76 results on '"MODELO COMPUTACIONAL"'
Search Results
2. Modelo computacional para reconocimiento de lenguaje de señas en un contexto colombiano.
- Author
-
Ortiz-Farfán, Nelson and Camargo-Mendoza, Jorge E.
- Published
- 2020
- Full Text
- View/download PDF
3. Aplicación multiplataforma de modelo computacional predictivo
- Author
-
Morales Carrillo, Jéssica Johanna, Cedeño Valarezo, Luis Cristóbal, Pinargote Bravo, Victor Joel, Cajape Bravo , Jesús Stefano, and Ormaza Calderón, Jonathan Geovanny
- Subjects
flask ,Computational model ,model as a service ,modelo API ,Modelo Computacional ,API model ,modelo como servicio - Abstract
The objective of this research was to carry out an application that allows the integration of a computational model to a multiplatform application, for which data was taken, the information from a supervised learning classification model regarding the collection of information on student dropout in the context of of the covid-19, this research was developed at the Escuela Superior Politécnica Agropecuaria de Manabí Manuel Félix López. The methodology that was proposed for the respective development was Extreme programming (XP). Starting from a trained model, for which the python-based flask framework was used, then we proceeded to create a service to consume the model, later the respective tests were carried out using postman as a web client. The main result of the research was that the Flask Framework allowed the development and implementation of a RES API in a much more agile and easy way for the consumption of data from the predictive model., El objetivo de esta investigación fue realizar una aplicación que permita la integración de un modelo computacional a una aplicación multiplataforma, para ello se tuvo como datos, la información de un modelo de clasificación de aprendizaje supervisado respecto al levantamiento de información sobre la deserción estudiantil en el contexto del covid-19, esta investigación fue desarrollada en la Escuela Superior Politécnica Agropecuaria de Manabí Manuel Félix López. La metodología que se planteó para el respectivo desarrollo fue Extreme programing (XP). Partiendo de un modelo entrenado, para lo cual se utilizó el framework flask basado en python, luego se procedió a crear un servicio para consumir el modelo, posteriormente se realizaron las respectivas pruebas utilizando postman como cliente web. Se obtuvo como principal resultado dentro de la investigación, que el Framework Flask permitió desarrollar e implementar un API RES de forma mucho más ágil y fácil para el consumo de datos del modelo predictivo.
- Published
- 2023
- Full Text
- View/download PDF
4. Seismic performance analysis and assessment of a precast bridge computational model.
- Author
-
Benjumea, José, Saiidi, M. “Saiid”, and Itani, Ahmad
- Subjects
- *
EARTHQUAKE resistant design , *BRIDGES , *BRIDGE bearings , *EARTHQUAKE engineering , *SEISMIC response , *SHAKING table tests , *ENGINEERING laboratories , *PERFORMANCE evaluation - Abstract
A large-scale, two-span bridge model constructed by assembling precast elements was tested under a series of bi-axial ground motions simulated on a shake table at the Earthquake Engineering Laboratory at the University of Nevada, Reno. The response of the bridge was estimated before the tests using a three-dimensional computational model developed in OpenSees software. After the tests, key measured seismic responses were compared to those predicted by the computational model to assess the modeling assumptions. Relatively large errors for the displacements, base shears, and hysteretic response of the bridge were observed. The influence of the earthquake loading, materials, connectivity of the precast elements, and boundary conditions in the computational model on the errors are discussed in this paper. Future modeling directions are proposed to reduce these errors. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
5. The effect of frequency in the electrical stimulation of chondrocytes.
- Author
-
Vaca-González, Juan Jairo, Escobar-Huertas, Juan Felipe, and Garzón-Alvarado, Diego Alexander
- Subjects
CARTILAGE cells ,BIOMIMETIC materials ,ELECTRIC fields ,CARTILAGE - Abstract
Copyright of Visión Electrónica is the property of Fondo de Universidad Distrital Francisco Jose de Caldas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
- Full Text
- View/download PDF
6. Modelado computacional del comportamiento electrofisiológico de neuronas en entorno de programación 'Neuron'
- Author
-
Baima Samper, Tomás
- Subjects
Potencial de acción ,Spinal cord ,Computational model ,Modelo computacional ,Action potential ,Neuron ,Médula espinal ,Canales iónicos ,TECNOLOGIA ELECTRONICA ,Bioelectricidad ,Neurona ,Bioelectricity ,Grado en Ingeniería Biomédica-Grau en Enginyeria Biomèdica ,Ion channels ,Entorno "Neuron" ,"Neuron" environment - Abstract
[ES] Los modelos computacionales se han utilizado desde hace décadas para simular el comportamiento electrofisiológico de células excitables tales como las neuronas. Aunque generalmente se emplean lenguajes o entornos de programación tales como el Matlab o el C, el uso del entorno "Neuron" permite realizar simulaciones de redes de neuronas de una manera más eficiente. En este trabajo, se desarrollará un software en este entorno de programación para simular las conexiones sinápticas entre neuronas pertenecientes a la médula espinal dañadas y neuronas implantadas con el fin de reconectar las partes dañadas de la médula., [EN] Computational models have been used for decades to simulate the electrophysiological behavior of excitable cells such as neurons. Although programming languages such as Matlab or C are generally used, the use of the "Neuron" environment allows simulations of neural networks to be carried out more efficiently. In this work, software will be developed in this programming environment to simulate the synaptic connections between neurons belonging to the spinal cord wholly or partially severed and neurons implanted in order to reconnect the damaged parts of the cord.
- Published
- 2022
7. Modelado computacional del efecto de bombas, intercambiadores y cotransportadores iónicos en el potencial de acción neuronal
- Author
-
Valiente Vizcaíno, Pablo
- Subjects
Potencial de acción ,Cotransportadores iónicos ,Bombas iónicas ,Computational model ,Modelo computacional ,Ion pumps ,Action potential ,Neuron ,TECNOLOGIA ELECTRONICA ,Bioelectricidad ,Neurona ,Bioelectricity ,Ionic cotransporters ,Grado en Ingeniería Biomédica-Grau en Enginyeria Biomèdica ,Homeostasis ,Intercambiadores iónicos ,Ion exchangers - Abstract
[ES] En los modelos matemáticos comúnmente utilizados para simular el comportamiento eléctrico de las neuronas, raras veces se incluyen las bombas iónicas (como la bomba sodio-potasio), intercambiadores iónicos (como el intercambiador sodio-calcio) y los cotransportadores iónicos (por ejemplo, el cotransportador cloro-potasio) en las ecuaciones de las corrientes eléctricas transmembrana. En este trabajo se ha desarrollado un software de simulación en entorno Matlab que incluya estas corrientes en un modelo de una neurona y se ha estudiado su efecto en las variaciones dinámicas en las concentraciones de los electrolitos. Para llegar a este software se han fusionado dos modelos diferentes realizando distintos estudios de sensibilidad. Finalmente se han obtenido dos posibles modelos uno con buena dinámica y otro con correcta magnitud de las corrientes. Se ha alcanzado en ambos casos un buen ajuste de la bomba de calcio y del transportador sodio-calcio. En el caso del cotransportador de cloro-potasio, la bomba sodio-potasio y el cotransportador cloro-potasio-sodio, se requerirían datos experimentales para poder mejorar el ajuste., [EN] In the mathematical models commonly used to simulate the electrical behavior of neurons, ion pumps (such as the sodium-potassium pump), ion exchangers (such as the sodium-calcium exchanger), and ion cotransporters (such as the potassium-chloride cotransporter) are rarely included in the equations of the transmembrane electrical currents. This work aims to develop a simulation software package in Matlab that includes these currents in a model of a neuron and to study their effect on dynamic variations in electrolyte concentrations. In this work, a simulation software has been developed in Matlab which includes these currents in a model of a neuron, and also their effect on dynamic variations in electrolyte concentrations has been studied. This software is the result of merge two different models carrying out different sensitivity studies. Finally, two models have been obtained, one with good dynamics and the other with the correct magnitude of the currents. A good fit of the calcium pump and the sodium-calcium transporter has been achieved in both cases. In the case of the chlor-potassium cotransporter, the sodium-potassium pump, and the chlor-potassium-sodium cotransporter, experimental data is required to improve the fit., [CAT] Als models matemàtics comunament utilitzats per a simular el comportament elèctric de les neurones, poques vegades s'inclouen les bombes iòniques (com la bomba sodi-potassi), intercanviadors iònics (com l'intercanviador sodi-calci) i els cotransportadors iònics (per exemple, el cotransportador clor-potassi) a les equacions de les corrents elèctriques transmembrana. A aquest treball s'ha desenvolupat un software de simulació en un entorn Matlab que inclogui aquestes corrents en un model d'una neurona i s'ha estudiat el seu efecte a les variacions dinàmiques a les concentracions dels electròlits. Per arribar a aquest software s'han fusionat dos models diferents realitzant diferents estudis de sensibilitat. Finalment s'han obtingut dos possibles models, un amb bona dinàmica i un altre amb correcta magnitud de les corrents. S'ha arribat a ambdós dos casos a un fructífer ajustament de la bomba de calci i del transportador sodi-calci. En el cas del cotransportador de cloro-potassi, la bomba sodi-potassi i el cotransportador clor-potassi-sodi encara està per afinar, es requereixen dades experimentals per a poder millorar l'ajustament.
- Published
- 2022
8. Estudio de la eficacia antiarrítmica de fármacos en isquemia aguda de miocardio mediante simulación computacional
- Author
-
Loidi Yarza, Ander
- Subjects
Acute myocardial ischemia ,Computational model ,Modelo computacional ,Eficacia antiarrítmica ,Isquemia aguda de miocardio ,TECNOLOGIA ELECTRONICA ,Bioelectricidad ,Bioelectricity ,Máster Universitario en Ingeniería Biomédica-Màster Universitari en Enginyeria Biomèdica ,Screening ,Antiarrhythmic efficacy ,Hyperkalemia ,Drug ,Fármaco ,Hiperkalemia - Abstract
[ES] Los modelos computacionales basados en descripciones matemáticas con mucho detalle biofísico y electrofisiológico son una herramienta cada vez más utilizad para estudiar la seguridad y eficacia de fármacos y, en particular, de sus efectos en el funcionamiento del corazón. Además, la isquemia miocárdica aguda es una situación patológica del corazón en el que, tras la oclusión de una arteria coronaria, el riesgo de sufrir arritmias potencialmente mortales es elevado. En este trabajo, se utilizará la simulación computacional para estudiar la eficacia de un grupo muy numeroso de fármacos en la prevención de arritmias ventriculares en esta situación patológica. ara ello, se programarán modelos electrofisiológicamente muy detallados que permitirán establecer el efecto de dichos fármacos sobre la evolución de la concentración extracelular de potasio, uno de los biomarcadores de riesgo arrítmico más importantes., [EN] Computational models based on mathematical descriptions with a high degree of biophysical and electrophysiological detail are an increasingly used tool to study the safety and efficacy of drugs and, in particular, their effects on heart function. In addition, acute myocardial ischemia is a pathological condition of the heart in which, after the occlusion of a coronary artery, the risk of life-threatening arrhythmias is high. In this work, computer simulation will be used to study the efficacy of a very large group of drugs in the prevention of ventricular arrhythmias in this pathological situation. For this purpose, very detailed electrophysiological models will be programmed that will allow establishing the effect of these drugs on the evolution of extracellular potassium concentration, one of the most important biomarkers of arrhythmic risk.
- Published
- 2022
9. PRÓTESE DE JOELHO SOB CARGA ASSIMÉTRICA.
- Author
-
FERNANDES, INÊS S. and FONSECA, ELZA M. M.
- Abstract
Copyright of Revista Iberoamericana de Ingeniería Mecánica is the property of Editorial UNED and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2017
- Full Text
- View/download PDF
10. Modelo computacional para reconocimiento de lenguaje de señas en un contexto colombiano
- Author
-
Jorge E. Camargo-Mendoza and Nelson Ortiz-Farfán
- Subjects
modelo computacional ,Computer science ,Video camera ,02 engineering and technology ,Sign language ,computer.software_genre ,lcsh:Technology ,Task (project management) ,law.invention ,Machine Learning ,lenguaje de señas ,Software ,law ,Factor (programming language) ,0202 electrical engineering, electronic engineering, information engineering ,sign language ,computer.programming_language ,Training set ,lcsh:T ,business.industry ,personas sordas ,020207 software engineering ,Public repository ,computational model ,Aprendizaje de Maquina ,lcsh:TA1-2040 ,aprendizaje de maquina ,020201 artificial intelligence & image processing ,Artificial intelligence ,Personas sordas ,lcsh:Engineering (General). Civil engineering (General) ,business ,computer ,Deaf people ,Natural language processing ,Meaning (linguistics) - Abstract
Resumen Este documento presenta la implementación de un software de reconocimiento de lenguaje de señas colombiano para personas sordas. Para este propósito, el Aprendizaje de Máquina será usado como base del sistema específico. Hoy en día no existe un repositorio público de imágenes o video que contenga estas señas ni la información necesaria para alcanzar esta meta, siendo uno de los principales impedimentos para iniciar la tarea. Por esta razón, se comenzó con la construcción de un repositorio. Pese a las dificultades de tiempo de los participantes, cinco personas realizaron las señas ante una cámara de video, de donde se obtuvieron las imágenes que compondrían el repositorio. Una vez hecho esto, las imágenes se usaron como datos de entrenamiento de un modelo computacional óptimo que puede predecir el significado de una nueva imagen presentada. Evaluamos el rendimiento del método utilizando medidas de clasificación y comparando diferentes modelos. La medición conocida como Accuracy fue un factor importante para medir los diferentes modelos obtenidos y así elegir el más adecuado. Los resultados muestran que es posible proporcionar nuevas herramientas a las personas sordas para mejorar la comunicación con otras personas que no conocen el lenguaje de señas. Una vez que se han elegido los mejores modelos, se prueban con nuevas imágenes, similares a las del entrenamiento, donde se puede ver que el mejor modelo logra una tasa de éxito de alrededor del 68 % de las 22 clases utilizadas en el sistema. Abstract This document presents the implementation of a Colombian sign language recognition software for deaf people. For this purpose, Machine Learning will be used as the basis of the specific system. Today there is no public repository of images or video that contains these signs or the information necessary to achieve this goal, being one of the main obstacles to undertake the task. For this reason, the construction of a repository was started. Despite the time constraints of the participants, five people carried out the signs in front of a video camera, from which the images that would make up the repository were obtained. Once this was done, the images were used as training data for an optimal computer model that can predict the meaning of a new image presented. We evaluated the performance of the method using classification measures and comparing different models. The measurement known as Accuracy was an important factor in measuring the different models obtained and thus choosing the one most suitable. Results show that it is possible to provide new tools to deaf people to improve communication with others who do not know sign language. Once the best models have been chosen, they are tested with new images, similar to those in the training, where it can be seen that the best model achieves a success rate of around 68 % of the 22 classes used in the system.
