Article Per Year (5 Year)
p-Index From 2020 - 2025
1.048
P-Index
This Author published in this journals
All Journal International Journal of Electrical and Computer Engineering International Journal of Evaluation and Research in Education (IJERE) Jurnal Elemen Indonesian Journal of Electrical Engineering and Computer Science
Hernandez, Cesar
Unknown Affiliation
Computer Science & IT Education Electrical & Electronics Engineering Other

Published : 6 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 6 Documents
Search

 1 
Performance evaluation of a proposal for spectrum assignment based on combinative distance-based assessment multicriteria strategy Hernandez, Cesar; Giral, Diego; Vaca, Tania
International Journal of Electrical and Computer Engineering (IJECE) Vol 14, No 5: October 2024
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v14i5.pp5308-5318

Abstract

Cognitive radio networks offer an alternative to low spectral availability in some frequency bands due to their high demand for frequency channels. This article proposes to improve the spectral assignment based on the combinative distance-based assessment multicriteria algorithm. The metrics obtained are compared with a simple additive weighting algorithm and a RANDOM selection. To establish the algorithm 's performance, five quality-of-service metrics are used: number of handoffs, number of failed handoffs, average bandwidth, average throughput, and cumulative average delay. From the analysis of the results obtained, combinative distance-based assessment (CODAS) presented the best result for the cost metrics with the lowest levels, and for the benefit metrics, the highest levels were obtained.
Novel proposal for a smart electronic taximeter based on microcontroller systems Hernandez, Cesar; Farfán, Ángel; Giral, Diego
International Journal of Electrical and Computer Engineering (IJECE) Vol 14, No 5: October 2024
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v14i5.pp4996-5007

Abstract

Public transport plays a significant role in the economic development of a country, so the state must guarantee its proper functioning, not only in terms of controlling vehicular traffic and generating adequate roads but also in terms of pricing and customer service. This article proposes a smart electronic taximeter that improves customer service quality and provides greater control for the taxi owner. To achieve this, the smart taximeter has a data entry module (keyboard), a location module (global position system), a time module (date and time), a storage module (memory), a display module (light emitting diode array), an auditory module (speech synthesizer), a communication module (Wi-Fi) and a microcontroller that controls the processes of setup, pricing, billing, and accounting. The results have shown a satisfactory response on the part of the client and the entrepreneur since it allows a higher level of inclusion from the auditory output in Spanish and English, as well as to carry out better financial accounting through the storage of information on the place, date and time, start and end, as well as the duration, distance, fare, surcharges, total cost, and number of each taxi service (ride). Finally, the smart electronic taximeter complies with all Colombian resolution No. 88918 relations of the Ministry of Commerce, Industry and Tourism.
Novel method for multi-user collaborative spectral decision in decentralized cognitive radio networks Hernández, Cesar; Giral, Diego; Salgado, Camila
Indonesian Journal of Electrical Engineering and Computer Science Vol 37, No 2: February 2025
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v37.i2.pp888-902

Abstract

Cognitive radio networks positively impact the performance of wireless communications and have proven to be an excellent alternative for efficient and effective use of the radio spectrum. However, few proposals collaboratively work on decision-making in decentralized cognitive radio networks. The present work refers to a novel method and device that reduces the rate of channel changes during secondary user communications in decentralized cognitive radio networks through a collaborative spectral decision between several secondary users while allowing multiple secondary users access to the network. This proposal consists of a multi-user unit that regulates the access of multiple secondary users (SUs) to the spectrum, a priority unit that guarantees timely access to the SUs according to their level of importance, and a prediction unit that forecasts the arrival time of the primary user (PU). This multichannel unit regulates the assignment of multiple spectral opportunities to the SU according to the type of application it is using and a unit of deep learning that determines which spectral opportunity(s) are most suitable for each SU and spectral allocation. The results obtained allow us to satisfactorily validate the proposal developed and corroborate the importance of collaborative work in decision-making to select spectral opportunities.
The impact of project-based learning on mathematics interest and self-efficacy among senior high school students Rahman, Arief Aulia; Usalmy, Nyak Wha; Hernández, César; Refugio, Craig N
Jurnal Elemen Vol 11 No 1 (2025): January
Publisher : Universitas Hamzanwadi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29408/jel.v11i1.27622

Abstract

This research sought to explore how the Project-Based Learning (PjBL) model affects the learning interest and self-efficacy of eleventh-grade students in Senior High School. Employing a quantitative quasi-experimental design, the study utilized a sample of eleventh-grade students selected through simple random sampling. Data were gathered using questionnaires and observational methods and analyzed using a multivariate analysis of variance (MANOVA) test. The results underscored the notable influence of the PjBL model in enhancing learning interest and self-efficacy. The PjBL approach positively affected these variables in the experimental group of 28 students. The robustness of these results was confirmed by Pillai's Trace, Wilks' Lambda, Hotelling's Trace, and Roy's Largest Root tests, each demonstrating F-values with a significance level of 0.000, well below the threshold of 0.05. Moreover, the Coefficient of determination (R²) revealed that the PjBL model accounted for 73.5% of the variance in learning interest and 90.2% in self-efficacy, with the remaining variance being attributable to other factors not addressed in this study.
Benchmarking spectral handoff rate performance in cognitive wireless networks with real multi-user access Hernández, Cesar; Giral, Diego; Martínez, Fredy
Indonesian Journal of Electrical Engineering and Computer Science Vol 39, No 1: July 2025
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v39.i1.pp190-201

Abstract

Cognitive radio (CR) has proven to be an excellent alternative to the problem of inefficient spectrum use in wireless networks. However, the vast majority of proposals found in the current literature are restricted to the access of a single secondary user (SU) to the network, and the few proposals with multiple access do not take into account the access of other primary users (PUs) during the opportunistic transmission of the SU. The objective of this work is to perform a comparative evaluation of the spectral handoff (SH) rate in cognitive wireless networks with multi-user access in an environment with other PUs interacting. To carry out this evaluation, four SH models with better performance were selected: deep learning (DL), feedback fuzzy analytic hierarchy process (FFAHP), simple additive weighting (SAW), and Naïve Bayes (NB), which were validated according to the metric of the number of total handoffs, under four scenarios given by the combination of the following parameters: low spectral availability, high spectral availability, active presence of others SUs, and passive presence of others SUs. The results show that each model performs well according to the scenario in which it is executed, suggesting an adaptive multi-model as a proposal.
Enhancing learning outcomes through course redesign using self-assessment and inquiry models Martinez, Fredy; Hernández, César; Giral, Diego
International Journal of Evaluation and Research in Education (IJERE) Vol 14, No 5: October 2025
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijere.v14i5.32215

Abstract

This study addresses the challenge of enhancing learning outcomes in propaedeutic education by redesigning an undergraduate deep learning course. To achieve this, the self-assessment and quality model (SQM) was combined with the community of inquiry (CoI) framework, which emphasizes cognitive, social, and teaching presence in online education. The redesigned course aligns with the guidelines of the Colombian Ministry of National Education and incorporates continuous feedback from students. Initial implementation led to improved student performance but revealed gaps in perceived learning experiences. Iterative adjustments were made to the course design based on CoI survey results, particularly focusing on increasing teacher involvement. The findings demonstrate that integrating SQM with a responsive, design-based approach can significantly improve learning outcomes and student satisfaction. This study highlights the importance of dynamic course design in higher education and offers a replicable model for other institutions.
Co-Authors Farfán, Ángel Giral, Diego Martinez, Fredy Rahman, Arief Aulia Refugio, Craig N Salgado, Camila Usalmy, Nyak Wha Vaca, Tania