JUAN PRADO OLIVAREZ - Academia.edu (original) (raw)
Papers by JUAN PRADO OLIVAREZ
IEEE Access
This work aims to classify malaria infected red blood cells from those uninfected using two deep ... more This work aims to classify malaria infected red blood cells from those uninfected using two deep learning approaches. Plasmodium parasite transmitted by a female anopheles's mosquitoes bite is the main cause of malaria. Commonly, Microbiological analyses by a microscope allows detecting cells infected from a blood sample, followed by a specialist interpretation of results to conclude the diagnosis process. Taking advantage of efficient deep learning approaches applied in computer vision field, the present framework proposes two deep learning architecture based on Convolutional-Recurrent neural Networks to detect accurately malaria infected cells. The first one implements a Convolutional Long Short-Term Memory while the second uses a Convolutional Bidirectional Long Short-Term Memory architecture. A malaria's public dataset consisting of parasitized and uninfected red blood cell images was used for training and testing the proposed models. The methods developed in this work achieved an accuracy of 99.89 % in the detection of malaria-infected red blood cells, without preprocessing data. 12 13 14 Malaria is caused by the bites of female Anopheles 15 mosquitoes infected with protozoan parasites. Malaria is 16 essentially a tropical disease since mosquitoes are produced 17 in large numbers in humid environments. Recent global statis-18 tics illustrate some 229 million cases of malaria, with 1,700 19 deaths per day, of which 96% lived in Africa [1]. The most 20 affected by malaria are children under 5 years old, whom 21 represents an 80 % mortality rate in the region according 22 to [1]. 23 Among other malaria pathogens, the Plasmodium falci-24 parum and Plasmodium vivax attack human red blood cells 25 288 corner. On the diagonal, the TPR is equal to the FPR, given 289 a random classifier. The area under the ROC curve (AUC), 290 directly linked to the accuracy metric, calculates the classi-291 fier's performance in discriminating between parasitized and 292 uninfected cells. 293 In the case of 28 × 28 image size, 99.72 % of cell 294 images were correctly detected as parasitized against 99.40 % 295 for uninfected cell images. 99.65 % of samples were accu-296 rately diagnosed as parasitized in contrast to 99.78 % 297 for uninfected cells considering the 32 × 32 image size. 298 According to the Figure 7(e) where 64 × 64 samples were 299 used, parasitized and uninfected cells got close predic-300 tions of 99.79 % and 99.78 % comparing with their true 301 labels. Finally, the CNN-LSTM classifier correctly predicted 302 99.86 % as parasitized and 99.63 % of 96 × 96 samples as 303 uninfected.
Energies, 2022
Local path planning is a key task for the motion planners of autonomous vehicles since it command... more Local path planning is a key task for the motion planners of autonomous vehicles since it commands the vehicle across its environment while avoiding any obstacles. To perform this task, the local path planner generates a trajectory and a velocity profile, which are then sent to the vehicle’s actuators. This paper proposes a new local path planner for autonomous vehicles based on the Attractor Dynamic Approach (ADA), which was inspired by the behavior of movement of living beings, along with an algorithm that takes into account four acceleration policies, the ST dynamic vehicle model, and several constraints regarding the comfort and security. The original functions that define the ADA were modified in order to adapt it to the non-holonomic vehicle’s constraints and to improve its response when an impact scenario is detected. The present approach is validated in a well-known simulator for autonomous vehicles under three representative cases of study where the vehicle was capable of g...
Sensors, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
2021 44th International Conference on Telecommunications and Signal Processing (TSP), 2021
Communication standards commonly used in microgrids monitoring and control systems often have cov... more Communication standards commonly used in microgrids monitoring and control systems often have coverage limitations. Typically this require both the human operator and the computer equipment to be physically on site. This research aims to develop a monitoring and control system for DC microgrids that uses external computer equipment and can be accessed remotely. The proposed system is based on Internet of Things (IoT) and Controller Area Network (CAN) technologies. It uses computational resources hosted in the cloud to perform monitoring and control tasks and provides human operators with a web interface to access the system through an Internet connection. The proposed system is validated through a case study of a DC microgrid. The obtained results show that it is possible to extend the coverage and capabilities of monitoring and control systems for DC microgrids with IoT services.
Pistas Educativas, Nov 29, 2020
Micromachines, 2022
Impedance measuring acquisition systems focused on breast tumor detection, as well as image proce... more Impedance measuring acquisition systems focused on breast tumor detection, as well as image processing techniques for 3D imaging, are reviewed in this paper in order to define potential opportunity areas for future research. The description of reported works using electrical impedance tomography (EIT)-based techniques and methodologies for 3D bioimpedance imaging of breast tissues with tumors is presented. The review is based on searching and analyzing related works reported in the most important research databases and is structured according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) parameters and statements. Nineteen papers reporting breast tumor detection and location using EIT were systematically selected and analyzed in this review. Clinical trials in the experimental stage did not produce results in most of analyzed proposals (about 80%), wherein statistical criteria comparison was not possible, such as specificity, sensitivity and pred...