- Published
- 2020
- Full Text
- View/download PDF
11. EXPERIMENTAL AND THEORETICAL STUDY OF ADIABATIC HUMIDIFICATION IN HVAC&R APPLICATIONS ESTUDIO TEÓRICO EXPERIMENTAL DE LA HUMIDIFICACION ADIABÁTICA EN APLICACIONES HVAC&R
- Author
-
Néstor Fonseca and Cristian Cuevas
- Subjects
Acondicionamiento de aire ,refrigeración ,auditoría energética ,modelo computacional ,Air conditioning ,refrigeration ,commissioning ,computational model ,Mechanical engineering and machinery ,TJ1-1570 ,Industrial engineering. Management engineering ,T55.4-60.8 - Abstract
This article presents the results of the study performed to obtain a theoretical unified treatment of adiabatic humidification to be applied in refrigeration and air conditioning systems that can be used as a calculate tool in field as a part of diagnosis in audit processes of this kind of systems. To achieve this, a series of tests and experimental analysis are performed on two types of systems. The computational model is able to predict the effectiveness of the system and the main variables at the system exhaust as temperature and humidity by using the measurement of temperature and mass flow rates that participle in the energy and mass and transfer. The key in the analysis is the global heat transfer coefficient AU, considering the influence of the water an air mass flow rates in the system. An example of each system considered in this study is shown, illustrating the validation of the model.Este artículo presenta los resultados del estudio realizado para obtener un tratamiento teórico unificado de la humidificación adiabática, aplicable a sistemas de refrigeración y acondicionamiento de aire con la cual generar una herramienta de cálculo que pueda ser utilizada en terreno como parte de su diagnóstico en auditorías energéticas de este tipo de sistemas. Para lograr esto se realizan una serie de ensayos y análisis de tipo experimental en dos diferentes clases de equipo. El modelo computacional permite predecir la efectividad del sistema y principales variables de salida como la temperatura y contenido de humedad mediante la medición de las condiciones de entrada de temperatura y flujos másicos de los fluidos que intervienen en la transferencia de masa y energía. La clave en el análisis es la definición del coeficiente global de transferencia de calor AU, considerando la influencia de los flujos de agua y aire en el sistema. Se describe un ejemplo de validación del modelo por cada tipo de sistema seleccionado en este estudio.
- Published
- 2010
12. A spatial computational hybrid model to understand the level of migration across metropolitan areas in Mexico.
- Author
-
Fuentes, Estela Rivero and López, Marcos Valdivia
- Subjects
INTERNAL migration ,METROPOLITAN areas ,SPATIAL analysis (Statistics) - Abstract
Copyright of Carta Económica Regional is the property of Universidad de Guadalajara and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2017
- Full Text
- View/download PDF
13. Programa computacional para geração de séries sintéticas de precipitação Software for generation of synthetic series of precipitation
- Author
-
Sidney S. Zanetti, Fernando F. Pruski, Michel C. Moreira, Gilberto C. Sediyama, and Demetrius D. Silva
- Subjects
chuva ,gerador climático ,modelo computacional ,rainfall ,climatic generator ,computational model ,Agriculture (General) ,S1-972 - Abstract
Desenvolveu-se um programa computacional que permite a aplicação da metodologia para geração de séries sintéticas de precipitação desenvolvida por OLIVEIRA (2003). O desenvolvimento do aplicativo foi viabilizado pela elaboração de um algoritmo computacional em ambiente de programação "Borland Delphi 6.0". Os dados de entrada necessários são provenientes de banco de dados no formato padronizado pela Agência Nacional de Águas (ANA) com registros pluviométricos diários provenientes de estações meteorológicas. A partir dessas informações, o programa computacional é capaz de gerar séries sintéticas de precipitação diária contendo o total precipitado em milímetros, a duração do evento em horas, o tempo padronizado de ocorrência da intensidade máxima instantânea e a intensidade máxima instantânea padronizada. A série sintética gerada é armazenada em arquivos no formato "Texto" que podem ser acessados posteriormente por outros aplicativos e/ou planilhas eletrônicas. Além dos arquivos, são apresentadas várias informações na forma de gráficos e quadros, facilitando a avaliação do desempenho da metodologia desenvolvida.A computational model was developed to generate synthetic series of rainfall using the method developed by OLIVEIRA (2003). The software was developed in Borland Delphi 6.0 environment. The input data come from the daily precipitation data in the standardized format of the National Water Agency (ANA). The software is capable to generate synthetic series of daily rainfall containing the amount and the duration of the rainfall, and the standardized event time of the maximum instantaneous intensity. The generated synthetic series are stored in text-formatted files that may be accessed by others softwares and/or electronic datasheets. There were also presented graphs and tables format, to easily evaluate the performance of the method developed.
- Published
- 2005
- Full Text
- View/download PDF
14. Evaluación biomecánica de daño en hueso trabecular primario de la epífisis femoral en infantes de 6 años de edad. Modelo computacional 3d usando elementos finitos
- Author
-
Pérez Castillo, Jonatan David, López Vaca, Oscar Rodrigo, and Universidad Santo Tomás
- Subjects
Hip ,Computational model ,Cadera ,Femoral epiphysis ,Osteonecrosis ,Modelo computacional ,Necrosis avascular ,Elementos finitos ,Epífisis femoral - Abstract
El estudio de enfermedad de Legg – Calvé – Perthes (LCPD) es de gran importancia ya que afecta en etapas de crecimiento donde los huesos y articulaciones están en constante cambio. Esta patología es causada por falta de irrigación sanguínea principalmente y debido a que es una enfermedad poco común es complicado realizar un diagnóstico acertado. Debido a que los tratamientos para este tipo de enfermedades requieren procedimientos quirúrgicos o invasivos en los pacientes y no siempre cumplen con su objetivo, el uso de herramientas computacionales se convierte en una alternativa viable para el análisis de estas patologías y entender su curso natural y la posible generación de métodos de contención, sin embargo, se han implementado diferentes modelos de carga bajo los cuales puede ser evaluado el comportamiento biomecánico del tejido óseo implicado, pero no hay un consenso sobre el tipo de modelo más adecuado para ser implementado en este tipo de estudios. A partir de tomografías computarizadas (TC) se reconstruyó el modelo CAD fisiológico y uno patológico de la cadera de un infante de 6 años, y a partir de simulación computacional se estudió el comportamiento de la cadera bajo condiciones sanas y necróticas teniendo en cuenta un modelo de carga vectorial y un modelo de carga muscular. Los resultados permiten evidenciar las ventajas y desventajas que se presentan al implementar un modelo de carga en específico frente a otro. Un modelo de carga vectorial permite representar de buena manera el comportamiento de la articulación coxofemoral mientras que el modelo de carga muscular brinda mejores aproximaciones en zonas específicas de la cadera. Sin embargo, el modelo muscular demanda un proceso más exhaustivo en la construcción de su modelo de carga el cual puede no ser necesario dependiendo del interés del estudio. The study of Legg - Calvé - Perthes disease (LCPD) is of great importance since it affects in stages of growth where bones and joints are constantly changing. This pathology is caused by lack of blood supply mainly and because it is a rare disease it is difficult to perform a correct diagnosis. Because the treatments for these types of needs require requirements surgical or invasive in patients and do not always meet their objective, the use of tools computational techniques becomes a viable alternative for the analysis of these pathologies and to understand their natural course and the possible generation of containment methods, however, different load models have been implemented under which the biomechanical behavior of the bone tissue involved can be evaluated, but there is no consensus on the most suitable type of model to be implemented in this type of study. From computed tomography (CT) scans, the physiological CAD model and a pathological one of the hip were reconstructed. of a 6-year-old infant, and from computer simulation the behavior of the hip was studied under healthy and necrotic conditions taking into account a vector load model and a muscle load model. The results show the advantages and disadvantages that arise when implementing a load model in specific versus another. A vector load model that allows a good representation of the behavior of the hip joint while the muscle loading model provides better approximations in areas specific to the hip. However, the muscle model demands a more exhaustive process in the construction of its load model which may not be necessary depending on the interest of the study. Ingeniero Mecánico http://unidadinvestigacion.usta.edu.co Pregrado
- Published
- 2021
15. Modelo computacional avançado para análise de estruturas de concreto armado e mistas em elevadas temperaturas
- Author
-
Natan Sian das Neves, Rodrigo Silveira Camargo, and Macksuel Soares de Azevedo
- Subjects
Materials science ,Discretization ,modelo computacional ,incêndio ,Thermal ,Polygon mesh ,Thermal analysis ,concrete-steel ,concreto-aço ,Building construction ,Plane (geometry) ,business.industry ,termo-estrutural ,General Medicine ,Structural engineering ,Finite element method ,Nonlinear system ,computational model ,thermo-structural ,finite elements ,elementos finitos ,Material properties ,business ,TH1-9745 ,fire - Abstract
This paper is concerned on the development of a computational model based on finite element procedures for advanced analysis capable of estimating the behavior of reinforced concrete and composite steel-concrete plane structures exposed to fire. The program implemented is called NASEN, the specific thermo-structural module is used to analyze structures under fire conditions. The effects of geometric nonlinearity, material nonlinearity and nonlinear thermal gradients are incorporated into the model, as well as the degradation of material properties with increased temperature. The methodology applied for the solution is based on the unidirectional coupling of the thermal and mechanical solutions. The cross-sections of the structural elements are discretized with two-dimensional meshes for thermal analysis, while the structural analysis uses a one-dimensional beam-column element. Numerical examples are presented to demonstrate the accuracy of the computational code developed in relation to the numerical and experimental solutions found in the literature. In summary, the program adequately predicted the response of the studied structures. resumo: O presente artigo tem como objetivo o desenvolvimento de um modelo computacional com base nos procedimentos do método dos elementos finitos. A análise avançada é capaz de estimar o comportamento de estruturas planas de concreto armado e, mistas de aço e concreto em situação de incêndio. O programa computacional implementado é denominado de NASEN e, utiliza um módulo termo-estrutural específico para análise de estruturas em condição de incêndio. Incorpora-se ao modelo os efeitos da não linearidade geométrica, não linearidade do material e gradientes térmicos não lineares, bem como a degradação das propriedades dos materiais com aumento da temperatura. A metodologia aplicada para solução tem como base o acoplamento unidirecional das soluções térmicas e mecânicas. As seções transversais dos elementos estruturais são discretizadas com malhas bidimensionais para análise térmica, enquanto a análise estrutural utiliza elemento unidimensional de viga-coluna. Exemplos numéricos são apresentados para demonstrar a precisão do código computacional desenvolvido em relação as soluções numéricas e experimentais encontradas na literatura. O programa computacional prevê adequadamente a resposta das estruturas estudadas.
- Published
- 2021
16. Artificial neural network model for simulation of water distribution in sprinkle irrigation.
- Author
-
de Menezes, Paulo L., de Azevedo, Carlos A. V., Eyng, Eduardo, Neto, José Dantas, and de Lima, Vera L. A.
- Subjects
SPRINKLER irrigation ,ARTIFICIAL neural networks ,WATER distribution ,COMPUTER simulation ,NOZZLES - Abstract
Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2015
- Full Text
- View/download PDF
17. A Markovian-based simulation model for the evolution of employees' emotional states during an organizational change
- Author
-
Oriol Lordan González, Vicenç Fernández Alarcón, Cristian Castillo Gutiérrez, Universitat Oberta de Catalunya (UOC), Universitat Politècnica de Catalunya, Universitat Politècnica de Catalunya. Departament d'Organització d'Empreses, and Universitat Politècnica de Catalunya. GRO - Grup de Recerca en Organització
- Subjects
Organizational Behavior and Human Resource Management ,organizational change ,modelo computacional ,Strategy and Management ,Canvi organitzatiu -- Simulació per ordinador ,Markov process ,Economia i organització d'empreses::Direcció d'operacions [Àrees temàtiques de la UPC] ,simulación ,cambio organizativo ,canvi organitzatiu ,simulació ,model computacional ,Computer simulation ,simulation ,Simulación por ordenador ,Microeconomics ,symbols.namesake ,computational model ,Organizational change -- Computer simulation ,Organizational change ,Simulació per ordinador ,symbols ,Business and International Management ,Psychology - Abstract
This study aims to create a simulation model with which to analyse the spread of emotional states among the employees of an organization. The model takes into account the fact that workers are influenced by their co-workers and supervisors, and simultaneously analyses these interactions. The design of the simulation model follows a standard procedure: problem definition, data collection and configuration of model parameters, conceptual model, testing of the programmed model, and analysis of the results of the simulation. The resulting simulation model makes a novel contribution to the literature by providing social sciences researchers with a simple and efficient method of analysing the evolution and propagation of emotional states during an organizational change. This kind of approach is useful for research involving the simultaneous study of interaction between a number of employees
- Published
- 2021
18. Development of a software for the management of the sugarcane transport system (Saccharum spp.)
- Author
-
Santos, Neisvaldo Barbosa dos, Monteiro, Leonardo de Almeida, and Chioderoli, Carlos Alessandro
- Subjects
Truck and trailer ,Computational model ,Agricultural mechanization ,Planejamento e gerenciamento ,Modelo computacional ,Mechanical horse and semi-trailer ,Logistics ,Rodotrem ,Mecanização agrícola ,Tire retreads ,Logística ,Simulação ,Recapagens de pneus ,Planning and management ,Treminhão ,Simulation - Abstract
Brazil is the world's largest producer of sugarcane destined for sugar, alcohol and cogeneration plants. Sugar cane transportation from the plants is carried out by trucks with trailers and mechanical horses with semi-trailers. The modal road system for the transportation of cane makes use of this equipment, in order to meet the continuous demand for the raw material harvested, correct at a minimum cost. The objective of this work is to analyze the variables of the operational and economic performance of different sugarcane transport equipment. Finding a difficulty in meeting the objective in the field conditions, it was decided to develop a computational model called “TransporteCana”, in an electronic spreadsheet. The model was checked for possible routine errors, validated, used in the analysis of variables and in the generation of results. The results showed that an increase in the average distance radius negatively impacts the operational and economic performance of the groups. The bodywork load, average distance radius and fuel price are the variables that most impact the cost of transport system equipment. The set of bitruck trucks and trailers has a higher operational cost of production and a greater impact on the cost of the plant's transportation system. O Brasil é o maior produtor mundial de cana-de-açúcar destinada às usinas produtoras de açúcar, álcool e co-geração de energia elétrica. O transporte de cana das usinas é realizado por caminhões com reboques e cavalos mecânicos com semireboques. O sistema modal rodoviário do transporte de cana faz uso desses equipamentos, a fim de atender a demanda contínua da matéria-prima colhida, visando alcançar um mínimo custo. O objetivo deste trabalho é de analisar as variáveis do desempenho operacional e econômico de diferentes equipamentos do transporte de cana-de-açúcar. Devido a dificuldade em atender o objetivo nas condições a campo, optou-se em desenvolver um modelo computacional denominado “TransporteCana”, em planilha eletrônica. O modelo foi verificado quanto a possíveis erros de rotina, validado, utilizado na análise das variáveis e na geração de resultados. Os resultados evidenciaram que aumento do raio médio da distância impacta negativamente no desempenho operacional e econômico dos conjuntos. A carga das carrocerias, raio médio da distância e preço do combustível são as variáveis que mais impactam no custo dos equipamentos do sistema de transporte. O conjunto caminhão bitruck e reboque tem maior custo operacional de produção e maior impacto no custo do sistema de transporte da usina.
