2,685 research outputs found

    Resilience in Highways: Proposal of Roadway Redundancy Indicators and Application in Segments of the Brazilian Network

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    With the growing realization that transport systems must operate satisfactorily not only in typical situations, but also in adverse circumstances, ensuring redundancies in road systems has gained crucial importance. In this context, several methods have been proposed for measuring the vulnerabilities and resilience of transport systems. However, a simple metric to understand and quantify the degree of redundancy of a given road segment is still necessary, mainly to guide the responsible bodies regarding the need for intervention or special care with certain sections of the system. Thus, this paper proposes a redundancy indicator based on network analyses in the vicinity of an element. The proposed indicator was first calculated on nine application examples and then on a substantial sample of the Brazilian road network (~10% of segments). The results demonstrate that the indicator can satisfactorily describe the variety of cases in the Brazilian network, capturing cases where there is significant redundancy in the elements, as in some regions of the Southeast and South; or cases of very low redundancy, such as the sparse grid in the north of the country. It was also verified that the indicator has a particular sensitivity to parameters of the defined function, requiring further research for an acceptable calibration.Comment: 21 pages, 9 figures, 2 tables. Presented at ANPET 2023, Santos, S\~ao Paulo, Brazi

    An IEEE 802.15.4 protocol implementation (in nesC/TinyOS): reference guide v1.0

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    This technical report is to provide a reference guide to the implementation of the IEEE 802.15.4 protocol in nesC/TinyOS for the MICAz motes. The implementation is provided as a tool that can be used to implement, test and evaluate the current functionalities defined in the protocol standard as well as to enable the development of functionalities not yet implemented and new add-ons to the protocol

    Effect of Pre-Hydrolysis Reaction Conditions on Xylooligosaccharides Extraction in Eucalyptus Globulus

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    Pre-hydrolysis-kraft of Eucalyptus globulus by autohydrolysis (batch) and with dilute acid hydrolysis (flow-through reactor) were explored in this study, to examine the recovery of xylooligosaccharides (XOs) from the pre-hydrolysis treatment. The results of this work support the potential reuse of the hydrolysate to increase the recovery yield of added value compounds. The pH of the dilute acid hydrolysis was maintained at 3.5 with acetic acid, to mimic the conditions of the batch reactor medium (autohydrolysis). An increase of XOs recovered was evident when the pre-treatment was in the flow-through reactor instead of the batch reactor. In the latter, a high concentration of furfural was recovered, showing the influence of time in XO conversion through hydrolysis. The total yield of pulp was higher in the flow-through reactor (36.4%) in comparison with the batch system (34.5%) after kraft pulping, which was expected, given the increasing time that the hydrolysate was present in the reactor; however, the difference was small and could have been the result of precipitated compounds in the latter, so this needs further analysis. Keywords: cellulose, Eucalyptus globulus, pre-hydrolysis kraft, xylooligosaccharide

    Contributos para suportar o desenvolvimento de sistemas de diálogo

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    With the increase of technology present in our daily routine, a specific area rose exponentially. Spoken dialogue systems are increasingly popular and useful: they provide an easier and more versatile access to large and diverse sets of information. Nowadays there is a vast knowledge base regarding this topic, as well as different systems capable of performing numerous tasks just by simply processing voice input. There are also an increasing set of tools for their development. Despite recent advances, development of dialog systems continues to be challenging. The main objective of this thesis is to contribute and make possible and simple the development of new dialogue systems for Portuguese: by selecting, adapting and combining existing tools/frameworks. Supported by the enhancements made to the selected basis framework, two different dialog systems were developed: the first is an assistant aimed at a Smart Home environment - one of areas that benefited the most with the development of dialog systems - and the second targeting accessible tourism. The first assistant was developed aligned with the Smart Green Homes project. It implied the definition of scenarios and requirements that later helped defining the ontology and the system. Another requirement for this system was the inclusion of the back-end system developed previously as part of the Smart Green Homes project. The second was aligned with the project ACTION in the area of Tourism. It was developed for users with accessibility needs, e.g., impaired movement or vision.Com o aumento da tecnologia presente na nossa rotina diária, uma área específica subiu exponencialmente. Os sistemas de diálogo são cada vez mais populares e úteis: proporcionam um acesso mais fácil e versátil a grandes e diversificados conjuntos de informação. Hoje em dia existe uma vasta base de conhecimento sobre este tema, bem como diferentes sistemas capazes de executar inúmeras tarefas através do processamento de uma entrada de voz. Há também um conjunto crescente de ferramentas para o seu desenvolvimento. Apesar dos avanços recentes, o desenvolvimento de sistemas de diálogo continua a ser um desafio. O principal objetivo desta tese é contribuir e tornar possível e simples o desenvolvimento de novos sistemas de diálogo que suportem português: selecionando, adaptando e combinando ferramentas existentes. Baseado nas melhorias feitas nas ferramentas bases selecionadas, foram desenvolvidos dois sistemas de diálogo diferentes: o primeiro é um assistente dirigido a um ambiente Smart Home - uma das áreas que mais beneficiou com o desenvolvimento de sistemas de diálogo - e o segundo visando o turismo acessível. O primeiro assistente foi desenvolvido alinhado com o projeto Smart Green Homes. Implicou a definição de cenários e requisitos que mais tarde ajudaram a definir a ontologia e o sistema. Outro requisito para este sistema foi a inclusão do sistema back-end desenvolvido anteriormente como parte do projeto Smart Green Homes. O segundo assistente foi alinhado com o projeto ACTION na área do Turismo. Foi desenvolvido para utilizadores com necessidades de acessibilidade, por exemplo, deficiência motora ou invisualidade.Mestrado em Engenharia de Computadores e Telemátic

    On the use of IEEE 802.15.4/ZigBee as federating communication protocols for Wireless Sensor Networks

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    Tese de mestrado. Redes e Serviços de Comunicação. Faculdade de Engenharia. Universidade do Porto, Instituto Superior de Engenharia. 200
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