Sensors, 2022
The interruption of rehabilitation activities caused by the COVID-19 lockdown has significant hea... more The interruption of rehabilitation activities caused by the COVID-19 lockdown has significant health negative consequences for the population with physical disabilities. Thus, measuring the range of motion (ROM) using remotely taken photographs, which are then sent to specialists for formal assessment, has been recommended. Currently, low-cost Kinect motion capture sensors with a natural user interface are the most feasible implementations for upper limb motion analysis. An active range of motion (AROM) measuring system based on a Kinect v2 sensor for upper limb motion analysis using Fugl-Meyer Assessment (FMA) scoring is described in this paper. Two test groups of children, each having eighteen participants, were analyzed in the experimental stage, where upper limbs’ AROM and motor performance were assessed using FMA. Participants in the control group (mean age of 7.83 ± 2.54 years) had no cognitive impairment or upper limb musculoskeletal problems. The study test group comprised c...
Micromachines, 2022
In power electronics, magnetic components are fundamental, and, unfortunately, represent one of t... more In power electronics, magnetic components are fundamental, and, unfortunately, represent one of the greatest challenges for designers because they are some of the components that lead the opposition to miniaturization and the main source of losses (both electrical and thermal). The use of ferromagnetic materials as substitutes for ferrite, in the core of magnetic components, has been proposed as a solution to this problem, and with them, a new perspective and methodology in the calculation of power losses open the way to new design proposals and challenges to overcome. Achieving a core losses model that combines all the parameters (electric, magnetic, thermal) needed in power electronic applications is a challenge. The main objective of this work is to position the reader in state-of-the-art for core losses models. This last provides, in one source, tools and techniques to develop magnetic solutions towards miniaturization applications. Details about new proposals, materials used, d...
2021 IEEE International Autumn Meeting on Power, Electronics and Computing (ROPEC), 2021
There are various methods and equipment for the measurement of greenhouse variables with IoT, how... more There are various methods and equipment for the measurement of greenhouse variables with IoT, however, most of them have disadvantages such as expensiveness, limited coverage, or lack updating capacity through new technologies. Hence, this article aims to explain the development of a greenhouse variable measurement system, whose magnitudes will be recorded in a database to later be accessed from a device connected to the internet, with the possibility of reconfiguring it in order to measure other variables, and/or adapt it to other sensors and/or applications. A methodology for the use of a FPGA based data acquisition and processing card, in addition to a Raspberry-Pi IoT system are described, with which communication will be established with the following measurement sensors: TMP006 (infrared, IR, temperature), TSL230 (solar radiation), SHT75 (air temperature and relative humidity), and FC-28 (soil humidity). This system will not only allow real-time in situ acquisition and processing, but also will store the information gathered in a database located on local and external servers using open-source code. The system includes both IoT and in situ interfaces. Communication protocols are used to measure the variables. Statistical tests were performed for the monitored data, verifying its accuracy. The sensors' performance reached correlations over r=0.9r=0.9r=0.9 in most of the cases. Lower correlations and significant measurement errors depend specifically on the selected sensor.
Nova Scientia, 2020
Introduction : The electrical impedance measurement and characterization of biological tissues al... more Introduction : The electrical impedance measurement and characterization of biological tissues allow to distinguish between a healthy and pathological tissues. The use of techniques such as electrical impedance tomography is widely used in clinical testing through various applications. In this work the Linear Back Projection (LBP) method is employed to reconstruct images from electrical impedance measurements in order to obtain the location of carcinoma emulator previously inserted within female-breast-shaped agar-agar models. Method : A ring arrangement of eight electrodes was used for measuring the impedance on the seven female-breast-shaped agar-agar models. A cross section of a healthy female breast (without emulators) corresponding to the measurement plane of the ring electrode arrangement was designed and simulated in the COMSOL software. The sensitivity maps of each pair of electrodes along the impedance measurement were computed using the conductivity distribution data obtai...
