Research on Workplace Safety Sign Compliance: Validation of a Virtual Environment Prototype

AbstractRecent studies have highlighted Virtual Environments (VEs) as feasible tools for conducting safety sign research. Conversely, guidelines on how to conduct such studies with workplace safety signs and older workers, is scarce. The nature of this study is justified by the fact that, as workers grow older, their ability to comply with such signs is adversely affected by age-related deficits. Therefore, the present pilot study sought to assess the quality of a VE prototype that was specifically designed to conduct safety sign research with middle-aged working adults (50-65 yrs). Using a work-related context, and a sample of twelve workers, the study consisted of two key moments: 1) to examine the workers’ interaction, by evaluating their behavioral compliance; and 2) to analyze their overall user experience, by assessing their subjective perceptions. In order to undergo such an evaluation, the following VE interaction issues were addressed: simulator sickness, sense of presence, level of engagement and hazard perception. Both behavioral and subjective data were gathered from three sources: observation, post-hoc questionnaires, and semi-structured interviews. Results reveal that: 1) the VE's workplace safety signs were ineffective in promoting behavioral compliance; and 2) despite the occurrence of some simulator sickness, overall, participants had high levels of presence and engagement, as well as correctly perceived the VE's hazard. In conclusion, the VE prototype proved to be adequate for the study's purpose

Vector-like Quarks at the Origin of Light Quark Masses and Mixing

We show how a novel fine-tuning problem present in the Standard Model can be solved through the introduction of a single flavour symmetry G, together with three $Q = - 1/3$ quarks, three $Q = 2/3$ quarks, as well as a complex singlet scalar. The symmetry G is extended to the additional fields and it is an exact symmetry of the Lagrangian, only spontaneously broken by the vacuum. Specific examples are given and a phenomenological analysis of the main features of the model is presented. It is shown that even for vector-like quarks with masses accessible at the LHC, one can have realistic quark masses and mixing, while respecting the strict constraints on process arising from flavour changing neutral currents (FCNC). The vector-like quark decay channels are also described.Comment: 25 pages, no figure

Child-persona: How to Bring them to Reality?

AbstractThe purpose of the investigation described in this article is the creation of a Persona questionnaire, which will be used as reference to design a political educational game for children. There are several methodological strategies for the development of adult- based Personas that are used in information systems. However, there is little information on how to create Personas for systems used by children. Some questions we addressed in this context are: What kind of items can best characterize a child's lifestyle, needs, frustrations, and expectations? How to design questions in order to gather data efficiently? A three-phase methodology was designed to answer these issues: 1) Semi-structured interviews to access the most important aspects of lifestyle, needs, frustrations and expectations; 2) Creation and oral administration of a questionnaire aimed at verifying children's difficulties in answering questions; 3) Questionnaire review and application in a classroom situation with a different set of children. The results enable the development of a questionnaire focused on the child's characteristics. In the next phase of this study, this questionnaire will be applied to a sample of 500 children to create child-Personas for a political game

Fatores Determinantes da Performance Inovadora de Empresas de Serviços Portuguesas vs. Norueguesas

No contexto de mercados globais, o setor dos serviços tem vindo a ser objeto de numerosos estudos, que o posicionam como um setor crítico e muito relevante para a promoção, a adoção e a rápida difusão da inovação, nas economias de diferentes países. Em face dos novos desafios colocados aos mercados globais, a inovação tornou-se essencial para as empresas se manterem competitivas e assegurarem a sua sobrevivência. Com o objetivo de contribuir para os estudos na área da inovação, a presente dissertação analisa os fatores determinantes da performance inovadora das empresas de serviços, abordando dois grandes grupos de empresas, atendendo à intensidade de incorporação do fator produtivo: conhecimento; designadamente, as empresas de serviços intensivos em conhecimento (KIS) e as empresas de serviços menos intensivos em conhecimento (LKIS). Fazendo uso de dados secundários coligidos a partir do Community Innovation Survey (CIS) - CIS 2010, efetuou-se um estudo comparativo aplicado a 2381 pequenas e médias empresas (PME), em Portugal, e 2535 PME, na Noruega. Procedeu-se à estimação de modelos Binários de Valores extremos (Gombit), que permitiram avaliar as relações entre as competências tecnológicas, de recursos humanos e organizacionais, das relações com o mercado e das ligações de coopetição com a performance inovadora das empresas, em termos de inovação de produto, serviço, processo e eco-inovação. As evidências empíricas agora obtidas evidenciam que a maioria dos grupos de fatores determinantes identificados na revisão de literatura, influencia de forma positiva e significativa a performance inovadora das empresas KIS e LKIS, em ambos os países, assim como, se constata uma influência positiva e significativa da coopetição sobre a performance inovadora das empresas em estudo.In the context of global markets, the services sector has been the subject of numerous studies, where it is positioned as a critical and very relevant sector for the promotion, adoption and rapid diffusion of innovation, in different countries. Regarding the major challenges facing global markets, innovation has become essential for companies to remain competitive and ensure their survival. In order to contribute to studies in the area of innovation, this dissertation analyzes the determining factors of the innovative performance of service companies, addressing two large groups of companies, taking into account the intensity of incorporation of the production factor: knowledge; namely, knowledge-intensive services (KIS) companies and less knowledge-intensive service (LKIS) companies. Using secondary data collected from the Community Innovation Survey (CIS) - CIS 2010, a comparative study was carried out applied to 2381 small and medium-sized enterprises (SMEs), in Portugal, and 2535 SMEs, in Norway. Several Binary models of extreme values (Gombit) were estimated, which made it possible to assess the relationship between technological, human and organizational competences, relations with the market and coopetition links with the innovative performance of companies, in terms of product, service, process and eco-innovation. The empirical evidence now obtained shows that most groups of determining factors identified in the literature review, positively and significantly influence the innovative performance of the KIS and LKIS companies, in both countries, as well as, there is a positive and significant influence of coopetition on the innovative performance of the companies under study

