Visible Light Communication in Vehicular Communication Applications

This paper addresses the issues related to the Visible Light Communication (VLC) usage in vehicular communication applications. We propose a Visible Light Communication system based on Vehicle-to-Vehicle, Vehicleto-Infrastructure and Infrastructure-to-Vehicle communications able to safely manage vehicles crossing through an intersection. By using the streetlamps, street lights and traffic signaling to broadcast information, the connected vehicles interact with one another and with the infrastructure. Using joint transmission, mobile optical receivers collect data, calculate their location for positioning and, concomitantly, read the transmitted data from each transmitter. As receivers and decoders, optical sensors with light filtering properties, are used. Bidirectional communication between the infrastructure and the vehicles is tested. To command the passage of vehicles safely queue/request/response mechanisms and temporal/space relative pose concepts are used. The results show that the innovative solutions for congested intersections are related to the introduction of split intersections. The results indicate that the V-VLC system increases safety by directly monitoring critical points such as queue formation and dissipation, relative speed thresholds, as well as inter-vehicle spacing.publishersversionpublishe

VLC Based Guidance System to Be Used by Mobile Users Inside Large Buildings

The main goal of this paper is a Visible Light Communication (VLC) based guidance system to be used by mobile users inside large buildings. This system is composed of several transmitters (ceiling luminaries), which transmit map information and path guidance messages. Mobile devices, with VLC support, decode the information. A mesh cellular hybrid structure is proposed. The luminaires, via VLC, deliver their geographic position and specific information to the users, making them available for whatever use they request. The communication protocol, coding/decoding techniques, and error control are examined. Bidirectional communication is implemented and the best route to navigate through venue calculated. We propose several guidance services and multi-person cooperative localization. By analyzing the results, it became clear that the system not only provides self-location, but also the capability to determine the direction of travel and to interact with information received in order to optimize the route towards a static or dynamic destination.publishersversionpublishe

A importância do contexto cultural para a comunicação empresarial: um breve enquadramento

O modo como as empresas olham cada vez mais para o mundo como o seu mercado potencial faz com que o sucesso dos negócios internacionais dependa em grande medida da eficácia da comunicação em contexto intercultural. Estudar e relacionar a comunicação intercultural e a comunicação empresarial faz por isso muito sentido. O que distingue a comunicação intercultural de outros tipos de comunicação é a interacção entre pessoas percebidas como diferentes de nós. No entanto, é fácil perdermo-nos neste conceito e nas suas implicações. Este texto procura, por isso, contextualizar a noção de cultura, os seus níveis e as suas dimensões, assim como identificar barreiras à comunicação intercultural. Uma análise e investigação mais profunda das teorias pode levar-nos a concordar ou a discordar sobre os seus resultados e sobre o que elas advogam. Porém, do nosso ponto de vista, esse não será o aspecto mais importante. Fundamental na sua leitura e revisão será a ajuda que nos dará a entender melhor a nossa cultura, a encontrar e a perceber as diferenças em relação às outras, a antecipar os riscos e as formas de minimizar o seu impacto, a tornar-nos comunicadores interculturais mais eficazes e, como consequência, a obter melhores resultados.The way in which companies increasingly look to the whole world as their potential market means that international business success largely depends on the effectiveness of intercultural communication. Thus, it makes sense to study and to link intercultural communication to international business and to business communication. What distinguishes intercultural communication from other types of communication is the interaction between people perceived as different from us. However, we can easily fail to understand these concepts and their implications. We will then try to address some issues such as culture, levels of cultures and dimensions of cultures, as well as some barriers to intercultural communication. Further analysis and investigation into these theories can lead us to agree or to disagree with them and with their results. But from our point of view, this is not the key aspect. What is important in reading and reviewing them is to get a better understanding of our own culture, to identify and understand the differences in relation to others, to anticipate the risks and the means to minimize their impact, to become more effective intercultural communicators and, consequently, to achieve better results

Reutilização de material fresado em camadas estruturais de pavimento : novas perspectivas