2020 IEEE International Autumn Meeting on Power, Electronics and Computing (ROPEC), 2020
Titanium dioxide (chemical formula TiO2) is a semiconductor that absorbs electromagnetic radiatio... more Titanium dioxide (chemical formula TiO2) is a semiconductor that absorbs electromagnetic radiation in the UV region; according to the type of crystallization, different crystalline distributions will be formed (anatase, rutile and brookite) which have significant differences in their chemical, mechanical and electrical properties; the last mentioned property is currently a little-known field of research, however TiO2 is the most widely used photocatalyst and it is currently used to degrade various types of pollutants in the medium. In this paper, a methodology is designed and implemented to know the electrical behavior of anatase, rutile and brookite crystalline structures; the study is developed from the simulation in Comsol Multiphysic software; measurements of electrical properties are made with the technique of electrical impedance spectroscopy in a measurement frequency range of 4Hz to 8MHz. During the process, the particular geometric constants for this investigation are obtai...
Sensors, 2021
Quantifying the quality of upper limb movements is fundamental to the therapeutic process of pati... more Quantifying the quality of upper limb movements is fundamental to the therapeutic process of patients with cerebral palsy (CP). Several clinical methods are currently available to assess the upper limb range of motion (ROM) in children with CP. This paper focuses on identifying and describing available techniques for the quantitative assessment of the upper limb active range of motion (AROM) and kinematics in children with CP. Following the screening and exclusion of articles that did not meet the selection criteria, we analyzed 14 studies involving objective upper extremity assessments of the AROM and kinematics using optoelectronic devices, wearable sensors, and low-cost Kinect sensors in children with CP aged 4–18 years. An increase in the motor function of the upper extremity and an improvement in most of the daily tasks reviewed were reported. In the population of this study, the potential of wearable sensors and the Kinect sensor natural user interface as complementary devices...
El presente articulo describe el diseno, desarrollo y resultados obtenidos de un sistema propuest... more El presente articulo describe el diseno, desarrollo y resultados obtenidos de un sistema propuesto de medicion de bioimpedancia electrica. Para ello el articulo incluye una revision de las propiedades electricas de los tejidos biologicos, asi como la definicion de bioimpedancia electrica. El sistema esta basado tanto en un acondicionamiento de las senales asi como en un procesamiento digital llevado a cabo mediante un procesador digital de senales, el calculo del valor de la impedancia compleja se realiza mediante un algoritmo propuesto. Con rango de frecuencias en la medicion de la bioimpedancia de 500Hz hasta 10KHz, suficiente para caracterizar el comportamiento electrico de algunos tejidos biologicos incluido la piel humana. De acuerdo a los resultados obtenidos el prototipo resultante representa una solucion economicamente viable y completamente funcionalen aplicaciones portatiles.
Resumen En este articulo se presenta una metodologia eficaz y de bajo costo para determinar la pr... more Resumen En este articulo se presenta una metodologia eficaz y de bajo costo para determinar la presion intraocular (PIO) a partir de la medicion de impedancia electrica compleja en un rango de frecuencias especifico. El aumento en la PIO generado por el exceso de fluido en el cuerpo vitreo, dana el nervio optico, este aumento es propiciado por el glaucoma. La propuesta de este trabajo es relacionar la medicion de la impedancia electrica compleja con la PIO. La variacion de la PIO se logra inyectando una solucion oftalmica al globo ocular. En la experimentacion se utilizo tejido ex vivo de muestras porcinas y a su vez un tonometro para medir directamente la PIO. Los cambios de presion en el ojo modifican la magnitud de la impedancia electrica compleja que es registrada para analizar la relacion con la PIO. Tambien se discute la ubicacion y geometria de los electrodos de medicion. Palabra(s) Clave: Bioimpedancia, Espectroiscopia, Glaucoma. Abstract This article presents an effective a...
En este trabajo se presenta de forma breve la simulacion realizada (en un software especializado ... more En este trabajo se presenta de forma breve la simulacion realizada (en un software especializado de simulacion multifisica llamado COMSOL), con una metodologia que tiene la finalidad de ubicar tejido patologico dentro de una mama femenina. El objetivo es obtener un parametro visual con el cual se puedan comparar los resultados numericos obtenidos por el analisis de bioimpedancia y por consiguiente indicar el area donde posiblemente se encuentre un carcinoma. Para ello se utilizo un arreglo de 12 electrodos, siendo uno de ellos el electrodo pivote, al cual se le aplicara un voltaje a cierta frecuencia y mediante un barrido se obtiene la corriente para un par de electrodos con la cual se determinara la impedancia correspondiente
Journal of Real-Time Image Processing, 2020
Convolutional Neural Networks (CNN) have become one of the best algorithms in machine learning fo... more Convolutional Neural Networks (CNN) have become one of the best algorithms in machine learning for content classification of digital images. The CNN computational complexity is much larger than traditional algorithms, that is why the use of Graphical Processor Units (GPU) and online servers to achieve operations acceleration is a common solution. However, there is a growing demand for real-time processing solutions in the object recognition field mainly implemented on embedded systems, which are limited both in resources and energy consumption. Recently, reported works are focused on minimizing the required resources through two design strategies. The first one is by implementing one accelerator that can be adapted to the operations of the whole CNN. The CNN architecture proposals with one accelerator for each convolution layer belong to the second design strategy, where higher performance is achieved in multiple image processing. A new design strategy is proposed in this paper, which is based on multiple accelerators using a layer operation chaining scheme for computing in parallel the operations corresponding to multiple CNN layers. Three types of parallel data processing are adopted in the proposed architecture, where the parallelism level for convolution layers is determined by defined cost-function-based algorithms. The proposed design strategy is shown by implementing three naive CNNs on a De2i-150 board, in which a peak acceleration of 18.04x was achieved in contrast with state-of-the-art design methods without layer operation chaining. Furthermore, the design results of one modified Alexnet CNN were obtained. According to the obtained results, the proposed design strategy allows to achieve a smaller processing time than that obtained by reported works using the other two design strategies. In addition, a competitive result in resources utilization is obtained for naive CNNs.
