Serial batch processing machine scheduling: a cement industry case study

Dissertação de mestrado em Engenharia de SistemasThis work arises in the Cement Industry in the process of scheduling the clients to the warehouse and assignment to docking bays. The goal is to solve the scheduling and assignment problem, to improve both company’s service levels and the efficiency of its resources. After the real problem analysis, it was possible to conclude that it could be solved as a batching machine scheduling problem, where the jobs are the clients to be schedule, and the machine is the warehouse. The problem can be described as max 1 | rj,s-batch | Cmax . A Mixed Integer Linear Programming (MILP) model was proposed. However, as the number of jobs increased it started having computational difficulties. To overcome the problems of the MILP model two heuristics were proposed. The first one is a Constructive Algorithm (CA) that creates a first solution for the problem. The second heuristic is a metaheuristic algorithm, based on Simulated Annealing procedures, that starts with the initial solution of the CA and through three possible moves starts constructing the neighboring solutions space. After constructing the neighboring solutions space, it returns the best solution found. The computational tests proved that both the MILP model and the heuristics can ensure both feasible and optimum solutions. However, the MILP model consumes more computational resources. For some larger instances and giving a maximum limit of computational time of 8 hours, the MILP model cannot reach the optimality, nor the good results obtained by the heuristics, for those larger instances. The machine scheduling is a good approach for scheduling the trucks to the warehouse. Since it is also an innovative approach for the problem, considering the literature studied, maybe this work will inspire others to work on this idea or, at least, serve as a basis for future researches.Este trabalho tem como cenário a Indústria Cimenteira no processo de agendamento de clientes para atendimento no armazém e atribuição de pontos de carga. O objetivo é resolver o problema de agendamento visando otimizar tanto os níveis de serviço da empresa bem como a eficiência dos seus recursos. Depois da análise detalhada do problema real foi possível concluir que este podia ser resolvido como um problema de processamento em lotes em máquina única, onde as tarefas a agendar seriam os clientes e a máquina o armazém. O problema pode então ser descrito como 1 | rj,s-batch | Cmax . Um modelo de Programação Linear Inteira Mista (PLIM) foi proposto. Contudo, à medida que o número de tarefas aumentava, o modelo começava a ter dificuldades computacionais na obtenção de solução ótima. Para ultrapassar essas dificuldades, foram desenhadas e propostas duas heurísticas. A primeira é um Algoritmo Construtivo (AC) capaz de retornar uma solução inicial. A segunda, uma meta-heurística, baseada na abordagem do Simulated Annealing, que trabalha a solução inicial gerada pelo AC, através de três movimentos possíveis, e gera uma vizinhança de soluções. Depois, procura e retorna a melhor solução possível dessa vizinhança. Os testes computacionais provaram que tanto o modelo de PLIM como as heurísticas são capazes de retornar tanto soluções possíveis como ótimas. Contudo, o modelo de PLIM consome muitos mais recursos computacionais do que as heurísticas. Para instâncias de tamanho superior, dado um tempo de computação máximo de 8 horas, o PLIM, não conseguindo atingir a solução ótima, nem sequer consegue atingir soluções tão boas como as das heurísticas. A abordagem de agendamento em máquinas, utilizada neste trabalho, mostrou-se ser uma boa abordagem para o agendamento de clientes no armazém. Para além disso, esta é uma abordagem inovadora, tendo em conta a literatura estudada, e, talvez possa inspirar outros autores a trabalhar nesta ideia ou então servir de base para pesquisas futuras

Integer programming model for ship loading management: a case study from cement industry

Industries only survive in the modern business world if they are prepared to improve processes whenever it is necessary. Therefore, companies need to adapt and/or modify processes to improve the level of service and reduce needless costs. In this article the logistics problem of planning a ship load operation of a Portuguese cement company is addressed. The objective is to determine the best way to transport the bagged cement from the warehouse to a ship reducing costs and optimizing forklifts operations. A mathematical programming model is proposed showing this methodology as a powerful tool to provide effective support to a more intelligent decision process.- (undefined

HIV prevalence among men who have sex with men in Brazil : results of the 2nd national survey using respondent-driven sampling