Away from the edges: a new Solutrean site in interior Iberia. Foz do Medal Left Bank, Sabor Valley, Northeast Portugal (NW Iberia)

info:eu-repo/semantics/publishedVersio

Plasmids Increase the Competitive Ability of Plasmid-Bearing Cells Even When Transconjugants Are Poor Donors, as Shown by Computer Simulations

Bacterial cells often suffer a fitness cost after conjugative plasmids’ entry because these cells replicate slower than plasmid-free cells. Compensatory mutations may appear after tens of or a few hundred generations, reducing or eliminating this cost. A previous work based on a mathematical model and computer simulations has shown that plasmid-bearing cells already adapted to the plasmid may gain a fitness advantage when plasmids transfer into neighboring plasmid-free cells because these cells are still unadapted to the plasmid. These slow-growing transconjugants use fewer resources, which can benefit donor cells. However, opportunities for compensatory mutations in transconjugants increase if these cells become numerous (through replication or conjugation). Moreover, transconjugants also gain an advantage when transferring the plasmid, but the original donors may be too distant from conjugation events to gain an advantage. To understand which consequence prevails, we performed further computer simulations allowing versus banning transfer from transconjugants. The advantage to donors is higher if transconjugants do not transfer plasmids, mainly when donors are rare and when the plasmid transfer rate (from donors) is high. These results show that conjugative plasmids are efficient biological weapons even if the transconjugant cells are poor plasmid donors. After some time, conjugative plasmids gain other host-benefit genes, such as virulence and drug-resistance.info:eu-repo/semantics/publishedVersio

Contributo para a utilização sustentável de água na Marina de Cascais

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente, Perfil Gestão e Sistemas AmbientaisCom o aumento da pressão sobre os recursos naturais e em particular sobre os recursos hídricos, devido a fatores como as alterações climáticas e o aumento da população mundial, a água é nos dias de hoje um recurso escasso e altamente valioso. Para uma melhor gestão dos recursos hídricos, é necessário criar novas estratégias que permitam reduzir o consumo de água potável, tornar possível a reutilização de água e também o aproveitamento de águas pluviais para diversas atividades, de forma a garantir uma utilização mais sustentável dos recursos hídricos. O objetivo desta dissertação é desenvolver uma avaliação integrada sobre o potencial de utilização sustentável de água na marina de Cascais, nomeadamente através de uma abordagem que permita contribuir para a melhoria de eficiência, quer em termos da melhor utilização do recurso, quer na perspetiva de uma melhor gestão económica do mesmo. Neste caso de estudo será apresentada uma avaliação do potencial de utilização de águas pluviais na rega dos espaços verdes e na náutica na marina de Cascais, analisando os seus benefícios económicos e ambientais, bem como algumas estratégias e medidas que poderão levar à redução de consumo de água potável. Será desenvolvida uma caracterização detalhada de todo o sistema de abastecimento de água na marina, bem como do seu potencial para recolha e armazenamento de águas Pluviais. E, desta forma, obter as informações necessárias que permitam tomar decisões estratégicas, e fundamentadas para uma utilização racional da água, tendo em conta a viabilidade técnica, ambiental e económica. O presente estudo efetuado na marina de Cascais revelou que os SAAP em marinas são atrativos do ponto de vista económico, e ainda, que os reservatórios em chapa metálica são mais competitivos do que em betão, apesar da menor durabilidade

Use of data mining techniques to explain the primary factors influencing water sensitivity of asphalt mixtures

The water sensitivity of asphalt mixtures affects the durability of the pavements, and it depends on several parameters related to its composition (aggregates and binder) and the production and application processes. One of the main parameters used in the European Standards to measure the water sensitivity of asphalt mixtures is the indirect tensile strength ratio (ITSR). Therefore, this work aims to obtain a predictive model of ITSR of asphalt mixtures using several parameters that affect water sensitivity and assess their relative importance. The database used to develop the model comprises thirteen parameters collected from one hundred sixty different asphalt mixtures. Data Mining techniques were applied to process the data using Multiple Regression, Artificial Neural Networks, and Support Vector Machines (SVM). The different metrics analysed showed that SVM is the best predictive model of the ITSR (mean absolute deviation of 0.116, root mean square error of 0.150 and Pearson correlation coefficient of 0.667). The application of a sensitivity analysis indicates that the binder content is the parameter that most influences the water sensitivity of asphalt mixtures (26%). However, this property depends simultaneously on other factors such as the characteristics of the coarse and fine aggregates (24.9%), asphalt binder characteristics (19.3%) and the use of additives (10%).Acknowledgements This work was partly financed by FCT/MCTES through national funds (PIDDAC) under the R & D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE) , under reference UIDB/04029/2020