Iterated local search for the placement of wildland fire suppression resources

We consider the problem of, given a landscape represented by a gridded network and a fire ignition location, deciding where to locate the available fire suppression resources to minimise the burned area and the number of deployed resources as a secondary objective. We assume an estimate of the fire propagation times between adjacent nodes and use the minimum travel time principle to model the fire propagation at a landscape-level. The effect of locating a resource in a node is that it becomes protected and the fire propagation to its unburned adjacent nodes is delayed. Therefore, the problem is to identify the most promising nodes to locate the resources, which is solved by a novel iterated local search (ILS) metaheuristic. A mixed integer programming (MIP) model from the literature is used to validate the proposed method in 32 grid networks with sizes 6x6, 10x10, 20x20 and 30x30, with two different number of fire suppression resources (64 problems). Our ILS produced optimal solutions in 40 cases out of 41 known optimal lower bounds. The proposed method’s effectiveness is also due to its short computing times and small coefficients of variation of the objective function values. We also provide a categorised literature review on fire suppression deterministic optimisation models, from which we conclude that approximate collaborative approaches seldom have been applied in the past and, according to the results obtained, can successfully address the complexity of fire suppression, reaching good quality solutions even for large scale instances.This work has been supported by FCT - Fundação para a Ciência e Tecnologia within the R&D Units Project Scope UIDB/00319/2020 and within project PCIF/GRF/0141/2019 “O3F - An Optimization Framework to Reduce Forest Fire”. This paper has greatly benefit ted from the insights and suggestions of anonymous reviewers on an earlier version of the pape

Strategies for scheduling jobs in an identical parallel machine production environment

CAPESCNP

Hepatotoxicity In Hiv-infected Children And Adolescents On Antiretroviral Therapy.

Adverse drug reactions are a significant problem in patients on antiretroviral therapy (ART). We determined liver enzyme elevation frequencies in HIV-infected children and adolescents receiving ART, and their association with risk factors. Cross-sectional study, at the Pediatrics Immunodeficiency Division, University Hospital, Universidade Estadual de Campinas. Medical records of 152 children and adolescents (54.6% male; median age 7.48 years) were analyzed, with a mean of 2.6 liver enzyme determinations per patient. Clinically, patients were classified in categories N (6), A (29), B (78) and C (39). Serum levels of aspartate aminotransferase and alanine aminotransferase were evaluated. Hepatotoxicity was scored as grade 1 (1.1-4.9 times upper limit of normality, ULN), grade 2 (5.0-9.9 times ULN), grade 3 (10.0-15.0 times ULN) and grade 4 (> 15.0 times ULN). To assess hepatotoxicity risk factors, odds ratios (OR) and adjusted odds ratios (aOR) for age, gender, TCD4+ cell count, viral load and medication usage were calculated. We observed grade 1 hepatotoxicity in 19.7 % (30/152) patients. No cases of grade 2, 3 or 4 were detected. There was a significant association between hepatotoxicity and use of sulfonamides (OR, 3.61; 95% confidence interval (CI), 1.50-8.70; aOR, 3.58; 95% CI, 1.44-8.85) and antituberculous agents (OR, 9.23; 95% CI, 1.60-53.08; aOR, 9.05; 95% CI, 1.48-55.25). No toxicity was associated with ART. One fifth of patients experienced mild hepatotoxicity, attributed to antituberculous agents and sulfonamides. Our results suggest that ART was well tolerated.125205-

The European Reference Genome Atlas: piloting a decentralised approach to equitable biodiversity genomics.