Na actualidade, a crescente preocupação com a protecção ambiental, que se verifica em todas as áreas, leva a que, a nível da Engenharia Rodoviária, sejam já utilizadas diversas técnicas de reciclagem de subprodutos resultantes de trabalhos de beneficiação e reforço de pavimentos flexíveis. Neste artigo enquadra-se o processo de reutilização de materiais recorrendo à mistura de material fresado com pó e cimento, dentro dos processos de reciclagem de pavimentos e apresentam-se resultados que permitem concluir que a técnica pode constituir uma alternativa à reutilização de subprodutos da construção, em substituição de camadas granulares de pavimento

Comunicação estratégica em contexto intercultural: desafios da utilização de um estudo de caso

Ao definirem uma estratégia integrada de comunicação para abordagem de novos mercados, as empresas enfrentam novos desafios causados pela distância, não só física, mas também cultural. Mas o que é a distância cultural? Como se encurta e como se torna a comunicação, a este nível, mais eficaz? De que forma a estratégia de comunicação integrada de marketing das empresas tem em conta as características específicas das culturas locais? Este foi o mote para um projecto de investigação que, no seu desenho, considerou a utilização de um estudo de caso: um processo empírico que investiga um fenómeno contemporâneo em profundidade e dentro do seu contexto de vida real, sobretudo quando as fronteiras entre o fenómeno e o contexto não são claramente evidentes. Contexto é precisamente um dos conceitos relevantes neste texto, a par de singularidade. Pelo contexto, externo e interno, cada empresa irá encontrar fórmulas muito singulares de tornar mais eficaz a comunicação intercultural. Ora o estudo de caso é precisamente o estudo do singular, do particular, do único e o investigador, por ser uma parte incontornável do processo de investigação, terá que analisar como o contexto pode afectar o seu trabalho. Em ambos os casos (do empresário e do investigador), a visão do mundo, as preferências e os valores irão influenciar a forma de actuar

Contribution for the reuse of rap material in pavements structural layers

O objectivo principal deste artigo é promover a utilização de material fresado em camadas estruturais de pavimento, reutilizando materiais provenientes da reconstrução de camadas de pavimentos flexíveis. Os resultados laboratoriais realizados sobre misturas de material fresado, pó de pedra e cimento (FPC) permitem concluir que uma camada de sub-base de pavimento flexível realizada com esta mistura, pode resultar numa camada de elevada resistência. A técnica é económica e ambientalmente justificada, dado que constitui uma solução para a reutilização de um subproduto da construção, reduzindo a necessidade de utilizar novos agregados. Por outro lado, o aumento da capacidade resistente da camada de sub-base realizada com FPC, pode traduzir-se na possibilidade de diminuir a espessura das restantes camadas de pavimento, reduzindo o consumo de novos agregados e ligantes betuminosos.The main purpose of this article is to promote the use of RAP (Reclaimed Asphalt Pavement) in pavement structural layers, reusing material produced by the reconstruction of flexible pavements layers. Laboratorial results made on mixtures of RAP material, stone powder and cement (FPC) allow concluding that a pavement sub-base layer made with this mixture can constitute a layer with an improved resistance. The technique is economic and environmentally justified, thus it represents a solution for the reuse of a construction by-product, reducing the use of new aggregates. By the other hand, the increase of resistance of the sub-base layer made with FPC, can allow reducing the thickness of other layers, reducing the consumption of new aggregates and bituminous binders

Root cause analysis of low throughput situations using boosting algorithms and the TreeShap analysis

Detecting and diagnosing the root cause of failures in mobile networks is an increasingly demanding and time consuming task, given its technological growing complexity. This paper focuses on predicting and diagnosing low User Downlink (DL) Average Throughput situations, using supervised learning and the Tree Shapley Additive Explanations (SHAP) method. To fulfill this objective, Boosting classification models are used to predict a failure/non-failure binary label. The influence of each counter on the overall model’s predictive performance is performed based on the TreeSHAP method. From the implemen tation of this technique, it is possible to identify the main causes of low throughput, based on the analysis of the most critical counters in fault detection. Furthermore, from the identification of these counters, it is possible to define a system for diagnosing the most probable throughput degradation cause. The described methodology allowed not only to identify and quantify low throughput situations in a live network due to the occurrence of misadjusted configuration parameters, radio problems and network capacity problems, but also to outline a process for solving them.info:eu-repo/semantics/publishedVersio

