Varela Aldas, José
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Varela Aldas, José
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Ambato
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josevarela@uti.edu.ec
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57192546163

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Effects of a dual intervention (motor and virtual reality-based cognitive) on cognition in patients with mild cognitive impairment: a single-blind, randomized controlled trial

2024 , Buele, Jorge , Avilés-Castillo, Fátima , Carolina Del-Valle-Soto , Varela Aldas, José , Guillermo Palacios-Navarro

Abstract Background The increase in cases of mild cognitive impairment (MCI) underlines the urgency of finding effective methods to slow its progression. Given the limited effectiveness of current pharmacological options to prevent or treat the early stages of this deterioration, non-pharmacological alternatives are especially relevant. Objective To assess the effectiveness of a cognitive-motor intervention based on immersive virtual reality (VR) that simulates an activity of daily living (ADL) on cognitive functions and its impact on depression and the ability to perform such activities in patients with MCI. Methods Thirty-four older adults (men, women) with MCI were randomized to the experimental group (n = 17; 75.41 ± 5.76) or control (n = 17; 77.35 ± 6.75) group. Both groups received motor training, through aerobic, balance and resistance activities in group. Subsequently, the experimental group received cognitive training based on VR, while the control group received traditional cognitive training. Cognitive functions, depression, and the ability to perform activities of daily living (ADLs) were assessed using the Spanish versions of the Montreal Cognitive Assessment (MoCA-S), the Short Geriatric Depression Scale (SGDS-S), and the of Instrumental Activities of Daily Living (IADL-S) before and after 6-week intervention (a total of twelve 40-minutes sessions). Results Between groups comparison did not reveal significant differences in either cognitive function or geriatric depression. The intragroup effect of cognitive function and geriatric depression was significant in both groups (p < 0.001), with large effect sizes. There was no statistically significant improvement in any of the groups when evaluating their performance in ADLs (control, p = 0.28; experimental, p = 0.46) as expected. The completion rate in the experimental group was higher (82.35%) compared to the control group (70.59%). Likewise, participants in the experimental group reached a higher level of difficulty in the application and needed less time to complete the task at each level. Conclusions The application of a dual intervention, through motor training prior to a cognitive task based on Immersive VR was shown to be a beneficial non-pharmacological strategy to improve cognitive functions and reduce depression in patients with MCI. Similarly, the control group benefited from such dual intervention with statistically significant improvements. Trial registration ClinicalTrials.gov NCT06313931; https://clinicaltrials.gov/study/NCT06313931.

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Movement Monitoring in Commercial Areas Using Internet of Things

2023 , Varela Aldas, José , Ruales, María Belén , Bastidas G.

The Internet of Things has been a trend in the last decade and is now found in countless applications, solving problems in almost any field. Specifically, in the commercial area, there is an effort to apply this technology to facilitate the control of services or processes. This work presents the movement monitoring of commercial areas. The proposal uses the ESP32 board that, using passive infrared sensors located perpendicular to each other, covers two areas of interest for commercial premises with multiple products. The collected data travel to the ThingSpeak Platform, where there are graphs with the states of the sensors, allowing identify the active area. The results present the motion state readings in the two areas, indicating the correct functioning of the system. Finally, we use a technology acceptance model to analyze this proposal, determining an acceptance of 69.6% that is not favorable for this proposal. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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Prototype of a Low Cost Turbine for the Generation of Clean Energy in the Ecuadorian Amazon

2020 , Guáitara B. , Buele, Jorge , Salazar F.W. , Varela Aldas, José

Access to electricity supply in remote areas is limited, despite having wealth of other natural resources such as water. This document presents the design and construction of a scale electric generation system, taking advantage of the hydraulic energy produced by a constant flow of water flow. For this, the turbine design is described, which is based on the principles of Francis and Kaplan. In addition, the structural design made in CAD/CAM software and the actual implementation of the system are shown. To determine the generated electric potential, the electromagnetic analysis is performed based on the Maxwell-Faraday equation and the respective calculations. The validation of this proposal is determined by conducting experimental tests with balanced, unbalanced, series and parallel coils and with their implementation in a home. © 2020, Springer Nature Switzerland AG.

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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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Dynamics of a Unicycle-Type Wheeled Mobile Manipulator Robot

2020 , Varela Aldas, José , Chicaiza, F.A. , Andaluz V.H.