- Published
- 2021
19. Estudio comparativo del efecto farmacológico en poblaciones de células ventriculares sanas y patológicas mediante modelado y simulación
- Author
-
Scals Carmona, Sara de
- Subjects
Potencial de acción ,Population of models ,Computational model ,Cardiomiocito ,Insuficiencia cardíaca ,Modelo computacional ,Action potential ,Heart failure ,Cardiomyocyte ,TECNOLOGIA ELECTRONICA ,Transitorio de calcio ,CiPA ,Grado en Ingeniería Biomédica-Grau en Enginyeria Biomèdica ,Torsade de Pointes ,Calcium transient ,Población de modelos ,Drug ,Fármaco - Abstract
[ES] La Torsade de Pointes es una taquiarritmia ventricular responsable de la retirada de ciertos fármacos del mercado por ser uno de los efectos adversos más graves. Para reducir su incidencia, han surgido iniciativas como CiPA, que evalúa la predicción del riesgo proarrítmico de fármacos; incluyendo modelos in silico. En el presente trabajo se analiza el impacto de diversos fármacos sobre los cardiomiocitos ventriculares sanos y con insuficiencia cardíaca mediante la simulación y modelado computacional de los comportamientos electrofisiológicos de las células cardíacas utilizando los modelos computacionales de O¿Hara et. al (2011), Tomek et al. (2019), y un modelo de O¿Hara modificado (ORdmJ). 28 fármacos de CiPA, clasificados en función de su riesgo torsadogénico, fueron simulados con el bloqueo de poro simple mediante la ecuación de Hill. Se emplearon modelos celulares con insuficiencia cardíaca y se realizó un análisis de sensibilidad que estudiaba la contribución de las corrientes en el potencial de acción y el transitorio de calcio. Asimismo, se consideró la variabilidad electrofisiológica producida en sujetos de una misma especie simulando poblaciones de modelos de cardiomiocitos humanos. Los resultados muestran que las corrientes INaL e INaCa son grandes contribuyentes en el alargamiento del potencial de acción y que JSERCA es una de las mayores responsables de la disminución de calcio en células con insuficiencia cardíaca en el modelo de Tomek et al. Adicionalmente, el estudio mostró que es importante emplear modelos realistas del comportamiento electrofisiológico ventricular, que incluya variabilidad poblacional, puesto que los efectos farmacológicos pueden variar ligeramente con el individuo. Además, se obtienen respuestas agravadas en situaciones patológicas, lo cual destaca la importancia de considerar estas situaciones en la evaluación de seguridad cardíaca. En conclusión, esta herramienta podría contribuir en las predicciones de efectos peligrosos en la producción de futuros medicamentos ajustándose a las distintas condiciones electrofisiológicas y/o patológicas., [EN] Torsade de Pointes is a ventricular tachyarrhythmia responsible for the withdrawal of certain drugs from the market as one of the most dangerous side effects. In order to reduce its incidence, initiatives such as CiPA, which evaluates the probability of proarrhythmic risk of drugs, including the use of in silico models, have emerged. At present, we analyze the impact of various drugs on healthy and failing ventricular cardiomyocytes by simulating and computationally modeling the electrophysiological behavior of cardiac cells using the computational models of O'Hara et. al (2011), Tomek et al. (2019), and a modified O'Hara model (ORdmJ). 28 CiPA drugs, ranked according to their torsadogenic risk, were simulated with single pore blockade using the Hill equation. Cellular models with heart failure were used and a sensitivity analysis studying the contribution of currents to the action potential and calcium transient was performed. The electrophysiological variability present in subjects of the same species was also considered by simulating populations of models of human cardiomyocytes. The results show that INaL and INaCa currents are major contributors to action potential elongation and that JSERCA is a major contributor to calcium depletion in cells of those subjects with heart failure in the model of Tomek et al. In addition, the study showed that it is important to employ realistic models of ventricular electrophysiological behavior, including population variability, since pharmacological effects may vary slightly with the individual. In addition, aggravated responses are obtained in pathological situations, which highlights the importance of considering these situations in cardiac safety assessment. In conclusion, this tool could contribute to the prediction of hazardous effects in the production of future drugs by adjusting for different electrophysiological and/or pathological conditions., [CA] La Torsade de Pointes és una taquiarrítmia ventricular responsable de la retirada de certs fàrmacs del mercat per ser un dels efectes adversos més greus. Per resuir la seua incidència, han sorgit iniciatives com CiPA, que avalua la predicció del risc proarrítmic de fàrmacs; incloent models in silico. En el present treball s'analitza l'impacte de diversos fàrmacs sobre els cardiomiòcits ventriculars sans i amb insuficiència cardíaca mitjançant la simulació i modelatge computacional dels comportaments electrofisiològics de les cèl·lules cardíaques utilitzant els models computacionals d'O’Hara et. al (2011), Tomek et al. (2019), i un model d'O’Hara modificat (ORdmJ). 28 fàrmacs de CiPA, classificats en funció del seu risc torsadogènic, van ser simulats amb el bloqueig de porus simple mitjançant l'equació de Hill. Es van emprar models cel·lulars amb insuficiència cardíaca i es va realitzar una anàlisi de sensibilitat que estudiava la contribució dels corrents en el potencial d'acció i el transitori de calci. Així mateix, es va considerar la variabilitat electrofisiològica produïda en subjectes d'una mateixa espècie simulant poblacions de models de cardiomiòcits humans. Els resultats mostren que els corrents INaL i INaCa són grans contribuents en l'allargament del potencial d'acció i que JSERCA és un dels majors responsables de la disminució de calci en cèl·lules amb insuficiència cardíaca en el model de Tomek et al. Addicionalment, l'estudi va mostrar que és important emprar models realistes del comportament electrofisiològic ventricular, que incloga variabilitat poblacional, ja que els efectes farmacològics poden variar lleugerament amb l'individu. A més, s'obtenen respostes agreujades en situacions patològiques, la qual cosa destaca la importància de considerar aquestes situacions en l'avaluació de seguretat cardíaca. En conclusió, aquesta eina podria contribuir en les prediccions d'efectes perillosos en la producció de futurs medicaments ajustant-se a les diferents condicions electrofisiològiques i/o patològiques.
- Published
- 2021
20. Desarrollo de un modelo computacional para la evaluación mecánica y funcional de la articulación trapecio metacarpiana.
- Author
-
Ramirez, Fernando, Piscal, Carlos M., Guzmán, Andrés F., and Moreno, Constanza L.
- Subjects
- *
THUMB , *JOINTS (Anatomy) , *FINITE element method , *COMPUTER simulation , *PHYSIOLOGICAL stress , *TOMOGRAPHY , *ANATOMY - Abstract
A computational model for the thumb was developed in order to evaluate the stresses and strains in the Trapeziometacarpal joint under physiological conditions. A reconstruction of the 3D geometry of the thumb was performed through image processing of computerized axial tomographies. Based on anatomical and functional analysis of the thumb, a computational model was generated to simulate the behavior of the joint under normal working conditions. The tendon forces and the distribution of stresses in the joint were obtained by means of mechanics analysis using the finite element method; these analyses were performed for regular usage conditions and specific anatomical grip positions. [ABSTRACT FROM AUTHOR]
- Published
- 2014
21. Parametric analysis of drug distribution during infusions into the brain using an axisymmetric model with backflow.
- Author
-
Orozco, Gustavo A., Smith, Joshua H., and García, José J.
- Subjects
INTRAVENOUS therapy ,FINITE element method ,MASS transfer ,FLUID velocity measurements ,CATHETERS - Abstract
Copyright of Biomedical Engineering Journal / Revista Ingeniería Biomédica is the property of Biomedical Engineering Journal / Revista Ingenieria Biomedica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2014
22. Modelo computacional de un modulador Σ-Δ de 2° orden para la generación de señales de prueba en circuitos integrados analógicos.
- Author
-
Simancas, José G. and Ortiz, José C.
- Abstract
Copyright of Revista Inge@UAN. Tendencias de la Ingeniería is the property of Universidad Antonio Narino and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2014
23. Determinación de la estabilidad primaria del mini-implante de anclaje temporal (DAT) en diferentes densidades óseas del hueso maxilar
- Author
-
Rodríguez Lagos, Camilo Alejandro and López Vaca, Oscar Rodrigo
- Subjects
Strain plastic ,Computational model ,Removable appliances (Dentistry) ,Bone trabecular ,Dental morphology ,Morfología odontológica ,Orthodontics ,Modelo computacional ,Aparatos removibles (Odontología) ,Hueso trabecular ,Strain ,Ortodoncia ,Deformación plástica ,Esfuerzo ,Deformación ,Hueso cortical ,Strength ,Bone cortical - Abstract
Los mini-implantes (DAT) representan una eficaz alternativa en los últimos años en las intervenciones realizadas para aquellas personas que tiene insuficiencia estructural dental, aumentando la taza de éxito [9][10]. Su ventaja respecto a otros implantes es el proceso de recuperación y la fácil inserción sin afectación considerable en la zona ósea del hueso cortical y trabecular [2]. Por otro lado, durante el procedimiento se deben considerar algunas variables que afectan la estabilidad primaria del tratamiento; entre la cuales encontramos las propiedades mecánicas del tejido óseo el cual varia para cada paciente; la geometría del mini-implante, el ángulo y torque de inserción. La suma de estas variables determina el éxito del tratamiento. Por lo anterior, es de gran interés entender el comportamiento biomecánico del tejido óseo por la razón que este varía según la genética del paciente. Por lo tanto, el presenta trabajo se enfocará a estudiar y analizar la estabilidad primaria para diferentes densidades óseas del Hueso Maxilar. Mini-implants (DAT) represent an effective alternative in recent years in the interventions carried out for those people with structural dental insufficiency, increasing the rate of success [9] [10]. Its advantage over other implants is the recovery process and easy insertion without considerable involvement in the bony area of the cortical and trabecular bone [2]. On the other hand, some variables that affect the primary stability of the treatment must be considered during the procedure; Among which we find the mechanical properties of bone tissue which varies for each patient; the geometry of the mini-implant, the angle and insertion torque. The sum of these variables determines the success of the treatment. Therefore, it is of great interest to understand the biomechanical behavior of bone tissue for the reason that it varies according to the genetics of the patient. Therefore, the present work will focus on studying and analyzing the primary stability for different bone densities of the Maxillary Bone. Ingeniero Mecánico http://unidadinvestigacion.usta.edu.co Pregrado
- Published
- 2020
24. Estimación de la velocidad del agua en la Bahía Interior de Puno en el Lago Titicaca, mediante simulación numérica
- Author
-
Aguirre, César, Chicana, Julio, and Merma, Marco
- Subjects
Velocidad del agua ,computational model ,eutrophication ,Water speed ,temperatura ,modelo computacional ,temperature ,wind ,viento ,eutrofización - Abstract
The Inner Bay of Puno is located on Lake Titicaca in southern Peru, 2.6 m in average depth, 16.0 km in surface area. The mouth of the bay, populated by native reed beds, joins the Outer Bay through the north and south channels. The bay is an example of the negative impact of humans, where they discharge poorly treated wastewater, producing an increase in algal biomass, eutrophication and anoxia. The objective was to estimate the direction and magnitude of the speed of the water current, on an hourly scale controlled by relevant physical processes, between January 23 and 30, 2019. We collected meteorological data, depth and temperature of the water. We performed computational experiments using the ELCOM lake model. The rst scenario considered the closed bay, and as a result presented counterclockwise rotational ow in the north and clockwise in the south, with a speed that varied between 0.5 and 4.0 cm/s. The second scenario considered the entry and exit of water through the north and south channels, respectively, observing a ow from the north channel to the south channel, with a speed that varied between 20.0 and 50.0 cm/s., La Bahía Interior de Puno, está ubicada en el Lago Titicaca al sur del Perú, de 2.6 m de profundidad media, 16.0 km de área supercial. La boca de la bahía, poblado de cañaverales nativos, se une a la Bahía Exterior por los canales norte y sur. La bahía, es un ejemplo del impacto negativo del humano, donde descargan agua residual tratado decientemente, produciendo un incremento de biomasa algal, proceso de eutrozación y anoxia. El objetivo, fue estimar la dirección y magnitud de la velocidad de la corriente de agua, a escala horaria controlado por procesos físicos relevantes, entre el 23 y 30 de enero del 2019. Recogimos datos meteorológicos, profundidad y temperatura del agua. Realizamos experimentos computacionales usando el modelo para lagos ELCOM. El primer escenario consideró la bahía cerrada, y como resultado presentó ujo rotacional antihorario en el norte y horario en el sur, con rapidez que varió entre 0.5 y 4.0 cm/s. El segundo escenario, consideró ingreso y salida de agua por el canal norte y sur respectivamente, observándose un ujo del canal norte al canal sur, con rapidez que varió entre 20.0 y 50.0 cm/s
- Published
- 2020
25. Estudio mediante simulación del acoplamiento electromecánico en células ventriculares afectadas de insuficiencia cardíaca
- Author
-
Gutiérrez Santamaría, Sofía
- Subjects
Potencial de acción ,Acoplamiento electromecánico ,Fuerza activa ,Stretch activated ion channels ,Electromechanical coupling ,Computational model ,Cardiomiocito ,Insuficiencia cardíaca ,Modelo computacional ,Heart failure ,Action potential ,Cardiomyocyte ,Active force ,TECNOLOGIA ELECTRONICA ,Calcio ,Canales iónicos activados por estiramiento ,Grado en Ingeniería Biomédica-Grau en Enginyeria Biomèdica ,Calcium - Abstract
[ES] Las enfermedades cardiovasculares son la principal causa de defunción en todo el mundo según la OMS. La insuficiencia cardíaca es una de ellas y se caracteriza por la incapacidad del corazón para bombear la sangre suficiente a todo el cuerpo. Para el estudio de esta enfermedad se utiliza la simulación bioeléctrica computacional pues posibilita el estudio de cambios electrofisiológicos bajo determinadas condiciones. Este trabajo se centra en el acoplamiento electromecánico en células ventriculares a partir de los canales iónicos activados por estiramiento (SACs) y del calcio. Para ello, se utiliza el modelo electrofisiológico de potencial de acción (PA) de O¿Hara et al., en el que se incluye la formulación de las corrientes a través de los SACs de Pueyo et al., y el modelo mecánico de Land et al. Los resultados muestran el acortamiento del PA debido a la activación de los SACs, así como el aumento de la concentración intracelular de calcio ([Ca2+]i) en comparación con el modelo de O¿Hara et al. Asimismo, se evidencia que la fuerza activa es mayor con la incorporación de los SACs en células epicárdicas; en cambio, la fuerza pasiva es independiente del tejido cardíaco. En cuanto al análisis de sensibilidad del modelo de insuficiencia cardíaca para una célula epicárdica, se constata que al cambiar la conductancia de los SACs de activación instantánea de 0.01 a 0.006 nS/pF la fuerza activa disminuye; que cuanto menor es la [Ca2+]T50, mayor es la fuerza activa y menor la [Ca2+]i; y que la fuerza activa es mucho mayor con el remodelado de epicardio. Para todos estos resultados se han aportado nuevas hipótesis que deberían ser estudiadas en trabajos futuros., [EN] Cardiovascular diseases are the leading cause of death worldwide according to the WHO. Heart Failure is one of them and is characterized by the heart's inability to pump enough blood throughout the body. For the study of this disease, bioelectric computational simulation is used since it allows the study of electrophysiological changes under certain conditions. This work focuses on the electromechanical coupling in ventricular cells from stretch activated ion channels (SACs) and calcium. For this purpose, the O'Hara et al. electrophysiological model of the ventricular action potential (AP), in combination with the formulation of the currents through the SACs by Pueyo et al., and the Land et al. mechanical model are used. The results show the shortening of the AP due to the activation of the SACs, as well as the increase of the intracellular calcium concentration ([Ca2+]i) compared to O'Hara's et al. model. Likewise, it is shown that the active force is higher with the incorporation of the SACs into epicardial cells; in contrast, the passive force is independent of the cardiac tissue. As for the sensitivity analysis of the heart failure model for an epicardial cell, it was found that by changing the conductance of the instantaneously activating SACs from 0.01 to 0.006 nS/pF the active force decreases; that the lower the [Ca2+]T50, the higher the active force and the lower the [Ca2+]i; and that the active force is much higher with epicardial remodeling. For all these results, new hypotheses have been provided that should be studied in future work.