IEICE Electronics Express, 2019
Convolutional Neuronal Networks (CNN) implementation on embedded devices is restricted due to the... more Convolutional Neuronal Networks (CNN) implementation on embedded devices is restricted due to the number of layers of some CNN models. In this context, this paper describes a novel architecture based on Layer Operation Chaining (LOC) which uses fewer convolvers than convolution layers. A reutilization of hardware convolvers is promoted through kernel decomposition. Thus, an architectural design with reduced resources utilization is achieved, suitable to be implemented on low-end devices as a solution for portable classification applications. Experimental results show that the proposed design has a competitive processing time and overcomes resource utilization when compared with state-of-the-art related works.
Http Www Theses Fr, 2006
La conception et la realisation d'un microsysteme par spectroscopie de bioimpedance basee sur... more La conception et la realisation d'un microsysteme par spectroscopie de bioimpedance basee sur la technique du pont auto accorde dans la bande [100 Hz – 1MHz] a ete developpee. Le premier chapitre traite du contexte et des techniques de la mesure d'impedance de tissus biologiques (bioimpedance), ainsi que les parametres d'influence sur la mesure. Le second chapitre introduit la modelisation de la cellule de mesure avec des microelectrodes coplanaires en 2D et 3D, ainsi que l'analyse theorique permettant le calcul des proprietes dielectriques de tissus. On a utilise le logiciel Femlab pour effectuer la simulation. Le troisieme chapitre decrit la fabrication de la cellule de mesure par les techniques lithographiques, la problematique de l'interface – electrolyte et le circuit equivalent de l'impedance de polarisation. Celui-ci suggere une chaine de mesure pour la spectroscopie de bioimpedance. Le dernier chapitre de la these presentee validation experimentale de la chaine de mesure realisee, on a determinee la valeur de l'impedance complexe directement et indirectement et se retrouve les valeurs de la permittivite et conductivite. Les mesures sont effectuees sur une serum physiologique et du sang (animal et humaine), finalement tous les resultats experimentaux sont presentes et discutes.
Sensors, 2014
Nitrogen plays a key role in crop yields. Hence, farmers may apply excessive N fertilizers to cro... more Nitrogen plays a key role in crop yields. Hence, farmers may apply excessive N fertilizers to crop fields, inducing environmental pollution. Crop N monitoring methods have been developed to improve N fertilizer management, most of them based on leaf or canopy optical-property measurements. However, sensitivity to environmental interference remains an important drawback. Electrical impedance has been applied to determine the physiological and nutritional status of plant tissue, but no studies related to plant-N contents are reported. The objective of this article is to analyze how the electrical impedance response of plants is affected by their N status. Four sets of lettuce (Lactuca sativa L.) with a different N-source concentrations per set were used. Total nitrogen and electrical impedance spectra (in a 1 to 100 kHz frequency range) were measured five times per set, three times every other day. Minimum phase angles of impedance spectra were detected and analyzed, together with the frequency value in which they occurred, and their magnitude at that frequency. High and positive correlation was observed between plant N content and frequency values at minimum phase angle with no significant variations
Biosystems Engineering: Biofactories for Food Production in the Century XXI, 2014
ABSTRACT Nowadays, there exist several threats around the world that cause catastrophic damages t... more ABSTRACT Nowadays, there exist several threats around the world that cause catastrophic damages to the planet. One of the most important menaces is the lack of food that affects the health of people around the world. Animals and plants need food to survive, the survival insurance of both will help to ensure the food production and by consequence the aliment for each person around the world, which is a priority issue in all countries. At the present time, the food production has been affected more drastically by several biotic and abiotic factors that day by day diminish the quantity and quality of the worldwide food; this menaces the food security, principally in less developed countries.
IEEE Access
This work aims to classify malaria infected red blood cells from those uninfected using two deep ... more This work aims to classify malaria infected red blood cells from those uninfected using two deep learning approaches. Plasmodium parasite transmitted by a female anopheles's mosquitoes bite is the main cause of malaria. Commonly, Microbiological analyses by a microscope allows detecting cells infected from a blood sample, followed by a specialist interpretation of results to conclude the diagnosis process. Taking advantage of efficient deep learning approaches applied in computer vision field, the present framework proposes two deep learning architecture based on Convolutional-Recurrent neural Networks to detect accurately malaria infected cells. The first one implements a Convolutional Long Short-Term Memory while the second uses a Convolutional Bidirectional Long Short-Term Memory architecture. A malaria's public dataset consisting of parasitized and uninfected red blood cell images was used for training and testing the proposed models. The methods developed in this work achieved an accuracy of 99.89 % in the detection of malaria-infected red blood cells, without preprocessing data. 12 13 14 Malaria is caused by the bites of female Anopheles 15 mosquitoes infected with protozoan parasites. Malaria is 16 essentially a tropical disease since mosquitoes are produced 17 in large numbers in humid environments. Recent global statis-18 tics illustrate some 229 million cases of malaria, with 1,700 19 deaths per day, of which 96% lived in Africa [1]. The most 20 affected by malaria are children under 5 years old, whom 21 represents an 80 % mortality rate in the region according 22 to [1]. 23 Among other malaria pathogens, the Plasmodium falci-24 parum and Plasmodium vivax attack human red blood cells 25 288 corner. On the diagonal, the TPR is equal to the FPR, given 289 a random classifier. The area under the ROC curve (AUC), 290 directly linked to the accuracy metric, calculates the classi-291 fier's performance in discriminating between parasitized and 292 uninfected cells. 293 In the case of 28 × 28 image size, 99.72 % of cell 294 images were correctly detected as parasitized against 99.40 % 295 for uninfected cell images. 99.65 % of samples were accu-296 rately diagnosed as parasitized in contrast to 99.78 % 297 for uninfected cells considering the 32 × 32 image size. 298 According to the Figure 7(e) where 64 × 64 samples were 299 used, parasitized and uninfected cells got close predic-300 tions of 99.79 % and 99.78 % comparing with their true 301 labels. Finally, the CNN-LSTM classifier correctly predicted 302 99.86 % as parasitized and 99.63 % of 96 × 96 samples as 303 uninfected.
Energies, 2022
Local path planning is a key task for the motion planners of autonomous vehicles since it command... more Local path planning is a key task for the motion planners of autonomous vehicles since it commands the vehicle across its environment while avoiding any obstacles. To perform this task, the local path planner generates a trajectory and a velocity profile, which are then sent to the vehicle’s actuators. This paper proposes a new local path planner for autonomous vehicles based on the Attractor Dynamic Approach (ADA), which was inspired by the behavior of movement of living beings, along with an algorithm that takes into account four acceleration policies, the ST dynamic vehicle model, and several constraints regarding the comfort and security. The original functions that define the ADA were modified in order to adapt it to the non-holonomic vehicle’s constraints and to improve its response when an impact scenario is detected. The present approach is validated in a well-known simulator for autonomous vehicles under three representative cases of study where the vehicle was capable of g...
Sensors, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
2021 44th International Conference on Telecommunications and Signal Processing (TSP), 2021
Communication standards commonly used in microgrids monitoring and control systems often have cov... more Communication standards commonly used in microgrids monitoring and control systems often have coverage limitations. Typically this require both the human operator and the computer equipment to be physically on site. This research aims to develop a monitoring and control system for DC microgrids that uses external computer equipment and can be accessed remotely. The proposed system is based on Internet of Things (IoT) and Controller Area Network (CAN) technologies. It uses computational resources hosted in the cloud to perform monitoring and control tasks and provides human operators with a web interface to access the system through an Internet connection. The proposed system is validated through a case study of a DC microgrid. The obtained results show that it is possible to extend the coverage and capabilities of monitoring and control systems for DC microgrids with IoT services.
Pistas Educativas, Nov 29, 2020
Micromachines, 2022
Impedance measuring acquisition systems focused on breast tumor detection, as well as image proce... more Impedance measuring acquisition systems focused on breast tumor detection, as well as image processing techniques for 3D imaging, are reviewed in this paper in order to define potential opportunity areas for future research. The description of reported works using electrical impedance tomography (EIT)-based techniques and methodologies for 3D bioimpedance imaging of breast tissues with tumors is presented. The review is based on searching and analyzing related works reported in the most important research databases and is structured according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) parameters and statements. Nineteen papers reporting breast tumor detection and location using EIT were systematically selected and analyzed in this review. Clinical trials in the experimental stage did not produce results in most of analyzed proposals (about 80%), wherein statistical criteria comparison was not possible, such as specificity, sensitivity and pred...
Sensors, 2022
The interruption of rehabilitation activities caused by the COVID-19 lockdown has significant hea... more The interruption of rehabilitation activities caused by the COVID-19 lockdown has significant health negative consequences for the population with physical disabilities. Thus, measuring the range of motion (ROM) using remotely taken photographs, which are then sent to specialists for formal assessment, has been recommended. Currently, low-cost Kinect motion capture sensors with a natural user interface are the most feasible implementations for upper limb motion analysis. An active range of motion (AROM) measuring system based on a Kinect v2 sensor for upper limb motion analysis using Fugl-Meyer Assessment (FMA) scoring is described in this paper. Two test groups of children, each having eighteen participants, were analyzed in the experimental stage, where upper limbs’ AROM and motor performance were assessed using FMA. Participants in the control group (mean age of 7.83 ± 2.54 years) had no cognitive impairment or upper limb musculoskeletal problems. The study test group comprised c...
Micromachines, 2022
In power electronics, magnetic components are fundamental, and, unfortunately, represent one of t... more In power electronics, magnetic components are fundamental, and, unfortunately, represent one of the greatest challenges for designers because they are some of the components that lead the opposition to miniaturization and the main source of losses (both electrical and thermal). The use of ferromagnetic materials as substitutes for ferrite, in the core of magnetic components, has been proposed as a solution to this problem, and with them, a new perspective and methodology in the calculation of power losses open the way to new design proposals and challenges to overcome. Achieving a core losses model that combines all the parameters (electric, magnetic, thermal) needed in power electronic applications is a challenge. The main objective of this work is to position the reader in state-of-the-art for core losses models. This last provides, in one source, tools and techniques to develop magnetic solutions towards miniaturization applications. Details about new proposals, materials used, d...
2021 IEEE International Autumn Meeting on Power, Electronics and Computing (ROPEC), 2021
There are various methods and equipment for the measurement of greenhouse variables with IoT, how... more There are various methods and equipment for the measurement of greenhouse variables with IoT, however, most of them have disadvantages such as expensiveness, limited coverage, or lack updating capacity through new technologies. Hence, this article aims to explain the development of a greenhouse variable measurement system, whose magnitudes will be recorded in a database to later be accessed from a device connected to the internet, with the possibility of reconfiguring it in order to measure other variables, and/or adapt it to other sensors and/or applications. A methodology for the use of a FPGA based data acquisition and processing card, in addition to a Raspberry-Pi IoT system are described, with which communication will be established with the following measurement sensors: TMP006 (infrared, IR, temperature), TSL230 (solar radiation), SHT75 (air temperature and relative humidity), and FC-28 (soil humidity). This system will not only allow real-time in situ acquisition and processing, but also will store the information gathered in a database located on local and external servers using open-source code. The system includes both IoT and in situ interfaces. Communication protocols are used to measure the variables. Statistical tests were performed for the monitored data, verifying its accuracy. The sensors' performance reached correlations over r=0.9r=0.9r=0.9 in most of the cases. Lower correlations and significant measurement errors depend specifically on the selected sensor.
Nova Scientia, 2020
Introduction : The electrical impedance measurement and characterization of biological tissues al... more Introduction : The electrical impedance measurement and characterization of biological tissues allow to distinguish between a healthy and pathological tissues. The use of techniques such as electrical impedance tomography is widely used in clinical testing through various applications. In this work the Linear Back Projection (LBP) method is employed to reconstruct images from electrical impedance measurements in order to obtain the location of carcinoma emulator previously inserted within female-breast-shaped agar-agar models. Method : A ring arrangement of eight electrodes was used for measuring the impedance on the seven female-breast-shaped agar-agar models. A cross section of a healthy female breast (without emulators) corresponding to the measurement plane of the ring electrode arrangement was designed and simulated in the COMSOL software. The sensitivity maps of each pair of electrodes along the impedance measurement were computed using the conductivity distribution data obtai...
