4,644 research outputs found

    Central polynomials for matrix algebras over the Grassmann algebra

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    In this work, we describe a method to construct central polynomials for F-algebras where F is a field of characteristic zero. The main application deals with the T-prime algebras Mn(E), where E is the infinite- dimensional Grassmann algebra over F, which play a fundamental role in the theory of PI-algebras. The method is based on the explicit decomposition of the group algebra FSn. AMS Classification 2000: Primary 16R10, Secondary 16W50, 15A75. Keywords: Polynomial identities, central polynomials, Grassmann algebra. 

    Automatic nurse allocation based on a population algorithm for home health care

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    The provision of home health care services is becoming an important research area, mainly because in Portugal the population is ageing and it is necessary to perform home care services. Home care visits are organized taking into account the medical treatments and general support that elder/sick people need at home. This health service can be provided by nurses teams from Health Units, requiring some logistics for this purpose. Usually, the visits are manually planned and without computational support. The main goal of this work is to carry out the automatic nurse’s allocation of home care visits, of one Bragança Health Unit, in order to minimize the nurse’s workload balancing, spent time in all home care visits and, consequently, reduce the costs involved. The developed methodology was coded in MatLab Software and the problems were efficiently solved by the particle swarm optimization method. The nurse’s allocation solution of home care visits for the presented case study shows a significant improvement and reduction in the maximum time, in the nurse workload balancing, as well as the patients waiting time.This work has been supported by COMPETE:POCI-01-0145-FEDER-007043 and FCT - Fundação para a Ciência e Tecnologia within the project UID/CEC/00319/2019

    Multi-agent system specification for distributed scheduling in home health care

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    Nowadays, scheduling and allocation of resources and tasks becomes a huge and complex challenge to the most diverse industrial areas, markets, services and health. The problem with current scheduling systems is that their management is still done manually or using classical optimization methods (usually static, time-consuming) and centralized approaches. However, opportunities arise to decentralize solutions with smart systems, which enable the distribution of the computational effort, the flexibility of behaviours and the minimization of operating times and operational planning costs. The paper proposes the specification of a Multi-agent System (MAS) for the Home Health Care (HHC) scheduling and allocation. The MAS technology enables the scheduling of intelligent behaviours and functionalities based on the interaction of agents, and allows the evolution of current strategies and algorithms, as it can guarantee the fast response to condition changes, flexibility and responsiveness in existing planning systems. An experimental HHC case study was considered to test the feasibility and effectiveness of the proposed MAS approach, the results demonstrating promising qualitative and quantitative indicators regarding the efficiency and responsiveness of the HHC scheduling.This work has been supported by FCT—Fundação para a Ciência e a Tecnologia within the R&D Units Projects Scope: UIDB/00319/2020 and UIDB/05757/2020. Filipe Alves is supported by FCT Doctorate Grant Reference SFRH/BD/143745/2019

    Cognitive performance in childhood: mother and urban environment make the difference

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    Apesar das controvérsias sobre o conceito e a avaliação da inteligência, o desempenho cognitivo assume um papel fundamental no contexto educativo e são múltiplos os fatores que lhe estão associados. Este estudo toma uma amostra aleatória e representativa de 1201 crianças do 2.º ciclo do ensino básico de escolas públicas portuguesas, com idades entre 9 e 14 anos. Discute-se o impacto das variáveis sociofamiliares (profissão da mãe e do pai, escolaridade da mãe e do pai e meio de pertença urbano vs rural). Os resultados destacam a relevância dessas variáveis para a explicação do desempenho cognitivo dos alunos, especialmente a escolaridade da mãe e o meio urbano de proveniência. Apresentam-se considerações práticas voltadas à equidade do sistema educativo.Despite the controversies over the concept and evaluation of intelligence, cognitive achievement plays a fundamental role in educational context, and multiple factors are related to it. The current study uses a random and representative sample of 1201 2nd grade children from Portuguese public schools, between 9 and 14 years old. This study aims to discuss the impact of social and familial variables (mother and father’s jobs, mother and father’s educational level, and urban or rural environment of belonging). The results highlight the importance of social and familial variables as an explanation to students’ cognitive achievement, with great relevance to mother’s educational level and urban environment of belonging. Practical considerations aiming a better equity in educational system are presented.info:eu-repo/semantics/publishedVersio

    Detection of RHDV strains in the Iberian hare (Lepus granatensis): earliest evidence of rabbit lagovirus cross-species infection

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.Rabbit hemorrhagic disease virus (RHDV) is a highly lethal Lagovirus, family Caliciviridae, that threatens European rabbits (Oryctolagus cuniculus). Although a related virus severely affects hares, cross-species infection was only recently described for new variant RHDV in Cape hares (Lepus capensis mediterraneus). We sequenced two strains from dead Iberian hares (Lepus granatensis) collected in the 1990s in Portugal. Clinical signs were compatible with a Lagovirus infection. Phylogenetic analysis of the complete capsid gene positioned them in the RHDV genogroup that circulated on the Iberian Peninsula at that time. This is the earliest evidence of RHDV affecting a species other than European rabbits.This work was supported by FCT (Fundação para a Ciência e a Tecnologia; research project ref.: FCT-ANR/BIABIC/0043/2012). FCT also supported the doctoral grants of AML and AP (refs.: SFRH/BD/78738/2011 and SFRH/BD/71252/2010) and the FCT Investigator grant of JA (ref.: IF/01396/2013). “Genomics Applied To Genetic Resources” co-financed by North Portugal Regional Operational Programme 2007/2013 (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF), also supported this work.Peer Reviewe

