José Ricardo Nuñez Alvarez

Mr. José Ricardo Nuñez Alvarez

Energy Department, Corporación Universidad de la Costa CUC, Barranquilla, Atlántico, Colombia
orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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30 October 2021 in Sensors
Verified
Journal Article
Open access
PDF file
DHDaily Milanes Hermosilla
Daily Milanes Hermosilla
RCRafael Arturo Trujillo Codorniu
Rafael Arturo Trujillo Codorniu
RLRené López-Baracaldo
René López-Baracaldo
Roberto sagaro zamoraRoberto sagaro zamora
Roberto sagaro zamora
DRDenis Delisle Rodriguez
Denis Delisle Rodriguez
José Ricardo Nuñez AlvarezJosé Ricardo Nuñez Alvarez
José Ricardo Nuñez Alvarez
Motor Imagery (MI)-based Brain–Computer Interfaces (BCIs) have been widely used as an alternative communication channel to patients with severe motor disabilities, achieving high classification accuracy through machine learning techniques. Recently, deep learning techniques have spotlighted the state-of-the-art of MI-based BCIs. These techniques still lack strategies to quantify predictive uncertainty and may produce overconfident predictions. In this work, methods to enhance the performance of existing MI-based BCIs are proposed in order to obtain a more reliable system for real application scenarios. First, the Monte Carlo dropout (MCD) method is proposed on MI deep neural models to improve classification and provide uncertainty estimation. This approach was implemented using Shallow Convolutional Neural Network (SCNN-MCD) and with an ensemble model (E-SCNN-MCD). As another contribution, to discriminate MI task predictions of high uncertainty, a threshold approach is introduced and tested for both SCNN-MCD and E-SCNN-MCD approaches. The BCI Competition IV Databases 2a and 2b were used to evaluate the proposed methods for both subject-specific and non-subject-specific strategies, obtaining encouraging results for MI recognition.
1

22 January 2023 in Sustainability
Verified
Journal Article
Open access
PDF file
OCOriza Ori Candra
Oriza Ori Candra
ACAbdeljelil Chammam
Abdeljelil Chammam
José Ricardo Nuñez AlvarezJosé Ricardo Nuñez Alvarez
José Ricardo Nuñez Alvarez
IMIskandar Muda
Iskandar Muda
HAHikmet Ş. Aybar
Hikmet Ş. Aybar
Growing population and limited energy resources have impacted energy consumption. Limited fossil fuel resources and increased pollution threaten national and human societies. These elements emphasize energy sources. Renewable energy use affects growth. All new energy sources, including renewables, are crucial for global economic growth. Economic and environmental issues have led to new approaches in international environmental law, including the green economy. This study employs structural vector auto-regression (SVAR) to compare the effects and outcomes of increasing the use of renewable energy in the context of economic growth and greenhouse gas emissions in middle income countries (MICs) and high income countries (HICs). The results show that these indicators demonstrate that the production of energy from renewable sources has positive short-term and long-term economic effects with varying contributions. However, renewable energies have a greater impact on the green economy in selected MICs than in selected HICs. Therefore, the promotion of macroeconomic indicators is viewed as one of the reasons for the development of policies to increase energy production from renewable sources in selected countries.

18 June 2023 in Chemosphere
Verified
Journal Article
Closed access
SASulieman I.S. Al-Hawary
Sulieman I.S. Al-Hawary
José Ricardo Nuñez AlvarezJosé Ricardo Nuñez Alvarez
José Ricardo Nuñez Alvarez
AAAmjad Ali
Amjad Ali
ATAbhishek Kumar Tripathi
Abhishek Kumar Tripathi
URUntung Rahardja
Untung Rahardja
WHWoord Hussian
Woord Hussian

1 May 2024 in Heliyon
Verified
Journal Article
Open access
DPDayana Palma-Ramírez
Dayana Palma-Ramírez
BVBárbara Dora Ross Veitía
Bárbara Dora Ross Veitía
PFPablo Font-Ariosa
Pablo Font-Ariosa
AEAlejandro Espinel-Hernández
Alejandro Espinel-Hernández
ARAngel Sanchez Roca
Angel Sanchez Roca
HHHernan Hernández-Herrera
Hernan Hernández-Herrera
The quality of welds is critical to the safety of structures in construction, so early detection of irregularities is crucial. Advances in machine vision inspection technologies, such as deep learning models, have improved the detection of weld defects. This paper presents a new CNN model based on ResNet50 to classify four types of weld defects in radiographic images: crack, pore, non-penetration, and no defect. Stratified cross-validation, data augmentation, and regularization were used to improve generalization and avoid over-fitting. The model was tested on three datasets, RIAWELC, GDXray, and a private dataset of low image quality, obtaining an accuracy of 98.75 %, 90.255 %, and 75.83 %, respectively. The model proposed in this paper achieves high accuracies on different datasets and constitutes a valuable tool to improve the efficiency and effectiveness of quality control processes in the welding industry. Moreover, experimental tests show that the proposed approach performs well on even low-resolution images.

21 June 2021 in IEEE Access
Verified
Journal Article
Open access
DHDaily Milanes Hermosilla
Daily Milanes Hermosilla
RCRafael Arturo Trujillo Codorniu
Rafael Arturo Trujillo Codorniu
RBRene Lopez Baracaldo
Rene Lopez Baracaldo
Roberto sagaro zamoraRoberto sagaro zamora
Roberto sagaro zamora
DRDenis Delisle Rodriguez
Denis Delisle Rodriguez
José Ricardo Nuñez AlvarezJosé Ricardo Nuñez Alvarez
José Ricardo Nuñez Alvarez
Many studies applying Brain-Computer Interfaces (BCIs) based on Motor Imagery (MI) tasks for rehabilitation have demonstrated the important role of detecting the Event-Related Desynchronization (ERD) to recognize the user's motor intention. Nowadays, the development of MI-based BCI approaches without or with very few calibration stages session-by-session for different days or weeks is still an open and emergent scope. In this work, a new scheme is proposed by applying Convolutional Neural Networks (CNN) for MI classification, using an end-to-end Shallow architecture that contains two convolutional layers for temporal and spatial feature extraction. We hypothesize that a BCI designed for capturing event-related desynchronization/synchronization (ERD/ERS) at the CNN input, with an adequate network design, may enhance the MI classification with fewer calibration stages. The proposed system using the same architecture was tested on three public datasets through multiple experiments, including both subject-specific and non-subject-specific training. Comparable and also superior results with respect to the state-of-the-art were obtained. On subjects whose EEG data were never used in the training process, our scheme also achieved promising results with respect to existing non-subject-specific BCIs, which shows greater progress in facilitating clinical applications.
1

17 June 2022 in ISA Transactions
Verified
Journal Article
Closed access
JXJ.S. Xia
J.S. Xia
MKMohamad Khaje Khabaz
Mohamad Khaje Khabaz
IPIndrajit Patra
Indrajit Patra
IKImran Khalid
Imran Khalid
José Ricardo Nuñez AlvarezJosé Ricardo Nuñez Alvarez
José Ricardo Nuñez Alvarez
DTdavood toghraie
davood toghraie