Otniel Portillo-Rodríguez - Profile on Academia.edu (original) (raw)

Papers by Otniel Portillo-Rodríguez

Super Twisting Sliding Mode Control for the Maximum Power Point Tracking in a Photovoltaic System under Partial Shading

Memorias del Congreso Nacional de Control Automático

One of the most popular renewable energy sources is photovoltaic energy; however, its main drawba... more One of the most popular renewable energy sources is photovoltaic energy; however, its main drawback is the low conversion efficiency. Optimal system operation requires efficient tracking of the maximum power point representing the maximum energy that can be extracted from the photovoltaic system. One of the main problems is the presence of partial shadows. In this scenario, the system's power presents multiple peaks; a robust control technique is required to properly track the Global Maximum Power Point (GMPP). This paper proposes using a Sliding Mode Controller (SMC) for the GMPP tracking which is a robust strategy for coping with changing environmental conditions and partial shadows. Numerical simulation results show the effectiveness of the proposal.

A Study of the Physical Characteristics and Defects of Green Coffee Beans That Influence the Sensory Notes Using Machine Learning Models

Processes, Dec 19, 2023

Empirical Analysis on the Effectiveness of Pre-trained Models in the Identification of Physical Violence Against Women in Videos for a Multi-class Approach

Communications in computer and information science, 2024

Lecture Notes in Computer Science, Sep 14, 2008

This paper presents a multimodal system capable to understand and correct in real-time the moveme... more This paper presents a multimodal system capable to understand and correct in real-time the movements of Tai-Chi students through the integration of audiovisual -tactile technologies. This platform acts like a virtual teacher that transfers the knowledge of five Tai-Chi movements using feedback stimuli to compensate the errors committed by a user during the performance of the gesture. The fundamental components of this multimodal interface are the gesture recognition system (using k-means clustering, Probabilistic Neural Networks (PNN) and Finite State Machines (FSM)) and the real-time descriptor of motion which is used to compute and qualify the actual movements performed by the student respect to the movements performed by the master, obtaining several feedbacks and compensating this movement in real-time varying audiovisual -tactile parameters of different devices. The experiments of this multimodal platform have confirmed that the quality of the movements performed by the students is improved significantly.

Maximum power point tracking techniques in photovoltaic systems: A brief review

The use of photovoltaic (PV) systems is increasingly growing in importance since they involve an ... more The use of photovoltaic (PV) systems is increasingly growing in importance since they involve an exploitation of solar radiation constituting an energy source which is renewable, available in most places, and pollution-free. Despite their numerous advantages, PV systems have two major drawbacks: low energy conversion efficiency and loss of energy due to variations in meteorological conditions; for this reason, Maximum Power Point Tracking (MPPT) control techniques play a key role in exploiting the maximum energy caught by PV modules. This paper presents a brief review of the main MPPT strategies: general characteristics, advantages, and drawbacks of the proposed methods are discussed.

Medición inalámbrica de humedad relativa y temperatura para estrategias de monitoreo puntual y distribuido

inalámbrica de humedad relativa y temperatura para estrategias de monitoreo puntual y distribuido... more inalámbrica de humedad relativa y temperatura para estrategias de monitoreo puntual y distribuido. Abstract—En este artículo se presenta un sistema de monitoreo distribuido por comunicación inalámbrica que permite medir de forma puntual los gradientes de temperatura y humedad relativa en diferentes puntos dentro de un volumen o área especifico donde se almacenan productos agrícolas tales como: cacao, café, tabaco o azúcar. El sistema completo se compone principalmente de instrumentos de medición, un receptor inalámbrico y una interfaz para la administración y manejo de datos provenientes de la distribución de los instrumentos, esto debido a la capacidad de escalabilidad que presenta dicho sistema.

Modular robots for minimally invasive surgery

Mango instrumentado para la medición de fuerza máxima sostenida de la mano

The establishment of heterotic groups and heterotic patterns is crucial to a successful maize hyb... more The establishment of heterotic groups and heterotic patterns is crucial to a successful maize hybrid breeding programme. Molecular markers can be used for differentiating maize into heterotic groups which can be used for maximum exploitation of heterosis. A core set of 45 maize inbred lines was selected from 96 maize inbred lines that were obtained from major breeding programmes in Zambia, Zimbabwe, CIMMYT, IITA, and USA. The 45 in- bred lines were assessed for their genetic diversity and assigned to different heterotic groups using 129SNPs. The genetic distance ranged from 0.03 to 0.99, with the highest distance observed between inbred lines B73 and Mo17 and the least between L3233 and N3. The inbred lines were clustered into four groups which corresponded to the N, SC, BSS, and Lancaster heterotic groups. The genetic divergence among temperate inbred lines was larger than that among tropical inbred lines. Temperate inbred lines with potential to improve the heterotic response of t...

Gaceta medica de Mexico, 2018

En el Estado de México no existen investigaciones que proporcionen información para toma de decis... more En el Estado de México no existen investigaciones que proporcionen información para toma de decisiones y administración de recursos relacionados con la atención de las lesiones por causa externa (LCE). Describir las LCE en un servicio de urgencias durante un periodo de cinco años. Se diseñó un estudio retrospectivo con pacientes que ingresaron al servicio de urgencias (2010-2015) por diagnóstico de LCE. Se realizó análisis descriptivo y de clúster. En el servicio de urgencias, 16.59 % de las atenciones derivaron de LCE. Se incluyeron 16 567 pacientes de 14 a 99 años (media o promedio = 37.7, DE = 17.28), 69.2 % fue del sexo masculino. Las LCE principalmente ocurrieron en la vía pública (26.3 %) y en el hogar (23.7 %). Las causas más frecuentes fueron agresiones fuera del hogar (32.7 %), en promedio a los 34 años; caídas (25 %) en promedio a los 45 años; accidentes ocasionados por vehículos de motor (9.7 %), en promedio a los 33 años. El análisis por clúster identificó cuatro grupos:...