- Published
- 2020
26. Simulação do processo de produção de uma indústria de água mineral pelo método system dynamics
- Author
-
Silva, Giselle de Lima Paixão e, Geraldine, Robson Maia, Santana, Reginaldo Figueiredo, Bento, Juliana Aparecida Correia, Souza Neto, Menandes Alves de, and Caliari, Márcio
- Subjects
System ,lcsh:LC8-6691 ,Agua mineral ,lcsh:Special aspects of education ,modelo computacional ,Computational model ,indústria ,água mineral ,simulação ,sistema ,lcsh:Social Sciences ,lcsh:H ,Água Mineral ,Simulación ,lcsh:Science (General) ,Mineral water ,Simulation ,Industry ,lcsh:Q1-390 - Abstract
This research was conducted with the objective of implementing a computer model to simulate the steps that comprise the operational flowchart of a mineral water industry, using the software Stella 8.0. The model defined as dynamic, stochastic and discrete consisted of eleven interconnected blocks. It was built following the steps of characterizing the real system, creating the conceptual model, structuring and verification of computational model, data collection, and model validation. From data collected in the real system we obtained fits of the distributions used in assembling and verifying the model. Validation of the program was conducted by comparing the data of the real system with simulated data. The values collected in the real system were within the upper and lower limits on the graph obtained by regression analysis, with a confidence level of 95%, ensuring that the computer model adequately represents the real system. However, the computational model developed is appliable to simulate the dynamics of processing lines of Mineral Water, being a tool of production control, which allows the visualization of the behavior of the real system, facilitates the identification of errors, improve production flow, and reduces manufacturing costs by controlling the total processing time. Este trabajo se llevó a cabo con el objetivo de implementar un modelo computacional para simular los pasos de producción de una industria de agua mineral, utilizando el software Stella 8.0. El modelo definido como dinámico, estocástico y discreto constaba de once bloques interconectados, y se construyó siguiendo los pasos de caracterización del sistema real; creación del modelo conceptual; estructuración y verificación del modelo computacional; obtención de datos; y validación del modelo. A partir de los datos recopilados en el sistema real, se realizaron ajustes a las distribuciones utilizadas en el ensamblaje y verificación del modelo. La validación del programa se realizó comparando los datos del sistema real con los datos simulados. Los valores recopilados en el sistema real estaban dentro de los límites superior e inferior en el gráfico obtenido por el análisis de regresión, con un nivel de confianza del 95%, asegurando que el modelo computacional representaba adecuadamente el sistema real. Sin embargo, el modelo computacional desarrollado fue aplicable para simular la dinámica operativa de las líneas de procesamiento de Agua Mineral, ya que es una herramienta de control de producción, que permite visualizar el comportamiento del sistema real, facilita la identificación de errores, mejora el flujo productivo y reduce los costos industriales al controlar el tiempo total de procesamiento Este trabalho foi conduzido com o objetivo de implementar um modelo computacional para simular as etapas de produção de uma indústria de água mineral, através do software Stella 8.0. O modelo definido como dinâmico, estocástico e discreto constituiu-se de onze blocos interligados, e foi construído seguindo as etapas de caracterização do sistema real; criação do modelo conceitual; estruturação e verificação do modelo computacional; obtenção de dados; e validação do modelo. Partindo dos dados coletados no sistema real obteve-se os ajustes das distribuições utilizadas na montagem e verificação do modelo. A validação do programa foi efetuada através da comparação dos dados do sistema real com os dados simulados. Os valores coletados no sistema real apresentaram-se dentro dos limites superior e inferior no gráfico obtido pela análise de regressão, com nível de confiança de 95%, garantindo que o modelo computacional representasse de forma adequada o sistema real. Contudo, o modelo computacional desenvolvido foi aplicável para simular a dinâmica operacional de linhas processadoras de Água Mineral, por ser uma ferramenta de controle da produção, que permite a visualização do comportamento do sistema real, facilita a identificação de erros, melhora o fluxo produtivo e reduz custos industriais por controlar o tempo total de processamento.
- Published
- 2020
27. Caracterización de estrategias de control realimentado en control motor humano
- Author
-
Sánchez Pérez, Andrés
- Subjects
Simulaciones ,Computational model ,Simulations ,Human motor control ,Neurociencia ,Modelo computacional ,Control motor humano ,Average control ,INGENIERIA DE SISTEMAS Y AUTOMATICA ,Diseño de estrategias de control ,Grado en Ingeniería Biomédica-Grau en Enginyeria Biomèdica ,Control promedio ,Design of control strategies ,LQG ,Toma de decisiones ,Decision-making ,Neuroscience - Abstract
[ES] En teoría de control, ha sido propuesto que cuando los humanos se encuentran ante múltiples opciones (por ejemplo, hay varias frutas en una mesa y quieren coger una), hay una competición en el cerebro entre diferentes leyes de control, y los movimientos generados antes de una decisión final reflejan un "control promedio" donde los movimientos promedio son transitorios hasta que una de las estrategias se superpone, una vez se ha tomado esa decisión final. La hipótesis alternativa es que, en lugar de hacer un promedio entre diferentes planes motores (o controladores), el cerebro elige una opción intermedia y produce un controlador adecuado para esta opción. En este caso, se establece un objetivo o meta intermedio compensado y dependiente del tiempo, perseguido por el control, hasta que eventualmente corrige la trayectoria hacia una de las dos opciones. En este proyecto, se investigarán estas dos hipótesis en teoría para poder explorarlas y analizarlas desde un punto de vista computacional. Ambas estrategias se implementarán usando un entorno de control LQG de acuerdo con los modelos actuales de control en 'alcance' humano, y su actuación en comparación será puesta a prueba. Estas pruebas se realizarán en un modelo de brazo humano, ajustando los parámetros biomecánicos y explorando las características de ambos diseños. Hasta este punto, situaciones que involucran la toma de decisiones y perturbaciones mecánicas serán simuladas. La consistencia de los resultados simulados con un comportamiento humano durante el alcance será analizada. Los resultados del proyecto tendrán el potencial tanto para profundizar en un tema candente en neurociencia que se encuentra entre la toma de decisiones y la teoría de control, como para el diseño de estrategias de control adecuadas en dispositivos exoesqueléticos., [EN] It has been proposed that when humans face multiple options (for instance there are multiple fruits on a table and you want to reach for one), there is a competition in the brain between different control laws, and movements generated before final commitment reflect a motor averaging" where the averaged movements are transient ones until one of the strategies wins once a final decision is taken. The alternative hypothesis is that instead of averaging distinct motor plans (or controllers), the brain picks an intermediate option and produces one controller suitable for this option. In this case, a time-varying intermediate trade-off goal is set and control pursues it as it eventually drifts towards one of the options. In this project, we will investigate these two alternative hypotheses in theory in order to explore and challenge them from a computational standpoint. Both strategies will be implemented using the LQG control framework in agreement with current models of reaching control in humans, and their comparative performances will be tested. Testing will be carried out on a model of a human arm, by adjusting biomechanical parameters and exploring the features of both designs. To this end, situations involving decision-making and mechanical perturbations will be simulated. The consistence of the simulated results with actual human behavior during reaching will be assessed. The results of the project will have potential both to gain insight into a hot topic in neuroscience lying between decision-making and motor control, and in design of proper control strategies for exoskeleton devices.
- Published
- 2020
28. SIA: Modelo para simulação da irrigação por aspersão - Calibração e validação.
- Author
-
De Oliveira, Henrique F. E., Colombo, Alberto, Faria, Lessandro C., Beskow, Samuel, and do Prado, Giuliani
- Subjects
SPRINKLER irrigation ,UNIFORMITY of nature ,SIMULATION methods & models ,CALIBRATION ,MATHEMATICAL optimization ,SEQUENTIAL injection analysis ,MATHEMATICAL models - Abstract
Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2013
- Full Text
- View/download PDF
29. EXPERIMENTAL AND THEORETICAL STUDY OF ADIABATIC HUMIDIFICATION IN HVAC&R APPLICATIONS.
- Author
-
Fonseca, Néstor and Cuevas, Cristian
- Subjects
- *
HEAT transfer , *HUMIDITY control equipment , *ADIABATIC engines , *ENERGY auditing , *REFRIGERATION research , *AIR conditioning equipment , *COMPUTER simulation - Abstract
This article presents the results of the study performed to obtain a theoretical unified treatment of adiabatic humidification to be applied in refrigeration and air conditioning systems that can be used as a calculate tool infield as a part of diagnosis in audit processes of this kind of systems. To achieve this, a series of tests and experimental analysis are performed on two types of systems. The computational model is able to predict the effectiveness of the system and the main variables at the system exhaust as temperature and humidity by using the measurement of temperature and mass flow rates that participle in the energy and mass and transfer. The key in the analysis is the global heat transfer coefficient AU, considering the influence of the water an air mass flow rates in the system. An example of each system considered in this study is shown, illustrating the validation of the model. [ABSTRACT FROM AUTHOR]
- Published
- 2010
30. Modelo computacional para la formación de clases de equivalencia.
- Author
-
García, Andrés García, Martín Hernández, José Antonio, and Gutiérrez Domínguez, María Teresa
- Subjects
- *
INTERPERSONAL relations , *CONDITIONED response , *SIMULATION methods & models , *BEHAVIORAL assessment , *PSYCHOLOGY - Abstract
A computational model of neuronal net closely related with the formation of equivalence classes is developed. First the formal pattern of the neuronal net is presented and then its operation and its direct relationship with the phenomenon of the formation of the equivalence classes and with the derived relationships are explained. Later on, the validation of the pattern is described carrying out several simulations allowing verification of the pattern so it is able to generate relationships not explicitly trained, these results being adjusted to the basic results of this investigation line. These simulations were carried out using a training of classic conditioning and a test phase by means of conditional discriminations. [ABSTRACT FROM AUTHOR]
- Published
- 2010
31. Análisis del Shell de la Prensa de Vacío para una Planta Productora de Papel.
- Author
-
Isidro García, José, Valdés, Jairo, and Galvis, Elmer
- Subjects
- *
VACUUM , *STRUCTURAL engineering , *GRINDING & polishing , *ARCHITECTURE - Abstract
A Structural Analysis was made in this work to determine the state of deformations and stresses for the vacuum press shell under normal operating conditions. Once the deformations and stresses distributions were known, a fatigue analysis was made to evaluate the convenience of future surface grinding operations. The maximum deflection calculated in the model was in accordance with the real setting for the couch roll crown currently in use, which secures a contact NIP that is approximately constant along the axial direction. [ABSTRACT FROM AUTHOR]
- Published
- 2003
32. Desenvolvimento do sistema de suspensão para o carro IFS03EE
- Author
-
Carpinteiro, João Eduardo Alves Canas Palma, Portal, Ricardo José Fontes, and Leite, Afonso Manuel da Costa de Sousa
- Subjects
Dinâmica de veículo ,Suspension geometry ,Motorsport ,Shock absorber curve ,Computational model ,Geometria de suspensão ,Modelo computacional ,Tire test data ,Competição automóvel ,Vehicle dynamics ,Modelo de veículo ,Matlab Simulink ,Formula estudante ,Curva de amortecimento ,Formula student ,Vehicle model ,Dados de ensaio dos pneumáticos - Abstract
Trabalho final de mestrado para obtenção do grau de mestre em Engenharia Mecânica Submitted by Sónia Mestre (sonia.mestre@isel.pt) on 2020-12-11T18:19:29Z No. of bitstreams: 1 Dissertação_2128.pdf: 5176767 bytes, checksum: 9cc8eb2c943ec299a911f9d5b8e55183 (MD5) Made available in DSpace on 2020-12-11T18:19:29Z (GMT). No. of bitstreams: 1 Dissertação_2128.pdf: 5176767 bytes, checksum: 9cc8eb2c943ec299a911f9d5b8e55183 (MD5) Previous issue date: 2019-12-04 N/A
- Published
- 2019
33. Aplicação da dinâmica de sistemas na implementação de modelo computacional para estimação da qualidade do efluente de lagoas facultativas
- Author
-
Logatti, Bruna and Kellner, Erich
- Subjects
Qualidade do efluente ,Stabilization pond ,ENGENHARIAS ,Computational model ,ENGENHARIA SANITARIA [ENGENHARIAS] ,ENGENHARIA SANITARIA::TRATAMENTO DE AGUAS DE ABASTECIMENTO E RESIDUARIAS [ENGENHARIAS] ,Modelo computacional ,ENGENHARIA CIVIL::ENGENHARIA HIDRAULICA [ENGENHARIAS] ,Lagoa de estabilização ,ENGENHARIA CIVIL::ENGENHARIA HIDRAULICA::HIDRAULICA [ENGENHARIAS] ,ENGENHARIA CIVIL [ENGENHARIAS] ,Effluent quality - Abstract
Não recebi financiamento This paper presents the preliminary results of the development of a computer model to predict the quality of the facultative pond effluent proposed by FRITZ (1985) with a system dynamics approach, using the software VenSim PLE ®. The model considers the mass balance applied in a complete mixing reactor, consisting of the simultaneous resolution of twelve differential equations in time for the determination of effluent concentrations of crude COD, soluble COD, dissolved oxygen, Organic and Inorganic Nitrogen, Total Kjeldhal Nitrogen, Ammoniacal Nitrogen, Organic and Inorganic Phosphorus, Alkalinity, Hydrogenionic Concentration (pH). For its calibration there was the division into two stages: verification and validation. For the verification, the following parameters were simulated: soluble COD, Ammoniacal Nitrogen, Total Phosphorus, pH, DO and temperature, were compared with the results obtained by Silva (1982) for a pilot scale facultative lagoon located in Campina Grande (PB), which operates as a complete mixing reactor and whose sampling were composed. The results of the simulations obtained for the verification were considered satisfactory, standing out the soluble COD, OD and temperature, which were similar to those obtained in the field. For validation, the following parameters were analyzed: crude COD, soluble COD, Kjeldhal Total Nitrogen, Ammoniac Nitrogen, pH, OD and Alkalinity, which were compared with the results obtained by Pedrelli (1997) for a full scale facultative lagoon located in Balneário Camburiú (SC). The results of the simulations obtained for Alkalinity and pH were the ones that presented the greatest similarity with those obtained in the field, soluble COD had satisfactory results, but for the other parameters the simulation results were slightly higher than those observed. Such variations may be associated to disregarding the variability of the affluent quality in the facultative pond, the possibility of compartmentalization of the liquid volume, which would remove the model from the complete mixing condition, as well as the fact that the samples used in the validation were obtained punctually and not in a compound way. Este trabalho apresenta os resultados do desenvolvimento de modelo computacional para previsão da qualidade do efluente de lagoa facultativa, proposto por FRITZ (1985) com abordagem da dinâmica de sistemas, sendo utilizado o software VenSim PLE ®. O modelo considera o balanço de massa aplicado em um reator de mistura completa, consistindo na resolução simultânea de doze equações diferenciais no tempo para determinação das concentrações efluentes da DQO bruta, DQO solúvel, oxigênio dissolvido, Nitrogênio Orgânico e Inorgânico, Nitrogênio Total Kjeldhal, Nitrogênio Amoniacal, Fósforo Orgânico e Inorgânico, Alcalinidade, concentração hidrogeniônica (pH). Para a calibração do modelo, foram realizadas duas etapas: verificação e validação. Para a verificação foram feitas simulações para os parâmetros: DQO solúvel, Nitrogênio Amoniacal, Fósforo Total, pH, OD e temperatura, que foram comparados com os resultados obtidos por Silva (1982) para uma lagoa facultativa em escala piloto localizada em Campina Grande (PB) operada como um reator de mistura completa e amostragem composta. Os resultados das simulações obtidos para a verificação foram considerados satisfatórios, destacando-se a DQO solúvel, o OD e a temperatura, cujos resultados estavam similares com os obtidos em campo. Para validação foram realizadas simulações para os parâmetros: DQO bruta, DQO solúvel, Nitrogênio Total Kjeldhal, Nitrogênio Amoniacal, pH, OD e Alcalinidade, que foram comparados com os resultados obtidos por Pedrelli (1997) para uma lagoa facultativa em escala plena localizada em Balneário Camburiú (SC). Os resultados das simulações obtidos para Alcalinidade e pH foram os que apresentaram maior semelhança com os obtidos em campo. A comparação dos valores da DQO solúvel foram satisfatórios, porém para os demais parâmetros, os resultados da simulação foram ligeiramente superiores aos observados. Tais variações podem estar associadas à desconsideração da variabilidade da qualidade do afluente na lagoa facultativa, a possibilidade de ocorrência de compartimentalização do volume líquido, o que afastaria o modelo da condição de mistura completa, assim como o fato das amostras usadas na validação terem sido obtidas pontualmente e não de maneira composta.
- Published
- 2019
34. Correlação espaço-temporal da dengue e variáveis climáticas na cidade de São Paulo, Brasil
- Author
-
Marcio Luis Valença Araújo, Eduardo Manuel de Freitas Jorge, Marcelo A. Moret, Renelson Ribeiro Sampaio, Raphael Silva do Rosário, Aloisio S. Nascimento Filho, José Garcia Vivas Miranda, Antônio Cordeiro, Márcio C. F. Macedo, and Hugo Saba
- Subjects
Computational Model ,030231 tropical medicine ,Aedes aegypti ,010501 environmental sciences ,01 natural sciences ,Spearman's rank correlation coefficient ,Dengue fever ,03 medical and health sciences ,0302 clinical medicine ,Spatial temporal correlation ,parasitic diseases ,medicine ,Epidemic disease ,Socioeconomics ,Enfermedad epidémica ,0105 earth and related environmental sciences ,General Environmental Science ,biology ,Doença epidêmica ,Correlación ,virus diseases ,Climatic variables ,Correlação ,Modelo computacional ,medicine.disease ,biology.organism_classification ,Correlation ,Geography ,General Earth and Planetary Sciences - Abstract
This paper studies the association between dengue cases and climatic variables in the city of São Paulo, Brazil, in the period from 2001 to 2011. The main hypothesis is that climatic conditions, such as precipitation, humidity and temperature, are all correlated to the dengue spread in São Paulo. Randomization and Spearman rank correlation are applied over the collected dataset, and the estimated results show that only a higher temperature is correlated to an increase in the notification of new dengue cases in São Paulo, further reinforcing the fact that the Aedes aegypti mosquito is known to survive in distinct climatic conditions, greatly adapting itself to urban environments. Este trabajo estudia la asociación entre casos de dengue y variables climáticas en la ciudad de São Paulo, Brasil, en el período de 2001 a 2011. La principal hipótesis es que las condiciones climáticas, como precipitación, humedad y temperatura, están correlacionadas con el dengue. difundido en São Paulo. La aleatorización y la correlación de rango de Spearman se aplican sobre el conjunto de datos recopilados, y los resultados estimados muestran que solo una temperatura más alta se correlaciona con un aumento en la notificación de nuevos casos de dengue en São Paulo, lo que refuerza aún más el hecho de que se sabe que el mosquito Aedes aegypti sobrevive en distintas condiciones climáticas, adaptándose en gran medida a los entornos urbanos. Este trabalho estuda a associação entre casos de dengue e variáveis climáticas na cidade de São Paulo, Brasil, no período de 2001 a 2011. A principal hipótese é que as condições climáticas, como precipitação, umidade e temperatura, estão todas relacionadas à dengue disseminada em São Paulo. A randomização e a correlação de Spearman são aplicadas sobre o conjunto de dados coletado, e os resultados estimados mostram que apenas uma temperatura mais alta está correlacionada a um aumento na notificação de novos casos de dengue em São Paulo, reforçando ainda mais o fato de que o mosquito Aedes aegypti é conhecido por sobreviver em condições climáticas distintas, adaptando-se enormemente aos ambientes urbanos.
- Published
- 2021
- Full Text
- View/download PDF
35. GeNeSys - sistema de co-evolución genética y neuro-memética para la auto-organización senso-motriz y conductual en una sociedad de robots
- Author
-
Sterpin Buitrago, Dante Giovanni, González Guerrero, Enrique, Flórez Valencia, Leonardo, and Gerlein Reyes, Eduardo Andrés
- Subjects
Aprendizaje extremo ,Self-supervised learning ,Computación memética ,Aprendizaje por refuerzo continuo ,Computational model ,Multi-agent systems ,Memetic computation ,Modelo computacional ,Simulación por computadores ,Extreme learning machines ,Control proporcional-derivativo ,Gene-culture co-evolution ,Neuro-memetic replication ,Evolutionary robotics ,Co-evolución gene-cultura ,Memes and neuro-memes ,Aprendizaje auto-supervisado ,Maestría en ingeniería de sistemas - Tesis y disertaciones académicas ,Memes y neuro-memes ,Replicación neuro-memética ,Sistemas multi-agente ,Robótica evolutiva ,Proportional-derivative control ,Continuous reinforcement learning - Abstract
Bio-inspired computing can be used to model natural and social systems, including societies with cultural development. Currently, two positions on cultural evolution stand out: with and without replicators. The existence of memes, as cultural replicators, is still hypothetical, and it seems better to look for them in the brain, because they can only be: neuro-memes. In literature there are only two models inspired by the neuro-memetics, and culture evolves side by side with genetics, so it’s necessary to model a gene-culture co-evolution, with neuro-memes. Such a model would be used to help validate the neuro-memetics, on the one hand, and on the other hand, it would help to understand and heal serious problems in human societies. Here, a genetic and neuro-memetic co-evolutionary system was achieved, and a robotic society used it for survive by developing behavioural patterns as a cultural tradition. La computación bio-inspirada puede ser empleada para modelar sistemas naturales y sociales, entre los cuales están las sociedades con desarrollo cultural. En la actualidad, sobresalen dos posturas sobre la evolución cultural: con y sin replicadores. La existencia de memes, como replicadores culturales, es aún hipotética, y parece mejor buscarlos en el cerebro, porque solo pueden ser: neuro-memes. En la literatura hay apenas dos modelos inspirados en la concepción neuro-memética, y como la evolución cultural va de la mano con la genética, se requiere entonces modelar una co-evolución gene-cultura, basada en neuro-memes. Un modelo así, se usaría para ayudar a validar la hipótesis neuro-memética, por un lado, y por el otro, ayudaría a comprender y atender serias problemáticas en las sociedades humanas. Con este proyecto se logró un sistema de co-evolución genética y neuro-memética, que fue usado por una sociedad de robots para sobrevivir, desarrollando un comportamiento cultural. Magíster en Ingeniería de Sistemas y Computación Maestría
- Published
- 2019
36. Simulation of human gait using real data in a computational exoskeleton model for lower limb
- Author
-
Britos, Ezequiel, Politti, Julio César, and Herrera de Olivera, Myriam Cristina
- Subjects
ANGULOS DE ROTACION DE LAS ARTICULACIONES ,COMPUTATIONAL MODEL ,GATE CYCLE ,purl.org/becyt/ford/2.6 [https] ,HANNAVAN'S MODEL ,Otras Ingeniería Médica ,INGENIERÍAS Y TECNOLOGÍAS ,EXOESKELETON ,purl.org/becyt/ford/2 [https] ,MODELO HANNAVAN ,EXOESQUELETO ,Ingeniería Médica ,ANGLE ROTATIONS JOINTS ,MODELO COMPUTACIONAL ,CICLO DE MARCHA - Abstract
