Exact and Heuristic Approaches for Role Assignment Problem in Wireless Sensor Networks

The wireless sensor networks (WSN) can be considered as a special type of mobile ad-hoc network able to monitor the physical environment through small sensors. Such networks became viable due to the convergence of micro-electro-mechanical systems technology, wireless communication and digital electronics [1]. These small devices present memory, energy and transmission constraints; so, they must be used in a larg

Clinical symptom profile of hospitalized COVID-19 Brazilian patients according to SARS-CoV-2 variants

OBJECTIVES The aim of this study was to investigate the prevalence of the main symptoms in Brazilian coronavirus disease 2019 (COVID-19) patients hospitalized during 4 distinct waves, based on their infection with different severe acute respiratory disease coronavirus 2 (SARS-CoV-2) variants. METHODS This study included hospitalized patients who tested positive for SARS-CoV-2 during 15 weeks around the peak of each of 4 waves: W1, ancestral strain/B.1 lineage (May 31 to September 12, 2020); W2, Gamma/P.1 variant (January 31 to May 15, 2021); W3, Omicron variant (December 5, 2021 to March 19, 2022); and W4, BA.4/BA.5 subvariants (May 22 to September 3, 2022). Symptom data were extracted from the Brazilian Severe Acute Respiratory Syndrome Database. Relative risks were calculated, and an analysis of symptom networks was performed. RESULTS Patients who were hospitalized during the prevalence of the Gamma/P.1 variant demonstrated a higher risk, primarily for symptoms such as fatigue, abdominal pain, low oxygen saturation, and sore throat, than patients hospitalized during the first wave. Conversely, patients who were hospitalized during the predominance of the Omicron variant exhibited a lower relative risk, particularly for symptoms such as loss of smell, loss of taste, diarrhea, fever, respiratory distress, and dyspnea. Similar results were observed in COVID-19 patients who were hospitalized during the wave of the Omicron subvariants BA.4/BA.5. A symptom network analysis, conducted to explore co-occurrence patterns among different variants, revealed significant differential profiles across the 4 waves, with the most notable difference observed between the W2 and W4 networks. CONCLUSIONS Overall, the relative risks and patterns of symptom co-occurrence associated with different SARS-CoV-2 variants may reflect disease severity

On the analysis of mortality risk factors for hospitalized COVID-19 patients: A data-driven study using the major Brazilian database.

BackgroundBrazil became the epicenter of the COVID-19 epidemic in a brief period of a few months after the first officially registered case. The knowledge of the epidemiological/clinical profile and the risk factors of Brazilian COVID-19 patients can assist in the decision making of physicians in the implementation of early and most appropriate measures for poor prognosis patients. However, these reports are missing. Here we present a comprehensive study that addresses this demand.MethodsThis data-driven study was based on the Brazilian Ministry of Health Database (SIVEP-Gripe) regarding notified cases of hospitalized COVID-19 patients during the period from February 26th to August 10th, 2020. Demographic data, clinical symptoms, comorbidities and other additional information of patients were analyzed.ResultsThe hospitalization rate was higher for male gender (56.56%) and for older age patients of both sexes. Overall, the lethality rate was quite high (41.28%) among hospitalized patients, especially those over 60 years of age. Most prevalent symptoms were cough, dyspnoea, fever, low oxygen saturation and respiratory distress. Cardiac disease, diabetes, obesity, kidney disease, neurological disease, and pneumopathy were the most prevalent comorbidities. A high prevalence of hospitalized COVID-19 patients with cardiac disease (65.7%) and diabetes (53.55%) and with a high lethality rate of around 50% was observed. The intensive care unit (ICU) admission rate was 39.37% and of these 62.4% died. 24.4% of patients required invasive mechanical ventilation (IMV), with high mortality among them (82.98%). The main mortality risk predictors were older age and IMV requirement. In addition, socioeconomic conditions have been shown to significantly influence the disease outcome, regardless of age and comorbidities.ConclusionOur study provides a comprehensive overview of the hospitalized Brazilian COVID-19 patients profile and the mortality risk factors. The analysis also evidenced that the disease outcome is influenced by multiple factors, as unequally affects different segments of population

Uma metodologia heurística baseada em grasp, VND e VNS para a resiolução do problema de dimensionamento em redes IP.

O presente trabalho apresenta uma proposta de formulação e implementação de algoritmos baseados nas técnicas de otimização GRASP (Greed Randomized Search Procedure), VND (Variable Neighborhood Descent) e VNS (Variable Neighborhood Search) para satisfazer a nova geração da Internet, que implementa Qualidade de Serviço e Engenharia de Tráfego. Este contexto surgiu da crescente expansão da Internet e da necessidade de satisfazer a novos requisitos impostos por aplicações mais complexas, tais como transmissões em tempo real, exigindo que caminhos explícitos entre um nó de entrada da rede e um ou mais nós de saída sejam computados. Esta tarefa é também chamada de dimensionamento da rede. Resultados computacionais são apresentados, comprovando que é possível prover uma melhora no dimensionamento da rede através das técnicas propostas.This work presents a proposal of formulation and implementation of algorithms based on GRASP (Greed Randomized Search Procedure), VND (Variable Neighborhood Descent) and VNS (Variable Neighborhood Search) optimization techniques to satisfy the new Internet generation, which implements Quality of Service (QoS) and Traffic Engineering. Because of the Internet expansion and the necessity to support new requirements demanded by more complex applications, such as real time transmissions, this new context appeared requiring that paths between the ingress and egress nodes are determined. This task is also called network dimensioning. Computational results are presented, proving that it is possible to provide an improvement in the network dimensioning, through the proposed techniques