This paper reports human immuno-deficiency virus (HIV) prevalence in the 2nd National Biological and Behavioral Surveillance Survey (BBSS) among men who have sex with men (MSM) in 12 cities in Brazil using respondent-driven sampling (RDS). Following formative research, RDS was applied in 12 cities in the 5 macroregions of Brazil between June and December 2016 to recruit MSM for BBSS. The target sample size was 350 per city. Five to 6 seeds were initially selected to initiate recruitment and coupons and interviews were managed online. On-site rapid testing was used for HIV screening, and confirmed by a 2nd test. Participants were weighted using Gile estimator. Data from all 12 cities were merged and analyzed with Stata 14.0 complex survey data analysis tools in which each city was treated as its own strata. Missing data for those who did not test were imputed HIV+ if they reported testing positive before and were taking antiretroviral therapy. A total of 4176 men were recruited in the 12 cities. The average time to completion was 10.2 weeks. The longest chain length varied from 8 to 21 waves. The sample size was achieved in all but 2 cities. A total of 3958 of the 4176 respondents agreed to test for HIV (90.2%). For results without imputation, 17.5% (95%CI: 14.7–20.7) of our sample was HIV positive. With imputation, 18.4% (95%CI: 15.4–21.7) were seropositive. HIV prevalence increased beyond expectations from the results of the 2009 survey (12.1%; 95%CI: 10.0–14.5) to 18.4%; CI95%: 15.4 to 21.7 in 2016. This increase accompanies Brazil’s focus on the treatment to prevention strategy, and a decrease in support for community-based organizations and community prevention programs

Coinfection with Different Trypanosoma cruzi Strains Interferes with the Host Immune Response to Infection

A century after the discovery of Trypanosoma cruzi in a child living in Lassance, Minas Gerais, Brazil in 1909, many uncertainties remain with respect to factors determining the pathogenesis of Chagas disease (CD). Herein, we simultaneously investigate the contribution of both host and parasite factors during acute phase of infection in BALB/c mice infected with the JG and/or CL Brener T. cruzi strains. JG single infected mice presented reduced parasitemia and heart parasitism, no mortality, levels of pro-inflammatory mediators (TNF-α, CCL2, IL-6 and IFN-γ) similar to those found among naïve animals and no clinical manifestations of disease. On the other hand, CL Brener single infected mice presented higher parasitemia and heart parasitism, as well as an increased systemic release of pro-inflammatory mediators and higher mortality probably due to a toxic shock-like systemic inflammatory response. Interestingly, coinfection with JG and CL Brener strains resulted in intermediate parasitemia, heart parasitism and mortality. This was accompanied by an increase in the systemic release of IL-10 with a parallel increase in the number of MAC-3+ and CD4+ T spleen cells expressing IL-10. Therefore, the endogenous production of IL-10 elicited by coinfection seems to be crucial to counterregulate the potentially lethal effects triggered by systemic release of pro-inflammatory mediators induced by CL Brener single infection. In conclusion, our results suggest that the composition of the infecting parasite population plays a role in the host response to T. cruzi in determining the severity of the disease in experimentally infected BALB/c mice. The combination of JG and CL Brener was able to trigger both protective inflammatory immunity and regulatory immune mechanisms that attenuate damage caused by inflammation and disease severity in BALB/c mice

SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal

Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementation of measures could have minimized the number of introductions and subsequent virus expansion in Portugal. This study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.We gratefully acknowledge to Sara Hill and Nuno Faria (University of Oxford) and Joshua Quick and Nick Loman (University of Birmingham) for kindly providing us with the initial sets of Artic Network primers for NGS; Rafael Mamede (MRamirez team, IMM, Lisbon) for developing and sharing a bioinformatics script for sequence curation (https://github.com/rfm-targa/BioinfUtils); Philippe Lemey (KU Leuven) for providing guidance on the implementation of the phylodynamic models; Joshua L. Cherry (National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health) for providing guidance with the subsampling strategies; and all authors, originating and submitting laboratories who have contributed genome data on GISAID (https://www.gisaid.org/) on which part of this research is based. The opinions expressed in this article are those of the authors and do not reflect the view of the National Institutes of Health, the Department of Health and Human Services, or the United States government. This study is co-funded by Fundação para a Ciência e Tecnologia and Agência de Investigação Clínica e Inovação Biomédica (234_596874175) on behalf of the Research 4 COVID-19 call. Some infrastructural resources used in this study come from the GenomePT project (POCI-01-0145-FEDER-022184), supported by COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio

SABER TREINAR A SI MESMO: PORQUE E COMO DEVEMOS ENSINAR TREINAMENTO NAS AULAS DE EDUCAÇÃO FÍSICA?

O texto apresenta argumentações cientificas sobre o treino corporal na escola a partir de uma experiência concreta na Escola Municipal Teodoro Sampaio, Salvador, Bahia, Brasil

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio