Varela Aldas, José
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Varela Aldas, José
Main Affiliation
Ambato
Email
josevarela@uti.edu.ec
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Scopus Author ID
57192546163

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Adaptive Jamming Mitigation for Clustered Energy-Efficient LoRa-BLE Hybrid Wireless Sensor Networks

2025 , Carolina Del-Valle-Soto , Leonardo J. Valdivia , Ramiro Velázquez , José A. Del-Puerto-Flores , Varela Aldas, José , Paolo Visconti

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Sizing and Characterization of Load Curves of Distribution Transformers Using Clustering and Predictive Machine Learning Models

2025 , Pedro Torres-Bermeo , Kevin López-Eugenio , Carolina Del-Valle-Soto , Guillermo Palacios-Navarro , Varela Aldas, José

The efficient sizing and characterization of the load curves of distribution transformers are crucial challenges for electric utilities, especially given the increasing variability of demand, driven by emerging loads such as electric vehicles. This study applies clustering techniques and predictive models to analyze and predict the behavior of transformer demand, optimize utilization factors, and improve infrastructure planning. Three clustering algorithms were evaluated, K-shape, DBSCAN, and DTW with K-means, to determine which one best characterizes the load curves of transformers. The results show that DTW with K-means provides the best segmentation, with a cross-correlation similarity of 0.9552 and a temporal consistency index of 0.9642. For predictive modeling, supervised algorithms were tested, where Random Forest achieved the highest accuracy in predicting the corresponding load curve type for each transformer (0.78), and the SVR model provided the best performance in predicting the maximum load, explaining 90% of the load variability (R2 = 0.90). The models were applied to 16,696 transformers in the Ecuadorian electrical sector, validating the load prediction with an accuracy of 98.55%. Additionally, the optimized assignment of the transformers’ nominal power reduced installed capacity by 39.27%, increasing the transformers’ utilization factor from 31.79% to 52.35%. These findings highlight the value of data-driven approaches for optimizing electrical distribution systems.

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A Comprehensive Review of Behavior Change Techniques in Wearables and IoT: Implications for Health and Well-Being

2024 , Varela Aldas, José , Del-Valle-Soto C. , López-Pimentel J.C. , Nolazco-Flores J.A. , Velázquez R. , Varela-Aldás J. , Visconti P.

This research paper delves into the effectiveness and impact of behavior change techniques fostered by information technologies, particularly wearables and Internet of Things (IoT) devices, within the realms of engineering and computer science. By conducting a comprehensive review of the relevant literature sourced from the Scopus database, this study aims to elucidate the mechanisms and strategies employed by these technologies to facilitate behavior change and their potential benefits to individuals and society. Through statistical measurements and related works, our work explores the trends over a span of two decades, from 2000 to 2023, to understand the evolving landscape of behavior change techniques in wearable and IoT technologies. A specific focus is placed on a case study examining the application of behavior change techniques (BCTs) for monitoring vital signs using wearables, underscoring the relevance and urgency of further investigation in this critical intersection of technology and human behavior. The findings shed light on the promising role of wearables and IoT devices for promoting positive behavior modifications and improving individuals’ overall well-being and highlighting the need for continued research and development in this area to harness the full potential of technology for societal benefit. © 2024 by the authors.

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Detection System for Domestic Environmental Pollutants Based on ThingSpeak

2023 , Varela Aldas, José , Miranda M. , Lasluisa G.

Internet of things platforms is essential components for project development with connectivity. Thus, these have positioned themselves in the market by offering multiple cloud services, such as a database, application programming interface, and more. This paper presents a system that collects data from air concentration sensors to detect the presence of pollutants. The electronic circuit uses a system-on-chip with WiFi connectivity and the MQ2 and MQ3 sensors, which detect liquefied petroleum gas and alcohol concentrations in the air, respectively. The system is based on the ThingSpeak platform, which receives and graphs data to see readings outside expected ranges. The results present the concentration levels of the MQ2 and MQ3 sensors, indicating the correct functioning of the system, and future applications of the proposed design are discussed. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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An assessment of a ROS class using an educational mobile robot

2024 , Varela Aldas, José , Junta, Christian , Buele, Jorge , Guillermo Palacios-Navarro

The Robot Operating System (ROS) is a middleware that standardizes robot programming, both in simulation and with real equipment. Despite this open-source tool being available for several years, there's still a need to enhance its utilization in robotics education across all educational levels. In this study, a ROS class is assessed among university students using a commercial educational robot. The primary objective is to measure academic emotions in learning and student performance to determine the impact of the class using the open-access tool from a GitHub repository (https://github.com/joseVarelaAldas/ROS-Crowbot). This tool is based on the rosserial package, compatible with the ESP32 board. For class, CrowBot robots connected to the local wireless network via WiFi are used. TThe participants in this study were eight students from an electronics degree program at a higher education institution, who had no prior experience with ROS and received practical training using the educational mobile robot. For data collection on class performance, three parameters are assessed: execution time, functionality, and motivation, and to measure academic emotions, a validated self-report instrument is used. The results show an overall performance of 82.1%, and in the self-report on academic emotions, a high score in enjoyment (95%) and the lowest score in boredom (24.1 %) were obtained. In conclusion, the repository provides an interesting, practical, and accessible tool for an introduction into the world of robotics using ROS.