Applying ultrasound-assisted processing to obtain cellulose fibres from rice straw to be used as reinforcing agents

[EN] Rice straw (RS) is one of the most globally abundant agro-industrial residues. For its valorisation, a green combined ultrasound-reflux heating method was applied to obtain cellulose fibres (CF) from RS. The new method produced CF with a higher yield (37%) than the alkaline process (29%), more hydrophilic, and with a lower tendency to aggregate. Despite the slightly different degree of purification detected by the chemical and FTIR analysis, both fibres exhibited similar crystallinity, thermal behaviour, morphogeometric characteristics, and aspect ratio distributions (20¿60). Both CF showed similar reinforcing capabilities in methylcellulose/gum Arabic films, enhancing the film stretchability and resistance to break by about 33% and 20%. Non-noticeable changes in water vapour permeability and the light internal transmission were observed, indicating good compatibility CF-polymer matrix. Therefore, using the ultrasound-heating method to obtain CF is an eco-friendlier process than the alkaline treatment, supplying suitable fibres as industrial reinforcing agents.This work was supported by Generalitat Valenciana for the GrisoliaP/2019/115 Grant.Vieira-De Freitas, PA.; González Martínez, MC.; Chiralt, A. (2022). Applying ultrasound-assisted processing to obtain cellulose fibres from rice straw to be used as reinforcing agents. Innovative Food Science & Emerging Technologies. 76:1-14. https://doi.org/10.1016/j.ifset.2022.1029321147

Using rice straw fractions to develop reinforced, active PLA-starch bilayers for meat preservation

[EN] Bilayers from thermoplastic corn starch (TPS) and PLA were obtained, incorporating or not rice straw (RS) valorised fractions: active extract (es) into PLA and cellulose fibres (cf) into TPS films. The films were obtained by thermoprocessing while the bilayers were obtained by thermocompression of the different monolayers (TPS-PLA, TPScf-PLA, TPS-PLAes and TPScf-PLAes). TPS conferred oxygen barrier capacity to the laminates, which was improved by the cf incorporation. The extract slightly reduced the PLA resistance but improved their oxygen barrier capacity. The tensile and barrier properties of the bilayers revealed changes in the performance of each layer associated with the interlayer compound migration. The TPScf-PLAes bags exhibited noticeable antioxidant capacity when used in meat packaging and reduced microbial counts throughout cold storage. Therefore, these bilayers have considerable potential to extend the shelf-life of meat samples, preserving their quality and safety for longer, while using RS fractions permits its valorisation.Funding This work was supported by Generalitat Valenciana [grant number GrisoliaP/2019/115] and project PID2019-105207RB-I00/AEI/10.13039/501100011033. Funding for open access charge: CRUE-Universitat Politècnica de València.Vieira-De Freitas, PA.; González Martínez, MC.; Chiralt, A. (2023). Using rice straw fractions to develop reinforced, active PLA-starch bilayers for meat preservation. Food Chemistry. 405. https://doi.org/10.1016/j.foodchem.2022.13499040

Perfil compósito para colector solar, respectivo método de produção e utilização

A presente invenção diz respeito a um perfil compósito para caixa modular utilizada em colectores solares para aquecimento de águas para uso doméstico ou industrial cujas principais vantagens passam pela: produção através de um processo de extrusão, redução das perdas energéticas do colector solar devido ao design com perfil alveolar, fácil portabilidade devido a redução do peso por metro quadrado de painel, utilização de compósitos recicláveis na sua composição usando entre outros: borracha de pneu usado reciclada, redução dos tempos de montagem dos colectores solares, eliminação da necessidade de colocação de isolantes adicionais à caixa modular e redução dos custos de produção