ABSTRACT: A global genome database of all of Earth’s species diversity could be a treasure trove of scientific discoveries. However, regardless of the major advances in genome sequencing technologies, only a tiny fraction of species have genomic information available. To contribute to a more complete planetary genomic database, scientists and institutions across the world have united under the Earth BioGenome Project (EBP), which plans to sequence and assemble high-quality reference genomes for all ∼1.5 million recognized eukaryotic species through a stepwise phased approach. As the initiative transitions into Phase II, where 150,000 species are to be sequenced in just four years, worldwide participation in the project will be fundamental to success. As the European node of the EBP, the European Reference Genome Atlas (ERGA) seeks to implement a new decentralised, accessible, equitable and inclusive model for producing high-quality reference genomes, which will inform EBP as it scales. To embark on this mission, ERGA launched a Pilot Project to establish a network across Europe to develop and test the first infrastructure of its kind for the coordinated and distributed reference genome production on 98 European eukaryotic species from sample providers across 33 European countries. Here we outline the process and challenges faced during the development of a pilot infrastructure for the production of reference genome resources, and explore the effectiveness of this approach in terms of high-quality reference genome production, considering also equity and inclusion. The outcomes and lessons learned during this pilot provide a solid foundation for ERGA while offering key learnings to other transnational and national genomic resource projects.info:eu-repo/semantics/publishedVersio

The genetic diversity, phylogeography and morphology of Elphidiidae (Foraminifera) in the Northeast Atlantic

Genetic characterisation (SSU rRNA genotyping) and Scanning ElectronMicroscope (SEM) imaging of individualtests were used in tandem to determine the modern species richness of the foraminiferal family Elphidiidae(Elphidium, Haynesina and related genera) across the Northeast Atlantic shelf biomes. Specimens were collectedat 25 locations fromthe High Arctic to Iberia, and a total of 1013 individual specimenswere successfully SEMimagedand genotyped. Phylogenetic analyses were carried out in combination with 28 other elphidiid sequencesfrom GenBank and seventeen distinct elphidiid genetic types were identified within the sample set, sevenbeing sequenced for the first time. Genetic types cluster into sevenmain cladeswhich largely represent their generalmorphologicalcharacter. Differences between genetic types at the genetic, morphological and biogeographiclevels are indicative of species level distinction. Their biogeographic distributions, in combination with elphidiidSSU sequences from GenBank and high resolution images from the literature show that each of them exhibitsspecies-specific rather than clade-specific biogeographies. Due to taxonomic uncertainty and divergent taxonomicconcepts between schools, we believe that morphospecies names should not be placed onto molecularphylogenies unless both the morphology and genetic type have been linked to the formally named holotype,or equivalent. Based on strictmorphological criteria,we advocate using only a three-stage approach to taxonomyfor practical application in micropalaeontological studies. It comprises genotyping, the production of a formalmorphological description of the SEM images associated with the genetic type and then the allocation of themost appropriate taxonomic name by comparison with the formal type description. Using this approach, wewere able to apply taxonomic names to fifteen genetic types. One of the remaining two may be potentially cryptic,and one is undescribed in the literature. In general, the phylogeographic distribution is in agreement with ourknowledge of the ecology and biogeographical distribution of the corresponding morphospecies, highlighting thegenerally robust taxonomic framework of the Elphidiidae in time and space