    Mathematics achievement in engineering : an exploratory study with MIEGI students

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    Mathematics is a discipline that appears on the syllabus of many courses, including courses in engineering, where it is an essential discipline to the formation of all future engineers, whatever their field of study and work. Despite that, engineering students tend to reveal difficulties with courses based on mathematics. The factors that influence learning mathematics have been the subject of study for several researchers around the world. Researchers attempt to identify variables that explain mathematics achievement, but fail to address university students. In this paper, we present the results of an exploratory study based on industrial engineering students of University of Minho, concerning their grades in the courses of statistics and numerical methods. The preliminary results show that gender is an unexpected and significant factor.Fundação para a Ciência e a Tecnologia (FCT

    The sustainable home health care process based on multi-criteria decision-dupport

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    The increase in life expectancy has led to a growing demand for Home Health Care (HHC) services. However, some problems can arise in the management of these services, leading to high computational complexity and time-consuming to obtain an exact and/or optimal solution. This study intends to contribute to an automatic multi-criteria decision-support system that allows the optimization of several objective functions simultaneously, which are often conflicting, such as costs related to travel (distance and/or time) and available resources (health professionals and vehicles) to visit the patients. In this work, the HHC scheduling and routing problem is formulated as a multi objective approach, aiming to minimize the travel distance, the travel time and the number of vehicles, taking into account specific constraints, such as the needs of patients, allocation variables, the health professionals and the transport availability. Thus, the multi-objective genetic algorithm, based on the NSGA-II, is applied to a real-world problem of HHC visits from a Health Unit in Bragança (Portugal), to identify and examine the different compromises between the objectives using a Pareto-based approach to operational planning. Moreover, this work provides several efficient end-user solutions, which were standardized and evaluated in terms of the proposed policy and compared with current practice. The outcomes demonstrate the significance of a multi-criteria approach to HHC services.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CeDRI (UIDB/05757/2020 and UIDP/05757/2020), SusTEC (LA/P/0007/2021) and ALGORITMI Research Centre / LASI (UIDB/00319/2020). Filipe Alves thanks the FCT for supporting its research with the Ph.D. grant SFRH/BD/143745/2019.info:eu-repo/semantics/publishedVersio

    Salt weathering of natural stone: a review of comparative laboratory studies

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    Natural stone is an important component of historical heritage (buildings and art objects such as sculptures or rock engravings), and it is still widely used in contemporary works. Soluble salts are the main erosive agent in the built environment, and we review here comparative studies that subject the same rock type to testing with different salt solutions. The results mostly support the accepted notion of the major impact of sodium sulphate, although there are some exceptions. The effects of sodium chloride and calcium sulphate deserve specific discussion given field information on the relevance of these specific salts in the built environment. We relate the information collected to the issues of risk assessment (considering both geochemical conditions and salt effects) and conservation interventions (highlighting the interest of tests that do not produce damage to susceptible materials) and present some methodological suggestions to avoid a case study culture.The Lab2PT-Landscapes, Heritage and Territory laboratory—UIDB/04509/2020 is supported by the Portuguese FCT—“Fundação para a Ciência e a Tecnologia”. The authors also gratefully acknowledge the support of the CERENA (funded by a strategic project of the FCTUIDB/04028/2020) and the LAMPIST of the DECivil, Instituto Superior Técnico, University of Lisbon, Portugal. The University Institute of Geology of the University of A Coruña (Spain) receives support from the Xunta de Galicia from the program “Consolidación y estructuración de unidades de investigación competitivas: Grupos de potencial de crecimiento” (ED431B 2018/47) and Redes de investigación (R2017/008)

    A human centred hybrid MAS and meta-heuristics based system for simultaneously supporting scheduling and plant layout adjustment

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    Manufacturing activities and production control are constantly growing. Despite this, it is necessary to improve the increasing variety of scheduling and layout adjustments for dynamic and flexible responses in volatile environments with disruptions or failures. Faced with the lack of realistic and practical manufacturing scenarios, this approach allows simulating and solving the problem of job shop scheduling on a production system by taking advantage of genetic algorithm and particle swarm optimization algorithm combined with the flexibility and robustness of a multi-agent system and dynamic rescheduling alternatives. Therefore, this hybrid decision support system intends to obtain optimized solutions and enable humans to interact with the system to properly adjust priorities or refine setups or solutions, in an interactive and user-friendly way. The system allows to evaluate the optimization performance of each one of the algorithms proposed, as well as to obtain decentralization in responsiveness and dynamic decisions for rescheduling due to the occurance of unexpected events.This work has been supported by FCT - Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019

    Engineering students and mathematics achievement: a portuguese case study

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    Mathematics is a discipline that appears on the syllabus of many courses, including courses in engineering, where it is essential to the formation of all future engineers, whatever their field of study and work. Despite that, engineering students tend to reveal difficulties with course units based on mathematics. The factors that influence learning mathematics have been the subject of study for several researchers around the world. Researchers attempt to identify variables that explain mathematics achievement, but fail to address university students. In this paper, an exploratory study based on engineering students of University of Minho, concerning their grades in statistics and numerical methods curricular units is presented. The aim of this study is to explore the mathematics achievement in the process of learning mathematical concepts. The preliminary results show that gender is an unexpected and significant factor.Fundação para a Ciência e a Tecnologia (FCT
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