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3D Object Reconstruction Using Concatenated Matrices with MS Kinect: A Contribution to Interiors Architecture

2020 , Buele, Jorge , Varela Aldas, José , Castellanos E.X. , Jadán Guerrero, Janio , Barberán J.

Interior architecture is part of the individual, social and business life of the human being; it allows structuring the spaces to inhabit, study or work. This document presents the design and implementation of a system that allows the three-dimensional reconstruction of objects with a reduced economic investment. The image acquisition process and treatment of the information with mathematical support that it entails are described. The system involves an MS Kinect as a tool to create a radar that operates with the structured light principle to capture objects at a distance of less than 2 meters. The development of the scripts is done in the MATLAB software and in the same way the graphical interface that is presented to the user. As part of the initial tests of this prototype, the digitization of geometric shape structures has been performed with an accuracy of over 98%. This validates its efficient operation, which serves as the basis for the development of modeling in interior architecture for future work. © 2020, Springer Nature Switzerland AG.

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Inverse kinematics of a redundant manipulator robot using constrained optimization

2020 , Varela Aldas, José , Ayala-Chauvin, Manuel Ignacio , Andaluz, V.H. , Santamaría, M.

Redundant manipulative robots are characterized by greater manipulability improving performance but complicating inverse kinematics, on the other hand, optimization techniques allow solving complex problems in robotics applications with greater efficiency. This paper presents the inverse kinematics of a redundant manipulative robot with four degrees of freedom to track a desired trajectory, and considering constraint in manipulability. The optimization problem is proposed using the quadratic position errors of the operative end and the constraint is established by a manipulability index, for this the kinematic model of the robot is determined. The results show the points of singularity of the robot and the performance of the proposal implemented, observing the positional errors and the manipulability for each point of the trajectory. In addition, the optimization is evaluated for two desired manipulability values. Finally, it is concluded that the implemented method optimizes the inverse kinematics to track the desired path while constraining the manipulability. © Springer Nature Switzerland AG 2020.

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Virtual environment application that complements the treatment of dyslexia (VEATD) in children

2020 , Buele, Jorge , López, V.M. , Varela Aldas, José , Soria, A. , Palacios-Navarro, G.

The educational disorders that children present at an early age can cause them to not fully develop throughout their lives. In this research work a 3D virtual system that allows the child who has been diagnosed with dyslexia to complement the exercises performed in a conventional therapy is described. To achieve this an application was developed, the app consists of two games (each with three levels of difficulty), and that are part of the rehabilitation program. In each of these games virtual objects are combined with auditory messages to provide the user with an immersive experience, and to train more than one sense at a time. In the first game task, the activity asks the children to correctly locate the syllables that compose a word and for the second activity the children will listen to a word, after the games asks the children to select the correct word. This tool has been tested by a group of children (eight), with ages ranging from 8 to 12 years old, whose development can be supervised at home by their parents, since it is an intuitive and easy to use interface. The results obtained are stored in a database and in this way the medical specialist can monitor the progress of the child throughout his treatment. For the validation of this proposal the SUS usability test was used. © Springer Nature Switzerland AG 2020.

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Voltammetric Electronic Tongues Applied to Classify Sucrose Samples Through Multivariate Analysis

2021 , Fuentes, E.M. , Varela Aldas, José , Verdú S. , Meló R.G. , Alcañiz M.

The aim of the present study was to classify samples of sugar with different concentrations through a Voltammetric Electronic tongues (VET), with a generic pulse sequence consisted of 22 pulses ranging from –1000 mV to + 1000 mV with a duration of 20 ms/pulse over different samples such as 1.25mM, 2.5mM, 5mM and 10mM, of sucrose concentration, these were measured 4 times each concentration and the test was developed 4 times, giving a total number of 506.880 data supervised learning algorithm using support vector machine was employed, choosing a linear function as a classifying element. In the training, 75% of the data was used to determine the coefficients of the classification function, and the remaining (25%) was used to evaluate the performance of the proposal. The results showed a concordance of more than 80% in the separation of sample, allowing to conclude as acceptable the performance of the classifier and the data acquired through the voltammetric tongue. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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Modeling and Control of Omnidirectional Robots with Displaced Center of Mass

2022 , Gallo L.V. , Paste B.D. , Varela Aldas, José , Andaluz, Víctor H.

This work focuses on the design and implementation of a control algorithm for tracking trajectories of an omnidirectional robotic platform. The design is based on a dynamic model that considers the center of mass displaced; this model is obtained by formulating Euler–Lagrange considering the kinetic energy that acts on the robotic system. This type of model is used for when robots carry loads and these are not located in the center of the robot directly affecting the dynamics of the robotic platform; validation of the obtained model is carried out experimentally with an identification algorithm using the robotic platform built. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

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