João Gondim

Dr. João Gondim

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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 July 2023 in Mathematics
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Journal Article
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Raydonal OspinaRaydonal Ospina
Raydonal Ospina
JGJoão Gondim
João Gondim
Victor LeivaVictor Leiva
Victor Leiva
Cecília CastroCecília Castro
Cecília Castro
This comprehensive overview focuses on the issues presented by the pandemic due to COVID-19, understanding its spread and the wide-ranging effects of government-imposed restrictions. The overview examines the utility of autoregressive integrated moving average (ARIMA) models, which are often overlooked in pandemic forecasting due to perceived limitations in handling complex and dynamic scenarios. Our work applies ARIMA models to a case study using data from Recife, the capital of Pernambuco, Brazil, collected between March and September 2020. The research provides insights into the implications and adaptability of predictive methods in the context of a global pandemic. The findings highlight the ARIMA models’ strength in generating accurate short-term forecasts, crucial for an immediate response to slow down the disease’s rapid spread. Accurate and timely predictions serve as the basis for evidence-based public health strategies and interventions, greatly assisting in pandemic management. Our model selection involves an automated process optimizing parameters by using autocorrelation and partial autocorrelation plots, as well as various precise measures. The performance of the chosen ARIMA model is confirmed when comparing its forecasts with real data reported after the forecast period. The study successfully forecasts both confirmed and recovered COVID-19 cases across the preventive plan phases in Recife. However, limitations in the model’s performance are observed as forecasts extend into the future. By the end of the study period, the model’s error substantially increased, and it failed to detect the stabilization and deceleration of cases. The research highlights challenges associated with COVID-19 data in Brazil, such as under-reporting and data recording delays. Despite these limitations, the study emphasizes the potential of ARIMA models for short-term pandemic forecasting while emphasizing the need for further research to enhance long-term predictions.

1 November 2020 in Chaos, Solitons & Fractals
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Journal Article
Closed access
JGJoão Gondim
João Gondim
LMLarissa Machado
Larissa Machado

24 June 2020 in Electronic Journal of Differential Equations
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Journal Article
Open access
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CCCesar Castilho
Cesar Castilho
JGJoão Gondim
João Gondim
MMMarcelo Marchesin
Marcelo Marchesin
MSMehran Sabeti
Mehran Sabeti
The goal of this work is to analyze the effects of control policies for the coronavirus (COVID-19) epidemic in Brazil. This is done by considering an age-structured SEIR model with a quarantine class and two types of controls. The first one studies the sensitivity with regard to the parameters of the basic reproductive number R0 which is calculated by a next generation method. The second one evaluates different quarantine strategies by comparing their relative total number of deaths. For more information see https://ejde.math.txstate.edu/Volumes/2020/64/abstr.html

7 November 2024 in arXiv
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NJNelson L. Santos Junior
Nelson L. Santos Junior
JGJoão Gondim
João Gondim
In this paper, we study the optimal control for an SEIR model adapted to the vaccination strategy of susceptible individuals. There are factors associated with a vaccination campaign that make this strategy not only a public health issue but also an economic one. In this case, optimal control is important as it minimizes implementation costs. We consider the availability of two vaccines with different efficacy levels, and the control indicates when each vaccine should be used. The optimal strategy specifies in all cases how vaccine purchases should be distributed. For similar efficacy values, we perform a sensitivity analysis on parameters that depend on the intrinsic characteristics of the vaccines. Additionally, we investigate the behavior of the number of infections under the optimal vaccination strategy.

29 September 2023 in Stats
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Raydonal OspinaRaydonal Ospina
Raydonal Ospina
JOJaciele Oliveira
Jaciele Oliveira
CFCristiano Ferraz
Cristiano Ferraz
ALAndré Leite
André Leite
JGJoão Gondim
João Gondim
In January 2020, the world was taken by surprise as a novel disease, COVID-19, emerged, attributed to the new SARS-CoV-2 virus. Initial cases were reported in China, and the virus rapidly disseminated globally, leading the World Health Organization (WHO) to declare it a pandemic on 11 March 2020. Given the novelty of this pathogen, limited information was available regarding its infection rate and symptoms. Consequently, the necessity of employing mathematical models to enable researchers to describe the progression of the epidemic and make accurate forecasts became evident. This study focuses on the analysis of several dynamic growth models, including the logistics, Gompertz, and Richards growth models, which are commonly employed to depict the spread of infectious diseases. These models are integrated to harness their predictive capabilities, utilizing an ensemble modeling approach. The resulting ensemble algorithm was trained using COVID-19 data from the Brazilian state of Paraíba. The proposed ensemble model approach effectively reduced forecasting errors, showcasing itself as a promising methodology for estimating COVID-19 growth curves, improving data forecasting accuracy, and providing rapid responses in the early stages of the pandemic.

1 January 2022 in Revista Professor de Matemática On line
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Journal Article
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GSGuilherme Silva
Guilherme Silva
JGJoão Gondim
João Gondim