ABSTRACT BACKGROUND: The fragility of healthcare systems worldwide had not been exposed by any pandemic until now. The lack of integrated methods for bed capacity planning compromises the effectiveness of public and private hospitals’ services. OBJECTIVES: To estimate the impact of the COVID-19 pandemic on the provision of intensive care unit and clinical beds for Brazilian states, using an integrated model. DESIGN AND SETTING: Experimental study applying healthcare informatics to data on COVID-19 cases from the official electronic platform of the Brazilian Ministry of Health. METHODS: A predictive model based on the historical records of Brazilian states was developed to estimate the need for hospital beds during the COVID-19 pandemic. RESULTS: The proposed model projected in advance that there was a lack of 22,771 hospital beds for Brazilian states, of which 38.95% were ICU beds, and 61.05% were clinical beds. CONCLUSIONS: The proposed approach provides valuable information to help hospital managers anticipate actions for improving healthcare system capacity.

ABSTRACT BACKGROUND: Since February 2020, data on the clinical features of patients infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and their clinical evolution have been gathered and intensively discussed, especially in countries with dramatic dissemination of this disease. OBJECTIVE: To assess the clinical features of Brazilian patients with SARS-CoV-2 and analyze its local epidemiological features. DESIGN AND SETTING: Observational retrospective study conducted using data from an official electronic platform for recording confirmed SARS-CoV-2 cases. METHODS: We extracted data from patients based in the state of Pernambuco who were registered on the platform of the Center for Strategic Health Surveillance Information, between February 26 and May 25, 2020. Clinical signs/symptoms, case evolution over time, distribution of confirmed, recovered and fatal cases and relationship between age group and gender were assessed. RESULTS: We included 28,854 patients who were positive for SARS-CoV-2 (56.13% females), of median age 44.18 years. SARS-CoV-2 infection was most frequent among adults aged 30-39 years. Among cases that progressed to death, the most frequent age range was 70-79 years. Overall, the mortality rate in the cohort was 8.06%; recovery rate, 30.7%; and hospital admission rate (up to the end of follow-up), 17.3%. The average length of time between symptom onset and death was 10.3 days. The most commonly reported symptoms were coughing (42.39%), fever (38.03%) and dyspnea/respiratory distress with oxygen saturation < 95% (30.98%). CONCLUSION: Coughing, fever and dyspnea/respiratory distress with oxygen saturation < 95% were the commonest symptoms. The case-fatality rate was 8.06% and the hospitalization rate, 17.3%.

Abstract Paper aims To set the locations of new medical centers to meet the population’s secondary care needs, the additional number of specialists, equipment, and an installation sequence at municipalities. Originality We developed descriptive cost functions models and adopted aggregate data from official sources to set parameters of an integrated MILP model. Research method A case study at the Brazilian state of Minas Gerais. Main findings For every scenario, the recommended locations set centers dispersed over the state area, in cities with the minimum required infrastructure. We also propose a scenario of secondary care network re-design and demonstrate the reduced cost of such a strategy. Implications for theory and practice To automate the decision process, we developed a web-based system, providing flexibility and scientific-based results. Finally, we propose a sequence for installing 43 new medical centers and improving the capacity of 27 existing infrastructure based on equality principles.

No presente trabalho, realizou-se uma análise comparativa das metodologias utilizadas para o despacho de caminhões em minas a céu aberto. Comparações entre essas metodologias contam com poucos trabalhos publicados na literatura. Metodologias baseadas em programação linear e programação dinâmica e em heurística foram implementadas. Essas metodologias constituem as bases dos algoritmos de alguns dos sistemas de despacho comercializados no Brasil. Foi desenvolvido um modelo de simulação, a fim de se reproduzir o comportamento das operações de lavra de forma a avaliar o impacto das decisões de despacho em cada uma das metodologias estudadas. Os resultados obtidos mostraram o desempenho dos algoritmos, utilizando-se essas metodologias sob diferentes condições em minas a céu aberto. Porém não se pode, através dos resultados obtidos, concluir pela superioridade de uma delas.

In the present study a comparative analysis of the methodologies used to dispatch trucks in open pit mines has been carried out. There is a lack of studies comparing these methodologies in literature. Methodology based on linear and dynamic programming, as well as a heuristics-based methodology, have been implemented. These methodologies serve as the basis of algorithms used in some of the dispatch systems sold in Brazil. A simulation model was developed to reproduce the behavior of mining operations in order to evaluate the impact of dispatch decisions in each of the methodologies studied. Results show the performance of algorithms that have used these methodologies under different conditions in open pit mining. However, from results obtained in the present study, it is not possible, to state the superiority of any of them.

In this work, a mixed integer nonlinear programming model combining direct service links, demand uncertainty and congestion effects is proposed. This model is efficiently solved by Generalized Benders Decomposition, for instances of moderate sizes and reasonable number of scenarios. The deployed algorithms are further used for re-designing the Brazilian air transportation network, enabling the analysis of future demand scenarios and providing decision support about the optimal investment policy for Brazil.

