Cumbajín Alferez, Myriam
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Preferred name
Cumbajín Alferez, Myriam
Main Affiliation
Ambato
Email
myriamcumbajin@uti.edu.ec
ORCID
Scopus Author ID
57198450868

Research Output
Now showing 1 - 10 of 19
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Hybrid Storage System Based on Rectenna and Photovoltaic Cells for Low Power IoT Wireless Devices

2023 , Cumbajín Alferez, Myriam , Valle M. , Gordón C. , Peñafiel C.

This article presents the results of a research project, in which a system for harvesting Radio Frequency energy in the Wi-Fi frequency and a system for harvesting solar energy were developed, later they were connected. The two voltage sources collected in series to add them and an MT3608 circuit was added to its output, to have a regulated voltage between 5 to 27 V at the system output and charge a 3.7 V lithium battery at 300 mA, and a 9 V battery. The antenna that was designed was a patch-type Sierpinski carpet until the second interaction, which together with a two-stage Cockcroft Walton multiplier is improved to acquire up to 254 mV, the solar panel on the other hand was a 6 V at 150 mA, when implementing the entire system, 27 V were acquired at the output, a voltage that, thanks to the MT3608 regulator, can be regulated to obtain a sufficiently voltage at the output of the system. To carry out several systems loads tests in different day conditions such as: cloudy, sunny and at night, managing to charge 90% 3.7 V and 9 V batteries in 4 h. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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Biosignal Monitoring System Through an Interface to Optimize People’s Emotional Well-Being

2025 , Kevin Gamboa , Dario Guaman , Carlos Gordon , Myriam Cumbajin

This document presents the development of a Node-RED application with an interactive graphical interface for the visualization of emotional biosignals, allowing users to monitor and analyze their emotional state. The objective is to record relevant information on the implementation of algorithms in real time and the integration of sensors such as the MAX30100 and AD8232 ECG, together with an ESP32 and electrodes to take the samples, in order to identify emotional patterns using predefined thresholds. The aim is to optimize the efficiency of the system by improving biosignal transmission algorithms, minimizing resource consumption, and guaranteeing fast and fluid visualization of emotions on OLED screens, to improve the overall user experience. In this study, a methodology divided into four phases was used: research, development, integration, and optimization. Once the application was implemented, the results obtained in the identification of emotional patterns were compared and the algorithms that offered the best performance were optimized. Finally, an intuitive graphical interface was created in Node-RED that allows users to efficiently visualize and monitor their emotional biosignals, functioning as a tool to optimize people’s emotional well-being.

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Machine Learning Algorithms for Filtering Data Acquired by Arduino

2024 , Mateo Llerena , Jessica López , Cumbajín Alferez, Myriam , Carlos Gordón

In this paper, we developed an artificial intelligence-based data filtering algorithm to improve the accuracy and reliability of MPU6050 sensor measurements. Using the Edge Impulse platform, we trained and optimized the machine learning model for real-time processing of accelerometer and gyroscope readings. The solution was implemented on the ESP32 with a sampling rate of 600 Hz. The experimental results validated the effectiveness of the solution, highlighting its relevance in applications requiring real-time monitoring

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Smart Antenna Array for Optimal Electromagnetic Energy Capture

2023 , Cumbajín Alferez, Myriam , Sánchez, Patricio , Escobar E. , Gordón C.

Smart antennas are currently one of the most exploited fields in terms of wireless networks, allowing high data transmission capacities, this is achieved by focusing the radiation on the desired direction and adjusting to the environment and conditions in which communications are developed. Smart antennas employ a set of radiating and emitting and combining elements organized in the form of arrangements connected at a common point to guarantee the required power, the signals from these elements are combined to form a moving beam pattern that follows a pattern determined by the user or designer. The consumption of energy within communication systems is considered a big problem and a challenge when carrying out implementations in media where the storage or recharging of the end terminals is complicated by their location, this trend grows with the presence of the Internet of the IoT things, where it is directly dependent on the construction of a large wireless network that allows everything to be interconnected, for this reason there are investigations in the 2.4 and 5.8 GHz bands and represents future work for the 5th Generation (5G) cell phone. The great possibility of collecting electromagnetic energy from densely populated urban areas becomes a great renewable source of power for communication devices for both existing Wi-Fi technology and new technologies such as the 5G network. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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RF Energy Harvesting System Based on Spiral Logarithmic Dipole Rectenna Array

2023 , Cumbajín Alferez, Myriam , Sánchez, Patricio , Pillajo D. , Gordón C.

This paper presents the development, design, simulation and fabrication of a logarithmic spiral antenna array for the electromagnetic energy collection system independent of frequency, compact in microstrip technology, low cost and operating within a range of frequencies. 1 to 4 GHz, are designed using the CST Studio software that allows modeling and simulating essential parameters such as radiation lobes, VSWR, power, gain, parameter S11. From these simulations the printing is done on an RF4 substrate with a thickness of 1.6 mm, a dielectric constant of 4.4 and an input impedance of 50 Ω. The resonator structure antenna with dimensions of 190 × 210 mm. The frequencies obtained with the rectenna matrix, since it offers good performance for electromagnetic energy harvesting applications that operate in standard frequencies such as GSM, WiFi, LTE which are available in the environment and allows us to collect energy. To obtain electrical energy as part of the design of a frequency rectifier which is optimized with the application of the Schottky diode. In addition, its construction of the rectenna matrix was carried out based on the proposed design, then performance tests and validation of the prototype were carried out using the miniVNA Tiny spectrum verifier, and finally energy storage tests were carried out. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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Improving PV Power Prediction Based on GRU and Meteorological Factors