2020 IEEE International Autumn Meeting on Power, Electronics and Computing (ROPEC), 2020
Titanium dioxide (chemical formula TiO2) is a semiconductor that absorbs electromagnetic radiatio... more Titanium dioxide (chemical formula TiO2) is a semiconductor that absorbs electromagnetic radiation in the UV region; according to the type of crystallization, different crystalline distributions will be formed (anatase, rutile and brookite) which have significant differences in their chemical, mechanical and electrical properties; the last mentioned property is currently a little-known field of research, however TiO2 is the most widely used photocatalyst and it is currently used to degrade various types of pollutants in the medium. In this paper, a methodology is designed and implemented to know the electrical behavior of anatase, rutile and brookite crystalline structures; the study is developed from the simulation in Comsol Multiphysic software; measurements of electrical properties are made with the technique of electrical impedance spectroscopy in a measurement frequency range of 4Hz to 8MHz. During the process, the particular geometric constants for this investigation are obtai...
Sensors, 2021
Quantifying the quality of upper limb movements is fundamental to the therapeutic process of pati... more Quantifying the quality of upper limb movements is fundamental to the therapeutic process of patients with cerebral palsy (CP). Several clinical methods are currently available to assess the upper limb range of motion (ROM) in children with CP. This paper focuses on identifying and describing available techniques for the quantitative assessment of the upper limb active range of motion (AROM) and kinematics in children with CP. Following the screening and exclusion of articles that did not meet the selection criteria, we analyzed 14 studies involving objective upper extremity assessments of the AROM and kinematics using optoelectronic devices, wearable sensors, and low-cost Kinect sensors in children with CP aged 4–18 years. An increase in the motor function of the upper extremity and an improvement in most of the daily tasks reviewed were reported. In the population of this study, the potential of wearable sensors and the Kinect sensor natural user interface as complementary devices...
El presente articulo describe el diseno, desarrollo y resultados obtenidos de un sistema propuest... more El presente articulo describe el diseno, desarrollo y resultados obtenidos de un sistema propuesto de medicion de bioimpedancia electrica. Para ello el articulo incluye una revision de las propiedades electricas de los tejidos biologicos, asi como la definicion de bioimpedancia electrica. El sistema esta basado tanto en un acondicionamiento de las senales asi como en un procesamiento digital llevado a cabo mediante un procesador digital de senales, el calculo del valor de la impedancia compleja se realiza mediante un algoritmo propuesto. Con rango de frecuencias en la medicion de la bioimpedancia de 500Hz hasta 10KHz, suficiente para caracterizar el comportamiento electrico de algunos tejidos biologicos incluido la piel humana. De acuerdo a los resultados obtenidos el prototipo resultante representa una solucion economicamente viable y completamente funcionalen aplicaciones portatiles.
Resumen En este articulo se presenta una metodologia eficaz y de bajo costo para determinar la pr... more Resumen En este articulo se presenta una metodologia eficaz y de bajo costo para determinar la presion intraocular (PIO) a partir de la medicion de impedancia electrica compleja en un rango de frecuencias especifico. El aumento en la PIO generado por el exceso de fluido en el cuerpo vitreo, dana el nervio optico, este aumento es propiciado por el glaucoma. La propuesta de este trabajo es relacionar la medicion de la impedancia electrica compleja con la PIO. La variacion de la PIO se logra inyectando una solucion oftalmica al globo ocular. En la experimentacion se utilizo tejido ex vivo de muestras porcinas y a su vez un tonometro para medir directamente la PIO. Los cambios de presion en el ojo modifican la magnitud de la impedancia electrica compleja que es registrada para analizar la relacion con la PIO. Tambien se discute la ubicacion y geometria de los electrodos de medicion. Palabra(s) Clave: Bioimpedancia, Espectroiscopia, Glaucoma. Abstract This article presents an effective a...
En este trabajo se presenta de forma breve la simulacion realizada (en un software especializado ... more En este trabajo se presenta de forma breve la simulacion realizada (en un software especializado de simulacion multifisica llamado COMSOL), con una metodologia que tiene la finalidad de ubicar tejido patologico dentro de una mama femenina. El objetivo es obtener un parametro visual con el cual se puedan comparar los resultados numericos obtenidos por el analisis de bioimpedancia y por consiguiente indicar el area donde posiblemente se encuentre un carcinoma. Para ello se utilizo un arreglo de 12 electrodos, siendo uno de ellos el electrodo pivote, al cual se le aplicara un voltaje a cierta frecuencia y mediante un barrido se obtiene la corriente para un par de electrodos con la cual se determinara la impedancia correspondiente
Journal of Real-Time Image Processing, 2020
Convolutional Neural Networks (CNN) have become one of the best algorithms in machine learning fo... more Convolutional Neural Networks (CNN) have become one of the best algorithms in machine learning for content classification of digital images. The CNN computational complexity is much larger than traditional algorithms, that is why the use of Graphical Processor Units (GPU) and online servers to achieve operations acceleration is a common solution. However, there is a growing demand for real-time processing solutions in the object recognition field mainly implemented on embedded systems, which are limited both in resources and energy consumption. Recently, reported works are focused on minimizing the required resources through two design strategies. The first one is by implementing one accelerator that can be adapted to the operations of the whole CNN. The CNN architecture proposals with one accelerator for each convolution layer belong to the second design strategy, where higher performance is achieved in multiple image processing. A new design strategy is proposed in this paper, which is based on multiple accelerators using a layer operation chaining scheme for computing in parallel the operations corresponding to multiple CNN layers. Three types of parallel data processing are adopted in the proposed architecture, where the parallelism level for convolution layers is determined by defined cost-function-based algorithms. The proposed design strategy is shown by implementing three naive CNNs on a De2i-150 board, in which a peak acceleration of 18.04x was achieved in contrast with state-of-the-art design methods without layer operation chaining. Furthermore, the design results of one modified Alexnet CNN were obtained. According to the obtained results, the proposed design strategy allows to achieve a smaller processing time than that obtained by reported works using the other two design strategies. In addition, a competitive result in resources utilization is obtained for naive CNNs.