Mathematical modeling is widely used in robotics to display behaviors and design control algorithms; the dynamic model of a robot describes the movements considering the action of internal and external forces of the system. This paper presents the dynamics of a unicycle mobile manipulator robot using the Euler-Lagrange proposal and conditioning the model to obtain the output velocities in the robot from the desired velocities. Additionally, the dynamic model is complemented by the identification of parameters using experimental data obtained from the AKASHA robot. The results present the signals applied in the identification, the values of the dynamic constants are found and the validation data which indicate a correct performance of the proposal are graphically shown. © 2020, Springer Nature Switzerland AG.

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Quadcopters Control Using Online Dynamic Mode Decomposition

2023 , Guevara B.S. , Recalde L.F. , Varela Aldas, José , Gandolfo D.C. , Toibero J.M.

Over the past few years, unmanned aerial vehicles (UAVs) have gained popularity in a wide range of applications such as delivery services, inspection, and monitoring. However, for these applications to be safe and efficient, an accurate model of the UAV's dynamic is essential. In this article, the authors propose a novel control system for the DJI Matrice 100 quadcopter based on the online dynamic mode decomposition with control (DMDc) algorithm and iterative optimal estimation techniques. The online DMDc algorithm enables the identification of the system's dynamic, a critical requirement for an adaptive control. By decomposing the quadcopter's system into dynamic modes, the authors create a precise model of the system's behavior using a Hardware in the Loop (HiL) framework, which is used to design the control system based on inverse dynamics. The adaptive control system can adjust its parameters based on changes in the system's behavior, making it suitable for UAV operations in unpredictable environments. These results demonstrate that the proposed control system significantly improves performance in the presence of disturbances.The research contributes to the field of UAV control and highlights the potential of DMD and adaptive control techniques for enhancing the safety and efficiency of UAV operations. Copyright © 2023 The Authors.

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Development of Behavior Profile of Users with Visual Impairment

2020 , Guevara Maldonado, César Byron , Arias Flores, Hugo Patricio , Varela Aldas, José , Castillo Salazar, David Ricardo , Borja M. , Fierro-Saltos W. , Rivera R. , Hidalgo-Guijarro J. , Yandún-Velasteguí M.

The interaction of the user with visual impairment with assistive technologies, and in particular with screen readers, generates a group of actions and events during their navigation. These interactions are defined as behavioral patterns, which have a sequence that occurs at specific time slot. Understanding user behavior by analyzing their interaction with applications, in addition, details the characteristics, relationships, structures and functions of the sequence of actions in a specific application domain. The objective of this document is to find activity patterns from a set of commands used by the user, combining data mining and a Bayesian model. This model calculates the probability of the functions used with the screen reader and generates a behavior profile to improve the user experience. For this study, the screen reader JAWS version 2018, the Open Journal Systems platform version 3.0.1 and a computer with Windows 10 operating system were used. During the first phase, command history used by the user by interacting with the Open Journal Systems platform were collected. The result is that the accessibility of users with visual impairment to interact with the computer and its applications has been improved by applying this model. © Springer Nature Switzerland AG 2020.

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Teleoperation of a mobile manipulator with feedback forces for evasion of obstacles [Teleoperación de un manipulador móvil con retroalimentación de fuerzas para evasión de obstáculos]

2019 , Andaluz V.H. , Varela Aldas, José , Chicaiza F.A. , Quevedo W.X. , Ruales, María Belén

This work develops the teleoperation of a mobile manipulator using a kinematic and dynamic control. In addition, the operator receives feedback forces through a haptic device to evade obstacles. The experiments were performed in a local wireless communication network and using the AKASHA robot. The results show an adequate following of the references of control, speed errors are corrected with minimum communication delays. © 2019, Associacao Iberica de Sistemas e Tecnologias de Informacao. All rights reserved.

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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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Virtual Environment for the Mashing and Boiling Process in Craft Beer Production

2023 , Pogo S.I. , Granizo J. , Andaluz V.H. , Varela Aldas, José

Process automation allows to increase production and improve the quality of craft products. This paper presents the implementation of closed-loop control algorithms for a mashing and brewing plant of craft beer. The proposed control scheme is implemented through the HIL technique, for which a virtual environment that simulates the behavior of the industrial process and a control card where the control algorithms are implemented are considered. To represent the behavior of the plant level and temperature processes, the mathematical model of each process is obtained, this model is used for the design of the control algo-rhythms, and the plant is modeled in 3D and incorporated into the graphics engine also has effects of realism together with been 3D in order to increase the level of realism to the process. For user interaction with the environment, an HMI type mantle center is incorporated to visualize and control the process manually, semi-automatically, and automatically, in order to test the control algorithms safely and avoid the risk of instrumentation damage or loss of real materials. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

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