En este trabajo se obtuvieron los torques (momentos de fuerza) ejercidos por las articulaciones de los miembros inferiores (articulación de la cadera y rodilla) a través de una simulación del ciclo de la marcha sobre un modelo computacional de un exoesqueleto de 4 grados de libertad. Se utilizaron datos reales obtenidos en un laboratorio de análisis de la marcha. El modelo computacional del exoesqueleto fue diseñado en SolidWorks® utilizando los datos antropomórfico del sujeto que realizó la caminata en el laboratorio. Se usó el modelo de Hannavan para la determinación de las propiedades inerciales y másicas delmodelo. Los datos fueron procesados en MATLAB®y los ángulos de rotación de las articulación de la cadera y la rodilla fueron obtenidos tanto para el miembro derecho como izquierdo en cada punto de la marcha. Los mismos fueron ingresados al software comercial MSC ADAMS®donde se llevó a cabo al simulación. De esta forma fue posible dimensionar los actuadores que se van a utilizar en la construcción del exoesqueleto. In this work, the torques (moments of forces) were obtained that perform the joints of the lower limbs (hip and knee) through a simulation of the gait cycle in a computational model of a 4 degree freedom exoskeleton. Real data obtained from a gait analysis laboratory were used. The computational model of the exoskeleton used was designed in SolidWorks® software with the anthropomorphic data of the subject from which the gait cycle data were obtained. For the determination of the inertial and mass properties of the model, the Hannavan model was used. The data were processed using MATLAB® and the rotation angles of the hip and knee joints were obtained for the right and left lower limbs at each time point in the cycle. The processed data were entered into the MSC ADAMS®, commercial software for the design and study of mechanical parts, where the corresponding simulations were performed. In this way, it was possible to size the actuators to be used in the later construction of the exoskeleton. Fil: Britos, Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería; Argentina Fil: Politti, Julio César. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería; Argentina Fil: Herrera de Olivera, Myriam Cristina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina
- Published
- 2018
37. Análisis computacional de la mutación c.1349_1352delAGTA en el gen fumarato hidratasa causante de HLRCC: implicaciones en la estructura proteica y en el metabolismo celular
- Author
-
Cardona Barreto, Andrea Yimena, Pinzón Velasco, Andrés Mauricio, and Arteaga Díaz, Clara Eugenia
- Subjects
Computational model ,Cardiolipina ,Molecular docking ,Cardiolipin ,57 Ciencias de la vida ,Biología / Life sciences ,biology ,Modelo computacional ,Tiorredoxina ,Thioredoxin ,HLRCC ,Fumarate hydratase ,Fumarato hidratasa ,Docking molecular - Abstract
Introducción: el gen FH codifica la enzima fumarato hidratasa y mutaciones en éste provocan el síndrome de leiomiomatosis hereditaria y cáncer de células renales (HLRCC). Objetivo: predecir computacionalmente los posibles cambios estructurales de la proteína fumarato hidratasa relacionados con la mutación c.1349_1352delAGTA en el gen FH causante del síndrome HLRCC, así como la posible implicación de estos cambios en el metabolismo celular. Metodología: se realizaron análisis estructurales de la proteína fumarato hidratasa con la mutación c.1349_1352delAGTA. Posteriormente, se llevó a cabo una simulación de interacción molecular con sus sustratos, mediante el programa AutoDock Vina. Finalmente, tomando como base la reconstrucción metabólica de humano: Recon 2 y mediante el paquete de análisis COBRA Toolbox, se modelaron computacionalmente las posibles implicaciones, a nivel metabólico, de distintos escenarios de actividad enzimática de la fumarato hidratasa. Resultados: De acuerdo con los resultados obtenidos mediante la simulación de interacción molecular, en donde se obtuvieron unas energías de -4.5 y -4.4 kcal/mol para la proteína silvestre y mutada con el fumarato respectivamente y de -4.8 y -4.4 kcal/mol para la proteína silvestre y mutada con el malato respectivamente, no se encontraron diferencias significativas entre estas energías. Nuestros resultados sugieren que la mutación c.1349_1352delAGTA en el gen FH podría tener su efecto entonces, al imposibilitar la oligomerización de la proteína durante el establecimiento de puentes de hidrogeno, y de esta manera se inhibiría la formación del sitio activo. En cuanto a las implicaciones a nivel metabólico de esta posible inhibición de formación del sitio activo, nuestros resultados sugieren un aumento en la reacción de biomasa, lo cual podría sugerir un mecanismo relacionado con cáncer y crecimiento tumoral. Además, se encontró una baja producción del fosfolipido cardiolipina lo que genera alta producción de especies reactivas de oxígeno y se encontró un aumento en el flujo desde el citoplasma hacia la mitocondria de la enzima tiorredoxina reductasa, implicada en la disminución en la actividad de la cascada de señalización de apoptosis. Abstract: Introduction: FH gene encodes the fumarate hydratase enzyme. Mutations in this gene can cause the hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome. Objective: to predict computationally, the possible structural changes of the fumarate hydratase protein related to the mutation c.1349_1352delAGTA in the FH gene that causes the HLRCC syndrome, as well as the possible implication of these changes in the cellular metabolism. Methodology: structural analyzes of the fumarate hydratase protein containing the mutation c.1349_1352delAGTA were made. Subsequently, molecular interaction simulation of the protein together with its substrates was carried out by using AutoDock Vina program. Finally, based on the metabolic human reconstruction: Recon 2 and through the COBRA Toolbox analysis package, the possible implications at the metabolic level of different scenarios of enzymatic activity of fumarate hydratase were computationally modeled. Results: According to the results obtained by the simulation of molecular interaction, were found energies values of -4.5 and -4.4 obtained for the wild and mutated protein with fumarate respectively and -4.8 and -4.4 for the wild protein and mutated with the malate respectively. No significant differences were found between the energy values obtained in none of the cases. In this way, our results suggest that the mutation c.1349_1352delAGTA in the FH gene could have its effect then, by making oligomerization of the protein impossible during the establishment of hydrogen bonds, and in this way the formation of the active site would be inhibited. Regarding the implications at the metabolic level of the possible inhibition of the active site formation, our results suggest an increase in the biomass reaction, which could suggest a mechanism related to cancer and tumor growth. In addition, a low production of the cardiolipin enzyme was found, which generates high production of reactive oxygen species; furthermore, it was found an increase in the flow of the reduce thioredoxin enzyme from the cytoplasm to the mitochondria, implied in the decrease in the apoptosis signaling cascade. Maestría
- Published
- 2018
38. Estudio de la dinámica de los niveles de glucosa de un paciente sano mediante el modelo de Dalla-Mann
- Author
-
Ibáñez Felipe, Jorge
- Subjects
Modelo de Dalla Man ,Java programming ,Insulina ,Computational model ,Grado en Ingeniería Informática-Grau en Enginyeria Informàtica ,Programación Java ,Modelo Computacional ,Insulin ,Glucose levels ,Dalla Man model ,Niveles de glucosa ,MATEMATICA APLICADA - Abstract
[ES] En un momento en que el grado de incidencia de la diabetes no hace sino aumentar año a año, el objeto de este trabajo es observar y analizar el modelado del comportamiento del organismo de una persona sana, de modo que podamos evaluar la utilidad del modelo metabólico de Dalla Mann et al. (que describe la asimilación y procesado de la glucosa en el cuerpo) sobre pacientes reales, esto es, que se pueda personalizar el modelo, con la esperanza de contribuir así a la prevención y tratamiento de esta enfermedad., [EN] At a time when the diabetes incidence degree increases year to year, the purpose of this work is to observe and analyze the metabolism behavior model of a healthy person, so we can see the usefulness of the mathematical-physiological model of Dalla Man et al. (which describes the assimilation and processing of glucose in the human body) in real patients, that is, if it is possible to customize the model, with the aim of contributing to prevention and treatment of this disease.
- Published
- 2018
39. Aproximações dos modelos de Hodgkin-Huxley e FitzHugh-Nagumo usando equações diferenciais com atraso
- Author
-
Rameh, Raffael Bechara, Santos, Rodrigo Weber dos, Rocha, Bernardo Martins, and Oliveira, Rafael Sachetto
- Subjects
Delay differential equation ,Computational model ,Potencial de ação ,Modelo computacional ,Action potential ,Hodgkin-Huxley ,Neuron ,Neurônio ,CIENCIAS EXATAS E DA TERRA [CNPQ] ,FitzHugh-Nagumo ,Equação diferencial com atraso - Abstract
Para representar diferentes fenômenos e sistemas modelos matemáticos são largamente utilizados. Muitos deles são fundamentados em sistemas de equações diferenciais ordinárias (EDOs), isto é, baseiam-se em conjuntos de igualdades que envolvem variáveis dependentes, suas derivadas de primeira ordem e a variável independente. Neste trabalho, estudamos a modelagem da geração do potencial de ação em células excitáveis, como os neurônios. Existem dois modelos tradicionais e pioneiros que se destacam nessa área: Hodgkin-Huxley e FitzHugh-Nagumo. O objetivo desta dissertação é avaliar a possibilidade de modelar a geração do potencial de ação via uma única equação diferencial com atraso. Equações diferenciais com atraso são importantes por sua capacidade em reproduzir uma grande diversidade de fenômenos. Porém, seu uso na modelagem do potencial de ação de células excitáveis é ainda incipiente. Nesta dissertação, o método usado para alcançar este objetivo se baseou no desenvolvimento, inicialmente, de uma equação integro-diferencial que aproxima o sistema de EDOs. Em seguida, desenvolvemos uma aproximação para as integrais que usa termos tanto no instante atual quanto em instante anteriores, i.e., atrasados no tempo. Dessa forma, mostramos que é possível aproximar cada um dos sistemas de EDOS dos modelos de Hodgkin-Huxley e FitzHugh-Nagumo por uma única equação diferencial com atraso. Por fim, estes novos modelos são comparados com os originais, e são apontadas direções para a continuidade desta pesquisa. To represent different phenomena and systems mathematical models are widely used. Many of them are based on systems of ordinary differential equations (ODEs), that is, they are based on sets of equalities involving dependent variables, their derivatives of first order and the independent variable. In this work, we study the modeling of action potential generation in excitable cells, such as neurons. There are two traditional and pioneering models that stand out in this area: Hodgkin-Huxley and FitzHugh-Nagumo. The objective of this dissertation is to evaluate the possibility of modeling the generation of the action potential via a single differential equation with delay. Differential equations with delay are important because of their capacity to reproduce a great diversity of phenomena. However, its use in modeling the action potential of excitable cells is still incipient. In this dissertation, the method used to achieve this goal was based on the development, initially, of an integral-differential equation that approximates the ODE system. Next, we develop an approximation for integrals that uses terms at both the current instant and the previous instant, i.e., time delayed. Thus, we show that it is possible to approximate each of the ODEs systems of the Hodgkin-Huxley and FitzHugh-Nagumo models by a single differential equation with delay. Finally, these new models are compared with the original ones, and directions are indicated for future works.
- Published
- 2018
40. Altered colour induction in migraine : computational simulation and psychophysical results
- Author
-
Sallent Ruiz, Nilai, Universitat Autònoma de Barcelona. Escola d'Enginyeria, Cerdà Company, Joaquin, and Otazu Porter, Xavier
- Subjects
Contrast sensitivity function ,Computational model ,Inducció de color ,Modelo computacional ,Función de sensibilidad al contraste ,Psicofísica ,Migranya ,Psychophysics ,Colour induction ,Funció de sensibilitat de contrast ,Migraña ,Migraine ,Model computacional ,Inducción de color - Abstract
Migraine is a usual headache disorder associated to differences in visual perception. Recent findings suggest that migraineurs could have a deficit in the inhibitory mechanism which plays an important role in visual perception. Colour induction is the influence of the surrounding colour (inducer) on the perceived colour of a central region. There are two types of induction: colour assimilation and colour contrast, and it has been widely studied in non-migraine subjects. This work extends the psychophysical results of Otazu et al. (2010) by adding new experiments with migraine subjects. Because of the deficit in inhibition, we expect that migraine subjects show the weakest assimilation. Our results show the opposite effect. For striped surround, the strongest assimilation is found in migraine without aura subjects. In uniform surround, the highest contrast is observed in both migraine groups. In all conditions control subjects show the weakest induction. La migranya és un transtorn de mal de cap comú associat a diferències en la percepció visual. Descobriments recents suggereixen que els migranyosos poden tenir un dèficit en el mecanisme neuronal d'inhibició que juga un paper important en la percepció visual. La inducció del color es la influència del color circumdant (inductor) al color percebut d'una regió central. Hi ha dos tipus d'inducció: assimilació del color i contrast del color, i s'han estudiat extensament en subjectes sense migranya. Aquest treball amplia els resultats psicofísics de Otazu et al. (2010) afegint nous experiments amb migranyosos (amb i sense aura). A causa del dèficit inhibitori, esperem que els subjectes amb migranya mostrin la menor assimilació. Els nostres resultats mostren l'efecte contrari. Per a voltants ratllats, l'assimilació més forta es troba a la migranya sense aura. En voltants uniformes, s'observa el major contrast en ambdós grups de migranyosos. En totes les condicions, els subjectes de control presenten una menor inducció. La migraña es un trastorno de dolor de cabeza común asociado a diferencias en la percepción visual. Descubrimientos recientes sugieren que los migrañosos pueden tener un déficit en el mecanismo neuronal de inhibición que juega un papel importante en la percepción visual. La inducción del color es la influencia del color circundante (inductor) el color percibido de una región central. Hay dos tipos de inducción: asimilación del color y contraste del color, y se han estudiado extensamente en sujetos sin migraña. Este trabajo amplía los resultados psicofísicos de Otazu et al. (2010) añadiendo nuevos experimentos con migrañosos (con y sin aura). Debido al déficit inhibitorio, esperamos que los sujetos con migraña muestren la menor asimilación. Nuestros resultados muestran el efecto contrario. Para alrededores rayados, la asimilación más fuerte se encuentra en sujetos de migraña sin aura. En inmediaciones uniformes, se observa el mayor contraste en ambos grupos de migrañosos. En todas las condiciones, los sujetos de control presentan una menor inducción.
