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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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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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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Health and Educational Impacts Reduction Using a Supervisory Control and Data Acquisition Web System

2018 , Davila L. , Robalino F. , Gordon C. , Cumbajín Alferez, Myriam

We present the design and implementation of a Supervisory Control and Data Acquisition SCADA web system of pollution factors such as Nitrogen Dioxide (NO2), Carbon Dioxide (CO2) and Carbon Monoxide (CO) in order to manage them, providing comfort in indoor environments. The SCADA web system allows a comparative analysis of the recorded information with the alert, alarm and emergency levels, established in the Ecuadorian air quality regulations, annex 4 of Book VI of the Unified Legislation of Secondary Legislation of the Ministry of the Environment., The SCADA web system performs the comparison of the registered information, with the physical agents of environmental comfort, established in the ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) standards. In the process of stabilization of the pollution factors, in indoor environments, air ionizers are used, which emit negative ions to maintain the standardized range in micrograms per cubic meter (3). Finally, we have been able to develop a SCADA web system for controlling pollution factors in indoor environments thanks to the integration of firebase (Android Studio), authentication (Facebook), notification (Database and Web Server), control and monitoring (Android Studio) interfaces. Besides, the SCADA web system allows preventing long term health problems such as allergic reactions, physical exhaustion and respiratory diseases, which influence academic performance during study days in educational institutions. © 2018 IEEE.

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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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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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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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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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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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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. , Cumbajín Alferez, Myriam

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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Technical Comparisons of Antennas at a Frequency of 3 GHz

2024 , Yessika Jaramillo , Alex Calle , Cumbajín Alferez, Myriam , Carlos Gordón

This paper presents a detailed performance comparison between two widely used antenna types: the Patch Antenna with Insert Field and the 1×4 Linear Array, operating at a frequency of 3 GHz. Using Ansoft Designer software, simulations and modeling were conducted for both antennas, analyzing key parameters such as directivity, gain, reflection coefficient, and radiation pattern. The results show that the 1×4 Linear Array exhibited higher directivity and gain compared to the Patch Antenna with Insert Field. Furthermore, the 1×4 Linear Array demonstrated greater flexibility in controlling the beam pointing angle. On the other hand, the Patch Antenna with Insert Field stood out for its ease of implementation and its capability for more omnidirectional radiation

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