2026 , Cumbajín Alferez, Myriam , Ruxandra Stoean , José Aguado , Gonzalo Joya

The gradual integration of renewable solar energy sources represents a major step toward sustainability, which is why the main objective of this study is to design an optimized GRU architecture for hourly prediction of photovoltaic generation, considering both single-step and multi-step forecasting. A recurrent neural network with a four-layer GRU structure was implemented, selected after a comparative validation process in which different depths were evaluated. This configuration balanced accuracy, stability, and generalization capacity, improving the model’s ability to capture complex relationships between the endogenous variable (photovoltaic generation) and a set of eight exogenous meteorological variables. This architecture proved robust to different sets of predictors, maintaining consistent performance under different input configurations. The result is a reliable prediction and forecast error for a power generation system with meteorological factors typical of Ibarra, Ecuador. Among the evaluation metrics used, the mean square error decreased by 19.61% and 23.69% for single-step prediction and multi-step forecasting, respectively. Therefore, the GRU model has managed to reduce the error by a moderate percentage, with a significant difference, supported by the evaluation metrics and the Wilcoxon-Mann-Whitney U test, it was possible to reduce the error obtaining a p-value less than 0.05, which represents that the data groups without meteorological factors and the data groups with meteorological factors are statistically different and therefore the error reduction is significant. Through this, it is demonstrated that including eight exogenous attributes reduces prediction and forecasting errors

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Suitable electric generator for pico-hydro power plant in ambato–huachi–pelileo water irrigation channel

2020 , Cumbajín Alferez, Myriam , Sánchez, Patricio , Hidalgo, A. , Gordón, C.

We present the analysis of the selection of electric generator suitable for Pico-Hydro Power Plant in the Ambato-Huachi-Pelileo irrigation channel in Ecuador. For which a meticulous literary review has been carried out about the main characteristics of the Pico-Hydro Power Plant as it is the height, the hydric resource, the turbine and the generator. Considering the water resource, which in our case is provided by the Ambato-Huachi-Pelileo irrigation channel, the parameters of low height and slow speed have been taken around 1.6 m3/s, which has allowed us to analyze the generator suitable for the required Pico-Hydro Power Plant. Therefore, the study conducted has allowed us to conclude that the electric generator suitable for the Pico-Hydro Power Plant in the Ambato-Huachi-Pelileo irrigation channel is a radial flux permanent magnet generator that is capable of providing sufficient electrical power with a simple structure, low revolutions, and high efficiency. Also, a Matlab simulation was developed in order to predict the power which is capable of provide the radial flux permanent magnet generator which in this case is 3.8 KW. This work aims to provide several benefits to the society bordering the irrigation channel, such as generating energy for self-consumption as a contribution to the lighting of the channel at no cost to the public in order that it is not dangerous for the passers at night and providing the ability for maintenance works at any time. © Springer Nature Switzerland AG 2020.

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Software for Horns, Reflectors and Antennas in RF Circuits

2024 , Jorge Unapucha , Ruales, María Belén , Carlos Gordón , Cumbajín Alferez, Myriam

The software developed in Python, fulfills the main objective of facilitating the calculation, graph, design and analysis of horns, reflectors and antennas. Through an intuitive and dynamic graphical interface, with text boxes, users can enter calculation parameters, among which can be the operating frequency, physical dimensions and electrical characteristics, this depending on the type of element that is or will be manipulated within the software, this to configure and observe the different values of the metrics of the different elements of the circuit. The program has numerical modeling and simulation algorithms that allow the analysis of the behavior of horns, reflectors and antennas in the radio frequency domain. Among the aspects evaluated are the radiation, gain, directivity, efficiency and bandwidth of the devices

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Michell-Banki a Promise Turbine for Pico-Hydro in Water Irrigation Channel

2020 , Ibañez, L. , Escobar, L. , Hidalgo, A. , Gordón, C. , Cumbajín Alferez, Myriam

We report the design, manufacture, and testing of the Michell-Banki turbine by using the hydraulic data of the Ambato - Huachi - Pelileo water irrigation channel in the Tungurahua province in Ecuador. The turbine has the blade, impeller, flange and shaft that are purely plastic materials because they will be subject to the action of water and thus be able to extend the life of the components. For an optimal design it was considered an efficient alternative, which is the manipulation of the turbine, it should be portable and as light as possible. When performing the tests, it was determined that there is an error around 14% between speed and torque calculations, while the greater efficiency of the turbine is at the exit of each oval of the channel. The main contribution of the present work is to provide the required promise component in a Pico-Hydro that is expected to be implemented in the water irrigation channel. Also this work aims to provide several benefits to the society bordering the irrigation channel, such as generating energy for self-consumption as a contribution to the lighting of the channel at no cost to the people. © 2020, Springer Nature Switzerland AG.

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Multiband Microstrip Antennas for Energy Harvesting Systems

2022 , Gordón C. , Criollo W. , Cumbajín Alferez, Myriam , Peñafiel C.

In this paper, the development of two microstrip antennas for electromagnetic energy harvesting systems is presented. The first one, is the Hybrid Resonator Planar Structure Antenna operating at a specific 900 MHz frequency, while the other is an Archimedean Spiral Multiband Antenna working in a frequency range of 1 to 3 GHz, both were developed for energy harvesting systems. Both antennas were designed using CST Studio software and fabricated in a low cost FR4 substrate with a thickness of 1.6 mm, dielectric constant of 4.4 and an input impedance of 50 Ω. The frequencies achieved with the antennas are very promising, as it offers good performance for electromagnetic energy harvesting applications since it operates at standard frequencies such as GSM, Wi-Fi, LTE and UMTS which are available in the environment and allow us to harvest energy at any place and any time. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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