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 18
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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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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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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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Integration of renewable energies in conventional power systems based on computational reliability

2019 , Cumbajín Alferez, Myriam , Ramírez L. , Gordón C.

We report the successful computational reliability of integrating renewable energy into conventional electric power systems. According to renewable resources available in the province of Imbabura in Ecuador, where there are sufficient renewable resources to generate clean energy with three types of technology, such as wind energy, photovoltaic solar energy and thermoelectric energy. We have been able to conduct two fundamental case studies, and then calculate reliability indices using the non-sequential Monte Carlo method using Matlab programming. The reliability indices allowed us to evaluate the reliability of the system. Due to the fact that the lower the reliability index, the higher the reliability of the system. As a result, this paper provides a promising method for increasing the reliability of electric power systems and supporting the future integration of renewable energies. © 2019, Associacao Iberica de Sistemas e Tecnologias de Informacao. All rights reserved.

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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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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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Multi-criteria analysis of turbines for pico-hydro power plant in water irrigation channel

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

We present the Multi-criteria Analysis of turbines for Pico-Hydro Power plant in Ambato–Huachi–Pelileo water irrigation channel. Not only, we have been able to perform a turbine selection using the common requirements like head and flow rate. But also, we have taken into account a multi-criteria analysis by considering: Quantitative criteria, such as Efficiency and Size, combined with Qualitative criteria, such as Maintainability & Serviceability, Portability, Modularity, and Installation Environment requirements. The criteria were analyzed by using the analytical hierarchy process (AHP). We have reviewed different turbine options for being used in a pico-hydropower plants, from the analytical hierarchy process. We have concluded that Michell Banki turbine is the recommendable option in terms of easy build and highly efficient. The study of the requirements for the development of Pico-Hydro Power plant in Ambato–Huachi–Pelileo water irrigation channel in Ecuador will be a promising method for meeting the energy needs using renewable resources and avoiding the conventional fossil fuels or any other approach that affects the environment. © Springer Nature Switzerland AG 2020.

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Multiband Broadband Modulator Implementation on Field-Programmable Gate Array

2020 , Castro, C. , Gordón, C. , Encalada, P. , Cumbajín Alferez, Myriam

The proper management of resources available in FPGA’s is one of the main issues that designers must consider when implementing a high bandwidth communications system. For this reason, we report the hardware-efficient implementation, for mapping stages and pulse shaping, of broadband multi-level QAM signals, in Field-Programmable Gate Array (FPGA) devices. The process for designing the system is based on the large capacity of analog-digital (ADC) converters that exist today, in this case the ADC has a sampling rate of 5 GSPS, which allows the transmission of signals with bandwidths of about 2.5 GHz. The model implements in the same polyphase FIR structure multiplier-less the mapping schemes Q-PSK, 16-QAM, 64-QAM y 256-QAM together with the RRC filter. As a result, this implementation shows that the proposed architecture eliminates the use of dedicated multipliers which would be around 3150 if conventional methods were used. The Error Vector Module is used as a figure of merit in the selection of the RRC filter and the digital quantization levels. We achieved the target frequency for hardware operation at 312.5 MHz con un factor de interpolation de 16 and an EVM < 2%. Also, Hardware Description Language (HDL) models are validates in test benches with reference to the finite precision models of Simulink. © 2020, Springer Nature Switzerland AG.

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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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