Sem título em inglês

A Hidrovia Tietê-Paraná é um complexo hidroviário que atravessa a região sudeste do Brasil e constitui um meio de transporte alternativo ainda pouco explorado, que interliga 5 grandes estados brasileiros, além de ser um elo de ligação com os países do MERCOSUL. O gabarito da hidrovia limita barcaças a dimensões principais de 60m x 11m x 2,5m, mas que acopladas formam comboios com capacidade de até 4500t. Estas embarcações podem transportar cargas de granel sólido (commodities agrícolas) e de granel líquido (combustíveis) no longo curso, areia e cana-de-açúcar em curtas distâncias, sendo que experiências com carga geral também foram feitas. Devido ao fato dos centros produtores e dos centros consumidores estarem distantes da hidrovia, a eficiência do transporte hidroviário é altamente dependente da eficiência do sistema logístico em que está inserido. Desta forma, tanto os sistemas de transporte nas pontas de origem e destino (rodoviário e ferroviário), como também a armazenagem nos terminais intermodais devem estar operando de maneira eficaz e balanceada para tornar este sistema competitivo. O objetivo desta pesquisa é dar uma resposta eficiente e realista ao problema de dimensionar um sistema de transporte utilizando modais combinados. Desta forma, dado uma origem e um destino, um tipo de carga, sua demanda mensal, os modais de transporte utilizados, busca-se dimensionar cada parte deste sistema intermodal, fornecendo como resposta a configuração de frota de caminhões e o número de viagens necessárias, o número de composições ferroviárias e a frequência de requisição das mesmas, a frota de embarcações fluviais e a capacidade dos terminais de carga. O dimensionamento é focado na solução que atende à demanda a um mínimo custo. Desta forma, os aspectos econômicos de cada operação também são considerados. Para resolver este problema complexo, utilizou-se a técnica de simulação probabilística, pois a mesma permite modelar com maior precisão a interação entre os diversos subsistemas, além de poder representar os fenômenos aleatórios presentes. A simulação também é uma boa ferramenta para lidar com os congestionamentos observados na passagem em eclusas, canais e na utilização de berços dos terminais. O sistema consiste de um módulo de entrada de dados, no qual o usuário define o cenário padrão que deverá ser simulado. O modelo computacional foi desenvolvido na linguagem de simulação ARENA, o qual conta com uma rica interface gráfica, módulos de análise de dados (input and output analyser), ferramentas para construção de templates personalizados, programação complementada por recursos do Visual Basic for Applications e um gerenciador de cenários que permite programar diversas rodadas consecutivas do modelo. O modelo foi aplicado à Hidrovia Tietê-Paraná e aos modais a ela associados, e permitiu dimensionar um sistema intermodal com menor custo total do que o transporte de grãos exclusivamente rodoviário.Tietê-Paraná Waterway is a complex inland navigation system that crosses the southeast area of Brazil, and it is an alternative mean of transportation still not very explored, that connects 5 great Brazilian states, besides being a connection link with the countries of MERCOSUL. The waterway dimensions limits the barges to 60m x 11m x 2,5m, but when coupled, form convoys with capacity of up to 4500 tons. These vessels transport dry bulk (agricultural commodities) and wet bulk (fuels) in the long course, and sand and sugar-cane in short distances. Due to the fact of the producing centers and of the consuming centers are distant from the waterway, the efficiency of the waterway transportation is highly dependent of the efficiency of the whole logistics system. Therefore the transport systems in the origin and destiny points (road and rail transport), as well as the storage in the intermodal terminals should be designed and operated in an effective and balanced way to turn a competitive system. The objective of this current research is to give a fast and realistic answer to the design problem of a transportation system using different combined modals. Therefore, given an origin and a destiny, a cargo type, its monthly demand and the modals of transportation, the model would design each part of this intermodal system, giving as a response the configuration of the fleet of trucks and the number of necessary trips, the number of rail compositions and their frequency of requisition, the fleet of vessels and the storage capacity of the terminals. The system design is focused in the solution that attends the monthly demand at a minimum cost. Therefore the economical aspects of each operation are also considered.To solve this complex problem, the technique of probabilistic simulation was used, because it allows to model with larger precision the interaction among the several subsystems, besides allowing to represent the randomness of the system. Simulation is also an appropriate tool to represent the traffic jams in the locks and in the passage through the channels and also to lead with the occupation of terminal\'s berths. The system consists of a module of data entrance, in which the user defines the standard scenario that should be simulated. The computational model was developed using the simulation language ARENA, that has a rich graphic interface, modules of data analysis (input and output analyzer), tools for construction of customized templates, programming complemented by resources of Visual Basic for Applications and a scenario manager that allows to program several serial runs of the model

