Oscar Almanza-Conejo

Mr. Oscar Almanza-Conejo

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

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

Representative Publications

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26 September 2022 in Neural Computing and Applications
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Journal Article
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OAOscar Almanza-Conejo
Oscar Almanza-Conejo
DODora Luz Almanza Ojeda
Dora Luz Almanza Ojeda
JCJose Luis Contreras-Hernandez
Jose Luis Contreras-Hernandez
MIMario Alberto Ibarra-Manzano
Mario Alberto Ibarra-Manzano

1 October 2024 in Technologies
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Journal Article
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FGFernando Daniel Hernandez Gutierrez
Fernando Daniel Hernandez Gutierrez
EAEli Gabriel Avina-Bravo
Eli Gabriel Avina-Bravo
DGDaniel Fernando Zambrano Gutierrez
Daniel Fernando Zambrano Gutierrez
OAOscar Almanza-Conejo
Oscar Almanza-Conejo
MIMario Alberto Ibarra-Manzano
Mario Alberto Ibarra-Manzano
Juan Gabriel Avina-CervantesJuan Gabriel Avina-Cervantes
Juan Gabriel Avina-Cervantes
The timely detection and accurate localization of brain tumors is crucial in preserving people’s quality of life. Thankfully, intelligent computational systems have proven invaluable in addressing these challenges. In particular, the UNET model can extract essential pixel-level features to automatically identify the tumor’s location. However, known deep learning-based works usually directly feed the 3D volume into the model, which causes excessive computational complexity. This paper presents an approach to boost the UNET network, reducing computational workload while maintaining superior efficiency in locating brain tumors. This concept could benefit portable or embedded recognition systems with limited resources for operating in real time. This enhancement involves an automatic slice selection from the MRI T2 modality volumetric images containing the most relevant tumor information and implementing an adaptive learning rate to avoid local minima. Compared with the original model (7.7 M parameters), the proposed UNET model uses only 2 M parameters and was tested on the BraTS 2017, 2020, and 2021 datasets. Notably, the BraTS2021 dataset provided outstanding binary metric results: 0.7807 for the Intersection Over the Union (IoU), 0.860 for the Dice Similarity Coefficient (DSC), 0.656 for the Sensitivity, and 0.9964 for the Specificity compared to vanilla UNET.

10 March 2025 in IEEE Journal of Biomedical and Health Informatics
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Journal Article
Closed access
OAOscar Almanza-Conejo
Oscar Almanza-Conejo
Juan Gabriel Avina-CervantesJuan Gabriel Avina-Cervantes
Juan Gabriel Avina-Cervantes
AGARTURO GARCIA-PEREZ
ARTURO GARCIA-PEREZ
MIMario Alberto Ibarra-Manzano
Mario Alberto Ibarra-Manzano
Electroencephalograms provide a non-invasive and effective method for studying emotion recognition and developing Artificial Intelligence (AI) models to understand human behavior and decision-making processes. This study involved testing several machine learning classification kernels to develop an accurate emotion recognition model capable of classifying emotions stimuli such as “Boring,” “Calm,” “Happy,” and “Fear” during gameplay. An emotion classifier was assessed using the publicly available database for an emotion recognition system based on EEG signals and various computer games (GAMEEMO). The signal processing method, referred to as Regression EEG (REGEEG), involves an efficient electrode pairing selector developed for EEG signal processing using a regression algorithm, rotation matrices, director vectors, and robust statistical and polynomial feature extraction. REGEEG and feature extraction methods were evaluated with 28 machine learning kernels, resulting in five kernels with classification performance above 80%, with the K-Nearest Neighbors (k-NN) based model outperforming the rest (achieving over 95% accuracy, F1-Score, and kappa-score). REGEEG performance was further validated using 30 Cross-Validation (CV) folders and 28 in the Leave-one Subject-out (LoSo) technique without impacting the average classification performance. The classification highlights revealed low variance in the CV, while the LoSo approach helped identify outliers in the GAMEEMO dataset. Furthermore, the EEG pair channels selector demonstrates superior performance in classification, indicating a correlation between features and each processed pair of channels.

10 April 2024 in IEEE Access
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Journal Article
Open access
OAOscar Almanza-Conejo
Oscar Almanza-Conejo
Juan Gabriel Avina-CervantesJuan Gabriel Avina-Cervantes
Juan Gabriel Avina-Cervantes
AGARTURO GARCIA-PEREZ
ARTURO GARCIA-PEREZ
MIMario Alberto Ibarra-Manzano
Mario Alberto Ibarra-Manzano
Popular comments suggest that continuous exposure of children and adolescents to video games yields a non-benefit behavior in the players’ mental health. Contrarily, several studies have proven that commercial and serious games improve mental activity; some are used in treating psychological and physical disorders. This paper presents a method based on electroencephalogram signals analysis to classify multiple emotions recorded from subjects’ gameplay seasons. In the core of this study, a self-assessed labeling method is evaluated using the Force, EEG, and Emotion Labelled Dataset (FEEL) for emotion recognition tasks. Besides, a 1-D Local Binary Pattern (LBP) method transforms the EEG temporal behavior to extract time-frequency features. Complementarily, the database artifacts were removed using a novel Conflict Learning approach for machine learning models, associating the extracted samples with the subjects’ emotion labeling. A semi-supervised clustering method was employed to show the similarity between self-assessed subjects’ labels. Finally, numerical results suggested a conflict between 23 original labels, improving the classification by over 92% in accuracy for 19 self-assessed classes.

11 June 2022
Verified
Book Chapter
Closed access
PDF file
OAOscar Almanza-Conejo
Oscar Almanza-Conejo
DODora Luz Almanza Ojeda
Dora Luz Almanza Ojeda
JCJose Luis Contreras-Hernandez
Jose Luis Contreras-Hernandez
MIMario Alberto Ibarra-Manzano
Mario Alberto Ibarra-Manzano