O aumento da economia global, a concorrência e a tecnologia exigem cada vez mais agilidade e flexibilidade das organizações. Na siderurgia isso não é diferente, apesar de seus processos requererem grandes escalas e conseqüente elevação dos tempos de lead time. A manutenção de estoques, nesse contexto, se torna imprescindível. Este trabalho apresenta uma contribuição para o processo de tomada de decisão para quantificação de estoques em uma empresa de trefilação de arames. Um modelo matemático foi elaborado para auxiliar as políticas de aquisição e manutenção de estoques de cada item. A empresa forneceu informações chave para o modelo: vendas agregadas de produtos acabados; demanda histórica de insumos; histórico de suprimentos; desempenho de fornecedores e estratégia de compra para o período. Como o sistema envolve variáveis estocásticas, fez-se necessário a determinação dos níveis de estoque de segurança para evitar rupturas na produção e no fornecimento de produto aos clientes.

The increase of the global economy, the market competition and the technology demand more flexible and faster organizations. Despite the great production volume and its consequent increase of the lead time, the metallurgy industry is not out of this game. In this context, a good supply inventory policy may be a powerful tool. The article presents a contribution for the inventory decision process in a wire drawing industry. A descriptive mathematical model was built to support the supply order process of each product. The company supplied the key information of the model: aggregated sales of final products; forecast sales; supply items historical series; supplier’s performance and order’s strategy for the period. As the system involves stochastic variables, it was defined safety stocks to avoid production interruption and final products delivery interruption.

Esse trabalho desenvolve um modelo de programação linear por metas (goal programming) aplicado ao planejamento de produção em mineração. O objetivo é determinar o ritmo de lavra de cada frente, considerando a alocação de equipamentos de carga e transporte, de modo a fornecer à usina de beneficiamento uma alimentação adequada. Como cada frente possui características de qualidade diferentes, o ritmo de lavra deve ser realizado de forma proporcional, sendo limitado pela capacidade de produção dos equipamentos de carga e transporte disponíveis na mina. A mistura do minério proveniente de cada frente deve gerar uma alimentação que atenda as metas de qualidade e produção conforme as especificações preestabelecidas. Nesse trabalho, foi adotado o sistema de alocação estática de caminhões, por ser geralmente utilizado em minerações de pequeno e médio porte, devido à simplificação das operações e ao alto custo de implantação de um sistema de despacho eletrônico de caminhões. O modelo de programação matemática desenvolvido foi implementado no software de otimização LINGO 7.0 interfaceando com planilhas do EXCEL 2000, proporcionando, dessa forma, uma melhor interação entre o usuário e o aplicativo. O modelo foi validado usando uma instância-teste disponível na literatura, acrescida de metas de produção e qualidade.

This paper develops a goal programming model applied to mining production planning. The objective is to determine the run of each working bench, considering the allocation of load and haulage equipment, in order to supply the processing plant with an appropriate feeding. As each working bench holds different characteristics of quality, the run must be accomplished in a proportional way, being limited by the production capacity of the load and haulage equipment available in the mine. The blending of ore from each working bench should generate a feeding considering quality and production goals according to the given specifications. In this paper the truck static allocation system was adopted for being generally used by small and medium mines, due to the simplification of the operations and at the high cost of implantation of a truck dispatching system. The mathematical programming model was implemented using the optimization software LINGO 7.0 in conjunction with EXCEL 2000 spreadsheet, providing a better interaction between the user and the application. The model was validated using a test instance from the literature, added with production and quality goals.

Esse artigo descreve um conjunto de módulos, do Template Mineração 1.0, que foi desenvolvido para utilização no programa ARENA, visando a melhorar a modelagem e a simulação de operações de carregamento e transporte em minas a céu aberto. Os módulos representam atividades de lavra, tais como carga, descarga, deslocamento vazio e carregado dos caminhões, além de paradas para manutenção dos equipamentos. Os sistemas de alocação dinâmica de caminhões, atualmente presentes em boa parte das minas, também possuem um módulo específico. Através de testes realizados com dados reais, o Template mostrou-se de uso bastante amigável e apresentou resultados satisfatórios quando comparado com a operação real e com resultados de outro simulador.

This article describes a group of blocks of Template Mining 1.0, developed to be used with ARENA System. The objective is to improve modeling and simulation of open pit mining operations. The blocks represent the essential activities of open pit mining, like loading, unloading, loaded and unloaded haulage and equipment maintenance. The dynamic allocation system of trucks, nowadays used in the mining companies can also be represented. The Template has a friendly interface and it has been tested with real data. These tests have produced satisfactory results, which are similar to other simulation system.

O trabalho apresenta modelos matemáticos para resolução de problemas operacionais relacionados com o planejamento de lavra de minas a céu aberto. Os modelos se prestam à determinação do ritmo de lavra a ser implementado em cada frente de lavra, levando-se em consideração a qualidade do minério em cada frente, a relação estéril/minério desejada, a produção requerida, as características dos equipamentos de carga e transporte e as características operacionais da mina. Os modelos também consideram a possibilidade de alocação estática e dinâmica dos caminhões. No caso de alocação dinâmica, o modelo determina qual deve ser a produção de cada frente e aloca os equipamentos de carga às frentes escolhidas. No caso da alocação estática, além da alocação dos equipamentos de carga, o modelo também faz alocação dos caminhões às frentes.

This paper presents mathematical models to solve operational problems in open pit mining design such as ore blending and equipment assignment. The models determine the productivity of each working bench in one mine. They also consider the ore quality in order to make the blending, production goals, truck and shovel characteristics and availability, and support both static and dynamic allocation. The dynamic allocation model provides productivity and haulage equipment assignment. The static allocation model also provides the truck assignment.