Sem título em inglês

A Hidrovia Tietê-Paraná é um complexo hidroviário que atravessa a região sudeste do Brasil e constitui um meio de transporte alternativo ainda pouco explorado, que interliga 5 grandes estados brasileiros, além de ser um elo de ligação com os países do MERCOSUL. O gabarito da hidrovia limita barcaças a dimensões principais de 60m x 11m x 2,5m, mas que acopladas formam comboios com capacidade de até 4500t. Estas embarcações podem transportar cargas de granel sólido (commodities agrícolas) e de granel líquido (combustíveis) no longo curso, areia e cana-de-açúcar em curtas distâncias, sendo que experiências com carga geral também foram feitas. Devido ao fato dos centros produtores e dos centros consumidores estarem distantes da hidrovia, a eficiência do transporte hidroviário é altamente dependente da eficiência do sistema logístico em que está inserido. Desta forma, tanto os sistemas de transporte nas pontas de origem e destino (rodoviário e ferroviário), como também a armazenagem nos terminais intermodais devem estar operando de maneira eficaz e balanceada para tornar este sistema competitivo. O objetivo desta pesquisa é dar uma resposta eficiente e realista ao problema de dimensionar um sistema de transporte utilizando modais combinados. Desta forma, dado uma origem e um destino, um tipo de carga, sua demanda mensal, os modais de transporte utilizados, busca-se dimensionar cada parte deste sistema intermodal, fornecendo como resposta a configuração de frota de caminhões e o número de viagens necessárias, o número de composições ferroviárias e a frequência de requisição das mesmas, a frota de embarcações fluviais e a capacidade dos terminais de carga. O dimensionamento é focado na solução que atende à demanda a um mínimo custo. Desta forma, os aspectos econômicos de cada operação também são considerados. Para resolver este problema complexo, utilizou-se a técnica de simulação probabilística, pois a mesma permite modelar com maior precisão a interação entre os diversos subsistemas, além de poder representar os fenômenos aleatórios presentes. A simulação também é uma boa ferramenta para lidar com os congestionamentos observados na passagem em eclusas, canais e na utilização de berços dos terminais. O sistema consiste de um módulo de entrada de dados, no qual o usuário define o cenário padrão que deverá ser simulado. O modelo computacional foi desenvolvido na linguagem de simulação ARENA, o qual conta com uma rica interface gráfica, módulos de análise de dados (input and output analyser), ferramentas para construção de templates personalizados, programação complementada por recursos do Visual Basic for Applications e um gerenciador de cenários que permite programar diversas rodadas consecutivas do modelo. O modelo foi aplicado à Hidrovia Tietê-Paraná e aos modais a ela associados, e permitiu dimensionar um sistema intermodal com menor custo total do que o transporte de grãos exclusivamente rodoviário.Tietê-Paraná Waterway is a complex inland navigation system that crosses the southeast area of Brazil, and it is an alternative mean of transportation still not very explored, that connects 5 great Brazilian states, besides being a connection link with the countries of MERCOSUL. The waterway dimensions limits the barges to 60m x 11m x 2,5m, but when coupled, form convoys with capacity of up to 4500 tons. These vessels transport dry bulk (agricultural commodities) and wet bulk (fuels) in the long course, and sand and sugar-cane in short distances. Due to the fact of the producing centers and of the consuming centers are distant from the waterway, the efficiency of the waterway transportation is highly dependent of the efficiency of the whole logistics system. Therefore the transport systems in the origin and destiny points (road and rail transport), as well as the storage in the intermodal terminals should be designed and operated in an effective and balanced way to turn a competitive system. The objective of this current research is to give a fast and realistic answer to the design problem of a transportation system using different combined modals. Therefore, given an origin and a destiny, a cargo type, its monthly demand and the modals of transportation, the model would design each part of this intermodal system, giving as a response the configuration of the fleet of trucks and the number of necessary trips, the number of rail compositions and their frequency of requisition, the fleet of vessels and the storage capacity of the terminals. The system design is focused in the solution that attends the monthly demand at a minimum cost. Therefore the economical aspects of each operation are also considered.To solve this complex problem, the technique of probabilistic simulation was used, because it allows to model with larger precision the interaction among the several subsystems, besides allowing to represent the randomness of the system. Simulation is also an appropriate tool to represent the traffic jams in the locks and in the passage through the channels and also to lead with the occupation of terminal\'s berths. The system consists of a module of data entrance, in which the user defines the standard scenario that should be simulated. The computational model was developed using the simulation language ARENA, that has a rich graphic interface, modules of data analysis (input and output analyzer), tools for construction of customized templates, programming complemented by resources of Visual Basic for Applications and a scenario manager that allows to program several serial runs of the model

