Cristian Cechinel

Dr. Cristian Cechinel

UFSC
orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

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

Representative Publications

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9 June 2020 in Applied Sciences
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Journal Article
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EQEmanuel Queiroga
Emanuel Queiroga
JLJoão Ladislau Lopes
João Ladislau Lopes
KKKristofer Kappel
Kristofer Kappel
Marilton de AguiarMarilton de Aguiar
Marilton de Aguiar
RARicardo Araujo
Ricardo Araujo
CCCristian Cechinel
Cristian Cechinel
Contemporary education is a vast field that is concerned with the performance of education systems. In a formal e-learning context, student dropout is considered one of the main problems and has received much attention from the learning analytics research community, which has reported several approaches to the development of models for the early prediction of at-risk students. However, maximizing the results obtained by predictions is a considerable challenge. In this work, we developed a solution using only students’ interactions with the virtual learning environment and its derivative features for early predict at-risk students in a Brazilian distance technical high school course that is 103 weeks in duration. To maximize results, we developed an elitist genetic algorithm based on Darwin’s theory of natural selection for hyperparameter tuning. With the application of the proposed technique, we predicted the student at risk with an Area Under the Receiver Operating Characteristic Curve (AUROC) above 0.75 in the initial weeks of a course. The results demonstrate the viability of applying interaction count and derivative features to generate prediction models in contexts where access to demographic data is restricted. The application of a genetic algorithm to the tuning of hyperparameters classifiers can increase their performance in comparison with other techniques.

21 March 2025 in Scientific Reports
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Journal Article
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MMMarkson Rebelo Marcolino
Markson Rebelo Marcolino
TPThiago Reis Porto
Thiago Reis Porto
TPTiago Thompsen Primo
Tiago Thompsen Primo
RTRafael Targino
Rafael Targino
VRVinicius Ramos
Vinicius Ramos
CCCristian Cechinel
Cristian Cechinel
Student attrition and academic failure remain pervasive challenges in education, often occurring at substantial rates and posing considerable difficulties for timely identification and intervention. Learning management systems such as Moodle generate extensive datasets reflecting student interactions and enrollment patterns, presenting opportunities for predictive analytics. This study seeks to advance the field of dropout and failure prediction through the application of artificial intelligence with machine learning methodologies. In particular, we employed the CatBoost algorithm, trained on student activity logs from the Moodle platform. To mitigate the challenges posed by a limited and imbalanced dataset, we employed sophisticated data balancing techniques, such as Adaptive Synthetic Sampling, and conducted multi-objective hyperparameter optimization using the Non-dominated Sorting Genetic Algorithm II. We compared models trained on weekly log data against a single model trained on all weeks’ data. The proposed model trained with all weeks’ data demonstrated superior performance, showing significant improvements in F1-scores and recall, particularly for the minority class of at-risk students. For example, the model got an average F1-score across multiple weeks of approximately 0.8 in the holdout test. These findings underscore the potential of targeted machine learning approaches to facilitate early identification of at-risk students, thereby enabling timely interventions and improving educational outcomes.

15 December 2019 in Applied Sciences
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LMLuiz Antonio Buschetto Macarini
Luiz Antonio Buschetto Macarini
CCCristian Cechinel
Cristian Cechinel
MMMatheus Francisco B Machado
Matheus Francisco B Machado
Vinicius RamosVinicius Ramos
Vinicius Ramos
RMRoberto Munoz
Roberto Munoz
Algorithms and programming are some of the most challenging topics faced by students during undergraduate programs. Dropout and failure rates in courses involving such topics are usually high, which has raised attention towards the development of strategies to attenuate this situation. Machine learning techniques can help in this direction by providing models able to detect at-risk students earlier. Therefore, lecturers, tutors or staff can pedagogically try to mitigate this problem. To early predict at-risk students in introductory programming courses, we present a comparative study aiming to find the best combination of datasets (set of variables) and classification algorithms. The data collected from Moodle was used to generate 13 distinct datasets based on different aspects of student interactions (cognitive presence, social presence and teaching presence) inside the virtual environment. Results show there are no statistically significant difference among models generated from the different datasets and that the counts of interactions together with derived attributes are sufficient for the task. The performances of the models varied for each semester, with the best of them able to detect students at-risk in the first week of the course with AUC ROC from 0.7 to 0.9. Moreover, the use of SMOTE to balance the datasets did not improve the performance of the models.

1 January 2013 in Information Processing & Management
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Journal Article
Closed access
CCCristian Cechinel
Cristian Cechinel
Miguel-Angel SiciliaMiguel-Angel Sicilia
Miguel-Angel Sicilia
Salvador Sanchez-AlonsoSalvador Sanchez-Alonso
Salvador Sanchez-Alonso
EGElena García-Barriocanal
Elena García-Barriocanal

22 April 2020 in British Journal of Educational Technology
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CCCristian Cechinel
Cristian Cechinel
XOXavier Ochoa
Xavier Ochoa
HSHenrique Lemos dos Santos
Henrique Lemos dos Santos
JNJoão Batista Carvalho Nunes
João Batista Carvalho Nunes
VRVirginia Rodés
Virginia Rodés
EQEmanuel Queiroga
Emanuel Queiroga

1 January 2014 in Cancer Informatics
Verified
Journal Article
Open access
PSPriscyla Waleska Simões
Priscyla Waleska Simões
NINarjara B. Izumi
Narjara B. Izumi
RCRamon S. Casagrande
Ramon S. Casagrande
RVRamon Venson
Ramon Venson
CVCarlos D. Veronezi
Carlos D. Veronezi
SMSandra A. Manenti
Sandra A. Manenti
Objective: To explore the advantages of using artificial neural networks (ANNs) to recognize patterns in colposcopy to classify images in colposcopy. PURPOSE: Transversal, descriptive, and analytical study of a quantitative approach with an emphasis on diagnosis. The training test e validation set was composed of images collected from patients who underwent colposcopy. These images were provided by a gynecology clinic located in the city of Criciúma (Brazil). The image database ( n = 170) was divided; 48 images were used for the training process, 58 images were used for the tests, and 64 images were used for the validation. A hybrid neural network based on Kohonen self-organizing maps and multilayer perceptron (MLP) networks was used. Results: After 126 cycles, the validation was performed. The best results reached an accuracy of 72.15%, a sensibility of 69.78%, and a specificity of 68%. Conclusion: Although the preliminary results still exhibit an average efficiency, the present approach is an innovative and promising technique that should be deeply explored in the context of the present study.