvolvidas por dois grupos do IETF, o modelo IntServ e o modelo, um pouco mais recente, DiffServ. Os fabricantes de equipamento de rede adotaram as suas próprias implementações destes modelos nos seus equipamentos de encaminhamento IP ou de comutação multicamada, para além do modelo Best-Effort. Neste trabalho, pretende-se avaliar a eficácia da implementação DiffServ realizada por um dos principais...

  12. Multiview real-time media distribution for next generation networks

    Marques, Hugo; Silva, Hélio; Logota, Evariste; Rodriguez, Jonathan; Vahid, Seiamak; Tafazolli, Rahim
    With the massive deployment of broadband access to the end-users, the continuous improvement of the hardware capabilities of end devices and better video compression techniques, acceptable conditions have been met to unleash over-the-top bandwidth demanding and time-stringent P2P applications, such as multiview real-time media distribution. Such applications enable the transmission of multiple views of the same scene, providing consumers with a more immersive visual experience. This article proposes an architecture to distribute multiview real-time media content using a hybrid DVB-T2, client-server and P2P paradigms, supported by an also novel QoS solution. The approach minimizes packet delay, interar- rival jitter, inter-ISP...

  13. Multiview real-time media distribution for next generation networks

    Marques, Hugo; Silva, Hélio; Logota, Evariste; Rodriguez, Jonathan; Vahid, Seiamak; Tafazolli, Rahim
    With the massive deployment of broadband access to the end-users, the continuous improvement of the hardware capabilities of end devices and better video compression techniques, acceptable conditions have been met to unleash over-the-top bandwidth demanding and time-stringent P2P applications, such as multiview real-time media distribution. Such applications enable the transmission of multiple views of the same scene, providing consumers with a more immersive visual experience. This article proposes an architecture to distribute multiview real-time media content using a hybrid DVB-T2, client-server and P2P paradigms, supported by an also novel QoS solution. The approach minimizes packet delay, interar- rival jitter, inter-ISP...

  14. A numerical study of the effect of single overloads on plasticity induced crack closure

    Baptista, J.B.; Antunes, F.V.; Correia, L.; Branco, R.
    In this work, the effect of single overloads on plasticity induced crack closure is studied. An elastic-plastic finite element model was developed and the crack opening level was calculated from the contact forces along the crack flank. The effects of the loading parameters and stress state are analysed, and the mechanisms behind crack closure variations are identified. An overload is a traumatic event that eliminates material’s memory relative to the load history. Crack tip blunting is the mechanism behind this memory loss, since it eliminates crack closure. Material hardening has a major relevance on the evolution of plastic blunting, which was evident in the variation of...

  15. A numerical study of the effect of single overloads on plasticity induced crack closure

    Baptista, J.B.; Antunes, F.V.; Correia, L.; Branco, R.
    In this work, the effect of single overloads on plasticity induced crack closure is studied. An elastic-plastic finite element model was developed and the crack opening level was calculated from the contact forces along the crack flank. The effects of the loading parameters and stress state are analysed, and the mechanisms behind crack closure variations are identified. An overload is a traumatic event that eliminates material’s memory relative to the load history. Crack tip blunting is the mechanism behind this memory loss, since it eliminates crack closure. Material hardening has a major relevance on the evolution of plastic blunting, which was evident in the variation of...

  16. Caraterização de patologias do património edificado da cidade de Castelo Branco: diagnóstico e intervenção

    Costa, Cátia de Jesus Simão Dias
    Relatório de Estágio apresentado à Escola Superior de Tecnologia do Instituo Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Construção Sustentável, realizado sob orientação científica da Professora Doutora Cristina Calmeiro dos Santos, do Instituto Politécnico de Castelo Branco.

  17. Caraterização de patologias do património edificado da cidade de Castelo Branco: diagnóstico e intervenção

    Costa, Cátia de Jesus Simão Dias
    Relatório de Estágio apresentado à Escola Superior de Tecnologia do Instituo Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Construção Sustentável, realizado sob orientação científica da Professora Doutora Cristina Calmeiro dos Santos, do Instituto Politécnico de Castelo Branco.

  18. Affordable LTE network benchmarking based on transport fleets

    Dionísio, Rogério; Marques, Paulo; Marques, Hugo; Alves, Tiago; Pereira, Luís; Silva, Fernando; Ribeiro, Jorge
    “© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”

  19. Affordable LTE network benchmarking based on transport fleets

    Dionísio, Rogério; Marques, Paulo; Marques, Hugo; Alves, Tiago; Pereira, Luís; Silva, Fernando; Ribeiro, Jorge
    “© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”

  20. Real-time tourists counting and tracking system for management of nature trails in naturtejo global geopark (Portugal)

    Dionísio, Rogério; Marques, Paulo; Silva, F.P.; Rodrigues, J.; Carvalho, C.N.
    This paper presents a counting system project for the Naturtejo Global Geopark, which is structured in two phases. The objective of the first phase was to develop, install and test an electronic system able to remotely count the number of visitors on the Naturtejo Geopark walking routes and touristic sites. The data is reported through a web interface. A Pilot test is currently installed on Trail PR3 – “Fossil’s Route”, near the village of Penha Garcia. Since May 2015, more than 6000 tourists where monitored. The second phase of the project aims to track tourists based on the detection of...

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