Fleet scheduling subject to multiple vessels for the each task in an offshore operation.

A presente pesquisa aborda um problema de roteirização e programação de veículos incorporando uma nova restrição operacional: a requisição simultânea de múltiplos veículos para atendimento da demanda. Trata-se de uma característica encontrada em operações de apoio à exploração de petróleo \"offshore\", em que mais de uma embarcação é requerida para executar tarefas de reboque e lançamento de linhas de ancoragem. Esta imposição, somada às restrições de janela de tempo, precedência entre tarefas, autonomia das embarcações e atendimento integral da demanda, configuram este problema. A programação é orientada pela minimização dos custos variáveis da operação e dos custos associados ao nível de serviço no atendimento. Este problema é uma variação do problema clássico de roteirização e programação de veículos com janela de tempo, de classe NP-Difícil. Nesta pesquisa, propõe-se modelar e resolver o problema em escala real por meio do algoritmo \"branch and cut\" acoplado às heurísticas de busca em vizinhança \"local branching\" e \"variable neighborhood search\". Para gerar as soluções iniciais será empregado o método \"feasibility pump\" e uma heurística construtiva.This research focuses a fleet scheduling problem with new operational constraints: each task requiring multiple types of vehicles simultaneously. This kind of operation occurs in offshore exploitation and production sites, when more than one vessel is needed to accomplish the tugging and mooring of oil platforms. Other constraints are maintained such as time windows, precedence between tasks, route duration and the demand attendance. The solution schedules are cost oriented, which encompasses the routing variable costs and the customer service costs. This is a variation of the classical fleet routing and scheduling, which is an NP-Hard problem. This research aims to solve the real scale problem through a combined use of branch and cut strategy with local search algorithms such as local branching and variable neighborhood search. An efficient heuristic rule will be used in order to generate initial solutions using the feasibility pump method

Column Generation for a Multitrip Vehicle Routing Problem with Time Windows, Driver Work Hours, and Heterogeneous Fleet

This study addresses a vehicle routing problem with time windows, accessibility restrictions on customers, and a fleet that is heterogeneous with regard to capacity and average speed. A vehicle can perform multiple routes per day, all starting and ending at a single depot, and it is assigned to a single driver whose total work hours are limited. A column generation algorithm is proposed. The column generation pricing subproblem requires a specific elementary shortest path problem with resource constraints algorithm to address the possibility for each vehicle performing multiple routes per day and to address the need to set the workday’s start time within the planning horizon. A constructive heuristic and a metaheuristic based on tabu search are also developed to find good solutions

Application of Multi-Attribute Value Theory to Improve Cargo Delivery Planning in Disaster Aftermath

Although many Operational Research models have been applied to disaster response operations, few researchers aim at revealing Decision Makers’ goals or measuring their trade-offs. This article uses a holistic Multi-Criteria Decision Analysis (MCDA) method to elucidate what objectives to pursue and to create appropriate strategies for planning vital items delivery to victims. We propose a framework for applying a Multi-Attribute Value Theory technique and test it with a humanitarian Decision Maker. The resulting mathematical model can be used to evaluate guidelines that make on-field decisions easier, improving (or at least not compromising) their outcomes. Our contribution to the MCDA field includes the documentation of an alternative generation methodology