- Published
- 2018
41. Development of the from a strong structure in computer design
- Author
-
Morales Guzmán, Carlos César, Martínez Cruz, Calixto, Rivera Torre, Héctor, and Flores Gutierrez, Avatar
- Subjects
computational model ,modelo computacional ,metodología del diseño ,geometría aplicada ,metodologia de projeto ,geometria aplicada ,design methodology ,applied geometry - Abstract
El origen de la investigación se desarrolla en la metodología de traslación geométrica de una superficie mínima, la incógnita, es elaborar una metodología de diseño que se ajuste a un programa virtual y éste, desarrolle el diseño físico de los modelos de tenso estructuras, del que pueden resultar una variedad de formas. La difícil transición de la forma, es la aplicación del patronaje, ya que el sistema se somete a las medidas constructivas del material, para ello se desarrolla un método que generará simulaciones geométricas, creando diseños de velarías de una forma más sencilla, mediante un software de uso común. The origin of the research is developed in the methodology of geometrical translation of a minimum surface, the unknown, is to develop a design methodology that fits a virtual program and this, develop the physical design of the models of tense structures, which may result in a variety of forms. The difficult transition of the form, is the application of the pattern, since the system is subjected to the constructive measures of the material, for it is developed a method that will generate geometric simulations, creating designs of tense structures in a simpler way, using software of common use. A origem da pesquisa é desenvolvida na metodologia de tradução geométrica de uma superfície mínima, o desconhecido, é desenvolver uma metodologia de design que se encaixa em um programa virtual e, desenvolver o design físico dos modelos de estruturas tensas, que pode resultar em uma variedade de formas. A difícil transição da forma, é a aplicação do padrão, uma vez que o sistema é submetido às medidas construtivas do material, pois desenvolve um método que irá gerar simulações geométricas, criando projetos de velarías de forma mais simples, por meio de software de uso comum.
- Published
- 2017
42. Computational model of the effect of alpha oscillatory phase on the timing of neuronal activations and resulting motor responses
- Author
-
Velez, Lea Cristele Rosa, Ribeiro, Maria José Braga Marques, and Branco, Miguel Sá Sousa Castelo
- Subjects
reaction time ,neuroscience ,neurociências ,computational model ,processamento sensorial ,modelo computacional ,tempo de reacção ,sensory processing ,oscilações alfa ,alpha oscillations - Abstract
Trabalho de Projeto do Mestrado Integrado em Engenharia Biomédica apresentado à Faculdade de Ciências e Tecnologia O comportamento humano varia de um momento para o outro. Na realidade, quando uma tarefa sensório-motora é repetida várias vezes, os tempos de reacção de um sujeito variam ao longo da tarefa. Esta alta variabilidade, para cada sujeito, que existe no tempo de resposta comportamental humana, tem motivado investigadores a estudar os mecanismos que estão por trás da cognição e processamento de estímulos sensoriais. Os modelos de tempo de reacção actuais atribuem como causa desta variabilidade a variabilidade no processo de acumulação de evidência, antes da formulação de uma resposta. No entanto, descobertas recentes sugerem que a fase de oscilação das ondas alfa no cérebro modulam o tempo de activação das populações neuronais, abrindo a possibilidade de esta variabilidade nos tempos de reacção surgir da variabilidade nos tempos de transmissão de informação no cérebro. Aqui propomos um modelo computacional focado neste mesmo aspecto, simulando os mecanismos neurais por trás da transmissão de informação durante o processamento sensorial no cérebro, e assumindo uma activação de populações neuronais dependente da fase das ondas alfa. Notavelmente, o nosso modelo conseguiu prever associações importantes entre a frequência das ondas alfa e os tempos de reacção. Para além disso, conseguimos fazer o ajuste, com sucesso, de dados de tempo de reacção simulados a dados de tempo de reacção empíricos obtidos usando duas tarefas experimentais (“simple RT” e “go/no-go”), com sujeitos de dois grupos etários (jovens adultos e adultos seniores). Nesta análise, obtivemos diferenças nos parâmetros do modelo que aparentam estar de acordo com o que se sabe da literatura sobre as diferenças de processamento neuronal nestes dois tipos de tarefas experimentais. Human behaviour presents high moment-to-moment variability. In fact, when repeatedly performing the same sensorimotor task, subjects’ response times vary from one moment to the next. This high within-subject variability in human behavioural response timing has long encouraged researchers to uncover the underlying mechanisms of cognition and sensory stimulus neural processing. Current reaction time (RT) models attribute the source of this variability to variability in the evidence accumulation process, before making a response. Yet, recent findings suggest that the phase of alpha oscillations in the brain modulates the timing of neuronal population activity, opening the possibility that, in alternative to current models, reaction time variability arises from variability in the timing of information transmission in the brain. We propose a computational model focusing on this very aspect, by simulating the neural mechanisms behind information transmission during sensory processing in the brain, while focusing on an alpha oscillatory phase-dependent neuronal population activation. Notably, our model was able to predict important associations between alpha oscillations and response times. Furthermore, we were able to successfully fit our simulated data to empirical RT data from two auditory tasks (simple RT and go/no-go), with subjects from two different age groups (young and older adults), and obtained differences in the model’s parameters that appear to align with what is known from the literature.
- Published
- 2017
43. Computational knowledge-based model for three-dimensional postural assessment
- Author
-
Sant'Ana, Hugo Gustavo Franco, Machado, Aydano Pamponet, Costa, Evandro de Barros, and Bispo, Rodrigo Freitas Monte
- Subjects
Computerized biophotogrammetry ,Fotogrametria ,Biofotogrametria computadorizada ,Photogrammetry ,Human posture ,Computational model ,CIENCIAS EXATAS E DA TERRA::CIENCIA DA COMPUTACAO [CNPQ] ,Postura humana ,Modelo computacional ,Software - Abstract
It is well established in the literature the importance of the posture characterization for a good kinetic-functional diagnosis, identifying and measuring postural changes and muscle imbalances allowing the adequate elaboration of rehabilitation programs. To facilitate the action of the specialist, computer programs were developed for three-dimensional analyzes of the curvatures of the spine from two-dimensional images. Such methods have limitations, even with technological evolution, including the most recent methods with the use of three-dimensional capture for the evaluation of muscular imbalances. Thus, there is an urgent need to improve the methods used to evaluate postural changes, correcting the limitations and improving existing techniques for identifying asymmetries, spinal deviations and alterations in peripheral joints. This study is a methodological research of development With the general aim of proposing a knowledge-based computer model for three-dimensional postural evaluation. And, specific objectives: to develop new algorithms or to perfect those that already exist for a postural analysis based on Cartesian coordinates in three dimensions; Propose a knowledge-based computer model that minimizes the limitations of existing methods; Test the implementation of the model through a pilot study. Finally, the study showed that, the proposed model intends to solve part of the limitations that the current computer tools for the biophotogrammetric evaluation bear. Está bem estabelecida na literatura a importância da caracterização da postura para um bom diagnóstico cineticofuncional, identificando e mensurando as alterações posturais e os desequilíbrios musculares permitindo a elaboração adequada de programas de reabilitação. Para facilitar a ação do especialista, programas computacionais foram desenvolvidos para análises tridimensionais das curvaturas da coluna vertebral a partir de imagens bidimensionais. Tais métodos apresentam limitações, mesmo com a evolução tecnológica, inclusive os métodos mais recentes com a utilização de captura tridimensional para avaliação dos desequilíbrios musculares. Sendo assim, urge a necessidade de aperfeiçoar os métodos utilizados para a avaliação das alterações posturais, corrigindo as limitações e aperfeiçoando as técnicas existentes para identificação das assimetrias, desvios na coluna e alterações nas articulações periféricas. Esse estudo trata-se de uma pesquisa metodológica de desenvolvimento com o objetivo geral de propor um modelo computacional baseado em conhecimento para avaliação postural tridimensional. E, objetivos específicos: desenvolver algoritmos novos ou aperfeiçoar os que já existem para uma análise postural baseada nas coordenadas cartesianas em três dimensões; propor um modelo computacional baseado no conhecimento que minimize as limitações dos métodos já existentes; testar a implementação do modelo através de um estudo piloto. Por fim, o estudo mostrou que, o modelo proposto pretende resolver parte das limitações que as atuais ferramentas computacionais para a avaliação biofotogramétrica.
- Published
- 2017
44. Análise econômica para o dimensionamento da colheita mecanizada de cana-de-açúcar (Saccharum spp.)
- Author
-
Casimiro Dias Gadanha Júnior, Neisvaldo Barbosa Dos Santos, Rouverson Pereira da Silva, Universidade de São Paulo (USP), and Universidade Estadual Paulista (Unesp)
- Subjects
Engineering ,modelo computacional ,Process (engineering) ,Agriculture (General) ,media_common.quotation_subject ,Agricultural engineering ,Raw material ,agricultural mechanization ,S1-972 ,sugarcane harvester ,Saccharum ,Quality (business) ,Cane ,Agribusiness ,media_common ,biology ,business.industry ,mecanização agrícola ,biology.organism_classification ,Agricultural and Biological Sciences (miscellaneous) ,Sizing ,computational model ,Work (electrical) ,colhedora de cana ,business - Abstract
Made available in DSpace on 2015-02-02T12:39:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-10-01Bitstream added on 2015-02-02T13:08:13Z : No. of bitstreams: 1 S0100-69162014000500013.pdf: 314340 bytes, checksum: e5286502122dcd6d1c6abb8ffcf423fb (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) A cultura da cana-de-açúcar tem significativa participação na economia do agronegócio brasileiro. A colheita de cana é considerada como uma das operações mais importantes, pois deve atender à demanda de matéria-prima requerida pela Usina com qualidade e custo competitivo. O objetivo deste trabalho foi analisar, de modo sistêmico, a influência das variáveis no desempenho operacional e econômico do processo de colheita mecanizada da cana-de-açúcar para o dimensionamento das máquinas. Para tanto, foi desenvolvido um modelo, denominado de ColheCana, em planilha eletrônica e em linguagem de programação. Os resultados evidenciaram que a eficiência de campo e o valor inicial das colhedoras são variáveis de grande impacto no custo e que existe uma área máxima a que um equipamento pode atender para a qual o custo é mínimo. Sugarcane has a significant role on Brazilian agribusiness economy. The harvesting cane is considered as one of the most important operations of the process for it has to attend the raw material demanded by the sugar mill in quality and a competitive cost. The objective of this work it is it of analyzing, of systemic way, the variables influence on economical and operational performance in sugarcane mechanized harvesting process for sizing of machines. For this purpose a model called ColheCana, was developed in a spreadsheet and in a programming language. The results showed that the field efficiency and harvester´s initial value are variables of great impact in the cost and that there is a maximum area that one equipment can attend and for this area the cost is minimum. USP ESALQ UNESP Departamento de Engenharia Rural Escola Superior de Agricultura Luiz de Queiroz Faculdade de Ciências Agronômicas UNESP Departamento de Engenharia Rural
- Published
- 2014
- Full Text
- View/download PDF
45. SIA: Model for simulation of sprinkler irrigation - Calibration and validation
- Author
-
Lessandro Coll Faria, Giuliani do Prado, Samuel Beskow, Alberto Colombo, and Henrique Fonseca Elias de Oliveira
- Subjects
gun sprinkler ,computational model ,Environmental Engineering ,canhão hidráulico ,modelo computacional ,uniformidade ,wind ,vento ,uniformity ,Agronomy and Crop Science - Abstract
A maioria dos modelos matemáticos de simulação da aplicação de água por aspersores requer trabalhos laboriosos de calibração e validação, além de exigir, dos computadores, elevada capacidade de processamento. Este estudo foi realizado com o objetivo de calibrar e validar o modelo Simulação da Irrigação por Aspersão (SIA) no que se refere à operação de canhões hidráulicos em condições reais de campo. O método de otimização global Shuffled Complex Evolution (SCE-UA) foi implementado no SIA com o intuito de ajustar os parâmetros de calibração baseados no modelo semiempírico de Richards & Weatherhead utilizando-se ensaios de campo do canhão Plona - RL250. Os parâmetros obtidos na calibração para determinada configuração do aspersor, foram mantidos constantes e posteriormente usados na validação para diferentes condições operacionais e de vento. O Método Shuffled Complex Evolution apresentou elevados índices de qualidade do ajuste além de rápida convergência. O modelo SIA foi capaz de prever a taxa de aplicação de água do canhão hidráulico Plona-RL250 e a uniformidade de distribuição de água do sistema, de forma adequada tanto no estágio de calibração quanto no de validação. Great majority o mathematical simulation models of water application by sprinkler requires laborious tasks of calibration and validation and high processing power of computers as well. This study was conducted in order to calibrate and validate the SIA - Simulation Model for Sprinkler Irrigation, referring to the operation of rain guns in real field conditions. The Shuffled Complex Evolution (SCE-UA) global optimization method was implemented in the SIA, aiming for adjusting the calibration parameters, based on the semi empirical model of Richards & Weatherhead, using field tests from PLONA - RL250 rain gun. The parameters obtained through calibration, for a given configuration of the sprinkler, were kept constant and, subsequently, used in validation for different wind and operating conditions. The Shuffled Complex Evolution (SCE-UA) method showed high level of adjustment quality and fast convergence. The SIA model was able to predict the rate of a PLONA - RL250 rain gun application and uniformity of water distribution system adequately both in calibration stage as well as in validation stage.
