Cumbajín Alferez, Myriam

Preferred name

Main Affiliation

Facultad de Arquitectura, Diseño y Artes

Ambato

myriamcumbajin@uti.edu.ec

ORCID

0000-0001-9993-7095

Scopus Author ID

57198450868

Now showing 1 - 10 of 21

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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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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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Low-Cost Signal Generator: Design and Implementation
(2025)
Sharon Solano
;
Kevin Diaz
;
Carlos Gordon
;
Cumbajín Alferez, Myriam
This document meticulously details the design and implementation process of a Low-Cost Signal Generator using the AD9833 module. This device can generate sinusoidal, triangular, and square signals with a high degree of precision, making it ideal for applications in electronics laboratories and educational projects. The methodology employed is divided into four main stages: circuit design, simulation, fabrication, and characterization tests of the signal generator. Operational tests demonstrated that the generator meets the design specifications, producing stable signals in a frequency range of 0.1 Hz to 12.5 MHz. The features of the AD9833 module allow for flexible configuration of waveforms and frequencies, facilitating its use in various testing and development applications. This work was developed to provide a solid foundation for the creation of economical and efficient signal generators, thus contributing to the accessibility of advanced tools in educational and research environments.
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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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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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Convolutional neural network oriented to the gesticulation control of an interactive social robot with humanoid aspect [Red neuronal convolucional orientado a la gesticulación de un robot social interactivo con aspecto humanoide]
(2019)
Arias E.
;
Encalada P.
;
García M.
;
Granizo C.
;
Tigre F.
Social robots present the boom of an infinity of investigations in terms of design and control, these in turn approach with greater intensity to be our partners at home or work, however, still lack similar social interaction skills to the human being. This paper presents the implementation of a convolutional neuronal network algorithm aimed at the arrest of emotions for decision-making in the gesticulation of the social robot with a humanoid appearance. In addition, emphasis is placed on the use of visemas as a unit of labial movement for improve the human-robot interaction in any field in which the social robot can be used, be it teaching, therapies, safe navigation, etc., simultaneously coordinating and similar to the human naturalness the movement of servomechanisms of the mouth and the synthesized audio of the text that the robot gives in response. © 2019, Associacao Iberica de Sistemas e Tecnologias de Informacao. All rights reserved.
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Reverse Engineering for the Ecowitt WS90 Weather Station
(2026)
Cumbajín Alferez, Myriam
This article presents a comprehensive reverse engineering study applied to the Ecowitt WS90 weather station, a self-contained device designed to collect essential environmental data such as temperature, humidity, wind direction and speed, light and UV radiation levels, and precipitation. The main objective of this work is to gain a deep understanding of the internal workings of the weather station through meticulous analysis of its hardware and software components. The methods used are described in detail, including careful disassembly of the device, precise identification of key components, and scanning and disassembling the embedded firmware. Additionally, significant challenges encountered during the rigorous reverse engineering process are discussed and possible improvements or modifications to the original design based on the findings are proposed. The results obtained in this study provide an unprecedented insight into the internal workings of the Ecowitt WS90 weather station, contributing to a deeper understanding of environmental monitoring systems in general. The detailed findings presented in this article can be very useful for future developments and advances in the field of environmental monitoring, by facilitating the optimization of existing devices or the design of new innovative solutions. Furthermore, this work lays the foundation for future research and more specialized studies in the area of reverse engineering applied to environmental data acquisition systems. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.
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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.
24
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Rectenna Patch-Type Array for Capture of Electromagnetic Energy
(2024)
Cumbajín Alferez, Myriam
;
Sánchez, Patricio
;
Fausto Tello
;
Carlos Gordón
This research project is focused on gathering information on rectennas, as well as on patch antenna arrays for Energy Harvesting Systems designed at frequencies up to 3 Ghz, in addition to a simulation and implementation of a rectenna consisting of elements and technology suitable for electromagnetic energy harvesting systems; and at the same time analyze the results obtained from the tests carried out in order to demonstrate its efficiency in the aforementioned systems. The design of this prototype was made in Ansys HFSS software, which allowed us to make a 2×2 array of rectangular patch antennas, in which λ/4 transformers are used to couple the transmission lines to a characteristic impedance of 50 Ω; at the same time the design of a multiplier and voltage rectifier for high frequencies is also performed, in this case for 2.4 Ghz; in such a way that by joining the antenna array with the rectifier, a useful rectenna for electromagnetic energy collection is obtained.
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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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Cumbajín Alferez, Myriam

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