IEICE Electronics Express, 2019
Convolutional Neuronal Networks (CNN) implementation on embedded devices is restricted due to the... more Convolutional Neuronal Networks (CNN) implementation on embedded devices is restricted due to the number of layers of some CNN models. In this context, this paper describes a novel architecture based on Layer Operation Chaining (LOC) which uses fewer convolvers than convolution layers. A reutilization of hardware convolvers is promoted through kernel decomposition. Thus, an architectural design with reduced resources utilization is achieved, suitable to be implemented on low-end devices as a solution for portable classification applications. Experimental results show that the proposed design has a competitive processing time and overcomes resource utilization when compared with state-of-the-art related works.
Http Www Theses Fr, 2006
La conception et la realisation d'un microsysteme par spectroscopie de bioimpedance basee sur... more La conception et la realisation d'un microsysteme par spectroscopie de bioimpedance basee sur la technique du pont auto accorde dans la bande [100 Hz – 1MHz] a ete developpee. Le premier chapitre traite du contexte et des techniques de la mesure d'impedance de tissus biologiques (bioimpedance), ainsi que les parametres d'influence sur la mesure. Le second chapitre introduit la modelisation de la cellule de mesure avec des microelectrodes coplanaires en 2D et 3D, ainsi que l'analyse theorique permettant le calcul des proprietes dielectriques de tissus. On a utilise le logiciel Femlab pour effectuer la simulation. Le troisieme chapitre decrit la fabrication de la cellule de mesure par les techniques lithographiques, la problematique de l'interface – electrolyte et le circuit equivalent de l'impedance de polarisation. Celui-ci suggere une chaine de mesure pour la spectroscopie de bioimpedance. Le dernier chapitre de la these presentee validation experimentale de la chaine de mesure realisee, on a determinee la valeur de l'impedance complexe directement et indirectement et se retrouve les valeurs de la permittivite et conductivite. Les mesures sont effectuees sur une serum physiologique et du sang (animal et humaine), finalement tous les resultats experimentaux sont presentes et discutes.
Sensors, 2014
Nitrogen plays a key role in crop yields. Hence, farmers may apply excessive N fertilizers to cro... more Nitrogen plays a key role in crop yields. Hence, farmers may apply excessive N fertilizers to crop fields, inducing environmental pollution. Crop N monitoring methods have been developed to improve N fertilizer management, most of them based on leaf or canopy optical-property measurements. However, sensitivity to environmental interference remains an important drawback. Electrical impedance has been applied to determine the physiological and nutritional status of plant tissue, but no studies related to plant-N contents are reported. The objective of this article is to analyze how the electrical impedance response of plants is affected by their N status. Four sets of lettuce (Lactuca sativa L.) with a different N-source concentrations per set were used. Total nitrogen and electrical impedance spectra (in a 1 to 100 kHz frequency range) were measured five times per set, three times every other day. Minimum phase angles of impedance spectra were detected and analyzed, together with the frequency value in which they occurred, and their magnitude at that frequency. High and positive correlation was observed between plant N content and frequency values at minimum phase angle with no significant variations
Biosystems Engineering: Biofactories for Food Production in the Century XXI, 2014
ABSTRACT Nowadays, there exist several threats around the world that cause catastrophic damages t... more ABSTRACT Nowadays, there exist several threats around the world that cause catastrophic damages to the planet. One of the most important menaces is the lack of food that affects the health of people around the world. Animals and plants need food to survive, the survival insurance of both will help to ensure the food production and by consequence the aliment for each person around the world, which is a priority issue in all countries. At the present time, the food production has been affected more drastically by several biotic and abiotic factors that day by day diminish the quantity and quality of the worldwide food; this menaces the food security, principally in less developed countries.