- Published
- 2013
- Full Text
- View/download PDF
46. Biomechanical changes after in vivo collagen cross-linking with rose bengal–green light and riboflavin-UVA
- Author
-
Susana Marcos, Nandor Bekesi, Irene E. Kochevar, Patricia Gallego-Muñoz, M. Carmen Martínez-García, Lucía Ibares-Frías, Pablo Pérez-Merino, European Commission, Comunidad de Madrid, Ministerio de Economía y Competitividad (España), and SCOAP
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Collagen cross linking ,Scheimpflug principle ,Corneal collagen cross-linking ,Riboflavin ,Técnica de cross-linking ,03 medical and health sciences ,chemistry.chemical_compound ,Corneal biomechanics ,0302 clinical medicine ,In vivo ,Cornea ,Ophthalmology ,Rose bengal ,Medicine ,business.industry ,2209.15 Optometría ,Computational model ,Computational modeling ,Inverse model ,Modelo computacional ,Inverse modeling ,3. Good health ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,030221 ophthalmology & optometry ,sense organs ,Cross-linking technique ,Biomecánica corneal ,business ,Modelo inverso ,Ex vivo ,Cross-linking - Abstract
Producción Científica, Purpose: To compare corneal biomechanical properties after in vivo and ex vivo cross-linking (CXL) using rose bengal–green light (RGX) or riboflavin-UVA (UVX). Methods: Corneas of 30 rabbits were treated in vivo by the two CXL modalities monolaterally (Group 1) or bilaterally (Group 2). Rabbits in Group 1 were euthanized 1 month after treatments and in Group 2 two months after treatment. Ex vivo CXL was also performed. Eyes were measured by Scheimpflug air puff corneal deformation imaging (Corvis ST) under constant IOP. Corneal deformation parameters were assessed. Inherent corneal biomechanical properties were estimated using inverse finite element modeling. Results: Peak to peak distance decreased 16% 2 months after RGX, and 4% and 20% 1 and 2 months after UVX, respectively. The equivalent Young's modulus (Eeq) increased relative to the control during the post treatment period for both RGX and UVX. The Eeq increased by factors of 3.4 (RGX) and 1.7 (UVX) 1 month and by factors of 10.7 (RGX) and 7.3 (UVX) 2 months after treatment. However, the Eeq values for ex vivo CXL were much greater than produced in vivo. The ex vivo Eeq was greater than the 1-month in vivo values by factors of 8.1 (RGX) and 9.1 (UVX) and compared with 2 month by factors of 2.5 (RGX) and 2.1 (UVX). Conclusions: These results indicate that corneal stiffness increases after CXL, and further increases as a function of time after both RGX and UVX. Also, while biomechanical properties determined after ex vivo CXL are indicative of corneal stiffening, they may not provide entirely accurate information about the responses to CXL in vivo., Consejo Europeo de Investigación (grant ERC-2011-AdC-294099), Comunidad de Madrid - Marie Curie COFUND program (grant FP7/2007-2013/REA 291820), Gobierno de España (grant FIS2014-56643-R)
- Published
- 2017
- Full Text
- View/download PDF
47. Educación filosófica y creatividad : descripción de un encuentro
- Author
-
González Gutiérrez, Leidy Carolina and García Rodríguez, Daniel
- Subjects
Creativity ,Philosophy for children (P4C) ,Filosofía para niños (FPN) ,Cognición ,Cognition ,Maestría en educación - Tesis y disertaciones académicas ,Philosophical education ,Computational model ,Educación filosófica ,Filosofía - Enseñanza ,Aptitud creadora ,Modelo computacional ,Creatividad - Abstract
La presente investigación tiene como objetivo identificar qué elementos, durante el desarrollo del diálogo mayéutico en una comunidad de investigación, permiten la exploración y evaluación del espacio conceptual como procesos necesarios para el desarrollo del pensamiento creativo. Para cumplir con este objetivo se utilizaron: el modelo de educación filosófica de Matthew Lipman, más conocido como (FpN) Filosofía para Niños, y el modelo computacional para el desarrollo de la creatividad de Margaret Boden. El proceso permitió formular algunas hipótesis sobre el valor de la educación filosófica a través del diálogo en la escuela como catalizador de procesos exploratorios y evaluativos para el desarrollo de la creatividad. The present investigation aims to identify, during the development of maieutic dialogues in a research community, which are the elements that allow the exploration and evaluation of the conceptual space as necessary processes to develop creative thinking as processes necessary for the development of creative thinking. In order to achieve the previous, Matthew Lipman' s philosophical education model, also known as (P4C) Philosophy for children, and Margaret Boden' s computational model to develop creativity were used. The process permitted to formulate some hypothesis concerning the value of philosophical education through dialogue as a catalyst of explorative and evaluative processes for creativity development at the school. Magíster en Educación Maestría
- Published
- 2017
48. Construção de modelos de árvores arteriais usando diferentes expoentes para a lei de bifurcação
- Author
-
Meneses, Lucas Diego Mota, Queiroz, Rafael Alves Bonfim de, Rocha, Bernardo Martins, Goliatt, Priscila Vanessa Zabala Capriles, and Núñez, Yoisell Rodríguez
- Subjects
Optimization ,CCO ,Computational model ,Árvore arterial ,Modelo computacional ,Otimização ,CIENCIAS EXATAS E DA TERRA [CNPQ] ,Arterial tree - Abstract
Modelos computacionais de árvores arteriais são utilizados como substratos geométricos em simulações hemodinâmicas. A construção destes modelos é mandatória para adequada representação das redes vasculares periféricas devido à escassez de dados anatômicos destas redes. Os modelos relatados na literatura são classificados em: anatômico, a parâmetro condensado, fractal e otimizados. O crescimento dos modelos fractais e otimizados dependem de uma lei de bifurcação, que controla a relação entre os raios dos vasos envolvidos na bifurcação através de um expoente. Neste trabalho, investiga-se a construção de modelos otimizados inspirados no método CCO (Constrained Constructive Optimization) usando novas abordagens para a escolha do expoente da lei de bifurcação. Estas estratégias são formuladas com funções degrau e sigmoidal dependentes do número de bifurcações proximais. Os dados morfométricos dos modelos são comparados com outros experimentais e teóricos da literatura. Os resultados obtidos comprovam que o expoente de bifurcação influencia nas estruturas geométrica e topológica dos modelos. Computational models of arterial trees are used as geometric substrates in hemodynamic simulations. The construction of these models is mandatory for appropriated representation of the peripheral vascular networks due to lack of anatomical data of these networks. The models reported in the literature are classified into: anatomical, lumped parameter, fractal and optimized. The growth of the fractal and optimized models depend on a bifurcation law, which controls the relationship between the radii of the vessels involved in the bifurcation through an exponent. This work investigates the construction of optimized models inspired by the CCO (Constructive Constrained Optimization) method using new approaches to the choice of the exponent of the bifurcation law. Theses strategies are formulated as step and sigmoid functions depend on number of proximal bifurcations. Morphometric data from models are compared with other experimental and theoretical data of the literature. The results obtained show that the bifurcation exponent influences the geometrical and topological structures of the models.
- Published
- 2016
49. Um modelo computacional baseado em análise de decisão multicritério para priorização na alocação de recursos: uma aplicação ao caso das comunidades ribeirinhas da cidade de Coari-AM
- Author
-
Magalhães, Elionai de Souza and Chiwiacowsky, Leonardo Dagnino
- Subjects
Multi-criteria analysis ,Computational model ,Decision model ,Alocação de recursos ,Modelo de decisão ,Modelo computacional ,Ciências Exatas e da Terra::Ciência da Computação [ACCNPQ] ,TOPSIS ,Resource allocation ,Análise multicritério - Abstract
Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-06-13T13:42:00Z No. of bitstreams: 1 Elionai de Souza Magalhães_.pdf: 2039789 bytes, checksum: 5d3f44b9164f4c68bcb09e63c3a2dda0 (MD5) Made available in DSpace on 2016-06-13T13:42:00Z (GMT). No. of bitstreams: 1 Elionai de Souza Magalhães_.pdf: 2039789 bytes, checksum: 5d3f44b9164f4c68bcb09e63c3a2dda0 (MD5) Previous issue date: 2016-03-04 IFAM - Instituto Federal de Educação, Ciência e Tecnologia do Amazonas A responsabilidade de tomar decisões em si não é fácil, e quando está relacionada à gestão de recursos na área pública é uma tarefa ainda mais difícil, pois está ligada a um alto nível de complexidade. Neste trabalho, é apresentado um modelo computacional baseado em análise de decisão multicritério para a priorização da alocação de recursos financeiros para as comunidades ribeirinhas da região de Coari, Amazonas. Com o surgimento da Pesquisa Operacional, foi possível o desenvolvimento de métodos que auxiliam os tomadores de decisão no que se refere à avaliação e escolha em ambientes que envolvem multicritérios. É o caso da gestão pública, cuja decisão sobre a alocação de recursos passa pela análise de diversos critérios. As técnicas de decisão multicritério, aliadas às novas tecnologias de informação e comunicação, possibilitam novas formas de conhecimento e maior qualidade em diversos serviços. O emprego destas tecnologias no desenvolvimento de ferramentas de auxílio à decisão para a alocação de recursos é de grande utilidade, tendo em vista a automação no processo de análise e rapidez na obtenção dos resultados, possibilitando agilidade na tomada de decisão. Neste trabalho, é desenvolvido um modelo computacional baseado na técnica de Auxílio à Decisão Multicritério para ajudar na alocação de recursos públicos em comunidades ribeirinhas do Amazonas. O modelo emprega a técnica TOPSIS de análise multicritério com o intuito de obter um ranking das comunidades, para assim indicar aquela com maior grau de prioridade para receber a alocação de recursos públicos. Os experimentos foram realizados assumindo um conjunto de seis critérios empregados na ordenação de oito regiões de comunidades ribeirinhas. No estudo realizado, a lista de priorização indicou a região de comunidades do Baixo Solimões como a prioritária para a alocação de recursos públicos e a robustez da priorização obtida na aplicação efetuada foi avaliada através da realização de uma análise de sensibilidade. The responsibility of making decisions itself is not easy, and when it is related to the management of resources in the public sector is an even more difficult task, because it is linked to a high level of complexity. In this paper, we present a computational model based on multi-criteria decision analysis to prioritize the allocation of financial resources to the coastal communities of Coari region of Amazonas. With the emergence of Operational Research, development methods was possible that assist decision makers with regard to the evaluation and choice in environments that involve advanced. This is the case of public administration, whose decision on the allocation of resources involves the analysis of various criteria. The techniques of multi-criteria decision, combined with the new technologies of information and communication, enable new forms of knowledge and higher quality in different services. The use of these technologies in the development of the decision support tools for the allocation of resources is useful in view of automation in the process of analysis and speed in obtaining results, enabling agility in decision making. In this work, we developed a computational model based on the technique of Aid to Decision Multicriteria to assist in the allocation of public resources in riverine communities of Amazonas. The model uses the TOPSIS technique of multi-criteria analysis in order to obtain a ranking of the communities, so as to indicate that more priority to receive the allocation of public resources. The experiments were performed assuming a set of six criteria used in the ordination of eight regions of riverside communities. In the study, the list of priority indicated the region of the Lower Solimões communities as a priority for the allocation of public resources and the robustness of the obtained priority in the application made was assessed by performing a sensitivity analysis.
- Published
- 2016
50. Análisis del efecto de la cafeína en un modelo computacional de neurona dopaminérgica, en relación a la enfermedad de Parkinson
- Author
-
Gaitán Vaca, Diana Milena and Pinzón Velasco, Andres Mauricio
- Subjects
Neurona dopaminérgica ,Dopaminergic neuron ,Cafeína ,51 Matemáticas / Mathematics ,Caffeine ,Computational model ,0 Generalidades / Computer science, information and general works ,61 Ciencias médicas ,Medicina / Medicine and health ,Modelo computacional ,Parkinson - Abstract
La enfermedad de Parkinson es la segunda enfermedad neurodegenerativa de mayor importancia en el mundo después de la enfermedad de Alzheimer, afectando entre el 1% de los adultos mayores de 65 años y el 2% de los adultos mayores de 85 años. Numerosos estudios han encontrado una relación inversa entre el consumo de cafeína y el riesgo de desarrollar la enfermedad de Parkinson, adicionalmente, se ha comprobado que la cafeína tiene la capacidad de proteger a las neuronas dopaminérgicas de la degeneración inducida por distintas neurotoxinas, mejorando su viabilidad. Con el fin de dilucidar los posibles mecanismos de neuroprotección mediados por la cafeína, se desarrolló un modelo computacional tejido específico, del conjunto de reacciones bioquímicas propias de la neurona dopaminérgica tomando como base el conjunto de reacciones de neurona que dan flujo a la función objetivo de mantenimiento celular, se añadieron los componentes de síntesis y transporte de dopamina, para la simulación de neurona saludable y neurona con Parkinson, utilizando como evidencia datos de expresión de genes, a partir de muestras postmortem de sustancia nigra en pacientes con Parkinson y controles. Se simularon 4 escenarios diferentes: neurona saludable, neurona saludable + cafeína, neurona Parkinson y neurona Parkinson + cafeína. Como resultado a estos cuatro escenarios se encontró que para el fenotipo metabólico de neurona saludable + cafeína hubo un aumento en el transporte de dopamina vía sodio (9,3 μM·h-1 a 37,6 μM·h-1), a comparación con el fenotipo encontrado en el modelo de neurona Parkinson + cafeína, donde los niveles de trasporte de dopamina vía sodio fueron constantes, pero mucho menores (-7,43 μM·h-1 a -7,43 μM·h-1). Con respecto a los escenarios con cafeína negativa, utilizados como control en ambos escenarios, se hallaron valores de flujo de (10 μM·h-1) para el modelo saludable y de (-8 μM·h-1) para el modelo Parkinson. Por lo tanto, teniendo en cuenta estos resultados, se puede inferir principalmente que, la cafeína no muestra efectos negativos en el mantenimiento celular de la neurona, y por ende no hay ni muerte celular, ni deficiencia en su metabolismo, por lo que la neurona no se ve afectada de manera negativa con la presencia de esta sustancia. Abstract. Parkinson's disease is the second most important neurodegenerative disease in the world after Alzheimer's disease, affecting between 1% of adults over 65 years and 2% of adults over 85 years. Numerous studies have found an inverse relationship between caffeine intake and the risk of developing Parkinson's disease; in addition, caffeine has been shown to have the ability to protect dopaminergic neurons from neurotoxin-induced degeneration, improving their viability. In order to elucidate the possible mechanisms of neuroprotection mediated by caffeine, a tissue-specific computational model was developed from the set of biochemical reactions typical of the dopaminergic neuron based on the set of neuronal reactions that give flux to the objective function of cellular maintenance, also, dopamine synthesis and transport reactions were added. For healthy neuron and Parkinson neuron simulation were used evidence of gene expression from postmortem substantia nigra samples in Parkinson patients and controls. Four different scenarios were simulated: healthy neuron, healthy neuron + caffeine, Parkinson's neuron and Parkinson's neuron + caffeine. As a result of these four scenarios it was found that for the metabolic phenotype of healthy neuron + caffeine there was an increase in the transport of dopamine via sodium (9.3 µM·h-1 to 37.6 µM·h-1 ), compared with the phenotype found in the Parkinson + caffeine simulation, where levels of dopamine transport via sodium were constant but much lower (-7.43 µM·h-1 to -7.43 µM·h-1 ). With regard to negative caffeine scenarios, used as controls, flux values of (10 µM·h-1 ) were found for the healthy model and (-8 µM·h-1 ) for the Parkinson model. Therefore, taking into account these results, it can be inferred mainly that, caffeine does not show negative effects on the cellular maintenance of the neuron, and therefore there is neither cell death nor deficiency in its metabolism, so the neuron Is not negatively affected by the presence of this substance. Maestría
- Published
- 2016
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.