2016 13th International Conference on Power Electronics (CIEP), 2016

This document presents the design and construction of a plasma generator for electrosurgical appl... more This document presents the design and construction of a plasma generator for electrosurgical applications. The generator is comprised of four main parts: DC power supply, topology push-pull, controller unit and plasma probe. First results generating plasma by repetitively-pulsed electrical discharges in sodium chloride saline solution are reported.

Diseño y desarrollo de un sistema vibrotáctil utilizado en un robot planar para la rehabilitación de las extremidades superiores

ABSTRACT En este artículo se presenta el diseño y desarrollo de un sistema vibrotáctil implementa... more ABSTRACT En este artículo se presenta el diseño y desarrollo de un sistema vibrotáctil implementado en un robot planar con 3 grados de libertad teniendo como fin rehabilitar las extremidades superiores de un paciente y proporcionarle estímulos hápticos. Este sistema obtiene información de las posiciones que realizan los pacientes durante su rehabilitación para que el fisioterapeuta pueda utilizar dicha información la cual es de vital importancia en áreas como la rehabilitación y transferencia de habilidades. Este sistema también ofrece el poder acelerar procesos neuroplásticos al mismo tiempo de ser un sistema de bajo costo.

Spatial Sound and Frequency Distortion for Enactive Transfer of Skills in Tai-Chi Movements to Visual Impaired People

A novel methodology for Enactive Skills Transmission of Tai Chi movements through sound feed-back... more A novel methodology for Enactive Skills Transmission of Tai Chi movements through sound feed-back stimuli is presented in this paper. We adopted the paradigm of spatial sound and frequency distortion as an accurate methodology for the transmission of error-feedback to the user. An intelligent system based on Gesture recognition methodologies and a real-time motion descriptor system is applied to engage and guide the users to perform an unknown movement in a natural and transparent process using the sound like the base of the transfer of the skill.

A Low-Cost Gesture Recognition System for Rehabilitation and Movement Assessment

Autonomous System of Inspection and Control for Aluminium Fuel Injectors

En este trabajo se presenta un sistema electrónico, basado en la medición de la distribución del ... more En este trabajo se presenta un sistema electrónico, basado en la medición de la distribución del peso en los pies, cuyo objetivo es coadyuvar en la evaluación postural. La evaluación postural utilizada por los fisioterapeutas para corregir problemas musculo-esqueléticos derivados por la edad, accidentes, enfermedades, etc. El sistema electrónico construido se validó preliminarmente utilizando videocámaras para corroborar la postura en un sujeto. Con los datos obtenidos se pudo confirmar que el sistema propuesto es capaz de ayudar en la corrección de la postura en tiempo real. La limitación principal de este trabajo es el reducido número de pruebas, por lo que sólo se presentan resultados preliminares. La originalidad de este trabajo reside principalmente en la solución propuesta para evaluar y corregir la postura por medio de un sistema electrónico, novedoso por el método empleado y su portabilidad. Derivado de los resultados presentados se puede concluir que sistema propuesto es capaz de ayudar a corregir la postura en tiempo real.

Portable electronic device to assess the human balance using a minimum number of sensors

OBJECTIVE This paper presents the design and development of a new electronic portable device to a... more OBJECTIVE This paper presents the design and development of a new electronic portable device to assess the human balance of the human body during standing, using a minimal number of sensors and peripheral components. This device is aimed to evaluate human balance in environments outside of specialized laboratories, such as small clinics and therapy offices. APPROACH The design is based on previous designs using three or more resistive force sensors attached to the feet, however in the present work, the sensors were attached on an adjustable platform, to fit several sizes of feet. Furthermore, all the signal acquisition, process, storage and display are executed by an embedded electronic system, thus avoiding the use of computers and external peripherals. A new method to compute the CoP using only two sensors per foot was developed and tested in a group of 50 university students, (17 women and 33 men), 26.04 ± 4.94 years. MAIN RESULTS It was developed a portable electronic system to ...

Introduction to the Proceedings of IMIASH'12

A novel model to quantify balance alterations in older adults based on the center of pressure (CoP) measurements with a cross-sectional study

Background The timely detection of fall risk or balance impairment in older adults is transcenden... more Background The timely detection of fall risk or balance impairment in older adults is transcendental because, based on a reliable diagnosis, clinical actions can be taken to prevent accidents. This study presents a statistical model to estimate the fall risk from the center of pressure (CoP) data. Methods This study is a cross-sectional analysis from a cohort of community-dwelling older adults aged 60 and over living in Mexico City. CoP balance assessments were conducted in 414 older adults (72.2% females) with a mean age of 70.23 ± 6.68, using a modified and previously validated Wii Balance Board (MWBB) platform. From this information, 78 CoP indexes were calculated and analyzed. Multiple logistic regression models were fitted in order to estimate the relationship between balance alteration and the CoP indexes and other covariables. Results The CoP velocity index in the Antero-Posterior direction with open eyes (MVELAPOE) had the best value of area under the curve (AUC) to identify...